HomeMy WebLinkAboutStaff Report 2407-32344.Recommendation to Council to Accept the City of Palo Alto One Water Plan (Action 8:15
PM – 9:15 PM) Staff: Karla Dailey
Utilities Advisory Commission
Staff Report
From: Dean Batchelor, Director Utilities
Lead Department: Utilities
Meeting Date: January 7, 2025
Report #: 2407-3234
TITLE
Recommendation to Council to Accept the City of Palo Alto One Water Plan
RECOMMENDATION
This item is for discussion and action is requested to recommend to the City Council to accept
the City of Palo Alto One Water Plan.
EXECUTIVE SUMMARY
The One Water Plan (OWP) presents a vision and achievable path toward meeting the City’s
long-term water supply and water conservation goals by identifying alternatives for the City
that, if implemented, may mitigate the impact of future water supply uncertainties such as
severe multi-year drought, changes in climate, water demand, and regulations.
The OWP compares potential water supply and water conservation portfolios given the City’s
weighted evaluation criteria, and provides an initial analysis of alternatives and a framework
within which Council can make decisions now and in the future about which types of projects
the City may want to explore further. Additionally, this work effort developed an excel-based
tool that staff can use to evaluate and prioritize water supply and water conservation
portfolios. Palo Alto can use these flexible planning tools now and to adjust its overall water
supply strategy as the future unfolds, conditions change and uncertainties are resolved. The
OWP water supply and conservation options and the resulting portfolios that scored highest
given the rough cost estimates and evaluation criteria include:
•Portfolio A – Baseline: Existing potable water supply from the Hetch Hetchy Regional
Water System (RWS);
•Portfolio B – Baseline with enhanced water conservation;
•Portfolio C: Baseline with enhanced conservation plus desalinization;
•Portfolio D: Baseline with enhanced conservation plus groundwater;
Table 1: Ongoing and Planned Conservation versus Enhanced Conservation Phases 1 and 2
Each portfolio C through G includes Enhanced Conservation Phase 1 and Phase 2 measures, plus
one local water supply infrastructure project, with the remainder of the water supplied by the
RWS.
•Portfolio C adds a Bay Water Desalination plant that would supply 4,480 acre feet per
year of water during a normal year.
•Portfolio D adds groundwater. Under this portfolio, the City would equip two of the
existing emergency supply wells with treatment facilities and convert these from
emergency supply to regular potable use. The wells would provide 2,250 acre feet (af)
per year of water supply during a normal year. Notably, Valley Water’s 10-year
projection anticipates that the groundwater production charge will more than double
from the 2023 rate of $1,724/af to $4,147/af by 2032, reflecting approximately 9.5
percent annual escalation. Valley Water expects this increase to primarily pay for critical
capital program needs including water treatment plant upgrades and dam seismic
retrofit work. For reference, SFPUC’s expected rate in 2032, assumed in the OWP, is
$2,630/af.
•Portfolio E adds a Palo Alto Direct Potable Reuse (DPR) facility that would supply 4,723
acre feet per year of water during a normal year.
•Portfolio F adds a Palo Alto Indirect Potable Reuse (IPR) water purification facility with
groundwater injection wells. This Indirect Potable Reuse facility would supply 5,150 acre
feet per year of water supply during a normal year.
•Portfolio G adds a Regional DPR water purification facility constructed by Valley Water
and located in Palo Alto instead of a dedicated Palo Alto DPR facility. The estimated
water supply from this facility for Palo Alto is 1,769 acre feet per year during a normal
year.
Figure 1 illustrates the water supply and demand for each portfolio during a normal year in
2045.
Figure 1: Normal Year Supply and Demand Analysis by Portfolio in 2045
The OWP calculates a weighted average unit cost for each portfolio considering the volume of supply
from each water supply source during a normal year. Table 1 shows the weighted average unit cost for
each portfolio in 2023 dollars and 2045 dollars. The cost estimates generated for the OWP are planning-
level or order-of-magnitude cost estimates with a typical estimating accuracy of -50% to +100% due to
limited level of project information often coupled with significant uncertainties at this planning stage. The
weighted average unit costs are calculated based upon these cost estimates and are not rounded for
consistency across the OWP and appendices.
Table 2 – Estimated Weighted Average Unit Cost of Water for Portfolio A through Portfolio G
Estimated Weighted Average Unit Cost
($/Acre Foot)
Portfolio Name
2023 Dollars 2045 Dollars
Portfolio A - Baseline $2,210 $4,088
Portfolio B – Enhanced Conservation Phase 1 and 2 $2,075 $3,093
Portfolio C – Enhanced Conservation Phase 1 and 2
with Bay Water Desalination
$3,854 $6,663
Portfolio D – Enhanced Conservation Phase 1 and 2
with Groundwater
$2,556 $5,330
Portfolio E – Enhanced Conservation Phase 1 and 2
with Palo Alto DPR
$2,645 $4,938
Portfolio F – Enhanced Conservation Phase 1 and 2
with Palo Alto IPR
$3,323 $6,440
Portfolio G – Enhanced Conservation Phase 1 and 2
with Regional DPR
$2,355 $4,552
Table 3 - Evaluation Results - Weighted Criteria Scores By Portfolio
Criteria Sub-Criteria Criteria
Weight
A.
Baseline
B. Enhanced
Conservatio
n Phase 1
and 2
C. Enhanced
Conservation
with Bay
Water
Desalination
D. Enhanced
Conservatio
n with
Groundwate
r
E. Enhanced
Conservatio
n with Palo
Alto DPR
F. Enhanced
Conservatio
n with Palo
Alto IPR
G. Enhanced
Conservation
with Regional
DPR
Estimated
Portfolio
Weighted Unit
Cost in 2045
($/AF)
--$4,088 $3,903 $6,663 $5,330 $4,938 $6,440 $4,552
Estimated Start
Year
--2025 2025 2035 2025/2030 2035 2030 2040
Unit Cost Unit Cost 20%0.95 1.00 0.20 0.59 0.70 0.26 0.81
Reliability Reliability 35%0.35 0.60 1.43 0.85 1.39 1.37 0.90
Efficient Use of
Water
10%0.20 0.23 0.27 0.23 0.31 0.27 0.26
Ecological
Benefit
10%0.20 0.22 0.19 0.24 0.22 0.22 0.22
Reliance on
Tuolumne
10%0.10 0.14 0.29 0.21 0.29 0.31 0.20
Environmental
Benefits
Subtotal 30%0.50 0.59 0.75 0.68 0.82 0.80 0.68
Implementatio
n Timeline
5%0.25 0.24 0.17 0.22 0.16 0.18 0.21
Operational
Complexity
5%0.25 0.24 0.17 0.22 0.17 0.18 0.24
Public
Acceptance
5%0.25 0.24 0.21 0.22 0.19 0.20 0.22
Ease of
Implementation
Subtotal 15%0.75 0.72 0.55 0.66 0.52 0.56 0.67
Total 100%2.55 2.91 2.91 2.78 3.43 2.99 3.06
Notes:
(1) Based on estimated year 2045.
(2) Portfolio G (Enhanced Conservation with Regional DPR) assumes that Valley Water does exercise its option to transfer a portion
of RWQCP treated effluent (selected “Yes” in the Tool). All other portfolios assume that Valley Water does not exercise its option
(selected “No” in the Tool).
(3) The weighted criteria scores are normalized to a scale of 1-5.
Page 10 of 13
Portfolio Evaluation Summary
Figure 2 compares the portfolios dependency on the Valley Water Transfer option decision.
Figure 2. Portfolio Results and Dependence on Valley Water Option to Transfer Decision
Sensitivity Analysis
The OWP includes a sensitivity analysis to identify how or if the findings change when the
evaluation criteria are weighted differently. The sensitivity analysis showed that if Valley Water
does not exercise the option to transfer a portion of Treated Effluent from the RWQCP,
Portfolio E (Enhanced Conservation Phase 1 and 2 and Palo Alto DPR) remains the top scoring
portfolio regardless of changes in cost or reliability criteria and usually outperforms other
portfolios. The only case where Portfolio E (Enhanced Conservation with Palo Alto DPR) is not
the portfolio with the highest weighted criteria score is when unit cost has additional weighting.
Portfolio B (Enhanced Conservation Phase 1 and 2) becomes the highest scoring portfolio and
the baseline portfolio scores lower but very close to Portfolio E. In this case, the Palo Alto DPR
facility is still the most favorable infrastructure investment compared with the other local
supply options, however, considering affordability and the cost of the facility relative to other
benefits, Palo Alto may want to continue with baseline Portfolio A or implement enhanced
conservation measures instead.
In the event that Valley Water exercises the option to transfer a portion of treated effluent
from the RWQCP, Portfolio G (Enhanced Conservation with Regional DPR) scores the highest.
However, if unit cost is weighted less heavily and supply reliability is weighted more heavily,
Portfolio C (Enhanced Conservation with Bay Water Desalination) scores higher than Portfolio G
(Enhanced Conservation with Regional DPR). With a lower Reliability criteria weighting,
Portfolio B (Enhanced Conservation Phase 1 and Phase 2) is the top scoring portfolio.
Additionally, if unit cost is given additional weight, Portfolio C (Enhanced Conservation with Bay
Page 11 of 13
Water Desalination) scores lower than all other options, including Baseline Portfolio A, while
Portfolio B (Enhanced Conservation Phase 1 and 2) is the top scoring portfolio and Portfolio G
(Enhanced Conservation with Regional DPR) is the top scoring supply infrastructure portfolio.
FISCAL/RESOURCE IMPACT
There is no staff recommendation to proceed with any specific project at this time so there is
no financial resource impact resulting from Council acceptance of the OWP. However, the OWP,
cost estimates, and Evaluation Tool provide an adaptable roadmap for the City’s water strategy.
To illustrate the potential rate impacts for water utility customers stemming from the various
portfolios in the OWP, staff utilized the projected weighted unit costs for each portfolio in FY
2045 as the basis for Palo Alto's water purchase costs. This was coupled with an assumed
average annual rate increase of 6% for the distribution system. All other assumptions are the
same as outlined in the OWP. This analysis does not take into consideration other unexpected
costs that may impact the cost of water and does not consider sensitivities to demand changes.
This analysis is for illustration purposes only, and provides an approximation of the relative rate
impact of different portfolio average unit costs (from Table 1) under the assumptions stated in
the OWP. For reference, under Palo Alto’s current rates in FY 2025, a residential monthly bill at
9 CCF of water usage costs $113.47. Also shown is the capital cost associated with each
portfolio.
Table 4 – Residential Monthly Bills in FY 2045 for Each OWP Portfolio
This analysis indicates that the difference in residential bills across the portfolios relative to the
baseline Portfolio A ranges from negative 1% for the least expensive Portfolio B (Enhanced
Conservation Phase 1 and 2) to 17% for the most expensive Portfolio C – Enhanced
Conservation with Bay Water Desalination. Note that capital costs are planning level and actual
costs are -50% to 100% of estimated.
Page 12 of 13
STAKEHOLDER ENGAGEMENT
The following is a timeline of public meetings and community workshops on the OWP to date:
- July 7, 2021 - the Utilities Advisory Commission (UAC) reviewed a draft objectives, scope,
and community engagement plan for the OWP (Staff Report #12332)5
- November 2021 - Palo Alto Utilities Department in collaboration with the Public Works
Department issued OWP Request For Proposals
- June 2022 - Council approved the contract with Carollo Engineers to develop the OWP
(Staff Report 13434)6
-September 28, 2022 - First Community Workshop, Community Needs and Priorities7
-December 6, 2022 - Second Community Workshop Exploring Water Supply and Water
Conservation Options8
- February 1, 2023 - staff provided an update to the UAC on the development of the OWP
(Staff Report 14974)9
- June 3, 2024 - staff provided an update to the UAC on the OWP background, goals,
approach, overview and initial results (Staff Report 2404-2968)10
Additionally, at the UAC meeting on November 6, 2024, Palo Alto’s water supplier, SFPUC’s
Assistant General Manager of the Water Enterprise, Steve Ritchie provided an overview of the
RWS and SFPUC’s planning efforts including drought planning and Alternative Water Supply
Program. At the same UAC meeting, the Bay Area Water Supply and Conservation Agency
CEO/General Manager, Nicole Sandkulla also presented additional information on water supply,
water conservation and reliability. This provides additional regional context for the Palo Alto
OWP, which focuses on the local area within the Palo Alto city limits.
ENVIRONMENTAL REVIEW
The development of the OWP is not a project requiring California Environmental Quality Act
review, because it is an administrative governmental activity which will not cause a direct or
indirect physical change in the environment.
5 Staff Report 12332: https://www.cityofpaloalto.org/files/assets/public/agendas-minutes-reports/agendas-
minutes/utilities-advisory-commission/archived-agenda-and-minutes/agendas-and-minutes-2021/07-07-2021-
special/id-12332-item-1.pdf
6 Staff Report 13434: https://www.cityofpaloalto.org/files/assets/public/v/11/agendas-minutes-reports/agendas-
minutes/city-council-agendas-minutes/2022/20220620/20220620pccsm-amended-final-final.pdf
7 Presentation and results from the live polling:
https://www.cityofpaloalto.org/files/assets/public/v/1/utilities/water-drought/stakeholder-mtg-1-community-
meeting.pdf
8 Slides: https://www.cityofpaloalto.org/files/assets/public/v/1/utilities/water-drought/stakeholder-workshop-
2_community.pdf Recording: https://youtu.be/YEguKgxzRNY
9 Staff Report 14974: https://www.cityofpaloalto.org/files/assets/public/v/1/agendas-minutes-reports/agendas-
minutes/utilities-advisory-commission/archived-agenda-and-minutes/agendas-and-minutes-2023/02-feb-2023/02-
01-2023-uac-agenda-and-packet.pdf
10 Staff Report 2404-2968 https://www.cityofpaloalto.org/files/assets/public/v/2/agendas-minutes-
reports/agendas-minutes/utilities-advisory-commission/archived-agenda-and-minutes/agendas-and-minutes-
2024/06-jun-2024/06-03-2024-packet-v2.pdf
Page 13 of 13
ALTERNATIVE ACTIONS
Upon Council acceptance of the City of Palo Alto OWP, staff will have access to the cost
estimate spreadsheet (shown in OWP Appendix C) and the Tool (shown in OWP Appendix E).
The OWP, cost estimates and Tool together provide a framework within which Council can
make decisions now and in the future about the City’s water supply and conservation portfolio,
including which types of projects the City may want to explore further or to adjust the City’s
overall water supply strategy to meet potentially changing future conditions.
ATTACHMENTS
Attachment A: Presentation (will be published 1/7/2025)
Attachment B: One Water Plan
AUTHOR/TITLE:
Alan Kurotori, Utilities Chief Operating Officer
Staff: Karla Dailey, Assistant Director of Utilities, Resource Management Division
January 7, 2025 www.cityofpaloalto.org
One Water Plan
Utilities Advisory Commission (UAC)
2 www.cityofpaloalto.org
1.One Water Plan Vision
2.Review One Water Portfolios
3.June 2024 UAC Meeting Follow-up
4.Currently Planned Activities
5.Important Events and Dates
6.Recommendation
One Water Plan (OWP) Agenda
More information at cityofpaloalto.org/water
3 www.cityofpaloalto.org
One Water Plan (OWP) Vision
One Water Plan is a framework for Council to make decisions
about Palo Alto’s future water supply and water conservation
portfolio, if reliability becomes a concern
Time horizon is 20 years; 2045
4 www.cityofpaloalto.org
One Water Portfolio with Supply and Conservation Alternatives
A: Baseline; San Francisco Public Utilities Commission Regional Water System Water Supply
B: SFPUC + Enhanced Conservation Phases 1 &2
C: SFPUC + Enhanced Conservation + Bay Water Desalinization
D: SFPUC+ Enhanced Conservation + Groundwater (with treatment)
E: SFPUC + Enhanced Conservation + Palo Alto-owned Direct Potable Reuse (DPR)
F: SFPUC + Enhanced Conservation + Indirect Potable Reuse (IPR)
G: SFPUC+ Enhanced Conservation + Regional Direct Potable Reuse (DPR)
Review of One Water Portfolios
5 www.cityofpaloalto.org
June 2024 One Water Plan Follow-Up
Commissioner Question: What problem are we
trying to solve?
•Comprehensive look at relative ease of implementation, environmental benefits, reliability, and cost of various supply augmentation and conservation alternatives
•Common understanding of water supply vision amongst stakeholders
•Eliminates fragmented analysis; ie “what about looking at XYZ?”
•Dynamic - includes a tool that can be updated in the future
•Identifies project types that are most likely to be attractive
•Not intended to be a detailed feasibility analysis
6 www.cityofpaloalto.org
June 2024 One Water Plan Follow-Up
Commissioner Comment: Rate Impact Should be Considered
•Illustrative future bill implications of selecting each of the OWP portfolios range from a decrease of 1% to an increase of 17% in FY 2045.
•Project costs are planning level (actual capital cost is -50% to +100%)
Portfolio Capital Cost
($M)
FY 2045
Bill Difference from
Portfolio A - Baseline
Residential
Monthly Bill
(9 CCF)
$ %
A: Baseline (SFPUC) $0 $313
B: Enhanced Conservation $0 $309 -$4 -1%
C: Enhanced Conservation + Desal $381 $366 $53 17%
D: Enhanced Conservation + Groundwater $53 $339 $26 8%
E: Enhanced Conservation + Palo Alto DPR $159 $331 $18 6%
F: Enhanced Conservation with IPR $240 $362 $49 16%
G: Enhanced Conservation + Regional DPR $29 $323 $10 3%
7 www.cityofpaloalto.org
June 2024 One Water Plan Follow-Up
Commissioner Comment: Consider the Intermittent
Use of Groundwater During Drought
City planning to
modify two
emergency
groundwater wells
to enable blending
with SFPUC water
8 www.cityofpaloalto.org
June 2024 One Water Plan Follow-Up
Commissioner Question: Is the OWP Trigger-Based?
Trigger-Based Implementation Roadmap
Water Supply Reliability Concern
Valley Water Exercised Effluent
Transfer option
9 www.cityofpaloalto.org
June 2024 One Water Plan Follow-Up
Additional Commissioner
Questions/Comments
Response
Are contaminants a concern for some of
the identified water supply alternatives?
Possibly and increased risk of contaminants is an important consideration.
Before any project is recommended, the risk of contaminants will be
evaluated.
Linear weighting of the evaluation
criteria is not ideal
Staff will consider other methodologies in the next OWP iteration.
Community is not ready for Direct
Potable Reuse
Outreach and education are crucial to public acceptance of new water
supplies. As SFPUC and Valley Water are considering adding water reuse to
their systems, Palo Alto will engage and collaborate with the rest of the
region regarding water reuse education outreach.
Tiered water rates should be
reconsidered
Yes, water rates are an important part of managing a water utility. Rate
structures will be considered in the next cost of service analysis.
Tree canopy and vegetation impacts of
drought
Agreed, this is a very important topic to consider in any discussion of water
supply particularly during water scarcity. Any recommendation of a water
supply or conservation alternative will include an assessment of the impact
on trees and other vegetation.
10 www.cityofpaloalto.org
Currently Planned Activities
•Implement ongoing/planned conservation
•Explore Enhanced Conservation measures
•Monitor funding opportunities
11 www.cityofpaloalto.org
Important Events and Dates that May
Warrant Revisiting One Water Plan
•2027: SFPUC updated Alternative Water Supply Plan
•2032: Valley Water decision regarding option to transfer effluent from
RWQCP for south Santa Clara County uses
•State decision regarding Bay Delta Plan implementation
•Other events or conditions affecting water supply reliability or cost
•New water supply technologies or regional partnership opportunities
12 www.cityofpaloalto.org
Action
UAC Recommendation to Council to Accept the City of Palo
Alto One Water Plan
* Scheduled for Council March 2025
* There is no recommendation to proceed with any specific project in the OWP;
there is no resource impact resulting from Council acceptance of the OWP
* Future water supply and conservation recommendations will build upon the work
in this OWP
One Water Plan
FINAL / October 2024
Digitally signed by Inge Wiersema
Contact Info: Carollo Engineers, Inc.Date: 2024.10.24 17:06:46-07'00'
OCTOBER 2024 / FINAL / CAROLLO
Contents
EXECUTIVE SUMMARY
ES.1 Plan Purpose ES-1
ES-1
ES-1
ES-2
ES-2
ES-3
ES.2 Study Area and Planning Horizon
ES.3 Stakeholder Engagement
ES.4 Water Demand Forecast
ES.5 Existing Water Supplies
ES.6 Potential Water Conservation and Supply Options
ES.6.1 Options Screening
ES.6.2 Options Evaluation
ES-3
ES-5
ES.7 Portfolio Evaluation ES-8
ES.7.1 Evaluation Tool
ES.7.2 Demand and Supply Balance by Portfolio
ES.7.3 Portfolio Evaluation Results
ES-8
ES-8
ES-10
ES.8 Trigger Based Implementation Roadmap
ES.9 Next Steps
ES-12
ES-12
CHAPTER 1 INTRODUCTION
1.1
1.2
1.3
1.4
1.5
1.6
Plan Purpose 1-1
1-1
1-3
1-5
1-5
1-5
Motivations for Development of a One Water Plan
Key Previous Planning Efforts
Geographical Study Area
Planning Period
Stakeholder Engagement
1.6.1 Community Engagement
1.6.2 City Departments
1.6.3 Regional Partners
1-7
1-7
1-8
1.7
1.8
Report Organization
Acknowledgements
1-8
1-9
CHAPTER 2 WATER DEMANDS AND SUPPLIES
2.1 Current and Projected Demands 2-1
2.1.1 Historical and Existing Water Demands
2.1.2 Future Demand Projections
2-1
2-2
2.2
2.3
Water Supply History
Existing Water Supply Sources
2-4
2-5
2.3.1 San Francisco RWS Supply
2.3.2 Recycled Water
2-5
2-8
2.3.3 Deep Aquifer Groundwater 2-10
2.4 Conservation Programs 2-14
CITY OF PALO ALTOONE WATER PLAN ii
pw://Carollo/CA/Palo Alto/201363-000000/03 Reports and Studies/02 Deliverables/Final OWP/One Water Plan
OCTOBER 2024 / FINAL / CAROLLO
CHAPTER 3 POTENTIAL OPTIONS
3.1
3.2
3.3
Evaluation Process Overview
Pre-Screening
Screening Criteria
3-1
3-2
3-3
3.3.1 Unit Cost
3.3.2 Estimated Yield
3.3.3 Supply Reliability
3-3
3-3
3-4
3.4 Screening 3-4
3.4.1 RWS Supply 3-5
3-63.4.2 Enhanced Water Conservation – Phase 1
3.4.3 Enhanced Water Conservation - Phase 2
3.4.4 Groundwater
3-10
3-13
3-19
3-22
3-25
3-28
3-30
3-32
3-34
3-36
3-38
3-41
3-44
3.4.5 New Irrigation Wells
3.4.6 DPR with Palo Alto Facility
3.4.7 DPR with Palo Alto Facility and the SSRF
3.4.8 DPR with Regional Facility
3.4.9 IPR with Groundwater Injection
3.4.10 NPR with Phase 3 Extension to Foothills
3.4.11 Graywater Capture and Reuse
3.4.12 Residential Rainwater Capture
3.4.13 Green Stormwater Infrastructure
3.4.14 Multi-Source Storage
3.4.15 San Francisco Bay Desalination
3.5 Options Costs and Screening Conclusions 3-46
CHAPTER 4 OPTION EVALUATION
4.1
4.2
Introduction
Evaluation Criteria
4-1
4-2
4.2.1 Reliability
4.2.2 Unit Cost
4.2.3 Environmental Benefits
4.2.4 Ease of Implementation
4-3
4-3
4-4
4-6
4.3
4.4
Criteria Weighting
Option Evaluation
4-8
4-9
4.4.1 RWS Supply 4-9
4-10
4-11
4-12
4-14
4-15
4-17
4-18
4-20
4.4.2 Enhanced Water Conservation – Phase 1
4.4.3 Enhanced Water Conservation – Phase 2
4.4.4 Groundwater
4.4.5 DPR with Palo Alto Facility
4.4.6 DPR with Regional Facility
4.4.7 DPR with Palo Alto Facility and SSRF
4.4.8 IPR with Groundwater Injection
4.4.9 Bay Water Desalination
CITY OF PALO ALTOONE WATER PLAN iii
OCTOBER 2024 / FINAL / CAROLLO
4.5 Option Evaluation Summary 4-21
4.5.1 Results without Valley Water Transfer
4.5.2 Results with Valley Water Transfer
4-23
4-23
CHAPTER 5 PORTFOLIO DEVELOPMENT AND EVALUATION
5.1
5.2
Portfolio Approach
Portfolio Development
5-1
5-2
5.2.1 Portfolio A – Baseline
5.2.2 Portfolio B – Enhanced Conservation Phase 1 and 2
5-3
5-3
5.2.3 Portfolio C –Enhanced Conservation Phase 1 and 2 with Bay Water Desalination
5.2.4 Portfolio D – Enhanced Conservation Phase 1 and 2 with Groundwater
5.2.5 Portfolio E –Enhanced Conservation Phase 1 and 2 with Palo Alto DPR
5.2.6 Portfolio F – Enhanced Conservation Phase 1 and 2 with IPR
5-4
5-5
5-6
5-7
5-85.2.7 Portfolio G –Enhanced Conservation Phase 1 and 2 with Regional DPR
5.3
5.4
Evaluation Tool 5-9
5.3.1 Data Inputs
5.3.2 User Selections
5.3.3 Tool Outputs
5-11
5-11
5-12
Portfolio Evaluation Results 5-13
5.4.1 Portfolio A - Baseline
5.4.2 Portfolio B – Enhanced Conservation Phase 1 and 2
5-16
5-17
5-17
5-17
5-18
5-18
5-18
5.4.3 Portfolio C – Enhanced Conservation Phase 1 and 2 with Bay Water Desalination
5.4.4 Portfolio D – Enhanced Conservation Phase 1 and 2 with Groundwater
5.4.5 Portfolio E – Enhanced Conservation Phase 1 and 2 with Palo Alto DPR
5.4.6 Portfolio F – Enhanced Conservation Phase 1 and 2 with IPR
5.4.7 Portfolio G – Enhanced Conservation Phase 1 and 2 with Regional DPR
5.5
5.6
Portfolio Evaluation Comparisons 5-19
5.5.1 Portfolio Scores
5.5.2 Portfolio Supply Mix and Unplanned Shortfalls
5.5.3 Portfolio Costs
5-19
5-21
5-23
5-265.5.4 Valley Water Transfer Decision
Sensitivity and Scenario Analysis 5-28
5.6.1 Unit Cost Criterion
5.6.2 Reliability Criterion
5.6.3 Environmental Benefit Criterion
5.6.4 Ease of Implementation Criterion
5.6.5 Demand Scenario
5-28
5-29
5-30
5-31
5-32
5-325.6.6 RWS Supply Cutback and Shortage Stage Scenarios
5.7 Conclusions 5-34
5.7.1 Scoring Results
5.7.2 Supply Reliability
5.7.3 Implementation Considerations
5-34
5-34
5-35
CITY OF PALO ALTOONE WATER PLAN iv
OCTOBER 2024 / FINAL / CAROLLO
CHAPTER 6 ONE WATER IMPLEMENTATION PLAN
6.1
6.2
Prioritized Portfolios
Trigger-Based Implementation
6-1
6-4
6.2.1 Trigger 1: Increase Supply Reliability
6.2.2 Trigger 2: Valley Water Transfer Option
6-5
6-6
6.3 Trigger-Based Implementation Roadmap 6-7
6.3.1 Enhanced Conservation Phase 1 and Phase 2
6.3.2 Groundwater
6-9
6-9
6.3.3 Direct Potable Reuse Options
6.3.4 Other Options
6-10
6-10
6.4 Next Steps 6-11
Appendices
APPENDIX A
APPENDIX B
APPENDIX C
APPENDIX D
APPENDIX E
APPENDIX F
REFERENCES
SUPPLY OPTIONS PRE-SCREENING
COST ESTIMATING DETAILS
SUPPLY PORTFOLIO TOOL DOCUMENTATION
SENSITIVITY ANALYSIS
STAKEHOLDER ENGAGEMENT MATERIALS
Tables
Table ES.1
Table ES.2
Table ES.3
Table ES.4
Table ES.5
Table ES.6
Table ES.7
Table ES.8
Table 2.1
Table 2.2
Table 2.3
Table 2.4
Table 2.5
Table 3.1
Table 3.2
Table 3.3
Table 3.4
Table 3.5
Table 3.6
Table 3.7
Total Water Demand Projections through 2045
Historical and Planned Water Supply Sources through 2045
Pre-screening Results of 27 Initial Options
Options Comparison
Evaluation Criteria Weighting
Option Evaluation Results Summary
ES-2
ES-3
ES-4
ES-5
ES-6
ES-7
ES-8
ES-11
2-3
2-5
2-6
2-9
2-14
3-2
Overview of Options included in each Portfolio
Portfolio Evaluation Summary
Total Water Demand Projections through 2045
Historical and Planned Water Supply Sources through 2045
Tier One Plan Drought Shortage Allocations
Uses of Recycled Water from the RWQCP
Existing Water Conservation Programs
Options Pre-screening Results
Enhanced Conservation - Phase 1 Measures Summary
Enhanced Conservation Phase 2 Measures Summary
Emergency Supply Well Capacities
3-8
3-11
3-15
3-21
3-24
City Park Irrigation Demands
2022 RWQCP Flows by Partner and Flow Available for Reuse
RWQCP Flows Available for Regional Purification Facility and Local Reuse 3-25
CITY OF PALO ALTOONE WATER PLAN v
OCTOBER 2024 / FINAL / CAROLLO
Table 3.8
Table 3.9
Table 3.10
Table 3.11
Table 3.12
Table 4.1
Table 4.2
Table 4.3
Table 4.5
Table 4.6
Table 4.7
Table 4.8
Table 4.9
Table 4.10
Table 4.11
Table 4.12
Table 4.13
Table 4.14
Table 4.15
Table 4.16
Table 4.17
Table 5.1
Table 5.2
Table 5.3
Table 5.4
Table 5.5
Table 5.6
Table 5.7
Table 5.8
Table 5.9
Multi-Source Storage Option Sizing and Cost Estimates
Unit Cost Estimate of all Screened Options - 1
Unit Cost Estimate of all Screened Options - 2
Options Comparison
3-42
3-47
3-48
3-49
3-50
4-5
4-5
4-6
4-8
4-9
4-10
4-11
4-12
4-13
4-15
4-16
4-17
4-19
4-20
4-21
4-22
5-2
Summary of Screening Scores
Efficient Use of Water Sub Criterion Scoring
Ecological Benefits Criterion Score Definitions
Implementation Timeline Sub Criterion Score Definitions
Public Acceptance Sub Criterion Score Definitions
Evaluation Criteria Weighting
RWS Supply Evaluation Results
Enhanced Conservation – Phase 1 Evaluation Results
Enhanced Conservation – Phase 2 Evaluation Results
Groundwater Evaluation Results
DPR with Palo Alto Facility Evaluation Results
DPR with Regional Facility Evaluation Results
DPR with Palo Alto Facility and SSRF Evaluation Results
IPR with Groundwater Injection Evaluation Results
Bay Water Desalination Evaluation Results
Example of Weighted Score Calculation
Option Evaluation Results Summary
Options Evaluation Results Summary
Overview of Options included in each Portfolio 5-3
Projected Yield of Enhanced Water Conservation Phase 1 and 2
Portfolio Evaluation Results – Raw Scores
Portfolio Evaluation Results – Weighted Scores
Unplanned Supply Gap Volumes by Portfolio During Dry Year
Total Estimated Unit Cost by Portfolio
Range of Criteria Weighting in Sensitivity Analysis
Unplanned Supply Gaps under RWS Supply Cutback and Emergency
Shortages
Overview of Options included in each Portfolio
Portfolio Evaluation Summary
Projected Unplanned Supply Gap under various RWS Cutback and Shortage
Scenarios
5-4
5-14
5-15
5-23
5-23
5-28
5-33
6-2
6-2
Table 6.1
Table 6.2
Table 6.3
6-6
Figures
Figure ES.1
Figure ES.2
Figure ES.3
Option Evaluation Process ES-3
ES-9Normal Year Supply and Demand Analysis by Portfolio for 2045
Dry Year Supply and Demand Analysis by Portfolio for 2045 with a 50% RWS
Supply Cutback
Trigger-Based Implementation Roadmap
Palo Alto City Limits
ES-10
ES-12
1-6
Figure ES.4
Figure 1.1
CITY OF PALO ALTOONE WATER PLAN vi
OCTOBER 2024 / FINAL / CAROLLO
Figure 2.1
Figure 2.2
Figure 2.3
Figure 2.4
Figure 3.1
Figure 3.2
Figure 3.3
Figure 3.4
Figure 3.5
Figure 3.6
Figure 3.7
Figure 3.8
Figure 3.9
Figure 3.10
Figure 3.11
Figure 3.12
Figure 3.13
Figure 3.14
Figure 3.15
Figure 3.16
Figure 4.1
Figure 4.2
Figure 4.3
Figure 5.1
Figure 5.2
Figure 5.3
Figure 5.4
Figure 5.5
Figure 5.6
Figure 5.7
Figure 5.8
Figure 5.9
Figure 5.10
Figure 5.11
Figure 5.12
Palo Alto Historical Water Use (1990-2020)
Distribution of Water Use by Customer Type (2020 Data)
Water Demand Projections Through 2045
Emergency Supply Well Locations
Option Evaluation Process
San Francisco Hetch Hetchy RWS
Projected Water Savings from Enhanced Water Conservation – Phase 1
Projected Water Savings from Enhanced Water Conservation – Phase 2
Existing Emergency Supply Wells
Groundwater Treatment Option Schematics
Potential New Irrigation Well Sites
DPR with Palo Alto Treatment Facility and SSRF Option Schematic
DPR with Regional Treatment Facility Option Schematic
IPR with Groundwater Injection Schematic
NPR with Phase 3 Extension to Foothills Schematic
Graywater System “Laundry-to-Landscape” Schematic
Green Stormwater Infrastructure Schematic
Planned Green Stormwater Infrastructure Projects
City Parks Selected for Multi-Source Storage Tank
Small scale Bay Water Desalination for Palo Alto Schematic
Options Evaluation Process
Options Evaluation Results with the Valley Water Transfer
Options Evaluation Results without the Valley Water Transfer
Option Evaluation Process
Normal Year Supply and Demand Projection for Portfolio B
Normal Year Supply and Demand Projection for Portfolio C
Normal Year Supply and Demand Projection for Portfolio D
Normal Year Supply and Demand Projection for Portfolio E
Normal Year Supply and Demand Projection for Portfolio F
Normal Year Supply and Demand Projection for Portfolio G
Evaluation Tool Flow Chart
Weighted Portfolio Scores without the Valley Water Transfer option
Weighted Portfolio Scores with the Valley Water Transfer option
Normal Year Supply and Demand Analysis by Portfolio for 2045
Dry Year Supply and Demand Analysis by Portfolio for 2045 with a 50 percent
RWS Supply Cutback
2-1
2-2
2-4
2-11
3-1
3-5
3-9
3-12
3-14
3-17
3-20
3-26
3-29
3-31
3-33
3-35
3-39
3-40
3-43
3-45
4-1
4-23
4-24
5-1
5-4
5-5
5-6
5-7
5-8
5-9
5-10
5-16
5-16
5-21
5-22
5-24
5-24
5-26
5-29
5-30
5-31
5-32
Figure 5.13
Figure 5.14
Figure 5.15
Figure 5.16
Figure 5.17
Figure 5.18
Figure 5.19
Figure 5.20
Weighted Unit Cost by Portfolio (2023 dollars)
Weighted Unit Cost by Portfolio (2045 dollars)
Portfolio Evaluation Results Schematic with Valley Water Transfer trigger
Results of Sensitivity Analysis for Unit Cost Criterion
Results of Sensitivity Analysis for the Reliability Criterion
Results of Sensitivity Analysis for the Environmental Benefit Criterion
Results of Sensitivity Analysis for the Ease of Implementation Criterion
Dry Year Supply and Demand Analysis by Portfolio for 2045 with a 30 percent
RWS Supply Cutback 5-33
viiCITY OF PALO ALTOONE WATER PLAN
OCTOBER 2024 / FINAL / CAROLLO
Figure 6.1
Figure 6.2
Figure 6.3
Comparison of Weighted Portfolio Evaluation Scores.
Trigger-Based Implementation Roadmap
Projected Yield Trajectory of Enhanced Conservation Phase 1 and 2.
6-3
6-8
6-9
CITY OF PALO ALTOONE WATER PLAN viii
OCTOBER 2024 / FINAL / CAROLLO
Abbreviations
AB Assembly Bill
ADU
af
accessory dwelling units
acre-feet
af/ac
afy
acre feet per acre
acre-feet per year
AWPF
AWS
AWPF
BAF
advanced water purification facility
Alternative Water Supply
Advanced Water Purification Facility
Biologically Active Filtration
Bay Area Water Supply and Conservation Agency
Carollo Engineers
BAWSCA
Carollo
ccf Hundred Cubic Feet
CDPH
CII
California Department of Public Health
Commercial, Industrial, or Institutional
California Environmental Quality Act
Capital Improvement Projects
City of Palo Alto
CEQA
CIP
City
CoRe Plan
DDW
DPR
DSS
Countywide Water Reuse Master Plan
Division of Drinking Water
direct potable reuse
Decision Support System
California Department of Water Resources
Environmental Impact Report
Engineering News-Record Construction Cost Index
East Palo Alto Sanitary District
Enhanced Watershed Management Plans
full-time equivalent
DWR
EIR
ENR CCI
EPASD
EWMPs
FTE
GA Groundwater Assessment
Granular Activated Carbon
gallon(s)
GAC
gal
GPC
gpm
groundwater production change
gallons per minute
GSI Green Stormwater Infrastructure
Groundwater Use Assessment
Groundwater Management Plan
High Efficiency Toilet
GUA
GWMP
HET
IPR indirect potable reuse
CITY OF PALO ALTOONE WATER PLAN ix
OCTOBER 2024 / FINAL / CAROLLO
ISG Individual Supply Guarantee
lineal footLF
LRP Landscape Rebate Program
Micro FiltrationMF
MFR
MG
Multi-Family Residential
million gallons
mgd million gallons per day
MOU
NEPA
NOAA
NPR
Memorandum of Understanding
National Environmental Policy Act
National Oceanic and Atmospheric Administration
Non-Potable Reuse
O&M
OWP
PA
Operations and Maintenance
One Water Plan
Palo Alto
PAWS
RCP
Protection and Augmentation of Water Supplies
Representative Concentration Pathways
Regional Housing Needs Assessment
Reverse Osmosis
RHNA
RO
ROC
RWQCP
RWS
RWSP
S/CAP
sf
Reverse Osmosis Concentrate
Regional Water Quality Control Plant
Regional Water System
Recycled Water Strategic Plan
Sustainability and Climate Action Plan
square foot (feet)
SFPUC
SFR
San Francisco Public Utility Commission
Single Family Residential
SFWD
SGMA
SSRF
SWRCB
TDS
San Francisco Water Department
Sustainable Groundwater Management Act
Small Salt Removal Facility
State Water Resources Control Board
Total Dissolved Solids
TM Technical Memorandum
USBR
UV
United States Bureau of Reclamation
ultraviolet
UWMP
WCIP
WET
WIRP
Urban Water Management Plan
Water Conservation Implementation Plan
Water Efficient Technology
Water integrated Resources Plan
CITY OF PALO ALTOONE WATER PLAN x
OCTOBER 2024 / FINAL / CAROLLO
WSA
WSAP
WSCP
$/af
Water Supply Agreement
Water Shortage Allocation Plan
Water Shortage Contingency Plan
dollar per acre-foot
$M million dollars
CITY OF PALO ALTOONE WATER PLAN xi
EXECUTIVE SUMMARY
OCTOBER 2024 / FINAL / CAROLLO
EXECUTIVE SUMMARY
“One Water" is an integrated approach to water management that views all forms of water – imported
water, groundwater, wastewater, stormwater, water conservation and efficiency and more - as
interconnected resources. A One Water Plan enhances resilience against climate change and supports a
communities’ economic, social, and environmental goals. Specifically, the City of Palo Alto (City) One
Water Plan (OWP) provides an initial analysis of water supply and conservation alternatives. It provides a
framework within which the City Council can make decisions now and in the future about which direction
the City wants to proceed with respect to its water supply and conservation portfolio, including which
types of projects the City may want to explore further.
ES.1 Plan Purpose
The specific purpose of the OWP for the City is to present a 20-year, adaptable roadmap of prioritized
alternatives, aggregated into water supply portfolios, that establish a vision and achievable path toward
meeting the City’s water supply and water conservation goals. The OWP presents water supply and water
conservation alternatives for the City that, if implemented, may mitigate the impact of future water supply
uncertainties such as severe multi-year drought, changes in climate, water demand, and regulations. The
key work products of the OWP effort are:
.This One Water Plan which compares potential water supply and water conservation portfolios given
the City’s weighted evaluation criteria; and
.An Excel-based tool that can be used to evaluate and prioritize water supply and water conservation
portfolios now and as future uncertainties are resolved.
These work products together serve as an adaptable roadmap for the City's water strategy to provide
long-term water supply resilience, reliability, and security. By accepting an adaptable OWP with flexible
planning tools, Palo Alto can utilize the tools now and, in the future, to adjust its overall water supply
strategy to meet the City’s needs under changing future conditions.
ES.2 Study Area and Planning Horizon
Palo Alto is located in Santa Clara County on the San Francisco Peninsula, about 15 miles north of San
Jose and 35 miles south of San Francisco. The City provides water, wastewater, recycled water and
stormwater service to nearly 70,000 residents and businesses located within the 26 square miles service
area. The study area for this project is limited to the Palo Alto city limits.
ES.3 Stakeholder Engagement
The OWP was developed to meet the near- and long-term needs of the Palo Alto community. The City
made extensive efforts to engage multiple City departments, regional partners, and the community in
developing this OWP. The regional partners included Bay Area Water Supply & Conservation Agency
(BAWSCA), City of East Palo Alto, City of Los Altos, City of Mountain View, San Francisco Public Utilities
Commission (SFPUC), Stanford University, and Valley Water. The stakeholder engagement materials used
at the various meetings are included in Appendix F.
CITY OF PALO ALTOONE WATER PLAN ES-1
EXECUTIVE SUMMARY
OCTOBER 2024 / FINAL / CAROLLO
ES.4 Water Demand Forecast
This OWP uses three demand scenarios from the BAWSCA Regional Water Demand and Conservation
Projections Update (Maddaus, 2022). These demand projections are characterized as the low, medium,
and high forecasts in the OWP. Table ES.1 summarizes the demand from year 2020 and the three
forecasts through 2045, while a more detailed description can be found in Chapter 2. Notably, even the
high forecast remains more than 4,000 acre-feet per year (afy) below the historic high of 16,900 afy in
1996. This is important because the City has been able to meet all its water demands in the past with
San Francisco Regional Water System (RWS) supplies, while demand was higher in the period 1990-2015
than all three forecasts.
Table ES.1 Total Water Demand Projections through 2045
Demand Projection by Planning Year(1)OWP
Demand
Scenario 2020(2)
(afy))
2025
(afy)
2030
(afy)
2035
(afy)
2040
(afy)
2045
(afy)
Low(3)
Medium(4)
High(5)
11,237
11,237
11,237
11,438
11,650
11,663
11,044
11,762
11,778
10,818
11,874
12,039
10,664
12,210
12,390
10,582
12,546
12,808
Notes:
1) Demand projections include Potable, Non-Potable, and Non-Revenue Water
2) 2020 demand reflects total water use projected in the 2020 UWMP (Palo Alto, 2021).
3) Based on the BAWSCA Regional Water Update – Scenario E (Maddaus, 2022).
4) Based on the BAWSCA Regional Water Update – Baseline with Active and Passive Conservation (Maddaus, 2022).
5) Based on the BAWSCA Regional Water Update – Scenario A (Maddaus, 2022).
ES.5 Existing Water Supplies
Since 1962, except for some very short periods, Palo Alto has solely relied on imported water from the San
Francisco Public Utilities Commission (SFPUC) for its potable water supply needs. The City receives water
from the RWS via five turnouts and primarily collaborates with BAWSCA to oversee its water supply
contract with San Francisco and to engage with the SFPUC.
In addition to the City’s potable water supplied by the RWS, the City has used non-potable recycled water
from the City’s Regional Water Quality Control Plant’s (RWQCP) regional recycled water system since it
began operation in 1980. The first phase of this system serves the Palo Alto Golf Course, Greer Park, the
Duck Pond, and the RWQCP. Palo Alto currently uses recycled water to serve irrigation demand to a
variety of golf courses and City parks.
Palo Alto also owns five deep aquifer groundwater wells that are currently only used during emergencies.
Two of these wells were in operation for approximately six weeks in 1991 when the City faced a severe
45% imported water reduction requirement from SFPUC. Since then, apart from routine annual testing,
these wells have remained inactive.
Table 1.2 lists the historical (year 2020) and projected utilization of the City’s existing water supply sources
during typical years. As shown, the City currently plans to continue to primarily rely on water from the San
Francisco RWS, with non-potable recycled water making up less than 3 percent of the City’s total supply.
CITY OF PALO ALTOONE WATER PLAN ES-2
EXECUTIVE SUMMARY
OCTOBER 2024 / FINAL / CAROLLO
Table ES.2 Historical and Planned Water Supply Sources through 2045
2020
(afy)
2025
(afy)
2030
(afy)
2035
(afy)
2040
(afy)
2045
(afy)Water Supply Sources
RWS Supply
Recycled Water
Total
10,921
316
11,287
316
11,394
316
11,546
316
11,801
316
12,113
316
11,237 11,603 11,710 11,862 12,117 12,429
Notes:
(1) Supply Source Capacities reflect normal year conditions.
(2) Source: 2020 Urban Water Management Plan (UWMP) (Palo Alto, 2021)
ES.6 Potential Water Conservation and Supply Options
This OWP uses a multi-step process to evaluate water supply and conservation options (“options”) and
portfolios. The options evaluation process is graphically depicted in Error! Reference source not found..
As shown, these four steps are
1. Pre-screening of 27 options narrowed down to 15 options
2. Screening of 15 options narrowed down to 9 options
3. Option Evaluation of 9 options to inform composition of 7 portfolios
4. Portfolio Evaluation of 7 portfolios to develop a trigger-based implementation strategy
As shown in in Figure ES.1, the prescreening and screening steps are described in Chapter 3, while the
option and portfolios evaluations are described in Chapter 4 and 5, respectively. This OWP is concluded
with a trigger-based implementation roadmap, which is presented in Chapter 6.
Figure ES.1 Option Evaluation Process
ES.6.1 Options Screening
During the first step, a total of 27 options were compiled using previous studies, new ideas from City staff
and the consultant team, as well as input from stakeholders during public engagement meetings. Table
ES.3 lists the results of the high-level prescreening process that removed 12 of the 27 options because the
options were either 1) already ongoing or planned or 2) not considered feasible at this time.
CITY OF PALO ALTOONE WATER PLAN ES-3
EXECUTIVE SUMMARY
OCTOBER 2024 / FINAL / CAROLLO
Table ES.3 Pre-screening Results of 27 Initial Options
Options that are Options considered not Options selected to be
Ongoing/Already Planned(1)Feasible at this Time(1)
IPR, Lake Lagunita Recharge
Blackwater Capture and Reuse
Valley Water Treated Water
Interagency Transfer Agreement
Tuolumne River Purchases
Atmospheric Water Generators
Local Storage
included in the Screening Process
.Ongoing/Planned Water
Conservation Efforts
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
RWS Supply
Enhanced Conservation, Phase 1
Enhanced Conservation, Phase 2
Groundwater
.
.
Advanced Metering Program
Distribution System Water
Loss Reduction New Irrigation Wells
DPR with Palo Alto Facility
DPR with Palo Alto Facility and SSRF
DPR with Regional FacilityTemporary Dewatering Sites
Permanent Dewatering Sites Palo Alto IPR with Groundwater
Injection
.
.
.
.
.
.
NPR Phase 3 Extension to Foothills
Graywater Capture and Reuse
Residential Rainwater Capture
Green Stormwater Infrastructure
Multi-Source Storage
Bay Water Desalination
Notes:
DPR = Direct Potable Reuse; IPR = Indirect Potable Reuse; NPR = Non-Potable Reuse; RWS = Regional Water System;
SSRF = Small Salt Removal Facility.
1)The options removed from the pre-screening process are described in Appendix B.
The 15 remaining options after the pre-screening were subjected to the screening process using the
following three criteria:
.
.
.
Unit Cost,
Estimated Yield
Supply Reliability
Chapter 3 includes the descriptions, yield estimates, and high-level cost estimates that were prepared for
each of the 15 remaining options. The information used to apply the screening criteria, and the scoring
results are summarized in Table ES.4.
As shown in Table ES.4Error! Reference source not found., the top 8 ranked new local options,
excluding the existing RWS Supply, are:
.
.
.
.
.
.
.
Enhanced Conservation - Phase 1 (score 8)
Enhanced Conservation - Phase 2 (score 8)
Direct Potable Reuse (DPR) with Palo Alto Facility (score 8)
DPR with Regional Facility (score 7)
Indirect Potable Reuse (IPR) with Groundwater Injection (score 7)
Bay Water Desalination (score 7)
Groundwater (score 6)
CITY OF PALO ALTOONE WATER PLAN ES-4
EXECUTIVE SUMMARY
OCTOBER 2024 / FINAL / CAROLLO
.DPR with Regional Facility and Small Saltwater Removal Facility (SSRF) (score 6)
Table ES.4 Options Comparison
Unit Cost
in 2023
dollars(1)
($/af)
Estimated
Yield
in 2045(2)
(afy)
Increases Supply
Reliability in
Drought Years?
Move to
Portfolio
Evaluation
Category Option
Imported Water
Conservation
RWS Supply $2,210
$312
12,546
724
Neutral
Yes
Yes
Yes
Yes
Yes
No
Enhanced Conservation - Phase 1
Enhanced Conservation - Phase 2
Groundwater
$1,939
$4,663
$3,107
$3,594
$8,897
$4,024
$4,992
$9,685
$8,215
$58,321
$16,847
$39,679
$6,768
618 Yes
Groundwater
Water Reuse
2,250
54
Neutral
Neutral
Yes
New Irrigation Wells
DPR with Palo Alto Facility
DPR with Palo Alto Facility and SSRF
DPR with Regional Facility
IPR with Groundwater Injection
NPR with Phase 3 Expansion
Graywater Capture and Reuse
Residential Rainwater Capture
Green Stormwater Infrastructure
Multi-Source Storage
4,723
630
Yes
Yes
Yes
Yes
No
Yes
1,769
5,150
1,100
10
Yes
Yes
Neutral
Neutral
No
Onsite Water
Capture/Reuse
No
1 No
Stormwater
Storage
30 No No
39 Yes No
Desalination Bay Water Desalination 4,480 Yes Yes
Notes:
1) Cost numbers are not rounded from the calculations presented in Appendix C to avoid inconsistencies in rounded values. However, these
are Class 5 planning level (aka “order of magnitude”) cost estimates with a typical estimating accuracy of -50% to +100% due to limited level
of project information often coupled with significant uncertainties at this planning stage.
2) Yields listed reflect normal year conditions only. Some options are subject to a dry year yield reduction as listed in Table 5.1.
It should be noted that 4 of these 8 options are dependent on whether Valley Water decides to exercise
the option that obligates the cities of Palo Alto and Mountain View to transfer a minimum effluent flow
delivery of an annual average of 9 mgd from the RWQCP to Valley Water.
Valley Water has until the end of 2032 to decide whether to exercise the Effluent Transfer Option. Valley
Water may elect to develop a Regional Purification facility to purify the water and use it for beneficial use
in Santa Clara County south of Mountain View. Hence, the two DPR options with the Regional Facility
(with and without the SSFR) can only be implemented with the Valley Water transfer in place. Similarly, the
Palo Alto DPR and IPR options are only possible if Valley Water does not exercise the transfer option as
that would maintain sufficient wastewater effluent flows for Palo Alto to build its own Advanced
Treatment Plant for either IPR or DPR purposes.
ES.6.2 Options Evaluation
The criteria used to evaluate the options in this OWP were developed to reflect a wide range of
perspectives. This includes input from City staff and the community via polling and discussion during the
first two rounds of stakeholder engagement meetings, as described in Chapter 1. The four (4) main
evaluation criteria build upon the screening criteria described in Chapter 3 and include:
1. Reliability
CITY OF PALO ALTOONE WATER PLAN ES-5
EXECUTIVE SUMMARY
OCTOBER 2024 / FINAL / CAROLLO
2. Unit Cost
3. Environmental Benefits
4. Ease of Implementation
The Environmental Benefits and Ease of Implementation criteria each have multiple sub-criteria described
in more detail below. The three Environmental Benefits sub-criteria are 1) Reduced Reliance on the
Tuolumne River, 2) Efficient Use of Water and 3) Ecological Benefits. The Ease of Implementation
sub-criteria are 1) Implementation Timeline, 2) Operational Complexity, and 3) Public Acceptance. The
four evaluation criteria, along with their respective sub-criteria, and the methods used for scoring the
options are described in detail in Chapter 4.
To account for the relative importance or priority to different criteria when making decisions, each of the
(sub)criteria was given a weight based on feedback received from City staff and community members via a
polling at in-person workshop as well as the results of an online survey. The weighting factors used in this
OWP are summarized in Table ES.5.
Table ES.5 Evaluation Criteria Weighting
Evaluation Criteria
Reliability
Unit Cost
Sub-Criteria (Sub)Criteria Weight(1)Combined Weight1)
n/a
n/a
35%
20%
10%
35%
20%
30%Environmental Benefits Reduced Reliance on the Tuolumne
River
Efficient Use of Water
Ecological Benefits
10%
10%
5%Ease of Implementation Implementation Timeline
Operational Complexity
15%
5%
Public Acceptance
(1) Notes:
5%
(2) A sensitivity analysis was conducted to determine if, and how much the portfolio evaluation results would change if the
criteria were weighted differently (higher or lower). The findings are discussed in Section 5.6.
Table ES.6 summarizes the results on the option evaluation. As shown, the following new options score
the highest in order of decreasing score:
.
.
.
DPR with Palo Alto Facility (total score: 3.7)
IPR with Groundwater Injection (total score: 3.6)
Enhanced Water Conservation – Phase 1 and Bay Water Desalination (both total score: 3.2)
It can be concluded that both Enhanced Water Conservation – Phase 1 and IPR with Groundwater
Injection score in the top 3 options, with and without the use of the relative weighting factors. This means
that these options are robust solutions as these are not very sensitive to changes in the weighting factor
percentages as these options score each well in multiple criteria. Both Enhanced Conservation Options
(Phase 1 and Phase 2) were therefore included in all portfolios except for the Baseline Portfolio, which
represents the “Do Nothing” aka “Business as-usual” scenario. Moreover, it can be concluded that the DPR
with Palo Alto Facility and SSRF option scores the lowest with and without weighting factors. This option
was therefore not moved forward to the Portfolio Evaluation.
CITY OF PALO ALTOONE WATER PLAN ES-6
EXECUTIVE SUMMARY
OCTOBER 2024 / FINAL / CAROLLO
Table ES.6 Option Evaluation Results Summary
Environmental Benefits
Reduced
Tuolumne Efficient
River Use of Ecological Implementation Operational
Reliability Cost Reliance Water
Ease of Implementation
Total
Unweighted
Score4
Total
Weighted
Score4,5
Unit Public
Option
Criteria Weight
Benefit Timeline Complexity Acceptance
35%
1.0
1.6
1.5
2.6
4.9
2.5
1.5
5.0
4.9
20%
4.1
5.0
4.0
2.0
3.4
2.9
1.0
2.4
2.0
10%
1.0
1.6
1.5
2.7
4.7
2.4
1.5
5.0
4.5
10%
2
10%
2
5%
5
5%
5
5%
5
n/a n/a
2.4
3.2
2.8
2.5
3.7
2.7
1.7
3.6
3.2
RWS Supply 25.1
28.2
24.0
21.3
22.9
21.7
14.0
24.4
20.4
Enhanced Conservation - Phase 1
Enhanced Conservation - Phase 2
Groundwater
5 4 3 4 4
5 4 2 3 3
2 3 3 3 3
DPR with Palo Alto Facility1
DPR with Regional Facility2
DPR with Palo Alto Facility and SSRF
IPR with Groundwater Injection1
Bay Water Desalination
4 2 1 1 2
4 2 1 5 2
4 2 1 1 2
3 2 2 2 3
3 1 1 1 3
Notes:
(1) DPR with Palo Alto Facility and IPR with Groundwater Injection options assume that Valley Water does not exercise its option to transfer a portion of RWQCP effluent
(selected “No” in the Evaluation Tool)
(2) The DPR with Regional Facility option assumes that Valley Water exercises its option to transfer a portion of RWQCP effluent (selected “Yes” in the Evaluation Tool)
(3) Quantitative criteria scores (Reliability, Unit Costs, Reliance on Tuolumne River) are shown with two significant figures as these are calculated values, while qualitative criteria
scores are scored using whole integers.
(4) The three highest scores of new options (excluding the benchmark RWS Supply) are shown in bold font.
CITY OF PALO ALTOONE WATER PLAN ES-7
EXECUTIVE SUMMARY
OCTOBER 2024 / FINAL / CAROLLO
ES.7 Portfolio Evaluation
As part of this OWP, a total of seven portfolios (A through G) were of developed and evaluated based on
the four following evaluation criteria:
.
.
.
Environmental Benefit is scored for three sub-criteria including Reduced Reliance on the Tuolumne
River, Efficient Use of Water and Ecological Benefits.
Unit Cost is scored based on the projected unit cost expressed in dollar per acre-foot ($/af) of each
portfolio using the capacity weighted unit cost of all options in the respective portfolio.
Reliability is scored based on results of the dry year supply analysis for each portfolio using the
supply gap expressed in afy during a 50 percent reduction in water deliveries to Palo Alto from the
RWS.
.Ease of Implementation is scored based on three sub-criteria: Implementation Timeline, Operational
Complexity, and Public Acceptance.
Table ES.7 summarizes the options included in each portfolio.
Table ES.7 Overview of Options included in each Portfolio
Enhanced
Conservation
Phase 1 and
Phase 2
DPR
with
Alto Regional
Palo
Alto
DPR
Palo
RWS
Supply
X
Bay Water
Desalination
Ground-
waterPortfolio IPR Facility
A. Baseline
B. Enhanced Conservation Phase 1 and 2 X
X
X
XC. Enhanced Conservation Phase 1 and 2
with Bay Water Desalination X
D. Enhanced Conservation Phase 1 and 2
with Groundwater
E. Enhanced Conservation Phase 1 and 2
with Palo Alto DPR
F. Enhanced Conservation Phase 1 and 2
with Palo Alto IPR
G. Enhanced Conservation Phase 1 and 2
with Regional DPR
X
X
X
X
X
X
X
X
X
X
X
X
As shown in Table ES.7, Portfolios A – D can be implemented independent of the decision of Valley Water
to exercise its option to transfer a portion of the treated effluent from the RWQCP. However, Portfolios E
and F may only be implemented if Valley Water does not exercise the effluent transfer option, while
Portfolio G may only be implemented with the transfer option and if Valley Water constructs a DPR
facility.
ES.7.1 Evaluation Tool
The Evaluation Tool was developed to test the performance of different combinations of potential water
supply and conservation options across a range of supply, conservation, and demand scenarios. The
Supply Evaluation Tool was used to evaluate the seven portfolios (A through G). Unless noted differently,
the results presented in this OWP are based on the medium demand scenario (see Table ES.1) and a RWS
Supply reduction of 50%, combined with the implementation of Shortage Stage II, which mandates up to
20% water use reductions per the City’s Water Shortage Contingency Plan (Palo Alto, 2021).
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For ease of comparison, these assumptions are kept constant in the portfolio evaluations described in the
following subsections. However, each of these key assumptions can be modified in the Evaluation Tool
based changing conditions. In addition, the sensitivity of many of these key assumptions are analyzed and
discussed separately in Section 5.6.
The Tool is a key deliverable of this OWP and is intended to also be used to evaluate new portfolios that
may be developed and considered in the future. Appendix D provides a more detailed description of the
Tool and its functionalities.
ES.7.2 Demand and Supply Balance by Portfolio
Figure ES.2 provides a graphical summary from the Tool output that compares Palo Alto’s year 2045 water
supply yields and demands of the seven portfolios side-by-side for normal year conditions.
Figure ES.2 Normal Year Supply and Demand Analysis by Portfolio for 2045
As shown in Figure ES.2, the amount of RWS Supply varies considerably between the portfolios, ranging
from 100 percent of the forecasted demand in 2045 of 12,546 afy (medium growth scenario) in Portfolio A
to as low as 6,053 afy or 48 percent of the total demand in Portfolio F. There is no unplanned supply
shortfall for any of the portfolios under normal year supply and demand conditions.
Figure ES.3 shows the supply and demand balance under extreme water shortage conditions with an
assumed 50 percent cutback of RWS Supply and 20 percent water use reduction (drought reduction) via
water use restrictions and short-term conservation. This is a scenario the SFPUC has said is possible if the
State-adopted Bay Delta Plan unimpaired flow requirements are implemented. Under these conditions,
the City would activate the appropriate stage of its Water Shortage Contingency Plan, presumably
achieving higher than a 20% water use reduction. The unplanned supply gap shown in Figure ES.3 is
illustrative only.
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OCTOBER 2024 / FINAL / CAROLLO
Figure ES.3 Dry Year Supply and Demand Analysis by Portfolio for 2045 with a 50% RWS Supply Cutback
ES.7.3 Portfolio Evaluation Results
Table ES.8 summarizes the weighted portfolio scores, yield, and unit cost by portfolio in both 2023 and
2045 dollars. As shown, four (4) of the seven (7) portfolios are not sensitive to the decision of Valley Water
to exercise the option to transfer effluent. If Valley Water would exercise the transfer option, there would
be sufficient flows to the RWQCP to implement DPR with Regional Facility option included in Portfolio G.
However, if this option is not exercised, Palo Alto would retain sufficient wastewater effluent to implement
either the Palo Alto DPR or Palo Alto IPR options included in Portfolios E and F, respectively.
It can be concluded that Portfolio E (Enhanced Conservation Phase 1 and 2 with Palo Alto DPR) has the
highest score if Valley Water does not exercise the effluent transfer option, while Portfolio G (Enhanced
Conservation Phase 1 and 2 with Regional DPR) has the highest score if Valley Water does exercise the
effluent transfer option. Hence, the combination of enhanced conservation and DPR is the most attractive
path forward to further strengthen Palo Alto’s supply reliability. The type of DPR (Palo Alto or Regional
Facility) is dependent on Valley Water’s decision of exercising the transfer option.
Additionally, the implementation of Enhanced Conservation Phase 1 and 2 without any other large new
water supply project, as defined in Portfolio B, is considered a no-regret option because it is independent
of Valley Water Transfer option decision and consistent with the high individual option scoring results.
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Table ES.8 Portfolio Evaluation Summary
Portfolio Names
Valley Water
Transfer Option
Exercised
Weighted
Portfolio
Score(1)
Yield (afy)Unit Supply Cost ($/af)
Normal
year
Dry
year
2023 2045
dollars dollars
A. Baseline not sensitive
not sensitive
2.55
2.92
0(2)0(2)$2,210
$2,075
$4,088
$3,903B. Enhanced Conservation Phase 1 and 2 1,342 1,342
C. Enhanced Conservation Phase 1 and 2
with Bay Water Desalination
D. Enhanced Conservation Phase 1 and 2
with Groundwater
E. Enhanced Conservation Phase 1 and 2
with Palo Alto DPR
F. Enhanced Conservation Phase 1 and 2
with Palo Alto IPR
not sensitive
not sensitive
only without
only without
only with
2.91
2.79
3.43
2.99
3.06
5,823
3,592
6,065
6,492
3,111
5,823
3,143
5,829
5,978
3,023
$3,854
$2,556
$2,645
$3,323
$2,355
$6,663
$5,330
$4,938
$6,440
$4,552G. Enhanced Conservation Phase 1 and 2
with Regional DPR
1) The weighted portfolio score in the Evaluation Tool is based on the portfolio weighted unit costs in 2045 dollars. The highest scoring portfolios with and without
the Valley Water transfer are listed in bold.2) The Baseline Portfolio solely relies on imported water from the SFPUC via its RWS system, combined with already-planned water conservation programs that
are not included in the Enhanced Conservation measures as described in Chapter 3.
ES.8 Trigger Based Implementation Roadmap
The major triggers that were identified for this OWP that could impact the decision on moving forward
with one of more of the options are:
1. Need to Increase Supply Reliability
2. Valley Water Transfer Option
It should be noted that funding is not included as a trigger because sufficient funding is a common
requirement for all projects. Although insufficient funding can certainly postpone, downsize, or eliminate
projects, it was decided that funding should be considered as an implementation challenge rather than a
trigger. Also important is public acceptance of IPR, DPR and Bay Water Desalination. Palo Alto plans to
work collaboratively and actively with both SFPUC and BAWSCA to incorporate messages and information
about DPR and/or Desalination into outreach materials.
The trigger-based implementation roadmap shown in Figure ES.4 was developed to guide the City of Palo
Alto with prioritization and the decision-making processes for future option implementation. No action or
decision is being recommended at this time regarding the implementation of any of these options. The
purpose of identifying these options is to increase local supply reliability in the event of a prolonged
outage or reduction in imported water deliveries from the RWS. Should one of these conditions arise, the
options can be further evaluated as needed.
As shown in Figure ES.4, the trigger-based implementation roadmap follows a pathway, indicated by the
blue arrows pointing to the trigger decisions that are shown as orange diamonds. Each trigger is a key
decision point that leads to different pathways depending on the answer to the trigger question with
either a YES or NO. Note that in reality, the answers are not binary, and some grey areas will exist.
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EXECUTIVE SUMMARY
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Figure ES.4 Trigger-Based Implementation Roadmap
ES.9 Next Steps
The OWP recommends the following actions to enhance the City’s water supply reliability that reflect the
priorities of the City, as well as the input received from regional partners and the community during the
stakeholder engagement process utilities for the development of this Plan:
1. Start with the planning and exploration of the Enhanced Water Conservation measures included in
Phase 1 including but not limited to the following:
.
.
.
.
.
Outdoor Irrigation Efficiency for Commercial, Industrial, or Institutional (CII) Properties
3-Day Watering Week
Non-Functional Turf Ban for CII Properties
Lawn Limitation for New Development and Major Retrofits
Low Income Residential High Efficiency Toilet (HET) Replacement Program
2. Once the Enhanced Conservation Phase 1 program activities are set in motion, start with the planning
and exploration of the Enhanced Conservation Phase 2 measures, namely:
.
.
.
Lawn Limitation for Residential Properties upon Resale
HET Replacement Program for CII Properties
City Landscaping Support for Turf Replacement
3. Incorporate education and monitoring of the level of support for IPR, DPR, and/or Bay Water
Desalination in City’s community engagement activities in close collaboration with regional agencies.
4. Update the option cost estimates, and Excel-based Evaluation Tool assumptions as new information
becomes available and periodically update the trigger-based roadmap implementation plan.
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5. Prepare a conceptual feasibility study for the DPR, IPR, Bay Water Desalination and/or Groundwater
Treatment option(s) once there is more clarity on which of these larger supply options may be
implemented in the future (if any).
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CITY OF PALO ALTOONE WATER PLAN ES-14
CHAPTER 1
OCTOBER 2024 / FINAL / CAROLLO
CHAPTER 1 INTRODUCTION
This chapter introduces the Palo Alto One Water Plan (OWP or Plan), including the purpose of One Water
planning, the project background, and key drivers for the preparation of the OWP. Furthermore, this
chapter outlines previous planning initiatives, followed by a description of the OWP study area and
planning timeline. Lastly, the chapter explains stakeholder engagement process and how input was used
to guide the plan development and concludes with a list of acknowledgements and an overview of the
Plan organization.
1.1 Plan Purpose
“One Water" is an integrated approach to water management that views all forms of water – imported
water, groundwater, wastewater, stormwater, water conservation and efficiency and more - as
interconnected resources. A One Water Plan enhances resilience against climate change and supports a
communities’ economic, social, and environmental goals. Specifically, the City of Palo Alto (City or Palo
Alto) OWP provides an initial analysis of water supply and conservation alternatives. It provides a
framework within which the City Council can make decisions now and in the future about which direction
the City wants to proceed with respect to its water supply and conservation portfolio, including which
types of projects the City may want to explore further.
The specific purpose of the OWP for the City is to present a 20-year, adaptable roadmap of prioritized
alternatives, aggregated into water supply portfolios, which establish a vision and achievable path toward
meeting the City’s water supply and water conservation goals. The OWP presents water supply and water
conservation alternatives for the City that, if implemented, may mitigate the impact of future water supply
uncertainties such as severe multi-year drought, changes in climate, water demand, and regulations. The
key work products of the OWP effort are:
.This One Water Plan which compares potential water supply and water conservation portfolios given
the City’s weighted evaluation criteria.
.An Excel-based tool that can be used to evaluate and prioritize water supply and water conservation
portfolios now and as future uncertainties are resolved.
These work products together serve as an adaptable roadmap for the City's water strategy to provide
long-term water supply resilience, reliability, and security. By accepting an adaptable OWP with flexible
planning tools, Palo Alto can utilize the tools now and, in the future, to adjust its overall water supply
strategy to meet the City’s needs under changing future conditions.
1.2 Motivations for Development of a One Water Plan
The City has several motivating factors for developing this OWP including:
.Providing water reliability for community needs (such as drinking water, tree canopy health, recreation
and habitat needs) during droughts and considering the impacts of climate change.
Providing adequate water supply to meet the City’s projected increases in water demand.
Including community input and support in the City's water planning efforts.
.
.
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Future water supply reliability may be affected by recent regulations. In 2018, the State Water Resources
Control Board (SWRCB) adopted amendments to the Water Quality Control Plan for the San Francisco
Bay/Sacramento-San Joaquin Delta Estuary also known as the “Bay-Delta Plan Amendments,” to establish
water quality objectives to maintain the health of the Bay-Delta ecosystem (SWRCB, 2018). The Bay-Delta
Plan Amendments require the release of 30-50 percent of the unimpaired flow on the three San Joaquin
River tributaries (the Stanislaus, Merced, and Tuolumne Rivers) from February through June. Unimpaired
flow represents the natural water production of a river basin, unaltered by upstream diversions, storage,
or by export or import of water to or from other watersheds. (SWRCB 2018, p. 17, footnote 14). If the
Bay-Delta Plan is implemented, the San Francisco Public Utilities Commission (SFPUC) expects to be able
to meet Wholesale Customers projected water demands in normal years but would experience supply
shortages and require rationing in single dry years or multiple dry years (SFPUC, 2021). The SFPUC has
initiated an Alternative Water Supply Planning program to meet its Retail and Wholesale Customer water
needs, address projected dry year shortages, and limit rationing to a maximum 20 percent system-wide in
accordance with adopted SFPUC policies.
In August 2018, the Palo Alto City Council voted to support the Bay-Delta Plan Amendments and sent a
letter expressing the policy position to the Bay Area Water Supply and Conservation Agency (BAWSCA),
California State Water Resources Control Board, and SFPUC (Palo Alto, 2018d). Consistent with the
Council’s policy position in support for the Bay-Delta Plan, the OWP explores alternatives that reduce
reliance on the San Francisco Hetch Hetchy Regional Water System (“San Francisco RWS” or “RWS”). A key
driver of the OWP is to study the feasibility of implementing alternative water supply sources to reduce
reliance on the RWS and to increase water supply reliability for Palo Alto.
The SFPUC operates the RWS, which Palo Alto is 100 percent dependent on for drinking water. Given the
City’s forecasted water demand as well as projections of water supply availability provided by the SFPUC,
the City anticipates the need to implement water use reductions in the range of 35 - 55 percent during
droughts after the implementation of the Bay-Delta Plan Amendment. The State is taking steps toward
implementation of the Bay Delta Plan Amendments including preparing a draft Environmental Impact
Report (EIR) and regulations to implement the updates the State adopted in 2018.
Moreover, the RWS crosses seismically active faults, and the water supply is subject to potential supply
interruption in the event of earthquake damage. SFPUC’s Water System Improvement Program (a multi-
year capital program to upgrade the RWS) greatly reduced the system’s seismic vulnerability. Palo Alto is
addressing the intermittent use of groundwater during an emergency such as an earthquake as part of
the City’s capital budgeting process.
In contrast, the OWP focuses on new permanent water sources such as the use of groundwater in all years
to reduce Palo Alto’s reliance on the RWS and increase reliability by developing alternative water supply
sources.
.There are also several factors not included in the OWP that Palo Alto is addressing as part of other
planning efforts, including:
.
.
.
Catastrophic loss of supply due to earthquakes or other events.
Use of groundwater blending during droughts.
Green building requirements.
The OWP is not focused on development of city policies regarding expanded green building requirements
although findings may lead to refinement of green building policies, requirements or mandates.
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1.3 Key Previous Planning Efforts
The OWP builds on previous water supply studies, plans, and efforts by the City including the following
key documents:
.Long Term Water Supply Study (2000): This study was prepared for the City by Carollo Engineers,
Inc. in 2000 (Carollo, 2000). This is the earliest-referenced study used in this OWP that is geared
towards understanding how Palo Alto could meet water supply deficits should there be a cutback in
water supply from SFPUC. Supply alternatives investigated include emergency groundwater well
conversion, utilizing groundwater for irrigation, connecting to the Valley Water system, and
participating in a new water supply project with the California Water Service Company. This study was
specifically used for the groundwater supply options considered in this OWP.
.BAWSCA Long-Term Reliable Water Supply Strategy (2015): BAWSCA is a special district created
by the California legislature in 2003 to represent the interests of Palo Alto as well as 23 other cities
and water districts and two private utilities that purchase water on a wholesale basis from San
Francisco. BAWSCA developed the 2015 Long-Term Reliable Water Supply Strategy (“2015 Strategy”)
(CDM Smith, 2015) which assessed the water supply reliability requirements of BAWSCA member
agencies until 2040. It identified potential water supply management projects or programs to address
these needs and devised an implementation plan for executing the Strategy's recommendations.
BAWSCA is initiating an update to the 2015 Strategy called Strategy 2050.
.2017 Water Integrated Resources Plan: The City completed the third iteration of the Water
Integrated Resources Plan (WIRP) in 2017 to update prior versions prepared in 1993 and 2003. The
2017 WIRP (Palo Alto, 2017) includes an evaluation of potable water supplies available to Palo Alto
including SFPUC water, groundwater, treated water from Valley Water, as well as demand
management strategies. Evaluation criteria included normal and dry year availability, water quality,
cost, emergency robustness, sustainability, and regulation sensitivity. This OWP includes and updates
some of the water supply and water conservation options from the 2017 WIRP.
.Northwest County Recycled Water Strategic Plan (2019): The City prepared the Northwest County
Recycled Water Strategic Plan (RWSP) in 2019 (W&C, 2019). This plan included a recycled water
demand assessment and prepared several concept options for non-potable reuse (NPR), indirect
potable reuse (IPR), and direct potable reuse (DPR). Selected recycled water concepts from the RWSP
were used as the basis for developing the reuse options in this OWP. The RWSP also included the
following key technical memoranda (TMs) used to inform this OWP:
»
»
»
Groundwater Assessment and Indirect Potable Reuse Feasibility Evaluation and
Implementation Strategy: Characterization of the underlying groundwater basin and evaluation
of IPR project feasibility. This study was used to inform the groundwater and IPR options in the
OWP.
TM for Task 6.3 – Using Groundwater from Temporary Dewatering Systems for Irrigation:
Evaluation of using groundwater from permanent and temporary dewatering sites within the City
as an irrigation source. Assumptions made in this TM were used to inform groundwater
dewatering water supply options within Palo Alto.
TM for Task 6.4 – Using Groundwater to Irrigate City Parks: Evaluation of conversion of the
City’s emergency supply wells for irrigation compared with installing new irrigation wells at City
parks. This TM was used to inform assumptions for groundwater supply options in the OWP.
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.
.
.
TM for Task 6.5 – Increasing Flow to RWQCP by Redirecting Existing Permanent Dewatering
System to Sewers: Evaluation of using permanent dewatering water as an additional water source for
a future recycled water project. This TM was used to inform assumptions for adding permanent
dewatering flows to the water reuse projects evaluated in this OWP.
Green Stormwater Infrastructure Plan (2019): The City’s Green Stormwater Infrastructure (GSI) Plan
was prepared in 2018 (Palo Alto, 2019a). This Plan includes discussions of the long-term plan for
integrating GSI within the City landscape and stormwater systems. The GSI Plan guided the
development of the GSI option in the OWP.
Partnership Agreement to Advance Resilience Water Reuse Programs in Santa Clara County
(2019): In 2019, the City of Palo Alto, City of Mountain View, and Valley Water reached an agreement
to advance collective water reuse in Santa Clara County (Valley Water, 2019). This agreement commits
an annual average of 9 mgd (i.e., approximately half) of the treated wastewater from the Regional
Water Quality Control Plant (RWQCP) to Valley Water for use. In return, Valley Water will financially
contribute to the construction of a small salt removal facility to produce higher quality recycled water
for use by Mountain View and Palo Alto. This agreement was used to inform the flow assumptions for
the different forms of potable reuse projects evaluated as a part of the OWP.
.
.
Palo Alto 2020 Urban Water Management Plan: The City prepared and adopted its 2020 Urban
Water Management Plan (UWMP) in June 2021 (Palo Alto, 2021). This is a state-mandated assessment
of City’s water supply and demand, including current water conservation efforts and water shortage
contingency plan. It should be noted that the demand projections presented in the 2020 UWMP differ
from the demands used in this OWP, as explained in more detail in Chapter 2.
Sustainability and Climate Action Plan (2023): The City’s Sustainability and Climate Action Plan
(S/CAP) was completed in 2023 (Palo Alto, 2023b). The S/CAP includes two water-specific goals:
1. Reduce Palo Alto’s potable water consumption by 30 percent compared to a 1990 baseline
(subject to refinement based on forthcoming California water efficiency standards expected in
2024).
2. Develop a water supply portfolio which is resilient to droughts, changes in climate, and water
demand and regulations, which supports the City’s urban canopy.
These goals are supported by the following four key actions:
1. Maximize cost-effective water conservation and efficiency through incentives,
outreach/education, and other programs.
2. Design and build a salt removal facility for the Regional Water Quality Control Plant to
improve the quality of recycled water.
3. Develop and implement projects that result from a "One Water" Portfolio of alternative water
supply and water conservation options (“Options”) for Palo Alto, including but not limited to:
stormwater, recycled water, on-site reuse, conservation, groundwater.
4. Develop a tool for dynamic water planning in the future.
The last two key actions, the development of a One Water Portfolio and a dynamic water planning tool,
are satisfied in this OWP. The conservation options considered in this OWP also contribute to planning for
the first key action of maximizing cost-effective water conservation and efficiency.
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1.4 Geographical Study Area
Palo Alto is located in Santa Clara County on the San Francisco Peninsula, about 15 miles north of San
Jose and 35 miles south of San Francisco. Palo Alto is located along the San Francisco Bay at an average
elevation of approximately 30 feet above sea level. As of 2020, Palo Alto is home to approximately
69,000 residents (Palo Alto, 2022a). The City service area is approximately 26 square miles and is depicted
in Figure 1.1. The study area for this project is limited to the Palo Alto city limits.
1.5 Planning Period
This OWP serves as a guiding document for the planning and implementation of water supply
improvements and water conservation options to accommodate future water supply needs through the
next 20 years. For planning purposes and to provide consistency with the planning horizon of the
upcoming 2025 UWMP, the 20-year planning period was extended through the year 2045.
Planning uncertainties increase further into the future projections are made due to an increasing margin of
error in forecasting future conditions. Despite these uncertainties, the City finds it important to prepare the
projections in the OWP given the importance of ensuring adequate water supplies and the potentially long
timeframe for implementation of different water supply alternatives. The Excel tool prepared as a part of
this OWP will allow the City to update the findings regularly to adjust for changes in "existing" conditions,
incorporate new data and science, address evolving regulations, and/or extend the planning horizon.
1.6 Stakeholder Engagement
The OWP was developed to meet the near- and long-term needs of the Palo Alto community. The City
made extensive efforts to engage stakeholders and the public in developing a plan that reflects a breadth
of local technical expertise and the community's values and priorities through a multi-phase stakeholder
engagement process. Primary elements of stakeholder engagement in support of OWP analyses included:
.
.
Community, City, and regional partner engagement meetings.
Live polling throughout the engagement meetings to collect live feedback (this included the use of an
online live polling website called Mentimeter).
.
.
.
Email-based survey distributed to community members.
Maintaining an OWP email distribution list to provide updates.
Maintaining a dedicated OWP website posting updates and past engagement meeting materials.
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Figure 1.1 Palo Alto City Limits
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The following subsections describe the key elements of the community, City, and regional partner
engagement activities to support the development of this OWP. The key stakeholder engagement
materials used during the OWP planning process are included in Appendix F.
1.6.1 Community Engagement
The City advertised community engagement meetings through email lists, City websites, social media,
business associations, and on bulletin boards at City facilities. All community meetings were conducted in
a hybrid format where attendees could either attend in person or via Zoom. After each meeting, the City
posted the meeting slides, recording, and live polling results, as applicable, on the dedicated OWP
website. The following three meetings were held for community members:
.
.
.
Community Meeting #1, Community Needs and Priorities: The first meeting was conducted at City
Hall on September 28, 2022. The purpose of this meeting was to provide community members with
an introduction to what an OWP is and what the City’s goals and priorities are in developing this plan
as well as an overview of the City’s existing water supplies. This meeting included a live Mentimeter
polling activity assessing the public’s feedback to Palo Alto’s current and future water supply.
Community Meeting #2, Exploring Water Supply and Water Conservation Options: This meeting
was conducted on December 7, 2022, and provided an overview of possible water supply and water
conservation options to be considered in the OWP and the evaluation criteria for these options. The
meeting included a live Mentimeter polling activity allowing participants to rank the proposed
evaluation criteria.
Community Meeting #3, Sharing the Initial Results: This meeting was conducted on June 3, 2024,
at the Utilities Advisory Commission regular meeting.
1.6.2 City Departments
The following City departments were engaged in three virtual (via Zoom) stakeholder meetings
throughout OWP process:
.
.
.
.
.
.
Administrative Services Division.
City Manager’s Office.
Community Services.
Planning & Community Environment – Code Enforcement.
Planning & Development Services.
Public Works, including the divisions of Development Center, Environmental Control, RWQCP, Urban
Forestry, Watershed Protection.
.Utilities, including the divisions of Customer Service, Engineering & Operations, and Resource
Management.
Similar to the community engagement meetings, three engagement meetings were held throughout the
OWP development covering the same series of topics:
.City Department Meeting #1, Community Needs and Priorities: This meeting was conducted on
September 26, 2022 and included the same content and polling activity as the equivalent community
meeting. Additionally, the City department meeting featured an open discussion section on
multi-benefit capital improvement projects (CIP) that could be integrated into the OWP.
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.
.
City Department Meeting #2, Exploring Water Supply and Water Conservation Options: This
meeting was conducted on December 5, 2022, and included the same content and polling activity as
the equivalent community meeting.
City Department Meeting #3, Sharing the Initial Results: This meeting will occur once the One
Water Plan is available for participants to review.
1.6.3 Regional Partners
Many regional partners were engaged in two virtual (via Zoom) stakeholder meetings throughout the
OWP process and incidental follow-up conversations. The regional entities, in alphabetical order are:
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Bay Area Water Supply & Conservation Agency (BAWSCA).
City of East Palo Alto (BAWSCA member and RWQCP partner).
City of Los Altos (RWQCP partner).
City of Mountain View (BAWSCA member and RWQCP partner).
San Francisco Public Utilities Commission (SFPUC).
Stanford University (BAWSCA member and RWQCP partner).
Valley Water.
The City held two regional partner engagement meetings covering the following topics:
.Regional Partner Meeting #1, Exploring Water Supply and Water Conservation Options: This
meeting was conducted on December 6, 2022. Provided a brief introduction to what an OWP is and
what the City’s goals and priorities are in developing this plan. Provided an overview of potential
water supply and water conservation options and evaluation criteria being considered in the OWP,
with a focus on options that included regional collaboration. Included a collaborative discussion to
assess if there were further regional supply/collaboration ideas or if any presented ideas would
adversely impact a regional partner.
.Regional Partner Meeting #2, Sharing the Initial Results: This meeting will be held once the One
Water Plan is available for participants to review.
1.7 Report Organization
This report is organized in 6 chapters. A brief description of the information presented in each of the
remaining chapters is included below.
Chapter 2 – Water Demands and Supplies: This chapter describes the City’s historical, existing, and
future water demands drawing on historical data from BAWSCA demand studies, the 2020 UWMP, and
future projections. The chapter also provides a historical overview of the City’s existing water supplies.
Furthermore, it details the various existing water supply sources, such as SFPUC water, recycled water,
groundwater, and the water conservation programs, essential for meeting the region's water needs.
Chapter 3 – Potential Water Supply & Water Conservation Options: This chapter focuses on the City’s
potential water supply and water conservation options (“Options”). It begins with a discussion on
methodology, detailing the pre-screening and screening processes. The chapter then outlines various
supply and conservation options, including groundwater utilization, water reuse (both recycled and
purified), stormwater management, on-site customer reuse (such as graywater and rain barrels), storage
solutions, desalination, and conservation measures.
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Chapter 4 – Options Evaluation: This chapter describes the evaluation criteria used to compare and
narrow down the options described in Chapter 3. The chapter then discusses criteria weighing before
evaluating various options, such as SFPUC, enhanced conservation phases, groundwater, potable reuse
(both IPR and DPR), and Bay water desalination, among others. The chapter concludes with the selected
options that move forward to the long-term water supply portfolio analysis described in Chapter 5.
Chapter 5 – Portfolio Evaluation: This chapter describes the portfolio evaluation. It outlines the
approach and assumptions used for the evaluation process and describes the portfolios analyzed grouped
into options whether or not Valley Water exercises its option to transfer a portion of treated effluent from
the RWQCP. The chapter describes the customized Evaluation Tool developed for this OWP and portfolio
analysis task, summarizes the portfolio evaluation results, and the results of a sensitivity analysis of the
evaluation criteria weighting and other key planning assumptions. The chapter concludes with a summary
of the portfolio evaluation outcomes and implementation considerations.
Chapter 6 –Recommended Implementation Plan: This chapter provides a trigger-based
implementation roadmap which is presented to guide the City with decision-making as conditions
continue to evolve in the future. This chapter concludes with the next steps.
1.8 Acknowledgements
We would like to thank the following City staff for their assistance and oversight of this project:
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Karla Dailey– Assistant Director of Utilities Resource Management.
Karin North – Assistant Director of Public Works.
Matt Zucca – Assistant Director of Utilities Water-Gas-Wastewater Engineering and Operations.
Lisa Bilir – Senior Resource Planner.
Pam Boyle Rodriguez - Stormwater Compliance Program Manager.
Samantha Engelage – Senior Engineer.
Linda Grand – Water Conservation Program Manager.
Rebecca Oliver – Associate Resource Planner (former employee).
Silvia Santos – Engineering Manager Water-Gas-Wastewater.
Elise Sbarbori – Manager of Environmental Control Programs.
Natalie Semersky – Water Resource Planning Intern.
The following Carollo team members were principally involved in this project:
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Anne Prudhel, PE – Principal-in-Charge.
Inge Wiersema, PE – Project Manager.
Rachel Duncan, PE – Ass. Project Manager and Project Engineer.
Warren Greco, PE – Evaluation Tool.
Madison Rasmus, PE – Lead Planner (former employee).
Riya Jadhav, EIT – Staff Engineer.
Matthew Huang, PE – Cost Estimating.
Kevin Christensen – GIS Specialist and Mapping.
Jacquelin Reed, MBA – Stakeholder Engagement (former employee).
John Rehring, PE – Technical Advisor & Quality Review Lead.
Jeff Stoval, PE –Technical Advisor Groundwater Options.
Jacques deBra (Luhdorff and Scalmanini Consulting Engineers) – Water Conservation.
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CHAPTER 2 WATER DEMANDS AND SUPPLIES
This chapter starts with a description of the City of Palo Alto’s (City) historical, existing, and projected
future water demands. Next, this chapter provides an overview of the history of the City’s existing water
supplies. Finally, it details the various existing water supply sources, such as San Francisco Regional Water
System (RWS), recycled water, groundwater, and conservation programs, essential for meeting the
region's water needs.
2.1 Current and Projected Demands
The following subsections describe the City’s historical and projected water demands. This analysis is
based on historical and existing water demands, utilizing data from the Bay Area Water Supply and
Conservation Agency (BAWSCA) 2022 demand study and/or the City’s 2020 Urban Water Management
Plan (UWMP). Moreover, this chapter describes future demand projections to gain a comprehensive
insight into water demand dynamics.
2.1.1 Historical and Existing Water Demands
Over the past 30 years, the City’s total water demand has ranged from under 10,000 acre-feet per year
(afy) to 16,900 afy with an average of 13,900 afy. However, in recent years, water use has decreased to an
average of approximately 11,100 afy, which equates to just under 10 million gallons per day (mgd). This
reduction in water use is generally attributed to the profound effect the drought of 2014 to 2016 had on
customer behaviors regarding water use. The City’s total water use from 1990 through 2020 includes
potable water purchased from the San Francisco Public Utility Commission (SFPUC) and recycled water
use. As shown in Figure 2.1, recycled water comprises only a small percentage of the City’s total water
supply, accounting for approximately 5 percent on average between 1990 and 2020.
18,000
16,000
14,000
12,000
10,000
8,000
6,000
4,000
2,000
0
Fiscal Year
Potable Water Recycled Water
Figure 2.1 Palo Alto Historical Water Use (1990-2020)
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The City serves a broad range of customers, with the two largest customer types being single-family
residential (SFR) and multifamily residential (MFR). Figure 2.2 shows the distribution of water demand by
customer type. Together, these two residential sectors make up approximately 63 percent of the City’s
total demand on average. Commercial and landscape customers are the next largest sectors, with
15 percent and 12 percent of total demand, respectively. Institutional, industrial, and government
customers make up the remaining 10 percent of demand.
Government, 3%
Landscape, 12%
Institutional, 4%
Industrial, 3%Single Family
Res percentdential,
46%
Commercial, 15%
Multifamily
Resid percentntial,
17%
Figure 2.2 Distribution of Water Use by Customer Type (2020 Data)
2.1.2 Future Demand Projections
The BAWSCA Regional Water Demand and Conservation Projections Update (Maddaus, 2022) developed
projected water demands for Palo Alto. The demand projections developed by BAWSCA utilize monthly
water production and water consumption from 1995 through 2021, unemployment projections, water
rates, service area demographics, and other inputs. The BAWSCA demand study used the Demand Side
Management Least Cost Planning Decision Support System Model (DSS Model) and an econometric
model to determine short- and long-term demand projections for each BAWSCA member agency,
including Palo Alto, and region-wide. BAWSCA’s demand projections include an updated baseline
scenario and a sensitivity analysis to assess how a range of influences, including population and job
growth, housing density changes, water rate escalations, water conservation, and long-term climate
change impacts the demand projection.
This OWP uses three scenarios for Palo Alto from the updated BAWSCA demand projections and
characterizes the scenarios as low, medium, and high forecasts. A brief description of the three demand
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forecasts is provided below, while more detail can be found in BAWSCA’s Regional Water Demand and
Conservation Projections Update (Maddaus, 2022):
.Low Demand Forecast: This forecast is based on Scenario E from BAWSCA’s updated demand
projections. This scenario assumes slower population and employment growth when compared to the
City’s 2020 UWMP, caused by job automation, job relocation out of the Bay Area, remote work
flexibility, and generational retirement waves, along with high housing prices. This scenario assumes
reduced water use from higher water rates and additional conservation activities that occur in
response to worsening climate conditions. The projected low demand forecast for the year 2045 is
10,582 afy (16 percent lower than the medium forecast).
.
.
Medium Demand Forecast: This forecast is based on BAWSCA’s updated baseline demand
projections. This projection is an updated version of the water projections used in the City’s 2020
UWMP. Population and job projections were based on the City’s 2030 Comprehensive Plan. The
projection also includes assumptions for active and passive conservation savings and continued
recycled water use. The projected medium demand forecast for the year 2045 is 12,546 afy.
High Demand Forecast: This forecast is based on Scenario A from BAWSCA’s updated demand
projections. The water conservation, population, and employment projections are published in the
City’s 2020 UWMP, which includes additional refinements for projected housing units and more
multifamily development. This scenario assumes that there are no severe technological, geopolitical,
or climate disruptions in the Bay Area’s economy and that new residential development remains
consistent with recent trends. The projected high demand forecast for the year 2045 is 12,808 afy
(2 percent higher than the medium forecast).
Table 2.1 lists the demand projections used in the OWP and Figure 2.3 graphically depicts the demand
projections.
Table 2.1 Total Water Demand Projections through 2045
Demand Projection by Planning Year(3)OWP
Demand
Scenario
BAWSCA’s
Regional Demand Update(1)
Scenario Name 2020(2)
(afy))
2025
(afy)
2030
(afy)
2035
(afy)
2040
(afy)
2045
(afy)
Low Scenario E 11,237 11,438
11,650
11,663
11,044
11,762
11,778
10,818
11,874
12,039
10,664
12,210
12,390
10,582
12,546
12,808
Medium Baseline with Active & Passive Conservation 11,237
Scenario A 11,237High
Notes:
1) BAWSCA Regional Water Demand and Conservation Projections Update (Maddaus, 2022).
2) 2020 demand reflects total water use projected in the 2020 UWMP (Palo Alto, 2021).
3) Demand projections include Potable, Non-Potable, and Non-Revenue Water.
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Figure 2.3 Water Demand Projections Through 2045
As shown in Figure 2.3, the medium and high demand scenarios follow a similar trajectory, increasing
from the 2020 demand of 11,237 afy to over 12,500 afy by 2045. The low demand scenario projects a
decrease over the same period, with approximately 10,600 afy by 2045. Hence, the range in the demand
forecast for the year 2045 is about 2,200 afy, which equates to an 18 percent deviation compared to the
medium forecast. These demands reflect total water use, including retail sales of potable water,
non-revenue water, and recycled water. Notably, even the high forecast remains more than 4,000 afy
below the historic high of 16,900 afy in 1996. This is important because the City has been able to meet all
its water demands in the past with RWS supplies, while demands were higher in the period 1990-2015
than all three forecasts.
2.2 Water Supply History
The City established the water utility in 1896, shortly after the City's incorporation, and originally used
shallow groundwater wells to provide water to residents of the then 750-person community. As the City
grew, the groundwater well system expanded, eventually reaching nine (9) wells in operation by 1932. The
San Francisco Public Utility Commission (SFPUC) was established in 1932 and the Hetch Hetchy water
system was completed in 1932. From 938 until 1962, Palo Alto purchased increasing amounts of water
from the SFPUC to supplement water available from local wells. In the 1950s, groundwater production
also increased, leading to lower groundwater tables and water quality concerns. In 1962, Palo Alto
changed its supply source to 100 percent SPFUC water to provide softer water for consumers. In 1984,
Palo Alto signed a 20-year contract with the SFPUC and kept the City's groundwater wells for standby and
emergency water sources. Since 1962, except for some short periods, Palo Alto has solely relied on
imported water from the SFPUC for its potable water supply needs. The City receives water from the RWS
via five turnouts and primarily collaborates with BAWSCA to oversee its water supply contract with San
Francisco and to engage with the SFPUC.
In addition to the City’s potable water supplied by the RWS, the City has used non-potable recycled water
from the City’s Regional Water Quality Control Plant’s (RWQCP) regional recycled water system since it
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began operation in 1980. The first phase of this system serves the Palo Alto Golf Course, Greer Park, the
Duck Pond, and the RWQCP. The City completed Phase Two of the regional recycled water system in
2009, which replaced a deteriorating pipeline to the Shoreline Golf Course in the City of Mountain View
and extended the pipeline to the Mountain View-Moffett area.
2.3 Existing Water Supply Sources
Table 2.2 lists the existing and proposed water supply sources for the City during typical years, as stated in
the City’s 2020 UWMP (Palo Alto, 2021). As shown, the City currently plans to continue to primarily rely on
water from the San Francisco RWS, with non-potable recycled water making up less than 3 percent of the
City’s total supply capacity.
Table 2.2 Historical and Planned Water Supply Sources through 2045
2020
(afy)
2025
(afy)
2030
(afy)
2035
(afy)
2040
(afy)
2045
(afy)Water Supply Sources
RWS Supply
Recycled Water
Total
10,921
316
11,287
316
11,394
316
11,546
316
11,801
316
12,113
316
11,237 11,603 11,710 11,862 12,117 12,429
Notes:
Supply Source Capacities reflect normal year conditions.
Source: 2020 UWMP (Palo Alto, 2021).
2.3.1 San Francisco RWS Supply
San Francisco Regional Water System
Around 85 percent of the San Francisco RWS water supply originates from the Tuolumne River in the
Sierra Nevada, transported via the Hetch Hetchy aqueducts, while the remaining 15 percent is treated
water sourced from local watersheds and facilities in Alameda and San Mateo Counties. The availability of
RWS imported water is limited by various factors, including hydrology, physical infrastructure, and
institutional regulations governing the allocation of water from the Tuolumne River. Consequently, the
RWS relies heavily on reservoir storage to provide a consistent water supply, particularly during dry years.
Water Supply Agreement
In July 2009, the SFPUC and its Wholesale Customers entered into the Water Supply Agreement (WSA),
incorporating a Water Shortage Allocation Plan (WSAP) to allocate water from the RWS to both Retail and
Wholesale Customers during system-wide shortages of 20 percent or less. The method for allocating
water between Retail and Wholesale Customers as a whole is known as the “Tier One Plan.” The WSAP
also implements a method for allocating water among the individual Wholesale Customers, which has
been adopted by the Wholesale Customers (including Palo Alto); this method is known as the “Tier Two
Plan.”
Tier One Plan Drought Allocations
Under the Tier One Plan, the SFPUC administers drought water shortage allocations when it determines
that the projected available water supply is less than the projected system-wide water purchases in the
upcoming year. Table 2.3 shows the allocation of the annual water supply available during shortages
between the SFPUC (Retail Customers) and Wholesale Customers.
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Table 2.3 Tier One Plan Drought Shortage Allocations
Share of Available WaterLevel of System-Wide Reduction SFPUC
Share
Wholesale Customers
Sharein Water Use Required Total
5% or less 35.5%
36.0%
37.0%
37.5%
64.5%
64.0%
63.0%
62.5%
100%
100%
100%
100%
6% through 10%
11% through 15%
16% through 20%
The Tier One Plan is set to expire at the termination of the WSA term in 2034 unless mutually extended by
SFPUC and the Wholesale Customers. The Tier One Plan is applicable only when the SFPUC determines
the existence of a system-wide water shortage and issues a declaration of a water shortage emergency
under California Water Code Section 350. Separately from such an emergency declaration, the SFPUC may
choose to request voluntary reductions in water use from its Retail and Wholesale Customers to achieve
necessary water conservation during periods of drought.
Tier Two Plan Drought Allocations
The Wholesale Customers have collectively negotiated and endorsed the Tier Two Plan, which distributes
the collective Wholesale Customer share allocated by the Tier One Plan among the 26 Wholesale
Customers. The Tier Two Plan allocations are determined by a formula that considers various factors for
each Wholesale Customer, including:
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Individual Supply Guarantee (ISG).
Seasonal utilization of all available water supplies.
Residential per capita usage.
As the characteristics of water usage by Wholesale Customers change over time (such as variations in
RWS purchases, utilization of other water sources, fluctuations in monthly water usage patterns, or
alterations in residential per capita water use), the Allocation Factor for each Wholesale Customer will also
vary.
Initially set to expire in 2018, the Tier Two Plan has been extended annually by the BAWSCA Board of
Directors for an additional calendar year. At the time this OWP was prepared, the Tier Two Plan was set to
expire on December 31, 2024. BAWSCA and the Wholesale Customers are negotiating an update to the
Tier Two Plan that is expected to be completed by the end of 2024.
Drought Allocations During System-Wide Shortages Greater than 20 percent
If RWS shortages exceed 20 percent, San Francisco will:
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Adhere to the allocations outlined in the Tier 1 Shortage Plan up to the 20 percent reduction.
Engage in discussions with Wholesale Customers on how to implement additional reductions beyond
20 percent.
.Make final determinations regarding allocations beyond the 20 percent reduction.
For this OWP, Palo Alto’s cutback percentage is a user-defined input. For the portfolio analysis presented
in Chapter 5, an RWS cutback of 50 percent is used. This assumption is close to the high end of the
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potential supply gap identified by SFPUC in the Alternative Water Supply (AWS) Plan (SFPUC, 2024).
Additionally, results are presented for a less severe cutback of 30 percent.
Individual Supply Guarantee
San Francisco has a perpetual obligation (known as Supply Assurance) to provide 184 mgd to the
24 permanent Wholesale Customers collectively. The Supply Assurance is distributed among the
24 permanent Wholesale Customers through the ISG, representing each Wholesale Customer’s share of
the 184 mgd Supply Assurance. Palo Alto's ISG is 16.575 mgd, equivalent to 18,579 afy.
SFPUC Water Supply Alternative Evaluation Efforts
In 2019, the SFPUC established the AWS Program to evaluate new and diverse water supply options to
improve the RWS’s ability to reliably meet demands through 2045. SFPUC published the AWS Plan in
February 2024, and the AWS Plan includes:
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Identification of the anticipated water supply gap through the 2045 planning horizon.
Description of ongoing efforts to reduce demands and optimize RWS supply availability.
Description of AWS Projects that can augment RWS supply and address the future water supply gap.
Recommendations that will further advance the AWS Program.
In assessing the potential water supply gap, SFPUC evaluated drivers, including the implementation of the
Bay-Delta Plan Amendment, climate change, and demand. The AWS Plan states that “the Bay-Delta Plan
Amendment, if implemented as adopted in 2018, would result in new instream flow requirements that
would reduce projected water availability from the RWS in dry years, as expressed as total system yield,
from 257 mgd to 152 mgd”. For the AWS Plan, SFPUC characterized the future water supply gap “as a
range of 92 mgd to meet 2045 customer demands to 122 mgd to meet obligations”. This maximum gap,
or shortage, ranges from 38 percent of total 2045 demands on the RWS to 45 percent of total existing
and potential obligations. SFPUC’s approach to avoid overbuilding new water supply projects is to “Plan
for Obligations and Build for Demands.”
The AWS Plan then describes the six AWS Projects that SFPUC is currently planning and evaluating to
address the water supply gap, which are estimated to augment supply by 22 to 48 mgd in future dry
years. These include one recycled water project that offsets groundwater pumping, three regional purified
water projects (Direct Potable Reuse or DPR), and two water storage expansion projects. Implementing
these projects would reduce the expected 2045 gap by 24 percent (from 76 percent to 52 percent),
leaving a 44 to 70 mgd gap that would need to be met through rationing or implementation of additional
supply and/or demand management projects. SFPUC and other parties are working with the State of
California on a Voluntary Settlement Agreement and continues to plan based on the current adopted Bay
Delta Plan Amendment. The result of the Voluntary Settlement Agreement process will impact water
availability and SFPUC’s future water supply gap estimates.
Water Supply Reliability
Historically, the RWS has consistently met dry-year demands while limiting rationing to a maximum
20 percent system-wide reduction in water service during extended droughts in any given year. During
the 2015-2017 drought, Governor Brown mandated water use reductions across the state, superseding
the SFPUC Tier 1 and Tier 2 Plans. In November 2021, SFPUC declared a water shortage emergency,
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triggering the implementation of the Tier 1 and Tier 2 Plans for the first time. The drought emergency
declaration remained in effect through April 2023.
Based upon the City’s forecasted water demand presented in the City’s 2020 UWMP and projections of
water supply availability provided by SFPUC at the time, the City anticipates the need to implement water
use reductions of approximately 50 percent from pre-drought usage levels in dry years post Bay-Delta
Plan implementation. Table 30 of the 2020 UWMP shows Palo Alto water use reductions in the first
through fifth year of multi-year drought ranging from 45.5 percent to 53.7 percent (Palo Alto, 2021).
During the 2015-2017 drought, the City reduced water use by 31 percent by restricting landscape
irrigation and implementing other conservation and water shortage measures. While the City’s Water
Shortage Contingency Plan (WSCP) does include actions to achieve water use reductions greater than
50 percent, the City does not have experience in implementing such drastic measures and thus lacks
direct knowledge regarding whether those measures would achieve the target water use reductions. Palo
Alto has six water shortage stages in the Water Shortage Contingency Plan – Stages I through VI are
designed to achieve water savings of up to 10 percent, 20 percent, 30 percent, 40 percent, 50 percent, and
greater than 50 percent.
2.3.2 Recycled Water
Wastewater Collection and Treatment in Palo Alto
The City owns and operates the RWQCP, a wastewater treatment plant serving the East Palo Alto Sanitary
District, Los Altos, Los Altos Hills, Mountain View, Palo Alto, and Stanford University (Partner Agencies).
The RWQCP treats wastewater generated by these communities before being discharged into the Bay.
The RWQCP is classified as an advanced secondary treatment facility and encompasses various treatment
stages, including preliminary treatment involving bar screens and grit removal, primary treatment
involving sedimentation basins, secondary treatment utilizing fixed film reactors, nitrifying-activated
sludge, and clarification, and tertiary treatment involving dual media filters made up of anthracite and
sand, followed by UV disinfection. The facility produces Title 22-quality recycled water by subjecting the
tertiary effluent to further filtration through sand filters at low loading rates and disinfection using sodium
hypochlorite. These treatment processes result in removing approximately 99 percent of ammonia,
organic pollutants, and solid pollutants.
The RWQCP has a permitted average dry weather flow capacity of 39 mgd with a permitted peak wet
weather flow capacity of 80 mgd. Average flows as of 2022 stand at approximately 16 mgd, which equates
to about 18,000 afy.
Palo Alto Recycled Water Production
The RWQCP recycled water facility can produce non-potable recycled water meeting the Title 22
unrestricted use standard, with a capacity of approximately 4.5 mgd (5,000 afy). Presently, annual
production stands at approximately 14 percent of this capacity. During peak summer months, monthly
production reaches around 30 percent of the capacity. Furthermore, during peak hours in summer, the
demand nearly reaches 100 percent of the production capacity, with assistance from storage tanks to
manage short-term reuse supply/demand imbalances while staying within the 4.5 mgd production
capacity.
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Current and Potential Recycled Water Use
Phase 1 of the RWQCP’s regional recycled water transmission system has been operational since 1980,
serving recycled water to various locations, including the Palo Alto Golf Course, Greer Park, Duck Pond,
and the process water needs of the RWQCP itself. In 2009, a project was undertaken to replace an aging
pipeline leading to the Shoreline Golf Course in Mountain View and to extend it to the Mountain View-
Moffett area. This replacement project not only restored the connection to the golf course but also
extended recycled water services to the Shoreline community. Table 2.4 shows total RWQCP recycled
water use. As shown, the Palo Alto Golf Course is the largest recycled water user within Palo Alto, and
more recycled water is used for industrial processes at the RWQCP and in Mountain View than in Palo
Alto.
Table 2.4 Uses of Recycled Water from the RWQCP
Annual Demand(1)
(afy)Recycled Water Use
Landscape Irrigation 42
179
63
Golf Course Irrigation
Other non-potable uses
Palo Alto Recycled Water Subtotal
Mountain View Customers
284
452
736Total Uses of Recycled Water from the RWQCP
Notes:
(1) Source: Palo Alto Monthly Wastewater Flows (Palo Alto, 2023)
The City evaluated the feasibility of expanding its recycled water system, most recently in the 2019
Northwest County Recycled Water Strategic Plan (RWSP) (W&C, 2019). This plan evaluated non-potable
reuse (NPR), indirect potable reuse (IPR), and direct potable reuse (DPR) options.
The Partnership Agreement
The Partnership Agreement with Valley Water and the City of Mountain View, approved by Palo Alto’s
council on November 18, 2019, addresses multiple objectives, including diverting treated wastewater
discharge from the Bay, increasing the use of treated wastewater from the RWQCP, and displacing
potable imported water where appropriate and feasible (Palo Alto 2019c). The governing bodies of Palo
Alto, Mountain View, and Valley Water have established policy goals for long-term sustainability,
including expanding the use of recycled water. RWQCP is a local source of drought-proof, sustainable
water. This agreement aims to promote regional collaboration to advance resilient water reuse programs
in Santa Clara County. The agreement is comprised of three primary components:
1. Valley Water will contribute $16 million towards a small salt removal facility's design and construction
at the RWQCP in Palo Alto, with a total cost estimated at the time of the agreement of around $20
million. This facility aims to enhance the quality of non-potable recycled water utilized in Palo Alto
and Mountain View. The improved water quality will be particularly beneficial for irrigation customers
with salinity-sensitive vegetation and, in the near term, facilitate the connection of approximately 60
new recycled water customers in Mountain View to the distribution system.
2. Roughly half of the treated wastewater generated by the RWQCP (9 mgd) will be transferred to Valley
Water for utilization in Santa Clara County south of Mountain View. Valley Water will provide $1
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million annually, allocated among all the RWQCP Partner Agencies contributing treated effluent to the
transfer.
3. Palo Alto and Mountain View will retain the option in the future to request a new potable or non-
potable water supply from Valley Water if required. Any new water resource provided by Valley Water
will be supplied at cost.
October 16, 2023, Council directed staff to secure financing and solicit bids for construction of Phase 1 of
the small salt removal facility (SSRF). Since the time of the agreement, the total estimated project capital
costs increased to $56 million, and this will be funded by the $16 million from Valley Water, $12.9 million
from a US Bureau of Reclamation grant, and the City of Mountain View agreed to pay for the remaining
approximately $27 million in project costs (Palo Alto, 2023n).
2.3.3 Deep Aquifer Groundwater
The City lies within Santa Clara County, where Valley Water serves as the authorized groundwater
management agency. In line with the Sustainable Groundwater Management Act (SGMA) signed by
Governor Brown in September 2014, Valley Water holds exclusive responsibility for groundwater
management in Santa Clara County. Although the Santa Clara sub-basin, managed by Valley Water, is
designated as a medium priority by the California Department of Water Resources, groundwater basins in
the county are not currently adjudicated or considered to be in overdraft.
The Groundwater Management Plan (GWMP) for the Santa Clara and Llagas Subbasins outlines Valley
Water's sustainability objectives, strategies, programs, and activities. Despite heavy reliance on
groundwater during recent droughts by neighboring communities, overall groundwater levels in Santa
Clara County remain satisfactory, thanks to reduced potable water demand and successful efforts by
Valley Water to prevent overdraft, subsidence, and to maintain water quality. Although the City's
groundwater quality is deemed fair to good, it is less desirable compared to supplies from the RWS,
exhibiting six times higher total dissolved solids (TDS) and hardness. While the City hasn't utilized
groundwater since 1991, it is considered to be an available alternative and is regularly evaluated for
potential use, including in this OWP.
Palo Alto built five groundwater wells during the mid-1950s, and the wells remained operational until
1962. In 1988, Palo Alto utilized these wells to supplement water supplies during mandatory rationing
imposed by the SFPUC. Two of these wells were in operation for approximately six weeks in 1991 when
the City faced a severe 45 percent imported water reduction requirement from SFPUC. Since then, apart
from routine annual testing, these wells have remained inactive.
In April 2010, the California Department of Public Health (CDPH) granted approval for an amendment to
the City's water supply permit, adding the new Library/Community Center Well and the Eleanor Pardee
Park Wells. Subsequently, the State permitted the El Camino Park well in 2014. During the permit process,
all three wells underwent testing for compliance with primary and secondary drinking water quality
standards. While the test results currently indicate adherence to primary and secondary standards, there is
a potential for exceeding secondary standards for manganese, iron, and TDS. However, at present, no
additional treatment is necessary to meet secondary standards, as the wells are designated as standby
sources. In emergency situations, the City can implement emergency chlorination treatment at several well
sites, including the Library/Community, Eleanor Pardee, Hale, Peers, and Rinconada wells. Figure 2.4 shows
the locations of the City’s emergency supply wells.
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Figure 2.4 Emergency Supply Well Locations
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The City has identified these wells as potential emergency supply sources for use during prolonged
droughts. They are permitted and classified by the State as “Standby,” and, can only be utilized for up to
5 consecutive days up to maximum of 15 days per year. Collectively, during a drought, these wells may
supply up to 1,500 afy. This standby emergency use must not include blending with RWS water and is
intended for emergency situations where the RWS supply is interrupted.
The pumping limitations imposed on the well system serve as mitigation measures outlined in the
Environmental Impact Report (EIR) prepared for the Emergency Water Supply and Storage Project (Palo
Alto, 2006). Any adjustment to the current restrictions may necessitate a new or supplementary
environmental review. The process for altering the existing limitations will require supporting data
regarding the sustainable yield of the groundwater basin to demonstrate that increased pumping by the
City will not result in significant environmental impacts.
Intermittent use of groundwater in Palo Alto during droughts or other short-term emergencies is
addressed separately as part of the capital budgeting process. The OWP addresses the use of wells for
supplying water during normal and dry years. This would necessitate coordination with the Division of
Drinking Water (DDW) to determine that appropriate treatment measures are in place to meet regulatory
standards. Furthermore, several other considerations must be addressed before employing the wells as a
water supply source for normal and dry years, including the capital expenses associated with any
necessary treatment or blending upgrades, assessing water quality in comparison to RWS water supply,
and evaluating customer acceptance.
While groundwater may offer some advantages for the City in the long term and could prove useful
during water scarcity events, incorporating potable groundwater into the water supply portfolio does not
offer advantages during potable water reductions mandated by the State Water Resources Control Board
(SWRCB) as implemented in 2015 during the severe state-wide drought. According to those regulations,
the City was required to reduce potable water consumption by 24 percent regardless of the water source.
Similarly, Valley Water also requests reductions in groundwater pumping during dry periods.
In 2018, as part of the RWSP, the City completed a Groundwater Assessment (GA) in collaboration with
Valley Water, which involved the development of a comprehensive model of both shallow and deep
aquifers, with a particular focus on identifying potential recharge zones and understanding the
connectivity between these aquifers. The findings of this study indicate that Palo Alto could sustainably
depend on groundwater at a rate of approximately 3,000 afy, equivalent to about 25 percent of the
projected potable water demands for the year 2040. Additionally, the RWSP utilized the results of this
assessment to assess the feasibility of IPR in terms of potential negative impacts related to aquifers.
Moreover, the City could use the findings of the GA to demonstrate sustainable yield for conducting
supplementary environmental reviews. The GA did identify data gaps and recommended conducting
pumping tests with observation wells to better define aquifer parameters (Todd Groundwater, 2018,
section 6.2.2). The findings of the GA have been incorporated into the groundwater and IPR options
included in this OWP.
Shallow Aquifer Groundwater
The Ground Use Assessment (GUA) included in-depth research on shallow and deep aquifers, yielding
valuable insights into their relationship in the northwest region of Santa Clara County. The study revealed
that in areas closer to the bay, a confining layer exists, effectively separating the deep and shallow
aquifers. However, in areas westward toward the foothills, the two aquifers demonstrate connectivity.
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Basement construction frequently occurs in non-residential, mixed-use, and multifamily residential
buildings, particularly those incorporating underground parking. The City's high property and housing
values have led to an increased number of residential property owners seeking to expand their
single-family homes by constructing basements. Groundwater pumping during basement construction
typically occurs in areas with shallow groundwater, often in neighborhoods nearer to the Bay or close to
current or former creek beds. Dewatering continues until a sufficient portion of the structure is built to
stabilize the basement, usually lasting around 10 weeks. Long-term pumping is sometimes required to
address seepage from older underground structures, such as the Caltrain underpass on the Oregon
Expressway.
Temporary groundwater dewatering conducted from July 2019 to August 2020 resulted in the extraction
of over 461 acre-feet. Discharged into the City's storm drain system, groundwater from dewatering
activities enters one of four creeks that eventually flow into the Bay. However, most dewatering sites
discharge into channelized creeks, offering minimal opportunities for groundwater recharge. San
Francisquito Creek stands out as the only creek within the City's boundaries with the potential for
recharging the shallow groundwater basin, as it remains unchanneled.
The City of Palo Alto issues permits for both temporary and long-term (exceeding one year) dewatering
activities. Concerns regarding basement construction groundwater pumping in Palo Alto have escalated
due to the drought and resulting water usage restrictions. These concerns encompass various issues,
including perceived water waste through discharge into storm drains, potential impacts on groundwater
levels and flow rates, potential repercussions on neighboring properties such as subsidence and structural
damage, and effects on trees and landscaping.
The City has historically regulated multiple aspects of basement groundwater pumping for residential and
commercial sites. Public apprehension regarding dewatering practices prompted the City Council to
approve several enhancements to the dewatering policy, including:
.Mandatory installation of fill stations to facilitate water truck filling or connection of garden hoses for
irrigation purposes.
.Submission of usage plans demonstrating efforts to maximize utilization of pumped water and
minimize storm drain discharges.
.
.
Mandating a geotechnical study to assess potential effects and necessary avoidance measures.
Requirement for Street Work/Dewatering permits, issued only after requirements #1, #2, and #3 are
completed).
In November 2020, a technical memorandum was produced to assess the feasibility of reusing water
extracted during dewatering processes (W&C, 2020a). While the groundwater extracted from basement
dewatering generally meets the required quality standards for irrigation use after treatment in a settling
tank, it only accounts for approximately 12 percent of the irrigation demands in Palo Alto under normal
conditions. However, the study revealed various constraints that limit the widespread reuse of dewatering
water. Notably, the logistical challenges of transporting large volumes of groundwater to irrigation sites
via daily truck trips render it impractical to utilize all extracted groundwater for irrigation purposes. The
study estimated that around 2.8 afy, representing less than 1 percent of the total irrigation requirements
citywide, could be reused for irrigation. However, such reuse would incur significant costs both monetarily
and in terms of greenhouse gas emissions. Utilizing water extracted during the dewatering process was
considered part of this OWP, as detailed in Chapter 3.
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2.4 Conservation Programs
To meet the water conservation and efficiency goals set by state and local regulations, Palo Alto
collaborates with Valley Water and the BAWSCA to provide various conservation programs and resources
to all customers in the City. In June 2023, the City Council adopted the (S/CAP. The S/CAP is a
comprehensive document laying out the City's strategy to achieve ambitious carbon reduction and
sustainability goals. The S/CAP outlines goals for increased energy and water efficiency.
For more than fifteen years, Palo Alto has collaborated with Valley Water to implement water efficiency
initiatives aimed at meeting the City's goals for reducing water consumption. This partnership involves
joint funding from Valley Water and the City to support various conservation programs. These programs
focus on promoting water-saving actions for residential and commercial customers.
These efforts include providing free outdoor water audits and offering rebates for landscape efficiency
and commercial equipment. Examples include turf conversion rebates, irrigation equipment upgrades,
residential laundry-to-landscape graywater systems, and commercial fixtures and equipment. Although
residential rebates for toilets, urinals, and clothes washers are not currently available, they may be
reintroduced in the future.
Palo Alto customers can access water conservation resources through the City's website and Valley
Water's website. The existing programs that the City has already implemented and/or are still ongoing are
listed in Table 2.5. This OWP identifies additional water conservation measures referred to as “enhanced”
water conservation. The OWP groups the enhanced conservation programs in two phases and Chapter 3
describes phase 1 and phase 2 in detail.
Table 2.5 Existing Water Conservation Programs
Targets
Indoor Use Outdoor Use
Targets Key Program
FeatureExisting Water Conservation Programs
Water Wise Outdoor Survey Program
Water Wise Indoor Survey Kit
No Yes
No
Free outdoor audit.
Yes Free guide to help find and fix leaks.
Rebates for efficient irrigation devices, turf
conversion.Landscape Rebate Program No Yes
WaterSmart Home Water Report Program
Water Efficient Technology Rebate Program
Yes
Yes
Yes
No
Water Use Feedback to change behavior.
Target CII Customers.
Large Landscape Survey and Waterfluence
Irrigation Budget Program No
No
Yes
Yes
Free audit for customers >0.5 acre lots.
Landscape Workshops Free workshops on water-wise landscaping.
Water Wise Survey Programs
Valley Water administers the Water Wise Indoor and Outdoor Survey Programs, which assist customers in
reducing water usage in their landscapes and homes.
The indoor survey kit enables customers to conduct independent assessments of their homes for leaks
and provides opportunities to improve efficiency. The program distributes water conservation kits, each of
which includes a detailed guide for evaluating water usage along with a flow rate bag for testing shower
and sink flow rates and dye tablets for detecting toilet leaks. Upon completing the survey, customers can
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request complimentary water conservation items for their homes, such as low-flow faucet aerators,
showerheads, and toilet flappers.
Through the outdoor survey, customers receive a complimentary and thorough consultation from a
trained irrigation professional. This consultation involves evaluating the irrigation system on-site to
identify issues, determining rebate programs for which the customer may qualify, and generating a
personalized report outlining the survey findings. This service is available to single-family and small
multi-family properties (with less than 1/2 acre of landscape area) in Palo Alto equipped with a
functioning irrigation system.
Landscape Rebate Program
In collaboration with Valley Water, the City offers the Landscape Rebate Program (LRP) to residents and
businesses in Palo Alto for transitioning approved high water-consuming landscapes (such as irrigated
turf or functional swimming pools) to low water-consuming landscapes. Additionally, it provides
incentives for retrofitting existing irrigation systems with approved high-efficiency equipment, which
includes rain sensors, efficient nozzles, dedicated landscape meters, drip irrigation, and weather-based
irrigation controllers.
As a component of the LRP, the City collaborates with Valley Water to offer Stormwater Rebates. These
rebates are available for customers interested in installing qualifying rain barrels or cisterns to collect
rainwater from existing downspouts or for those planning to establish rain gardens to capture roof water
runoff.
WaterSmart Home Water Report Program
Starting in November 2022, the City launched the WaterSmart Home Water Report and customer portal.
Through this program, the City distributes monthly Home Water Reports via email or mail to single-family
residences in Palo Alto. These reports compare a household's water consumption to that of other Palo
Alto residents with a similar number of occupants and yard size. The reports aim to promote more water-
conscious behaviors and encourage participation in conservation programs. The program is estimated to
have resulted in water savings of about 2.4 percent for households receiving the reports. In addition to
the Home Water Reports, all residents have access to view their consumption and get personalized
recommendations through the WaterSmart portal.
Water Efficient Technology Rebate Program
In collaboration with Valley Water, the City provides the Water Efficient Technology (WET) Rebate
Program. This initiative allows commercial, industrial, and institutional entities, including schools and
hospitals, to obtain rebates for replacing or upgrading equipment with water-efficient technology, leading
to quantifiable reductions in water usage.
Large Landscape Survey and Waterfluence Irrigation Budget Program
Through Valley Water, the City facilitates a program called “Waterfluence” that offers landscape irrigation
surveys and water budgets tailored for commercial, industrial, institutional, and multi-family complex
customers with large landscapes in Palo Alto. Through the Waterfluence portal, customers can access a
suggested watering budget and personalized recommendations, monitor water usage trends, and request
a free landscape field survey. Through the large landscape survey, irrigation professionals conduct on-site
evaluations to suggest improvements for enhancing system efficiency and applicable rebates. This
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program has been operational since 2012, and presently, it encompasses 226 large landscape sites with
dedicated irrigation meters.
BAWSCA Conservation Programs
The City partners with BAWSCA to offer residential landscape workshops and online resources for
customers. In addition, the City participates in the water loss assistance subscription program. BAWSCA
also provides guidance on best practices to comply with State laws.
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CHAPTER 3 POTENTIAL OPTIONS
The One Water Plan (OWP) uses a multi-step process to evaluate water supply and conservation options
(“options”) and portfolios. This chapter details the screening and selection process for the water supply
and conservation options that were considered in this OWP. Specifically, the prescreening process is
briefly described, following by a discussion of the supply option screening criteria and descriptions of the
options that passed through the pre-screening process and subsequent screening criteria. This chapter is
concluded with a listing of the options that are moved forward for a more extensive option evaluation
(see Chapter 4) and the supply portfolio evaluation (see Chapter 5).
3.1 Evaluation Process Overview
The options evaluation process used in this OWP consisted of four main steps, as graphically depicted in
Figure 3.1. As shown, these steps are
1. Pre-screening of 27 options narrowed down to 15 options.
2. Screening of 15 options narrowed down to nine (9) options.
3. Option Evaluation of nine (9) options to inform the composition of seven (7) portfolios.
4. Portfolio Evaluation of seven (7) portfolios to develop a trigger-based implementation strategy.
This chapter described the first two steps of this process as indicated with the orange box. During the first
step a wide range of supply and conservation options were compiled using previous studies, new ideas
from City staff and the consultant team, as well as input from stakeholders during public engagement
meetings. A total of 27 options were subjected to a high-level pre-screening process that narrowed the
list down to 15 options. Conceptual planning level information was either gathered from existing studies,
updated, or developed to have sufficient information to apply the screening criteria. The 9 options that
passed this screening step were then further developed and subjected to a more comprehensive
evaluation process, which is described in Chapter 4.
Figure 3.1 Option Evaluation Process
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3.2 Pre-Screening
As shown in Figure 3.1, the option development began with 27 options that were grouped into three
pre-screening “buckets” as follows:
.
.
.
Ongoing or already planned options (three).
Options not feasible at this time (nine).
Remaining options that moved forward to the screening process (15).
Table 3.1 lists the grouping of the 27 options. The pre-screening process removed options if they were
either 1) already ongoing or planned or 2) not feasible at this time. The 15 options remaining after this
pre-screening process were subjected to the screening process described in this chapter. The options
removed through this pre-screening process are described in more detail in Appendix B.
Table 3.1 Options Pre-screening Results
Options that are Ongoing/Already
Planned
Options not Feasible at this Time:Options selected to be
included in the Screening Process
.Ongoing/Planned Water
Conservation Efforts.
.
.
.
.
.
.
.
.
.
IPR, Lake Lagunita Recharge.
Blackwater Capture and Reuse.
Valley Water Treated Water.
.
.
.
RWS Supply.
Enhanced Conservation, Phase 1.
Enhanced Conservation, Phase 2..
.
Advanced Metering Program.
Distribution System Water Loss
Reduction.Interagency Transfer Agreement. . Groundwater.
Tuolumne River Purchases.
Atmospheric Water Generators.
Local Storage.
.
.
.
New Irrigation Wells.
DPR with Palo Alto Facility.
DPR with Palo Alto Facility and
SSRF.Temporary Dewatering Sites.
Permanent Dewatering Sites..
.
DPR with Regional Facility.
Palo Alto IPR with Groundwater
Injection.
.
.
.
.
.
.
NPR Phase 3 Extension to Foothills.
Graywater Capture and Reuse.
Residential Rainwater Capture.
Green Stormwater Infrastructure.
Multi-Source Storage.
Bay Water Desalination.
Notes:
DPR = Direct Potable Reuse; IPR = Indirect Potable Reuse; NPR = Non-Potable Reuse; RWS = Regional Water System;
SSRF = Small Salt Removal Facility.
Most of the options presented in this chapter are based on previous studies prepared by the City or other
regional entities. Five new options were developed for this OWP. These five options are Enhanced
Conservation, Phases 1 and 2; Graywater Capture and Reuse; Residential Rainwater Capture; Green
Stormwater Infrastructure; and Multi-Source Storage. Chapter 1 describes the key documents used to
update previously developed options, while Appendix A provides a complete list of project references.
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3.3 Screening Criteria
The screening process applied the following three screening criteria to the 15 options that moved forward
from the pre-screening process:
.
.
.
Unit Cost.
Estimated Yield.
Supply Reliability.
These screening criteria are described in more detail below. Each option was scored numerically for each
screening criterion from 1 (worst) to 3 (best), for a maximum possible total score of 9 points. The options
with the highest scores were carried forward to the evaluation.
3.3.1 Unit Cost
Concept-level capital and operations and maintenance (O&M) costs were developed for each option from
previous studies and/or evaluations for the options where cost information was readily available. If cost
information was not available for an option, conceptual planning level costs were developed for the
option based on other similar projects.
As needed, costs were escalated to present day values using the September 2023 Engineering News-
Record Construction Cost Index (ENR CCI) for San Francisco, the nearest metropolitan area in the ENR CCI.
To normalize costs across options of different sizes, the unit cost was used for a screening criterion. The
unit cost is expressed in dollar per acre-foot ($/af) using the amortized capital cost plus the annual O&M
cost ($/year) divided by the anticipated average annual supply yield (afy). Appendix C provides detailed
cost estimates showing the inputs and assumptions for each option.
Unit costs were scored on a scale from 1 (worst) to 3 (best) based on their cost relative to the City’s
current cost to purchase water from the Regional Water System (RWS), which is approximately $2,200/af
(SFPUC 2023). Scores for the unit cost of the new options are assigned as follows:
.
.
.
3 (best score): < $2,000/af (less than RWS water cost).
2 (medium score): $2,000 to $4,000/af.
1 (worst score): > $4,000/af (approximately double RWS water cost).
3.3.2 Estimated Yield
Yield is the anticipated amount of water a given option can provide to the City per year. As described in
Chapter 2, the City currently purchases its entire potable water demand of approximately 11,000 afy from
the RWS. The Estimated Yield screening criterion evaluates the amount of water supply each option can
offset Palo Alto’s current reliance on RWS Supply. Conservation options achieve this by offsetting demand
and supply options achieve this by increasing local water supplies. Scores for Estimated Yield are assigned
as follows:
.
.
.
3 (best score): > 2,000 afy.
2 (medium score): 100 to 2,000 afy.
1 (worst score): < 100 afy.
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3.3.3 Supply Reliability
The Supply Reliability screening criteria examines if the option will improve reliability in drought
conditions, which is a key driver and objective of the OWP. Scores for the Supply Reliability screening
criteria are assigned as follows:
.
.
.
3 (best score): Yes, the option increases reliability during drought years compared to the baseline
RWS supply.
2 (medium score): Neutral, the option may or may not increase reliability during drought years
compared to the baseline RWS supply.
1 (worst score): No, the option does not increase reliability during drought years compared to the
baseline RWS supply.
3.4 Screening
The following subsections describe each of the 15 options that passed the pre-screening criteria. The
following sections provide a description of each option evaluated in the screening process as well as the
justification for the score in each screening category. Because there is a finite amount of effluent available
from the Regional Water Quality Control Plant (RWQCP), the reuse options are mutually exclusive, except
for the Direct Potable Reuse (DPR) with the Palo Alto Treatment Facility and Small Salt Removal Facility
(SSRF) option that is feasible even if the Valley Water Transfer occurs. The 15 options described on the
following pages, in order of occurrence, are:
1. RWS Supply.
2. Enhanced Conservation, Phase 1.
3. Enhanced Conservation, Phase 2.
4. Groundwater.
5. New Irrigation Wells.
6. DPR with Palo Alto Treatment Facility.
7. DPR with Palo Alto Treatment Facility and SSRF.
8. DPR with Regional Treatment Facility.
9. Palo Alto IPR.
10. NPR Phase 3 Extension to Foothills.
11. Graywater Capture and Reuse.
12. Residential Rainwater Capture.
13. Green Stormwater Infrastructure.
14. Multi-Source Storage.
15. Bay Water Desalination.
The description of each option concludes with a summary of the total screening score. A comparison of
the options that made it through the screening process is included at the end of the chapter in
Section 3.5.
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3.4.1 RWS Supply
Description3.4.1.1
This option reflects the City's current potable supply, which is entirely provided by the RWS.
Approximately 85 percent of this supply is from the Sierra Nevada, delivered through the Hetch Hetchy
aqueducts, and approximately 15 percent is treated water produced by San Francisco from its local
watersheds and facilities in Alameda and San Mateo Counties. A diagram of the RWS system is shown in
Figure 3.2. Palo Alto has five connections to the RWS, which each supply water directly into the City's
water distribution system. More information describing the City’s supply from the RWS can be found in
the "Existing Water Supply Sources” section of Chapter 2.
Source: SFPUC 2020 UWMP
Figure 3.2 San Francisco Hetch Hetchy RWS
3.4.1.2 Costs
Palo Alto’s cost to purchase water from the RWS is a combination of SFPUC’s base rate and a debt service
payment for a debt the BAWSCA agencies owed to SFPUC. In 2013, BAWSCA used bond financing to pay
the debt directly, which lowered the cost of repaying the debt. As Palo Alto currently directly feeds and
pressurizes its distribution system with RWS water using existing connections, there is no capital
infrastructure cost associated with this option for the City. This OWP categorizes the amount paid by Palo
Alto to SFPUC as an O&M cost. A cost estimate summary of the key cost components is shown in
Table 3.9, while a detailed cost estimate for this option can be found in Appendix C. As shown, the
estimated total unit cost in 2023 is $2,210/afy, resulting in a cost score of two (2). Future unit costs
through FY 2032/33 are based on SFPUC’s 10-year financial plan, while costs through 2045 are
extrapolated based on the average historical rate increase since 2013 (4.2 percent per year).
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3.4.1.3 Estimated Yield
Palo Alto's Individual Supply Guarantee (ISG) of 16.575 mgd (18,579 afy) is available in normal years.
While SFPUC manages the RWS with the goal of keeping system-wide drought cutbacks to less than
20 percent, if the Bay-Delta Plan is implemented, SFPUC estimates there may be system-wide shortages of
about 50 percent for Wholesale Customers during multi-year droughts. Hence, the dry year yield is
assumed to be 50 percent of the City's projected demand and used as the "worst-case" dry year yield
scenario for the OWP. Given the RWS large yield, even in dry years, this option gets an estimated yield
score of three (3).
3.4.1.4 Supply Reliability
Palo Alto purchases water from the SFPUC under the terms of the 25-year Water Supply Agreement. The
RWS has provided a highly reliable water supply in the past. Given that RWS supply is the baseline
reliability against which all other supplies are compared, it receives a supply reliability score of two (2).
3.4.1.5 Total Screening Score
Receiving a total screening criteria score of seven (7), the RWS supply option will move forward to the
portfolio evaluation process as described in Section 3.5. It's also important to include this option in
portfolio analysis since the RWS, as the City’s current source of potable water, will continue to be a
significant portion of all water supply portfolios considered by the City and is the benchmark for portfolio
comparison purposes.
3.4.2 Enhanced Water Conservation – Phase 1
3.4.2.1 Description
Water conservation options are any measures that the City can take to facilitate a reduction in water use.
Conservation measures fall into three broad categories: indoor water use reduction, outdoor water use
reduction, and water loss reduction. The City has ongoing and planned conservation programs with the
goal of reducing per capita water use to comply with the statewide regulation for “Making Water
Conservation a California Way of Life” (DWR, 2017) and the City’s Sustainability and Climate Action Plan
(S/CAP) goals. These ongoing conservation measures will proceed regardless of the outcome of this OWP,
so they are referred to herein as “Baseline Conservation.” Enhanced conservation includes conservation
measures that go above and beyond the City’s ongoing and planned baseline conservation program. The
enhanced conservation program would reduce water use by increasing commercial, institutional, and
industrial (CII) irrigation efficiency, instituting a permanent 3-day watering week, banning non-functional
turf at CII properties, limiting residential lawns for new construction and major retrofits, and incentivizing
the use of high efficiency toilets in low-income residences.
Unlike the supply options developed in this Plan, the enhanced conservation options consist of
combinations of multiple measures. Enhanced conservation is evaluated as two separate options that
represent a phased approach of implementing multiple conservation measures (Phase 1 and Phase 2). The
OWP divides the individual conservation measures into two phases generally based on a prioritization of
the most cost-effective measures expressed in dollars per acre-foot of demand reduction ($/af).
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Enhanced Conservation Phase 1 includes measures that are estimated to cost less than $1,000/af and are
generally considered to be easier to implement than existing measures or are measures that the City has
already decided to prioritize in the near term. Enhanced Conservation Phase 2 includes measures that are
more expensive and potentially more difficult to implement. There are eight (8) total enhanced water
conservation measures included in Phase 1 and Phase 2. In addition to the conservation measures
included in Phase 1 and Phase 2, there may be additional or alternative water conservation measures that
the City re-evaluates in the future, such as the measures included in Valley Water’s Model Water Efficient
New Development Ordinance.
For each measure in Phase 1, Table 3.2 includes a brief description as well as the estimated time to
saturation, required city staffing time, yield, and unit cost. These characteristics are defined as follows:
.Time to Saturation: The time to saturation is defined as the estimated number of years it will take
before the program reaches all its intended targets and no further progress can be made. For
example, Measure 2 (Outdoor Irrigation Efficiency for CII Properties) has an estimated time to
saturation of 5 years, indicating that all the targeted customers will have decreased their outdoor
water use five years after the program starts, and there will be no further CII properties participating.
Measures that are not expected to reach saturation levels by 2045 are considered “ongoing.”
.
.
Staffing Time: The estimated city staffing time represents the amount of time that a City staff person
would need to dedicate to the program, expressed in full-time equivalent (FTE).
Estimated Yield: The estimated annual yield for each measure is presented as the number of
acre-feet of water conserved each year once the measure reaches saturation or at the end of the
planning horizon (2045) for ongoing measures. Due to the time it takes to “ramp up” these programs
and reach saturation, the yield gradually increases over time and is thus lower in earlier planning
years.
.Unit Cost: The unit cost for each measure was calculated by dividing the total measure cost from
2025 through 2045 by the estimated total cumulative yield over the same period. As shown, the
estimated unit cost of the various conservation measures ranges from $115/af for Measure 2 to
$4,133/af for Measure 4. Palo Alto partners with Valley Water on many conservation programs and
the costs listed here represent the cost to Palo Alto. Partnerships and cost-sharing with Valley Water
for future programs would need to be worked out collaboratively with Valley Water. Additional
conservation measure partnerships with Valley Water may be able to offset some of these costs.
Detailed information on the estimated yield and cost estimates can be found in Appendix C.
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Table 3.2 Enhanced Conservation - Phase 1 Measures Summary
Water
Conservation
Measure
Name
CityTime to
Saturation
(years)
Unit
Cost(2)
($/af)
Staffing Yield(1)
Time
(FTE)
Measure #Description (afy)
Targets CII buildings that are irrigating above their
budget as calculated by WaterFluence and
provides technical guidance and landscaping
support for customers to decrease water use to
recommended levels. The estimated yield assumes
that all 60 CII customers identified as exceeding
their calculated irrigation need decrease their water
Outdoor
Irrigation2 5 0.6 229 $115Efficiency for used for irrigation to meet the volume calculated for
CII Properties their property by the WaterFluence program.
Although the City already implements this program
as a baseline conservation program, the goal of
this measure is to go above and beyond what City
staff are currently doing by providing more
technical support to the target buildings.
Bans all turf in apartments, churches, commercial
properties, HOAs, and streetscapes. Allows turf in
schools and parks for recreational use. Assumes
that 50% of turf at apartments, churches and
Non-
Functional
HOAs, 90% of turf at commercial properties, and all
streetscape turf is replaced with drought tolerant
3 Turf Ban for landscaping. According to WaterFluence data, this
CII would result in replacing approximately 28 acres of
10 0.4 132 $372
Properties(3) turf in Palo Alto. It is assumed that there may be
additional program costs for a spatial analysis
survey to identify non-functional turf in the City, as
well as costs associated with legal review and
implementation of the turf ban.
This measure would pay for low-income
households to replace existing toilets with High-
Residential
Low-Income to include HET replacements in approximately 200
HET households. It is assumed that two toilets are
Replacement replaced at each house, and the savings per toilet
Efficiency Toilets (HET). This program is assumed
5 10 0.05 11 $2,347
Program replaced are approximately 12.2 ccf/yr (0.028 afy).
The cost of each HET and installation is estimated
to be approximately $875 per toilet.
This measure would ban front lawns in new
residential developments or on major renovations
of existing homes. This ban is assumed to result in
the turf removal and replacement at about 100
residential properties per year with assumed lawns Ongoing
sizes of approximately 600 sf and annual turf
replacement savings of 36 gal/sf (5 af/ac). There
may be additional program costs for legal review
and implementation.
Lawn
Limitation for
New
Development
and Major
Retrofits(3))
6 0.4 139 $981
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Water
Conservation
Measure
Name
CityTime to
Saturation
(years)
Unit
Cost(2)
($/af)
Staffing Yield(1)
Time
(FTE)
Measure #Description (afy)
This measure would limit landscape irrigation to 3
days per week from March to October and to 1 day
per week from November to February. The
estimated yield is a reduction of outdoor water use
by 5%.
3-Day
Watering
Week(4)
8 1 0.2 212 $159
Total 724 $312
Notes:
(1) Yield reflects the average annual volume of water saved in 2045 after measures reach saturation and/or based on water
savings of ongoing measures.
(2) Cost assumptions reflect 2023 dollars.
(3) In October 2023, the State passed AB1572 banning potable water irrigation of non-functional turf for CII properties. The ban
will take effect in phases between 2027 and 2031, with local governments complying by 2027, CII properties complying by
2028, and common areas of HOA complying by 2029. This bill dovetails with this conservation measure and may decrease
some of the staff time required to implement the measure. Note that this measure differs from AB1572 in that it assumes
that CII properties replace turf with drought-tolerant plants, while AB1572 bans the use of potable water and does not
require landscape changes.
(4) The water savings of 212 afy for the 3-day watering week measure are based on the existing outdoor demands, which
results in a unit cost of 159/af. The benefit of this measure could decline over time if other outdoor water conservation
measures are also implemented, which would reduce the yield to 164 afy, equating to a unit cost increase of $177/af by
2024.
The estimated cumulative increase of water savings from the various measures is depicted in Figure 3.3.
Based on discussions with City staff, it was decided to prioritize the more cost-effective and/or
easier-to-implement measures in Phase 1. The Phase 1 measures are generally estimated to cost less than
$1,000/af and are considered relatively easy to implement. However, Measure 5 (Residential Low Income
HET Replacement Program) has also been included in Phase 1 as the City has decided to prioritize this
measure due to considerations other than cost, namely equity and community benefit. The total
anticipated yield in 2045 for these five measures is approximately 724 afy. As shown in Figure 3.3, the
water savings are expected to gradually increase over time with an average savings of 602 afy in the
period 2025-2045.
Figure 3.3 Projected Water Savings from Enhanced Water Conservation – Phase 1
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3.4.2.2 Costs
As shown in Table 3.9, the unit costs for conservation measures included in Enhanced Conservation Phase
1 range from $115/afy for Measure 2 to $2,347/afy for Measure 5. Due to the gradual increase in water
savings, the weighted unit cost of $312/af is based on the average yield of 602 afy in the period 2025 to
2045 rather than the projected yield of 724 afy in 2045. A cost estimate summary of the key cost
components is shown in Table 3.9, while a detailed cost estimate for this option can be found in Appendix
C.
As shown, this option does not include any capital or land acquisition cost. Instead, all costs are
associated with labor and incentives, which are both categorized as O&M Cost. In total, for Phase 1 and
Phase 2 Enhanced Conservation, 3.85 FTE are estimated to be required at an annual cost of $0.6 million in
2023 dollars. The average unit cost across measures, weighted by the yield of each measure, is $312/afy.
This results in a cost score of three (3).
3.4.2.3 Estimated Yield
The fully saturated yields for individual conservation measures included in the Enhanced Conservation
Phase 1 range from 11 afy for Measure 5 to 229 afy for Measure 2. The total yield for implementing all of
these measures is 724 afy in 2045, although potential savings overlaps between Measures 2 and 3 may
result in a slight reduction of this yield. Since the yield is greater than 100 afy and lower than 2,000 afy,
this option receives a yield score of two (2).
3.4.2.4 Supply Reliability
Using less water by enhancing conservation measures supports a drought-proof supply by ensuring that
more water is available for critical needs during periods of drought. Enhanced conservation receives a
reliability score of three (3).
Total Screening Score
Receiving a total screening criteria score of eight (8), this option will move forward to the portfolio
evaluation process as described in Section 3.5.
3.4.3 Enhanced Water Conservation - Phase 2
3.4.3.1 Description
This option would implement the enhanced water conservation measures described in Table 3.3, while the
estimated cumulative increase of water savings from the various measures is depicted in Figure 3.4. The
water conservation measures are listed in Table 3.9, while the estimated cumulative increase of water
savings from the various measures is depicted in Figure 3.4. These measures included in Phase 2 would be
in addition to the measures already included in Enhanced Conservation Phase 1. The total anticipated
yield for these three measures is approximately 618 afy, and the weighted unit cost is $1,939/afy. As
shown in Table 3.3, each measure includes a brief description as well as the estimated time to saturation,
required city staffing time, yield, and unit cost.
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Table 3.3 Enhanced Conservation Phase 2 Measures Summary
Water CityTime to
Saturation
(years)
Unit
Cost4
($/af)
Staffing Yield(1)
Time
(FTE)
Measure # Conservation
Measure Name
Description (afy)
HET replacement rebate program for offices,
schools, hospitals, and any other CII buildings
with documented high indoor uses. This program
is assumed to result in the replacement of
approximately 765 toilets at CII properties. It is
assumed that the savings per toilet replaced are
approximately 12.2 ccf/yr (0.028 afy). The cost of
each HET and installation is estimated to be
approximately $875 per toilet.
HET
Replacement
Program for CII
Properties
1 10 0.3 21 $3,314
This measure would build on the City's existing
turf replacement incentive program, conducted in
partnership with Valley Water, to include
increased technical support for single-family
customers to replace turf with drought-tolerant
landscaping. In addition to the financial turf
City
Landscaping4 Ongoing 0.4 152 $4,133Support for Turf replacement incentive ($2/sf), costs for this
Replacement(2) program include staff time to assist single-family
customers in replacing their turf via landscape
redesign and construction management support
and an additional $2/sf to help cover direct
installation costs.
Requires removal of turf front lawns upon resale
of residential properties. This turf ban is
assumed to result in turf removal and
replacement at about 400 residential properties
Lawn Limitation per year with assumed lawn sizes of
for Residential approximately 600 sf and annual turf7 Ongoing 1.5 445 $1,094Propertiesreplacement savings of 36 gal/sf (5 af/ac). Given
Upon Resale3 the challenges with enforcing this measure, it's
assumed that there is an 80% compliance rate
among the City's customers. There may be
additional program costs for legal review and ban
implementation.
Total 618 $1,939
Notes:
(1) Yield reflects the volume of water saved in 2045 after measures reach saturation and/or based on water savings of ongoing
measures.
(2) Measures 2, 3, and 4 target outdoor irrigation and may have some overlap, leading to a reduction in total expected savings
from those programs if they are all implemented. For example, if CII customers remove all non-functional turf (Measure 3),
savings from increased irrigation efficiency (Measure 4) are likely to decrease.
(3) Similar to Note (2), Measures 6 and 7 target residential front lawns and may overlap, leading to a reduction in total expected
savings if they are both implemented. For example, if a customer first renovates a house and then sells it, there would not
be savings from the sale as the front lawn would have already been removed.
(4) Cost assumptions reflect 2023 dollars.
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Figure 3.4 Projected Water Savings from Enhanced Water Conservation – Phase 2
3.4.3.2 Costs
The unit costs for conservation measures included in Enhanced Conservation Phase 2 range from
$1,094/afy for Measure 7 to $4,133/afy for Measure 4. Due to the gradual increase in water savings, the
weighted unit cost of $1,939/af is based on the average yield of 330 afy in the period 2025 to 2045 rather
than the projected yield of 618 afy in 2045.
Table 3.9 shows a cost estimate summary of the key cost components, and Appendix C provides a
detailed cost estimate for this option. As shown, this option does not include any capital or land
acquisition cost. Instead, all costs are associated with labor and incentives, which the OWP categorizes as
O&M costs. This option receives a cost score of three (3).
3.4.3.3 Estimated Yield
The fully saturated yields for individual conservation measures included in the Enhanced Conservation
Phase 2 range from 21 afy for Measure 1 to 446 afy for Measure 7. The total yield for implementing all
these measures is 618 afy in 2045. Since the yield is between 100 afy and 2,000 afy, this option receives a
yield score of two (2).
3.4.3.4 Supply Reliability
Using less water by enhancing conservation measures supports a drought-proof supply by ensuring that
more water is available for critical needs during periods of drought. However, as customers implement
more water conservation and efficiency measures demand hardens and it will become more difficult to
achieve further water use reductions through conservation and efficiency or through drought water use
restrictions. Enhanced conservation receives a reliability score of three (3).
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3.4.3.5 Total Screening Score
Receiving a total screening criteria score of eight (8), this option will move forward to the portfolio
evaluation process as described in Section 3.5.
3.4.4 Groundwater
3.4.4.1 Description
This option would repurpose two of the City’s existing emergency supply groundwater wells for regular
potable use. These wells can provide the City with groundwater drawn from the Santa Clara Valley
Groundwater Basin, specifically, the San Francisquito cone. The City constructed five groundwater wells in
the 1950s and operated the wells for water supply until 1962. From 2009 to 2013, the City rehabilitated
these five existing wells and constructed three more wells. These wells are a part of the City’s emergency
water supply and can support a minimum of eight hours of normal water use and four hours of fire
suppression (Palo Alto, 2021).
Currently, groundwater can only be disinfected with free chlorine and cannot be mixed with
chloraminated water from the RWS without compromising taste and odor and disinfection properties.
Accordingly, the City’s groundwater wells are only suitable for emergency use to fully replace RWS water
sources and cannot be used concurrently with RWS water supply.
The Utilities Department is planning to address the inability to use emergency supply wells in conjunction
with RWS supply during a drought emergency through proposals in the City’s capital budgeting process
within the next five years. The City plans to install ammonia injection capability to chloraminate the
extracted groundwater and allow mixing with RWS water. These improvements would allow the City to
operate the groundwater wells concurrently with RWS water as future conditions warrant. These
improvements will include making any necessary improvements, including valving and controls, and
adding backup power to two additional wells (in addition to the El Camino well that is currently equipped
with backup power). Additionally, the City plans to seek approval from the State to add two more wells to
active standby status. For the purposes of this OWP, the Groundwater option assumes that this issue has
been mitigated, and this discussion focuses on the regular use of groundwater during dry and normal
years.
All of the City’s groundwater wells are screened in the deep aquifer (screened intervals ranging from 108
to 1,020 feet below ground surface) and produce 600 to 3,300 gallons per minute (gpm). The estimated
capacities of each well are listed in Table 3.4, while the locations of these wells are shown in Figure 3.5.
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Figure 3.5 Existing Emergency Supply Wells
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Table 3.4 Emergency Supply Well Capacities
Estimated Capacity Estimated CapacityWell Current Status(afy)
2,340
5,326
1,130
2,744
1,130
2,986
1,614
968
(gpm)
Hale Creek 1,450
3,300
700
Emergency Use only.
Emergency Use only.
Emergency Use only.
Emergency Use only.
Emergency Use only.
Regular Use permitted.
Emergency Use only.
Emergency Use only.
N/A
Rinconada Park
Fernando
Peers Park 1,700
700Matadero
El Camino Park
Eleanor Pardee Park
Main Library and Garden
1,850
1,000
600
Total 18,238 11,300
Data Sources:
(1) 2017 Water Integrated Resources Plan (Palo Alto, 2017).
(2) Groundwater Assessment and Indirect Potable Reuse Feasibility Evaluation and Implementation Strategy (Todd
Groundwater, 2018).
As shown in Table 3.4, the combined instantaneous flow rate of these eight (8) wells is estimated to be
over 11,000 gpm or 15.8 million gallons per day (mgd), exceeding the entire potable water demand for
the City. However, seven (7) of the eight (8) groundwater wells are currently only permitted to be used for
emergency supply, up to 5 consecutive days for up to 15 days per year. Only the El Camino Well is
permitted for use as an active well, not subject to emergency supply limitations (Palo Alto, 2017).
This option assumes that the El Camino Park and Eleanor Pardee Park wells would be converted such that
the well(s) could be used on a regular basis. To convert the wells to regular use, the groundwater supply
would be treated for iron, manganese, and total dissolved solids (TDS) and appropriately disinfected
before being pumped into the City’s water distribution system. Well permits with the state would need to
be modified to incorporate the treatment and change from standby use.
The 2017 Water Integrated Resources Plan (WIRP) evaluated the feasibility of this well conversion and
concluded that two options were feasible: either fully supply Palo Alto’s potable water with groundwater
that is treated for iron, manganese, and TDS instead of importing RWS Supply, or supply a portion of Palo
Alto’s potable water supply with groundwater and that portion may be treated for iron, manganese and
TDS or blended with RWS Supply (Palo Alto 2017). As shown in Table 3.4, total well pumping capacity if all
the emergency supply wells were used continuously is over 18,000 afy. However, this level of groundwater
use would not be sustainable for the underlying groundwater basin. In 2018, groundwater modeling
completed as a component of the Northwest County Recycled Water Strategic Plan (W&C, 2020b)
estimated the City could pump 3,000 afy of groundwater from the Santa Clara Valley Groundwater Basin
for supply without negative impacts on sustainably managed groundwater levels (Todd Groundwater,
2018). Thus, 3,000 afy was used as the assumed volume of groundwater that may be safely and
sustainably extracted for this option. The yield is 2,250 afy due to assumed losses from treatment. It
should be noted that this yield could be sustainably increased, should an indirect potable reuse (IPR)
project be implemented where more water is supplied to recharge the groundwater basin.
The groundwater modeling conducted by Todd Groundwater also concluded that 2,400 afy could be
pumped solely from the El Camino well without undesirable impacts to the aquifer. To meet the 3,000 afy
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yield, this option assumes that the El Camino well and one additional well (Eleanor Pardee) would be
converted from emergency to active operational status. The 2018 modeling efforts found that the Main
Library and Eleanor Pardee Park wells were not influenced by any contamination plumes at that time and
also produced stable total dissolved solids (TDS) and chloride concentrations. The Matadero and
Fernando wells were eliminated due to close proximity to a contamination plume and the Hale and
Rinconada wells were eliminated because they have seen increasing TDS and chloride concentrations in
recent years (reasons for these TDS and chloride increases were noted as unknown in the 2018 study).
Due to the higher capacity compared with the Main Library Well, the best options identified for
conversion were the Eleanor Pardee Park well in conjunction with the El Camino well. Hence, it is assumed
that these two wells would collectively not exceed an annual production of 3,000 afy to avoid negative
impacts to the Santa Clara Valley groundwater basin.
The existing wells are currently equipped with chlorine disinfection whereas the San Francisco RWS Supply
utilizes chloramines as a secondary disinfectant. Mixing drinking water disinfected with chlorine with
drinking water disinfected with chloramine can create taste and odor issues. These issues can be
addressed through the use of ammonia injections. Using these wells on a regular basis will require
ammonia injections to convert to the use of chloramines as a secondary disinfectant in addition to more
robust treatment for elevated levels of iron (Fe), manganese (Mn) and TDS that are naturally present in the
groundwater and exceed secondary drinking water standards without additional treatment.
Several well water treatment options focused on the El Camino and Eleanor wells were considered as part
of the option development process, summarized below and schematically presented in Figure 3.6. These
options are:
.
.
.
.
Option 1: Blending with RWS Water (El Camino and Eleanor Wells).
Option 1B: Blending with RWS Water (El Camino Well only).
Option 2: Fe and Mn Treatment at Each Well (El Camino and Eleanor Wells).
Option 3: Fe and Mn Treatment at Each Well (El Camino and Eleanor Wells) plus blending with RWS
water.
.
.
Option 4: Fe, Mn, TDS, and Ammonia Treatment at Each Well (El Camino and Eleanor Wells).1
Option 4B: Fe, Mn, TDS, and Ammonia Treatment at Each Well (El Camino Well only).
It should be noted that blending (Options 1 and 1B) could be viable in the near term, whereas
constructing treatment facilities (Options 2, 3, 4, and 4B) would take more time. While Options 1 and 1B
are expected to meet water quality standards and be the most cost-effective groundwater options, the
higher mineral concentration in groundwater will result in a poorer taste of the blended water and will
likely be less palatable to the public than the existing RWS supply. Additionally, the poorer-tasting
blended water will disproportionately affect customers located near the wells. Due to the poorer taste and
equity concerns, the City selected Option 4 for consideration in this OWP to achieve the highest possible
water quality that is most similar to the water quality of the existing RWS Supply. Although only
groundwater treatment Option 4 is considered as part of the Portfolio Evaluation in this OWP, Appendix C
contains cost information for both Options 1 and 4.
1 This option is carried forward in the OWP for portfolio analysis.
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Treatment Option 4 would require the construction of treatment facilities at both the El Camino and
Eleanor wells including pressurized Fe/Mn filtration and reverse osmosis (RO) membranes. It is assumed
that pumped groundwater would be used for backwashing in this facility. Additionally, a dedicated
Reverse Osmosis (RO) concentrate line would be constructed from each well to the RWQCP effluent
discharge location to dispose of both RO and Fe/Mn concentrate. As with all options included in this
OWP, if this option is selected and further pursued, it is recommended that the City conduct further
studies to refine the details of the option, including treatment and RO concentrate disposal needs.
The water produced by the El Camino and Eleanor wells would be regularly tested and evaluated to verify
compliance with water quality standards. Implementation of this alternative will also likely require ongoing
coordination with Valley Water and a new permit with the California Division of Drinking Water (DDW) to
convert selected wells from emergency status to be used on a regular basis.
Figure 3.6 Groundwater Treatment Option Schematics
Valley Water is the Groundwater Sustainability Agency for the Santa Clara Valley Groundwater Basin and
levies a groundwater production charge (GPC) per acre-foot of water (Palo Alto 2017). The GPC was
developed from 10-year projections released in the FY 2022-23 Protection and Augmentation of Water
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Supplies (PAWS) report developed by Valley Water (Valley Water, 2022). The PAWS report anticipates that
the GPC will more than double from the 2023 rate of $1,724/af to $4,147/af by 2032, reflecting
approximately 9.5 percent annual escalation. Valley Water projects this increase to primarily pay for critical
capital program needs including water treatment plant upgrades and dam seismic retrofit work. It is
assumed that this escalation rate slows after 2032 to reflect typical annual inflation rates of 3-4 percent
more closely since Valley Water’s projection only covers a 10-year period.
3.4.4.2 Costs
Costs developed in the 2017 WIRP ranged from $1,400/af to $2,200/af and were initially developed in a
2000 Long Term Water Supply Study completed by Carollo Engineers (Carollo, 2000). The OWP refined
and escalated WIRP costs to present day values of $1,900/af for Option 1 to $4,700/af for Option 4. The
majority of the unit cost for both groundwater options is associated with GPC, which is part of the O&M
cost, and totals approximately $5 million per year as shown in Table 3.2. Moreover, treatment Option 4
would require the treatment facilities shown in Figure 3.6 including the filtration for Iron and Manganese
removal and the reverse osmosis for TDS removal; these facilities would add O&M cost to operate
(e.g., chemicals, backwash water, and energy costs) as well as nearly $50M in capital investments for
treatment facilities which are assumed to be located with the City parks where the wells are located ($0
for land acquisition). This option has $46,000 budgeted for personnel costs based upon an escalation of
the estimated labor costs in the 2000 Carollo study. However, it would also require one additional FTE to
run the treatment facility, and several staff would need treatment certifications. Additional cost estimate
details for each treatment option can be found in Appendix C.
With the selection of treatment Option 4 and corresponding unit cost of $4,663/af, this option receives a
cost score of one (1). For the remainder of the One Water Plan, “Groundwater” refers to Option 4 with
Fe, Mn, TDS, and Ammonia Treatment at the El Camino and Eleanor Wells.
3.4.4.3 Estimated Yield
The estimated annual capacity of each well, as obtained from the 2017 WIRP, is summarized above in
Table 3.4. However, as noted above, groundwater modeling completed in 2018 as a component of the
Northwest County Recycled Water Strategic Plan estimated the City could pump 3,000 afy of groundwater
from the Santa Clara Valley Groundwater Basin for supply without negative impacts to the aquifer (Todd
Groundwater 2018). The groundwater option assumes 5 percent of the water extracted is lost as Fe/Mn
filter backwashing and 20 percent is lost through RO treatment, for total losses of 25 percent. This reduces
the yield for this option to 2,250 afy. Hence, the corresponding estimated yield score is three (3).
3.4.4.4 Supply Reliability
Because Valley Water manages the basin in Santa Clara County, and because Valley Water relies heavily
on the State Water Project and Central Valley Project for imported water supplies, there is a high
likelihood that Valley Water will call for voluntary or mandatory water use reductions during droughts.
Valley Water has the ability to restrict pumping under the Sustainable Groundwater Management Act.
However, Valley Water has not used that authority. Valley Water Board Resolution 18-04 outlines the
process that would need to be followed prior to using that authority (Valley Water, 2021). This
groundwater option does not substantially increase nor decrease water supply reliability for the City
compared to imported RWS water during dry years. Hence, the supply reliability score is two (2).
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3.4.4.5 Total Screening Score
Receiving a total screening criteria score of six (6), this option will move forward to the portfolio
evaluation stage as described in Section 3.5.
3.4.5 New Irrigation Wells
3.4.5.1 Description
This option was initially investigated as part of the Northwest County Recycled Water Strategic Plan. The
findings were documented in a technical memorandum (TM) titled Using Groundwater to Irrigate City
Parks, which evaluated the installation of irrigation wells at the following City sites (W&C, 2020a):
.
.
.
.
.
Main Library and Garden.
Rinconada Park/W. Hays Elementary.
El Camino Park.
Eleanor Pardee Park.
Peers Park.
The 2020 TM selected these sites for evaluation because they are the locations of the existing City
emergency water supply wells. However, the 2020 TM concluded it would be more feasible to drill new
shallower, smaller irrigation wells rather than convert the existing emergency supply wells. The capacity of
the existing emergency supply wells is higher than what would be required for these irrigation wells.
Moreover, the capacity and system pressure of the emergency supply wells are not likely compatible with
the smaller irrigation infrastructure, posing a risk of system damage or severe leakage. The 2020 TM
concluded that it would be more practical to install new, smaller irrigation wells and allow the City to
maintain the emergency supply wells. The 2020 TM assumed the new irrigation wells would rely on the
shallow unconfined aquifer using wells of up to a maximum of 200 feet deep and could produce roughly
200 gpm.
Figure 3.7 shows the locations of the potential new irrigation well sites. The shallow and deep aquifers are
separated by extensive clay deposits, preventing groundwater from moving easily between the two
aquifers. Therefore, the shallow irrigation wells are not expected to have substantial impact on the deep
aquifer (Todd Groundwater, 2018). Water from the shallow wells would be used for landscape irrigation of
the co-located park, garden, and/or (sport) fields. Some sites were eliminated from consideration due to
proximity to areas of known groundwater contamination. The 2020 TM notes that the groundwater within
Palo Alto is generally appropriate for non-potable uses. Since the water would be used for irrigation, it is
assumed that treatment would not be needed. Should this option be pursued, shallow groundwater closer
to the San Francisco Bay is noted to have higher TDS that may not be suitable for irrigation. Installation of
a RO treatment facility for partial TDS removal using blending may be required but is not currently
considered in this option.
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Figure 3.7 Potential New Irrigation Well Sites
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3.4.5.2 Costs
The OWP escalates the costs developed in the 2020 TM to September 2023 values. The escalated capital
costs amount to approximately $200,000 per well installed. This cost includes well construction, well
equipping (electrical, pumps, surface improvements), and conversion of site irrigation system to
non-potable use. Anticipated escalated annual O&M costs are approximately $10,000 for all five wells.
This cost includes power, testing, pump and well servicing. Cost estimates do not include likely
requirement to develop a hydrogeologic assessment by a professional geologist and submit it together
with the well application to Valley Water (the Groundwater Sustainability Agency).
Similar to the groundwater option, this option also includes an annual Valley Water groundwater
pumping charge. The pumping charge is volumetric, so actual costs will depend on the volume of water
pumped. The groundwater pumping charge was developed from 10-year projections released in the
Valley Water PAWS report (Valley Water 2022).
A cost estimate summary of the key cost components is shown in Table 3.9, while a detailed cost estimate
for this option can be found in Appendix C. As shown, the estimated total 2023 unit cost is $3,107/af,
resulting in a cost score of two (2).
3.4.5.3 Estimated Yield
It is assumed that the irrigation wells would cover the total annual irrigation demand at the five identified
parks with a total estimated irrigation demand of 54 afy as shown in Table 3.5. This table lists the size of
the parks and the historical average irrigation demand of each site. It should be noted that the size of
each park represents the total area and that the portion of irrigated area varies greatly between parks due
to the presence/absence of playgrounds, tennis courts, picnic areas, recreation buildings, etc.
Table 3.5 City Park Irrigation Demands
Site Size
(acres)
Irrigation Demand
(afy)
Main Library and Garden
Rinconada Park/W. Hays Elementary
El Camino Park
2.3
19.0
12.2
9.6
9.6
12.4
6.8
Eleanor Pardee Park
Peers Park
10.9
14.7
54.4
4.7
Total Demand N/A
Data Sources:
(1) Northwest County Recycled Water Strategic Plan, Using Groundwater to Irrigate City Parks TM (W&C, 2020).
(2) City of Palo Alto historical irrigation records from 1/1/2018 through 4/1/2022.
The total yield for this project is dependent on the number of wells drilled. For the purposes of this
evaluation, it is assumed that wells would only be installed at the previously identified five sites. However,
the City could choose to drill additional wells at other sites where irrigation is needed. Based on a total
estimated yield of 54 afy for five wells, the estimated yield score is one (1).
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3.4.5.4 Supply Reliability
Valley Water manages the basin in Santa Clara County. Because Valley Water relies heavily on the State
Water Project and Central Valley Project for imported water supplies, there is a high likelihood that Valley
Water will call for voluntary or mandatory water use reduction during droughts. This groundwater option
does not substantially increase nor decrease water supply reliability for the City compared to imported
RWS water during dry years. Hence, the supply reliability score is two (2).
3.4.5.5 Total Screening Score
Receiving a total screening criteria score of five (5), this option will not move forward to the portfolio
evaluation process as described in Section 3.5. While the unit costs associated with the option are
competitive with RWS water supply, the low yield and neutral reliability during drought years make this
option less attractive than other options.
As previously noted, this option was based on the 2020 Using Groundwater to Irrigate City Parks TM,
developed as a component of the Northwest County Recycled Water Strategic plan, which studied
installation of irrigation wells only at sites with existing emergency supply wells. It is acknowledged there
could be refinements made to this option, including considering installing irrigation wells at additional
park sites. Conversations with City staff deemed this exercise not worth further exploration in this OWP.
3.4.6 DPR with Palo Alto Facility
3.4.6.1 Description
This DPR option would use advanced treated recycled water (purified water) to directly supplement the
potable water supply for Palo Alto customers. As the California legislature passed DPR regulations in
December 2023, and regulations were approved through the administrative process effective
October 1, 2024, DPR is considered a feasible option in this OWP.
This option was developed as “Concept Option D1: Palo Alto Dedicated DPR” as part of the 2019 Recycled
Water Strategic Plan (RWSP) (W&C, 2019). This option would require the construction of a 4.2 mgd
Advanced Water Purification Facility (AWPF) near the RWQCP. Per the RWSP, the AWPF treatment process
is assumed to consist of full advanced treatment with the additions of ozone, BAF, and free chlorine
process steps. Full advanced treatment is assumed to consist of MF and RO. However, this process could
be modified provided it meets the approved DPR regulations including the 10:1 dilution requirement. It is
assumed that the RO concentrate produced by the RO process, would be disposed via the RWQCP’s
existing outfall to the San Francisco Bay without additional treatment.
A storage tank is included in this option to provide an engineered storage buffer between the AWPF and
the distribution system. The RWSP assumed that this storage tank could be located beneath the Palo Alto
Municipal Golf Course driving range and would be sized at 4.75 million gallons (MG) to provide 8 hours of
detention time. Additional analysis for storage sizing and blending throughout the treatment process is
needed to confirm that the DPR dilution requirements can be satisfied.
This option also includes approximately 2 miles of pipe to connect the AWPF with the storage tank and
the storage tank with the distribution system. A pump station would be required to convey purified water
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to storage and a second pump station would be needed to pump purified water from the storage tank
into the distribution system.
To augment declining wastewater flows to the RWQCP, this option could include the diversion of
groundwater pumped from two permanent dewatering sites to the RWQCP. These sites are located at the
Palo Alto City Hall and Oregon Expressway. These two sites are estimated to yield approximately 1 mgd of
untreated groundwater, which is currently discharged to the stormwater system (W&C, 2020b). Diverting
this flow from the City’s stormwater system to the wastewater system would beneficially increase RWQCP
flows by 1 mgd for the purpose of potable reuse. Dewatering flows that are put to beneficial use may be
subject to groundwater production charges. Palo Alto and Valley Water would need to work together on
this and the OWP does not include the cost of any such charges.
3.4.6.2 Costs
Costs for this option include nearly $117M in capital investments for treatment facilities, including the
AWPF, storage tank, two pump stations, pipelines connecting the AWPF, storage tank, and distribution
system, as well as over $11 million for land acquisition costs. The cost estimate also includes additional
monitoring and reporting needed to demonstrate protection of public health. It does not include the cost
of additional RO concentrate treatment as the City’s recent discussions with the Regional Water Quality
Control Board (RWQCB) indicate that RO concentrate may be directly discharged through the existing
RWQCP outfall without additional treatment. This may change in the future for numerous reasons and
should be verified during preliminary design or other early evaluations if this project moves forward. Land
acquisition cost, estimated by Palo Alto staff, has also been included in this option.
The RWSP unit cost estimate for this option was estimated to be $2,500/af. Escalating this cost from the
initial June 2018 estimate to September 2023, removing the cost of RO concentrate treatment, adding
land acquisition cost, and adjusting the yield (see section below) results in an updated unit cost of
$3,594/af. This unit cost results in a cost score of two (2).
3.4.6.3 Estimated Yield
Projected available flows from the RWQCP for all reuse options were prepared by City staff. In recent
years, wastewater flows have decreased due to drought and conservation. Using 2022 wastewater effluent
data and removing the flow required to maintain service to existing NPR customers, internal plant
processes, and environmental flow demands and adding in flows from the City’s permanent dewatering
sites, Palo Alto is projected to have approximately 5.6 mgd of effluent flow available for a local DPR
facility. The estimated available flows for reuse for all six partner agencies are shown in Table 3.6.
The flows presented in Table 3.6 are based on a low-flow scenario using 2022 flows. It should be noted
that these numbers were calculated based on the Addendum to Guaranteed Feed memo and assumption
that there would not be a local salt removal facility. Since the SSRF is now planned, the numbers
presented in Table 3.6 may differ.
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Table 3.6 2022 RWQCP Flows by Partner and Flow Available for Reuse
Influent
Available
Flow for
Reuse
including
Dewatering
Flow (mgd)
Internal
Plant
Process
Flow
Available
Flow for
Reuse
2022 RWQCP 2022 Environmental
Flow(2)Needed for
Existing NPR
(mgd)
Partner Agency Influent Flow
(%)
Influent
(mgd)(1)(mgd))(mgd)(mgd)
Mountain View
Palo Alto
39%
37%
11%
5%
5.87
5.68
1.73
0.78
0.78
0.36
15.20
3.00
0.31
0.00
0.00
0.00
0.00
3.31
0.58
0.56
0.17
0.08
0.08
0.04
1.50
0.19
0.19
0.06
0.03
0.03
0.01
0.50
2.10
4.62
1.50
0.67
0.68
0.31
9.88
2.1
5.62
1.5Los Altos
EPASD 0.67
0.68
0.31
10.88
Stanford 5%
Los Altos Hills 2%
Total
Notes:
(1) Flows estimated from RWQCP Reports database, not based on billings.
(2) Environmental flows reflect needs for Renzel Marsh and Horizontal Levee Pilot Project.
Consistent with the RWSP, the treatment yield is estimated at 75 percent, resulting in a net production
capacity of 4.2 mgd (75 percent * 5.62 mgd) or 4,723 afy of purified water produced from Palo Alto’s
wastewater effluent. This is a reduction from RWSP yield estimate of 5,300 afy due to the reduction in
flows to the RWQCP over the past decade.
It is important to note that the yield for this option assumes that Valley Water will not construct a regional
purification facility. Should a regional facility be constructed, Palo Alto agreed to send about half of their
wastewater effluent to the regional facility and would thus have less flow available for a local DPR facility.
Based on 2022 wastewater effluent data and as shown in Table 3.7, approximately 1.9 mgd would be
available for a local DPR plant should the Valley Water regional purification facility be constructed. This
would result in a potable water yield of approximately 1.4 mgd (75 percent * 1.88 mgd) or 1,600 afy.
Based on the maximum possible yield of 4,723 afy, this option receives a yield score of three (3). If Valley
Water decides to exercise the option to transfer a portion of the RWQCP’s treated effluent, this option
would not be feasible.
3.4.6.4 Supply Reliability
Implementing DPR would significantly increase the City’s water supply reliability during drought years, as
its source is wastewater that would continue to be generated during dry periods. Indoor water use, which
results in wastewater flows to the RWQCP, may slightly decrease during drought years due to indoor
conservation because of drought restrictions. However, the total available wastewater flow for DPR is not
expected to be substantially impacted. Since implementing this option would increase the City’s water
supply reliability during drought years, it receives a supply reliability score of three (3).
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Table 3.7 RWQCP Flows Available for Regional Purification Facility and Local Reuse
Available Flow for
Local Reuse
including Dewatering
Flow (mgd)
Flow to Regional
Purification Facility
(mgd)(2)
Available Flow for
Local ReuseAvailable Flow for
Reuse (mgd)(1)Partner Agency
(mgd)
Mountain View
Palo Alto
2.10
4.62
1.50
0.67
0.68
0.31
9.88
2.10
3.74
1.50
0.67
0.68
0.31
9.00
0.88 1.88
Los Altos
EPASD
Stanford
Los Altos Hills
Total 0.88 1.88
Notes:
(1) See Table 3.6 for calculation of estimated flows available for reuse.
(2) Total flow to Valley Water’s Regional Purification Facility would be 9 mgd, per the 2019 Partnership Agreement to Advance
Resilience Water Reuse Programs in Santa Clara County, a trilateral agreement between Valley Water, the City of Palo
Alto, and the City of Mountain View. Mountain View, Palo Alto, and Los Altos have agreed to send their proportion of
effluent from the RWQCP to Valley Water’s Regional Purification Facility. EPASD, Stanford, and Los Altos Hills have not yet
entered into such an agreement, but it is assumed for the purposes of this plan that these entities would also send their
proportion of effluent to the Regional Purification Facility.
3.4.6.5 Total Screening Score
Receiving a total screening criteria score of eight (8), this option will move forward to the portfolio
evaluation stage as described in Section 3.5. This score assumes that Valley Water does not exercise the
option to transfer treated effluent from the RWQCP to a regional water purification facility. Given DPR’s
high reliability during drought years, high potential yield, and moderate cost, it is an attractive option for
diversifying the City’s water supply portfolio, especially since the DPR Regulations are now approved,
providing clarity on treatment and dilution requirements.
3.4.7 DPR with Palo Alto Facility and the SSRF
3.4.7.1 Description
Similar to the DPR with the Palo Alto Facility, this option would use advanced treated recycled water
(purified water) to directly supplement the potable water supply for Palo Alto customers. The difference
between this option and the other Palo Alto Treatment Facility is that the treatment process would include
the Small Salt Removal Facility (SSRF), which is currently in the design phase, to reduce the salinity of the
recycled water currently produced at the RWQCP, as a pretreatment for the AWPF treatment processes.
The SSRF product water is referred to as permeate.
As shown in Figure 3.8, the SSRF pretreatment (green dashed line) would consist of ozone treatment
followed by BAC, while the SSRF (blue dashed line) would consist of MF and RO processes. The SSRF is
planned to be constructed in two phases with an ultimate capacity of 2.25 mgd to provide permeate to
both Palo Alto and the City of Mountain View, who would each be entitled to 25 percent and 75 percent
of the permeate, respectively.
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Figure 3.8 DPR with Palo Alto Treatment Facility and SSRF Option Schematic
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This option assumes construction of the full SSRF to produce 2.25 mgd of permeate, providing Palo Alto
with 0.56 mgd (630 afy) of supply capacity. This option would also include additional post treatment
processes (orange dashed line) to treat Palo Alto’s portion of the SSRF permeate to potable water quality
standards, providing 0.56 mgd of purified water supply to the City.
It should be noted that the ozone and BAF processes must be sized to treat the entire flow (assumed to
be 2.85 mgd) entering the SSRF, even though not all the SSRF permeate would be used for potable reuse.
Treatment processes downstream of the SSRF would be sized to only treat the 0.56 mgd of Palo Alto’s
share of the SSRF permeate.
To deliver the purified water to Palo Alto’s customers, this option also includes a conveyance pipeline to
connect the purified water with the City’s potable water distribution system just east of the 101 freeway as
well as a storage tank to meet the diluent requirements of the DPR regulations. Similar to the other DPR
and IPR options, it is assumed that RO concentrate may be directly discharged through the existing
RWQCP outfall without additional treatment. Valley Water and the City of Mountain View are paying the
capital cost for Phase 1 of the SSRF project. In addition, a low-interest State Revolving Fund loan and US
Bureau of Reclamation federal grant were secured. This option assumes Phase 2 will be built as well.
3.4.7.2 Costs
Costs for this option include a capital cost of nearly $49M for the ozone and BAF treatment based on the
AWPF in the RWSP (Option D1) with a capacity of 4.73 mgd but downsized to 2.85 mgd and adjusted
from the initial June 2018 estimate to September 2023 dollars. In addition, treatment costs for advanced
oxidation, free chlorine, MF/RO, water stabilization, and secondary UV disinfection are included.
Moreover, this option includes costs for a storage tank, two pump stations, pipelines between the
treatment processes and delivery to the potable water distribution system, as well as additional
monitoring and reporting needed to demonstrate protection of public health. It does not include the cost
of additional RO concentrate treatment as the City’s recent discussions with the RWQCB indicate that RO
concentrate may be directly discharged through the existing outfall. Land acquisition cost is also
estimated at $7.4M; however, the total land requirement was downsized to the smaller footprint needed
for this SSRF option compared to the original RWSP estimate and a lower unit land cost based on
information provided by City staff. The estimated unit cost of this option is $8,897 per acre-foot, resulting
in a cost score of one (1).
It should be noted that the pretreatment and SSRF would need to be sized to treat up to half of the
RWQCP recycled water production for other uses, not just the amount that Palo Alto would purify to
drinking water standards. This “oversizing” of the SSRF pretreatment (2.85 mgd) and SSRF treatment
(2.25 mgd) for a net delivery of 0.56 mgd for Palo Alto contributes to making this option more expensive
than the Palo Alto DPR option.
3.4.7.3 Estimated Yield
This option assumes a 2.25 mgd SSRF will be constructed; this flow is split between the Cities of Palo Alto
and Mountain View, with Palo Alto receiving 25 percent of the 2.25 mgd (0.56 mgd) and Mountain View
receiving the remaining 75 percent (1.69 mgd); Palo Alto's flow share (0.56 mgd) will be treated further to
produce 0.56 mgd of purified water for DPR. As the SSRF would be operated year-around, the estimated
yield of this option is 630 afy, resulting in a yield score of two (2).
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3.4.7.4 Supply Reliability
Implementing DPR would significantly increase the City’s water supply reliability during drought years, as
its source is wastewater that would continue to be generated during dry periods. Indoor water use, which
results in wastewater flows to the RWQCP, may slightly decrease during drought years due to indoor
conservation as a result of drought restrictions. However, the total available wastewater flow for DPR is
not expected to be substantially impacted. Since implementing this option would increase the City’s water
supply reliability during drought years, it receives a supply reliability score of three (3).
3.4.7.5 Total Screening Scores
Receiving a total screening score of six (6), this option will move forward to the portfolio evaluation
stage of the OWP analysis as described in Section 3.5. Despite DPR’s high reliability during drought years,
the combination of being highest unit cost option and providing only a limited yield, this option is not
very attractive compared to the other DPR options.
3.4.8 DPR with Regional Facility
3.4.8.1 Description
This option would consist of contracting with Valley Water to treat tertiary-treated wastewater (effluent)
from the RWQCP to drinking water standards and deliver that potable water to Palo Alto’s distribution
system. Critically, this option relies on Valley Water constructing a regional purification facility located in
Palo Alto that can produce purified water meeting DPR requirements. In 2021, Valley Water published
their Countywide Water Reuse Master Plan (CoRe Plan) that evaluates several potential options for
large-scale regional reuse (B&C, 2021). Valley Water’s goal is to produce 24,000 afy of purified water for
potable reuse by the year 2040, but the details, including the location and the water supply source, of the
facility are still in development. One potential option that Valley Water is planning is for Valley Water to
build an IPR facility located in Palo Alto. The facility would use RWQCP treated effluent and purify the
water for groundwater augmentation in Southern Santa Clara County.
In 2017, Palo Alto, along with other RWQCP partner agencies, agreed to provide Valley Water with an
option to receive a minimum flow delivery of an annual average of 9 mgd of effluent from the RWQCP for
use at a regional purification facility (Palo Alto 2019c). Of this 9 mgd, approximately 4 mgd would come
from Palo Alto. Valley Water would pay Palo Alto and other RWQCP partner agencies for this effluent.
Palo Alto reserved some of its effluent to be used in Palo Alto, either as a supply for an expanded
non-potable distribution system or for DPR. The existing agreement does not contemplate Valley Water
providing purified water to Palo Alto. The existing agreement does include a water supply option for Palo
Alto that includes an opportunity to provide Valley Water a notification of the need for additional water to
meet demands in Palo Alto’s service area up to an annual average of 3 MGD.
This option assumes that Palo Alto could negotiate a cost-based fee for Valley Water to produce purified
water for Palo Alto’s use by treating additional Palo Alto effluent. Under this option, Palo Alto could also
potentially receive purified water in lieu of some portion of the payment for the 4 mgd of effluent sent to
Valley Water for their own use. A schematic illustrating the major components of this option is shown in
Figure 3.9.
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Figure 3.9 DPR with Regional Treatment Facility Option Schematic
To augment declining wastewater flows to the RWQCP, this option could include the diversion of
groundwater pumped from two permanent dewatering sites to the RWQCP. These sites are located at the
Palo Alto City Hall and the Oregon Expressway. These two sites are estimated to yield approximately
1 mgd of untreated groundwater, which is currently discharged to the stormwater system (W&C, 2020b).
Diverting this flow from the City’s stormwater system to the wastewater system would beneficially
increase RWQCP flows by 1 mgd for the purpose of potable reuse.
It should be noted that if Valley Water exercises its option to transfer treated effluent from the RWQCP to
a regional purification facility, it would allow the possibility of this option, however it would impact the
yield of other reuse options. Since most of Palo Alto’s flow to the RWQCP would be sent to the Valley
Water regional purification facility, less flow would be available for other local reuse options.
3.4.8.2 Costs
The CoRe Plan includes cost estimates for three (3) DPR options that would produce purified water for
treated or raw water augmentation from the San Jose/Santa Clara Regional Wastewater Facility (SJ/SC
RWF). The CoRe plan also includes several IPR options using effluent from the RWQCP but does not
include a DPR-specific option using RWQCP effluent. The cost estimates developed for the SJ/SC RWF
DPR options are assumed to be most closely reflective of what this DPR from a regional facility option
would cost. The CoRe Plan does not include the cost of additional RO concentrate treatment. Per the
City’s recent discussions with the RWQCB, it was assumed that that RO concentrate may be directly
discharged through the existing outfall. The cost estimates developed in the CoRe plan for the DPR
options range from $2,500/af to $3,300/af. The estimated capital cost for this option is over $16M, with a
unit cost is $4,024/af, resulting in a cost score of two (2).
3.4.8.3 Estimated Yield
Projected available flows from the RWQCP for all reuse options were prepared by City staff. Despite a
decreasing trend of wastewater flows due to the success of water conservation programs, Palo Alto is
projected to have approximately 1.9 mgd of available effluent flow for reuse including dewatering flow
(see Table 3.7) that could potentially be wheeled through Valley Water’s regional purification facility, if
constructed with DPR capabilities and located in Palo Alto and returned as potable water. Assuming a
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production efficiency of 80 percent to align with losses from advanced treatment assumed in the CoRe
Plan, the City could receive approximately 1.5 mgd (80 percent * 1.9 mgd) or 1,769 afy of potable water
back from the regional purification facility, resulting in a yield score of two (2).
3.4.8.4 Supply Reliability
Purchasing water from a DPR program would significantly increase the City’s water supply reliability
during drought years as its source is wastewater that would continue to be generated during dry periods.
Although indoor water use, and thereby wastewater flows to the RWQCP, may decrease during drought
years due to additional voluntary water conservation or mandated drought restrictions, wastewater
influent flows are not expected to be substantially impacted. Since implementing this option would
increase the City’s water supply reliability during drought years, it receives a supply reliability score of
three (3).
3.4.8.5 Total Screening Scores
Receiving a total screening score of seven (7), this option will move forward to the portfolio evaluation
stage of the OWP analysis as described in Section 3.5. Given DPR’s high reliability during drought years
and relatively moderate cost, it is an attractive option for diversifying the City’s water supply portfolio. The
yield for this option is moderate and subject to uncertainty with potential fluctuations in future
wastewater flows to the RWCQP, but still substantial enough to positively impact the City’s overall water
supply availability. The cost for this option could increase if RO concentrate must be treated instead of
discharged through the RWQCP’s outfall pipeline as assumed here.
3.4.9 IPR with Groundwater Injection
3.4.9.1 Description
The IPR option would utilize purified water for groundwater injection followed by extraction from the
groundwater basin. This option was developed as “Concept Option C1: Palo Alto Dedicated IPR” as part of
the 2019 RWSP and the accompanying IPR Feasibility Evaluation (Todd Groundwater, 2018). Similar to the
Palo Alto Dedicated DPR option, this option would require the construction of a 2.5 mgd AWPF near the
RWQCP. The AWPF treatment process is assumed to include full advanced treatment consisting of MF/RO
and a disinfection process such as advanced oxidation and/or ultraviolet (UV) disinfection. However, IPR
would not need to include ozone and BAF processes required for DPR. Figure 3.10 shows a schematic
illustrating the major components of this option.
A new pump station would need to be constructed to pump purified water to injection wells that would
inject the purified water into the deep aquifer to augment groundwater. The purified water then would
mix with the local groundwater and the mixture would be extracted through the City’s existing
groundwater wells and treated for use in the City’s water distribution system. In this way, the groundwater
acts as an environmental buffer between the advanced treatment and drinking water treatment.
Approximately 5.6 miles of pipeline is needed to convey purified water to the five (5) recommended
injection well sites. The five proposed injection well sites for this option are located in the northern part of
the City in the general vicinity of and upgradient to the City’s existing groundwater wells. The locations of
the injection wells assumed buffer zones around the groundwater production wells (Todd Groundwater,
2018).
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Figure 3.10 IPR with Groundwater Injection Schematic
This option assumes the same wellhead treatment as the conversion of emergency groundwater wells
Option 4, which includes iron, manganese, and TDS treatment to make the groundwater quality
comparable to the City’s existing RWS water supply. The OWP assumes one additional well is necessary
for IPR because of the increased capacity relative to the City’s use of groundwater without IPR
groundwater augmentation.
3.4.9.2 Costs
Costs for this option include nearly $189M in capital costs, including the AWPF, pump station, pipelines
connecting the AWPF to the injection wells, injection wells, and wellhead treatment. The unit cost estimate
for this option was estimated to be $3,300/af in the 2019 RWSP. Estimated costs in the RWSP did not
include wellhead treatment, land acquisition cost, or the cost of additional RO concentrate treatment.
Wellhead treatment costs estimated elsewhere in the RWSP and land acquisition costs of $7.4M have
been added by City of Palo Alto staff for this option. The cost of RO concentrate treatment is not included
as the City’s recent discussions with the RWQCB indicate that RO concentrate may be directly discharged
through the existing RWQCP outfall without additional treatment. This may change in the future and
should be verified during preliminary design or other early evaluations if this project moves forward.
Escalating this cost from the initial June 2018 estimate to September 2023 and adding costs associated
with wellhead treatment and land acquisition results in a unit cost of $4,992/af. This unit cost results in a
cost score of one (1).
3.4.9.3 Estimated Yield
Based on the IPR Feasibility Evaluation, it is estimated that injecting 2,900 afy of purified water into the
groundwater basin results in a total groundwater pumping yield of approximately 5,900 afy (3,000 afy of
existing operating yield plus the added IPR yield of 2,900 afy). Accounting for RO concentrate losses
associated with treatment and backwash the estimated yield is 5,150 afy.
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It is important to note that the yield for this option assumes that Valley Water does not construct a
regional purification facility. Should a regional facility be constructed, Palo Alto has agreed to send a
portion of their wastewater flow to the RWQCP to the regional facility and would have 1.9 mgd available
for IPR via groundwater injection (see Table 3.7). Should the Valley Water regional purification facility be
constructed, this would result in purified water production of approximately 1.4 mgd (1,600 afy) that
would be available for groundwater injection. This would result in an estimated total yield of
approximately 4,600 afy when added to the 3,000 afy safe yield from the groundwater basin.
Based on the maximum possible yield of 5,150 afy, this option receives a yield score of three (3). If Valley
Water exercises the option to transfer a portion of the RWQCP’s treated effluent, this option would not be
feasible based on the available flow.
3.4.9.4 Supply Reliability
Implementing IPR would significantly increase the City’s water supply reliability during drought years, as
its source is wastewater that would continue to be generated during dry periods. Indoor water use, which
results in wastewater flows to the RWQCP, may slightly decrease during drought years due to
conservation or drought restrictions, but is not expected to be substantially impacted. However, these
impacts would be lessened with the recharge of purified water. Due to the increase in supply reliability
offered by water reuse, this option receives a supply reliability score of three (3).
3.4.9.5 Total Screening Score
Receiving a total screening criteria score of seven (7), this option will move forward to the portfolio
evaluation stage of the OWP analysis as described in Section 3.5. Given IPR’s high reliability during
drought years and high potential yield it is an attractive option for diversifying the City’s water supply
portfolio. However, this option is more expensive than the Palo Alto DPR option, which may make it less
attractive despite having similar yield.
3.4.10 NPR with Phase 3 Extension to Foothills
3.4.10.1 Description
This option would extend the City’s existing non-potable reuse (NPR) system by constructing the Phase 3
pipeline to south Palo Alto. This option was previously developed as “Concept Option A2: NPR Palo Alto
Phase 3 Extended to Foothills” as part of the 2019 RWSP (W&C, 2019). This option was first recommended
in the 2008 Palo Alto Recycled Water Facility Plan (Palo Alto, 2008) and reassessed through the 2018
Phase 3 Business Plan and the 2018 Preliminary Design Report (Palo Alto, 2018c). Based on the
assessment completed in the 2019 RWSP, this option also includes extending the Phase 3 pipeline to
serve additional customers in Los Altos Hills as well as Foothills Nature Preserve. Demands from 2019
need to be re-evaluated to exclude any non-functional turf at commercial properties consistent with the
upcoming legislative requirement of Assembly Bill (AB) 1572.
The NPR system expansion would consist of approximately 15 miles of pipeline built off the existing
30-inch diameter recycled water backbone on Embarcadero Road. The existing recycled water pump
station at the RWQCP would need to be expanded and three (3) additional booster pump stations would
need to be added to the NPR system to accommodate the additional recycled water flows.
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To serve non-potable recycled water to additional customers, it is assumed that the proposed 2.25 mgd
small salt removal facility (SSRF) must be constructed near the RWQCP to enhance the quality of the
recycled water by lowering the effluent TDS. The City of Palo Alto Recycled Water Project Environmental
Impact Report (EIR) certified in 2015 includes mitigation measures for the Phase 3 pipeline that require
TDS of recycled water to be reduced below 600 mg/L before the recycled water is sent to new customers,
notably Stanford Research Park (EIR Palo Alto, 2006). The design of the Phase 1 of the SSRF facility is
currently underway, and construction is anticipated to be completed before 2030. The design for Phase 1
has a capacity of 1.125 mgd and includes the footprint and connections for the Phase 2 expansion to
2.25 mgd, which would involve new piping, mechanical and electrical equipment.
A schematic illustrating the major components of this option is shown in Figure 3.11, while the NPR
pipeline alignment for the corresponding option (Concept Option A2 - NPR Palo Alto Phase 3 Extended to
Foothills) is shown in Figure 3.3 of the Northwest County Recycled Water Strategic Plan (W&C, 2020b).
Figure 3.11 NPR with Phase 3 Extension to Foothills Schematic
3.4.10.2 Costs
The cost estimate for this option includes a capital cost of $148.5M for the construction of Phase 2 of the
SSRF, four (4) pump stations, and 15 miles of pipeline extending to new customers. The RWSP unit cost
estimate for this option was $3,400/af. Escalating the estimate and using recent Palo Alto pipeline cost
estimates, brings the unit cost of this option to $9,685/af. This results in a cost score of one (1).
3.4.10.3 Estimated Yield
This option would serve non-potable water to approximately 115 new customers with an estimated
demand of 1,100 afy. It should be noted that one anchor user that accounts for approximately 15 percent
of the total demand for this NPR expansion currently relies on groundwater for its water supply and does
not receive water service from Palo Alto. Groundwater is projected to be less costly than recycled water.
Hence, the yield of this option could be lower, which would increase the unit cost. Based on the estimated
yield of 1,100 afy, this option results in a yield score of two (2).
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3.4.10.4 Supply Reliability
This option does not substantially increase water supply reliability for the City. While recycled water is a
drought-resilient source, NPR water is used primarily for irrigation which is likely to be restricted in
drought years. The neutral nature of this option’s effect on the City’s supply reliability results in a
reliability score of two (2).
3.4.10.5 Total Screening Score
Receiving a total screening score of five (5), this option will not move forward to the portfolio
evaluation process as described in Section 3.5. The unit costs associated with the option are high, and
there is lower yield associated with this option compared to the IPR or DPR options considered. These
considerations, coupled with the neutral reliability during drought years, make this option less attractive
than others.
3.4.11 Graywater Capture and Reuse
3.4.11.1 Description
Graywater is defined as water from residential indoor water use collected from washing machines,
showers, bathtubs, and bathroom sinks. While graywater contains soaps and salts, it is generally
considered safe for plant irrigation. Graywater systems are commonly referred to as “laundry to
landscape” or “showers to flowers,” as depicted in Figure 3.12. Graywater systems can be implemented
with varying levels of complexity. Some systems are as simple as a pipe system conveying water directly
from the appliances to irrigation areas or systems, while others employ some level of treatment such as
filtration or aeration.
The City, in conjunction with Valley Water, administers an existing graywater rebate program known as
“Laundry-to-Landscape.” This program provides a rebate of up to $400 to incentivize single-family
residential customers to install laundry graywater irrigation systems on their properties. The program
currently has an adoption rate of three total laundry graywater systems installed from FY2019 to FY2023.
This option seeks to expand the implementation of the City’s existing graywater capture and reuse
program both at customer homes as well as a selection of City facilities. If this expanded implementation
is successful, the City could consider expanding this program into other customer classes that may have
more complexities associated with them, such as multi-family homes or office buildings.
For the purposes of this evaluation, it was assumed that 1 percent of single-family homes would adopt a
laundry graywater system by 2040. Based on the SFR forecast presented in the City’s 2020 UWMP (Palo
Alto, 2021), 1 percent of the projected number of single-family accounts in 2040 (18,161 accounts) would
equate to approximately 180 single-family laundry graywater systems. In addition, based on discussions
with the City, it was assumed that City’s fire stations (6 total) and community pool (1 total) would install
graywater systems, encompassing a total of seven City sites. To encourage higher graywater program
uptake, this option would require additional staff time for further community outreach activities and
assistance in implementing graywater systems at City facilities.
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Source: Valley Water News (Valley Water, 2024)
Figure 3.12 Graywater System “Laundry-to-Landscape” Schematic
3.4.11.2 Costs
Costs were developed for graywater system installation in both single-family homes and at City sites. As
this plan only considers costs incurred by the City, Palo Alto’s portion of the “Laundry-to-Landscape”
rebate amount offered was the assumed total capital cost for single-family home installations. Although
the total rebate to the customer via Valley Water’s incentive program is $400/system, Palo Alto’s cost
share of this rebate is only $200/system. Hence, the cost for the City used for the purpose of the OWP is
$200 per system installed. As the City would bear the full capital cost of graywater systems installed at City
sites, costs were developed from researching several vendor sites for the estimated full cost of a
graywater system. The cursory review showed that home-installed graywater system costs vary widely
from $400 to $10,000 per system, reflecting the range of system complexity. The upper end of this range
($10,000 per system) was used as the total capital cost per City installed systems as it is assumed these
may be larger and more complex than single-family home systems. It is assumed that the primary
ongoing O&M costs associated with this option will be from City employee time associated with
community outreach and guidance in installing and maintaining these systems at City facilities (0.25 FTE).
With an assumed useful life of 15-years, rounded cost is estimated at $8,215/af, which results in a
corresponding cost score of one (1).
3.4.11.3 Estimated Yield
Yield was calculated using assumptions from the San Francisco Graywater Design Manual for Outdoor
Irrigation. The manual estimates 60 gallons per day (gpd) of graywater is produced from washing
machines from a four-person home (SFPUC, 2018). According to the City’s 2022 Census estimates for Palo
Alto, the average householder size is approximately 2.62 persons. The anticipated graywater yield was
therefore reduced proportionally to reflect the smaller SFR household size in Palo Alto, equating to
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roughly 40 gpd. Moreover, it was assumed that each non-SFR City site would produce double the yield for
an SFR home or approximately 80 gpd. The total estimated yield with these assumptions is 125 af
cumulatively from FY 2024 through 2045 (22 years) and thus averages 6 AF annually. This results in a yield
score of one (1).
3.4.11.4 Supply Reliability
While this water supply would provide irrigation for single-family homes and select City sites, this option
does not increase potable water supply for the City. In addition, implementation of these graywater
systems would decrease wastewater supply available for potential reuse projects. Overall, this option does
not substantially increase nor decrease water supply reliability for the City compared to imported RWS
water during dry years, resulting in a supply reliability score of two (2).
3.4.11.5 Total Screening Score
Receiving a total score of four (4), this option will not move forward to the portfolio evaluation process
as described in Section 3.5. The low yield and correspondingly high unit cost make this option less
attractive than others.
3.4.12 Residential Rainwater Capture
3.4.12.1 Description
The City, in conjunction with Valley Water, administers a
rain barrel rebate program, providing financial incentives
($70/barrel) for customers to install a rain barrel on their
property (Palo Alto, 2023c). Rain barrels installed on
residential properties typically range in size from 40 to
200 gallons. The barrels collect water draining off building
roofs. Collected rainwater is then used for landscape
irrigation with no treatment required. For this evaluation, it
was assumed that 5 percent of single-family homes would
have adopted a rain barrel by 2040. Using the SFR account
forecast presented in the 2020 UWMP (Palo Alto, 2021), 5
percent of the estimated number of single-family accounts
in 2040 (18,161 accounts) would equate to approximately
900 single family rain barrel installations in the City.
This option seeks to expand the implementation of the
City’s existing rain barrel program at residential properties.
If this expanded implementation is successful, the City
could consider expanding this program into other
customer classes that may have more complexities Source: City of Palo Alto Rain Barrel Rebate
Program website (Palo Alto, 2023c).associated with them, such as City owned facilities, multi-
family homes, or office buildings.
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3.4.12.2 Costs
Costs were developed for rain barrel installation in single-family homes. As this plan only considers costs
incurred by the City, Palo Alto’s rain barrel rebate amount offered was the assumed total capital cost for
single-family home installations. This equates to $35 per rain barrel installed. It is assumed that O&M will
be negligible as the only cost being considered is the costs incurred by the City, not the customer. Even
such, these systems are simple and would likely only require a replacement at the end of the estimated
useful life, rather than ongoing O&M. It is assumed that the primary ongoing O&M costs associated with
this option will be from City employee time associated with community outreach and guidance in
installing these systems at City facilities (0.25 FTE).
With an assumed useful life of 15-years for each rain barrel, the unit cost is estimated at $58,300/af, which
results in a corresponding cost score of one (1). Similar to the enhanced water conservation programs,
this unit cost is calculated using the average yield in the planning period of 0.7 afy, rather than the
anticipated yield of 1.4 afy in 2045. Moreover, although rain barrels provide a non-potable water source
that offsets potable water, the main purpose is to promote water awareness, rather than water supply,
making residential rainwater capture beneficial in different ways. Additionally, rain barrels reduce
stormwater runoff and enhance stormwater quality.
3.4.12.3 Estimated Yield
Available, historical rainfall data was collected for Palo Alto from the National Oceanic and Atmospheric
Administration (NOAA) Climate Data Online site from 2000 to 2018. To estimate the amount of rainfall
available to fill a rain barrel, the data was refined to remove storm events that were too small (less than
half an inch of rainfall) or too close together (less than 5-days apart). This was to capture storm events
that would adequately fill an average sized rain barrel (approximately 100 gallons) and avoid consecutive
storm events when it is unlikely customers would need to irrigate or when rain barrels would already be
full.
Using the NOAA data, there are approximately 5 inches of qualifying rainfall per year. It was assumed that
each inch of rainfall would fill a 100-gallon rain barrel equating to 500 gallons collected per barrel per
year. Assuming one rain barrel per house, a total city-wide saturation of approximately 5 percent of
single-family accounts in 2040 would equate to 900 rain barrels, resulting in an average of 450,000 gallons
of rainwater being collected for irrigation per year. This equates to total yield of 1.4 afy through potable
water offset by year 2045 resulting in a yield score of one (1). It should be noted that the average yield
in the planning period is 0.7 afy due to the gradual increase of water savings associated with rain barrel
distribution.
3.4.12.4 Supply Reliability
This option would not increase water supply reliability for the City because there will be inherently fewer
and less intense rainfall events in drought years, limiting the ability to fill the rain barrels. Collectively, this
option will not increase supply reliability for the City, and therefore, it received a supply reliability score
of one (1).
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3.4.12.5 Total Screening Score
Receiving a total screening criteria score of three (3), this option will not move forward to the portfolio
evaluation process as described in Section 3.5. The low yield and low reliability during drought years make
this option less attractive than others. Given the low capital cost to install a rain barrel, it is recommended
the City continue to provide the existing rebate program to residents and businesses.
3.4.13 Green Stormwater Infrastructure
3.4.13.1 Description
This option would involve the installation of green stormwater infrastructure (GSI) throughout Palo Alto at
City facilities and parking lots and on City streets. Potential project locations previously identified as part
of the City’s Green Stormwater Infrastructure Plan (Palo Alto, 2019a) were used to estimate cost, yield and
supply reliability for this Plan. City staff continue to identify and prioritize locations throughout Palo Alto
to meet stringent regional permit requirements and Sustainable and Climate Action Plan (S/CAP) goals
(Palo Alto, 2023b). Thus, this estimate is based on limited data and may underestimate benefits from GSI
over the next 30 years. According to the Plan, types of infrastructure that may be installed include:
.
.
.
.
Bioretention areas installed between the curb and sidewalk or as curb extensions to slow traffic.
Pervious pavement in sidewalks, pedestrian walkways, bike lanes, or parking lanes.
Underground stormwater storage facilities for storm runoff and rainwater capture.
Tree well filters designed to capture street runoff and planted with a special soil to allow infiltration.
In general, for the purposes of this Plan, GSI utilizes stormwater runoff to irrigate aesthetic landscape
features for immediate or later use and recharges the underlying groundwater basin where soil conditions
permit. Figure 3.13 shows a schematic example of how GSI, such as curb cuts and permeable pavement,
can provide irrigation water and groundwater recharge.
3.4.13.2 Costs
The OWP developed estimated unit costs using green street project concepts developed for the One
Water LA 2040 Plan (Carollo, 2018). The planning level costs presented in this plan were escalated to
present day dollars using the ENR regional index ratio. Costs were developed based on a comparison of
the cost estimating methods presented in the Enhanced Watershed Management Plans (EWMPs) for the
Ballona Creek, Dominguez Channel, Marina del Rey, Santa Monica Bay, and Upper Los Angeles River
watershed. Parameters considered include the green streets footprint, static capture volume, volume of fill
media, and underdrain volume. In addition, the annual O&M cost for green street projects was estimated
as 6 percent of the project capital cost. Unit costs, on average, are $1,000/linear feet of green street or
$17,000/af stormwater captured (Carollo, 2018). Unit costs for below-ground facilities in parking lots and
City facility sites could be less costly due to possibly easier construction with fewer potential utility
conflicts and traffic control needs, however the unit cost is still expected to exceed $4,000/af due to the
limited yield these GSI projects generate with California hydrology. Hence, the corresponding cost score
is one (1).
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Figure 3.13 Green Stormwater Infrastructure Schematic
3.4.13.3 Estimated Yield
The green stormwater infrastructure projects included in the estimated yield include the high and medium
priority projects identified in the City’s Green Stormwater Infrastructure Plan as depicted in Figure 3.14.
The average yield per mile was estimated at 6 afy/mile, while there are approximately 5 miles of GSI
anticipated, resulting in approximately 30 afy. With a total estimated yield of this option being less than
100 afy, the estimated yield score is one (1).
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Figure 3.14 Planned Green Stormwater Infrastructure Projects
3.4.13.4 Supply Reliability
This option would not increase water supply reliability for the City, because the availability of stormwater
is inherently less in drought years, limiting the amount of stormwater that could be captured. And
although the captured stormwater will offset some potable water demand for irrigation, the timing and
availability of stormwater does not align with the timing of irrigation demands. Even if stormwater is
captured and used post storm-events, the amount of storage that is practical is limited to provide water
supply for days or possibly weeks of irrigation demand, rather than months. Specifically in drought
periods, stormwater supply – even when temporarily stored – is therefore unlikely to increase supply
reliability during summer months when higher temperatures increase evaporation rates and result in
higher demands. Moreover, depending on the type of green infrastructure implemented, some GSI
solutions require year around watering and therefore actually increase water demands during periods
when stormwater is not available. This option will not increase supply reliability for the City, and therefore,
received a supply reliability score of one (1).
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3.4.13.5 Total Screening Scores
Receiving a total screening criteria score of three (3), this option will not move forward to the portfolio
evaluation process as described in Section 3.5. The high unit cost, low yield and low reliability during
drought years make this option less attractive than others. The City will continue to install green
stormwater infrastructure to meet regional permit requirements and sustainability goals separate from the
OWP. Furthermore, these types of projects typically provide multiple benefits to the community other
than water supply, such as stormwater quality enhancement and flood mitigation. Because these projects
may have a co-benefit of water supply in some years, some water utility funding may be appropriate.
3.4.14 Multi-Source Storage
3.4.14.1 Description
This option would consist of the construction of large, below-grade storage tanks at City parks to store
water for irrigation. The storage facilities would be filled with stormwater, recycled water, and/or water
from two permanent dewatering sites at City Hall and the Oregon Expressway. The primary irrigation
supply would be stormwater during wet months, supplemented with dewatering water. If needed,
recycled water could be pumped into the tanks when needed during dry months. If dewatering flows are
put to beneficial use, they are subject to groundwater production charges and Palo Alto would need to
work with Valley Water on this issue. Groundwater production charges associated with dewatering water
are not included in the OWP.
The permanent dewatering sites are areas where the groundwater levels are shallow and must frequently
be dewatered to prevent damage to property and infrastructure. Each site is equipped with a pump
station and water is directed into the storm drain system, which discharges into the San Francisco Bay
(W&C, 2020b). At the Oregon Expressway site, water is also discharged to the sanitary sewer.
The following parks were selected to site potential storage tanks based on their proximity to either the
two permanent dewatering sites or the City’s existing recycled water system:
.
.
.
.
.
Peers Park.
Heritage Park.
Hoover Park.
Johnson Park.
Ramos Park.
The selected parks, dewatering sites, and existing recycled water pipelines are shown on Figure 3.15. The
storage tanks were sized to meet 4 hours of each park’s maximum irrigation demand using yearly
irrigation data provided by the City. This option includes a pipeline and small pump station to transport
water from the dewatering site or recycled water system to the storage tank.
Each multi-source storage site would require that a Title 22 Engineering Report be prepared, which would
require approval by both the City as well as the State’s DDW Title 22 Engineering reports require extensive
staff time throughout the process, including ongoing inspections and cross-connection testing.
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3.4.14.2 Costs
Capital costs were developed using a typical planning level unit cost for small concrete tank storage of
$7 per gallon, escalated by a factor of 2.0 to account for a buried tank, and scaled based on the estimated
size tank at each site. Additional capital expenditures are required for treatment, pipelines, and a pump
station, as well as the costs to complete a Title 22 Engineering Report. Although recycled water would not
require additional treatment to be used for irrigation, stormwater comprised of urban runoff typically
includes a wide range of pollutants from heavy metals to bacteria and high levels of sediment. It is
assumed that a basic and compact treatment system would be needed to blend the recycled water,
dewatering water, and stormwater prior to a filtration and disinfection step such as UV. For the purposes
of this high-level evaluation, O&M costs were not estimated. The anticipated tank size, total capital cost,
and unit cost for each park are summarized in Table 3.8. As shown, the average unit cost is estimated at
$39,700/af, which results in a corresponding cost score of one (1).
Table 3.8 Multi-Source Storage Option Sizing and Cost Estimates
Unit Cost
(capital and
O&M cost)
($/af)
Estimated
Tank Size
(Gallons)
Conveyance Total Capital Irrigation
Demand(2)
(afy)
Backup |
Water Supply
Source(3)
Park Name Pipeline Cost(1)
($M)Length (LF)
Peers 68,000
45,000
63,000
40,000
28,000
245,000
3,000
4,000
4,000
3,000
1,500
15,500
$4.7
$5.5
$5.8
$4.3
$2.3
$22.6
$30,900
$49,100
$36,400
$55,400
$34,100
$39,700
10.3
7.6
Dewatering water
Recycled water
Dewatering water
Dewatering water
Dewatering water
N/A
Ramos
Hoover
Johnson
Heritage
10.7
5.2
4.8
Total 38.6
Notes:
(1) All capital costs include a 2.25 multiplier of the estimated construction cost to account for construction cost contingencies,
contractor overhead, profit, and insurance; predesign, design, construction management, administrative, environmental, and
legal expenses; and engineering services during construction.
(2) Data Source: 2018-2022 annual irrigation data, provided by the City of Palo Alto.
(3) Backup supply source to be used in the event that stormwater is not available.
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Figure 3.15 City Parks Selected for Multi-Source Storage Tank
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3.4.14.3 Estimated Yield
Total yield is dependent on-site selection, and the number of sites implemented. It is assumed that the full
irrigation demand would be met at each park by captured stormwater, with either dewatering water or
recycled water acting as a backup supply if stormwater is not sufficient to meet demands. As noted in
Appendix B, the total annual yield from the City Hall and Oregon Expressway dewatering sites is estimated
to be at least 200 MG/year (over 600 afy), which is ample to serve the irrigation demands of the parks in
the vicinity of these sites (Johnson, Peers, Heritage, and Hoover Parks have a total demand of 31 afy).
Ramos Park, with a demand of 7.6 afy, would likely be served by the existing recycled water system as a
backup supply. The annual irrigation demand for the five parks proposed is listed in Table 3.8. As shown,
the total estimated yield is 39 afy resulting in an estimated yield score of one (1).
3.4.14.4 Supply Reliability
This option would increase water supply reliability for the City. The proposed water sources (dewatering
water and recycled water) are both drought-resilient and constructing storage for irrigation use would
provide a new use for this water. Since implementing this option would increase the City’s water supply
reliability during drought years, it receives a supply reliability score of three (3).
3.4.14.5 Total Screening Score
Receiving a total screening criteria score of five (5), this option will not move forward to the portfolio
evaluation process as described in Section 3.5While this option would be reliable in drought conditions,
the high unit cost and low yield make it less attractive than others. The City may still consider
implementing storage tanks to store stormwater to meet regional permit requirements and provide
multiple benefits to the community, environment, and water quality.
3.4.15 San Francisco Bay Desalination
3.4.15.1 Description
Several studies have been completed to evaluate desalination as a new water supply using either the San
Francisco Bay or brackish groundwater as a source. In the evaluation process in the Bay Area Water Supply
and Conservation Agency’s (BAWSCA) 2015 Long-Term Reliability Water Supply Strategy Phase II Report
(CDM Smith, 2015), Bay water desalination scored higher than groundwater desalination. Additionally,
because Palo Alto has access to relatively clean groundwater with low salinity, utilizing groundwater as
described in previous options would be more cost effective and less operationally complex than
undertaking groundwater desalination. Moreover, groundwater pumping is subject to a GPC imposed by
Valley Water, which adds a significant O&M cost component to all groundwater options as shown in
Table 3.9. For this reason, this OWP only considers San Francisco Bay desalination and not brackish
groundwater desalination.
This option would consist of the construction of a local small-scale desalination plant owned and
operated by Palo Alto, with an open bay water intake in the San Francisco Bay. The desalination plant is
assumed to be located near the existing RWQCP, and the open bay water intake would extend
approximately one mile offshore. A schematic of this option is shown in Figure 3.16.
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Figure 3.16 Small scale Bay Water Desalination for Palo Alto Schematic
Per the 2015 BAWSCA Strategy, it is assumed that the desalination facility would have a 50 percent
recovery rate and RO concentrate could be discharged through the existing Palo Alto RWQCP outfall.
However, as technology has advanced since the completion of the 2015 BAWSCA Strategy, it is likely that
recovery rates will be higher, potentially reducing facility sizing and costs from the original estimate. It is
assumed that the potential increase in recovery rate would reduce intake capacity, and that the
desalination plant would be sized for the same product water capacity. The cost assumption for the
regional or local small-scale desalination facility is based on continuous operation as reverse osmosis
membranes used in desalination plants perform better when not operated intermittently and to minimize
unit cost. Brine disposal will be a key issue for Palo Alto staff to address including considering public input
and environmental considerations.
3.4.15.2 Costs
Cost estimates from the BAWSCA Strategy for construction of a 15-mgd regional desalination facility form
the basis of the cost estimate for this option. The BAWSCA Strategy estimated the unit cost for open bay
desalination to be between $2,100/af and $2,400/af. This cost range reflects variations in conveyance and
disposal pipe length estimates for various plant configuration options. These cost estimates do not
include land acquisition and RO concentrate disposal costs due to uncertainty around these items in the
BAWSCA Report. It is assumed that RO concentrate would be discharged from the existing RWQCP outfall
and thus would not incur significant cost. It does not include the cost of additional RO concentrate
treatment as the City’s recent discussions with the RWQCB indicate that RO concentrate may be directly
discharged through the existing RWCQP outfall without additional treatment. This may change in the
future for numerous reasons and should be verified during preliminary design or other early evaluations if
this project moves forward. Palo Alto City staff have estimated land acquisition cost for a desalination
facility at a cost of $43.6M for this option. Due to economies of scale of a 15 mgd facility (BAWSCA study)
compared to the 5-mgd facility proposed for the OWP option, unit costs were adjusted with a factor of
1.6 based on the Seawater Desalination Costs publication from the WateReuse Association (WaterReuse,
2012). Escalating this cost from the initial February 2015 estimate to September 2022 results in a capital
cost of nearly $252M. Adding in costs related to land acquisition results in a unit cost range of $6,768/af.
Hence, the estimated unit cost of this option is $6,768/af, resulting in a cost score of one (1).
CITY OF PALO ALTOONE WATER PLAN 3-45
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3.4.15.3 Estimated Yield
The estimated yield for a Palo Alto-owned desalination facility is assumed to have a treatment capacity of
5 mgd (5,600 afy). Consistent with BAWSCA’s Long Term Reliable Water Supply Strategy Final Report (CDM
Smith, 2015), an annual operational yield of 80 percent was assumed, resulting in a net yield of 4,480 afy.
Hence, the yield of this option results in a yield score of three (3).
3.4.15.4 Supply Reliability
Desalination would increase water supply reliability for the City as the proposed water source (San
Francisco Bay water) would not be impacted by drought conditions. Thus, this option receives a supply
reliability score of three (3).
3.4.15.5 Total Screening Score
Receiving a total screening score of seven (7), this option will move forward to the portfolio process as
described in Section 3.5. Given desalination’s high reliability during drought years, high potential yield,
and moderate cost, it is an attractive option for diversifying the City’s water supply portfolio.
3.5 Options Costs and Screening Conclusions
Table 3.9 and Table 3.10 summarize the unit cost estimates for each of the options that made it to the
screening process. The costs are shown in 2023 dollars and include capital costs, O&M costs, and total
unit costs expressed in $/af. These unit costs are a combination of the annualized capital and O&M costs
divided by the yield of the option. In addition, the GPC and energy costs are broken out separately from
the unit O&M cost as these components are a significant portion of the total unit cost for the options
involving groundwater pumping and advanced treatment, respectively.
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Table 3.9 Unit Cost Estimate of all Screened Options - 1
RWS
Emergency Emergency
Supply Well Supply Well New Irrigation
Conversion Conversion
(Option 4)(1) (Option 1)(1)
DPR with
Palo Alto
Treatment
Facility(1)
DPR with
Regional
Treatment
Facility(1)
Enhanced
Conservation Conservation
Phase 1(1)
3.4.2
Enhanced
Supply Option Supply Wells(1)Phase 2(1)
3.4.3Section3.4.1 3.4.4 3.4.4 3.4.5 3.4.6 3.4.7
Total Capital Cost
Capital Cost ($)$0
$0
$0
$0
$0
$0
$0
$0
$0
$49,760,760 $1,532,363 $993,011
$0
$105,257,000 $16,410,000
Land Acquisition Cost ($)
Amortized Capital and Land Cost ($/yr)
Total O&M Cost
$0 $0 $11,463,000
$7,592,804
$0
$3,408,068 $92,395 $64,597 $1,067,494
GPC ($/yr)N/A
$27,726,660
$0
N/A
$188,176
N/A
N/A
$639,142
N/A
$5,172,000 $5,172,000 $93,096
$6,822
$3,276
$0 $0
O&M Cost ($/yr)$1,811,749
$99,964
$212,010
$99,964
$9,305,267
$74,733
$6,049,640
$270,999Energy Cost ($/yr)
Total Unit Cost(1)
Total Annual Cost ($/yr)
Project Yield (afy)
$27,726,660
12,546(2)
$0
$188,176
602(3)
$0
$639,142 $10,491,781 $5,576,369 $167,791
54
$16,972,804 $7,117,134
330(4)
$0
2,250
$1,515
$2,299
$805
3,000
$31
4,723
$1,608
$0
1,769
$603
$0
Capital Cost Unit Cost ($/af)
GPC Unit Cost ($/af)
O&M Unit Cost ($/af)
Energy Unit Cost ($/af)
$1,196
$1,724
$126
$0 $0 $0 $1,724
$71$2,210
$0
$312
$0
$1,939
$0
$1,970
$16
$3,420
$153
$4,024
$44 $33 $61
Total Unit Cost ($/af)$2,210 $312(2)$1,939(3)$4,663 $1,859 $3,107 $3,594
Notes:
(1) Supply Options Cost Estimating Details (see Appendix C). Cost Estimates generally reflect 2023 dollars and construction cost estimates are adjusted to ENR Index for the
greater San Francisco Areas of 15,490 (September 2023). Cost numbers are not rounded from the calculations presented in Appendix C to avoid inconsistencies in rounded
values. However, these are planning level (aka “order of magnitude”) cost estimates with a typical estimating accuracy of -50% to +100% due to limited level of project
information often coupled with significant uncertainties at this planning stage.
(2) Yield for RWS Supply based on forecasted Palo Alto demand of 12,546 af in 2045 under medium growth scenario.
(3) The unit cost of $312/af is based on the average yield of 602 afy in the period 2025 to 2045, rather than projected yield of 724 afy in 2045.
(4) The unit cost of $1,939/af is based on the average yield of 330 afy in the period 2025 to 2045, rather than projected yield of 618 afy in 2045.
CITY OF PALO ALTOONE WATER PLAN 3-47
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Table 3.10 Unit Cost Estimate of all Screened Options - 2
DPR with
Palo Alto
Facility and
the SSRF
NPR with
Phase 3
Extension to
Foothills(1)
San
Francisco
Bay
IPR with
Groundwater
Injection(1)
Graywater
Capture and Rainwater
Reuse(1)
3.4.11
Residential Green
Stormwater Multi-Source
Storage(1)Supply Option
Capture(1) Infrastructure(1)Desalination(1)
Section 3.4.8 3.4.9 3.4.10 3.4.12 3.4.13 3.4.14 3.4.15
Total Capital Cost
Capital Cost ($)
Land Acquisition Cost ($)
$48,900,000 $188,900,000 $148,510,000
$7,400,000 $7,400,000 $0
$0
$0
$0
$0
$0
$0
$4,080,000
$0
$22,630,000 $251,832,599
$0 $43,560,000
$1,472,114 $19,215,712Amortized Capital and Land Cost ($/yr) $3,662,396 $12,769,597 $9,660,789 $265,410
Total O&M Cost
Groundwater Production Charge ($/yr)
O&M Cost ($/yr)
$0 $5,671,960
$6,213,260
$1,054,780
$0 $0
$46,650
$0
$0
$43,251
$0
$0
$240,000
$0
$0
$60,000
$0
$0
$1,897,644
$45,045
$992,271
$82,592
$9,827,073
$1,281,486Energy Cost ($/yr)
Total Unit Cost
Total Annual Cost ($/yr)
Project Yield (afy)
$5,605,085 $25,709,597 $10,653,060 $46,650
6
$43,251
0.7
$505,410
30
$1,532,114 $30,324,272
630
$5,813
$0
5,150
$2,480
$1,101
$1,206
$205
1,100
$8,783
$0
39
$38,125
$0
4,480
$4,289
$0
Capital Cost Unit Cost ($/af)
GPC Unit Cost ($/af)
O&M Unit Cost ($/af)
Energy Unit Cost ($/af)
$0 $0 $8,847
$0$0 $0
$3,012
$71
$902
$75
$8,215
$0
$58,321
$0
$8,000
$0
$1,554
$0
$2,193
$286
Total Unit Cost ($/af)$8,897 $4,992 $9,685 $8,215 $58,321 $16,847 $39,679 $6,768
Notes:
(1) Supply Options Cost Estimating Details (see Appendix C).Cost Estimates generally reflect 2023 dollars and construction cost estimates are adjusted to ENR Index for the
greater San Francisco Areas of 15,490 (September 2023) Cost numbers are not rounded from the calculations presented in Appendix C to avoid inconsistencies in rounded
values. However, these are planning level (aka “order of magnitude”) cost estimates with a typical estimating accuracy of -50% to +100% due to limited level of project
information often coupled with significant uncertainties at this planning stage.
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The information presented for each of the potential options discussed in this chapter to support the
allocated screening criteria scores are summarized in Table 3.11, while the results of the options screening
scoring are listed in Table 3.12.
Table 3.11 Options Comparison
Unit Cost
in 2023 dollars(1)
($/af)
Estimated Yield
in 2045
Increases Supply
Reliability in
Drought Years?
Category Option
(afy)
Imported Water RWS Supply $2,210
$312
12,546
724
Neutral
YesConservation
Groundwater
Water Reuse
Enhanced Conservation - Phase 1
Enhanced Conservation - Phase 2
Groundwater
$1,939
$4,663
$3,107
$3,594
$8,897
$4,024
$4,992
$9,685
$8,215
$58,321
$16,847
$39,679
$6,768
618 Yes
2,250
54
Neutral
Neutral
Yes
New Irrigation Wells
DPR with Palo Alto Facility
DPR with Palo Alto Facility and SSRF
DPR with Regional Facility
IPR with Groundwater Injection
NPR with Phase 3 Expansion
Graywater Capture and Reuse
Residential Rainwater Capture
Green Stormwater Infrastructure
Multi-Source Storage
4,723
630 Yes
1,769
5,150
1,100
10
Yes
Yes
Neutral
Neutral
No
Onsite Water
Capture/Reuse 1.4
Stormwater
Storage
30 No
39 Yes
Desalination
Notes:
Bay Water Desalination 4,480 Yes
(1) Cost numbers are not rounded from the calculations presented in Appendix C to avoid inconsistencies in rounded values. However, these
are Class 5 planning level (aka “order of magnitude”) cost estimates with a typical estimating accuracy of -50% to +100% due to limited
level of project information often coupled with significant uncertainties at this planning stage.
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Table 3.12 Summary of Screening Scores
Supply
Reliability in
Drought
Estimated
Yield
Total Move toCosts
($/AF)Category Option Screening Portfolio
Score Evaluation?(afy)Years
Imported Water RWS Supply 2
3
3
1
2
2
1
2
1
1
1
1
1
1
1
3
2
2
3
1
3
2
2
3
2
1
1
1
1
3
2
3
3
2
2
3
3
3
3
2
2
1
1
3
3
7
8
8
6
5
8
6
7
7
5
4
3
3
5
7
Yes
Yes
Yes
Yes
No
Conservation
Groundwater
Water Reuse
Enhanced Conservation - Phase 1
Enhanced Conservation - Phase 2
Groundwater
New Irrigation Wells
DPR with Palo Alto Facility
DPR with Palo Alto Facility and SSRF
DPR with Regional Facility
IPR with Groundwater Injection
NPR with Phase 3 Expansion
Graywater Capture and Reuse
Residential Rainwater Capture
Green Stormwater Infrastructure
Multi-Source Storage
Yes
Yes
Yes
Yes
No
Onsite Water
Capture/Reuse
No
No
Stormwater
Storage
No
No
Desalination
Notes:
Bay Water Desalination Yes
(1) Cost numbers are not rounded from the calculations presented in Appendix C to avoid inconsistencies in rounded values.
However, these are Class 5 planning level (aka “order of magnitude”) cost estimates with a typical estimating accuracy
of -50% to +100% due to limited level of project information often coupled with significant uncertainties at this planning
stage.
Table 3.12, the top 8 ranked new local options, excluding the existing RWS Supply, are:
.
.
.
.
.
.
.
.
Enhanced Conservation - Phase 1 (score 8).
Enhanced Conservation - Phase 2 (score 8).
DPR with Palo Alto Facility (score 8).
DPR with Regional Facility (score 7).
IPR with Groundwater Injection (score 7).
Bay Water Desalination (score 7).
Groundwater (score 6).
DPR with Regional Facility and SSRF (score 6).
The options that passed both the pre-screening and screening process were developed in more detail as
described in Chapter 4. These options were also used to compile portfolios that were evaluated against
each other as described in Chapter 5. The options that did not pass the screening process are not
considered in the remainder of this OWP but could be of interest for re-evaluation by the City if
conditions change.
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CHAPTER 4 OPTION EVALUATION
This chapter starts with a brief introduction, followed by a description of the evaluation criteria,
sub-criteria and criteria weighting factors used to compare and evaluate the nine (9) options that
passed through the pre-screening and screening steps described in Chapter 3. Subsequently, the option
evaluation using these (sub)criteria is described. This chapter concludes with a summary of the option
evaluation results with and without the Valley Water Transfer.
4.1 Introduction
As described in Chapter 3 and depicted on Figure 4.1, the development of the recommended strategy
used in this One Water Plan (OWP) consists of four main steps. This chapter describes the third step of
this process, the option evaluation, as indicated with the orange box. The nine (9) options that passed
through the pre-screening and screening steps described in Chapter 3 are as follows:
1. Regional Water Supply (RWS) Supply.
2. Enhanced Conservation – Phase 1.
3. Enhanced Conservation, Phase 2.
4. Groundwater.
5. Palo Alto Indirect Potable Reuse (IPR).
6. Direct Potable Reuse (DPR) with Palo Alto Facility.
7. DPR with Regional Facility.
8. DPR with Regional Facility and the Small Salt Removal Facility (SSRF).
9. Bay Water Desalination.
Figure 4.1 Options Evaluation Process
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Detailed cost estimates were prepared for each of the nine (9) options using a variety of source
documents and planning-level sizing of the key components. The cost estimating method used for each
option was tailored to the amount of readily available information for both project sizing and costs, as
well as the type of option. In general, the following three types of cost estimating methods were used:
.Cost Escalation Method: Costs are based on previous studies and are updated to account for
escalation or anticipated changes in time for labor, material, and equipment using Engineering
News-Record (ENR) index ratio of the original cost basis and the September 2023 ENR index of
15,490 for the San Francisco Area.
.
.
Programmatic Cost Estimate: Cost estimate for options that are gradually implemented over time,
resulting in an incremental increase in water savings and costs. These programs (e.g., water
conservation) typically do not have a significant capital/ infrastructure component.
Bottom-Up Calculation: Full conceptual level cost estimate for projects that have not been evaluated
prior to this OWP and/ or options that do not have a previous cost estimate.
The detailed cost estimates for each option are presented in Appendix C, along with the general cost
estimating assumptions and the methodology used for each option. It should be noted that some options
use a combination of methods. For example, for the Palo Alto DPR option, the cost escalation method was
used for the majority of cost estimate using information presented in the 2019 Northwest County
Recycled Water Strategic Plan. However, the reverse osmosis concentrate (ROC) treatment was removed,
reflecting a revised assumption that RO concentrate can be discharged via the existing Regional Water
Quality Control Plant (RWQCP) outfall under the current discharge permit. Lastly, land acquisition and
conveyance pipeline costs were removed and then added in with the more recent unit costs assumptions
of the Bottom-Up Calculation method.
4.2 Evaluation Criteria
The criteria used to evaluate the options in this OWP were developed to reflect a wide range of
perspectives. This includes input from City staff and the community via polling and discussion during the
first two (2) rounds of stakeholder engagement meetings, as described in Chapter 1. The four (4) main
evaluation criteria build upon the screening criteria described in Chapter 3 and include:
1. Reliability.
2. Unit Cost.
3. Environmental Benefits.
4. Ease of Implementation.
The Environmental Benefits and Ease of Implementation criteria each have multiple sub-criteria described
in more detail below. The three Environmental Benefits sub-criteria are 1) Reduced Reliance on the
Tuolumne River, 2) Efficient Use of Water and 3) Ecological Benefits. The Ease of Implementation
sub-criteria are 1) Implementation Timeline, 2) Operational Complexity, and 3) Public Acceptance. The
four evaluation criteria, along with their respective sub-criteria, and the methods used for scoring the
options are described in the following Subsections 4.2.1through 4.2.4.
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An excel-based portfolio evaluation tool (Evaluation Tool or Tool) was developed to compare options that
passed through the screening process as described in Chapter 3. Each option is scored for each of the
evaluation criteria using either qualitative or quantitative metrics. The qualitative criteria scores are
directly input by the user in the Evaluation Tool, while the quantitative criteria scores are calculated within
the Evaluation Tool based on the objective option attributes (e.g., yield, unit cost) and user other inputs
(e.g., demand scenario and cost year). The Tool has a default set of criteria weighing factors (percentages)
to reflect the relative importance of each criterion. These weighting factors can be modified by the user to
vary the level of relative importance between the criteria as desired. Details regarding Evaluation Tool
functionality are provided in Appendix D.
4.2.1 Reliability
This criterion assesses an option’s dry year yield and, thus, its ability to alleviate a supply shortage due to
a cutback from the RWS. It is a quantitative criterion calculated on a linear scale, considering the dry year
yield for each option as the primary metric. Scores range from 1 (zero dry year yield) to 5 (largest dry year
yield). Scores for options with yields between these endpoints were calculated proportionally to the
option’s dry year yield. For example, if Option A has the largest dry year yield of 5,000 acre-feet per year
(afy) and Option B has a dry year yield of 2,500 afy, Option A will receive a score of 5 and Option B will
receive a score of 2.5. The RWS option is assigned a score of 1 in this assessment because it cannot
increase supplies during a cutback from the RWS.
Options were evaluated solely based on dry year yield, which is calculated by multiplying the option’s
estimated yield during a dry year by the dry year reduction selected by the user of the Tool. The rationale
for the dry year reductions used in this analysis is documented in Section 5.1 of Chapter 5. Subsequently,
portfolios are assessed according to the extent that they mitigate a shortage caused by a cutback from
the RWS, which can vary depending on the Evaluation Tool scenario and portfolio inputs selected by the
user. More information on portfolio scoring is provided in Chapter 5.
4.2.2 Unit Cost
This criterion measures the capital and operating cost of each option, expressed as a Unit Cost in dollar
per acre-foot ($/af), which is comprised of the annualized capital and O&M cost divided by the average
annual yield. Quantitative scoring for this criterion uses a linear scale. The option with the lowest cost
receives a score of 5, indicating the most cost-effective option, while the option with the highest cost
receives a score of 1, representing the least cost-effective option in terms of unit cost.
Similar to the Reliability criterion, other options are scored proportionally based on unit cost. For example,
if Option A has a Unit Cost of $10,000/af, Option B has a Unit Cost of $1,000/af, and Option C has a Unit
Cost of $5,000/af, Option A will receive a score of 1, Option B will receive a score of 5, and Option C will
receive a score of 3.2.
These scores reflect the comparative costs based on the specified cost year in the Evaluation Tool; they
will change dynamically if the user changes the cost year or if the user changes which options are
included in the Evaluation Tool.
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4.2.3 Environmental Benefits
The Environmental Benefits criterion is separated into the following three (3) sub-criteria to reflect a range
of environmental considerations relating to options that reflect community values around protecting the
environment and promoting sustainability:
1. Reduced Reliance on the Tuolumne River.
2. Efficient Use of Water.
3. Ecological Benefits.
These three sub-criteria are further described in more detail in the sections below.
4.2.3.1 Reliance on Tuolumne
In 2018, Palo Alto’s City Council adopted a position in support of the Bay-Delta Plan, reflecting the
importance of reducing the City’s reliance on Tuolumne River flows to protect ecosystem health. This
evaluation sub-criterion reflects this goal by evaluating the capability of the options to provide supplies
that are independent of the RWS Supply. Similar to the Reliability and Unit Cost criteria, options are
scored against this quantitative sub-criterion proportionally between the highest yield option and
zero yield. On this scale, the highest annual average yield receives a score of 5, indicating a maximum
reduction of Reliance on Tuolumne River supply from the RWS. Conversely, if a source fails to yield any
non-RWS Supply, it receives a score of 1. For example, if Option A has the largest normal year yield of
5,000 afy and Option B has a normal year yield of 2,500 afy, Option A will receive a score of 5 and
Option B will receive a score of 2.5. RWS Supply is assigned a score of 1, as it represents full Reliance on
Tuolumne River.
The Reliance on Tuolumne sub-criterion is differentiated from the Reliability criterion in that Reliance on
Tuolumne focuses on the normal year yield, and thus the City’s typical Reliance on Tuolumne River. In
contrast, the Reliability criterion focuses on the dry year yield and the City’s ability to meet demand when
facing a significant cutback of RWS Supply in dry years.
4.2.3.2 Efficient Use of Water
This sub-criterion scores options based on using water efficiently to elevate options that increase water
use efficiency or water reuse, in contrast to options that rely on fresh sources of water that could have
other uses and environmental benefits. The qualitative scoring system ranges from 5 (very efficient) to
1 (not efficient with known negative environmental impact). Overall, scoring favors the adoption of
strategies that prioritize water conservation and sustainable water use. The definition for each score for
the Efficient Use of Water sub-criterion is summarized in Table 4.1.
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Table 4.1
Score
Efficient Use of Water Sub-Criterion Scoring
Definition
Overall Rating – Very Efficient
Reduces water use5 (best)
Overall Rating – Efficient
Uses recycled water that would otherwise be discharged as treated effluent4
Overall Rating – Neutral3
2
Uses water from a non-potable (e.g., saline) water source or uses a blend of recycled water and freshwater
Overall Rating – Not Efficient
Uses freshwater or brackish water from an existing source of water supply
Overall Rating – Not Efficient with Known Negative Environmental Impact
Uses freshwater from an untapped source of water supply1 (worst)
4.2.3.3 Ecological Benefits
This sub-criterion considers the potential benefits and impacts to ecosystem and watershed health, as well
as energy use for each option. For this qualitative criterion, a score of 5 denotes the highest level of
environmental benefit, with significant benefits to ecosystem restoration, improved watershed health, and
reduced energy usage. The scoring definitions for the Ecological Benefits sub-criterion are summarized in
Table 4.2. It should be noted that to avoid double counting with the “Reliance on the Tuolumne River”
criterion, the ecological benefit of reduced flows are called out in the option evaluation results tables
(Table 4.7 through Table 4.15) but are not considered in the scoring.
Table 4.2
Score
Ecological Benefits Criterion Score Definitions
Definition
Overall Rating – Significant Benefits
5 (best) . Significantly restores ecosystems and/or improves watershed health
. Significantly reduces energy use
Overall Rating – Moderate Benefits
4
3
2
. Moderately restores ecosystems and/or improves watershed health
. Moderately reduces energy use
Overall Rating – Neutral
. Limited benefit or negative impact to ecosystems and/or watershed health
. No change in energy use
Overall Rating – Moderate Negative Impacts
. Moderate negative impact to ecosystems and/or watershed health
. Moderately increases energy use
Overall Rating – Significant Negative Impacts
1 (worst) . Significant negative impact on ecosystems and/or watershed health
. Significant increase in energy use
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4.2.4 Ease of Implementation
The Ease of Implementation criterion is separated into the following three (3) sub-criteria to capture
various aspects of project or program implementation:
1. Implementation Timeline.
2. Operational Complexity.
3. Public Acceptance.
These three sub-criteria are further described in the sections below.
4.2.4.1 Implementation Timeline
This sub-criterion captures a qualitative assessment of potential implementation timelines and feasibility
across various water options, ranging from a score of 5 denoting the quickest and most straightforward
implementation to a score of 1 indicating the longest and most complex process.
A score of 5 suggests readiness for immediate implementation within a year, while a score of 1 indicates
the longest timeline of over 10 years, necessitating extensive feasibility studies, lengthy design and
permitting processes, complex construction, and extensive public engagement efforts. This criterion
facilitates informed decision-making by providing clarity on the practicality and timelines associated with
each option. The definitions for each score for this criterion are summarized in Table 4.3.
Table 4.3
Score
Implementation Timeline Sub-Criterion Score Definitions
Definition
Ready for immediate implementation (< 1 year)
. Feasibility studies performed (or not needed)
5 (best) . No design efforts or California Environmental Quality Act (CEQA) analysis anticipated
. Short implementation duration
. No regulatory constraints
Fast Implementation possible (< 2 years)
. Few new studies and/or preparations are needed
4
3
. Short duration or simple construction anticipated
. No CEQA analysis and/or extensive permitting is required
. Approval not dependent on non-City entities
Typical Implementation Timeline (2-5 years)
. Some new studies and/or preparation needed
. 2-5 years design and construction duration anticipated
. Potential need for CEQA analysis and/or multiple non-City permits required
. Potential need for involvement of non-City entities
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Score
2
Definition
Moderate Implementation Timeline (5-10 years)
. Moderate studies and/or preparation needed
. Multi-year design, CEQA analysis, and permitting process anticipated
. Approval dependent on collaboration with non-City entities
. Requires change in customers’ water use behavior
. Likely requires some level of public engagement
Long Implementation Timeline (>10 years)
. No or only limited feasibility studies performed
1 (worst) . Long design, CEQA analysis, and permitting process anticipated (5-10 years)
. Lengthy or complex construction anticipated
. Extensive public engagement efforts required
4.2.4.2 Operational Complexity
The qualitative Operational Complexity sub-criterion evaluates the operational ease and staffing
requirements associated with different options, ranging from a score of 5 denoting the most
straightforward operations requiring little to no additional staffing or training, to a score of 1 indicating
the most challenging operations demanding extensive staffing and training. The definitions for each score
for this criterion are summarized in Table 4.4.
Table 4.4Operational Complexity Sub-Criterion Score Definitions
Score Definition
Very straightforward
. Little to no operation required
. No additional staff needed
. No additional training needed
Straightforward
5 (best)
4 . Some additional staff may be needed
. No or only minor additional training/certifications required
Typical3
2
. Some additional staff and training needed
Difficult
. More staff and training needed
Very difficult
. Extensive, 24/7 operation needed
. Significant staff needed1 (worst)
. Significant training and/or certifications needed
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4.2.4.3 Public Acceptance
The qualitative Public Acceptance sub-criterion evaluates the anticipated public reception and community
support for options, ranging from highly favorable perceptions to unfavorable ones. A score of 5 indicates
an anticipated highly favorable outlook by the general public, while a score of 1 indicates the high
likelihood of unfavorable public perceptions or potential significant public opposition. This framework
helps gauge the potential community and stakeholder response to each project. The definitions for each
score for this sub-criterion are summarized in Table 4.5.
Table 4.5
Score
Public Acceptance Sub-Criterion Score Definitions
Definition
Highly Favorable
5 (best) . Expect the public and other stakeholders to perceive the project very positively
. Expect the public and other stakeholders to embrace the project quickly as being good for the City
Favorable4. Expect the public and other stakeholders to perceive the project positively
Neutral/ Mixed
3 . Expect the public and other stakeholders to have a mixed opinion of the project, with some support
and some opposition
Less Favorable
2 . Expect the public and other stakeholders to perceive the project negatively
. Expect opposition from the public and other stakeholders on the project
Not Favorable
1 (worst) . Expect the public and other stakeholders to perceive the project very negatively
. Expect significant opposition from the public and other stakeholders on the project
4.3 Criteria Weighting
Criteria weighting refers to assigning the relative importance or priority to different criteria or factors
when making a decision or evaluation. Each of the evaluation criteria and sub-criteria described in
Section 4.1 is given a weight, which represents its relative importance compared to the other criteria and
sub-criteria. The weight assigned to each criterion is based on feedback received from City and
community stakeholders gathered in meetings with each group, as well as from the results of an online
survey open to all community members. In live polling and in the online survey, respondents were asked
to rank draft evaluation criteria based on their relative importance or preference, reflecting respondents’
priorities and values.
The results of the weighting exercises for each group are shown in Table 4.6, along with an average
weight across all three (3) respondent groups and a selected weight for use in the OWP. The selected
weight is based on the average weight, rounded to the nearest 5 percent. It should be noted that
respondents were asked to provide input on the main four (4) criteria, not the sub-criteria, as those were
defined and refined later in the planning process.
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Table 4.6 Evaluation Criteria Weighting
Community
Meeting
Weight
Community
Online Survey
Weight
Average
WeightCriteriaCity Weight Selected Weight
Reliability.41%
25%
24%
10%
32%
25%
23%
20%
29%
28%
22%
21%
34%
26%
23%
17%
35%
30%
20%
15%
Environmental Benefits.
Unit Cost.
Ease of Implementation.
All three respondent groups indicated the same order of priorities for decision-making. For example,
Reliability was consistently assigned the highest weight, indicating the critical significance of providing
reliable water access for the City and community. Environmental Benefits are also given considerable
weight, reflecting the importance of sustainability and social responsibility in decision-making processes.
Similarly, Unit Cost and Ease of Implementation received lower weights by all respondent groups, with
Ease of Implementation getting the lowest relative importance weight in all the polls. This suggests that
while they are still important considerations, they are not considered as important as Reliability or
Environmental Benefits in determining the overall scoring or priority of an option. The selected weight
shown in the far-right column of Table 4.6 is used in the portfolio evaluation presented in Chapter 5.
Additionally, Chapter 5 presents a separate sensitivity analysis showing how portfolio recommendations
would change with different criteria weighting profiles.
4.4 Option Evaluation
This section describes how the option evaluation scores were assigned or calculated for each criterion for
each of the nine (9) options that passed the screening process described in Chapter 3 and that are
considered for the portfolio evaluation in this OWP. It should be noted that each of the quantitative
criteria scores (Reliability, Unit Cost, Reliance on the Tuolumne River) are shown with two significant
figures as these are calculated values, while qualitative criteria are scored using whole integers.
4.4.1 RWS Supply
The evaluation of the RWS Supply option against the evaluation criteria is summarized in Table 4.7. While
RWS Supply excels in some respects, such as its relatively low unit cost and very easy implementation, it
falls short in other respects. Given that RWS Supply is limited and is a Tuolumne River supply, RWS Supply
cannot mitigate shortages in RWS, nor reduce Palo Alto's reliance on supplies from the Tuolumne River.
Additionally, the RWS’s utilization of freshwater from an existing source is not considered efficient as
defined in this OWP, and it has a moderately negative impact on ecosystems and watershed health
through its reliance on the Tuolumne River. As shown in Table 4.7, the combined, unweighted score of the
RWS Supply option is 25.1 out of a maximum score of 40.
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Table 4.7 RWS Supply Evaluation Results
ScoreEvaluation Criteria Score Explanation
Reliability
Unit Cost
1.0 This option inherently does not mitigate shortages in RWS supplies.
4.1 RWS Supply has an estimated unit cost of $2,210/af in 2023 dollars and
$4,088/af in 2045. This is relatively low compared to other options.
Environmental Benefits 5.0 Combined score of 3 sub-criteria (in italics below)
Reliance on Tuolumne 1 RWS Supply does not reduce Palo Alto’s dependence on supplies from the
Tuolumne River.
Efficient Use of Water
Ecological Benefits
2 RWS Supply is not considered to be an efficient use of water in the context of
this OWP because it uses freshwater from an existing source of water supply
and does not have any inherent water use efficiency or reuse.
2 Per the City’s stance on the Bay-Delta Plan implementation, it is acknowledged
that RWS Supply has a moderately negative impact on ecosystems and
watershed health by removing water from the Tuolumne River and Bay Delta
system for municipal use.
Ease of Implementation
Implementation Timeline
Operational Complexity
15.0 Combined score of 3 sub-criteria (in italics below)
5
5
RWS Supply is the City’s existing supply, so it is already implemented.
RWS Supply is the City’s existing supply, so operation is very straightforward,
with no additional staff or training needed.
Public Acceptance 5 RWS Supply is perceived as highly favorable by the general public, given its
high quality and good aesthetic qualities.
Total Unweighted Score 25.1 Out of a maximum score of 40.
4.4.2 Enhanced Water Conservation – Phase 1
Table 4.8 shows the evaluation of the Enhanced Water Conservation – Phase 1 option against the
evaluation criteria. This option performs well in terms of Unit Cost, being the most cost-effective option
among available choices, and is deemed very efficient in its water usage, reducing overall water
consumption. Though it has moderate ecosystem benefits and reduces energy usage through reducing
water use, its relatively low yield (water usage offset) does not significantly mitigate shortages associated
with the RWS Supply or reduce reliance on Tuolumne River supplies. Enhanced Water Conservation
generally scores well for Ease of Implementation, relative to the more infrastructure-intensive options.
Note that there is no expected change in dry year yield relative to normal year yield; although dry
conditions can mean more water use, water conservation can be effective in any climate conditions.
Customers may conserve more during dry years in response to public awareness and/or water
conservation mandates during drought conditions. As shown in Table 4.8, the combined, unweighted
score of the Enhanced Water Conservation – Phase 1 option is 28.2 out of a maximum score of 40. This is
higher than the total score of RWS Supply.
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Table 4.8 Enhanced Conservation – Phase 1 Evaluation Results
Evaluation Criteria Score
1.6
Score Explanation
Reliability
Unit Cost
This option has a relatively low dry year usage offset yield of 724 afy in 2045.
5.0 This option has an estimated unit cost of $312/af in 2023 dollars and $690/af in
year 2045. It receives a score of 5 as this option has the lowest unit cost of all
options considered. This unit cost reflects the cost to Palo Alto not including any
additional cost funded by Valley Water. Additionally, the cost includes Palo Alto
staff time for enforcement.
Environmental Benefits 10.6 Combined score of 3 sub-criteria (in italics below)
Reliance on Tuolumne 1.6 This option has a relatively low normal year usage offset yield of 724 afy in 2045
and thus does not significantly decrease Palo Alto's dependence on supplies
from the Tuolumne River.
Efficient Use of Water
Ecological Benefits
5
4
This option is considered very efficient in its use of water as it promotes water
use efficiency and reduces overall water use.
Through its reduction in overall water use, this option moderately benefits
ecosystems and watershed health and reduces energy use.
Ease of Implementation 11.0 Combined score of 3 sub-criteria (in italics below)
Implementation Timeline 3 Implementing different measures within this option have different timelines with
some options, such as implementing a permanent 3-day watering week, allowing
for almost immediate implementation while others, such as banning non-
functional turf for CII properties or for new developments, could take longer to
implement. Thus, this option received a score of 3 to reflect that 2 to 5 years
would be needed to capture significant savings from this option.
Operational Complexity
Public Acceptance
4
4
This option is somewhat straightforward with minor training and some additional
conservation staff (approximately 1.7 FTE) needed.
This option is likely to be favorable to the public and other stakeholders as the
community generally supports increased water use efficiency.
Total Unweighted Score 28.2 Out of a maximum score of 40.
4.4.3 Enhanced Water Conservation – Phase 2
The evaluation of the Enhanced Water Conservation – Phase 2 option against the evaluation criteria is
shown in Table 4.9. This option excels in terms of efficient water usage, contributing significantly to water
conservation efforts, and offers moderate Ecological Benefits and reduces energy use through reducing
overall water use. It is also a relatively cost-effective option compared to other more infrastructure-based
options. However, it is relatively low yield (water usage offset) does not significantly mitigate shortages
associated with RWS supplies or reduce reliance on Tuolumne River supplies. This option scores
moderately well considering Ease of Implementation, with a moderate implementation timeline of 5 to
10 years and typical Operational Complexity requiring some additional staff and training, as well as
anticipated mixed opinions in terms of Public Acceptance.
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Overall, while offering notable benefits in Unit Cost and Environmental Benefits criteria, this option’s
relatively low usage offset yield results in lower scores for the Reliability criteria and Reliance on Tuolumne
sub-criteria. As shown in Table 4.9, the combined, unweighted score of this option is 24.0 out of a
maximum score of 40.
Table 4.9 Enhanced Conservation – Phase 2 Evaluation Results
ScoreEvaluation Criteria Score Explanation
Reliability
Unit Cost
1.5 This option has a relatively low dry year usage offset yield of 618 afy in 2045.
4.0 This option has an estimated unit cost of $1,939/af in 2023 dollars and $4,313/af
in year 2045, which is relatively low compared to the other options. This unit cost
reflects the cost to Palo Alto not including any additional cost funded by Valley
Water. Additionally, the cost includes Palo Alto staff time for enforcement.
Environmental Benefits 10.5 Combined score of 3 sub-criteria (in italics below)
Reliance on Tuolumne 1.5 This option has a relatively low normal year usage offset yield of 618 afy in 2045
and thus does not significantly decrease Palo Alto's dependence on supplies from
the Tuolumne River.
Efficient Use of Water
Ecological Benefits
5
4
This option is considered very efficient in its use of water as it promotes water use
efficiency and reduces overall water use.
Through its reduction in overall water use, this option moderately benefits
ecosystems and watershed health and reduces energy use.
Ease of Implementation 8.0 Combined score of 3 sub-criteria (in italics below)
Implementation Timeline 2 The measures included in this option are expected to take up to 10 years to reach
saturation, such as the high-efficiency toilet (HET) replacement program for
commercial properties. Some of the other Best Management Practices included in
this option, such as City landscaping support for turf replacement are not expected
to reach saturation within the planning horizon of this Plan. This option received a
score of 2 to reflect that 5 to 10 years would be needed to capture significant
savings from this option.
Operational Complexity
Public Acceptance
3
3
This option is moderately straightforward with some training and some additional
conservation staff (approximately 2.2 FTE) needed to enforce measures,
particularly limiting lawns for residential properties upon resale.
Mixed opinions are expected, given the range of measures included in this option.
While HET replacement for commercial properties and City landscaping support
for turf replacement are both expected to be received neutrally or favorably by the
public, there may be some pushback or resistance to implementing lawn
limitations for residential properties upon resale.
Total Unweighted Score 24.0 Out of a maximum score of 40.
4.4.4 Groundwater
Table 4.10 shows the evaluation of the Groundwater option against the evaluation criteria. With a dry year
yield of 1,800 afy, assuming a cutback of 20 percent on groundwater pumping during a dry year, and a
normal year yield of 2,250 afy, this option could moderately help mitigate shortages associated with RWS
supplies and reduce dependence on Tuolumne River supplies. The normal year yield for this option is
based upon the Northwest County Recycled Water Strategic Plan analysis of the groundwater that could be
pumped without negative impacts on sustainably managed groundwater levels (Todd Groundwater,
2018).
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The dry year yield for this option is expected to be approximately 20 percent lower than the normal year
yield, as it is expected that in severe drought conditions, Valley Water, who manages sustainable
groundwater levels in the county through active management of the basins, would enact mandatory water
use reduction measures that may affect pumping from the Santa Clara Valley groundwater basin. While
Valley Water has not implemented mandatory groundwater pumping restrictions during past droughts,
and the development of such policies would include a public process, Valley Water has asked for
voluntary and/ or mandatory reductions of 20 percent or more in past droughts. Valley Water’s level of
service goal is 80 percent of water supply in droughts however, Valley Water did call for a 30 percent
reduction in 2015. A 20 percent estimate was assumed to represent a moderate, but not major, reduction
of yield in dry years.
Table 4.10 Groundwater Evaluation Results
Evaluation Criteria
Reliability
Score Score Explanation
2.6 With a dry year yield of 1,800 afy, this option falls slightly lower than the middle of
the range of dry year yields of other options.
Unit Cost 2.0 This option has an estimated unit cost of $4,663/af in 2023 dollars and $12,045/af
in year 2045, which is relatively high compared to other options. These unit costs
include the groundwater production charge, O&M costs, and capital costs.
Environmental Benefits 7.7 Combined score of 3 sub-criteria (in italics below)
Reliance on Tuolumne 2.7 With a normal year yield of 2,250 afy, this option moderately reduces Palo Alto's
dependence on supplies from the Tuolumne River. Note that Valley Water
manages the groundwater basin with local managed supplies and natural
recharge as well as imported water that is not from the Tuolumne River but is
from the Delta.
Efficient Use of Water
Ecological Benefits
2
3
This option is not considered to be an efficient use of water because it uses
freshwater from an existing source of water supply.
This option has limited benefits or negative impacts on ecosystems and
watershed health and would require minimal energy for operation. The RO
Concentrate disposal will create some changes to the wastewater discharge.
Ease of Implementation 9.0 Combined score of 3 sub-criteria (in italics below)
Implementation Timeline 3 Many studies have been completed already. Permitting efforts would be needed,
as well as design and construction of additional small treatment and
infrastructure. This option has a typical implementation timeline of 2-5 years
Operational Complexity
Public Acceptance
3
3
This option would require some additional staff and training.
Neutral or mixed opinions are expected, with some in support and others in
opposition given some support for increased local reliability and some opposition
to groundwater use due to perceived quality differences with RWS water supply.
Total Unweighted Score 21.3 Out of a maximum score of 40.
The Unit Cost for this option is the second highest of all options that passed the screening criteria,
resulting in a relatively low score for this criterion. The high overall unit cost is driven by the high
groundwater pumping charge (GPC) levied by Valley Water, which is expected to increase by almost
four-fold over the OWP planning horizon and also by the need to build treatment facilities, including RO
system and RO concentrate disposal pipeline approximately 2 miles from the wells to the City’s Bay outfall
pipeline. The OWP assumes treatment is needed to bring the aesthetics (taste and odor) of the water to a
comparable quality to the Regional Water System water that Palo Alto customers are accustomed to. The
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Environmental Benefits and Ease of Implementation criteria score moderately well for this option, as it is
not expected to have significant positive or negative environmental impacts except for the positive
ecosystem benefits associated with the reduction of flows from the Tuolumne River. The implementation
of this option is relatively straightforward compared to other options.
Overall, Groundwater received moderate scores across most criteria but low scores for Unit Cost and
Efficient Use of Water. As shown in Table 4.10, the combined, unweighted score of the Groundwater
option is 21.3 out of a maximum score of 40.
4.4.5 DPR with Palo Alto Facility
The evaluation of the DPR with Palo Alto Facility option against the evaluation criteria is shown in
Table 4.11. With a dry year yield of 4,487 afy and a normal year yield of 4,723 afy, this option could
mitigate shortages associated with the RWS and reduce dependence on Tuolumne River supplies. The dry
year yield for this option is expected to be approximately 5 percent lower than the normal year yield, as
indoor conservation during dry years may lead to lower flows to the RWQCP and thus result in less inflow
available for the City’s DPR treatment facility. This slight reduction in dry year yield reflects the fact that
potable reuse is generally considered to be a drought-resistant supply. Note that this option would not be
feasible in the scenario where Valley Water exercises its option to transfer a portion of RWQCP effluent to
Valley Water, as there would not be sufficient effluent remaining to support a City-owned DPR facility.
Thus, the evaluation described in this section is only valid under the assumption that Valley Water does
not exercise its option to Transfer a portion of RWQCP effluent to Valley Water, meaning that in the
Evaluation Tool, the Valley Water transfer is inactive (selected as “no”).
The Unit Cost for this option falls near the middle of all options considered in this OWP, resulting in a
moderate Unit Cost criteria score. The Environmental Benefits criteria category is mixed, with the Palo Alto
DPR Facility receiving high scores for Reduced Reliance on the Tuolumne River and Efficient Use of Water
sub-criteria; however, Ecological Benefits receive a lower overall score due to its energy usage for typical
DPR treatment technologies (Reverse Osmosis or RO) and RO concentrate disposal considerations. DPR
also has a long implementation timeline that is likely to require 10 years or more due to permitting and
community engagement needs, making it less feasible in the short term.
Moreover, it is operationally complex, requiring additional training and staff. In terms of Public
Acceptance, it is anticipated that this option could encounter more opposition from the public and
stakeholders compared to other options; however, the reliability benefits can also make this more
favorable for others. Although DPR is new for California, the public can be educated about the successful
implementation in other places like Texas (over 11 years) and internationally. DPR is under consideration
by multiple agencies across the state, including the SFPUC, in their Alternative Water Supply Plan. Overall,
Palo Alto DPR addresses Reliability concerns and reduces Reliance on Tuolumne River, but it would be
relatively complex and difficult to implement.
As shown in Table 4.11, the combined, unweighted score of the DPR with Palo Alto Facility option is 22.9
out of a maximum score of 40.
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Table 4.11 DPR with Palo Alto Facility Evaluation Results
Evaluation Criteria Score
Reliability
Score Explanation
4.9 With a dry year yield of 4,487 afy (assuming a 5% cutback due to declining
wastewater flows during dry years), this option has one of the highest dry year
yields of all the options considered and would significantly benefit the City
during dry years where RWS Supply is limited.
Unit Cost 3.4 This option has an estimated unit cost of $3,594/af in 2023 dollars and
$6,836/af in year 2045, generally in the middle of other option unit costs.
Environmental Benefits 10.7 Combined score of 3 sub-criteria (in italics below)
Reliance on Tuolumne 4.7 With a normal year yield of 4,723 afy, this option significantly reduces Palo
Alto's dependence on supplies from the Tuolumne River.
Efficient Use of Water
Ecological Benefits
4 This option scores well as an efficient use of water as it uses recycled water
that would otherwise be discharged as treated effluent.
2 This option has a moderately negative impact on ecosystems and watershed
health due to the RO concentrate discharge and increased energy use
associated with RO treatment. However, reduction of flows from the Tuolumne
River provides positive ecosystem benefits. Additionally, this option would
reduce treated wastewater discharge which would allow a small, localized area
to convert back to its historic salt marsh state, which is a benefit.
Ease of Implementation 4.0 Combined score of 3 sub-criteria (in italics below)
Implementation Timeline 1 Given the recent approval of statewide DPR regulations, and additional
administrative process at the state, and the fact that this option has not yet
been implemented in California, additional pilot testing would be needed for this
option compared to others. Lengthy permitting and CEQA processes are also
expected, giving this option a long implementation timeline of 10 years or more.
Operational Complexity
Public Acceptance
1
2
This option is very complicated to operate relative to other non-DPR options, as
the AWPF would require continuous process monitoring, 24/7 operation, an
enhanced source control program, and significant staff training.
This option is expected to have more opposition from the public than other
non-DPR options due to general negative public perception around DPR.
Extensive stakeholder engagement would likely be required to garner public
support for this option.
Total Unweighted Score 22.9 Out of a maximum score of 40.
4.4.6 DPR with Regional Facility
The evaluation of the DPR with the Regional Facility option against the evaluation criteria is shown in
Table 4.12. With a dry year yield of 1,681 afy and a normal year yield of 1,769 afy, this option could
moderately help mitigate shortages associated with RWS supplies and reduce dependence on Tuolumne
River supplies. The dry year yield for this option is expected to be approximately 5 percent lower than the
normal year yield as indoor conservation during dry years may lead to lower flows to the RWQCP, and
thus result in less inflow available for the DPR treatment facility. This slight reduction in dry year yield
reflects the fact that potable reuse is generally considered to be a drought-resistant supply. Note that this
option would only be feasible in the scenario where Valley Water constructs a DPR Regional Facility in
Palo Alto. Thus, the evaluation described in this section is only valid under the assumption that the Valley
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Water Transfer option is exercised, meaning that in the Evaluation Tool, the Valley Water transfer is active
(selected as “yes”).
Table 4.12 DPR with Regional Facility Evaluation Results
Evaluation Criteria
Reliability
Score Score Explanation
2.5 With a dry year yield of 1,681 afy, this option would moderately benefit the City
during dry years where RWS Supply is limited.
Unit Cost 2.9 This option has an estimated unit cost of $4,024/af in 2023 dollars and $8,689/af
in 2045, which is moderately less cost-efficient compared to other options.
Environmental Benefits 8.4 Combined score of 3 sub-criteria (in italics below)
Reliance on Tuolumne 2.4 With a normal year yield of 1,769 afy, this option moderately reduces Palo Alto's
dependence on supplies from the Tuolumne River.
Efficient Use of Water
Ecological Benefits
4
2
This option scores as an efficient use of water as it uses recycled water that
would otherwise be discharged as treated effluent.
This option has a moderately negative impact on ecosystems and watershed
health due to the RO concentrate discharge and increased energy use
associated with RO treatment. However, reduction of flows from the Tuolumne
River provides positive ecosystem benefits. Additionally, this option would reduce
treated wastewater discharge which would allow a small, localized area to
convert back to its historic salt marsh state, which is a benefit.
Ease of Implementation 8.0 Combined score of 3 sub-criteria (in italics below)
Implementation Timeline 1 Given the recent approval of statewide DPR regulations and the fact that this
option has not yet been implemented in California, additional pilot testing would
be needed for this option compared to others. Lengthy permitting and CEQA
processes are also expected, giving this option a long implementation timeline of
10 years or more. Additionally, the development of this option is outside of Palo
Alto’s control.
Operational Complexity 5
2
Although operating an AWPF is generally complex, Valley Water would be
operating the facility for this option. Palo Alto would receive potable water into its
system in a similar manner as Palo Alto receives RWS Supply. Thus, operation
from the City’s perspective would be more straightforward relative to the Palo Alto
DPR option.
Public Acceptance This option is expected to have more opposition from the public than other
non-DPR options due to general negative public perception around DPR.
Extensive stakeholder engagement would be required to garner public support for
this option.
Total Unweighted Score 21.7 Out of a maximum score of 40.
The Unit Cost for this option falls near the middle of all options considered in this OWP, resulting in a
moderate Unit Cost criteria score. The Environmental Benefits criteria category is mixed, with the DPR with
Regional Facility receiving a high score for the Efficient Use of Water criteria; however, Ecological Benefits
receive a lower overall score due to its energy usage for typical DPR treatment technologies (Reverse
Osmosis), and RO concentrate disposal considerations. Nevertheless, DPR with Regional Facility has some
positive ecosystem benefits from reduced flows from the Tuolumne River. DPR has a long implementation
timeline likely to extend 10 years or more due to permitting and community engagement needs, making
it less feasible in the short term, and it is less favorable due to anticipated public concerns compared to
other non-DPR options. However, in contrast to the DPR with Palo Alto Facility option, the Operational
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Complexity of the DPR with Regional Facility option would be straightforward for Palo Alto, as the City
would receive purified water from Valley Water and not play a role in operating the Regional DPR facility.
However, Palo Alto and Valley Water would work in close partnership.
Overall, DPR with Regional Facility scores moderately well across most criteria, with high scores for
Efficient Use of Water and Operational Complexity and lower scores when considering Ecological Benefits,
Implementation Timeline, and Public Acceptance. As shown in Table 4.12, the combined, unweighted
score of the Regional DPR Facility option is 21.7 out of a maximum score of 40.
4.4.7 DPR with Palo Alto Facility and SSRF
The evaluation of the DPR with Palo Alto Facility and SSRF option against the evaluation criteria is
summarized in Table 4.13.
Table 4.13 DPR with Palo Alto Facility and SSRF Evaluation Results
Evaluation Criteria
Reliability
Score
1.5
Score Explanation
With a dry year yield of 599 afy, this option yield limits the benefit to the City’s dry
year water supply where RWS Supply is limited.
Unit Cost 1 This option has a unit cost of $8,897/af in 2023 dollars and $15,597/af for year
2045, which is highest among all of the options that passed through the
pre-screening and screening steps.
Environmental Benefits 7.5 Combined score of 3 sub-criteria (in italics below)
Reliance on Tuolumne 1.5 With a normal year yield of 630 afy, this option yield provides limited benefit to
Palo Alto's normal year dependence on supplies from the Tuolumne River.
Efficient Use of Water
Ecological Benefits
4
2
This option scores as an efficient use of water as it uses recycled water that
would otherwise be discharged as treated effluent.
This option has a moderately negative impact on ecosystems and watershed
health due to the RO concentrate discharge and increased energy use associated
with RO treatment. However, the reduction of flows from the Tuolumne River
provides positive ecosystem benefits. Additionally, this option would reduce
treated wastewater discharge which would allow a small, localized area to convert
back to its historic salt marsh state, which is a benefit.
Ease of Implementation 4.0 Combined score of 3 sub-criteria (in italics below)
Implementation Timeline 1 Given the recent approval of statewide DPR regulations and the fact that this
option has not yet been implemented in California, additional pilot testing would
be needed for this supply option compared to other non-DPR options. Lengthy
permitting and CEQA processes are also expected, given that this option has a
long implementation timeline of 10 years or more.
Operational Complexity
Public Acceptance
1
2
This option is very complicated to operate relative to other non-DPR options, as
the AWPF and SSRF would require continuous process monitoring, 24/7
operation, an enhanced source control program, and significant staff training.
This option is expected to have more opposition from the public than other
non-DPR options due to general negative public perception around DPR.
Extensive stakeholder engagement would be required to garner public support.
Total Unweighted Score 14.0 Out of a maximum score of 40.
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With a dry year yield of 599 afy and a normal year yield of 630 afy, this option scores relatively lower on
the Reliability and Reliance on Tuolumne River evaluation criteria and sub-criteria compared to options
with a higher yield. The dry year yield for this option is assumed to be approximately 5 percent lower than
the normal year yield as indoor conservation during dry years may lead to lower flows to the RWQCP, and
thus result in less inflow available for the DPR treatment facility. This slight reduction in dry year yield
reflects the fact that potable reuse is generally considered to be a drought-resistant supply.
The Unit Cost for this option is the highest of all of the options that passed through the pre-screening and
screening steps, resulting in the lowest Unit Cost score. The Unit Cost for this option is very high due to
the capital cost associated with constructing a DPR facility while receiving very low yield as limited by Palo
Alto’s portion of the SSRF capacity. The Environmental Benefits criteria category is mixed, with the DPR
with Palo Alto Facility and SSRF receiving a high score in the Efficient Use of Water criteria but a lower
score when considering Ecological Benefits due to its energy usage for typical DPR treatment
technologies (Reverse Osmosis) and RO concentrate disposal considerations. Nevertheless, Palo Alto DPR
Facility with SSRF has some positive ecosystem benefits from reduction of flows from the Tuolumne River.
DPR has a long implementation timeline that is likely to require 10 years or more due to permitting and
community engagement needs, making it less feasible in the short term. Moreover, it is operationally
complex, requiring additional training and staff. In terms of Public Acceptance, it is less favorable and
expected to encounter more opposition from the public and stakeholders compared to other options.
Overall, DPR with Palo Alto Facility and SSRF scores low across many criteria due to its low yield, high cost,
and significant Operational Complexity. As shown in Table 4.13, the combined, unweighted score of the
Palo Alto DPR Facility with the SSRF option is 14.0 out of a maximum score of 40. This is the lowest total
unweighted score of all nine (9) options that passed the screening criteria process described in Chapter 3.
4.4.8 IPR with Groundwater Injection
The evaluation of the IPR via groundwater injection wells option against the evaluation criteria is shown in
Table 4.14. With a dry year yield of 4,893 afy and a normal year yield of 5,150 afy, this option could
mitigate shortages associated with RWS supplies and reduce dependence on Tuolumne River supplies.
The OWP assumes the dry year yield for this option is approximately 10 percent lower than the normal
year yield based on the fact that this option supplies groundwater and also relies on recycled water for
groundwater replenishment. During a severe drought, Valley Water may call for voluntary or mandatory
water use reductions. Recycled water is assumed to be reduced by 5 percent during dry years. Note that
this option would not be feasible in the scenario where Valley Water exercises its option to transfer a
portion of RWQCP effluent to Valley Water, as there would not be sufficient effluent remaining to support
a City-owned IPR facility. Thus, the evaluation described in this section is only valid if Valley Water does
not exercise its option to transfer a portion of RWQCP effluent, meaning that in the Evaluation Tool, the
Valley Water transfer is inactive (selected as “no”).
The Unit Cost for this option falls in the middle to upper end, resulting in a moderately low Unit Cost
criteria score. The cost is higher than other large potable reuse options largely due to the high cost of
pumping groundwater due to the expected increases in the GPC levied by Valley Water. The
Environmental Benefits criteria category is mixed, with IPR receiving high scores for Reduced Reliance on
the Tuolumne River and Efficient Use of Water criteria but a lower score when considering Ecological
Benefits due to its energy usage for typical IPR treatment technologies (Reverse Osmosis) and RO
concentrate disposal considerations. Nevertheless, the option has some positive ecosystem benefits
CITY OF PALO ALTOONE WATER PLAN 4-18
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associated with reduction of flows from the Tuolumne River. IPR has a moderately long implementation
timeline of 5 to 10 years and is operationally complex, requiring additional training and staff. In terms of
Public Acceptance, IPR with Groundwater Injection is expected to receive a mixed reception as IPR is
generally accepted by the public but there may be pushback to using a groundwater-based source due to
perceived water quality differences with the existing RWS Supply.
Overall, IPR addresses Reliability concerns and reduces Reliance on Tuolumne River, but it would be
relatively expensive and difficult to implement. As shown in Table 4.14, the combined, unweighted
score of the IPR with groundwater injection option is 24.4 out of a maximum score of 40. This is the
third highest total unweighted score of all nine (9) options that passed the screening criteria process (only
RWS Supply and Enhanced Water Conservation Phase 1 score higher).
Table 4.14 IPR with Groundwater Injection Evaluation Results
Evaluation Criteria
Reliability
Score Score Explanation
5.0 With a dry year yield of 4,893 afy, this option has the highest dry year yield of all
the options considered and would significantly benefit the City during dry years
where RWS supply is limited.
Unit Cost 2.4 This option has an estimated unit cost of $4,992/af in 2023 dollars and
$10,267/af for in 2045, which is moderately less cost-efficient compared to other
options.
Environmental Benefits 10.0 Combined score of 3 sub-criteria (in italics below)
Reliance on Tuolumne 5.0 With a normal year yield of 5,150 afy, this option significantly reduces Palo Alto's
dependence on supplies from the Tuolumne River.
Efficient Use of Water
Ecological Benefits
3 IPR is considered neutral in this criterion as it uses a combination of groundwater
and injected recycled water.
2 This option has a moderately negative impact on ecosystems and watershed
health due to the RO concentrate discharge and increased energy use
associated with RO treatment. However, reduction of flows from the Tuolumne
River provides positive ecosystem benefits. Additionally, this option would reduce
treated wastewater discharge which would allow a small, localized area to
convert back to its historic salt marsh state, which is a benefit.
Ease of Implementation 7.0 Combined score of 3 sub-criteria (in italics below)
Implementation Timeline 2 While IPR has been extensively implemented in California, additional studies and
preparation would be needed to implement this option, and design, CEQA, and
permitting would take several years. The City could likely implement this option in
5-10 years.
Operational Complexity 2 This option is fairly complicated to operate relative to other options, as the AWPF
would require continuous process monitoring, 24/7 operation, an enhanced
source control program, and significant staff training. Operation of the injection
wells would not add significant operational complexity compared to using the
wells for extraction. Overall, this option would likely require less extensive
operational requirements than DPR, given the use of groundwater as an
environmental buffer.
Public Acceptance 3 Mixed opinions are expected, as IPR is more generally publicly accepted than
DPR, but there may still be resistance to using groundwater-based IPR due to
perceived water quality differences with RWS Supply.
Total Unweighted Score 24.4 Out of a maximum score of 40.
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4.4.9 Bay Water Desalination
Table 4.15 shows the evaluation of the Bay Water Desalination option against the evaluation criteria. With
a dry year and normal year yield of 4,480 afy, this drought-proof option could mitigate shortages
associated with the RWS and reduce dependence on Tuolumne River supplies. Despite its high yield, Bay
Water Desalination has a very high Unit Cost compared to other options, making it challenging to
implement cost-effectively. Moreover, Bay Water Desalination is expected to have negative impacts on
ecosystems and watershed health related to the intake and RO concentrate disposal, as well as a notable
increase in energy use. It is likely to face some public opposition due to these concerns. Bay Water
Desalination’s long implementation timeline exceeding 10 years and high Operational Complexity
requiring additional training and staff further add to implementation challenges.
Overall, while Bay Water Desalination offers benefits in addressing water shortages and reducing Reliance
on Tuolumne River, it faces significant challenges in terms of cost, ecological impact, and implementation
hurdles. As shown in Table 4.15, the combined, unweighted score of the Bay Water Desalination option is
20.4 out of a maximum score of 40.
Table 4.15 Bay Water Desalination Evaluation Results
Evaluation Criteria
Reliability
Score Score Explanation
4.9 With a dry year yield of 4,480 afy, this option has one of the highest dry year
yields of all the options considered and would benefit the City during dry years
where RWS Supply is limited.
Unit Cost 2.0 This option has an estimated unit cost of $6,768/af in 2023 dollars and $11,815/af
in year 2045, which is higher than most other options.
Environmental Benefits 8.5 Combined score of 3 sub-criteria (in italics below)
Reliance on Tuolumne 4.5 With a normal year yield of 4,480 afy, this option reduces Palo Alto's dependence
on supplies from the Tuolumne River.
Efficient Use of Water
Ecological Benefits
3
1
Bay Water Desalination is scored neutral in this criterion as it uses water from a
non-potable (i.e., saline) water source.
This option may have a negative impact on ecosystems and watershed health
due to the RO concentrate discharge and increased energy use associated with
RO treatment, as well as concerns about ecosystem damage around the intake
structure. However, reduction of flows from the Tuolumne River provides positive
ecosystem benefits.
Ease of Implementation 5.0 Combined score of 3 sub-criteria (in italics below)
Implementation Timeline 1 More in-depth feasibility studies and design processes would be needed for this
option than others. Challenging and lengthy permitting and CEQA processes are
also expected, giving this option a long implementation timeline of 10 years or
more.
Operational Complexity
Public Acceptance
1
3
This option is very complicated to operate relative to other options, as the
desalination facility would require continuous process monitoring, 24/7 operation,
an enhanced source control program, and significant staff training.
Mixed opinions are expected, with some in support of this option as a
drought-proof and self-sufficient supply and with others in opposition due to
environmental concerns.
Total Unweighted Score 20.4 Out of a maximum score of 40.
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4.5 Option Evaluation Summary
The evaluation criteria scores for each option are summarized in Table 4.17. Both the unweighted and
weighted scores are presented. An example of how the weighted scores are calculated from the raw
scores is shown in Table 4.16.
Table 4.16 Example of Weighted Score Calculation
Raw Score
(A)
Criteria Weight
(B)
Weighted Score
(A x B)Evaluation Criteria
Reliability 5.0
2.4
10.0
3.0
2.0
5.0
7.0
2.0
2.0
3.0
24.4
35%
20%
30%
10%
10%
10%
15%
5%
1.8
0.5
1.0
0.3
0.2
0.5
0.4
0.1
0.1
0.2
3.6
Unit Cost
Environmental Benefits
Reliance on Tuolumne
Efficient Use of Water
Ecological Benefits
Ease of Implementation
Implementation Timeline
Operational Complexity
Public Acceptance
5%
5%
Total Unweighted Score 100%
Notes:
Example reflects the Raw and Weighted scores for the IPR with Groundwater Injection option.
As shown in Table 4.17, the new options (excluding RWS Supply), that score the highest without applying
any weighting factors, meaning that criteria and sub-criteria weight equally, are in order of decreasing
total score:
.
.
.
Enhanced Water Conservation – Phase 1 (total score: 28.2).
IPR with Groundwater Injection (total score: 24.4).
Enhanced Water Conservation – Phase 2 (total score: 24.0).
When considering all criteria and sub-criteria with their relative weighting factors developed with input
from both City staff and stakeholders as summarized in Table 4.6, the following new options score the
highest in order of decreasing score:
.
.
.
DPR with Palo Alto Facility (total score: 3.7).
IPR with Groundwater Injection (total score: 3.6).
Enhanced Water Conservation – Phase 1 and Bay Water Desalination (both total score: 3.2).
It can be concluded that both Enhanced Water Conservation – Phase 1 and IPR with Groundwater
Injection score in the top three (3) options, with and without the use of the relative weighting factors. This
means that these options are robust solutions as these are not very sensitive to changes in the weighting
factor percentages as these options score each well in multiple criteria. Moreover, it can be concluded
that the DPR with Palo Alto Facility and SSRF option scores the lowest with and without weighting factors,
due to multiple minimal scores, including Unit Cost, Reliability, Reliance on the Tuolumne River,
Implementation Timeline, and Operational Complexity.
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Table 4.17 Option Evaluation Results Summary
Environmental Benefits Ease of Implementation
Total
Unweighted
Score(3)
Total
Weighted
Score(3,4)
Reduced
Tuolumne
River
Unit
Cost Efficient
Use of
Water
Option Reliability Ecological Implementation Operational Public
Benefit Timeline Complexity Acceptance
Reliance
Criteria Weight 35%
1.0
1.6
1.5
2.6
4.9
2.5
1.5
5.0
4.9
20%
4.1
5.0
4.0
2.0
3.4
2.9
1.0
2.4
2.0
10%
1.0
1.6
1.5
2.7
4.7
2.4
1.5
5.0
4.5
10%
2
10%
2
5%
5
5%
5
5%
5
n/a n/a
2.4
3.2
2.8
2.5
3.7
2.7
1.7
3.6
3.2
RWS Supply 25.1
28.2
24.0
21.3
22.9
21.7
14.0
24.4
20.4
Enhanced Conservation – Phase 1
Enhanced Conservation – Phase 2
Groundwater
5 4 3 4 4
5 4 2 3 3
2 3 3 3 3
DPR with Palo Alto Facility(1)
DPR with Regional Facility(2)
DPR with Palo Alto Facility and SSRF
IPR with Groundwater Injection(1)
4 2 1 1 2
4 2 1 5 2
4 2 1 1 2
3 2 2 2 3
Bay Water Desalination
Notes:
3 1 1 1 3
(1) DPR with Palo Alto Facility and IPR with Groundwater Injection options assume that Valley Water does not exercise its option to transfer a portion of RWQCP effluent
(selected “No” in the Evaluation Tool).
(2) The DPR with Regional Facility option assumes that Valley Water exercises its option to transfer a portion of RWQCP effluent (selected “Yes” in the Evaluation Tool)
(3) Quantitative criteria scores (Reliability, Unit Costs, Reliance on Tuolumne River) are shown with two significant figures as these are calculated values, while qualitative criteria
scores are scored using whole integers.
(4) The three highest scores of new options (excluding the benchmark RWS Supply) are shown in bold font.
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4.5.1 Results without Valley Water Transfer
The weighted-criteria evaluation results without Valley Water exercising the RWQCP effluent transfer
option are shown in Figure 4.2. These results show that DPR with Palo Alto Facility and IPR with
Groundwater Injection are the most favorable options, largely due to their significant contribution to
Reliability (the criterion with the highest weight). Bay Water Desalination and Enhanced Conservation –
Phase 1 also score highly. Meanwhile, DPR with Palo Alto Facility and SSRF, Groundwater, and RWS Supply
all have lower total overall scores. It should be noted that DPR with Regional Facility is not shown in this
scenario, as this option is not feasible without Valley Water exercising the transfer option.
Figure 4.2 Options Evaluation Results without the Valley Water Transfer
4.5.2 Results with Valley Water Transfer
The weighted-criteria evaluation results with Valley Water exercising the RWQCP effluent transfer option
are shown in Figure 4.3. These results show that the highest-scoring options are Bay Water Desalination
and Enhanced Conservation (Phase 1 and Phase 2). DPR Regional Facility, and Groundwater score
moderately well, while RWS Supply and DPR with Palo Alto Facility and SSRF have lower scores overall. It
should be noted that DPR with Palo Alto Facility and IPR with Groundwater Injections are not shown in
this scenario, as these options are not considered feasible with the Valley Water Transfer.
The bar charts also show again visually that the DPR with Palo Alto Facility and SSRF scores the lowest of
all evaluated options. The findings presented in this chapter are used to develop the water supply
portfolios that consider the implementation of different combinations of these options. Chapter 5
presents the portfolios development and evaluation.
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Figure 4.3 Options Evaluation Results with the Valley Water Transfer
It can be observed that the weighted score of Bay Water Desalination (3.2) is higher than the weighted
score of DPR with Regional Facility (2.7). Although the DPR with Regional Facility option scores higher on
cost, efficient use of water, ecological benefit, and operational complexity (combined scores of 1.42
compared to 0.85 for Bay Water Desalination; difference of 0.6), these combined benefits are less than the
benefits of Bay Water Desalination for reliability, reducing reliance on the Tuolumne River, and public
acceptance (combined scores of 1.2 compared to 2.3 for Bay Water Desalination; difference of 1.1).
It should also be noted that Bay Water Desalination scores very high when compared with the other
options, however when compiled in Portfolio C (see Chapter 5), Bay Water Desalination does not score as
high. There are two (2) key explanations that are both related to the two (2) highest weighted criteria,
reliability and cost as follows:
.Reliability Score: This criterion has the highest relative weight of 35 percent. Due to the assumed
yield and drought proof supply of Bay Water, this contributes to the majority of the total option score
as shown in the blue bars of Figure 4.2 and Figure 4.3. Bay Water Desalination scores 175 percent
higher than the average reliability score of all options. However, when combined in the portfolios, the
relative reliability benefit is reduced as all portfolios have a combined high yield and therefore strong
reliability score. This reduces the relative supply reliability benefit in the portfolio evaluation.
.Cost Score: Bay Water Desalination is expensive and thus brings the overall score down compared to
supply options and portfolios with less expensive options. However, in the options comparison, DPR
with Palo Alto Facility and SSRF is actually a more expensive option, limiting influence of this low
score as the scoring of all options is based on the combined range (highest and lowest scores).
Because DPR with Palo Alto Facility and SSRF is not included in any of the portfolios, the high cost of
Bay Water Desalination brings the total cost down more in the portfolio evaluation (Portfolio C cost
score is 29 percent of the average of all portfolios) compared to in the option evaluation (Bay Water
Desalination is 69 percent of the average of all options). This increases the relative impact of the high
cost of Bay Water Desalination in the portfolio evaluation.
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Hence, these two (2) opposing dynamics result in a high score of Bay Water Desalination in the option
evaluation, but a lower score when this option is combined with Enhanced Water Conservation Phase 1
and 2 in the portfolio evaluation which is discussed in Chapter 5.
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CITY OF PALO ALTOONE WATER PLAN 4-26
CHAPTER 5
OCTOBER 2024 / FINAL / CAROLLO
CHAPTER 5 PORTFOLIO DEVELOPMENT AND
EVALUATION
Portfolios in the One Water Plan (OWP) consist of recommended combinations of options. This chapter
describes the portfolio evaluation approach and the portfolio development. The chapter then describes
the data inputs, user selections and outputs of the customized One Water Evaluation Tool (Evaluation
Tool or Tool) and details the results (Tool outputs): Portfolio Supply Summary, Portfolio Cost Estimates
and Portfolio Evaluation. The chapter then outlines a sensitivity analysis of the evaluation criteria
weighting and testing under different scenarios for water demand, RWS Supply shortage and Water
Shortage Contingency Plan shortage stages. The chapter concludes with a summary of the portfolio
evaluation outcomes and that collectively meet the City’s water supply objectives most beneficially. These
combinations of options are flexible and can be updated as future conditions change. Chapter 6 describes
a trigger-based implementation roadmap that provides the basis for the City to implement an adaptable
water supply strategy.
5.1 Portfolio Approach
As described in Chapters 3 and 4, a total of 27 options underwent a preliminary high-level screening
process that resulted in 15 options that were then narrowed down to nine options using three (3)
screening criteria. The nine options that successfully passed this initial screening were then further
developed and subjected to a comprehensive evaluation process using four (4) evaluation criteria as
described in Chapter 4. Table 5.1 below summarizes the evaluation scoring results and normal and dry
year yields of the nine options that passed the screening process (Table 4.16 provides more details on the
option evaluation results and Figure 5.1 summarizes the option evaluation results visually).
Figure 5.1 Option Evaluation Process
Based on the results and discussions with City staff, it was decided to include eight (8) of the nine (9)
options in the seven (7) portfolios that are described in this chapter. The only option that was not
included in any of the portfolios is Direct Potable Reuse (DPR) with a dedicated Palo Alto facility and the
Small Saltwater Removal Facility (SSRF) because it scored significantly lower than all other options, while
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the alternative of Palo Alto DPR (without the SSRF) had the highest weighted score of 3.7 as shown in
Table 5.1.
Table 5.1 Options Evaluation Results Summary
Total
Unweighted
Score(2)
Normal Year Dry Year Dry Year
Yield(3)
(afy)
Weighted
Score(2)
Yield
(afy)
Reduction
(%)(3)Options(1)
DPR with Palo Alto Facility (4)
Palo Alto IPR (4)
3.6
3.6
3.2
3.2
2.8
2.7
2.5
2.4
1.7
22.9
24.4
28.2
20.4
24.0
21.7
21.3
25.1
14.0
4,723
5,150
724
5%
10%
0%
4,487
4,635
724Enhanced Conservation - Phase 1
Bay Water Desalination
Enhanced Conservation - Phase 2
DPR with Regional Facility (4)
Groundwater
4,480
618
0%4,480
6180%
1,769
2,250
12,546
630
5%1,680
1,800
6,273
599
20%
50%
5%
RWS Supply (5)
DPR with Palo Alto Facility and SSRF
Notes:
(1) Options sorted by weighted score in descending order.
(2) See details in Table 4.17.
(3) Dry Year Reduction is a user-input to the Tool.
(4) The Regional DPR option assumes that Valley Water exercises its option to transfer a portion of treated effluent from the
RWQCP (selected “Yes” in the Tool). All other options assume Valley Water does not exercise the effluent transfer option
(selected “No” in the Tool).
(5) Based on estimated supply capacities (and medium growth demand forecast for RWS Supply) in year 2045.
The options evaluation results informed which options the OWP included in the portfolio evaluation. The
option to build a Direct Potable Reuse (DPR) dedicated Palo Alto facility and the Small Salt Removal
Facility (SSRF) was not included in any of the portfolios because it scored significantly lower than all other
options.
5.2 Portfolio Development
As part of this OWP, a total of seven portfolios (A through G) were developed and evaluated. These
portfolios are as follows:
A. Baseline (business as usual relying only on RWS Supply).
B. Enhanced Conservation Phase 1 and 2.
C. Enhanced Conservation Phase 1 and 2 with Bay Water Desalination.
D. Enhanced Conservation Phase 1 and 2 with Groundwater.
E. Enhanced Conservation Phase 1 and 2 with Palo Alto DPR.
F. Enhanced Conservation Phase 1 and 2 with Palo Alto IPR.
G. Enhanced Conservation Phase 1 and 2 with Regional DPR.
The options included in each of these portfolios were based on the option evaluation scoring as described
in Chapter 4 and discussions with City staff. Portfolios A – D can be implemented independent on whether
Valley Water exercises its option to transfer a portion of the treated effluent from the RWQCP. Portfolios E
and F may only be implemented if Valley Water does not exercise the effluent transfer option, while
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Portfolio G may only be implemented if Valley Water does exercise the effluent transfer option. Table 5.2
summarizes the options included in each portfolio.
Table 5.2 Overview of Options included in each Portfolio
Enhanced DPR
withConservation
RWS Phase 1 and Bay Water Ground- Palo Alto Palo Alto Regional
Portfolio Supply Phase 2 Desalination water DPR IPR Facility
A. Baseline X
XB. Enhanced Conservation Phase 1 and 2 X
XC. Enhanced Conservation Phase 1 and 2
with Bay Water Desalination X
X
X
X
X
X
D. Enhanced Conservation Phase 1 and 2
with Groundwater X
X
X
X
X
E. Enhanced Conservation Phase 1 and 2
with Palo Alto DPR X
F. Enhanced Conservation Phase 1 and 2
with Palo Alto IPR X
G. Enhanced Conservation Phase 1 and 2
with Regional DPR X
5.2.1 Portfolio A – Baseline
Portfolio A represents the baseline portfolio which is the City's existing potable water supply from the
RWS and serves as the benchmark for comparing other potential portfolios. This baseline portfolio
represents the status quo of the City’s water supply including already planned projects that are assumed
to be implemented regardless of the findings of this OWP. For the City of Palo Alto this means continued
full reliance on imported water from the RWS, and the planned water conservation programs as outlined
in Appendix B.
5.2.2 Portfolio B – Enhanced Conservation Phase 1 and 2
Portfolio B builds on portfolio A with the addition of Enhanced Conservation Phase 1 and Phase 2, each
encompassing a series of targeted water conservation measures. Enhanced Conservation Phase 1 includes
measures that are easier and cheaper to implement (generally less than $1,000 per acre-foot ($/af), while
Enhanced Conservation Phase 2 consists of more challenging and costly measures, each estimated to
exceed $1,000/af. The projected yields of the different water conservation measures included in Enhanced
Conservation Phase 1 and Phase 2 are summarized in Table 5.3.
With the implementation of Enhanced Conservation Phase 1 (724 afy), and Enhanced Conservation
Phase 2 (618 afy), the offset to RWS Supply water usage would gradually increase to 1,342 afy. Figure 5.2
shows the combined water supply mix under normal demand conditions using the medium demand
forecast. The OWP assumes Enhanced Conservation Phase 1 and Phase 2 save the same amount of water
during normal and dry years.
This portfolio can be implemented whether or not Valley Water exercises the option to transfer a portion
of the treated effluent from the RWQCP.
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Table 5.3 Projected Yield of Enhanced Water Conservation Phase 1 and 2
Enhanced Conservation Phase 1 Measures
Outdoor Irrigation Efficiency for CII Properties
3-Day Watering Week
Yield in 2045 (afy)
229
212
Non-Functional Turf Ban for CII Properties
Lawn Limitation for New Development and Major Retrofits
Low Income Residential HET Replacement Program
Totals
132
139
11
724
Enhanced Conservation Phase 2 Measures
Lawn Limitation for Residential Properties Upon Resale
HET Replacement Program for CII Properties
City Landscaping Support for Turf Replacement
Totals
Yield in 2045 (afy)
446
21
152
619
Total Yield Estimate (Phase 1 and Phase 2)1,342
14,000
12,000
10,000
8,000
6,000
4,000
2,000
0
RWS Supply Enhanced Conservation, Phase 1 Enhanced Conservation, Phase 2
Figure 5.2 Normal Year Supply and Demand Projection for Portfolio B
5.2.3 Portfolio C –Enhanced Conservation Phase 1 and 2 with Bay Water
Desalination
This portfolio builds upon Portfolio B with the addition of Bay Water Desalination using a dedicated
5-mgd Palo Alto facility. The added local supply yield to supplement the existing imported water supply
from the RWS would increase to 4,480 afy from the 5-mgd desalination plant. Together with the usage
offset yield expected by 2045 from Enhanced Conservation Phase 1 (724 afy), and Enhanced Conservation
Phase 2 (618 afy), the portfolio would gradually increase to yield a total of 5,823 afy, to supplement RWS
Supply. The OWP assumes no dry year reduction in supply from the Bay Water Desalination plant.
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Figure 5.3 depicts the estimated sources of supply and assumes the desalination plant comes online in
2035. This portfolio can be implemented with or without the potential Valley Water Transfer.
14,000
12,000
10,000
8,000
6,000
4,000
2,000
0
RWS Supply Bay Water Desalination
Enhanced Conservation, Phase 1 Enhanced Conservation, Phase 2
Figure 5.3 Normal Year Supply and Demand Projection for Portfolio C
Due to the long implementation timeline anticipated to design, permit, and construct a desalination
facility, this portfolio would provide the same added supply reliability as Portfolio B (Enhanced
Conservation only) through year 2035 when the OWP assumes the Bay Water Desalination plant could be
operational.
5.2.4 Portfolio D – Enhanced Conservation Phase 1 and 2 with Groundwater
This portfolio is similar to Portfolio C; however, Bay Water Desalination is replaced with the addition of
groundwater from the conversion of City’s emergency supply wells. As part of this portfolio, the City
would equip two of the existing emergency supply wells with treatment facilities and convert these from
emergency supply to regular potable use. The added local supply yield to supplement the existing RWS
Supply would increase to 2,250 afy. Together with the usage offset yield expected by 2045 from the
implementation of Enhanced Conservation Phase 1 (724 afy), Enhanced Conservation Phase 2 (618 afy),
and groundwater, the portfolio would gradually increase to yield a total of 3,592 afy to supplement RWS
Supply. The OWP assumes a 20 percent groundwater supply reduction during dry years to account for
potential pumping restrictions during drought conditions. Hence, the supplemental yield of the portfolio
under drought conditions would be 3,143 afy.
Figure 5.4 depicts the estimated sources of supply under the medium demand forecast. Palo Alto could
implement this portfolio whether or not Valley Water exercises its option to transfer a portion of the
treated effluent from the RWQCP.
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14,000
12,000
10,000
8,000
6,000
4,000
2,000
0
RWS Supply Groundwater Enhanced Conservation, Phase 1 Enhanced Conservation, Phase 2
Figure 5.4 Normal Year Supply and Demand Projection for Portfolio D
5.2.5 Portfolio E –Enhanced Conservation Phase 1 and 2 with Palo Alto DPR
This portfolio is similar to Portfolio C with the addition of a Palo Alto DPR facility instead of Bay Water
Desalination. The added local supply yield to supplement the existing imported water supply from SFPUC
would increase to 4,723 afy from the 5-mgd DPR facility. Together with the usage offset yield expected by
2045 from the implementation of Enhanced Conservation Phase 1 (724 afy), and Enhanced Conservation
Phase 2 (618 afy), the portfolio would yield a total of 6,065 afy to supplement SFPUC supplies. The net
yield of a 5-mgd DPR facility is assumed to be higher than for a 5-mgd desalination plant due to a higher
advanced water treatment recovery for treating recycled water compared to Bay water. The OWP assumes
a 5 percent dry year reduction to the DPR facility yield to account for lower wastewater flows due to
increased water conservation during drought conditions. Hence, the supplemental yield of the portfolio
under drought conditions would be 5,829 afy. Figure 5.5 depicts the estimated sources of supply under
the medium demand forecast and assumes the DPR plant comes online in 2035.
This portfolio can only be implemented if Valley Water does not exercise the option to transfer a portion
of the treated effluent from the RWQCP because with the transfer there would not be sufficient
wastewater flows for the City to construct a viable DPR facility. Due to the long implementation timeline
anticipated to design, permit, and construct a dedicated DPR facility, this portfolio would provide the
same added supply reliability as Portfolio B (Enhanced Conservation Phase 1 and 2) through year 2035
when the Palo Alto DPR facility is assumed to be operational.
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14,000
12,000
10,000
8,000
6,000
4,000
2,000
0
RWS Supply DPR with Palo Alto Facility
Enhanced Conservation, Phase 2Enhanced Conservation, Phase 1
Figure 5.5 Normal Year Supply and Demand Projection for Portfolio E
5.2.6 Portfolio F – Enhanced Conservation Phase 1 and 2 with IPR
This portfolio is similar to Portfolio C with the addition of Indirect Potable Reuse (IPR) with groundwater
injection and the construction of an AWPF (Advanced Water Purification Facility) (Palo Alto IPR option)
instead of Bay Water Desalination. The added local supply yield to supplement the existing imported
water supply from SFPUC would increase to 5,150 afy with the 2.5-mgd AWPF facility and groundwater
injection IPR facilities. Together with the usage offset yield expected by 2045 from the implementation of
Enhanced Conservation Phase 1 (724 afy), and Enhanced Conservation Phase 2 (618 afy), the portfolio
would gradually increase to yield a total of 6,492 afy to supplement SFPUC supplies. The OWP assumes a
10 percent dry year reduction to account for potential pumping restrictions during drought conditions.
Hence, the supplemental yield of the portfolio under drought conditions would be 5,978 afy. Figure 5.6
depicts the estimated sources of supply under the medium demand forecast. The difference between the
City’s demand and the Palo Alto IPR yield would be provided by RWS Supply.
This portfolio can only be implemented if Valley Water does not exercise the option to transfer a portion
of the treated effluent from the RWQCP because, with the transfer in effect there would not be sufficient
wastewater flows for the City to construct a viable IPR facility. This portfolio would offer the same added
supply reliability as Portfolio B (Enhanced Conservation only) until 2030, when the Palo Alto AWPF facility
is expected to become operational. Due to the anticipated need for more extensive community outreach
for DPR versus IPR, the implementation timeline anticipated to design, permit, and construct a dedicated
AWPF facility is faster than the DPR options.
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14,000
12,000
10,000
8,000
6,000
4,000
2,000
0
RWS Supply IPR with Palo Alto Facility
Enhanced Conservation, Phase 2Enhanced Conservation, Phase 1
Figure 5.6 Normal Year Supply and Demand Projection for Portfolio F
5.2.7 Portfolio G –Enhanced Conservation Phase 1 and 2 with Regional DPR
This portfolio is similar to Portfolio E with the addition of a Regional DPR water purification facility
constructed by Valley Water located in Palo Alto instead of a dedicated Palo Alto DPR Facility.
The added local supply yield to supplement RWS Supply would be 1,769 afy from the regional purification
facility. Together with the usage offset yield expected by 2045 from the implementation of Enhanced
Conservation Phase 1 (724 afy), and Enhanced Conservation Phase 2 (618 afy), the portfolio would
gradually increase to yield a total of 3,111 afy. The OWP assumes the DPR facility has a 5 percent dry year
reduction to account for lower wastewater flows due to increased water conservation during drought
conditions. Hence, the supplemental yield of the portfolio during drought conditions would be 3,023 afy.
Figure 5.7 depicts the estimated sources of supply and assumes the medium demand forecast.
Palo Alto can only implement this portfolio if Valley Water exercises the option to transfer a portion of the
treated effluent from the RWQCP because without the transfer there would be no Valley Water regional
facility located in Palo Alto.
Due to the long implementation timeline anticipated to implement the Regional DPR option, this portfolio
would provide the same added supply reliability as Portfolio B (Enhanced Conservation Phase 1 and 2)
until 2040 when the Regional Facility is assumed to become operational. A few of the challenges to
implement this option—that each could take years to complete—are the design, permitting, and
construction of a Regional Facility, as well as establishing an agreement for DPR water deliveries to Palo
Alto.
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14,000
12,000
10,000
8,000
6,000
4,000
2,000
0
SFPUC Supply DPR with Regional Facility
Enhanced Conservation, Phase 2Enhanced Conservation, Phase 1
Figure 5.7 Normal Year Supply and Demand Projection for Portfolio G
5.3 Evaluation Tool
The Palo Alto One Water Evaluation Tool facilitates the comparison of up to eight portfolios, each
comprising as many as 12 options, including combinations of up to 12 water conservation measures. The
Tool allows the user to develop and test the performance of the portfolios across a range of supply,
conservation, and demand scenarios. The OWP uses the Tool to evaluate the portfolios described above
but the Tool can also be used to evaluate new and different portfolios that may be developed and
considered in the future. Figure 5.8 shows a flow chart of the Evaluation Tool data inputs, user selections
and outputs, while Appendix D provides a more detailed description of the Tool and its functionalities.
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Figure 5.8 Evaluation Tool Flow Chart
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5.3.1 Data Inputs
Data inputs to the Tool include water demand forecast scenarios, option cost estimates (including capital
and O&M costs projected for each year in the projection period), option yields during normal and dry
years also projected for each year in the projection period, criteria and weightings to use to evaluate the
options as well as the criteria scores for qualitative criteria and sub-criteria. The qualitative sub-criteria in
the OWP are: Efficient use of Water, Ecological Benefit, Implementation Timeline, Operational Complexity,
and Public Acceptance.
5.3.2 User Selections
Within the tool, the user makes selections regarding future scenario assumptions including demand, Palo
Alto’s Shortage Stage of the Water Shortage Contingency Plan, the percentage cutback of RWS Supply for
Palo Alto, and whether Valley Water exercises the transfer option. The Tool assumes supply gaps are
mitigated based on the maximum planned conservation savings for the Shortage Stage selected from the
implementation of Palo Alto's Water Shortage Contingency Plan. “Unplanned Supply Gap” in the Tool
refers to additional supply gaps remaining beyond the planned conservation savings from the selected
Shortage Stage. The user also selects the start year for each option, the reduction percentage for each
water supply during dry years. The user then inputs portfolio names, selects options to include in each
portfolio, selects the cost year to display and the criteria weights.
The user selections used in the OWP to evaluate portfolios A through G include:
.
.
.
Demand Scenario: the medium demand scenario
Dry Year Reduction: a reduction in RWS Supply of 50 percent
Emergency Shortage Stage: assumed implementation of a Shortage Stage II (up to 20 percent) under
Palo Alto’s Water Shortage Contingency Plan
.Criteria Weights: Chapter 4, Section 4.3 presents the criteria weights selected for this OWP
The OWP assumes a reduction in RWS Supply of 50 percent as the City anticipates the need to implement
water use reductions in the range of 35 percent to 55 percent during droughts after the implementation
of the Bay-Delta Plan. This assumption is close to the high-end of that range to plan for the largest
expected cutbacks.
Palo Alto has a Water Shortage Contingency Plan with six stages, including Shortage Stage V which
provides for up to a 50 percent cutback. This would fully mitigate the reduction in RWS Supply through
water use restrictions and customer response. However, this Shortage Stage would be very impactful to
Palo Alto residents and businesses, and it would involve drought rate structures, water allocations, and
severe water use restrictions. Additionally, making this assumption for analytical purposes would not yield
different results across portfolios to test the water supply benefits of the different portfolios during
droughts. For this reason, the OWP assumes Palo Alto implements a Shortage Stage II (up to 20 percent
water savings).
Given these stated assumptions, the resulting unplanned supply gap quantities are for illustrative
purposes only and do not represent a dire projection for Palo Alto’s water supply. The unplanned supply
gap quantities provide a comparison metric to examine which portfolio limits the unplanned supply gap
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to a greater or lesser degree, thus limiting the severity of severely impactful drought measures Palo Alto
must implement.
It should be noted that although the RWS Supply cutback assumption of 50 percent is maintained across
all Portfolios, the resulting cutback volume varies by portfolio as it is assumed that it will be based on the
normal year RWS Supply volume with the respective portfolio supply and conservation options
implemented. For example, for Portfolio D (Enhanced Conservation Phase 1 and 2 with Groundwater), the
City has a total demand of 12,546 afy in 2045. In a normal year, this portfolio includes 724 afy from
Enhanced Conservation Phase 1, 618 afy from Enhanced Conservation Phase 2, and 2,250 afy from
groundwater. This results in normal year RWS Supply need of 8,953 afy. During a 50 percent RWS Supply
cutback, this normal year demand would be reduced by 50 percent to 4,477 afy.
For ease of comparison, the portfolio evaluation keeps assumptions constant. However, the user can
modify each of these key assumptions in the Evaluation Tool based upon changing conditions. In
addition, Section 5.6 analyzes the sensitivity of the results to changing many of these key assumptions.
5.3.3 Tool Outputs
The Tool summarizes data inputs and user selections at the portfolio level. The sections below provide an
overview of each of the main outputs from the tool (Portfolio Evaluation, Portfolio Supply Summary, and
Portfolio Cost Estimates). Appendix D provides screenshots illustrating the Tool interface and graphical
outputs from the Tool. The subsequent Evaluation Results section 5.4 of this chapter provides the results
of the Tool outputs for the portfolio evaluation as well as the portfolio supply summary, and portfolio cost
estimates.
5.3.3.1 Portfolio Evaluation
The portfolio evaluation is the development of weighted evaluation criteria scores for each portfolio and
the comparison of weighted evaluation criteria scores across portfolios. To calculate the weighted
evaluation criteria scores for each portfolio, the Tool first calculates the raw criteria score for each
portfolio by combining the qualitative criteria scores for each option (user input), with the calculated
quantitative criteria scores for each option (for the OWP, the quantitative criteria are Cost and Reliability
and the quantitative sub-criterion is Reliance on Tuolumne). With the combined raw criteria scores,
together with the assumptions and scenarios selected by the Tool user, the Tool calculates the weighted
portfolio scores for each evaluation criteria by multiplying the raw criteria score for each portfolio by the
user-selected criteria weighting and normalizing the score on a scale of 1 - 5. Table 5.4 and Table 5.5
present the raw and weighted criteria scores by portfolio, respectively.
The weighted score for each portfolio allows the portfolios to be evaluated by comparing them to the
Baseline Portfolio and comparing across portfolios. The portfolio with the highest score is the most
beneficial for Palo Alto based upon the assumptions and criteria weightings specified. Additionally, the
portfolio evaluation presents the weighted portfolio scores for each portfolio and for both Valley Water to
exercise or not exercise the option to transfer a portion of the treated effluent from the RWQCP.
For more details on the criteria weighting, see Section 4.3.
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5.3.3.2 Portfolio Supply Summary
The Tool includes a normal and dry year supply analysis simulated for each portfolio. The normal year
analysis is based on the full yield of each option, (including the usage offset yield from the Enhanced
Conservation options) and the demand for RWS Supply; the Tool calculates demand for RWS Supply as
the difference between the selected demand scenario (low, medium, high) and the combined yield for the
supplies included in the respective portfolio. In the dry year analysis, the Tool calculates the available
supply from the RWS as the normal year supply multiplied by the dry year reduction percentage selected
by the user. A user-selected dry year reduction percentage is also applied to the other options, where
applicable as listed in Table 5.1.
5.3.3.3 Portfolio Cost Estimates
The Tool uses the cost estimates provided by the user to calculate portfolio weighted unit costs based on
normal year supply conditions. The Tool can express the portfolio weighted unit costs in 2023 dollars and
2045 dollars. The weighted unit costs are projected for each year based on inflation assumptions outlined
in the costs section of Chapter 3 for each option as well as in Appendix C.
5.4 Portfolio Evaluation Results
The Supply Evaluation Tool was used to evaluate the seven portfolios (A through G). The results presented
herein are based on the medium demand scenario, and an RWS Supply reduction of 50 percent,
combined with the implementation of a Level II (up to 20 percent) Emergency Shortage. For ease of
comparison, these assumptions are kept constant in the portfolio evaluations described in the following
subsections. However, each of these key assumptions can be modified in the Evaluation Tool based
changing conditions. In addition, the sensitivity of many of these key assumptions are analyzed and
discussed separately in Section 5.6.
Table 5.4 and Table 5.5 summarize the raw and weighted portfolio evaluation scores, respectively. The top
three scores for each criterion and for the total score are shown in bold font. It can be concluded that
Portfolio B (Enhanced Conservation Phase 1 and 2) has the highest raw score, while Portfolio E (Enhanced
Conservation Phase 1 and 2 with Palo Alto DPR) has the highest weighted score.
Additionally, the weighted portfolio evaluation scores are also presented graphically in Figure 5.9 and
Figure 5.10. As shown, the unit cost and reliability scores are shown in red and blue, respectively, while the
three environmental benefit sub criteria are shown in different shades of green. Similarly, the three ease of
implementation subcategories are shown in different shades of purple. Figure 5.9 shows the results if
Valley Water does not exercise the option to transfer a portion of effluent from the RWQCP, while
Figure 5.10 shows the results if Valley Water does exercise the transfer option. It can be concluded that
Portfolio E (Enhanced Conservation Phase 1 and 2 with Palo Alto DPR) has the highest score if Valley
Water does not exercise the effluent transfer option, while Portfolio G (Enhanced Conservation Phase 1
and 2 with Regional DPR) has the highest score if Valley Water does exercise the effluent transfer option.
Hence, the combination of enhanced conservation and a type of DPR is the most attractive path forward
to further strengthen Palo Alto’s supply reliability, independent of Valley Water’s decision of exercising the
transfer option.
A discussion of the portfolio evaluation results by portfolio in alphabetical order is presented in the
following subsections, while a more detailed comparison between the portfolios is discussed in
Section 5.5.1.
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Table 5.4 Portfolio Evaluation Results – Raw Scores
C. Enhanced
Conservation
Conservation with Bay Water
D. Enhanced
Conservation
with
E. Enhanced
Conservation
with Palo Alto
DPR(2)
F. Enhanced
Conservation
with Palo Alto
IPR(2)
G. Enhanced
Conservation
with Regional
DPR(3)
B. Enhanced
Criteria Sub-Criteria
Unit Cost
A. Baseline(2) Phase 1 and 2(2) Desalination(2) Groundwater(2)
Unit Cost(1)
Reliability
4.73
1.00
2.00
2.00
1.00
5.00
5.00
1.71
2.32
2.21
1.43
5.96
1.00
4.09
2.68
1.86
2.86
7.40
2.93
2.43
2.32
2.39
2.15
6.86
3.50
3.97
3.07
2.21
2.93
8.21
1.32
3.90
2.73
2.21
3.07
8.01
4.06
2.56
2.60
2.21
1.99
6.80
Reliability
Efficient Use of Water
Ecological Benefit
Reliance on Tuolumne
Subtotal
Environmental
Benefits
Implementation
Timeline 5.00 4.74 3.31 4.38 3.23 3.51 4.17
Ease of
Implementation Operational Complexity
Public Acceptance
Subtotal
5.00
5.00
4.84
4.84
3.42
4.13
4.48
4.48
3.34
3.71
3.61
4.02
4.84
4.42
15.00
25.73
14.42
27.09
10.86
23.34
13.34
25.56
10.28
25.96
11.14
24.37
13.43
26.85Total(2,3)
Notes:
The top three scores for each criterion and for the total score are shown in bold.
(1) Based on estimated year 2045.
(2) Portfolios A-F assume that Valley Water does not exercise its option (selected “No” in the Tool).
(3) Portfolio G assumes that Valley Water does not exercise its option to transfer a portion of RWQCP treated effluent (selected “Yes” in the Tool).
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Table 5.5 Portfolio Evaluation Results – Weighted Scores
C. Enhanced
B. Enhanced Conservation D. Enhanced E. Enhanced F. Enhanced G. Enhanced
Conservation
Phase 1 and
2(2)
with Bay
Water
Desalination(2) Groundwater(2)
Conservation Conservation Conservation Conservation
with with Palo Alto with Palo Alto with RegionalCriteriaA.
Criteria Sub-Criteria
Unit Cost
Weight
20%
35%
10%
10%
10%
30%
Baseline(2)DPR(2)
0.70
1.39
0.31
0.22
0.29
0.82
IPR(2)
0.26
1.37
0.27
0.22
0.31
0.80
DPR(3)
0.81
0.90
0.26
0.22
0.20
0.68
Unit Cost(1)
Reliability
0.95 1.00
0.60
0.23
0.22
0.14
0.59
0.20
1.43
0.27
0.19
0.29
0.75
0.59
0.85
0.23
0.24
0.21
0.68
Reliability 0.35
Efficient Use of Water
Ecological Benefit
Reliance on Tuolumne
Subtotal
0.20
0.20Environmental
Benefits 0.10
0.50
Implementation
Timeline 5%
5%
0.25
0.25
0.24
0.24
0.17
0.17
0.22
0.22
0.16
0.17
0.18
0.18
0.21
0.24Operational
ComplexityEase of
Implementation
Public Acceptance 5%
15%
100%
0.25
0.75
2.55
0.24
0.72
2.92
0.21
0.55
2.91
0.22
0.66
2.79
0.19
0.52
3.43
0.20
0.56
2.99
0.22
0.67
3.06
Subtotal
Total(2, 3)
Notes:
The top three scores for each criterion and for the total score are shown in bold.
(1) Based on estimated year 2045.
(2) Portfolios A-F assume that Valley Water does not exercise its option (selected “No” in the Tool).
(3) Portfolio G assumes that Valley Water does not exercise its option to transfer a portion of RWQCP treated effluent (selected “Yes” in the Tool).
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Figure 5.9 Weighted Portfolio Scores without the Valley Water Transfer option
Figure 5.10 Weighted Portfolio Scores with the Valley Water Transfer option
5.4.1 Portfolio A - Baseline
Portfolio A has a weighted unit cost of $2,210/af in 2023 dollars and $4,088/af in 2045 dollars as listed in
Table 5.7. This portfolio has a total weighted criteria score (2.55) as listed in Table 5.5. This portfolio scores
high (0.95) in the unit cost criteria due to the relatively low unit cost. It also scores high for ease of
implementation (0.75) as this is the City’s existing potable water supply. This portfolio scores the lowest of
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all the portfolios (0.35) in the reliability criteria and in the environmental benefits criteria (0.5) due to its
reliance on the Tuolumne River.
5.4.2 Portfolio B – Enhanced Conservation Phase 1 and 2
Portfolio B has a weighted unit cost of $2,075/af in 2023 dollars and $3,903/af in 2045 dollars as listed in
Table 5.7. This portfolio has a total weighted criteria score (2.91) as listed in Table 5.5. The relatively low
cost of conservation measures contributes to this portfolio’s top score for unit cost (1.00). Additionally,
conservation measures also have a relatively high ease of implementation compared with some of the
more infrastructure intensive portfolios, which leads to a high ease of implementation score for this
portfolio (0.72). Although water conservation has substantial environmental benefits, the yields are limited
and this contributes to the relatively low weighted criteria score for environmental benefits (0.59) and
reliability (0.60).
5.4.3 Portfolio C – Enhanced Conservation Phase 1 and 2 with Bay Water
Desalination
Portfolio C has a weighted unit cost of $3,854/af in 2023 dollars and $6,663/af in 2045 dollars as listed in
Table 5.7. This portfolio has a total weighted criteria score (2.91) as listed in Table 5.5. With the addition of
the costly desalination plant of approximately $252 million (2023 dollars) and land acquisition estimated
at $43 million (2023 dollars) and the associated high O&M cost including energy costs together totaling
approximately $11 million per year (2023 dollars), this portfolio receives a low score for unit cost (0.20).
This desalination plant would have a capacity of 5-mgd (4,480 AFY) which contributes to this portfolio’s
high reliability score (1.43). This portfolio receives a low score in the implementation category (combined
score of 0.55). Due to the long implementation timeline of the desalination plant, it should be noted that
most of the added reliability benefit would not be realized until 2035 or beyond. While environmental
impacts associated with a bay water desalination plant would be substantial, this portfolio would
substantially reduce the City’s reliance on the Tuolumne River and this contributes to the portfolio’s
relatively high environmental benefits score (0.75).
5.4.4 Portfolio D – Enhanced Conservation Phase 1 and 2 with Groundwater
Portfolio D has a weighted unit cost of $2,566/af in 2023 dollars and $5,330/af in 2045 dollars as listed in
Table 5.7. This portfolio has a total weighted criteria score (2.78) as listed in Table 5.5. The conversion of
the City’s emergency groundwater wells to regular operations with full treatment would add a combined
yield of 2,250 AFY in addition to RWS with enhanced water conservation Phase 1 and Phase 2. Because
this is a moderate yield compared to some of the larger water reuse options, and because groundwater is
subject to Valley Water’s voluntary and mandatory calls for water use restrictions during drought, this
portfolio receives a medium score for reliability (0.85). Treatment facilities for groundwater are costly
($23 million in 2023 dollars) and conveyance is necessary for brine disposal from the treatment process
($26 million in 2023 dollars). The unit cost of groundwater with treatment is relatively high also due to the
O&M cost for treatment ($1.8 million per year), as well as the groundwater production charge imposed by
Valley Water ($5.2 million per year) shown in Appendix C. This portfolio receives a relatively low score for
unit cost of (0.59). This portfolio can be implemented whether or not Valley Water exercises its option to
transfer a portion of treated effluent from the RWQCP. This portfolio receives a medium score in
environmental benefits (0.68) and ease of implementation (0.66) compared to all seven portfolios. In other
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words, it does not perform very well nor very poor in any of the categories. Due to the ease of
implementation compared to the other portfolios with new large local supply sources (Desal, IPR, and
DPR), it should be noted that most of the added reliability benefit of this portfolio could be realized as
soon as 2025.
5.4.5 Portfolio E – Enhanced Conservation Phase 1 and 2 with Palo Alto DPR
Portfolio E has a weighted unit cost of $2,654/af in 2023 dollars and $4,938/af in 2045 dollars as listed in
Table 5.7. This portfolio has a total weighted criteria score of (3.43) as listed in Table 5.5. The addition of a
Palo Alto DPR facility with a yield of 4,723 AFY would have a combined cost of approximately $105 million
in 2023 dollars. Land acquisition is estimated to cost an additional $11 million and annual O&M costs
including energy required for treatment would be approximately $9.4 million (2023 dollars). These costs
contribute to the low to moderate unit cost (0.70). However, the reliability score is high for this option
(1.39) due to the high yield that is not likely sensitive to drought cutbacks. Although, the reliability benefit
of this portfolio would not be realized until 2035 or beyond due to the long implementation timeline of
the Palo Alto DPR facility. This portfolio scores low on ease of implementation (0.52) and high on
environmental benefits (0.82).
5.4.6 Portfolio F – Enhanced Conservation Phase 1 and 2 with IPR
Portfolio F has a weighted unit cost of $3,323/af in 2023 dollars and $6,440/af in 2045 dollars as listed in
Table 5.7. This portfolio has a total weighted criteria score (2.99) as listed in Table 5.5. The addition of a
Palo Alto IPR water purification facility, with injection wells and subsequent treatment of groundwater
extracted at three existing City wells would add approximately $189 million in capital costs. Land
acquisition is estimated at $7.4 million. Treatment O&M is estimated at $6 million annually with nearly
$1 million in additional energy costs. Additionally, since IPR relies on pumping groundwater, it is sensitive
to the projected escalation of the groundwater production charges that are estimated to cost $5.7 million
annually (2023 dollars). This portfolio receives one of the lowest scores for unit cost (0.26) and also a low
score for ease of implementation. However, the yield of IPR is the highest of all the alternative water
supply projects at 5,150 AFY, which contributes to this portfolio’s high reliability score (1.37). This portfolio
scores fairly high on environmental benefits primarily because its high yield reduces the City’s reliance on
the RWS. Portfolio F can only be implemented if Valley Water elects to not exercise its option to transfer a
portion of treated effluent from the RWQCP.
5.4.7 Portfolio G – Enhanced Conservation Phase 1 and 2 with Regional DPR
Portfolio G has a weighted unit cost of $2,355/af in 2023 dollars and $4,552/af in 2045 dollars as listed in
Table 5.7. This portfolio has a total weighted criteria score (3.06) as listed in Table 5.5. The OWP estimates
that the cost of 1,763 AFY of water from a Regional DPR facility would be approximately $6 million per
year (2023 dollars). Palo Alto would need to also build conveyance from the Regional DPR facility to the
Palo Alto water distribution system and this would be approximately $16.4 million additional in capital
costs. Despite these costs, the portfolio is one of the highest scoring for the unit cost criteria (0.81) and
also scores high in the ease of implementation criteria (0.67) because Palo Alto is not the project owner
and rather would work in close partnership with Valley Water on the facility. Nevertheless, the facility
would have a long implementation timeline and reliability benefits would not be realized until 2040 or
beyond. The portfolio receives a moderate score for reliability (0.90). This portfolio also receives a
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moderate score for environmental benefits (0.68). Notably, this portfolio is only possible if Valley Water
opts to exercise its option to transfer a portion of the RWQCP’s treated effluent and builds a Regional
DPR facility located in Palo Alto.
5.5 Portfolio Evaluation Comparisons
This section describes a comparison of the portfolio evaluation results following the three key outputs
from the Tool, namely the portfolio evaluation scores, the supply mix and potential for unplanned
shortfalls under various RWS cutback and Shortage State declarations, and lastly the portfolio costs. This
section is concluded with a summary of the results with respect to the decision of Valley Water to exercise
the option to transfer a portion of the RWQCP effluent.
5.5.1 Portfolio Scores
Based upon the raw criteria scores shown in Table 5.4, the highest scoring portfolios are:
.
.
.
Portfolio B (Enhanced Conservation Phase 1 and 2
Portfolio E (Enhanced Conservation with Palo Alto DPR) and
Portfolio G (Enhanced Conservation with Regional DPR)
Portfolios B and G score highly in the Unit Cost and Ease of Implementation Criteria, while Portfolio E has
a relatively high score for Reliability and Environmental Benefits. Based upon the weighted criteria scores
shown in Table 5.5, the highest scoring portfolios are:
.
.
.
Portfolio E (Enhanced Conservation with Palo Alto DPR),
Portfolio G (Enhanced Conservation with Regional DPR) and
Portfolio F (Enhanced Conservation with Palo Alto IPR)
Portfolio E and G are top-scoring portfolios based on raw and weighted criteria, while Portfolio B is only a
top-scoring portfolio with raw criteria scores. This is because Portfolio B has one of the lowest weighted
criteria scores for Reliability. Portfolio B does not introduce an alternative water supply source while each
of the Portfolios C through G each introduce an alternative water supply source.
Based upon the weighted criteria scores, Portfolio F (Enhanced Conservation with Palo Alto IPR) rises to be
one of the top three highest-scoring portfolios. This Portfolio scores higher on Reliability and
Environmental Benefits relative to the other portfolios. Notably, Portfolio E and F are only feasible if Valley
Water does not exercise its option to transfer a portion of the RWQCP effluent, while Portfolio G is only
feasible if Valley Water Transfer does exercise the option.
The reasons explaining the weighted scoring results are presented below in alphabetical order.
Portfolio B – Enhanced Conservation Phase 1 and 2
Although Portfolio B (Enhanced Conservation Phase 1 and 2) is not a top-scoring portfolio looking at
portfolio weighted criteria scores, the portfolio scores more highly in the Reliability criteria (0.60)
compared to the Baseline Portfolio (0.35) and also scores higher for Environmental Benefits weighted
criteria (0.59) compared to the Baseline Portfolio (0.50). This portfolio scores similarly in the Ease of
Implementation criteria compared to the Baseline Portfolio (with a weighted score of 0.72 compared to
0.75 for the Baseline Portfolio). Additionally, Enhanced Conservation Phase 1 and Phase 2 measures are
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beneficial irrespective of which water supply infrastructure option Palo Alto moves forward with. For these
reasons, all other portfolios (C through G) include Enhanced Conservation Phase 1 and Phase 2.
Portfolio C – Enhanced Conservation Phase 1 and 2 with Bay Water Desalination
Portfolio C (Enhanced Conservation with Bay Water Desalination) scores highly in the Reliability criteria,
and in the Environmental Benefits criteria, despite having the lowest score in the Ecological Benefit
sub-criteria. This portfolio scores more highly in the environmental benefits criteria due to the quantity of
water available to supplement the RWS Supply and reduce Palo Alto’s Reliance on the Tuolumne River
during dry and normal years. This portfolio receives the lowest weighted unit cost criteria score of all the
portfolios and also receives one of the lowest weighted criteria scores for the ease of implementation
criteria. The weighted unit cost score is the primary reason that this option performs worse in the portfolio
than as a standalone option, as described at the end of Chapter 4.
Portfolio D – Enhanced Conservation Phase 1 and 2 with Groundwater
Portfolio D (Enhanced Conservation with Groundwater) scores in the middle for all weighted criteria
scores compared to all seven portfolios. The weighted score for the Environmental Benefits criteria is 0.68
which is higher than the Baseline Portfolio weighted score of 0.5. The weighted score for the Ease of
Implementation criteria is 0.66, which is lower than the Baseline Portfolio A and Portfolio B (Enhanced
Conservation Phase 1 and 2) and is higher than portfolios C, E and F, which each include a large Palo Alto
infrastructure project. Because this portfolio does not score highly in any particular criteria category, it is
not one of the most highly scoring portfolios. Palo Alto could realize most of the added reliability benefit
of this portfolio more quickly than for the water purification or desalination options. However, this option
would require a RO Concentrate pipeline to be constructed from the location of the wells to the RWQCP
outfall pipeline, which is a costly and time-consuming capital project. Additionally, this Portfolio utilizes
city-owned park sites for installing treatment facilities and does not require additional cost and time for
land acquisition.
Portfolio E – Enhanced Conservation Phase 1 and 2 with Palo Alto DPR
Portfolio E (Enhanced Conservation with Palo Alto DPR) has a weighted criteria score (3.43), which is the
highest scoring portfolio. This portfolio has a high weighted criteria score for reliability (1.39) and is the
highest scoring portfolio for the Environmental Benefits weighted criteria (0.82). This portfolio scores the
lowest of all portfolios for the Ease of Implementation weighted criteria (0.52).
Portfolio F – Enhanced Conservation Phase 1 and 2 with IPR
Portfolio F (Enhanced Conservation with Palo Alto IPR) has the third highest weighted criteria score (2.99).
Portfolio F has the second highest unit cost of all seven portfolios (only Portfolio C Enhanced
Conservation Phase 1 and 2 with Bay Water Desalination is more expensive), and therefore Portfolio F has
a low weighted cost score of 0.26. However, this portfolio has a high weighted score for reliability (1.37)
compared to the Baseline Portfolio benchmark of 0.35. This portfolio has a high weighted criteria score
(0.80) for the Environmental Benefits criteria; this is almost as high as the highest scoring portfolio
Portfolio E (Palo Alto DPR). This portfolio has a low weighted score of 0.56 for the Ease of Implementation
criteria. It should be noted that a significant increase in supply reliability could likely be realized faster with
Portfolio F (Enhanced Conservation Phase 1 and 2 with Palo Alto IPR) compared to Portfolio C (Enhanced
Conservation Phase 1 and 2 with Bay Water Desalination) or Portfolio E or G which both include DPR
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facilities. This is because there is an anticipated need for more extensive community outreach and
additional pilot testing to optimize and verify treatment schemes for DPR versus IPR.
Portfolio G – Enhanced Conservation Phase 1 and 2 with Regional DPR
Portfolio G (Enhanced Conservation with Regional DPR) is the portfolio with the second highest weighted
criteria score (3.06). With the Regional DPR facility, the unit cost of Portfolio G is significantly higher than
the Baseline Portfolio A and Portfolio B (Enhanced Conservation Phase 1 and Phase 2). Portfolio G has a
medium unit cost compared to all seven portfolios, and therefore has a medium cost score (0.81), while
this portfolio also has an above average reliability score (0.90) compared to the Baseline Portfolio
benchmark of 0.35. This portfolio has a medium weighted score for the Environmental Benefits criteria
(0.68) compared to other portfolios. This portfolio has a weighted score of 0.67 for Ease of
Implementation, which is a higher weighted score than other portfolios that involve infrastructure projects
that Palo Alto would build itself and is a lower score than the Baseline Portfolio A or Portfolio B (Enhanced
Conservation Phase 1 and 2).
5.5.2 Portfolio Supply Mix and Unplanned Shortfalls
Figure 5.11 provides a graphical summary from the Tool output that compares Palo Alto’s year 2045 water
supply yields and demands of the seven portfolios side-by-side for a normal year conditions.
Figure 5.11 Normal Year Supply and Demand Analysis by Portfolio for 2045
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As shown in Figure 5.11, the amount of RWS Supply varies considerably between the portfolios, ranging
from 100 percent of the forecasted demand in 2045 of 12,546 afy (medium growth scenario) in Portfolio A
to as low as 6,053 afy or 48 percent of the total demand in Portfolio F. There is no unplanned supply
shortfall for any of the portfolios under normal year supply and demand conditions.
However, as shown in Figure 5.12, the supply and demand balance would change drastically under dry
year conditions with an assumed 50 percent cutback of RWS Supply. Under these conditions, it is likely
that the City would (as a minimum) declare a Shortage Stage II, which would trigger a 20 percent
mandatory demand reduction per the City’s Water Shortage Contingency Plan.
Figure 5.12 Dry Year Supply and Demand Analysis by Portfolio for 2045 with a 50 percent RWS Supply Cutback
Based on 2045 demand conditions, a 20 percent demand reduction would lower the normal year demand
of 12,546 afy to a reduced “wet” demand of 10,037 afy. If the City’s supply from the RWS were subject to a
50 percent cutback, the City would still receive 50 percent of 12,546 AFY, which amounts to 6,273 AFY.
Hence, the unplanned supply gap would be 3,764 afy (10,037-6,273) for the Baseline Portfolio A. This
unplanned supply gap is depicted in Figure 5.12 with the red hatched area of the bar chart. An unplanned
supply gap of 3,764 afy, equates to 30 percent of the projected normal year demand of 12,546 afy in year
2045.
For analytical purposes, this analysis assumes that the City would only implement a Shortage Stage II to
assess how robust each portfolio is to withstand the effects of drought. However, realistically, Palo Alto
would consider implementing Shortage Stage V to target a 50 percent demand reduction if faced with a
50 percent supply reduction.
Unplanned supply gaps (shown as red hatched areas in Figure 5.12 and listed in Table 5.6, range from
18 percent to 77 percent in Portfolios B through G. As listed in Table 5.6, Portfolio B accomplishes an
18 percent reduction in the unplanned supply gap relative to the baseline through the implementation of
the enhanced water conservation Phase 1 and Phase 2 measures. Portfolios C, E, and F each reduce the
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unplanned supply gap by greater than 70 percent relative to the baseline portfolio. While Portfolios D and
G achieve a 36 percent and 39 percent reduction in the unplanned supply gap, respectively, relative to the
baseline portfolio.
Table 5.6 Unplanned Supply Gap Volumes by Portfolio During Dry Year
% Reduction in
Baseline Unplanned
Supply Gap Volume
Unplanned Supply
Gap Volume (AF)Portfolio
A. Baseline 3,764
3,092
852
0%
18%
77%
36%
74%
73%
39%
B. Enhanced Conservation Phase 1 and 2
C. Enhanced Conservation Phase 1 and 2 with Bay Water Desalination
D. Enhanced Conservation Phase 1 and 2 with Groundwater
E. Enhanced Conservation Phase 1 and 2 with Palo Alto DPR
F. Enhanced Conservation Phase 1 and 2 with Palo Alto IPR
G. Enhanced Conservation Phase 1 and 2 with Regional DPR
2,417
967
1,032
2,296
5.5.3 Portfolio Costs
The Evaluation Tool also calculates and compares the weighted unit costs for each portfolio. As noted in
the tool description and Appendix D, the Tool can compare unit costs for each planning year from 2023
dollars through 2045 dollars. Note that some water supply options have extended implementation
timelines of a decade or more and the expression of the cost in 2023 dollars is for comparison purposes
only. Figure 5.13 and Figure 5.14 resent the unit cost comparisons by portfolio expressed in 2023 dollars
and 2045 dollars, respectively. These figures depict the relative contribution of the total unit cost by
supply and water conservation option component. In addition, the total unit costs for each portfolio in
both 2023 and 2045 dollars are summarized in Table 5.7.
Table 5.7 Total Estimated Unit Cost by Portfolio
Portfolio Unit Cost in 2023
dollars ($/af)
Unit Cost in 2045
dollars ($/af)
A. Baseline $2,210
$2,075
$3,854
$2,556
$2,645
$3,323
$2,355
$4,088
$3,903
$6,663
$5,330
$4,938
$6,440
$4,552
B. Enhanced Conservation Phase 1 and 2
C. Enhanced Conservation Phase 1 and 2 with Bay Water Desalination
D. Enhanced Conservation Phase 1 and 2 with Groundwater
E. Enhanced Conservation Phase 1 and 2 with Palo Alto DPR
F. Enhanced Conservation Phase 1 and 2 with Palo Alto IPR
G. Enhanced Conservation Phase 1 and 2 with Regional DPR
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Figure 5.13 Weighted Unit Cost by Portfolio (2023 dollars)
Figure 5.14 Weighted Unit Cost by Portfolio (2045 dollars)
The following subsections provide observation about the weighted unit costs each portfolio in
alphabetical order.
Portfolio A – Baseline
With Baseline Portfolio A, the unit cost of RWS Supply is as forecasted in SFPUC’s 10-year Financial Plan
for FY 2023/24 to FY 2032/33 (SFPUC, 2023b) through year 2033 and a subsequent extrapolation of unit
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cost based on the average historical rate increase since 2013 applied to years 2034 to 2045. The portfolio
weighted unit cost is anticipated to increase from $2,210/af in 2023 to $4,088/af in 2045.
Portfolio B – Enhanced Conservation Phase 1 and 2
Portfolio B (Enhanced Conservation Phase 1 and 2) has the lowest unit cost and is the only portfolio with a
lower weighted unit cost than the baseline Portfolio A. The portfolio weighted unit cost of Portfolio B is
$2,075/af in 2023 dollars. This unit cost is mostly driven by the projected unit cost of SFPUC’s water
deliveries ($2,210/af), and to a lesser extent by the cost of Enhanced Conservation Phase 1 ($323/af) and
Phase 2 ($1,939/af).
Portfolio C – Enhanced Conservation Phase 1 and 2 with Bay Water Desalination
Portfolio C (Enhanced Conservation Phase 1 and 2 with Bay Water Desalination) is the most expensive
when expressed in both 2023 and 2045 dollars. With the addition of the costly desalination plant, with an
estimated capital cost of roughly $252 million in 2023 dollars (excluding land acquisition cost), and the
associate high O&M cost, the unit cost of this portfolio are significantly higher than the Baseline Portfolio
A and Portfolio B (Enhanced Conservation Phase 1 and 2). Table 3.2 shows the capital and O&M costs for
Bay Water Desalination and other options. The portfolio weighted unit costs of Portfolio C are estimated
to increase from $3,854/af in 2023 to $6,663/af in 2045.
Portfolio D – Enhanced Conservation Phase 1 and 2 with Groundwater
Portfolio D (Enhanced Conservation with Groundwater) is more expensive than the baseline in both 2023
and 2045 dollars and is more expensive than Portfolio E (Enhanced Conservation Phase 1 and 2 with Palo
Alto DPR) and Portfolio G (Enhanced Conservation Phase 1 and 2 with Regional DPR) in 2045 dollars.
Portfolio D has a weighted average portfolio unit cost of $2,556/af in 2023 dollars and $5,330/af in 2045
dollars. Despite the much lower capital cost required for the groundwater treatment facilities ($50 million
in 2023 dollars) compared to the Bay Water Desalination and Palo Alto DPR options, the unit cost of
groundwater is relatively high due to the O&M cost for treatment of Fe, Mn, and TDS, as well as the
groundwater production charge imposed by Valley Water. With the addition of treated groundwater, the
unit cost of this portfolio is significantly higher than Baseline Portfolio A and Portfolio B (Enhanced
Conservation Phase 1 and Phase 2).
Portfolio E – Enhanced Conservation Phase 1 and 2 with Palo Alto DPR
Portfolio E (Enhanced Conservation Phase 1 and 2 with Palo Alto DPR) and Portfolio G (Enhanced
Conservation Phase 1 and 2 with Regional DPR) have a similar weighted unit cost in 2023 and 2045
dollars. For Portfolio E (Enhanced Conservation with Palo Alto DPR), with the addition of the costly
advanced water treatment facility, estimated at roughly $105 million in 2023 dollars (excluding land
acquisition cost) and the associated high O&M cost, the unit costs of this portfolio are significantly higher
than Baseline Portfolio A and Portfolio B (Enhanced Conservation Phase 1 and 2). Portfolio E has a
weighted average portfolio unit cost of $2,645/af in 2023 dollars and $4,938/af in 2045 dollars.
Portfolio F – Enhanced Conservation Phase 1 and 2 with IPR
Portfolio F (Enhanced Conservation Phase 1 and 2 with Palo Alto IPR) is the second most expensive
portfolio and it is relatively more expensive when expressed in 2045 dollars and gets nearly as expensive
and Portfolio C (Enhanced Conservation Phase 1 and 2 with Bay Water Desalination). Portfolio F
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(Enhanced Conservation Phase 1 and 2 with Palo Alto IPR) and Portfolio D (Enhanced Conservation with
Groundwater) each become relatively more expensive when expressed in 2045 dollars due to the faster
escalation of the groundwater water production charge compared to the inflation correction for the
option components of the other portfolios.
Portfolio F, with the addition of the costly Palo Alto IPR project (estimated at roughly $189 million in
capital cost in 2023 dollars, excluding land acquisition cost) and the associated high O&M cost and
groundwater production charges, the weighted unit cost of this portfolio are significantly higher than the
Baseline Portfolio A and Portfolio B (Enhanced Conservation Phase 1 and 2). Portfolio F has a weighted
average portfolio unit cost estimated to increase from $3,323/af in 2023 to $6,440/af in 2045.
Portfolio G – Enhanced Conservation Phase 1 and 2 with Regional DPR
Portfolio G has a weighted average portfolio unit cost of $2,355/af in 2023 dollars and $4,552/af in 2045
dollars. The Regional Facility in this portfolio is owned and operated by Valley Water and the Portfolio
assumes Palo Alto’s cost is via an O&M payment to Valley Water to pay for the cost of treating the water
that is estimated at $6 million in 2023 dollars annually while capital costs of approximately $16.4 million
are primarily to pay for conveyance of the water to Palo Alto’s distribution system.
5.5.4 Valley Water Transfer Decision
Figure 5.15 shows the highest scoring portfolios with green scores, the medium scoring portfolios with
yellow scores, and the lowest scoring portfolios with red scores. This figure also organizes the scores
based on the dependency of each portfolio on the Valley Water Transfer option decision. Key
observations from the portfolio evaluation, considering the scores and cost estimates, are provided below
the figure.
Figure 5.15 Portfolio Evaluation Results Schematic with Valley Water Transfer trigger
Portfolio B (Enhanced Conservation Phase 1 and Phase 2) is the cheapest portfolio and for this reason is
the portfolio with the highest score for weighted criteria unit cost. Additionally, Portfolio B scores among
the highest weighted criteria score for Ease of Implementation (the only portfolio with a higher score is
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the baseline). Investing in the enhanced conservation program to supplement the already planned water
conservation measures and targets is beneficial, irrespective of which water supply infrastructure option
Palo Alto moves forward with. However, water conservation alone is not sufficient to significantly reduce
or eliminate an unplanned supply gap. Portfolio B has an overall weighted criteria score of 2.91, which is
not a top scoring portfolio, however it is a higher score than the baseline.
If Valley Water does not exercise its option to transfer a portion of RWQCP treated effluent, the most
cost-effective and beneficial option to add to the enhanced water conservation options is the Palo Alto
DPR Facility, as in Portfolio E. This portfolio has a weighted unit cost of $2,645/af in 2023 dollars and
$4,938/af in 2045 dollars and would reduce the unplanned supply gap from 3,764 afy (Baseline) by
74 percent to 967 afy, this is close to the largest reduction in unplanned supply gap of any of the
portfolios (which is a 77 percent reduction to 852 afy from Portfolio C (Enhanced Conservation with Bay
Water Desalination). The overall weighted criteria score of this portfolio is 3.43 as shown in green in
Figure 5.9, the highest score of any portfolio.
If Valley Water exercises its option to transfer a portion of RWQCP treated effluent, the most
cost-effective and beneficial option to add to the enhanced water conservation options is the Regional
DPR Facility, as combined in Portfolio G. However, the unplanned supply gap volume would only be
reduced from 3,764 afy (Baseline Portfolio) to 2,296 afy or 39 percent. The overall weighted criteria score
of this portfolio is 3.06 as shown in green in Figure 5.15.
Both portfolios involving DPR, Portfolios E and G, are contingent on the Valley Water option to Transfer,
which is anticipated to be resolved in 9 years. Once it is known whether Valley Water will exercise its
option to transfer RWQCP treated effluent, Palo Alto would likely know more information about whether
Valley Water would build a DPR Regional Facility (rather than an IPR Regional Facility). If so, Palo Alto may
want to explore the feasibility of the DPR Regional Facility option.
Another relatively high-scoring portfolio not dependent on the Valley Water Transfer is Bay Water
Desalination Portfolio C, with an overall weighted criteria score of 2.91. Although this portfolio does not
depend on whether Valley Water exercise its option to transfer a portion of RWQCP effluent, Portfolio C
(Enhanced Conservation with Bay Water Desalination) has a high capital cost, and high operating cost that
would itself take more than a decade to permit and build. Because of these cost and time considerations,
Palo Alto would likely explore this option once it is known whether Valley Water will exercise its transfer
option and if Palo Alto explores the DPR Regional Facility option and finds that it is not feasible.
Except for the Baseline Portfolio A, the lowest scoring portfolio that is independent on the decision of
Water Valley to transfer treated effluent is Portfolio D (Enhanced Conservation with Groundwater) with
an overall weighted criteria score of 2.78. This portfolio does score higher than the baseline primarily
because it increases reliability. This portfolio has a higher unit cost (and lower capital cost) and would
reduce the unplanned supply gap from 3,764 afy (Baseline) to 2,417 afy with a faster implementation
timeline than the two DPR options. However, because of the high weighted unit cost of this portfolio both
now ($2,556/af) and growing in the future to an estimated $5,330/af, Palo Alto would likely wait to explore
this option once it is known if Valley Water will exercise its transfer option and also if the higher scoring
DPR options are not feasible.
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5.6 Sensitivity and Scenario Analysis
A sensitivity analysis was conducted to identify how or if the findings change when the evaluation criteria
are weighted differently. In addition, the sensitivity analysis evaluates the portfolios under other supply
and demand scenarios and under different RWS Supply cutback conditions and different Water Shortage
Contingency Plan Stages.
Table 5.8 summarizes the criteria and sub-criteria weighting used in the sensitivity analysis. The sensitivity
analysis changes the criteria weighting in one criterion at a time, and all other criteria are adjusted
proportionally to isolate the intended effect. The results of the sensitivity analysis are then compared as a
final score across the range of weighted scorings. The findings of the sensitivity to the assumptions for the
key criteria are described in the following subsections, while the results for all criteria and weighting
percentages listed in Table 5.8 are included in Appendix E.
Table 5.8 Range of Criteria Weighting in Sensitivity Analysis
Criteria / Sub-Criteria Initial Weighting Lower Weighting Higher Weighting
50%Unit Cost 20%
35%
30%
10%
10%
10%
15%
5%
5%
20%
15%
5%
Reliability 50%
Environmental Benefit (total)
Efficient Use of Water
Ecological Benefit
45%
15%
5%15%
Ecological Benefit 5%15%
Ease of Implementation (total)
Implementation Timeline
Operational Complexity
Public Acceptance
0%30%
0%10%
5%0%10%
5%0%10%
5.6.1 Unit Cost Criterion
Figure 5.16 compares the results of the sensitivity analysis for the unit cost criterion for each portfolio. The
sensitivity analysis adjusts the unit cost weighting from 20 percent (shown in grey bars) to 5 percent in the
lower weighting scenario (green bars) and 50 percent in the higher weighting scenario (blue bars).
As shown, Portfolio E (Enhanced Conservation Phase 1 and 2 with Palo Alto DPR) has the most robust
results, with the highest score under the baseline scoring (3.43) as well as with lower (3.41) weighting of
the unit cost criterion, while Portfolio B (Enhanced Conservation Phase 1 and 2) has the highest score with
the higher unit cost criterion weighting. Among the options available to Palo Alto if Valley Water exercises
its option to transfer a portion of treated effluent from the RWQCP, Portfolio G (Enhanced Conservation
Phase 1 and 2 with Regional DPR) has the highest score under the initial scoring (3.06), while Portfolio C
(Enhanced Conservation Phase 1 and 2 with Bay Water Desalination) has the highest score (3.27) under
the lower weighting, and Portfolio B has the highest score (3.70) under the higher weighting. Portfolio B is
the lowest cost portfolio and Portfolio C is the highest cost portfolio. These portfolios are more sensitive
to changes in the weighting of the unit cost criterion.
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Figure 5.16 Results of Sensitivity Analysis for Unit Cost Criterion
5.6.2 Reliability Criterion
The results of the sensitivity analysis for the reliability criterion are compared for each portfolio in
Figure 5.17 . The sensitivity analysis adjusts the initial weighting from 35 percent (shown in grey bars) to
20 percent in the lower weighting scenario (green bars) and 50 percent in the higher weighting scenario
(blue bars). The results are shown in Figure 5.17 .
As shown, Portfolio E (Enhanced Conservation Phase 1 and 2 with Palo Alto DPR) has the most robust
results, with the highest overall score under the initial scoring (3.43) as well as with lower (3.30) and higher
(3.55) weighting of the unit cost criterion. Among the options available if Valley Water exercises the
option to transfer a portion of treated effluent from the RWQCP, Portfolio G (Enhanced Conservation
Phase 1 and 2 with Regional DPR) has the highest score under the baseline scoring (3.06), while Portfolio
B (Enhanced Conservation Phase 1 and 2) has the highest score (3.20) with the lower weighing, and
Portfolio C has the highest score (3.19) with the higher weighting. As Portfolio C has a larger reliability
score and Portfolio B has a lower reliability score, these portfolios are, therefore, sensitive to changes in
the weighting of the unit reliability criterion.
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Figure 5.17 Results of Sensitivity Analysis for the Reliability Criterion
5.6.3 Environmental Benefit Criterion
The sensitivity analysis for the Environmental Benefit criterion adjusts the weighting from 30 percent to
15 percent in the lower weighting scenario and to 45 percent in the higher weighting scenario. This
includes adjusting each of the three sub-criteria from 10 percent to 5 percent in the lower weighting and
15 percent in the higher weighting. Portfolio E (Enhanced Conservation Phase 1 and 2 with Palo Alto DPR)
has the most robust results with the highest score under all weighing scenarios. For the options available
if Valley Water exercises the option to transfer a portion of treated effluent from the RWQCP, Portfolio G
(Enhanced Conservation Phase 1 and 2 with Regional DPR) has the most robust results with the highest
score under all criteria weighting scenarios.
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Figure 5.18 Results of Sensitivity Analysis for the Environmental Benefit Criterion
5.6.4 Ease of Implementation Criterion
The sensitivity analysis for the ease of implementation criterion adjusts the weighting of the ease of
implementation criteria from 15 percent to 0 percent in the lower weighting scenario and 30 percent in
the higher weighting scenario. This includes adjusting each of the three sub-criteria from 5 percent to
0 percent in the lower weighting and 10 percent in the higher weighting. Portfolio E (Enhanced
Conservation Phase 1 and 2 with Palo Alto DPR) has the most robust results with the highest score under
all weighing scenarios. For the options available if Valley Water exercises the option to transfer a portion
of the treated effluent from the RWQCP, Portfolio G (Enhanced Conservation Phase 1 and 2 with Regional
DPR) has the most robust results with the highest score under all weighting scenarios.
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Figure 5.19 Results of Sensitivity Analysis for the Ease of Implementation Criterion
5.6.5 Demand Scenario
The sensitivity analysis was also conducted for two other demand projections, a high demand, and a low
demand. Portfolio E (Enhanced Conservation Phase 1 and 2 with Palo Alto DPR) had the highest score
under all demand scenarios. For the options available if Valley Water exercises the option to transfer a
portion of the treated effluent from the RWQCP, Portfolio G (Enhanced Conservation Phase 1 and 2 with
Regional DPR) had the highest score in all demand scenarios. Hence, it can be concluded that the
portfolio analysis results are not sensitive to the demand assumptions.
5.6.6 RWS Supply Cutback and Shortage Stage Scenarios
In addition to the multi-criteria scoring, the added supply reliability of each portfolio varies based on the
severity of the RWS Supply cutback and the water shortage stage. Palo Alto has six water shortage stages
in the Water Shortage Contingency Plan – Stages I through VI that are designed to achieve water savings
of up to 10 percent, 20 percent, 30 percent, 40 percent, 50 percent, and greater than 50 percent.
Table 5.9 summarizes the unplanned supply gap volumes for each portfolio for the 50 percent RWS
Supply cutback with the Shortage Stage II from Palo Alto’s Water Shortage Contingency Plan (as
discussed in Section 5.2). Table 5.9 also summarizes supply gaps from each portfolio at a Shortage Stage
III (more severe water conservation mandates) from Palo Alto’s Water Shortage Contingency Plan and a
30 percent RWS Supply cutback (less severe conditions).
As shown, none of the portfolios would avoid an unplanned supply gap during a 50 percent RWS Supply
cutback with a Shortage Stage II drought restrictions, with supply gaps from 3,764 afy for the baseline
portfolio to 852 afy for Portfolio C (Enhanced Conservation Phase 1 and 2 with Bay Water Desalination).
However, if Palo Alto imposes Shortage Stage III during a 50 percent RWS Supply cutback, or if the
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cutback was limited to 30 percent, three of the six portfolios would provide sufficient local supply capacity
to avoid an unplanned supply gap.
Table 5.9 Unplanned Supply Gaps under RWS Supply Cutback and Emergency Shortages
Unplanned Supply Gap (afy)
50% RWS Supply 50% RWS Supply 30% RWS SupplyPortfoliosCutback & Cutback & Cutback &
Shortage Stage II Shortage Stage III Shortage Stage II
A. Baseline 3,764
3,092
852
2,509
1,838
0
1,255
852
0
B. Enhanced Conservation Phase 1 and 2
C. Enhanced Conservation with Bay Water Desalination
D. Enhanced Conservation with Groundwater
E. Enhanced Conservation with Palo Alto DPR
F. Enhanced Conservation with IPR
2,417
967
1,163
0
627
0
1,032
2,296
0 0
G. Enhanced Conservation with Regional DPR 1,042 410
Increasing supply reliability generally comes at an increasing cost. However, some combinations of
options are clearly more cost effective than others. Portfolio E (Enhanced Conservation Phase 1 and 2 with
Palo Alto DPR) would be the lowest cost and best scoring portfolio of these three, while Portfolio C
(Enhanced Conservation Phase 1 and 2 with Bay Water Desalination) would be the most expensive
portfolio while Portfolio F (Enhanced Conservation Phase 1 and 2 with Palo Alto IPR) scores in between.
With a 30 percent cutback of RWS Supply, together with Shortage Stage II implementation in Palo Alto,
the total supply shortfall is eliminated completely for Portfolios C, E, and F, while a smaller supply deficit
remains for Portfolios A, B, D, and G as shown in Figure 5.20. Additional details for the sensitivity analysis
can be found in Appendix E.
Figure 5.20 Dry Year Supply and Demand Analysis by Portfolio for 2045 with a 30 percent RWS Supply Cutback
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5.7 Conclusions
In addition to the summary observations described in Section 5.5, there are several key conclusions from
the sensitivity analysis. As there are many variables at play, the conclusions can be separated in the
portfolio scoring results, supply reliability, and implementation considerations.
5.7.1 Scoring Results
Portfolio E (Enhanced Conservation with Palo Alto DPR) scored the highest in the event that Valley Water
does not exercise its option to transfer a portion of RWQCP treated effluent. The sensitivity analysis
showed this portfolio remains the top-scoring portfolio regardless of changes in cost or reliability criteria
and usually outperforms other portfolios. The only case where Portfolio E (Enhanced Conservation with
Palo Alto DPR) is not the portfolio with the highest weighted criteria score is when unit cost has additional
weighting. There, Portfolio B (Enhanced Conservation Phase 1 and 2) becomes the highest scoring
portfolio, and the baseline portfolio scores lower (3.37) but very close to Portfolio E (3.45). In that case, the
Palo Alto DPR facility is still the most favorable infrastructure investment compared with the other local
supply options; however, considering the cost of the facility relative to other benefits, Palo Alto may want
to continue with business as usual or implement enhanced conservation measures instead.
Portfolio G (Enhanced Conservation with Regional DPR) scores the highest if Valley Water does exercise
the option to transfer a portion of treated effluent from the RWQCP. However, if unit cost is weighted less
heavily and supply reliability is weighted more heavily, Portfolio C (Enhanced Conservation with Bay Water
Desalination) scores higher than Portfolio G if Valley Water exercises the option to transfer a portion of
treated effluent from the RWQCP.
If unit cost is given additional weight, Portfolio C (Enhanced Conservation with Bay Water Desalination)
scores lower than all other options, including Baseline Portfolio A, while Portfolio B (Enhanced
Conservation Phase 1 and 2) is the top-scoring portfolio and Portfolio G (Enhanced Conservation with
Regional DPR) is the top scoring supply infrastructure portfolio. This result is also sensitive to changes in
the Reliability criteria weighting. With a lower Reliability criteria weighting, Portfolio B (Enhanced
Conservation Phase 1 and Phase 2) is the top-scoring portfolio, while with a higher Reliability weighting,
Portfolio C (Enhanced Conservation with Bay Water Desalination) is the top-scoring portfolio if Valley
Water does not exercise the option to transfer a portion of treated effluent from the RWQCP.
The top scoring portfolios remain the same regardless of changes in Environmental Benefits or Ease of
Implementation criteria: Portfolio E if Valley Water does not exercise the option to transfer a portion of
treated effluent from the RWQCP and Portfolio G if Valley Water does exercise the transfer option. The
portfolio evaluation results are also not sensitive to the demand assumptions.
5.7.2 Supply Reliability
With an assumed 50 percent RWS Supply cutback and implementation of Shortage Stage III (up to
30 percent demand mandatory demand reduction), three portfolios provide sufficient local water supply
to avoid an unplanned supply gap - Portfolio E (Enhanced Conservation Phase 1 and 2 with Palo Alto
DPR), is the lowest cost and best scoring portfolio of these three, while Portfolio C (Enhanced
Conservation Phase 1 and 2 with Bay Water Desalination) is the most expensive portfolio and the only
portfolio of the three that can be implemented if Valley Water exercises the option to transfer a portion of
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treated effluent from the RWQCP, while Portfolio F (Enhanced Conservation Phase 1 and 2 with Palo Alto
IPR) scores in between.
5.7.3 Implementation Considerations
As an implementation consideration, the City plans to make the necessary improvements to convert two
additional emergency wells to active stand-by mode for use during drought emergencies. This will allow
the City to blend groundwater with RWS Supply during severe droughts only. In addition, improvements
to the City’s groundwater-related infrastructure will provide benefits even if the City pursues other supply
options in the future. The City will be able to use groundwater on a regular basis or as a supplemental
supply during emergencies or in a portfolio that includes a water reuse or desal option, if sized at a
smaller capacity that assumed in this OWP.
Additionally, as an implementation consideration, if Palo Alto plans to implement Conservation Phase 1
and 2. Additional analysis and exploration of the feasibility, staffing and cost of the measures included in
these Phases and refinement of those measures may be needed.
For IPR, DPR, and the Bay Water Desalination options, Palo Alto would need to develop and implement
community outreach strategies to achieve public acceptance. Although IPR regulations have been
adopted in California for over a decade, and IPR projects have been widely implemented across California
and other places in the US and the world, this supply option would be new to Palo Alto's customers.
Before moving forward with a project that would involve IPR, it would be customary to conduct a
community engagement campaign to gather information about public concerns and gauge the level of
public acceptance for IPR.
Similarly for Bay Water desalination, although Desalination has been implemented at various locations in
California for decades and ocean desalination is widely implemented across the US and the world, Bay
Water Desalination would be new to the customers of Palo Alto. Before moving forward with a project
that would involve Ocean Desalination or IPR, it would be customary to conduct a community
engagement campaign to gather information about public concerns and gauge the level of public
acceptance for Ocean Desalination or IPR. Considering that SFPUC is planning efforts for DPR options,
there may be opportunities to collaborate with SFPUC, BAWSCA and others to develop a regional
stakeholder engagement and community outreach program. Benefits could include but are not limited to
cost saving due to economies of scale, sharing of resources, levering technical and engagement expertise,
and minimizing stakeholder fatigue and confusion if multiple parallel efforts would be launched in the
same geographic area for similar topics and projects.,
Since the California DPR regulations were only recently adopted in December 2023, there are no active
DPR projects yet in the state of California. However, DPR has been implemented in other states (e.g., Texas
since 2014) and other parts of the world (e.g., Namibia since 1968). Before implementing DPR, this option
would be considered very innovative in California at this time; it is likely that the City would first conduct a
broad community engagement campaign to gather information about public concerns and gauge the
level of public acceptance.
Chapter 6 describes the OWP recommendations and provides more details regarding implementation.
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CHAPTER 6 ONE WATER IMPLEMENTATION PLAN
This chapter begins by summarizing the prioritized water supply and conservation portfolios discussed in
Chapter 5. Next, a trigger-based implementation roadmap is presented to guide the City with
decision-making as conditions will continue to evolve in the future. This chapter concludes with specific
recommended implementation actions and next steps.
6.1 Prioritized Portfolios
This One Water Plan (OWP) analyzed seven portfolios (A-G) with different combinations of the highest
ranked water supply and conservation options (options) that are described in Chapter 3 and evaluated in
Chapter 4. Portfolio A (Baseline) represents the traditional “Do Nothing” or “Business as Usual” alternative,
exclusive of any new options. However, this baseline includes the City’s already-planned water
conservation measures aimed at achieving the targets set forth in the Making Conservation a California
Way of Life water use efficiency legislation. Portfolios (B-G) each include different combinations of
options. These six portfolios were each compared to the Baseline Portfolio (A).
As described in detail in Chapter 5, each portfolio was evaluated based on the four following evaluation
criteria:
.
.
.
Environmental Benefit is scored for three sub-criteria including Reduced Reliance on the Tuolumne
River, Efficient Use of Water and Ecological Benefits.
Unit Cost is scored based on the projected unit cost expressed in dollar per acre-foot ($/af) of each
portfolio using the capacity weighted unit cost of all options in the respective portfolio.
Reliability is scored based on results of the dry year supply analysis for each portfolio using the
unplanned supply gap expressed in acre-foot per year (afy) during a 50 percent reduction in water
deliveries to Palo Alto from the Regional Water System (RWS).
.Ease of Implementation is scored based on three sub-criteria: Implementation Timeline, Operational
Complexity, and Public Acceptance.
The raw portfolio scores for each of the evaluation criteria are multiplied by the criteria weighting to get a
weighted score for each portfolio. Additionally, a sensitivity analysis was conducted to identify the
portfolios that are especially sensitive to changes to the weighting of the evaluation criteria and other
supply and demand scenarios to confirm that the recommended portfolios are robust across a range of
future conditions as well as changes to community priorities and values.
A summary of the options included in each portfolio is presented in Table 6.1. The portfolios were
compiled in a progressive manner using the highest scoring options first (Enhanced Conservation Phase 1
and 2) and then adding the other supply options in order of the highest evaluation score, but also
considering the total additional supply needed to fill the projected remaining supply gap in 2045 under a
50 percent supply cutback scenario from the RWS and only implementing Stage II from the City’s Water
Shortage Contingency Plan. As all other options besides Enhanced Conservation are relatively large supply
projects, each portfolio only includes one additional option.
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Table 6.1 Overview of Options included in each Portfolio
Enhanced
Conservation
Phase 1 and
Phase 2
DPR withPortfolioRWS
Supply
Bay Water
Desalination
Ground Palo Alto Palo Alto Regional
water DPR IPR Facility
A. Baseline X
B. Enhanced Conservation Phase 1 and 2 X X
XC. Enhanced Conservation Phase 1 and 2
with Bay Water Desalination
D. Enhanced Conservation Phase 1 and 2
with Groundwater
E. Enhanced Conservation Phase 1 and 2
with Palo Alto DPR
F. Enhanced Conservation Phase 1 and 2
with Palo Alto IPR
X
X
X
X
X
X
X
X
X
X
X
X
X
G. Enhanced Conservation Phase 1 and 2
with Regional DPR X
Notes:
DPR = Direct Potable Reuse; IPR = Indirect Potable Reuse; RWS = San Franciso’s Regional Water System.
Table 6.2 summarizes the weighted portfolio scores, yield, and unit cost by portfolio in both 2023 and
2045 dollars. It should be noted that the Tool used for the portfolio analysis can also display the escalated
unit cost for any year between 2023 and 2045. As shown in Table 6.2, four (4) of the seven (7) portfolios
are not sensitive to the decision of Valleyas Water to exercise the option to transfer effluent. If exercised,
this would provide sufficient supply for the DPR with Regional Facility option included in Portfolio G.
However, if this option is not exercised, Palo Alto would retain sufficient wastewater effluent to implement
either the Palo Alto DPR of IPR options included in Portfolios E and F, respectively.
Table 6.2 Portfolio Evaluation Summary
Valley Water
Transfer Option
Exercised
Weighted
Portfolio
Score(1)
Yield (afy)Unit Supply Cost ($/af)
Portfolio Names Normal Dry 2023 2045
year year dollars dollars(2)
A. Baseline.not sensitive
not sensitive
2.55
2.92
0(1)0(1)$2,210
$2,075
$4,088
$3,903B. Enhanced Conservation Phase 1 and 2 1,342
5,823
1,342
C. Enhanced Conservation Phase 1 and 2
with Bay Water Desalination
D. Enhanced Conservation Phase 1 and 2
with Groundwater
E. Enhanced Conservation Phase 1 and 2
with Palo Alto DPR
F. Enhanced Conservation Phase 1 and 2
with Palo Alto IPR
not sensitive
not sensitive
only without
only without
only with
2.91
2.79
3.43
2.99
3.06
5,823
3,143
5,829
5,978
3,023
$3,854
$2,556
$2,645
$3,323
$2,355
$6,663
$5,330
$4,938
$6,440
$4,552
3,592
6,065
6,492
3,111G. Enhanced Conservation Phase 1 and 2
with Regional DPR
1) The weighted portfolio score in the Evaluation Tool is based on the portfolio weighted unit costs in 2045 dollars.
2) The Baseline Portfolio solely relies on imported water from the SFPUC via its RWS supply system, combined with already-planned water conservationprograms that are not included in the Enhanced Conservation measures as described in Chapter 3.
Figure 6.1 shows the weighted scores summarized in Table 6.2 with a breakdown of the different portfolio
evaluation categories. The unit cost and reliability scores are shown in red and blue, respectively, while the
three environmental benefit sub-criteria are shown in different shades of green. Similarly, the three ease
of implementation subcategories are shown in different shades of purple.
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Figure 6.1 Comparison of Weighted Portfolio Evaluation Scores.
As shown in Figure 6.1, all portfolios score higher than the Baseline, making the “Do Nothing” alternative
the least attractive portfolio based on the combined scores and the size of the projected supply shortfall
under various RWS cutback scenarios. Moreover, Portfolios B through G all included Enhanced
Conservation Phase 1 and Phase 2 because of the favorable individual option evaluation scores presented
in Chapter 4. Since Enhanced Water Conservation is beneficial in all conditions, it is a high priority to
develop further and implement. As such, both Enhanced Conservation Phase 1 and Phase 2 are included
in all portfolios except the Baseline (A).
Figure 6.1 also shows that Portfolio E (Enhanced Conservation with Palo Alto DPR) scores the highest, with
the added reliability being a major contributor to the overall score. However, this portfolio would only be
implemented if Valley Water decides not to exercise its option to transfer a portion of treated effluent
from the Regional Water Quality Control Plant (RWQCP). As it is anticipated that this decision will not be
until the end of 2032, Palo Alto could consider other portfolios in the interim that do not depend on this
decision.
The portfolio with the highest combined weighted score that is not dependent on Valley Water’s transfer
option decision is Portfolio B (Enhanced Water Conservation Phase 1 and 2), followed by Portfolio C
(Enhanced Water Conservation with Bay Water Desalination. The highest scoring portfolio if Valley Water
exercises the option to transfer a portion of treated effluent from the RWQCP is Portfolio G (Enhanced
Conservation with Regional DPR). This option is also dependent on Valley Water opting to build a
Regional DPR facility located in Palo Alto (rather than an IPR facility that is currently envisioned).
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In summary, the portfolios are prioritized based on the combined weighted multi-criteria scores and the
Valley Water transfer option decision as follows:
.
.
.
Portfolio B: Enhanced Conservation Phase 1 and 2 only (independent of Valley Water Transfer option
decision).
Portfolio E: Enhanced Conservation Phase 1 and 2 with the addition of a local Palo Alto DPR facility
(only feasible if Valley Water does not exercise the transfer option).
Portfolio G: Enhanced Conservation Phase 1 and 2 with the addition of a Regional DPR facility (only
feasible if Valley Water does exercise the transfer option and opts to build a Regional DPR facility
located in Palo Alto).
6.2 Trigger-Based Implementation
When prioritizing the options described in this OWP and compiled in the various portfolios, it is important
to acknowledge that many of the underlying planning assumptions and conditions present today are
likely to evolve and change over time. For example, the forecasted water demand presented in the
medium growth forecast may materialize faster or slower depending on economic, demographic, and
regulatory conditions. These types of changes should be monitored over time to adjust project
implementation timelines. However, these types of changes likely impact timing but not the choice
between two or more options. Events and conditions that can have an impact on the prioritization of
options are referred to as "triggers."
Due to the complexity and magnitude of the options identified and evaluation as part of this OWP, there
are several potential unforeseen conditions and trigger events. This means the proposed portfolios
presented herein should only be taken as preliminary and may change. Moreover, some options may
neither be feasible nor required under future circumstances. By identifying the primary trigger events for
the highest scoring options and portfolios, it is possible to create a trigger-based implementation
roadmap.
The two major triggers that were identified for this OWP that could impact the decision on moving
forward with one or more of the options are:
1. Need to Increase Supply Reliability
2. Valley Water Transfer Option
These triggers are described in the following subsections. It should be noted that funding is not included
as a trigger because sufficient funding is a common requirement for all projects. Although insufficient
funding can certainly postpone, downsize, or eliminate projects, it was decided that funding should be
considered as an implementation challenge rather than a trigger. Also important is public acceptance of
IPR, DPR, and Bay Water Desalination. The challenge of public acceptance of these water reuse and
desalination options exists whether or not Palo Alto elects to do any of the options considered in the
OWP. This is because the San Francisco Public Utilities Commission (SFPUC) is currently evaluating the
possibility of including DPR and/or Desalination in the RWS portfolio. Palo Alto plans to work
collaboratively and actively with both SFPUC and the Bay Area Water Supply and Conservation Agency
(BAWSCA) to incorporate messages and information about these topics into outreach materials.
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6.2.1 Trigger 1: Increase Supply Reliability
The decision on whether the City needs to further increase its supply reliability is contingent upon the
following key considerations:
1. The forecasted water demand is based on anticipated growth due to demographic changes,
development, real estate market conditions, economic factors, and regulatory conditions such as the
allowance of accessory dwelling units (ADUs) and/or parcel subdivisions.
2. The forecasted supply availability and reliability of imported water delivered by the SFPUC via its RWS.
The portfolio analysis presented in this OWP is based on a maximum cutback of 50 percent from Palo
Alto’s baseline allocation together with the implementation of Shortage Stage II from Palo Alto’s
Water Shortage Contingency Plan (WSCP), targeting a demand reduction of 10-20 percent. This is a
conservative assumption for the purpose of comparing the robustness of each of the portfolios to
drought. To illustrate the impact of this assumption, the changes in the projected supply shortfall with
both a 50 percent and a 30 percent cutback are shown in Table 6.3.
3. The City’s existing water conservation program, thus excluding the Enhanced Conservation measures
of this OWP, is projected to decrease water demands of the City’s service population in 2020 by
approximately 500 afy in 2045 (Palo Alto, 2021). If these measures result in either more or less water
use reduction, the projected remaining supply gap under the assumptions mentioned above would
decrease or increase, respectively. Hence, the success of the ongoing water conservation program will
impact the City’s need to increase water supply reliability.
4. The implementation of one or more local water supply options, such as the options evaluated in this
OWP, would decrease the magnitude and risk of a potential supply shortfall.
The combination of these factors described above needs to be considered in the trade-off decision
process to determine if the City needs to increase its water supply reliability with the addition of other
local options.
As shown in Table 6.3, the projected supply shortfall for the Baseline Portfolio is 3,764 afy during a
50 percent RWS cutback with implementation of Emergency Stage II. However, the unplanned supply gap
is estimated to be reduced to 2,509 afy with the implementation of Stage III or to 1,255 afy if the RWS
cutback was limited to 30 percent. Moreover, it can be concluded that none of the other portfolios (B-G)
would avoid an unplanned supply gap during a 50 percent RWS cutback with an Emergency Shortage
Stage II. However, if Palo Alto imposed Emergency Shortage Stage III during a 50 percent RWS supply
cutback, or if the cutback were limited to 30 percent, three of the six portfolios would provide sufficient
local supply capacity to avoid a supply shortfall. Hence, the trigger question “Does the City need to
increase its supply reliability?” is strongly dependent on the type and duration of a potential RWS cutback,
which the City aims to prepare for.
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Table 6.3 Projected Unplanned Supply Gap under various RWS Cutback and Shortage Scenarios
Projected Remaining Unplanned Supply Gap (afy)
Portfolios 50% RWS cutback 50% RWS cutback 30% RWS cutback
& Stage II
3,764
3,092
852
& Stage III & Stage II
A. Baseline 2,509
1,838
0
1,255
852
0
B. Enhanced Conservation Phase 1 and 2
C. Enhanced Conservation with Bay Water Desalination
D. Enhanced Conservation with Groundwater
E. Enhanced Conservation with Palo Alto DPR
F. Enhanced Conservation with IPR
2,417
967
1,163
0
627
0
1,032
2,296
0 0
G. Enhanced Conservation with Regional DPR 1,042 410
6.2.2 Trigger 2: Valley Water Transfer Option
Per the agreement dated November 18, 2019 (Palo Alto 2019c), the Valley Water Effluent Transfer Option
involves a contractual obligation for Palo Alto and Mountain View to transfer a minimum flow delivery of
an annual average of 9 mgd of effluent from the RWQCP to Valley Water. The agreement provides Valley
Water 13 years (from 2019 to 2032) to decide whether to exercise the Effluent Transfer Option. If Valley
Water exercises the option, Valley Water may elect to develop a Regional Purification facility to purify the
water and use it for beneficial use in Santa Clara County south of Mountain View. A final decision is not
anticipated until 2032.
Table 6.2 summarizes the weighted portfolio scores, yield, and unit cost by portfolio in both 2023 and
2045 dollars. It should be noted that the Tool used for the portfolio analysis can also display the escalated
unit cost for any year between 2023 and 2045. As shown in Table 6.2, four (4) of the seven (7) portfolios
are not sensitive to the decision of Valley Water to exercise the option to transfer effluent. If exercised,
this would provide sufficient supply for the DPR with the Regional Facility option included in Portfolio G.
However, if this option is not exercised, Palo Alto would retain sufficient wastewater effluent to implement
either the Palo Alto DPR or IPR options included in Portfolios E and F, respectively.
Table 6.2, four of the seven portfolios are not impacted by the execution of Valley Water’s transfer option
under this agreement because the options included in these portfolios can be implemented with or
without the Valley Water Transfer in place. However, the following options and portfolios are dependent
on this trigger as follows:
.Palo Alto DPR in Portfolio E (Enhanced Conservation with Palo Alto DPR). This portfolio can only be
implemented if Valley Water does not exercise the Effluent Transfer Option as the transfer would limit
the amount of wastewater flows still available for reuse to approximately 1.9 mgd by 2045, including
redirecting permanent dewatering flows. If Valley Water exercises the Effluent Transfer Option, this
portfolio would not be feasible. Hence, the Palo Alto DPR option should only be set in motion once
Valley Water makes a final decision to not exercise the Effluent Transfer Option.
.Palo Alto IPR in Portfolio F (Enhanced Conservation with Palo Alto IPR). Similar to Palo Alto DPR, this
portfolio can only be implemented if Valley Water does not exercise the Effluent Transfer Option.
Although the addition of up to 3,000 afy of groundwater in the IPR option would allow for a larger
project than the Palo Alto DPR option, it was concluded that if Valley Water exercises the Effluent
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Transfer Option, this portfolio would not be feasible. Hence, the Palo Alto IPR option should only be
set in motion once Valley Water makes a final decision to not exercise the Effluent Transfer Option.
.Regional DPR in Portfolio G (Enhanced Conservation with Regional DPR). This portfolio can only be
implemented if the Valley Water Effluent Transfer Option is exercised, and Valley Water builds a
regional DPR facility located in Palo Alto. Palo Alto should maintain close communication and
partnership with Valley Water to be aware of Valley Water’s plans. This approach would allow Palo
Alto to advance a water supply option if a beneficial solution can be developed in partnership with
Valley Water’s Regional Purification facility.
Implementation of water supply projects and water conservation programs typically requires broad public
support, especially projects involving significant investments of rate payers’ money, new construction, the
use of new treatment technologies for the existing customer base, potential changes in water quality
characteristics, potential environmental impacts, among other factors. Regardless of whether Palo Alto
considers IPR, DPR, or desalination options, it is essential to develop outreach strategies to gain public
acceptance. Unique conditions for IPR, DPR, and Desalination are addressed in Chapter 5 section 5.7.3
Implementation Considerations.
6.3 Trigger-Based Implementation Roadmap
A trigger-based implementation roadmap was developed to guide the City of Palo Alto with prioritization
and the decision-making processes for future option implementation. These options are all new local
water supply concepts and new water conservation measure concepts. No action or decision is being
recommended at this time regarding the implementation of any of these options. The purpose of
identifying these options is to increase local supply reliability in the event of a prolonged outage or
reduction in imported water deliveries from the RWS. Should one of these conditions arise, the options
can be further evaluated as needed.
The One Water Plan (OWP) screened 27 options through a two-step process (pre-screening and screening
as described in Chapter 3) and used this process to narrow the options to 15. The OWP then evaluated the
remaining 15 options against four evaluation criteria and this process narrowed the options to seven for
inclusion in portfolios (Chapter 4 provides a detailed description of the evaluation criteria and option
evaluation). The OWP also evaluated the portfolios against the evaluation criteria to select the highest-
scoring portfolios (Chapter 5). Additionally, the City conducted workshops with City staff, stakeholder
meetings with community members and regional partners, and provided updates to the Utility Advisory
Commission (UAC). Although some of the options did not score favorably at this time under the current
screening and evaluation criteria, it should be noted that such options may be viable if conditions change.
The implementation of the options and/or portfolios described in this OWP is also dependent on the
occurrence of certain triggers. To guide the City’s future decision-making, a trigger-based implementation
roadmap was developed, which is graphically depicted in Figure 6.2.
As shown in Figure 6.2, the trigger-based implementation roadmap follows a pathway indicated by the
blue arrows pointing to triggers described in Sections 6.2.1 and 6.2.2, leading to trigger decisions that are
shown as orange diamonds. Each trigger is a key decision point that leads to different pathways
depending on the answer to the trigger question with either a YES or NO. Note that in reality, the answers
are not binary, and some grey areas will exist.
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Figure 6.2 Trigger-Based Implementation Roadmap
1. The “Increase Supply Reliability?” trigger occurs multiple times in the pathway as the City may want to
revisit this decision after implementing new options to verify if the City’s total supply portfolio meets
the reliability goal needs or if additional local water supplies are needed. The new local supply and
conservation options are depicted in blue boxes. The sequence of the options along the pathway
reflects the portfolio evaluation findings presented in Chapter 5.
The triggers and pathways of decisions regarding these options are depicted in Figure 6.2. As noted
earlier, this trigger-based implementation roadmap is a simplified version of many decisions, and
priorities can change in the future as the underlying conditions, assumptions, and triggers evolve over
time. Additionally, other triggers, such as land availability and political will, are likely part of the
decision-making process. Moreover, multiple triggers can change at the same time, opening a variety of
pathways.
Despite its simplification, the purpose of the trigger-based implementation roadmap is to lead the City to
the options with the highest scores first, followed by lower scoring options. As triggers and conditions
such as technological advancements and cost escalation rate of the groundwater production charge (GPC)
can change priorities, it is critical that the city reconsider the benefits of all options that are impacted by
these changes when deciding to move forward with the implementation of any of these options. For
example, technological advancements in both treatment technologies and energy efficiency would make
all options involving advanced treatment score higher and possibly more attractive than options that
score higher at the time of this OWP development.
CITY OF PALO ALTOONE WATER PLAN 6-8
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OCTOBER 2024 / FINAL / CAROLLO
6.3.1 Enhanced Conservation Phase 1 and Phase 2
Water conservation measures included in Enhanced Conservation Phase 1 result in a higher weighted
criteria score and lower unit cost ($323/af) than the measures included in Phase 2 ($1,939/af). The OWP
concluded that Enhanced Conservation measures could be implemented in phases, such that the City
would start with adding the Phase 1 water conservation measures that are estimated to cost less and are
generally considered easier to implement, before adding the Phase 2 measures. These water conservation
measures are described in detail in Chapter 3, while the gradual increase to the projected combined yield
of 1,332 afy over time is shown in Figure 6.3. These enhanced water conservation measures are in addition
to the ongoing water conservation program activities aimed to reduce per capita water use to comply
with the statewide regulation for “Making Water Conservation a California Way of Life” (DWR, 2017).
Figure 6.3 Projected Yield Trajectory of Enhanced Conservation Phase 1 and 2.
6.3.2 Groundwater
As the combined yield of the Enhanced Water Conservation Phase 1 and 2 is estimated to be 1,332 afy
once all measures have reached the full saturation, this option would not be sufficient to meet the
projected remaining supply gap of 3,764 afy under a 50% RWS cutback and Stage II shortage scenario
(see Table 6.3).
Knowing the City is planning to implement the option to blend groundwater with RWS supply during
emergencies, if the answer to the “Increase Supply Reliability?” trigger question remains YES, the next
recommended option involving groundwater would be to install Iron, Manganese, and Total Dissolved
Solids treatment at two of the City’s existing emergency supply groundwater wells to repurpose the wells
for regular potable use as described in Portfolio D (Enhanced Conservation and Groundwater). Continuous
operation of the groundwater wells would require treatment to improve the taste and odor of the water
to the level Palo Alto customers are accustomed to (see the groundwater treatment options discussed in
Chapter 3). This option is estimated to yield 2,250 afy. The Valley Water groundwater production charge
would apply to each unit of groundwater pumped.
CITY OF PALO ALTOONE WATER PLAN 6-9
CHAPTER 6
OCTOBER 2024 / FINAL / CAROLLO
6.3.3 Direct Potable Reuse Options
If the City decides that public acceptance for a local DPR project would be achievable with a community
engagement and education campaign, the status of Valley Water’s decision on whether to exercise the
Effluent Transfer Option will determine which type of DPR project is most beneficial and cost-effective for
the City.
1. If Valley Water does not exercise the Effluent Transfer Option, the City would have sufficient
wastewater flows to implement DPR with a Palo Alto Treatment Facility with an estimated yield of
4,723 afy under normal year conditions and 4,487 afy under dry year conditions. Hence, once this
project is in place, the City would have more than sufficient local supply to meet the unplanned
supply gap under a 50 percent RWS cutback and Shortage Stage II conditions. However, the capacity
of this option could potentially be reduced depending on the success of already planned and the
enhanced water conservation measures. Portfolio E (Enhanced Conservation and Palo Alto DPR) is the
top-scoring portfolio if Valley Water does not exercise the Effluent Transfer Option.
2. If Valley Water exercises the Effluent Transfer Option, Palo Alto would not have sufficient wastewater
flows to implement DPR with a Palo Alto treatment facility. In this case, if Valley Water also decides to
build a Regional DPR facility located in Palo Alto, working with Valley Water on a Regional DPR option
for Palo Alto, as described in Portfolio G, is the highest scoring portfolio. As described in Chapter 3,
the Regional DPR facility would have an estimated yield for Palo Alto of 1,769 afy under normal year
conditions and 1,681 afy under dry year conditions. Hence, once this project is in place and the
Enhanced Conservation Phase 1 and Phase 2 measures have reached saturation, the City would have
increased its local water supply by 3,111 afy, nearly enough local supply to meet a 3,764 afy remaining
supply gap.
6.3.4 Other Options
3. Although the other options involving IPR, Bay Water Desalination, and Groundwater Treatment scored
lower overall than the two DPR options, the City could also decide to implement any of these options
when conditions change. For example, if there is urgency to develop local water supplies while there is
uncertainty about whether Valley Water will exercise the Effluent Transfer Option, the implementation
priority of the other options is as follows based on the multi-criteria evaluation described in
Chapter 5:
1. Indirect Potable Reuse (Portfolio F with a weighted score of 2.99)
2. Bay Water Desalination (Portfolio C with a weighted score of 2.91)
3. Groundwater with Treatment (Portfolio D with a weighted score of 2.79)
The triggers and pathways of these options are depicted in Figure 6.2. As noted earlier, this trigger-based
implementation roadmap is a simplified version of many decisions, and it is likely that multiple pathways
can be chosen. By updating the underlying assumptions, cost estimates, and scoring periodically, the City
can use this trigger-based implementation roadmap concept for adaptive plan implementation.
The OWP considered all other water supply and conservation options and either pre-screened or screened
out those options through the process described in Chapter 3. Appendix B describes pre-screened out
options in more detail while Chapter 3 details options removed through the screening process. These
options include new irrigation wells, DPR with Palo Alto Facility and Small Salt Removal Facility,
CITY OF PALO ALTOONE WATER PLAN 6-10
CHAPTER 6
OCTOBER 2024 / FINAL / CAROLLO
Non-Potable Reuse with Phase 3 expansion, graywater capture and reuse, residential rainwater capture,
green stormwater infrastructure, and multi-source storage.
6.4 Next Steps
The One Water Plan presents a 20-year adaptable roadmap of prioritized options that provides an
achievable path toward meeting the City’s water supply and water conservation goals. When
implemented, the selected combination of options may mitigate the impact of future water supply
uncertainties such as severe multi-year drought or changes in climate, water demand, and regulations. As
stated in Chapter 1, the two main work products of the OWP effort are 1) the OWP document, and 2) an
Excel-based tool that can be used to evaluate and prioritize water supply and water conservation
portfolios now and as future uncertainties are resolved.
The City is already planning the following activities:
1. Continue with planned water conservation program activities to meet the Making Conservation a
California Way of Life water use efficiency targets.
2. Make the necessary improvements to get the two emergency groundwater wells (El Camino Well and
Eleanor Park Well) on active stand-by mode with proper valving, controls, and blending equipment for
use during droughts and/or emergencies. These improvements would allow the City to operate the
groundwater wells concurrently with RWS water supply as future conditions warrant.
3. Continue to monitor external funding opportunities from Federal, State, or Local grant funding and
loan programs that could provide an opportunity to make any of the supply and conservation options
more affordable.
4. Continue to coordinate with BAWSCA, SFPUC, and Valley Water regularly to learn from their outreach
and education efforts about the public acceptance of water reuse options and desalination options.
The OWP recommends the following actions to enhance the City’s water supply reliability that reflect the
priorities of the City, as well as the input received from regional partners and the community during the
stakeholder engagement process utilities for the development of this Plan:
1. Start with the planning and exploration of the Enhanced Water Conservation measures included in
Phase 1 including but not limited to the following:
a. Outdoor Irrigation Efficiency for Commercial, Industrial, or Institutional (CII) Properties.
b. 3-Day Watering Week.
c. Non-Functional Turf Ban for CII Properties.
d. Lawn Limitation for New Development and Major Retrofits.
e. Low-Income Residential High Efficiency Toilet (HET) Replacement Program.
2. Once the Enhanced Conservation Phase 1 program activities are set in motion, start with the planning
and exploration of the Enhanced Conservation Phase 2 measures, namely:
a. Lawn Limitation for Residential Properties upon Resale.
b. HET Replacement Program for CII Properties.
c. City Landscaping Support for Turf Replacement.
CITY OF PALO ALTOONE WATER PLAN 6-11
CHAPTER 6
OCTOBER 2024 / FINAL / CAROLLO
3. Incorporate education and monitoring of the level of support for IPR, DPR, and/or Bay Water
Desalination in Palo Alto’s community outreach and engagement activities in close collaboration with
SFPUC, BAWSCA, and other regional agencies and neighboring agencies.
4. Update the option cost estimates, and Excel-based Evaluation Tool assumptions as new information
becomes available and periodically update the portfolio analysis to confirm or adjust the
trigger-based roadmap implementation plan.
5. Prepare a conceptual feasibility study for the DPR, IPR, Bay Water Desalination, and/or Groundwater
Treatment option(s) once there is more clarity on which of these larger supply options may be
implemented in the future (if any). A feasibility study could include, but is not limited to:
.Facilities Planning: Conduct a more detailed technical analysis to size infrastructure components,
develop treatment process options, prepare conceptual site plans, identify land acquisition or lease
agreement needs, and develop a list of special studies required to further advance the project, such as
geotechnical, hydrogeological, and water quality analysis to name a few.
.
.
Cost Estimating: Utilizing the additional information from the facilities planning, refine cost estimates
to a Class 5 level (-50% or +100%) or Class 4 level (-10% to +30%) as appropriate.
Funding and Financing: Identify potential Federal, State, and Local funding and grant options.
Evaluate/prioritize these options and decide on the timeline to apply for the most attractive programs,
considering the timelines to obtain and use the funds, administration cost, and overall
competitiveness.
.
.
Inter-agency Agreements: Depending on the option, one or more inter-agency agreements may be
needed for the use/discharge of flows, brine discharges, energy use, land easements, collaborative
stakeholder/community engagement program(s), etc.
Environmental Documentation Needs: Based on the facilities planning effort, identify the
appropriate environmental documentation pathway under the California Environmental Quality Act
(CEQA) and/or National Environmental Policy Act (NEPA). Bigger projects likely require a full
Environmental Impact Report (EIR) or could be bundled in a Programmatic EIR under CEQA.
Moreover, identify the potential stakeholders that need to be engaged early to avoid potential delays,
prepare an overall timeline for the Environmental Documentation process as this can span multiple
years and obtain a budget estimate to incorporate in the funding strategy.
.Permitting Needs: Based on the facilities planning effort, identify the appropriate permits that are
likely required from local and state agencies, such as the State Water Resources Control Board
(SWRCB), including the Division of Drinking Water (DDW) as well as other agencies like the San
Francisco Bay Regional Water Quality Control Board (RWQCB), California Department of Fish and
Wildlife (CDFW), and Caltrans as applicable. Identify the essential documentation needed to start the
permitting process and develop an approximate timeline and budget estimate to obtain the most
critical permits.
.Stakeholder and Community Outreach: Based on the City’s understanding of the level of support
for the proposed project from the ongoing educational and monitoring activities, it may be prudent
to develop and implement a dedicated community engagement campaign, possibly in collaboration
with Valley Water, BAWSCA and/or SFPUC.
CITY OF PALO ALTOONE WATER PLAN 6-12
OCTOBER 2024 / FINAL / CAROLLO
APPENDIX A REFERENCES
CITY OF PALO ALTOONE WATER PLAN APPENDIX A
APPENDIX A
OCTOBER 2024 / FINAL / CAROLLO
APPENDIX A REFERENCES
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Operator Should Know. Information obtained in June 2023.
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t%20Sheet.pdf
(B&V, 2021)
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Black and Veatch, Advanced Water Purification System - Basis of Design Report,
Prepared for the City of Palo Alto. November 2021.
Brown and Caldwell, Countywide Water Reuse Master Plan (CoRe Plan). Prepared for
Valley Water, June 2021.
(Carollo, 2000)Carollo Engineers, 2000. Long Term Water Supply Plan. Prepared for the City of Palo
Alto. May 2000.
(Carollo, 2018a)
(Carollo, 2018b)
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Carollo Engineers, Inc., One Water LA 2040 Plan prepared for the City of Los Angeles,
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Carollo Engineers, Inc., One Water 2050 Plan (Draft) prepared for the City of South
Pasadena, CA. November 2021
Carollo Engineers, Countywide Potable Reuse Study prepared for the City of Santa
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(Carollo, 2023b)
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Carollo Engineers, Inc., Water, Recycled Water, and Wastewater Master Plan Updates
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generation-research_.html.
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Maddaus Water Management, Inc., in collaboration with Brown and Caldwell (B&C) and
Western Policy Research. Regional Water Demand and Conservation Projections Update.
Draft. Prepared for Bay Area Water Supply & Conservation Agency (BAWSCA)
November 17, 2022
CITY OF PALO ALTOONE WATER PLAN A-1
APPENDIX A
OCTOBER 2024 / FINAL / CAROLLO
(NOAA, 2018)
(OSHA, 2023)
National Oceanic and Atmospheric Administration (NOAA) Climate Data Online: Palo
Alto Rainfall Data from 2000 to 2018.
Occupational Safety and Health Administration Standard Number 1910.141 –
Sanitation. Information obtained in June, 2023 https://www.osha.gov/laws-
regs/regulations/standardnumber/1910/1910.141#1910.141(c)(1)(i)
(Pacific Institute, 2020)Economic Evaluation of Stormwater Capture and its multiple benefits in California,
March 2020.
https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0230549
(Palo Alto, 2005)
(Palo Alto, 2006)
Palo Alto Monthly Wastewater Flows, July 2005.
Final EIR, City of Palo Alto Emergency Water Supply and Storage Project, SCH
#2006022038
(Palo Alto, 2008)City of Palo Alto, December 2008. Recycled Water Facility Plan.
https://www.cityofpaloalto.org/files/assets/public/v/1/utilities/water-
quality/final_palo_alto_rwmp_dec08.pdf
(Palo Alto, 2017)
(Palo Alto, 2018a)
City of Palo Alto, 2017. 2017 Water Integrated Resources Plan. January 2017.
City of Palo Alto, Feed to an Advanced Water Purification Facility. May 2018.
(Palo Alto, 2018b)City of Palo Alto, Graywater Laundry to Landscape Workshop.
https://www.valleywater.org/news-events/events/graywater-laundry-landscape-
workshop-palo-alto. December 2018.
(Palo Alto, 2018c)
(Palo Alto, 2018d)
City of Palo Alto, July 2018. Preliminary Design Report.
City of Palo Alto City Council Minutes, August 20, 2018.
https://www.cityofpaloalto.org/files/assets/public/v/1/agendas-minutes-
reports/agendas-minutes/city-council-agendas-minutes/00-archive/2018/08-20-2018-
final-ccm-minutes.pdf
(Palo Alto, 2019a)City of Palo Alto, Green Stormwater Infrastructure Plan. 2019
https://www.cityofpaloalto.org/files/assets/public/public-works/environmental-
compliance/stormwater-wpg/green-stormwater-infrastructure-
gsi/cpa_gsi_plan_document_2019_final_rev2_lr.pdf..
(Palo Alto, 2019b)
(Palo Alto 2019c)
City of Palo Alto, Wastewater service connection charges utility rate schedule s-5,
September 2019. https://www.cityofpaloalto.org/files/assets/public/v/1/utilities/rates-
schedules-for-utilities
City of Palo Alto, City Council Staff Report ID #10627, Water Reuse Agreement with
Valley Water, November 18, 2019.
https://www.cityofpaloalto.org/files/assets/public/v/1/agendas-minutes-
reports/reports/city-manager-reports-cmrs/year-archive/2019/id-10627-mini-packet-
11182019.pdf
(Palo Alto, 2021)
(Palo Alto, 2022a)
City of Palo Alto, 2020 Urban Water Management Plan and Water Shortage Contingency
Plan, June 2021.
https://www.cityofpaloalto.org/files/assets/public/v/1/utilities/uwmp/2020-uwmp_final-
submission-to-dwr.pdf
City of Palo Alto, 2022. Comprehensive Plan 2030. Adopted by City Council November
2017, amended December 2022.
CITY OF PALO ALTOONE WATER PLAN A-2
APPENDIX A
OCTOBER 2024 / FINAL / CAROLLO
https://www.cityofpaloalto.org/files/assets/public/planning-amp-development-
services/3.-comprehensive-plan/comprehensive-plan/full-comp-plan-2030_with-
dec19_22-amendments.pdf.
(Palo Alto, 2022b)City of Palo Alto,2023-2031 Housing Element, December 2022.
https://paloaltohousingelement.com/wp-content/uploads/2022/12/Palo-Alto-Housing-
Element-2023-2031.pdf
(Palo Alto, 2023a)
(Palo Alto, 2023b)
City of Palo Alto correspondence with Carollo. New DPR Option with SSRF, 6/23/2023
email from Lisa Bilir to Madison Rasmus.
City of Palo Alto, 2022 Sustainability and Climate Action Plan (S/CAP). Adopted by City
Council June 5, 2023.
https://www.cityofpaloalto.org/files/assets/public/v/1/sustainability/reports/2022-scap-
report_final.pdf
(Palo Alto,2023c)City of Palo Alto, 2023. Watershed Protection – Apply for a Rain Barrel Rebate.
https://www.cityofpaloalto.org/Departments/Public-Works/Watershed-
Protection/Stormwater-Rebates/Rain-Barrels. Last updated January 2023.
(Palo Alto, 2023d)
(Palo Alto, 2023e)
City of Palo Alto, Commercial wastewater collection and disposal utility rate schedule s-
2, July 2023f. https://www.cityofpaloalto.org/files/assets/public/v/5/utilities/rates-
schedules-for-utilities
City of Palo Alto, Historical Billing data on City Park Water Usage from 2018 to 2022.
January 2023.
(Palo Alto, 2023f)
(Palo Alto, 2023g)
(Palo Alto, 2023h)
(Palo Alto, 2023k)
City of Palo Alto, Addendum to Guaranteed Feed Memo. March 2023.
City of Palo Alto. Current and Projected SFPUC Supply Costs for Palo Alto, 2023.
City of Palo Alto, Waterfluence Data CII Savings. 2023
City of Palo Alto, Website information regarding the Rain Barrel Rebate. Information
obtained in June, 2023 https://www.cityofpaloalto.org/Departments/Public-
Works/Watershed-Protection/Stormwater-Rebates/Rain-Barrels
(Palo Alto, 2023l)
(Palo Alto, 2023m)
City of Palo Alto, Project correspondence with Carollo regarding project construction
bids for WMR 29 (June, 2023) and WMR 27 (June, 2019). 2023
City of Palo Alto, Website information regarding the Landscape Rebate Program.
Information obtained in June, 2023
https://www.cityofpaloalto.org/files/assets/public/v/1/utilities/bill-
inserts/landscape_ad_v01.pdf
(Palo Alto, 2023n)
(Palo Alto, 2024a)
City of Palo Alto, Staff Report 2308-1863 Approval of Financing Plan for Local Salt
Removal Facility at the Regional Water Quality Control Plant, October 16, 2023
https://cityofpaloalto.primegov.com/meeting/document/2844.pdf?name=Item%2010%
20Staff%20Report
City of Palo Alto, Website information regarding Smart Metering Program. Information
obtains in January 2024.
https://www.cityofpaloalto.org/Departments/Utilities/Customer-Service/Meter-
Reading-Info-Schedule/Advanced-Metering-Infrastructure-and-Smart-Grid
(SFPUC, 2018)San Francisco Public Utilities Commission, San Francisco Graywater Design Manual for
Outdoor Irrigation. 2018. https://www.urbanfarmerstore.com/wp-
CITY OF PALO ALTOONE WATER PLAN A-3
APPENDIX A
OCTOBER 2024 / FINAL / CAROLLO
content/uploads/2021/05/6_Graywater-L2L_RGW3-Graywater-Design-Manual-
SFPUC.pdf. September 2018.
(SFPUC, 2021)San Francisco Public Utilities Commission, 2020 Urban Water Management Plan for the
City and County of San Francisco. April 2021.
https://www.sfpuc.org/sites/default/files/documents/UWMP%20Public%20Review%20
Draft%2004012021%20FINAL.pdf.
(SFPUC, 2023a)
(SFPUC, 2023b)
San Francisco Public Utilities Commission. Fiscal Year 2023-2024 Wholesale Water
Rates. May 9, 2023.
https://sfpuc.sharefile.com/share/view/se733246b7afe457080762bfc20b8fe2b.
San Francisco Public Utilities Commission,. SFPUC 10-Year Financial Plan FY 2023-2024
to FY 2032-2033. February 2023.
https://sfpuc.org/sites/default/files/about-us/policies-reports/FY24-10-Year-Financial-
Plan-Report.pdf
(SFPUC, 2024)
(SWRCB, 2018)
San Francisco Public Utilities Commission, Alternative Water Supply Plan. February 2024.
https://sfpuc.org/sites/default/files/about-us/policies-
reports/AWS%20Report%20Feb2024_web.pdf.
State Water Resources Control Board, Water Quality Control Plan for the San Francisco
Bay/Sacramento-San Joaquin Delta Estuary. Dec 12, 2018.
https://www.waterboards.ca.gov/plans_policies/docs/2018wqcp.pdf
(SVI, 2020)Silicon Valley Institute for Regional Studies. Palo Alto Business & Economic Activity, May
2020. https://jointventure.org/images/stories/pdf/palo-alto-report-2020-05.pdf
(Todd Groundwater, 2018)Todd Groundwater in association with Woodard and Curran, 2018. Northwest County
Strategic Plan, Groundwater Assessment and Indirect Potable Reuse Feasibility Evaluation
and Implementation Strategy. Prepared for the City of Palo Alto and Santa Clara Valley
Water District. November 2018.
https://cityofpaloalto.org/civicax/filebank/blobdload.aspx?t=64573.3&BlobID=68051
(Valley Water, 2019)
(Valley Water, 2021)
Valley Water in partnership with the cities Palo Alto and Mountain View, Agreement to
Advance Resilient Water Reuse Programs in Santa Clara County. December 10, 2019.
Santa Clara Valley Water District 2021 Groundwater Management Plan for the Santa
Clara and Llagas Subbasins, November 2021. https://s3.us-west-
1.amazonaws.com/valleywater.org.us-west-1/s3fs-public/2021_GWMP.pdf
(Valley Water, 2022)Valley Water, Protection and Augmentation of Water Supplies for FY 2022-2023.
February 25, 2022.
https://www.valleywater.org/sites/default/files/2022-02/2022-02-
18_2022%20PAWS%20Report_for%20online%20version-compressed.pdf.
(Valley Water, 2023a)
(Valley Water, 2023b)
Valley Water (VW, Desalination as a Potential Water Supply in Santa Clara County
Presentation, March 2023.
Valley Water, 2024-2028 Five-Year Capital Improvement Program, July 2023.
https://s3.us-west-1.amazonaws.com/valleywater.org.us-west-1/s3fs-public/2023-
07/CIP_Tab-02_071923_MN.pdf
CITY OF PALO ALTOONE WATER PLAN A-4
APPENDIX A
OCTOBER 2024 / FINAL / CAROLLO
(Valley Water, 2023c)
(Valley Water, 2023d)
Valley Water, Protection and Augmentation of Water Supplies, 52nd Annual Report,
February 2023. https://online.flipbuilder.com/tkap/jyxl/
Valley Water, Website with FAQs regarding Purified Water – Information regarding
energy usage and brine disposal. Information obtained in June 2023.
.https://beheard.valleywater.org/purifiedwaterproject/widgets/34076/faqs#question610
6
(Valley Water, 2023e)
(Valley Water, 2024)
Valley Water, Website with information regarding Valley Water’s Graywater Rebate.
Information obtained in June 2023.
https://www.valleywater.org/saving-water/rebates-surveys/graywater-rebate
Valley Water News, Website information regarding Residential Graywater Systems.
Information obtained in May, 2024.
https://valleywaternews.org/2019/03/21/graywater-direct-install-program-helps-
disadvantaged-communities-reuse-water/
(WaterReuse, 2012)
(W&C, 2019)
WaterReuse Association, Seawater Desalination Costs, January 2012.
Woodard & Curran, Recycled Water Strategic Plan Report, Northwest County Recycled
Water Strategic Plan. Final Report. Prepared for the City of Palo Alto and Valley Water.
July 2019. https://www.cityofpaloalto.org/files/assets/public/v/1/public-works/water-
quality-control-plant/recycled-water/2021/rw-strategic-plan-rpt_vol1_body.pdf
(W&C, 2023),
(W&C, 2017)
Woodard & Curran, Preliminary Finance Plan for the Advanced Water Purification
System Phase 1. Prepared for the City of Palo Alto. April 2023.
Woodard & Curran, 2017, Northwest County Recycled Water Strategic Plan Presentation.
https://watereuse.org/wp-content/uploads/2017/04/RMC-Woodard-and-Curran-_Bay-
Area-WateReuse-Prese-Palo-Alto-Recycled-Water-Strategic-Plan.pdf
CITY OF PALO ALTOONE WATER PLAN A-5
OCTOBER 2024 / FINAL / CAROLLO
APPENDIX B SUPPLY OPTIONS PRE-SCREENING
CITY OF PALO ALTOONE WATER PLAN APPENDIX B
APPENDIX B
OCTOBER 2024 / FINAL / CAROLLO
APPENDIX B OPTIONS PRE-SCREENING
1.1 Introduction
A total of 27 options were initially identified for consideration as a part of the One Water Plan. These
options were subjected to a pre-screening process that removed options if they were either 1) already
ongoing or planned or 2) if they were deemed not feasible at this time. Table B-1 provides the initial
prescreening results. The following sections provide a description of the eight (8) options that were
removed because of the prescreening process as well as the justification for removal.
The 15 options remaining (shown as “pass” in Table B-1) after this pre-screening process were subjected
to the screening process described in Chapter 3.
Table B-1 Summary of Option Prescreening
Pre-ScreeningCategory
Conservation
Option Results
Ongoing
Pass
Planned/Ongoing Conservation Efforts
Enhanced Conservation – Phase 1
Enhanced Conservation – Phase 2 Pass
Advanced Metering Program Ongoing
Ongoing
Pass
Distribution System Water Loss Reduction
GroundwaterGroundwater
Water Reuse
New Irrigation Wells Pass
Non-Potable Reuse (NPR), Phase 3 Extension to Foothills
Direct Potable Reuse (DPR) with Palo Alto Treatment Facility
DPR with Regional Treatment Facility
DPR with Palo Alto Treatment and Small Salt Removal Facility
Indirect Potable Reuse (IPR) with Groundwater Injection
IPR with Lagunita Groundwater Recharge
Graywater Capture and Reuse
Pass
Pass
Pass
Pass
Pass
Removed
Pass
Blackwater Capture and Reuse Removed
PassStormwater Capture Residential Rainwater Capture
and Use Green Stormwater Infrastructure
RWS Imported Water
Pass
Imported Water Pass
Valley Water Treated Water Removed
CITY OF PALO ALTOONE WATER PLAN B-1
APPENDIX B
OCTOBER 2024 / FINAL / CAROLLO
Pre-Screening
ResultsCategoryOption
Interagency Transfer Agreement Removed
Removed
Removed
Removed
Pass
Tuolumne River Purchases
Atmospheric Water Generators
Local Storage
Other
Multi-Source Storage
Bay Water Desalination, Distributed or Centralized
Temporary Dewatering Sites
Permanent Dewatering Sites
Pass
Removed
Removed(1)
Notes:
(1) Eliminated as a standalone alternative, will be considered as a component of reuse projects.
1.2 Planned/Ongoing Conservation Efforts
Description
The City has been engaged in a series of conservation and efficiency efforts, including the preparation of
the 2020 Urban Water Management Plan and Water Shortage Contingency Plan (Palo Alto, 2021). Water
conservation efforts are coordinated and implemented in partnership with agencies such as Valley Water
and BAWSCA to offer programs to Palo Alto customers including the following:
Valley Water Program Partnerships
Water Wise Survey Program: Offered in partnership with Valley Water, this survey informs and
educates consumers on how to use less water for landscaping and within the home.
o The DIY indoor Water Wise Survey portion includes a survey kit and guides to enable
customers to check their homes for leaks and other efficiency improvements.
The outdoor Water Wise Survey includes a comprehensive, professional irrigation
consultation.
o
Landscape Rebate Program: Provides rebates to convert high-water use landscapes to low-
water landscapes, stormwater rebates, and irrigation upgrades.
WaterSmart Home Water Use Report Program: The City delivers monthly home water use
reports through WaterSmart to residential properties enabling them to compare their water use
to other similar households and receive personalized tips. Customers can also log into the
WaterSmart portal to learn more about their usage patterns.
Submeter Rebate Program: Aides in converting mobile home and apartment complexes from a
master water meter to individual submeters.
Waterfluence Irrigation Budget Program: Waterfluence provides a suggested monthly
irrigation budget for commercial sites with dedicated irrigation meters. The budgets are based on
site specific characteristics such as landscape type and local weather data.
CITY OF PALO ALTOONE WATER PLAN B-2
APPENDIX B
OCTOBER 2024 / FINAL / CAROLLO
Large Landscape Survey: Professional landscape irrigation surveys for commercial, industrial,
institutional, and multi-family complex customers with over one-half acre of landscape area. The
survey provides recommendations for improving system efficiency.
BAWSCA Program Partnerships
BAWSCA maintains a Regional Water Conservation program which the City of Palo Alto participates in.
Examples of program elements include educational public workshops to promote smart water practices,
and general technical assistance to member agencies.
Justification for Removal
The existing conservation programs have been removed from consideration due to these already being
implemented. Instead, two phases of further conservation efforts have been identified and will be
considered in the OWP.
1.3 Advanced Metering Program
Description
Advanced metering infrastructure (AMI) entails the installation of “smart” technology to utilize radio and
cell signal telecommunications to detect and transmit utility meter data. The City of Palo Alto is currently
in the process of installing AMI to the approximately 20,000 water service connections within its service
territory. AMI infrastructure is anticipated to be fully implemented for City electric, water, and gas meters
by 2025. AMI infrastructure will allow consumers to monitor their hourly near-real-time consumption data
via the WaterSmart portal. The City will also send out automated continuous use alerts to customers to
notify them of potential leaks.
Justification for Removal
This alternative was removed from consideration because the program is already in the process of being
implemented. With full implementation for AMI infrastructure already planned, there is no additional
expansion opportunities for this project within the OWP.
1.4 Distribution System Water Loss Reduction Program
Description
Non-revenue water is the difference between the amount of water purchased (from SFPUC in this case)
and the amount sold to consumers. This difference is usually due to water metering inaccuracies in the
water system, system flushing, firefighting water, and pipe leakage. In 2023, Palo Alto completed a review
of non-revenue water and determined meter inaccuracies accounted for the majority of non-revenue
water and that pipe leakage was relatively low.
Justification for Removal
This alternative was removed from consideration because this program is already underway and will be
maintained by the City in coming years. There are no additional expansion opportunities for this project
within the OWP.
CITY OF PALO ALTOONE WATER PLAN B-3
APPENDIX B
OCTOBER 2024 / FINAL / CAROLLO
1.5 IPR, Lagunita Groundwater Recharge
Description
The alternative would include construction of an IPR facility and associated infrastructure to transport
purified water to Lagunita, located on Stanford University campus. Water in Lagunita percolates into the
underlying groundwater basin and the new water supply would be used for additional recharge. In turn,
the City could withdraw more water supply from the groundwater basin.
Justification for Removal
Successful implementation of this project requires participation from both the City and Stanford
University. Using a new water source in Lagunita would also require consultation and approval from
United States Fish and Wildlife Service (USFWS) and California Department of Fish and Wildlife (CDFW).
Lagunita was originally a naturally occurring vernal pool, now modified and managed as an ephemeral
wetland, that already provides groundwater recharge from local runoff and supplemental local water
sources. At this time, Stanford has concerns about pursuing the use of Lagunita as a recharge basin using
other water sources, primarily due to environmental and legal concerns. Lagunita currently supports
California tiger salamanders, a federal and state-protected species. Lagunita is a focal point of Stanford’s
Habitat Conservation Plan, with state consistency determination; a series of permits to Stanford from the
USFWS and CDFW. Lagunita also supports more than 400 additional native species of amphibians,
reptiles, mammals, birds, fungi, invertebrates, and plants. Discussions with Stanford regarding the
feasibility of using reclaimed water to partially fill Lagunita have occurred in the past, for the purposes of
this One Water Plan, other water reuse options were pursued instead.
1.6 Blackwater Capture and Use
Description
This alternative includes the on-site reuse of blackwater either on a customer-scale or at City facilities.
Blackwater is wastewater from toilets. An onsite blackwater system commonly treats the water to non-
potable reuse standards for use in on-site irrigation. This alternative would include City-provided rebates
for customer-installed blackwater systems as well as system installations at City facilities such as fire
stations, community centers, and libraries.
Justification for Removal
This alternative was removed from consideration due to operational and regulatory complexities as well as
potential depletion of wastewater flows to the Regional Water Quality Control Plant which would reduce
the treated effluent available for possible water reuse options. A blackwater system is effectively a small-
scale wastewater treatment plant, requiring multiple treatment processes and continuous monitoring.
Ineffective operation and maintenance of these systems could lead to public health concerns. There would
likely need to be dedicated staff to maintain the City-installed systems and a comprehensive level of
public outreach and education to implement customer-scale systems. By focusing on larger-scale water
reuse, the City would achieve a higher volume of water reuse per FTE of city staff.
CITY OF PALO ALTOONE WATER PLAN B-4
APPENDIX B
OCTOBER 2024 / FINAL / CAROLLO
Should blackwater be considered in the future, it ideally would be implemented in conjunction with
adjacent cities/utilities. Having a regional, coordinated, effort would reduce burden on local staffing and
provide more coordinated local ordinances to facilitate the use of non-traditional water sources, such as
blackwater.
1.7 Valley Water Treated Water
Description
This alternative would extend the existing Valley Water treated water distribution system by constructing
the West Pipeline to connect to the RWS and serve Palo Alto at the Page Mill turnout. Palo Alto would
purchase potable water from Valley Water and receive it via the West Pipeline connection.
Valley Water manages the Santa Clara County groundwater and produces and delivers treated drinking
water to retail agencies throughout the county. In addition to groundwater, their water portfolio includes
State Water Project (SWP) and Central Valley Water Project water as well as local reservoirs. Valley Water
anticipates reliable water supply through 2040 (Palo Alto, 2017).
Justification for Removal
Ultimately, development and implementation of this project is not within the City’s control at this time
and would require a regional effort with many collaborating agencies to initiate. In addition, Valley
Water’s existing supply portfolio will also be challenged with similar climate change-exacerbated issues
and prioritizing serving their existing customers. The 2017 WIRP analysis found that Valley Water is
unlikely to have water available to sell to Palo Alto in dry years and the cost of constructing the West
Pipeline, should it be borne solely by Palo Alto, would be significantly more expensive than other water
options.
1.8 Interagency Transfer Agreement
Description
A specific project is not defined, but this would include purchasing additional water from another water
agency and constructing the necessary infrastructure, similar to the Valley Water Treated Water supply
alternative.
Justification for Removal
This alternative was removed from consideration because it is not within the City’s control to initiate a
transfer agreement. Additionally, other local suppliers are likely to be facing similar future supply issues as
Palo Alto (via RWS) will face.
1.9 Tuolumne River Purchases
Description
An option proposed during the stakeholder process is Tuolumne River water rights purchases. This entails
approaching farmers or others to purchase water released for fish in Tuolumne River.
CITY OF PALO ALTOONE WATER PLAN B-5
APPENDIX B
OCTOBER 2024 / FINAL / CAROLLO
Justification for Removal
Further investigation revealed that this alternative would not provide new supply to the City. Rather,
purchasing these water rights is an environmental action to protect fish habitat in the Tuolumne River.
1.10 Atmospheric Water Generators
Description
This alternative includes the on-site use of Atmospheric Water Generators (AWGs) either on a customer-
scale or at City facilities. This alternative would include City-provided rebates for customer-installed AWGs
as well as system installations at City facilities such as fire stations, community centers, and libraries.
AWGs range from home-based units that can produce 1 to 20 liters of water per day to commercial-scale
units capable of 1,000 to over 10,000 liters per day. Water production rates are highly dependent upon
the air temperature and the amount of water vapor (i.e., humidity) in the air. The most commonly used
AWG systems employ condenser and cooling coil technology to pull moisture from the air in the same
way a household dehumidifier does. Although significant quantities of energy can be required to operate
these condenser and fan systems, recent technological advancements have substantially improved the
energy-water ratio (EPA, 2021).
Justification for Removal
This alternative was removed from consideration due to high unit cost and low water yield. A 2018 EPA
report performed a life cycle cost assessment of a range of AWGs. Home scale AWGs yield 1 to 20 L/day
and commercial scale AWGs yield 1,000 to 10,000 L/day, which equates to approximately 0.3 to 3 afy (EPA,
2018). The subsequent unit cost is around $100,000/af, significantly higher than other options being
considered.
1.11 Local Storage
Description
A specific project is not defined, but this would include building surface storage within the City's
boundaries and/or a local watershed. This could be larger-scale underground or above ground storage for
stormwater or recycled water.
Justification for Removal
There were no additional local storage ideas identified aside from the multi-source storage and Lagunita
storage (via IPR) which were addressed as separate alternatives. Therefore, it was decided that storage
options were adequately addressed in other alternatives that moved forward in the screening process.
CITY OF PALO ALTOONE WATER PLAN B-6
APPENDIX B
OCTOBER 2024 / FINAL / CAROLLO
1.12 Temporary Dewatering Sites
Description
Shallow groundwater in the City leads to frequent instances of dewatering necessitated when a basement
is constructed. In some instances, the City utilizes the water for localized reuse and fill stations during a
dewatering project (WIRP).
Dewatering is permitted from April through Oct (to avoid overflowing the storm drain system) and
allowed for a 12-week duration plus a 2-week startup per site. Exceptions are granted under special
circumstances and must be permitted by the City. 461 AF of water was produced from 15 sites that were
dewatered from July 2019 to Aug 2020. Only 6 AF of this water was reused. (W&C, 2020a). This temporary
dewatering alternative would propose utilizing all, or a larger portion of, the water from existing
temporary dewatering sites for City park irrigation.
Justification for Removal
The alternative was removed from consideration due to lack of local control, high cost, and environmental
concerns. This alternative does not provide the City a with locally controlled source of supply. Typically,
these are residential construction projects on private property so the yield would be inconsistent and up
to the discretion of the property owner to a degree.
In addition, because these sites are all over the City, trucking would be required to move the water to
areas for use. It is estimated to cost approximately $73,000 to haul 2.8 AF of water, resulting in a unit cost
of approximately $26,000/AF for truck trips only, significantly higher than other options being considered.
(W&C, 2020a)
Although this option will not be carried forward for consideration in this Plan, it is recommended the City
continue encouraging local reuse for these projects as there is considerable local support.
1.13 Permanent Dewatering Sites
Description
Due to the shallow groundwater table, there are two permanent dewatering sites within the City, located
at the Oregon Expressway and at Palo Alto City Hall.
The Oregon Expressway is located at the Oregon Expressway underpass (at the intersection of the Oregon
Expressway and Alma Street) and owned and operated by Santa Clara County. Annual discharge has
ranged from 103 to 179 MG/year since 2016. Average daily flow between 0.3 to 0.5 MGD over the same
time period. Discharge is highest from February to July and lowest in December and January. Flows are
conveyed to the stormwater system and ultimately discharged to the Bay. (W&C, 2020a)
The City Hall site (located at Palo Alto City Hall) is owned and operated by the City. There are no flow
records, but it is assumed that flows are approximately the same as Oregon Expressway site.
This alternative would redirect the discharge from both of these sites to the sewer system flowing to Palo
Alto’s Regional Water Quality Control Plant (RWQCP). This additional water source would increase flows
for a future potable reuse project.
CITY OF PALO ALTOONE WATER PLAN B-7
APPENDIX B
OCTOBER 2024 / FINAL / CAROLLO
Justification for Removal
This alternative is being removed from consideration as a singular option but will remain in the water
supply portfolios considered as a component of the water reuse project(s) carried forward. Because this
supply will ultimately be used to augment water reuse projects, it will be considered as additional flow to
these selected projects.
CITY OF PALO ALTOONE WATER PLAN B-8
OCTOBER 2024 / FINAL / CAROLLO
APPENDIX C COST ESTIMATING DETAILS
CITY OF PALO ALTOONE WATER PLAN APPENDIX C
Summary 2023 Costs
Imported
SFPUC*
Conservation Groundwater Water Reuse Desalination
Enhanced Enhanced
Conservation,
Phase 2
Emergency Well
Conversion Full
Treatment
DPR, Palo Alto
Facility with
SSRF
IPR,
Groundwater
Injection
DPR, Palo Alto
Facility
Non Potable
Reuse
Bay Water
DesalinationConservation,
Phase 1
DPR, Regional Facility
OWP Capital Cost ($)
Treatment
Conveyance
Pump Stations
Storage Tank
Injection Well
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0 $0 $23,132,965
$26,143,000
$64,723
$26,517,236
$10,345,323
$3,460,571
$8,194,056
$0
$0 $5,324,997
$5,555,533
$1,944,837
$4,605,050
$0
$52,754,827
$57,646,675
$2,638,532
$624,723
$1,480,400
$60,027,579
$6,849,565
$0
$251,832,599
$0$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$7,286,400
$0
$0
$0
$420,073
$0
$0
$0 $6,446,109
$68,824,318
$188,900,000
$7,400,000
$196,300,000
$0 $0
Mark-ups & General Requirements
Capital Cost Excluding Land Acquisition
Land Acquisition Cost
Included
$49,760,760
$0
$56,733,887
$105,251,073
$11,463,000
$116,720,000
$9,117,126
$16,410,000
$0
$31,466,953
$48,897,370
$7,400,000
$56,300,000
$80,169,543
$148,510,000
$0
Included
$251,832,599
$43,560,000
$295,400,000$49,770,000 $16,410,000 $148,510,000Total Capital Cost (rounded)
Operations & Maintenance (O&M) Cost ($)
Treatment $0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$1,811,749 $8,975,193
$7,397
$223,122
$90,863
$81,913
$0
$0 $2,007,583
$1,783
$53,774
$45,045
$19,742
$0
$6,012,364
$30,065
$141,558
$988,458
$0
$358,400
$74,903
$447,087
$117,044
$0
$9,827,073
Conveyance $0 $4,780 $0
Pump Stations, Except Energy Costs
Energy Costs
$0 $0 $0
$99,964 Included in Cost of Water $1,281,486
Storage Tank $0 $0 $0
$0
$0
$0
$0
Injection Wells $0
$5,172,000
$0
$0
$0
$96,692
$5,671,960
$0
$0
Groundwater Pumping Charge
Wellhead Treatment
$0 $0 $0
$0 $0 $0 $0
Cost of Water $24,267,125 $0 $0 $6,044,840 $0 $0 $0
Average Lifetime Staffing and Program
Costs $0 $188,176
$190,000
$639,142
$640,000
$0 $0 $0 $0 $0 $0 $0
$24,270,000 $7,090,000 $9,380,000 $6,050,000 $2,130,000 $12,950,000 $1,000,000 $11,110,000Total OWP O&M Cost (rounded)
1
Summary (AF)
Imported
SFPUC
Conservation Groundwater Water Reuse Desalination Units
Enhanced Enhanced
Conservation,
Phase 2
Emergency Well
Conversion Full
Treatment
DPR, Palo Alto
Facility with
SSRF
IPR,
Groundwater
Injection
DPR, Palo Alto DPR, Regional
Facility Facility
Non Potable
Reuse
Bay Water
DesalinationConservation,
Phase 1
Cost Escalation Programmatic Cost Programmatic Cost Cost Escalation Cost Escalation Cost Escalation Cost Escalation Cost Escalation Cost Escalation Cost EscalationCost Method Method Estimate Estimate Method Method Method Method Method Method Method
Total Capital Cost
Capital Cost $0
$0
$0
$0
$0
$0
$0
$0
$0
$49,760,760
$0
$105,257,000
$11,463,000
$7,592,804
$16,410,000
$0
$48,900,000
$7,400,000
$3,662,396
$188,900,000
$7,400,000
$148,510,000
$0
$251,832,599
$43,560,000
$19,215,712
$
$
$
Land Acquisition Cost
Amortized Capital and Land Cost
Total Annual O&M Cost
Groundwater Production Charge
O&M Cost
$3,408,068 $1,067,494 $12,769,597 $9,660,789
$0
$24,267,125
$0
$0
$188,176
$0
$0
$639,142
$0
$5,172,000
$1,811,749
$99,964
$0 $0 $0 $5,671,960
$6,213,260
$1,054,780
$0 $0 $ per Year
$ per Year
$ per Year
$9,305,267
$74,733
$6,049,640
$270,999
$1,897,644
$45,045
$909,679
$82,592
$9,827,073
$1,281,486Energy Cost
Total Unit Cost
Total Annual Cost $24,267,125 $188,176 $639,142 $10,491,781 $16,972,804 $7,117,134 $5,605,085 $25,709,597 $10,570,467 $30,324,272 $ per Yr
Acre Feet per
YearProject Yield 10,982
$0
582
$0
330
$0
2,250
$1,515
$2,299
$805
4,723
$1,608
$0
1,769
$603
$0
630
$5,813
$0
5,150
$2,480
$1,101
$1,206
$205
1,100
$8,783
$0
4,480
$4,289
$0
Capital Cost Unit Cost
GPC Unit Cost
$ per AF
$ per AF
$ per AF
$ per AF
$ per AF
$0 $0 $0
O&M Unit Cost $2,210
$0
$323
$0
$1,939
$0
$1,970
$16
$3,420
$153
$4,024
$3,012
$71
$827
$75
$2,193
$286Energy Unit Cost
Total Unit Cost
$44
$2,210 $323 $1,939 $4,663 $3,594 $8,897 $4,992 $9,610 $6,768
Note: Energy cost estimate for DPR, Regional Facility is a separate estimate and is not additive to O&M estimate; energy cost estimate for DPR, Palo Alto Facility and Emergency Well Conversion Full Treatment includes pump station energy costs while
the energy costs of treatment are included with other O&M costs.
Future Cost Basis 2045
Imported Conservation Groundwater Water Reuse Desalination Units
Enhanced
Conservation,
Phase 1
Enhanced
Conservation,
Phase 2
Emergency Well
Conversion Full
Treatment
DPR, Palo Alto
Facility with
SSRF
IPR,
Groundwater
Injection
DPR, Palo Alto DPR, Regional Non Potable
Reuse
Bay Water
DesalinationSFPUCFacilityFacility
Total Capital Cost
Capital Cost $0
$0
$0
$0
$0
$0
$0
$0
$0
$53,304,971
$0
$159,050,554
$17,321,380
$11,473,247
$29,450,626
$0
$73,891,257
$11,181,908
$5,534,131
$240,333,553
$9,414,867
$188,946,193
$0
$380,536,347
$65,822,151
$29,036,261
$
$
$
Land Acquisition Cost
Amortized Capital and Land Cost
Total O&M Cost
$3,650,808 $1,915,805 $16,246,493 $12,291,221
Groundwater Production Charge
O&M Cost
$0
$49,517,551
$0
$0
$418,502
$0
$0
$1,421,444
$0
$19,262,570
$4,029,311
$159,607
$0 $0 $0 $21,124,618
$13,818,221
$1,684,115
$0 $0 $ per Year
$ per Year
$ per Year
$20,694,811
$119,323
$13,454,332
$432,691
$4,220,340
$71,921
$2,023,115
$131,871
$21,855,303
$2,046,084Energy Cost
Total Unit Cost
Total Annual Cost $0 $418,502 $1,421,444 $27,102,295 $32,287,381 $15,370,137 $9,826,392 $52,873,447 $14,446,208 $52,937,648 $ per Yr
Acre Feet per
YearProject Yield 12,113
$0
582
$0
330
$0
2,250
$1,623
$8,561
$1,791
$71
4,723
$2,429
$0
1,769
$1,083
$0
630
$8,784
$0
5,150
$3,155
$4,102
$2,683
$327
1,100
$11,174
$0
4,480
$6,481
$0
Capital Cost Unit Cost
GPC Unit Cost
O&M Unit Cost
Energy Unit Cost
Unit Cost
$ per AF
$ per AF
$ per AF
$ per AF
$ per AF
$0 $0 $0
$4,088
$0
$719
$0
$4,313
$0
$4,382
$25
$7,606
$245
$6,699
$114
$1,839
$120
$4,878
$457
$4,088 $719 $4,313 $12,045 $6,836 $8,689 $15,597 $10,267 $13,133 $11,815
Note: Energy cost estimate for DPR, Regional Facility is a separate estimate and is not additive to O&M estimate; energy cost estimate for DPR, Palo Alto Facility and Emergency Well Conversion Full Treatment includes pump station energy costs while
the energy costs of treatment are included with other O&M costs.
2
Assumptions
Cost Methods Description
Cost Escalation Method Costs are based onaprevious study and are updated to account for escalation or anticipated changes in timefor labor, material, and equipment.
Programmatic Cost Estimate
Bottom Up Calculation
Annual estimation of costs and water use/water savings for projects withoutcomponent.a significant capital/infrastructure
Full conceptual level cost estimate for projects that do not haveaprevious cost study.
Construction Cost Markups (used to calculate Capital Cost Multipliers)(1)
Total Raw Construction Cost Subtotal (1)100%
General Requirements, incl. de/mobilization
Sales Tax
8%of Subtotal (1)
of Subtotal (1)9.375%
17%Construction Cost Subtotal
Construction Cost Contingency
Construction Cost Total
Subtotal (2)
Subtotal (3)
117%
164%
40%
40%
of Subtotal (2)
General Contractor Overhead (OH), Profit, Risk, 3% Bond Insurance 10%of Subtotal (3)
of Subtotal (3)
Pre-design pilot testing/outreach (Direct Potable Reuse (DPR)/Desalination(Desal))10%
0%Pre-design pilot testing/outreach (other)
Engineering(2)10%
10%
5%
of Subtotal (3)
of Subtotal (3)
of Subtotal (3)
of Subtotal (3)
of Subtotal (3)
Construction Management
Admin, Environmental
Admin, Environmental
&
&
Legal (DPR/Desal)
Legal (other)3%Engineering Services During Construction
Capital Cost
4%
DPR/Desal Options 49%
37%
Subtotal (4)245%
225%Other Options
(1) Breakdown ofmarkups in this table are used to calculate markups for "Capital CostMultiplier byProjectType" table
(2) Reflects an average of10%for engineering. Could range from6%(pipelines) to 12%(treatmentplants, pump stations)
Capital Cost Multiplier by Option Type (USED FOR OPTION CALCS)
(1) Capital Cost multiplier (DPR/desal) (Subtotal (4))2.45
2.35(2) Capital Cost multiplier (IPR) (1) (3)+/ 2
(3) Capital Cost multiplier (other options/infrastructure) (Subtotal (5))2.25
1.17(4) Capital Cost multiplier (prefabricated components) (Subtotal (2))
Note: Accounting for variance in design/pilottesting/environmental/outreach complexities
Engineering News Record (ENR)multiplier to Current Month/YearCost Basis Assumptions Value
Current ENR Index (SF Area: Sept, 2023)
Current Month/Year
15,490
September 2023
15,367ENR Index (Water Main Replacement (WMR) 29, June 2019)1.01
1.03ENR Index basis (Greater SF Area, September 2022)ENR Index (Northwest County Recycled Water Strategic Plan, TechnicalMemorandum 6.4, December 2020)
15,083
13,169
12,368
12,354
1.18
1.25
1.25
ENR Index (CoRe Plan, August 2019)
ENR Index (WMR 27, June 2019)
ENR Index (Groundwater Assessment/Indirect Potable Reuse (IPR) Study, Nov2018)12,110
12,015
11,155
1.28
1.29
1.58
ENR Index (NW County RWSP, June 2018)
One Water Los Angeles 2040 Plan (Los Angeles, July 2016)
ENR Index (BAWSCA Long Term Regional Water Strategy Phase II, Feb 2015)
ENR Index (WateReuse Study, January 2012)
11,178
10,208
1.39
1.52
ENR Index (Carollo Groundwater Study, May 2000)
RSMeans correction SoCal to Bay Area (2021)
Interest Rate (50 year average)
7,164 2.16
1.14126.9/111.8
5.0%50-year Historical Fed RateUS Bureau of Statistics, CPI SanFranciscoInflation Rate (Bay Area, 2023)3.4%
Long-Term Interest Rate (for future Capital Expense (CAPEX) escalation)5.0%Historic Average or Hard Enter
Note: All ENR index values reflect Greater San Francisco Bay Area; RSMeans is a database of current construction cost estimates
Depreciation Periods
Civil infrastructure (pipelines, buildings)40
30
years
yearsOptions with multiple components (civil, mechanical, structural)
Mechanical infrastructure (Pump Station (PS), treatment plants)
Electrical equipment (SCADA, monitoring)
20
15
10
years
years
yearsMembrane replacements Reverse Osmosis (RO)
Pipeline Cost (pressurized, Water (W) & Recycled Water (RW))
Diameter (in)
4
Project Bid Time ENR (SFBAY)Unit Cost Bid Data Unit Cost (June '23 $)Bid Data Cost/inch Diameter Unit Cost ($/lineal ft)1
$520
Extrapolated Cost/inch diameter
$130
Water Main Replacement (WMR) 29 Jun-23
Jun-23
Jun-23
Jun-23
Jun-19
Jun-19
15,367
15,367
15,367
15,367
12,354
12,354
$630
$530
$680
$730
$627
$688
$630
$530
$680
$730
$780
$856
$105
$66
$68
$61
$45
$43
$560 $936
8 WMR 29
WMR 29
WMR 29
WMR 27
WMR 27
$620
$690
$78
$69
$62
$56
$53
$51
$48
$42
$35
10
12
14
16
18
20
24
$740
$790
$850
$910
$960
$1,010
$1,06030
Special Construction Extra Markups
Pipelines w/jack&bore
Tunneling
200%
300%
50%Offshore pipelines
Source: Palo Alto project bids for WMR 29 (June, 2023) and WMR 27 (June, 2019) and extrapolation of trendline
1) Where bid data differed from trendline, value from trendline was used. See graph to the right for trendline values
Pump Stations (W & RW)
Capacity (Horsepower (HP))Unit Cost ($/HP)
1-5 $10,000
$9,000
$8,000
$7,500
$6,700
$5,400
$4,000
5-10
10-50
51-100
101-250
250-500
500 and larger
Source 100-500 HP: South Pasadena One Water Plan, Carollo (November 2021) with RS Means index (LA to SF) and ENR correction to 15,490.
Source: <100 HP extrapolated from curve 100-750 HP (South Pasadena One Water Plan (November 2021)) after RS Means and ENR index corrections
Groundwater Wells
New Well Motor only $100,000
$150,000
$250,000
$500,000
$500,000
$1,000,000
New Well Pump only
Well Rehab
Drilling
Equipping
New Well (total)
Source: South Pasadena One Water Plan, Carollo (November 2021) with RS Means index (LA to SF) and ENR correction to 15,490.
Irrigation Demand Assumptions
Irrigation Duration (hrs/day)4
6Peak Hour Demand Peaking Factor
Minimum Net Positive Suction Head(NPSH) (psi)5
Minimum Irrigation pressure (psi)60
Concrete Storage Reservoirs (W & RW)
Volume (million gallons (MG))Cost per gallon
<1 $7.00
$5.50
$4.50
1
3
5
to
to
3
5
to 10 $3.75
Special Construction Extra Markups
Below-ground construction markup
Small prefabricated tanks
100%
$1.00
Assumed to be 2x more expensive
Source: South Pasadena One Water Plan, Carollo (November 2021) with RS Means index (LA to SF) and ENR correction to 15,490.
Labor Cost
Category Annual Salary $/hr (raw salary)$/hr (labor cost)
Labor Cost
Labor Cost
Labor Cost
-
-
-
low range
mid range
high range
$50,000
$100,000
$150,000
3.5
$24
$48
$72
$84
$168
$252
City labor cost multiplier
WC Staff Salary Benefits
Salary Benefits
-&$167,000
$167,000
n/a
n/a
$80
$80Operations Staff-&
Land Cost
Land Value in Palo Alto $/sq ft Source
Land Value Rinconada $482 City Staff
3
Assumptions
Land Value Fernando $330
$372
$50
City Staff
Land Value Peers City Staff
Low Industrial Land City Staff
High Industrial Land $150
$200
$500
City Staff
Value Used for Supply Options
Land Value Used in RWSP
City Staff
(Todd Groundwater 2018)
4
Assumptions
O&M Cost Estimates
Pipelines Repair and Replacement 0.5%
1%
of annual CAPEX
of annual CAPEX
of annual CAPEX
Storage Tanks Repair and Replacement
Pump Stations Repair and Replacement 2%
Stormwater BMP Repair and ReplacementConventional Water Treatment Repair andReplacement
3%
4%
of annual CAPEX
of annual CAPEXAdvanced Water Treatment Repair andReplacement 6%of annual CAPEX
Ocean Desal Treatment Repair andReplacement 25%of annual CAPEX
per kWhEnergy Cost 2023 $0.10
COST ESCALATION METHOD
Historical Cost Escalation (ENR index)
Historical Cost Escalation (Handy-Whitman)
Cost Escalation from previous reports to current year
Selected Method
Rate
3.50%
5.70%
Notes/Sources
Average ENR increase for San Francisco Bay Area from 2003 to 2023
Average Handy-Whitman (water sector specific) increase for San Francico Bay Area from 2003 to 2023
Historical Cost Escalation (ENR index)
Selected Multiplier for current year estimates
Future Cost Escalation for Capital Cost
Future Cost Escalation for O&M Cost
Construction Materials
3.5%
3.50%
3.70%
2.15%
2.92%
Using RS Means City Cost Index for San Jose, 2007 to 2023
Electricity Uses the average increase in electricity cost for the City of Palo alto over the next 20 years
Average
Future Cost Escalation for Labor Cost
Construction Labor/Installation Cost 5.30%Using RS Means City Cost Index for San Jose, 2007 to 2023.
In-house Government Labor in water sector
Average
3.10%
4.20%
Using Federal Reserve Economic Data for State and Local Government Workers service occupations, 2005 to 2023.
COST ESCALATION ASSUMPTIONS
22 variable 3.5%3.7%4.2%3.4%9.5%2.1%
GW production charge(2)w/inflation 2033-2024 GW production charge(2)w/9.5% escalation 2033-2024Planning Year
Net Present Value
2023
SFPUC Rates (1) ($/AF)Capital Cost O&M Cost Labor Cost Energy Cost % Increase Energy Cost
$1,693 $2,345 $3,033 $0.08
$2,069
$2,269
$2,269
$2,269
$2,313
$2,452
$2,541
$2,612
$2,617
$2,630
$2,688
$2,800
$2,898
$2,999
$3,104
$3,213
$3,326
$3,442
$3,562
$3,687
$3,816
$3,950
$4,088
100%
104%
107%
111%
115%
119%
123%
127%
132%
136%
141%
146%
151%
156%
162%
168%
173%
179%
186%
192%
199%
206%
213%
100%
104%
108%
112%
116%
120%
124%
129%
134%
139%
144%
149%
155%
160%
166%
172%
179%
185%
192%
199%
207%
214%
222%
100%
104%
109%
113%
118%
123%
128%
133%
139%
145%
151%
157%
164%
171%
178%
185%
193%
201%
210%
219%
228%
237%
247%
$1,724
$1,983
$2,280
$2,506
$2,754
$3,027
$3,327
$3,656
$3,894
$4,147
$4,289
$4,436
$4,587
$4,744
$4,906
$5,074
$5,248
$5,427
$5,613
$5,805
$6,003
$6,209
$6,421
$1,724
$1,983
$2,280
$2,506
$2,754
$3,027
$3,327
$3,656
$3,894
$4,147
$4,541
$4,972
$5,445
$5,962
$6,528
$7,149
$7,828
$8,571
$9,386
$10,277
$11,254
$12,323
$13,493
$0.10
$0.11
$0.11$0.11
$0.11
$0.12
$0.12
$0.12
$0.12
$0.13
$0.13
$0.13
$0.13$0.14
$0.14
$0.14
$0.15
$0.15
$0.15
$0.16
$0.16
$0.16
$0.17
2024 103%
106%
108%
109%
111%
113%
115%
117%
119%
120%
122%
124%
127%
129%
131%
134%136%
138%
140%143%
145%
147%
2025
2026
2027
2028
2029
2030
2031
2032
2033
2034
2035
2036
2037
2038
2039
2040
2041
2042
2043
2044
2045
(1) From SFPUC published rates in (SFPUC 2023a), (SFPUC 2023b), and
2034 through 2045 projected from historical rate increase since 2013 (See SFPUC Tab)
(2): From (Valley Water, 2022) (Figure 4-2.1) projected Groundwater Production Charge through year 2023. Escalated with inflation from 2033-2045.
Selection
GW Production Charge
Inflation 2033-2024
9.5% escalation 2033-2024
Treatment and Pumping Efficiencies
DPR (W&C, 2019)75%
84%
70%
DPR (B&C, 2021)
Pump Station pump& motor efficiency
Secondary UV Capital Cost Sources and Escalation Secondary UVModelApproximate Flow (mgd)
0.3
Direct Cost
$70,800
Source Notes $100,000
$50,000
$0
Spektron 250
Spektron 350
(Carollo 2023a)
The Spektron 350 is appropriate for flow ranges from 0.4 to0.7 mgd, this cost was selected for the DPRoption.
y=0.542000x+0.6582000.7 $87,600 +SSRF supply 0 0.1 0.2 0.3 0.4 0.7 0.8(Carollo 2023a)Flow (MGD)Interpolation for Palo Alto DPR 1.00 $100,200 Developing anticipated unit cost based on vendor quotes
Calcite Contactor Capital Cost Sources and Escalation Calcite Contactors
Model Approximate Flow (mgd)Direct Cost Source Notes $540,000$520,000$500,000$480,000$460,000
Wigen, Two 6' Dia Vessels with 7' sidewalls
Wigen, Two 8' Dia Vessels with 7' sidewalls
0.1
0.2
$470,000
$520,000
(Carollo 2023a)
(Carollo 2023a)
y=500000x
0.1
+420000
0.1500.05 0.2 0.25
Developing anticipated unit cost based on vendor quotes.
Assuming approximately 30% of flow through contactor.Flow (MGD)Interpolation for Palo Alto DPR 1.00 $920,000
Conservation Rebates
Device/Program Rate ($)Unit
/ toilet
/ survey
Cost per toilet replacement
City Spatial Analysis Survey
$875
$15,000
$2
$
$
Turf Replacement
Turf Replacement
-
-
Rebate Rate $
$
/ square foot
/ square footInstallation Costs $2
Conservation Measure Savings Rates
Device/ProgramSavings per High Efficiency ToiletReplacement
Rate ($)Unit Source
ccf/year 12.19
36
City Staff
City StaffTurf Replacement Savings Rate gallons/square foot
Treatment Costs
Sewer Connection Fee
Sewer Capacity Fee
Details
One Time Rate, 6-inch connection,depth at feet and below
Cost ($/unit)Unit
Per Connection
$/100 ft^3
6 $9,846
$9.08Quantity Rate, per 100 cubic feet
Unit Conversions
From To
mgd
mg/year
AF
Conversion (divide by)
afy 1,120
afy 3.57
325,851
1.61
gallon
gpm
mgd
mg
afy
gpm
ccf
694.44
1,336.80
436ccfaf
acre
mile
sq ft
ft
43,560
5,280
Treatment Costs
Type of Treatment
Groundwater Nitrate Treatment
Satellite Surface WTP
Original Unit Cost ($/gallon)Cost Basis Year Current Unit Cost ($/gallon)Source$1.00
$3.00
$15.00
$3.00
$5.00
$7.00
$8.00
$4.00
$12.00
$2018 dollars (SoCal)
$2018 dollars (SoCal)
$2018 dollars (SoCal)
$2018 dollars (SoCal)
$2018 dollars (SoCal)
$2018 dollars (SoCal)
$2018 dollars (SoCal)
$2018 dollars (SoCal)
$2018 dollars (SoCal)
$1.50
$4.50
(Carollo, 2018b)
(Carollo, 2018b)
(Carollo, 2018b)
(Carollo, 2018b)
(Carollo, 2018b)
(Carollo, 2018b)
(Carollo, 2018b)
(Carollo, 2018b)
(Carollo, 2018b)
Satellite (Wastewater) WRP
Satellite Stormwater Treatment Plant
Membrane Bioreactor Treatment
Advanced WTF for IPR
$22.00$4.50
$7.50
$10.25$11.75
$6.00
Advanced WTF for DPR
Brackish Groundwater treatment
Ocean Desalination $17.75
5
SFPUC
SFPUC
Cost Estimate Summary Table
Project Cost Units
Total Capital Cost
Capital Cost $0
$0
$0
$
$Land Acquisition Cost
Amortized Capital and Land Cost
Total O&M Cost
$ per Year
Groundwater Production Charge (GPC)$ per Year$0
$24,267,125
$0
O&M Cost $ per Year
$ per YearEnergy Cost
Total Unit Cost
Total Annual Cost
Project Yield
$24,267,125
10,982.4
$ per Yr
AFY
Capital Cost Unit Cost
GPC Unit Cost
O&M Unit Cost
Energy Unit Cost
Unit Cost
0.0
0.0
$ per AF
$ per AF
$ per AF
$ per AF
$ per AF
$2,210
0.0
$2,210
Cost Escalation Method
Unit Cost
Quantity Unit Unit Cost Cost Estimate Source Notes
Unit Cost
SFPUC Base Rate
BAWSCA Debt Service
Cost Summary
Total Cost
10,982
1
af
$
$2,069 $22,723,701
$1,543,424
(SFPUC, 2023a, Slide 7)
Estimate from City Staff
Palo Alto demand multiplied by unit cost
$1,543,424
$24,267,125
10,9822023 Demand (afy)
Unit Cost per AF $2,210
6
SFPUC
Projected Costs and Demand
Year Palo Alto
Demand (4)
BAWSCA
Debt Service (5)SFPUC Base Rate (1, 2, 3)Unit Cost Total Projected Cost
CY $/ccf
2.93
2.45
2.93
3.75
4.10
4.10
4.10
4.10
4.10
4.10
4.75
5.21
5.21
5.21
5.31
5.63
5.83
6.00
6.01
6.04
6.17
6.43
6.65
6.89
7.13
7.38
7.63
7.90
8.18
8.46
8.76
9.07
9.38
Annual Increase
-
$/af afy $$/af
-
$
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
2025
2026
2027
2028
2029
2030
2031
2032
2033
2034
2035
2036
2037
2038
2039
2040
2041
2042
2043
2044
2045
1,276
1,067
1,276
1,633
1,786
1,786
1,786
1,786
1,786
1,786
2,069
2,269
2,269
2,269
2,313
2,452
2,541
2,612
2,617
2,630
2,688
2,800
2,898
2,999
3,104
3,213
3,326
3,442
3,562
3,687
3,816
3,950
4,088
---
-16.4%
19.6%
28.0%
9.3%
0.0%
0.0%
0.0%
0.0%
0.0%
15.9%
9.7%
0.0%
0.0%
1.9%
6.0%
3.6%
2.8%
0.2%
0.5%
2.2%
4.2%
4.2%
4.2%
4.2%
4.2%
4.2%
4.2%
4.2%
4.2%
4.2%
4.2%
4.2%
----
----
----
10,061
11,156
10,562
10,921
10,986
10,811
10,982
11,182
11,287
11,295
11,316
11,350
11,374
11,394
11,421
11,447
11,476
11,508
11,546
11,591
11,641
11,691
11,743
11,801
11,864
11,926
11,988
12,051
12,113
1,889,496
1,782,456
1,991,736
1,806,144
1,737,240
1,726,200
1,543,424
1,681,620
1,602,921
1,602,921
1,602,921
1,602,921
1,602,921
1,602,921
1,602,921
1,602,921
1,602,921
1,602,921
1,602,921
0
1,974
1,946
1,975
1,951
1,944
1,946
2,210
2,420
2,411
2,411
2,455
2,594
2,682
2,753
2,757
2,770
2,828
2,939
3,037
2,999
3,104
3,213
3,326
3,442
3,562
3,687
3,816
3,950
4,088
$19,857,998
21,706,580
20,855,002
21,310,568
21,357,752
21,034,169
24,267,125
27,058,148
27,217,379
27,236,552
27,777,619
29,437,937
30,500,716
31,362,781
31,491,284
31,709,873
32,450,948
33,826,060
35,062,419
34,767,117
36,137,661
37,564,940
39,051,149
40,617,382
42,262,997
43,971,280
45,749,079
47,599,155
49,517,551
0
0
0
0
0
0
0
0
0
1 (SFPUC, 2023a, Slide 7)
2 (SFPUC, 2023a, Table 1)
3 SFPUC Rates from 2032-2045 calculated using average % increase since 2013
4 City Staff.
5 BAWSCA Debt Service from City Staff Estimate. Assumes this remains zero after 2036
7
Enhanced Conservation
Enhanced Conservation
Project
Cost Estimate Summary Table
Phase 1 Phase 2 Units
Total Capital Cost
Capital Cost $0
$0
$0
$0
$0
$0
$
$Land Acquisition Cost
Amortized Capital and Land Cost
Total O&M Cost
$ per Year
O&M Cost $188,176 $639,142 $ per Year
Total Unit Cost
Total Annual Cost $188,176
582
$639,142
330
$ per Year
AFYProject Yield
Capital Cost Unit Cost
O&M Unit Cost
Total Unit Cost
$0 $0 $ per AF
$ per AF
$ per AF
$323
$323
$1,939
$1,939
Programmatic Cost Estimate
Project Costs
Project Assumptions Units Cost Notes
General Assumptions
Staffing Cost - Salary and Benefits $167,000 per FTE Salary + benefits per Palo Alto direction
Project Period 21 years through 2045
Calculations
1) Outdoor Irrigation Efficiency for CII Properties
Phase 1
5
--
Years to Saturation YR
City Staffing Time Needed 0.6 FTE Staff time for technical guidance and landscaping support. No financial incentiveincluded, although customers may utilize the $2/sf turf replacement incentive.
Program Savings Estimate 229.0
45.8
AFY
AFY
City Staff Estimate from Waterfluence Assumes all CII customers come down to irrigation level calculated by WaterFluence.
Savings in 2024
Savings in 2045 229.0
4,351
Note that these savings potentially overlap with Measures #2 and #7. So if all of theseprograms are enacted, total savings will likely be lowerLinear ramp up until program saturation, then constant savings through planning
horizon
AFY
AFTotal Savings
Cost Summary
Annual Staffing Cost $100,200 Staffing costs occur every year until program saturation.
Annual Program Costs
$0
Total Annual Costs $100,200
Lifetime Costs $501,000 Total cost through planning horizon
Unit Cost ($/AF)$115 Total cost through planning horizon/total savings through planning horizon
2) Non-Functional Turf Ban for CII Properties
Phase 1 --
In 2027 the City will have to adopt an ordinance to follow AB1572, this measure goes
beyond the State requirment of not allowing watering non-functional turf and requiresproperties to remove turf and replace it with drought-tolerant plants.
Years to Saturation
10
0.1
YR
FTE
FTE
$
City Staff for Owner Notifications
City Staff for Site Inspections
City Spatial Analysis Survey
0.3
$15,000 Cost per survey
Frequency of Spatial Survey 5 Assume this occurs every 5 years over 10 year saturation period
One time costLegal review/possible challenges
Acreage of turf replaced
$100,000 $
28 acres City Staff Estimate from Waterfluence
City Staff EstimateTurf Replacement Savings Rate 36 gal/sq ft
AF/acre
AFY
Turf Replacement Savings Rate 4.8
Savings in 2024 13.2 Note that these savings potentially overlap with Measures #1 and #7. So if all of theseprograms are enacted, total savings will likely be lower
Linear ramp up until program saturation, then constant savings through planninghorizon
Savings in 2045
Total Savings
132.3 AFY
AF2,184
Cost Summary
Annual Staffing Cost $66,800
$14,500
$81,300
$813,000
$372
Staffing costs occur every year until program saturation.
Annual Program Costs
Total Annual Costs
Lifetime Costs
Annual costs averaged over implementation period (does not include staffing)
Total cost through planning horizon
Unit Cost ($/AF)Total cost through planning horizon/total savings through planning horizon
8
Enhanced Conservation
3) Low Income Residential HET Replacement Program
Phase 1 --
Years to Saturation 10 YR
City Staffing Time Needed
0.05 FTE
Rebate Rate $875 $ / toilet City Staff Estimate, 7/28/23, pg 5 Assumes full cost of toilet replacement is borne by Palo Alto
Number of DUs targeted
200
2
DU
toilet
ccf/yr
AFY
Number of toilets per DU
Savings per Toilet Replacement
Savings per Toilet Replacement
12.19
0.028
City Staff Estimate
Savings in 2024 1.1
Savings in 2045 11.2 AFY
AF Linear ramp up until program saturation, then constant savings through planninghorizonTotal Savings 185
Cost Summary
Annual Staffing Cost
Annual Program Costs
$8,350
$35,000
Total Annual Costs $43,350
Lifetime Costs $433,500 Total cost through planning horizon
Unit Cost ($/AF)$2,347 Total cost through planning horizon/total savings through planning horizon
4) Lawn Limitation for New Development and Major Retrofits
Phase 1 --
Years to Saturation ongoing
0.1
YR
City Staffing - Plan Review FTE
FTECity Staffing - Site Inspections
City Staffing - Enforcement
0.1
0.1
City Staffing - Education & Outreach
0.1
Legal review/possible challenges $100,000
600
$One time cost
Lawn size assumption based on approximate measuring Google Earth lawns and PaloAlto front lawn setback requirementsEstimated size of front lawn replaced sqft
Number of major retrofits per year 100
1.4
36
Palo Alto Development Services estimates 50-100 major remodels per year.
Estimated acreage of front lawns repl
Turf Replacement Savings Rate
Turf Replacement Savings Rate
afy/ac
gal/sq ft
AF/acre
AFY
City Staff Estimate
4.8
Savings in 2024 6.6
Savings in 2045
Total Savings
139.2 AFY
1,531 AF
Cost Summary
Annual Staffing Cost
Annual Program Costs
Total Annual Costs
$66,800
$1,509 Annual costs averaged over implementation period (does not include staffing)
$68,309
Lifetime Costs $1,502,800 Total cost through planning horizon
Unit Cost ($/AF)
5) 3-Day Watering Week
Phase
$981 Total cost through planning horizon/total savings through planning horizon
1 --
Years to Saturation 1 YR
City Staffing - Enforcement 0.1 FTE
City Staffing - Education & Outreach
0.1 FTE
Total Palo Alto Water Use (2020)
Indoor Water Use (2020)
10,722
6,342
4,286
3,282
11%
(Palo Alto, 2021, Table 10)
City Staff 2020 City of Palo Alto Flows to the RWQCP
Outdoor Water Use in 2024 Outdoor water use minus savings assumed from other irrigation programs
Outdoor water use decreases over time as other savings programs take effect
Based on findings from 2022 watering restrictions
Outdoor Water Use in 2045
Irrigation Reduction with 2 Day
Irrigation Reduction with 3 DayWatering Week 5%City Staff
Savings in 2024 214.3
164.1
3,973
AFY
AFY
AF
Savings in 2045
Total Savings
Cost Summary
Annual Staffing Cost
Annual Program Costs
$33,400
$0
Total Annual Costs
Lifetime Costs
$33,400
$701,400
$177
Total cost through planning horizon
Unit Cost ($/AF)Total cost through planning horizon/total savings through planning horizon
6) HET Replacement Program for CII Properties
Phase 2 --
Years to Saturation 10 YR
City Staffing Time Needed 0.3 FTE
$Cost per toilet replacement
Total Employees in Palo Alto
$875 City staff comments 7/28/23, pg 5
(SVI, 2020, pg 5)
Assumes full cost of toilet replacement is borne by Palo Alto
100,000 employees Range: 92,000 to 114,000 in 2018
Assuming that an average commercial toilet lasts 30 years and toilet age is equallydistributed in Palo Alto, 13% of toilets are estimated to be from before 1997, when lowflow toilet laws went into place.
Percentage of Toilets Eligible for
Replacement 13%%
Total Employees Targeted
Employees per Toilet
13,000
17
employees Number of employees who use toilets that are eligible for replacement
employee / toilet (OSHA, 2023, Standard 1910.141( C )(1)(i)) Average required number of toilets per OSHA
Assumes 1 toilet replacement per 17 employees (average required number of toiletsper OSHA)Total Replacements 765
12.19
0.028
2.1
EA
ccf/yr
AFY
AFY
AFY
Savings per Toilet Replacement
Savings per Toilet Replacement
Savings in 2024
City Staff Estimate
Savings in 2045 21.4
Total Savings 353 Linear ramp up until program saturation, then constant savings through planninghorizonAF
Cost Summary
Annual Staffing Cost
Annual Program Costs
Total Annual Costs
Lifetime Costs
$50,100
$66,912
Staffing costs occur every year until program saturation
Program costs occur every year until program saturation
$117,012
$1,170,118
$3,314
Total cost through planning horizon
Unit Cost ($/AF)Total cost through planning horizon/total savings through planning horizon
9
Enhanced Conservation
7) City Landscaping Support for Turf Replacement
Phase 2 --
Years to Saturation
City Staffing Time Needed
ongoing
0.4
YR No saturation within planning horizon given low rate of replacement
FTE
Existing rebate. Valley Water contributes another $2 so customers get a total of $4/sqft.Rebate Rate $2
$2
$ / sqft
$ / sqft
City Staff Estimate
City Staff Estimate
Cost to Help Cover Direct Installation
Acres replaced per year 1.5
36
acres / yr
gal / sq ft
AF/acre
Turf Replacement Savings Rate
Turf Replacement Savings Rate 4.8
Savings in 2024 7.2 AFY
Savings in 2045 151.6
1,668
Note that these savings potentially overlap with Measures #1 and #2. So if all of these
programs are enacted, total savings will likely be lowerAFY
AFTotal Savings
Cost Summary
Annual Staffing Cost
Annual Program Costs
Total Annual Costs
Lifetime Costs
$66,800
$261,360
$328,160
$6,891,360
$4,133
Total cost through planning horizon
Unit Cost ($/AF)Total cost through planning horizon/total savings through planning horizon
8) Lawn Limitation for Residential Properties Upon Resale
Phase 2 --
Years to Saturation Ongoing as turnover rate (400 per year) does not reach all Palo Alto homes (17,900)within planning horizonongoing
0.5
YR
FTE
FTE
FTE
FTE
$
City Staffing - Plan Review
City Staffing - Site Inspections
City Staffing - Enforcement
0.3
0.4
City Staffing - Education & Outreach
Legal review/possible challenges
0.3
$100,000 One time cost
Estimated size of front lawn replaced Lawn size assumption based on approximate measuring Google Earth lawns and PaloAlto front lawn setback requirements600sqft
DUTotal SFR in Palo Alto 17,900 (Palo Alto, 2022b, Table 2-36)
(Homes Directory, 2023)Average SFR sold per year 2014-2022 per "New Homes Directory". May double-countretrofitted homes considered in Measure #6Houses turned over per year 400
80%
4.4
DU/yr
%Expected Compliance (%)
Estimated acreage of front lawns repl
Turf Replacement Savings Rate
Turf Replacement Savings Rate
acres
gal/sq ft
AF/acre
36 City Staff Estimate
4.8
Savings in 2024 21.2
445.5
4,900
AFY
AFY
AF
Savings in 2045
Total Savings
Cost Summary
Annual Staffing Cost
Annual Program Costs
Total Annual Costs
Lifetime Costs
$250,500
$236,818
$487,318
$5,360,500
$1,094Unit Cost ($/AF)
Phase 1 Total
Average Annual Cost
Average Annual Project Yield
Unit Cost ($/AF)
$188,176
582
$323
Phase 2 Total
Average Annual Cost
Average Annual Project Yield
Unit Cost ($/AF)
$639,142
330
$1,939
1) Measures 1, 2, and 7 target outdoor irrigation and may have some overlap, leading to a reduction in total expected savings from those programs if they are all implemented.
2) Similar to Note #4, Measures 7 and 8 target residential front lawns and may overlap, leading to a reduction in total expected savings if they are both implemented. For example, if a customer first renovates a house and then sells it, there wouldnot be savings from the sale as the front lawn would have already been removed.
10
Enhanced Conservation
Water Conservation Program Summary by Best Management Practice
Phase Best Management Practice Description Total YieldThrough 2045(af)
Unit Cost($/AFY)Program Cost
1
1
1
1) Outdoor Irrigation Efficiency for CII Properties
2) Non-Functional Turf Ban for CII Properties
3) Low Income Residential HET Replacement Program
4,351 $501,000
$813,000
$433,500
$115
$3722,184
185 $2,347
1 4) Lawn Limitation for New Development and Major Retrofits
5) 3-Day Watering Week
1,531
3,973
12,224
353
$1,502,800
$701,400
$981
$1771
Phase 1 Subtotal $3,951,700
$1,170,118
$6,891,360
$323
2
2
6) HET Replacement Program for CII Properties
7) City Landscaping Support for Turf Replacement
$3,314
$4,1331,668
2 8) Lawn Limitation for Residential Properties Upon Resale 4,900
6,921
$5,360,500
$13,421,978
$17,373,678
$1,094
$1,939
$907
Phase 2 Subtotal
Water Conservation Program Summary 19,145
Project Yield and Cost
8) Lawn Limitation for
Residential Properties UponResale
1) Outdoor Irrigation Efficiency for CII 3) Low Income Residential HET Replacement
Program
4) Lawn Limitation for New Development
and Major Retrofits
6) HET Replacement Program for CII
Properties
7) City Landscaping Support for Turf
ReplacementYear2) Non-Functional Turf Ban for CII Properties 5) 3-Day Watering Week Phase 1 Total Phase 2 TotalProperties
CY Count Yield
46
Cost Yield
13
Cost Yield Cost Yield
7
Cost Yield Cost Yield Cost Yield
7.2188
14
Cost Yield
21
Cost Yield
281
345
410
474
Yield
312025
2026
2027
2028
1
2
3
4
$100,200
$100,200
$100,200
$100,200
$181,800
$66,800
$66,800
$66,800
1
2
3
4
$43,350
$43,350
$43,350
$43,350
$166,800
$66,800
$66,800
$66,800
214
212
209
207
$33,400
$33,400
$33,400
$33,400
2
4
6
9
$117,012
$117,012
$117,012
$117,012
$328,160
$328,160
$328,160
$328,160
$350,500
$250,500
$250,500
$250,500
92 26 13 42 61
137
183
40 20 22 64 92
53 27 29 85 122
2029 5 229 $100,200 66 $81,800 6 $43,350 33 $66,800 204 $33,400 11 $117,012 36 $328,160 106 $250,500 538 153
2030
2031
6
7
229
229
$0
$0
79
93
$66,800
$66,800
7
8
$43,350
$43,350
40
46
$66,800
$66,800
202
199
$33,400
$33,400
13
15
$117,012
$117,012
43
51
$328,160
$328,160
127
148
$250,500
$250,500
557
575
183
214
2032 8 229 $0 106 $66,800 9 $43,350 53 $66,800 197 $33,400 17 $117,012 58 $328,160 170 $250,500 594 245
2033 9 229 $0 119 $66,800 10 $43,350 60 $66,800 194 $33,400 19 $117,012 65 $328,160 191 $250,500 612 275
2034
2035
10
11
229
229
$0
$0
132
132
$81,800
$0
11
11
$43,350
$0
66
73
$66,800
$66,800
192
189
$33,400
$33,400
21
21
$117,012
$0
72
79
$328,160
$328,160
212
233
$250,500
$250,500
631
635
306
334
2036 12 229 $0 132 $0 11 $0 80 $66,800 187 $33,400 21 $0 87 $328,160 255 $250,500 639 363
2037
2038
13
14
229
229
$0
$0
132
132
$0
$0
11
11
$0
$0
86
93
$66,800
$66,800
184
182
$33,400
$33,400
21
21
$0
$0
94 $328,160
$328,160
276
297
$250,500
$250,500
643
647
391
419101
2039 15 229 $0 132 $0 11 $0 99 $66,800 179 $33,400 21 $0 108 $328,160 318 $250,500 651 448
2040
2041
16
17
229
229
$0
$0
132
132
$0
$0
11
11
$0
$0
106
113
$66,800
$66,800
177
174
$33,400
$33,400
21
21
$0
$0
116
123
$328,160
$328,160
339
361
$250,500
$250,500
655
659
476
505
2042 18 229 $0 132 $0 11 $0 119 $66,800 172 $33,400 21 $0 130 $328,160 382 $250,500 664 533
2043
2044
2045
19
20
21
229
229
229
$0
$0
$0
132
132
132
$0
$0
$0
11
11
11
$0
$0
$0
126
133
139
$66,800
$66,800
$66,800
169
167
164
$33,400
$33,400
$33,400
21
21
21
$0
$0
$0
137
144
152
$328,160
$328,160
$328,160
403
424
445
$250,500
$250,500
$250,500
668
672
676
562
590
618
Total 4,351 $501,000 2,184 $813,000 185 $433,500 1,531 $1,502,800 3,973 $701,400 353 $1,170,118 1,668 $6,891,360 4,900 $5,360,500 12,224 6,921
11
Irrigation Wells
Irrigation Wells
Cost Estimate Summary Table
Project
Total Capital Cost
Capital Cost
Cost Units
$1,000,000
$0
$
Land Acquisition Cost
Amortized Capital and Land Cost
Total O&M Cost
Groundwater Production Charge (GPC)
O&M Cost
$M
$65,051 $ per Year
$93,096
$6,822
$3,276
$ per Year
$ per Yr
Energy Cost $ per Yr
Total Unit Cost
Total Annual Cost
Project Yield
$168,246
54
$ per AF
AFY
Capital Cost Unit Cost
GPC Unit Cost
$1,205
$1,724
$126
$ per AF
$ per AF
$ per AF
$ per AF
$ per AF
O&M Unit Cost
Energy Unit Cost $61
Unit Cost $3,116
Cost Escalation
Period ENR Date
ENR Index (Northwest County RecycledWater Strategic Plan, TechnicalMemorandum 6.4, December 2020)Current Cost Basis
13,169
15,490
December 2020
September 2023
Cost Escalation Method
Capital Costs Project Quantity Unit Unit Cost Original Cost Current Cost Source NotesAdjustmentsConstruction Cost
Construction Cost Per Well 5 EA $75,000 $375,000
$844,220
(W&C, 2019, TM 6.4, Table 5, pdf pg 11)
Construction Cost Markup
Capital Cost
2.25 Added construction cost markup since it was not clearly included in original cost.$168,844 $993,011
SubtractionsTreatment Facilities
Conveyance
Storage
Pump Stations
Other
Additions
Treatment Facilities
Conveyance
Storage
Pump Stations
Other
Total Capital Cost
Original Total $375,000 $993,011
Subtractions
Additions
--
--
$0
$0
Calculated Total
Capital Cost Total (Rounded)
--
--
$993,011
$1,000,000
O&M Cost
Project Quantity Unit Unit Cost Original Cost Current Cost Source Notes
Adjustments
O&M Cost
Original O&M wo GW Production Charge
Original Groundwater Production Charge
$5,800 $6,822 (W&C, 2019, TM 6.4, Table 6, pdf pg 11)
$105,000
--
--(W&C, 2019, TM 6.4, Table 6, pdf pg 11)
(Valley Water, 2022)New Groundwater Production Charge 54 $/AF $1,724 $93,096
Subtractions
Treatment
Conveyance Pipelines
Pump Station(s)
Storage
Other
Additions
Treatment
Conveyance Pipelines
Pump Station(s)
Storage
Other Energy Cost for Pumping
O&M Total
45,000 Kwh $0.10 $9,000 $3,276.19 City Staff Estimate
O&M Subtotal $119,800 $99,918
$0Subtractions
Additions $3,276
Calculated O&M Total $110,800 $103,194$110,000Total O&M Cost (Rounded)
12
Groundwater
Emergency Well Conversion
Cost Estimate Summary Table
Iron (Fe)/Manganese(Mn)/Total Dissolved Solids(TDS) Treatment
Difference (TreatmentCost (Option 4) -Blending Cost (Option1))
El Camino Only with Fe/Mn/TDSTreatment El Camino OnlyBlending (Option1B)
Blending(Option 1)(Option 4B)(Option 4)Cost Units
Total Capital Cost
Capital Cost $49,760,760
$0
$1,532,363
$0
$48,228,398
$0
$25,472,442
$0
$0
$0
$0
$
$Land Acquisition Cost
Amortized Capital and Land Cost
Total O&M Cost
Groundwater Production Charge (GPC)
O&M Cost
$3,408,068 $92,395 $3,315,673 $1,788,376 $ per Year
$5,172,000
$1,811,749
$99,964
$5,172,000
$212,010
$99,964
$0
$1,599,739
$0
$4,137,600
$1,362,069
$74,426
$4,137,600
$169,608
$74,426
$ per Year
$ per Year
$ per YearEnergy Cost
Total Unit Cost
Total Annual Cost
Project Yield
$10,491,781 $5,576,369 $4,915,412 $7,362,471 $4,381,634 $ per Yr
AFY2,250 3,000
$31
1,800
$994
2,400
$0Capital Cost Unit Cost
GPC Unit Cost
$1,515 $1,484
$575
$ per AF
$ per AF
$ per AF
$ per AF
$ per AF
$2,299
$805
$1,724
$71
$2,299
$757
$1,724
$71O&M Unit Cost $735
Energy Unit Cost $44 $33 $11 $41 $31
Unit Cost $4,663 $1,859 $2,804 $4,090 $1,826
Cost Escalation
Period ENR Date
ENR Index (Carollo Groundwater Study, May 2000)Current Cost Basis
7,164 May, 2000
15,490 September 2023
Cost Escalation Method
Capital Costs Project Quantity Unit Unit Cost Original Cost Current Cost Source Notes
Construction Cost
Original Construction Cost varies by Option. See Summary Table for Options 1-4 above (Column L-R).AdjustmentsLand Acquisition
Original Land Acquisition
n/a (no land needed for the 2 selected wells)Revised Land Acquisitionn/aSubtractions
Treatment Facilities
n/a
Conveyancen/aStorage
n/a
Pump Stations
n/a
Other
n/aAdditionsTreatment Facilitiesn/a (already included in 2000 Study)
Conveyance
Option 4: Brine line for RO waste stream
Brine line flowrate assumption for Fe/Mn filter backwashing
Brine line flowrate assumption for RO treatment
Brine line flowrate assumption Total
5%
20%
25%
372
250
622
5
of Q_well
of Q_well
of Q_well
gpmBrine line flowrate El Camino Well (1488 gpm)
Brine line flowrate Eleanor Pardee Park Well (372 gpm)
Brine line flowrate (both wells)
gpm
gpm
Design velocity ft/sec Assumes pressurized flow of brine to RWQCP outfall
Brine Line El Camino to Eleanor Pardee Park @ 1000 gpm
Brine Line Eleanor Pardee Park to RWQCP @1000 gpm
Brine Line El Camino to Eleanor Pardee Park @1488 gpm
Brine Line Eleanor Pardee Park to RWQCP @1000 gpm
4.5
6.0
6.0
8.0
inches
inches
inches
inches
9,000
10,600
9,000
feet
feet
feet
feet
$
$
$
$
10,536,000
13,364,000
11,347,000
14,796,000
Assumes dedicated brineline is needed (most conservative)
Assumes dedicated brineline is needed (most conservative)
Assumes dedicated brineline is needed (most conservative)
Assumes dedicated brineline is needed (most conservative)10,600
Storage
Options 2, 3, 4: Backwash water storage for Fe & Mn treatment (2 sites)
Backwash volume
Backwash duration
Backwash frequency
5
15
1
times Q_well
mins/cycle
time per day
Options 2 and 4 (El Camino = 1,488 gpm & Eleanor Pardee = 372 gpm)
Daily backwash volume El Camino Well @ 1,488 gpm 0.11
0.08
5.5
MG
MG
$1.00
$1.00
1,500
830
n/a
n/a
$
$
$
$
251,229
168,844
Check backwash volume is approximately 5% of treatment flow (5%*1488 gpm = 748 gpm = 0.107 mgd
Check backwash volume is approximately 5% of treatment flow (5%*372 gpm = 19 gpm = 0.027 mgdDaily backwash volume Eleanor Pardee Well @ 1000 gpm
Sewer Connection from Camino Well to sewer (25%*1488=372 gpm)
Sewer Connection from Eleanor Pardee Well to sewer (25%*1000=250 gpm)
inches
inches
feet
feet
1,891,052 ###########################################
971,641 ###########################################A
A
dedicated brineline is used (15% cheaper in $/AF than sewer connections w/charges)
dedicated brineline is used (15% cheaper in $/AF than sewer connections w/charges)4.5
Option 3 (El Camino = 613 gpm& Eleanor Pardee = 524 gpm)
Backwash volume El Camino Well @ 613 gpm 0.05
0.04
3.5
MG
MG
$1.00
$1.00
1,500
830
n/a
n/a
$
$
$
$
103,478
88,501Backwash volume Eleanor Pardee Well @ 524 gpm
Sewer Connection from Camino Well to sewer (25%*613=153 gpm)
Sewer Connection from Eleanor Pardee Well to sewer (25%524=131 gpm)Options 4B (El Camino = 1,488 gpm)
inches
inches
feet
feet
1,755,977 ########################################### gpm on average
971,641 ########################################### gpm on average3.5
Backwash volume El Camino Well @ 1,488 gpm
Sewer Connection from Camino Well to sewer (25%*1488=372 gpm)
Pump Stations (Option 4 only)
0.11
5.5
MG $1.00
1,500
n/a $
$
251,229
inches feet 1,891,052 ########################################### gpm on average
Brine PS at El Camino Well @ 1000 gpm
Brine PS at El Camino Well @ 1488 gpm
Brine PS at Eleanor Well @ 1000 gpm
1
2
1
hp
hp
hp
20
20
20
feet TDH
feet TDH
feet TDH
$
$
$
26,015
38,708
26,015
Assumes pressurrized flow of brine to RWQCP outfall
Assumes pressurrized flow of brine to RWQCP outfall
Assumes pressurrized flow of brine to RWQCP outfall
Sewer Connection Fees (not used)
Sewer Connection Charge El Camino Well 1
1
connection
connection
$
$
9,846
9,846
$
$
9,846
9,846
WASTEWATER SERVICE CONNECTION CHARGES UTILITY RATE SCHEDULE S-5
WASTEWATER SERVICE CONNECTION CHARGES UTILITY RATE SCHEDULE S-5Sewer Connection Charge Eleanor Pardee Park Welln/a
13
Groundwater
O&M Cost
Project Quantity Unit Unit Cost Original Cost Current Cost Current Scaled Capacity Cost (2023)Source
Adjustments
O&M Cost
Original Annual O&M: Option 1 $
$
$
$
$
1,084,968
542,484
$
$
$
$
$
5,907,548 $
$
$
5,483,974
Original Annual O&M: Option 1B (El Camino Well with blending only)
Original Annual O&M: Option 2
2,944,458
5,997,959
2,201,372
7,162,610
4,381,634
7,413,618
n/a
1,121,459
429,768Original Annual O&M: Option 3
Original Annual O&M: Option 4 1,606,063 $7,083,713Subtractions
Treatment
2023 Cost of Chlorine per 1000 gpm well $
$
13,931
12.5%
1,741
per year Palo Alto staff estimate based on (AWWA, 2023) that the amount of ammonia required is 1/8 to 1/12 the ammount ofChlorine. This estimate assumes the escalated cost of chemicals from the 2000 Carollo Study to be the cost of ammoniamultiplied by (1/8) to get the cost of ammonia treatment.2024 Cost of Ammonia compared to Chlorine per 1000 gpm well -
2023 Cost of Ammonia per 1000 gpm well
Conveyance Pipelines
per year
n/aPump Station(s)n/aStorage
n/a
Other n/aAdditionsTreatment
n/a
Conveyance Pipelinesn/aPump Station(s)neglible
Storage
n/a
Other
Annual Energy Cost for Groundwater pumping El Camino Well 204
280
ft
ft
1,488
372
gpm
gpm
$
$
50,014
68,647
$74,426
$25,538
(Todd Groundwater, 2018, Table 4-2)
(Todd Groundwater, 2018, Table 4-2)Annual Energy Cost for Groundwater pumping Eleanor Pardee Park Well
Annual Energy Cost for 2 wells pumping all year
Groundwater Production Charges (El Camino only)
Annual Sewer ServiceCharge for Option 4- El Camino RO Brine
Annual Sewer ServiceCharge for Option 4- Eleanor RO Brine
Annual Sewer Service Charge for Option 4- El Camino Backwash
Annual Sewer Service Charge for Option 4- Eleanor Backwash
Capacity Charge El Camino
$99,964
2,400
$209,088
$52,272
$52,272
$13,068
afy
ft^3
ft^3
ccf
1,724 $/AF (2023 dollars)$4,137,600
$1,898,515
$474,629
$474,629
$118,657
9.08
9.08
9.08
9.08
$/ccf
$/ccf
$/ccf
$/ccf 44. COMMERCIAL WASTEWATER COLLECTION AND DISPOSAL UTILITY RATE SCHEDULE S-2ccf
Capacity Charge Eleanor
Backwash Water El Camino SFPUC Cost 125
84
afy
afy
$2,069
$2,069
$/AF
$/AF
$258,635
$173,822Backwash Water Eleanor SFPUC Cost
Energy Cost for brine pumping neglibable
O&M Total
Original Total
Subtractions
$542,484
--
$2,944,458 $4,381,634
----
Additions $50,014
$592,498
$50,014
$2,994,472
$74,426
$4,456,059Calculated Total
O&M Cost Total (rounded)$593,000 $2,995,000 $4,457,000
14
Groundwater
SUPPORTING CALCULATIONS BY OPTION (updating costs from the 2000 Carollo Study)
Option 1 - Blending with SFPUC Water Capacity set to not exceed 3,000 afy (ToddGroundwater, 2018)Description Original Cost (1)Cost Adjustment 2000 -> 2023 Escalated Cost Estimate ($2023)Capacity Scaling in 2023 dollarsFLOW CAPACITY/YIELD
GW Production CapacitySFPUC FlowTotal GW Yield (1,2)CAPITAL COSTFlow Control
El Camino (1)Eleanor (1)Quantity Unit El Camino Eleanor El Camino (2)Eleanor (2)gpmgpmAFY
1,0003,1001,613
1,0003,1001,613
1,4884,6132,400
3721,1536001,613 1,613 149%in-place
in-place
37%$$$$75,000100,000 $$75,000100,000 216% ENR ratio216% ENR ratio in-placein-place $$162,165216,220 $$60,32980,439Blending Facility(3)
Pipeline $$
$
$
$
50,000
225,000
21,238
42,461
n/a
$
$
$
$
1,730,000
1,905,000
179,819
42,461
n/a
216% ENR ratio in-place $
$
$
$
$
$
$
$
$
$
3,740,606
4,118,991
248,358
113,977
68,647
in-place $
$
$
$
$
$
$
$
$
$
1,391,594
1,532,363
92,395
CAPEX Subtotal $
$
$
$
$
$
$
$
$
-
-
$
$
$
$
$
$
$
$
$
-
Annualized Capital Costs $/Yr -
OPERATION & MAINTENANCE COST
Energy Cost for GW pumping
OPEX Subtotal
268% labor multiplier
1,724 $/AF (2023 dollars)
113,977
50,014
163,991
2,780,467
2,944,458
1,826
169,608
74,426
42,402
$/Yr 25,538
$/Yr $
$
$
$
$
42,461
500,023
563,722
350
$
$
$
$
$
42,461
500,023
722,303
448
182,623
2,780,467
3,211,449
1,991
244,034
4,137,600
4,381,634
1,826
67,940
GROUNDWATER PRODUCTION CHARGE
Total Annual Cost
$1,034,400
1,194,735
1,991
$/yr
Unit GW Production Cost
GW production cost without GW Production Charge
$/afy
39 138 102 267 102 267
1) Production Capacity from (Todd Groundwater, 2018, Appendix B Cost Estimates)2) Increase production capacity for El Camino Well from Todd Groundwater, 2018
3) Addition of chelate recommended to keep Fe and Mn in solution.
Option 2 - Fe and Mn Treatment at Each Well
Description
Exceeds 3000 afy (Todd Groundwater, 2018)
Capacity Scaling in 2023 dollarsOriginal Cost (1)
El Camino (1)
Cost Adjustment 2000 -> 2023 Escalated Cost Estimate ($2023)
FLOW CAPACITY/YIELD
GW Production Capacity
SFPUC Flow
Eleanor (1)Quantity Unit El Camino
1,000
0
Eleanor El Camino (2)Eleanor (2)
1,000gpmgpmAFY
1,000-1,000-1,0000 1,4880 0Total Yield (1,2)1,613 1,613 1,613 1,613 2,400 1,613
CAPTIAL COST 149%100%
Pressurized Filters $
$$
$900,000
n/a
$900,000
n/a
216% multiplier $
$$$
$
1,945,980
251,229
$
$$$
$
1,945,980
168,844
$
$$$
$
2,895,490
251,229
$
$$
1,945,980
168,844Backwash Storage Tank (3)Sewer Connection (3)CAPEX Subtotal n/a n/a 1,891,0522,197,209
176,310
1,891,0522,114,824
169,699
1,891,0525,037,771
357,190
1,891,0524,005,876
276,197
$900,000
84,954
$900,000
84,954
$
Annualized costs $/Yr $$$
OPERATION & MAINTENANCE COST
Operating Cost $/Yr$/Yr$/Yr
$/Yr
$/Yr
$/Yr$/Yr
$42,461n/a $42,461n/a 268% labor multiplier $$$
$
$
$$
113,97750,0142,509
2,999
13,931
143
$$$
$
$
$$
113,97768,6472,509
2,999
13,931
143
$$$
$
$
$$
169,59074,4263,733
4,462
20,729
214
$$$
$
$
$$
113,97725,5382,509
2,999
13,931
143
Energy Cost for GW pumpingEnergy Cost for treatment
Replacement Media
Chemicals
$
$
$
$$
1,506
1,254
5,825
60
$
$
$
$$
1,506
1,254
5,825
60
167% energy multiplier
239% materials
239% materials
Repair Valve Kits 239% materialsReplacement Valves 500 500 239% materials 1,196 1,196 1,779 1,196Personnel Costs $/Yr $9,100 $9,100 268% labor multiplier $24,427 $24,427 $36,345 $24,427OPEX Subtotal $/Yr $60,706 $60,706 $209,196 $227,829 $311,278 $184,720
GROUNDWATER PRODUCTION CHARGETotal Annual Cost $$500,023645,683 $$500,024645,684 $1,724 $/AF (2023 dollars)$$2,780,4673,165,973 $$2,780,4673,177,995 $$4,137,1524,805,620 $$2,780,4673,241,385$/yr
Unit GW Production Cost $/afy $400 $400 $1,963 $1,970 $2,003 $2,010GW production cost without GW Production Charge $90 $90 $239 $246 $279 $2861) Production Capacity from (Todd Groundwater, 2018, Appendix B Cost Estimates)
2) Increase production capacity for El Camino Well from Todd Groundwater, 2018
3) Backwash tank sized to avoid large flow rate with Fe and Mn backwash water. Assumed that backwash water has sufficient pressure to drain to nearby sewer by gravity.
15
Groundwater
Option 3 - Fe and Mn Treatment at Each Well plus BlendingDescription Original Cost (1)Cost Adjustment 2000 -> 2023 Escalated Cost Estimate ($2023)Capacity Scaling in 2023 dollarsFLOW CAPACITY/YIELD El Camino (1)Eleanor (1)Quantity Unit El Camino Eleanor
GW Production CapacitySFPUC Flow gpmgpm 3803,720 3253,775 3803,720 325 Not scaled as the wells are already3,775 underutilized in 2000 Study.
Total Yield (1,2)AFY 613 524 613 524 No information available onCAPTIAL COST upscaling with blending.Pressurized FiltersFlow ControlBlending Facilities
$$$$$$
700,00075,000100,00030,000n/an/a905,00085,426
700,00075,000100,0001,150,000n/an/a2,025,000191,146
216% multiplier216% multiplier216% multiplier216% multiplier
$$$$$$$$
1,513,540162,165216,22064,866103,4781,755,9773,816,246263,959
$$$$$$$$
1,513,540162,165 This alternative is not carried forward216,220 and out of scope to analyze this further.Pipelines 2,486,53088,5011,755,9776,222,933404,216
Backwash Storage Tank (3)Sewer Connection (3)CAPEX SubtotalAnnualized costsOPERATION & MAINTENANCE COSTOperating CostEnergy Cost for GW pumpingEnergy Cost for treatmentReplacement MediaChemicals
$/Yr
$/Yr$/Yr$/Yr
20,381n/a1,5061,2545,82560
20,381n/a1,5061,2545,82560
268% labor multiplier $$$$$$$
54,70819,0052,5092,99913,931143
$$$$$$$
54,70822,3102,5092,99913,931143
167% energy multiplier239% materials239% materials239% materials239% materials
$/Yr$/Yr$/YrRepair Valve KitsReplacement Valves 500 500 1,196 1,196
Personnel Costs $/Yr 9,100 9,100 268% labor multiplier $24,427 $24,427OPEX Subtotal 38,626 38,626 $118,919 $122,224
Groundwater Production Charge
Total Annual Cost
190,009
314,061
512
162,507
392,279
748
$1,724 $/AF (2023 dollars)$
$
$
$
1,056,578
1,439,455
2,349
$
$
$
$
903,652
1,430,091
2,728
$/yr $
$
$
$
$
$
Unit GW Production Cost $/afyGW production cost without GW Production Charge 202 438 625 1,0041) Production Capacity from (Todd Groundwater, 2018, Appendix B Cost Estimates)
2) Increase production capacity for El Camino Well from Todd Groundwater, 2018
3) Backwash tank sized to avoid large flow rate with Fe and Mn backwash water. Assumed that backwash water has sufficient pressure to drain to nearby sewer by gravity.
Capacity set to not exceed (3,000 afy) (ToddGroundwater, 2018)Option 4 - Fe, Mn, and TDS + Ammonia Treatment at Each WellDescription Original Cost (1)Cost Adjustment 2000 -> 2023Quantity Escalated Cost Estimate ($2023)Capacity Scaling in 2023 dollarsFLOW CAPACITY/YIELD
GW Production Capacity
SFPUC Flow
El Camino Eleanor Unit El Camino
1,000
0
Eleanor El Camino (2)Eleanor (2)
gpm
gpm
AFY
1,000 1,000
-
1,000 1,488
2,400
372
600
-0 0 0
Total Yield (1,2)1,613 1,613 1,613 1,613CAPTIAL COST
Pressurized FiltersRO system
149%37%$$$
900,0003,400,000n/a
900,0003,400,000n/a
216% multiplier216% multiplier $$1,945,9807,351,480n/a
$$1,945,9807,351,480n/a
$$$
2,895,80310,939,702251,229
$$$
1,945,9807,351,480168,844Backwash Storage Tank (3)
Sewer Connection (3)Brine Disposal Pipeline (4)Brine Disposal PS (4)CAPEX SubtotalPressurized FiltersRO system
$$$
n/an/an/a4,300,00084,960320,936n/a
n/an/an/a4,300,00084,960320,936n/a
n/an/an/a9,297,460156,150589,902-
n/an/an/a9,297,460156,150589,902-
$$$$$$$
11,347,00038,70825,472,442232,367877,830678,179
$$$$$$$
14,796,00026,01524,288,318156,150589,902873,640
$$$
$$$
$$$$$
$$$$$
$/Yr$/YrOther including Brine Disposal PipelineAnnualized costs $405,896 $405,896 746,052 746,052 1,788,376 1,619,692OPERATION & MAINTENANCE COSTWell Operating CostPressurized Filters O&M CostEnergy Cost for GW pumpingEnergy Cost for treatmentReplacement MediaAmmoniaChemicalsRepair Valve KitsReplacement ValvesPersonnel Costs
$/Yr 42,461 42,461 268% labor multiplier $113,977 $113,977 $169,608 $42,402
$/Yr$/Yr$/Yr$/Yr$/Yr$/Yr$/Yr$/Yr
n/a1,5061,254n/a5,82560
n/a1,5061,254n/a5,82560
$$$$$$$$
50,0143,6022,9991,74113,931143
$$$$$$$$
68,6473,6022,9991,74113,931143
$$$$$$$$
74,4265,3604,4632,59120,731214
$$$$$$$$
25,5381,3401,1166485,18353
167% energy multiplier239% materialsn/a239% materials239% materials239% materials268% labor multiplier
n/a
5009,100 5009,100 1,19624,427 1,19624,427 1,77936,349 4459,087Subtotal$/Yr 18,245 18,245 98,053 116,686 $145,913 $43,410
RO O&M Cost
Energy Cost 83,255 83,255 167% energy multiplier
239% materials
$
$
199,113
380,378
$
$
199,113
380,378
$
$
296,300
566,039
$
$
74,075
Other O&M Cost $/Yr$/Yr$/Yr
$/Yr
$/Yr
$/Yr
159,047 159,047 141,510Annual Sewer Service Charge for Option 4 BrineAnnual Sewer Service Charge for Option 4 Backwash
Capacity Charge $
$
-
258,6351,436,4954,137,6007,362,471
3,068
$
$
-
173,822475,2181,034,4003,129,310
5,216
Backwash Water SFPUC CostOPEX SubtotalGROUNDWATER PRODUCTION CHARGE
Total Annual Cost
303,008500,0231,208,927
750
303,008500,0241,208,928
750
791,5222,780,4674,318,0412,677
810,1542,780,4674,336,6742,689
$$
$
$
$$
$
$
$1,724 $/AF (2023 dollars)$$$
$
$$$
$
$$$
$
$$$
$
$/yr
Unit GW Production Cost
GW production cost without GW Production Charge
$/afy
440 440 953 965 1,344 3,492
1) Production Capacity from (Todd Groundwater, 2018, Appendix B Cost Estimates)2) Increase production capacity for El Camino Well from Todd Groundwater, 2018 with sewer discharge option 3827 4855
3) Backwash tank sized to avoid large flow rate with Fe and Mn backwash water. Assumed that backwash water has sufficient pressure to drain to nearby sewer by gravity.
4) Brine disposal line from El Camino Well to Eleanor Park (segment 1), and then to RWQCP (segment 2) sized for cumulative flow loads at 5 ft/s. Distances see map on next page.
16
Groundwater
Brine Pipeline to RWQCP for TDS removal options (3.7 miles)From El Camino Park to Eleanor Park:1.7 miles2.0 miles 9000 ftFrom Eleanor Pardee Park to RWQCP:10600 ft
17
Palo Alto DPR
Palo Alto DPR
Cost Estimate Summary Table
Project Cost Units
Total Capital Cost
Capital Cost $105,257,000
$11,463,000
$7,592,804
$
$Land Acquisition Cost
Amortized Capital and Land Cost
Total O&M Cost
Groundwater Production Charge (GPC)
O&M Cost
$ per Year
$0 $ per Year
$ per Yr$9,305,267
$74,733Energy Cost $ per Yr
Total Unit Cost
Total Annual Cost
Project Yield
$16,972,804
4,723
1,608
0
$ per AF
AFY
Capital Cost Unit Cost
GPC Unit Cost
$ per AF
$ per AF
$ per AF
$ per AF
$ per AF
O&M Unit Cost 1,970
16Energy Unit Cost
Unit Cost 3,594
Cost Escalation
Period ENR Date
ENR Index (NW County RWSP, June 2018)
Current Cost Basis
12,015
15,490
June 2018
September 2023
Cost Escalation Method
Capital Costs
Project Quantity Unit Unit Cost Original Cost Current Cost Source Notes
Adjustments
Note that the primary source document for this supply option (W&C, 2019) wasprepared prior to the release of final state regulations for DPR.
Total capital cost ($104.6M) minus land acquisition ($25M).
Capital Cost - Reduced Project Yield
Original Project Yield
Revised Project Yield
Land Acquisition
4.73
4.22
MGD
MGD
$16,834,448
$16,834,448
$79,600,000
--
--(W&C, 2019), Option D1, pdf pg 134
$91,512,299 Capital cost escalated to 2023 and yield decreased.
Original Land Acquisition 50,000
57,315
sq ft
sq ft
$500
$200
$25,000,000
--
--(W&C, 2019), Option D1, pdf pg 134
City Staff EstimateRevised Land Acquisition
Subtractions
$11,463,000
Treatment Facilities RO Concentrate treatment removed per direction of City, assuming RO Concentratetreatment not needed under current discharge permit.Removal of RO Concentrate Treatment Costs (W&C, 2019), Option D1, pdf pg 134
(W&C, 2019), Option D1, pdf pg 134
1.18 MGD $1,510,000 $1,784,971
$1,552,925
($2,301,223)
($2,879,412)Construction Cost Markup
Conveyance
0.870 multiplier (W&C, 2019) multiplier used to remove (W&C, 2019) -based cost
Original HDPE Pipeline: 12 inch
Original HDPE Pipeline: 20 inch
Original HDPE Pipeline: 24 inch
5,000
500
lf
lf
lf
$254
$334
$381
$462
$1,270,000
$167,000
$533,400
($1,637,312)
($215,300)
($687,671)
Original pipeline costs from (W&C, 2019) removed in order to use updated pipelinecosts(W&C, 2019), Option D1, pdf pg 1341,400
Original HDPE Pipeline: 30 inch
Construction Cost Markup
2,600
0.870
lf $1,201,200
$2,759,292
($1,548,613)
($3,557,339)multiplier (W&C, 2019) multiplier used to remove (W&C, 2019)-based cost
Storage
n/aPump Stations
n/a
Other
n/aAdditions
Treatment Facilities
Cost scaling factor applied to water stabilization and secondary UV. Vendor quotesused for scaling include equipment only. Estimated adder accommodates installationand required structural and mechanical work.
Cost Scaling Factor 2.0 --
Assuming 30% flow through calcite contactor, based on recent similar projectestimates.Water Stabilization (Calcite Contactor)
Addition of Secondary UV
1.26 MGD $920,000
$100,200
--
--
$2,327,513 (Carollo, 2023a)
(Carollo, 2023a)4.22 MGD $844,988
Construction Cost Markup
Conveyance
1.448 multiplier $4,595,185
Pipeline: 12 inch 5,000
500
lf
lf
lf
$740.00
$960.00 --
--
--
--
$3,700,000
$480,000 (W&C, 2019), Option D1, pdf pg 134
(W&C, 2019), Option D1, pdf pg 135
(W&C, 2019), Option D1, pdf pg 136
(W&C, 2019), Option D1, pdf pg 137
Pipeline: 20 inch
Pipeline: 24 inch 1,400 $1,010.00
$1,060.00
$1,414,000
Pipeline: 30 inch
Construction Cost Markup
Storage
2,600
1.251
lf $2,756,000
$10,447,958multiplier
n/a
Pump Stations
n/aOthern/a
Total Capital Cost
Capital Cost $79,600,000 $91,512,299
$11,463,000
$102,975,299
($12,826,870)
$26,565,644
$116,714,073$116,720,000
Land Acquisition
Original Total
Subtractions
Additions
$25,000,000
$104,600,000
--
--
Calculated TotalCapital Cost Total (rounded)--
18
Palo Alto DPR
O&M Cost Project Quantity Unit Unit Cost Original Cost Current Cost Source Notes
Adjustments
O&M Cost - Reduced Project Yield
Original Project Yield 4.73
4.22
MGD
MGD
$1,694,019
$1,694,019
$8,010,000
--
--(W&C, 2019), Option D1, pdf pg 135
Revised Project Yield $9,208,713 O&M cost escalated to 2023 and yield decreased due to decreased RWQCP flows
Subtractions
Treatment
RO Concentrate treatment removed per direction of City, assuming RO Concentratetreatment not needed under current discharge permit.Removal of RO Concentrate Treatment Costs 1.18 MGD $226,000 ($267,155)($344,422)(W&C, 2019), Option D1, pdf pg 135
Conveyance Pipelinesn/aPump Station(s)
n/aStorage
n/a
Other
Original Energy Costs
Additions
718,547 KWh/yr $0.15 ($107,782)City Staff
Treatment
of annual CAPEX(not including landacquisition)Calcite Contactor
Secondary UV
4%
4%
$6,847,119
$6,847,119
$273,885
$273,885
Estimated as 4% of annual capital cost. Operating costs for calcite contactors include
stabilization chemicals (calcite, sodium hypochlorite) and a small amount of power.
of annual CAPEX(not including landacquisition)
Estimated as 4% of annual capital cost. Operating costs for secondary UV includepower and lamp replacement.
Conveyance Pipelinesn/a
Pump Station(s)
n/aStorage
n/aOther
718,547 KWh/yr is from the Recycled Water Strategic Plan, city staff provided the costper KWhEnergy Costs $0.10718,547 KWh/yr $74,733 Recycled Water Strategic Plan and City Staff
O&M Total ($/year)
O&M Subtotal $8,010,000 $9,208,713
($452,204)
$622,503
Subtractions --
--Additions
Calculated Total
O&M Cost Total ($/year)
$9,379,012
$9,380,000
19
Regional DPR
Regional DPR
Cost Estimate Summary Table (Palo Alto) (2)
Project
Cost Estimate Summary Table (Valley Water) (1)
Cost Units Project Cost Units
Total Capital Cost Total Capital Cost
Capital Cost $16,410,000
$0
$
$
Capital Cost $779,008,732
$0
$
$Land Acquisition Cost Land Acquisition Cost
Amortized Capital and Land Cost
Total O&M Cost
Amortized Capital and Land Cost
Total O&M Cost
$1,067,494 $ per Year $50,675,636 $ per Year
Groundwater Production Charge (GPC)$0 $ per Year
$ per Yr
O&M Cost $31,340,000 $ per Year
$ per Yr
O&M Cost (including Cost of Water)
Energy Cost (separate estimate, not added to
O&M)
$6,049,640 Total Unit Cost
$ per Yr Total Annual Cost$270,999 $82,015,636
24,000Total Unit Cost Project Yield
Unit Cost
AFY
Total Annual Cost $7,117,134
1,769
$ per AF
AFY
$3,417 $ per AF
1) This table calculates the estimated unit cost of the Regional DPR Facility with capital and O&M costs paid
by Valley WaterProject Yield
Capital Cost Unit Cost
GPC Unit Cost
$603
$0
$ per AF
$ per AF
$ per AF
$ per AF
$ per AF
O&M Unit Cost $3,420
$153
$4,024
Energy Unit Cost
Unit Cost (Including Cost of Water)
2) This table calculates the capital and O&M costs paid by Palo Alto for the pipeline from
the Regional DPR facility to Palo Alto's distribution system and adds the unit cost of that
pipeline to the unit cost of water from the Regional DPR Facility, reflecting what Palo Alto
would pay for this water on a unit basis.
Cost Escalation
Period
ENR Index (CoRe Plan, August 2019)
Current Cost Basis
ENR Date
Aug-1912,368
15,490 September 2023
20
Regional DPR
Yield Calculations
Yield Unit Source Notes
Yield Available to Palo Alto Flow available to Palo Alto based on 2022 flows to RWQCP; assumes no SSRF and all
partners send only 9 mgd to Regional FacilityFlow available for Local Reuse 0.88
1.0
mgd
mgd
mgd
(Palo Alto, 2023f)
Dewatering flow (W&C, 2019) TM 6.5, Section 8
Total flow available (influent)
Treatment Efficiency
Production Capacity (effluent)
Yield
1.88
84%
1.58
1,769
(B&C, 2021) Appendices, Appendix A-2, Section 2.1
mgd
afy
Total Regional Facility Yield
Regional Facility Yield 24,000 afy (B&C, 2021), Page 1
(Valley Water, 2023d)
Selected based on Valley Water's potable reuse goal of producing 24,000 afy by 2040.
Pulled from the Valley Water FAQs:
Energy Assumption
Energy Assumption 1.65 GWh/MGD
21
Regional DPR
Cost Escalation Method
Capital Cost (Valley Water)
Project Quantity Unit Unit Cost Original Cost Current Cost Source Notes
Adjustments
CoRe Plan DPR Options
CoRe Plan 1b: San Jose Raw Water
Augmentation (RWA) (Low)19,800 afy
afy
afy
afy
afy
$32,828
$27,083
$29,680
$23,125
$650,000,000
$650,000,000
$650,000,000
$555,000,000
(B&C, 2021), Table 6-13
(B&C, 2021), Table 6-13CoRe Plan 1b: San Jose RWA (High)
CoRe Plan 1b: San Jose RWA (average)
24,000
21,900
24,000
24,000
Note: Raw Water Augmentation is defined in (B&C, 2021) as
sending purified water into a pipeline system that delivers
untreated water to a drinking water treatment plant. Treated
Water Augmentation is defined in (B&C, 2021) as sending
purified water directly into the drinking water system.
CoRe Plan 1c: San Jose Treated Water
Augmentation (TWA), Milpitas Pipeline (B&C, 2021), Table 6-13
(B&C, 2021), Table 6-13CoRe Plan 1d: SJ TWA, new pipeline $25,208 $605,000,000
CoRe Plan DPR Average $26,005 $622,000,000 $779,008,732
Capital Cost Total (Rounded)--$779,008,732
O&M (Valley Water)
Project Quantity Unit Unit Cost Original Cost Current Cost Source Notes
Adjustments
CoRe Plan DPR Options
CoRe Plan 1b: San Jose RWA (Low)
CoRe Plan 1b: San Jose RWA (High)
19,800
24,000
21,900
afy
afy
afy
$1,237
$1,021
$1,119
$24,500,000
$24,500,000
$24,500,000
(B&C, 2021), Table 6-13
(B&C, 2021), Table 6-13
CoRe Plan 1b: San Jose RWA (average)
CoRe Plan 1c: San Jose TWA, Milpitas
Pipeline 24,000
24,000
afy
afy
$1,004
$1,004
$1,042
$0.10
$24,100,000
$24,100,000
$25,016,438
(B&C, 2021), Table 6-13
(B&C, 2021), Table 6-13CoRe Plan 1d: San Jose TWA, new pipeline
Escalated with ENR Index. No O&M cost provided in (B&C,
2021)
Not added to O&M, but estimated separately for the purposes
of energy cost tracking
CoRe Plan DPR Average 24,000 $31,331,228
Estimated Energy Cost 35,352,596 KWh $3,676,886 City Staff
O&M Cost Total (Rounded)--$31,340,000
22
Regional DPR
Capital Cost (Palo Alto)
Project Quantity Unit Unit Cost Original Cost Current Cost Source Notes
Treatment Facilities
n/a
Conveyance Length from Regional AWPF to Palo Alto Distribution System if
Regional AWPF located in Palo Alto on the former Los Altos
Treatment Plant sitePipeline Length 2 mi
ftPipeline (10")10,560
125%
$690 $7,286,400
$9,117,126
10" diameter estimated for expected flow and vmax = 5 fps
Construction Cost Markup
Storage
n/a
Pump Stations
n/a
Other
n/a
Calculated Total --
--
$16,403,526
$16,410,000Capital Cost Total (Rounded)
O&M Cost (Palo Alto)
Project Quantity Unit Unit Cost Original Cost Current Cost Source Notes
Treatment Facilities
n/a
Conveyance
Pipeline (10")0.5%of annual CAPEX $955,967 $4,780
Storage
n/a
Pump Stations
n/a
Other
n/a
Calculated Total
O&M Cost Total (Rounded)
--
--
$4,780
$4,800
23
DPR + SSRF
DPR with Small Salt Removal Facility (SSRF)
Cost Estimate Summary Table
Project Cost Units Keep or Remove SSRF Phase
Remove
1 Costs
Total Capital Cost
Capital Cost $48,900,000
$7,400,000
$3,662,396
$
$
< Select
Land Acquisition Cost
Amortized Capital and Land Cost
Total O&M Cost
Groundwater Production Charge
O&M Cost
$ per Year
$0 $ per Year
$ per Year
$ per Year
$1,897,644
$45,045Energy Cost
Total Unit Cost
Total Annual Cost
Project Yield
$5,605,085
630
$ per Yr
AFY
Capital Cost Unit Cost
GPC Unit Cost
$5,813
$0
$ per AF
$ per AF
$ per AF
$ per AF
$ per AF
O&M Unit Cost $3,012
$71Energy Unit Cost
Unit Cost $8,897
Cost Escalation
Period ENR Date
ENR Index (NW County RWSP, June 2018)
Current Cost Basis
12,015
15,490
June 2018
September 2023
Cost Escalation Method
Capital Costs
Project Quantity Unit Unit Cost Original Cost Current Cost Source Notes
Adjustments
Option D1 - Project Subtotal
Raw Construction Cost
Treatment - Original Capacity
Ozone
$43,006,000 (W&C, 2019), Option D1, pdf pg 134
4.73
4.73
4.73
4.73
MGD
MGD
MGD
MGD
$359,530
$317,232
$465,274
$274,934
$1,700,000
$1,500,000
$2,200,000
$1,300,000
--
--
--
--
(W&C, 2019), Option D1, pdf pg 134
(W&C, 2019), Option D1, pdf pg 134
(W&C, 2019), Option D1, pdf pg 134
(W&C, 2019), Option D1, pdf pg 134
BAC
Advanced Oxidation and Disinfection
Free Chlorine
Treatment - Reduced Capacities
Ozone
BAC
Back calculating from RO feed flow of 2.72 mgd. Assuming ~5%treatment loss through preceding MF/UF system and minimal
losses through the preceding Ozone or BAC system for an initial
feed flow of 2.85 mgd (2.72 mgd = 2.85 * ~95%)
2.85 MGD
MGD
$463,513
$408,982
--
--
$1,321,013
$1,165,600
(B&V, 2021), Table 5-12
(B&V, 2021), Table 5-122.85
1.6
Cost scaling factor applied to advanced oxidation/disinfection andfree chlorine processes to accommodate economy of scalelosses scaling from initial supply option D1. Assumed to be
similar cost factor used in the desalination supply option.
Cost Scaling Factor
--
Advanced Oxidation and Disinfection Assuming 25% of Phase 2 SSRF capacity allocated to Palo Alto
Assuming 25% of Phase 2 SSRF capacity allocated to Palo Alto
0.56
0.56
MGD
MGD
$599,841
$354,451
--
--
$548,292
$323,991Free Chlorine
Additional Capital Costs - Reduced Capacities
Remaining capital costs from include required infrastructure (size
adjusted): storage tanks, pump stations, mobilization, and trafficcontrol.Remaining Raw Capital Costs $17,534,400
--
--
Remaining Raw Capital Costs
Subtractions
0.50 multiplier $11,332,882
Treatment Facilities
MF/UF system 4.73
4.73
1.20
MGD
MGD
MGD
$6,200,000
$7,500,000
$1,900,000
RO System (W&C, 2019), Option D1, pdf pg 134 Included in SSRF costing below instead
RO Concentrate Treatment
Conveyance
Original HDPE Pipeline: 12 inch 5,000
500
lf
lf
lf
lf
$254
$334
$381
$462
$1,270,000
$167,000Original HDPE Pipeline: 20 inch
Original HDPE Pipeline: 24 inch
Original HDPE Pipeline: 30 inch
Storage
Original pipeline costs from (W&C, 2019) removed in orderto use updated pipeline costs(W&C, 2019), Option D1, pdf pg 1341,400
2,600
$533,400
$1,201,200
Pump Stations
Other
Additions
Treatment Facilities
Cost scaling factor applied to water stabilization and secondaryUV. Vendor quotes used for scaling include equipment only.Estimated adder accommodates installation and requiredstructural and mechanical work.
Cost Scaling Factor 2.0
--
Water Stabilization (Calcite Contactor)(Carollo, 2023a)Assuming 30% flow through calcite contactor, based on recentsimilar project estimates.0.17
0.56
MGD $920,000
N/A
$310,500
$175,200Addition of Secondary UV
Conveyance
(Carollo, 2023a)The Spektron 350 is appropriate for flow ranges from 0.4 to 0.7mgd, this cost was selected for the DPR + SSRF supply option.MGD N/A
Pipeline: 12 inch --
--
--
--
5,000
500
lf
lf
lf
lf
$740
$960
$3,700,000
$480,000Pipeline: 20 inch
Pipeline: 24 inch
Pipeline: 30 inch
Palo Alto project bids for Water MainReplacement 29 (June, 2023) and Water MainReplacement 27 (June, 2019) and extrapolationof trendline1,400 $1,010
$1,060
$1,414,000
2,6000.50 $2,756,000
$4,186,087Reduced Capacity MultiplierConveyance Total (Reduced Capacity)
Storage
Pump Stations
Other
Total Capital Cost
Raw Construction Cost
Construction Cost Markup
SSRF
$19,363,566
$47,410,5772.45 multiplier
Salt Removal Capital, Phase 1
Salt Removal Capital, Phase 2
Capital Cost Total
1.125
2.25
MGD
MGD
$0 (W&C, 2023), pg 4
$1,480,400
$48,900,000
City Staff Estimate
--
Land Cost
Original Capital Costs
Land required from DPR Dedicated
Project Size (DPR Dedicated)
50,000
57,315
4.22
sqft
sqft
$500
$200
$25,000,000 --(W&C, 2019), Option D1, pdf pg 134
MGD
Project Size (Based on MF/UF Treatment
Capacity)
Land scaled to size required for MF/UF component of SSRFfacility.2.72 MGD
sqft
(B&V, 2021) Table 5-12
Land required (scaled down)36,973 --
--
$7,394,592
Land Cost Total $7,400,000
24
DPR + SSRF
O&M Cost
Project Quantity Unit Unit Cost Original Cost Current Cost Source Notes
Option D1 - Original O&M
Total O&M $8,010,000 W&C, 2019, Option D1, pdf pg 134
Adjustments
Treatment - Original Project Capacity
Ozone 4.73
4.73
4.73
4.73
4.73
4.73
MGD
MGD
MGD
MGD
MGD
MGD
$93,055
$131,123
$338,381
$571,018
$74,021
$31,723
$440,000
$620,000
$1,600,000
$2,700,000
$350,000
$150,000
--
--
W&C, 2019, Option D1, pdf pg 134
W&C, 2019, Option D1, pdf pg 134
W&C, 2019, Option D1, pdf pg 135
W&C, 2019, Option D1, pdf pg 136
W&C, 2019, Option D1, pdf pg 134
W&C, 2019, Option D1, pdf pg 134
BAC
MF/UF System
RO System
Advanced Oxidation and Disinfection
Free Chlorine
--
--
Treatment - Reduced Project Capacity
Ozone Back calculating from RO feed flow of 2.72 mgd. Assuming ~5%
treatment loss through preceding MF/UF system and minimal
losses through the preceding Ozone or BAC system for an initialfeed flow of 2.85 mgd (2.72 mgd = 2.85 * ~95%)
2.85 MGD $119,968 --
--
$341,909
BAC
2.85
2.72
MGD
MGD
$169,046
$436,248
$481,781
$296,649
Advanced Water Purification System, (B&V, 2021),
Table 5-12
MF/UF System Based on RO feed flow rate. O&M for SSRF processes has beenscaled to 25% to match Palo Alto/Mountain View cost sharing.
Process capacity based Phase 2 gross production rate. O&M forSSRF processes has been scaled to 25% to match PaloAlto/Mountain View cost sharing.RO System
2.32
0.56
0.56
MGD
MGD
MGD
$736,168
$95,429
$40,898
$426,978
$53,440
$22,903
Advanced Oxidation and Disinfection --
--
Advanced Water Purification System, (B&V, 2021)Assuming 25% of Phase 2 SSRF capacity allocated to Palo AltoFree Chlorine
Resized and Escalated O&M Costs
Remaining O&M includes energy and consumables, and labor
associated with required infrastructure (conveyance piping,
storage tanks, pump stations).Remaining O&M Costs $1,762,218
--
--
Remaining O&M Costs
Subtractions
0.28 multiplier $488,267
Treatment Facilities
RO Concentrate treatment removed per direction of City,assuming RO Concentrate treatment not needed under current
discharge permit.
RO Concentrate Treatment 4.73 MGD ($280,000)($360,982)
($107,782)Original Energy Costs
Conveyance
718,547 KWh/yr $0.15 Input by City
Storage
Pump Stations
Other
Additions
Treatment Facilities
of annual CAPEX(not including landacquisition)
of annual CAPEX(not including landacquisition)
Estimated as 4% of annual capital cost. Operating costs forcalcite contactors include stabilization chemicals (calcite, sodiumhypochlorite) and a small amount of power.Calcite Contactor
Secondary UV
4%$3,181,015 $127,241
Estimated as 4% of annual capital cost. Operating costs forsecondary UV include power and lamp replacement.4%$3,181,015
$0.10
$127,241
$45,045Energy Costs
Total O&M Cost ($/year)
O&M Subtotal
Subtractions
433,098 KWh/yr City Staff Estimate
--
--
--
$2,111,927
($468,764)
$299,526Additions
Calculated Total $1,942,689$1,950,000O&M Cost Total ($/year)
25
IPR
Indirect Potable Reuse (IPR)
Cost Estimate Summary Table
Project Cost Units
Total Capital Cost
Capital Cost $188,900,000
$7,400,000
$
$Land Acquisition Cost
Amortized Capital and Land Cost
Total O&M Cost
$12,769,597 $ per Year
Groundwater Production Charge (GPC)
O&M Cost
$5,671,960
$6,213,260
$1,054,780
$ per Year
$ per Yr
Energy Cost $ per Yr
Total Unit Cost
Total Annual Cost
Project Yield
$25,709,597
5,150
$ per AF
AFY
Capital Cost Unit Cost
GPC Unit Cost
O&M Unit Cost
Energy Unit Cost
Unit Cost
$2,480
$1,101
$1,206
$205
$ per AF
$ per AF
$ per AF
$ per AF
$ per AF$4,992
Cost Escalation
Period ENR Date
ENR Index (NW County RWSP, June 2018)
Current Cost Basis
12,015
15,490
June 2018
September 2023
Cost Escalation Method
Capital Costs
Project Quantity Unit Unit Cost Original Cost Current Cost Source NotesCapital Cost
Original Capital Cost $70,700,000 $91,147,982 W&C, 2019, Option C1, pdf pg 128 Total capital cost ($92.2M) minus land acquisition ($21.5M), escalated to 2023
Adjustments (Land Acquisition only)Land AcquisitionOriginal Land Acquisition
Treatment Facility Land Cost
Rinconada Land Cost
20,000
9,000
sq ft
sq ft
sq ft
$500
$500
$500
$10,000,000
$4,500,000
$7,000,000
W&C, 2019, Option C1, pdf pg 128
W&C, 2019, Option C1, pdf pg 128
W&C, 2019, Option C1, pdf pg 128
Cost provided in RWSP as lump sum
Cost provided in RWSP as lump sumPeers Land Cost 14,000
Revised Land Acquisition
Treatment Facility Land Cost
El Camino Park Well (Qmax = 1,850 gpm)
Eleanor Pardee Park Well (Qmax =1000 gpm)
Rinconada Land Cost
23,000
0
sq ft
sq ft
sq ft
sq ft
sq ft
$200
$200
$200
$200
$200
4,600,000 City Staff Estimate
City Staff Estimate$0
$0
There is sufficient land for Manganese (Mn), Iron (Fe), and Total Dissolved Solids (TDS) treatment at this site
There is sufficient land for Manganese (Mn), Iron (Fe), and Total Dissolved Solids (TDS) treatment at this site
Not included in OWP since 3 wells are sufficient to produce expected yield
0 City Staff Estimate
9,000
14,000
Area calculated from Cost in W&C, 2019
Area calculated from Cost in W&C, 2019Peers Well (Qmax =1700 gpm)
Adjustments (Treatment only)
Treatment Facilities
$2,800,000 Updated land cost based on $200/sft instead of $500/sft.
Wellhead Treatment at El Camino Well 1,000
1,000
1,700
0
gpm
gpm
gpm
gpm
gpm
gpm
$
$
$
$
$
$
-
-
-
-
-
-
$
$
$
9,297,460 Assumes treatment for Fe, Mn and TDS (Carollo, 2000, Option #4)
Assumes treatment for Fe, Mn and TDS (Carollo, 2000, Option #4)
Assumes treatment for Fe, Mn and TDS (Carollo, 2000, Option #4)
Not included in OWP since 3 wells are sufficient to produce expected yield
Not included in OWP since 3 wells are sufficient to produce expected yield
Not included in OWP since 3 wells are sufficient to produce expected yield
(Carollo, 2000) and (Todd Groundwater,2018)Wellhead Treatment at Eleanor Pardee Well
Wellhead Treatment at Peers Park Well
Wellhead Treatment at Hale Park Well
Wellhead Treatment at Rinconada Park Well
9,297,460
11,675,879
(Carollo, 2000) and (Todd Groundwater,2018)0
Wellhead Treatment at Library Park Well
Total Adjustment
0 $30,270,798
Subtractions
Treatment Facilities
n/a
Conveyance
Original HDPE Pipeline: 8 inch 2,000
1,500
5,000
20,500
0.870
lf $200
$212
$254
$277
$400,000
$318,000
($515,689)
Original HDPE Pipeline: 10 inch
Original HDPE Pipeline: 12 inch
Original HDPE Pipeline: 16 inch
Construction Cost Markup
lf ($409,973)
($1,637,312)
($7,320,846)
($8,598,923)
Original pipeline costs from W&C, 2019 removed in order to use updated pipeline costs
W&C, 2019 multiplier used to remove RW&C, 2019-based cost
lf
lf
$1,270,000
$5,678,500
$6,669,855
W&C, 2019 Option C1, pdf pg 128
multiplier
Storage
n/a
Pump Stations
n/a
Other
n/aAdditions
Conveyance (RO waste stream/brine)Brine line flowrate assumption (RO and Fe/Mn)25%
250
of Q_well
Brine line flowrate El Camino Well
Brine line flowrate Eleanor Pardee Park Well
Brine line flowrate Peers Park Well
Brine line flowrate Hale Park Well
gpm requires a 4.5
4.5
6.0
inch diameter brine line
250 gpm requires a
requires a
inch diameter brine line; and 8" once combined with brine from El Camino Well and Peers Well
inch diameter brine line; and 6" once combined with brine from El Camino Well425gpm
0 gpm Not included in OWP since 3 wells are sufficient to produce expected yield
Brine line flowrate Rinconada Park Well
Brine line flowrate Library Park Well
Brine line flowrate (all 6 wells)
0 gpm Not included in OWP since 3 wells are sufficient to produce expected yield
Not included in OWP since 3 wells are sufficient to produce expected yield0gpm
925 gpm
Design velocity 5 ft/sec
Brine line from El Camino and Peers Well to junction (6 inch)
Brine Line from El Camino & Peers Wells to Eleanor Well (6 inch)
Brine Line from Elenaor Well to RWQCP (8 inch)
Brine Line from El Camino Well to Sewer (6 inch)
Brine Line from Peers Well to Sewer (6 inch)
Brine Line from Eleanor Well to Sewer (6 inch)
Brine Line from Hale Well to Sewer (6 inch)
Brine Line from Rinconada Well to Sewer (6 inch)
Brine Line from Library Well to Sewer (6 inch)
Pipeline: 8 inch
7,500
6,400
10,600
1,500
100
lf $560 --
--
$9,455,261
$8,068,489
$14,795,231
lf $560
$620
$560
$560
$560
$560
$560
$560
$620
$690
$740
$850
lf --
--lf Discharge to sewer replaced with dedicated brine line.
lf --
--
--
--
--
Discharge to sewer replaced with dedicated brine line.
830 lf Discharge to sewer replaced with dedicated brine line.
100 lf Not included in OWP since 3 wells are sufficient to produce expected yield
Not included in OWP since 3 wells are sufficient to produce expected yield
Not included in OWP since 3 wells are sufficient to produce expected yield
100 lf
100 lf
2,000
1,500
5,000
20,500
1.251
lf --
--
--
--
$1,240,000
$1,035,000
$3,700,000
$17,425,000
$29,279,309
Pipeline: 10 inch lf W&C, 2019 Option C1, pdf pg 128Pipeline: 12 inch lf
lfPipeline: 16 inch
Pipeline Construction Cost Markup multiplier
StorageOptions 4: Backwash water storage for Fe & Mn treatment (3 sites)
Backwash volume 5 times Q_well
mins/cycle
time per day
MG
Backwash duration
Backwash frequency
15
1
Backwash volume El Camino Well @ 1000 gpm
Backwash volume Eleanor Pardee Well @ 1000 gpm
Backwash volume Peers Well @ 1700 gpm
Backwash volume Hale Well @ 609 gpm
Backwash volume Rinconada Well @ 609 gpm
Backwash volume Library Well @ 609 gpm
Connection to sewer EC/EP/P well
Pump Stations (Option 4 only)
0.08
0.08
0.13
0.00
0.00
0.00
4
$1.00
$1.00
$1.00
$1.00
$1.00
$1.00
100
n/a
n/a
n/a
n/a
n/a
n/a
$
$
$
168,844
MG 168,844
287,035MG
MG Not included in OWP since 3 wells are sufficient to produce expected yield
Not included in OWP since 3 wells are sufficient to produce expected yield
Not included in OWP since 3 wells are sufficient to produce expected yield
MG
MG
inches feet $117,065 ######################################## gpm on average
Brine PS at El Camino Well @ 250 gpm
Brine PS at Eleanor Well @ 250 gpm
Brine PS at Peers Well @ 425 gpm
Construction Cost Markup
2
2
hp
hp
20
20
20
feet TDH
feet TDH
feet TDH
$
$
$
$
40,648
40,648
69,102
188,186
Assumes pressurized flow of brine to RWQCP outfall
Assumes pressurized flow of brine to RWQCP outfall
Assumes pressurized flow of brine to RWQCP outfall3hp
1.251 multiplier
Other
n/a
Sewer Connection Charge El Camino Well
Sewer Connection Charge Eleanor Pardee Park Well
Sewer Connection Charge Peers Park Well
Sewer Connection Charge Hale Park Well
Sewer Connection Charge Rinconada Park Well
1
1
1
1
1
1
connection
connection
connection
connection
connection
connection
9,846
9,846
9,846
9,846
9,846
9,846
9,846
9,846
9,846
WASTEWATER SERVICE CONNECTION CHARGES UTILITY RATE SCHEDULE S-5
WASTEWATER SERVICE CONNECTION CHARGES UTILITY RATE SCHEDULE S-6
WASTEWATER SERVICE CONNECTION CHARGES UTILITY RATE SCHEDULE S-7
Not included in OWP since 3 wells are sufficient to produce expected yield
Not included in OWP since 3 wells are sufficient to produce expected yield
Not included in OWP since 3 wells are sufficient to produce expected yieldSewer Connection Charge Library Park Well
Total Capital Cost
Capital Cost $70,700,000
$21,500,000
$92,200,000
$91,147,982
Land Acquisition $7,400,000
Original Total $98,547,982
Adjustments (treatment)
Subtractions
$
$
30,270,798
--
--
--
--
($18,482,741)
85,961,595
$196,297,634
#####
Additions
Calculated Total
Capital Cost Total (Rounded)
26
IPR
O&M Cost
Project Quantity Unit Unit Cost Original Cost Current Cost Source Notes
AdjustmentsO&M Cost
Original Annual O&M $14,820,000 W&C, 2019, Option C1, pdf pg 129
W&C, 2019, Option C1, pdf pg 129Groundwater Production Charges (RWSP)5,900 afy $1,960 ($11,564,000)
$3,256,000Original Annual O&M without GW Prodcution Charge $4,197,706
$5,671,960
Per discussions with VW, it is reasonable to assume that there may be some losses associated with recharge water,
so the GPC may apply to a portion of the volume associated with recharge. Assuming 10% per similar recharge
assumptions in other California projects.
Groundwater Product Charge Recharge Loss Assumption 10%
Pumping charge should only be applied to GW pumping amount (3,000 afy), not recharge amount (5,900 afy)Groundwater Production Charges (Adjusted)3,290 afy $1,724
Subtractions
Treatmentn/a
Conveyance Pipelines
n/aPump Station(s)n/a
Storage
n/a
Other
Original Energy Cost 342,958 KWh/yr $0.15 $51,444 $66,322
Additions
Treatment (Fe/Mn and Ammonia)
Wellhead Treatment: El Camino Well
Wellhead Treatment: Pardee Park Well
Wellhead Treatment: Peers Park Well
Wellhead Treatment: Hale Park Well
Wellhead Treatment: Rinconada Park Well
Wellhead Treatment: Library Park Well
SFPUC water for backwash of Wellhead Treatment: El Camino Well
SFPUC water for backwash of Wellhead Treatment: Pardee Park We
SFPUC water for backwash of Wellhead Treatment: Peers Park Well
RO Treatment: El Camino Well
1,000
1,000
1,700
0
gpm
gpm
gpm
gpm
gpm
gpm
afy
$
$
$
46,947
46,947
50,539 Included in Carollo 2000, but not in Todd
Groundwater, 2018
Not included in OWP since 3 wells are sufficient to produce expected yield
Not included in OWP since 3 wells are sufficient to produce expected yield
Not included in OWP since 3 wells are sufficient to produce expected yield
0
0
84 $2,069
$2,069
$2,069
$/AF
$/AF
$/AF
$
$
$
$
$
$
173,822
173,822
295,497
380,378
380,378
596,369
84 afy
143
1,000
1,000
1,700
afy
gpm
gpm
gpm
RO Treatment: Pardee Park Well
RO Treatment: Peers Park Well
Conveyance Pipelines
n/a
Pump Station(s)
n/a
Storage
n/a
Other
Energy Cost for Groundwater pumping El Camino Well
Energy Cost for Groundwater pumping Eleanor Pardee Park Well
Energy Cost for Groundwater pumping Peers Park Well
Energy Cost for Groundwater pumping Hale Park Well
Energy Cost for Groundwater pumping Rinconada Park Well
Energy Cost for Groundwater pumping Library Park Well
Energy Cost for RO treatment for El Camino Well
Energy Cost for RO treatment for Eleanor Pardee Park Well
Energy Cost for RO treatment for Peers Park Well
204
280
850
828
900
285
ft
ft
ft
ft
ft
ft
1,000 gpm
gpm
gpm
gpm
gpm
gpm
$50,019 Todd Groundwater, Table 4-2
Todd Groundwater, Table 4-2
Todd Groundwater, Table 4-2
1,000 $68,654
1,700 $354,304 Scaled Peers Well production to not exceed 5900 afy = 3700 gpm)
Not included in OWP since 3 wells are sufficient to produce expected yield
Not included in OWP since 3 wells are sufficient to produce expected yield
Not included in OWP since 3 wells are sufficient to produce expected yield
-
-
(3,700)
$138,705
$138,705
$238,069
Sewer Service Charge for 3 wells Brine
Sewer Service Charge for 3 wells Backwash
Sewer Capacity Charge
O&M Total ($/year)
64,984,401
13,540,169
ft^3
ft^3
9.08
9.08
$/hcf
$/hcf
5,900,584 COMMERCIAL WASTEWATER COLLECTION AND DISPOSAL UTILITY RATE SCHEDULE S-2
1,229,447 COMMERCIAL WASTEWATER COLLECTION AND DISPOSAL UTILITY RATE SCHEDULE S-3
1
Original Total $14,820,000 $9,869,666
($66,322)
3,133,156
Subtractions --
--
--
Additions
Calculated Total $12,936,500
$12,940,000Total O&M Cost ($/year, Rounded)
27
NPR
Non Potable Reuse (NPR)
Cost Estimate Summary Table
Project Cost Units
Total Capital Cost
Capital Cost $148,510,000
$0
$
$Land Acquisition Cost
Amortized Capital and Land Cost
Total O&M Cost
Groundwater Production Charge
O&M Cost
$9,660,789 $ per Year
$0 $ per Year
$ per Year
$ per Year
$909,679
$82,592Energy Cost
Total Unit Cost
Total Annual Cost
Project Yield
$10,570,467
1,100
$8,783
$0
$ per Yr
AFY
Capital Cost Unit Cost
GPC Unit Cost
$ per AF
$ per AF
$ per AF
$ per AF
$ per AF
O&M Unit Cost $827
Energy Unit Cost
Unit Cost
$75
$9,610
Cost Escalation
Period ENR Date
ENR Index (NW County RWSP, June 2018)
Current Cost Basis
12,015
15,490
June 2018
September 2023
Cost Escalation Method
Capital Costs
Project Quantity Unit Unit Cost Original Cost Current Cost Source Notes
Adjustments
Capital Cost
Original Capital Cost
Subtractions
Treatment Facilities
n/a
$63,000,000 $81,220,974 W&C, 2019, Option A2, pdf pg 116
Conveyance
Original HDPE Pipeline: 8 inch 50,383
8,600
5,500
1,000
7,115
lf
lf
lf
lf
lf
$200
$212
$254
$277
$334
$10,076,600
$1,823,200
$1,397,000
$277,000
($12,990,972)
($2,350,509)
($1,801,043)
($357,114)
Original HDPE Pipeline: 10 inch
Original HDPE Pipeline: 12 inch
Original HDPE Pipeline: 16 inch
Original HDPE Pipeline: 20 inch
Original pipeline costs from W&C, 2019 removed in
order to use updated pipeline costsW&C, 2019, Option A2, pdf pg 116
$2,376,410 ($3,063,720)W&C, 2019, multiplier used to remove W&C, 2019,-based costConstruction Cost Markup $11,809,206 ($15,224,686)0.870 multiplier
Storage
n/a
Pump Stations
n/a
Other
n/a
Additions
Treatment Facilities
SSRF Phase 1 costs removed as MV agreed to paythe remaining capital costs.Small Salt Removal Capital, Phase 1
Salt Removal Capital, Phase 2
$0 W&C, 2023, pg 4
City Staff Estimate$1,480,400
Conveyance
Pipeline: 8 inch
Pipeline: 10 inch
Pipeline: 12 inch
Pipeline: 16 inch
Pipeline: 20 inch
50,383
8,600
5,500
1,000
7,115
1.251
lf $620
$690
$740
$850
$960
$31,237,460
$5,934,000
$4,070,000
$850,000
lf
lf W&C, 2019, Option A2, pdf pg 116lf
lf $6,830,400
$52,667,045Construction Cost Markup multiplier
Storage
n/a
Pump Stations
n/a
OtherEnergy CostTotal Capital Cost
Original Total $63,000,000 $81,220,974
($35,788,044)
$103,069,305
$148,502,234
$148,510,000
Subtractions
Additions
--
--
--
--
Calculated Total
Capital Cost Total (Rounded)
28
NPR
O&M Cost
Project Quantity Unit Unit Cost Original Cost Current Cost Source NotesAdjustments
O&M Cost
Original Annual O&M $520,000 $670,395 W&C, 2019, Option A2, pdf pg 117
Subtractions
Treatment
n/a
Conveyance Pipelines
n/a
Pump Station(s)
n/a
Storagen/a
Other
Original Energy Cost 794,111 KWh/yr $0.15 ($119,117)Input by City
Additions
Treatment
n/a
Conveyance Pipelines
n/a
Pump Station(s)
n/a
Storage
n/a
Other
SSRF O&M 1,100
0.56
afy
MGD Calculated average O&M cost per mgd from enhancedrecycled water demand scenarios included in (W&C,
2023) and increased to the yield for this supply option.$640,000 per MGD
KWh/yr
$358,400
$82,592
W&C, 2023, Section 4.2
Energy Cost
O&M Total ($/year)
Original Total
794,111 $0.10
$520,000 $670,395
($119,117)
$440,992
$992,271
$1,000,000
Subtractions --
--
--
Additions
Calculated Total
Total O&M Cost ($/year, Rounded)
29
Desalination
Desalination
Cost Estimate Summary Table
Project Cost Units
Total Capital Cost
Capital Cost $251,832,599
$43,560,000
$19,215,712
$
$Land Acquisition Cost
Amortized Capital and Land Cost
Total O&M Cost
Groundwater Production Charge
O&M Cost
$ per Year
$0 $ per Year
$ per Year
$ per Year
$9,827,073
$1,281,486Energy Cost
Total Unit Cost
Total Annual Cost
Project Yield
$30,324,272
4,480
$ per Yr
AFY
Capital Cost Unit Cost
GPC Unit Cost
$4,289
$0
$ per AF
$ per AF
$ per AF
$ per AF
$ per AF
O&M Unit Cost $2,193
$286Energy Unit Cost
Unit Cost $6,768
Cost Escalation
Period ENR Date
Feb-15ENR Index (BAWSCA Long Term Regional Water Strateg
Current Cost Basis
11,178
15,490 September 2023
Cost Escalation Method
Capital Costs
Project Quantity Unit Unit Cost Original Cost Current Cost Source Notes
Adjustments
Capital Cost Escalation
BAWSCA 15 mgd Open Bay Intake - Low
BAWSCA 15 mgd Open Bay Intake - High
BAWSCA 15 mgd Open Bay Intake - Average
15 mgd Open Bay Intake - Escalated
Adjustment for Change in Size
5 mgd Open Bay Intake
15
15
15
15
MGD
MGD
MGD
MGD
$20,600,000
$24,133,333
$22,366,667
$30,994,781
$309,000,000
$362,000,000
$335,500,000
Cost estimate from BAWSCA study includes intake,
treatment, and conveyance and does not include
land acquisition or brine disposal.CDM Smith, 2015, Table B-10
$464,921,721
$154,973,907
15 mgd facility escalated to 2023 cost
5 MGD $30,994,781
1.6
No loss of economies of scaleSee Additional Calculations for scaling factor to
account for loss of economies of scale for smaller
facility.Cost Scaling Factor (15 -> 5 mgd)
BAWSCA 15 mgd Open Bay Intake - Average
Land Acquisition
$251,832,599
$43,560,000
Capital Cost including loss of economies of scale
CDM Smith, 2015, Section B.3 1 acre/mgd of treated water capacityLand Acquisition
Land Acquisition
5 ac
sq ft217,800 $200
Total Capital Cost
Capital Cost $251,832,599
$43,560,000
$295,392,599
$295,400,000
Land Acquisition
Calculated Total
Capital Cost Total (Rounded)
30
Desalination
O&M Cost
Project Quantity
73%
5
Unit Unit Cost
$16,382,072
$437,000
Original Cost Current Cost Source Notes
Adjustments
O&M Cost $12,012,073 See Reference CalculationsO&M Total calculation
Subtractions
of annual CAPEX
MGD Estimated from Table A9-B of the
BAWSCA_Volume_II_Phase_II_A_AttachmentsEnergy Cost ($2,185,000)City Staff Estimate
City Staff Estimate
Additions Estimated energy required from Valley Water
Recycled Water Committee presentation, From
Watts to Water, May 2011Energy Cost KWh/AF2750.00 $0.104006 $1,281,486
$12,012,073
($2,185,000)
$1,281,486
$11,108,559
$11,110,000
Original Total
Subtractions
Additions
--
--
--Calculated Total
Total O&M Cost ($/year, Rounded)
Reference Calculations for Estimating Capital and O&M Costs
Assumptions 15 mgd Open Bay Intake - Low Source$309,000,000
3.5%
CDM Smith, 2015, Table B-10Capital Cost
Interest Rate in 2015
Amortized Capital Cost
O&M annual
$16,800,741
$13,200,000
$30,000,741
79%
CDM Smith, 2015, Table B-10
Total Annual Cost
O&M % of Annual CAPEX
Assumptions 15 mgd Open Bay Intake - High
Capital Cost $362,000,000
3.5%
CDM Smith, 2015, Table B-10
CDM Smith, 2015, Table B-10
Interest Rate in 2015
Amortized Capital Cost
O&M annual
$19,682,422
$13,400,000
$33,082,422
68%
Total Annual Cost
O&M % of Annual CAPEX
31
Multi Source Storage
Multi Source Storage
Cost Estimate Summary Table
Project Cost Units
Total Capital Cost
Capital Cost $22,630,000
$0
$
$Land Acquisition Cost
Amortized Capital and Land Cost
Total O&M Cost
Groundwater Production Charge
O&M Cost
$1,472,114 $ per Year
$0
$60,000
$0
$ per Year
$ per Year
$ per YearEnergy Cost
Total Unit Cost
Total Annual Cost
Project Yield
$1,532,114
39
$ per Yr
AFY
Capital Cost Unit Cost
GPC Unit Cost
$38,125
$0
$ per AF
$ per AF
$ per AF
$ per AF
$ per AF
O&M Unit Cost $1,554
$0Energy Unit Cost
Unit Cost $39,679
Bottom Up Calculation
Capital Costs
Project Quantity Unit Unit Cost Cost Estimate Source Notes
Treatment Facilities
Peers Park, Dewatering Oregon Expressway
Ramos Park, RW Connection
Hoover Park, Oregon Expwy Dewatering
Johnson Park, City Hall Dewatering
Heritage Park, City Hall Dewatering
0.068
0.045
0.063
0.040
0.028
MGD
MGD
MGD
MGD
MGD
$4.50
$4.50
$4.50
$4.50
$4.50
$307,506
$202,809
$285,316
$179,678
$125,504
Using PHD/ADD peaking factor of 6.0
Conveyance
4-Inch Diameter Pipeline
Peers Park, Dewatering Oregon Expressway
Ramos Park, RW Connection
Hoover Park, Oregon Expwy Dewatering
Johnson Park, City Hall Dewatering
Heritage Park, City Hall Dewatering
3,000
4,000
4,000
3,000
1,500
LF
LF
LF
LF
LF
$520
$520
$520
$520
$520
$1,560,000
$2,080,000
$2,080,000
$1,560,000
$780,000
Storage
Peers Park, Dewatering Oregon Expressway
Ramos Park, RW Connection
Hoover Park, Oregon Expwy Dewatering
Johnson Park, City Hall Dewatering
Heritage Park, City Hall Dewatering
12,000
8,000
11,000
7,000
5,000
gallons
gallons
gallons
gallons
gallons
$14
$14
$14
$14
$14
$170,000
$120,000
$160,000
$100,000
$70,000
Pump Stations
Supply PS Construction Cost (from Stormwater/Dewatering Site to Park)
Peers Park, Dewatering Oregon Expres
Ramos Park, RW Connection
1
1
1
1
1
hp
hp
hp
hp
hp
$10,000
$10,000
$10,000
$10,000
$10,000
$10,000
$10,000
$10,000
$10,000
$10,000
Hoover Park, Oregon Expwy Dewaterin
Johnson Park, City Hall Dewatering
Heritage Park, City Hall Dewatering
Irrigation PS Construction Costs (from below-ground storage to feed irrigation system)
Peers Park, Dewatering Oregon Expres
Ramos Park, RW Connection
3
2
3
2
2
hp
hp
hp
hp
hp
$10,000
$10,000
$10,000
$10,000
$10,000
$30,000
$20,000
$30,000
$20,000
$20,000
Hoover Park, Oregon Expwy Dewaterin
Johnson Park, City Hall Dewatering
Heritage Park, City Hall Dewatering
Other Report to be prepared by City, estimates per City
staffTitle 22 Report 5 EA $20,000 $100,000
Land Acquisition Cost
Total Capital Cost Assumption Cost
Peers Park, Dewatering Oregon Expressway $2,097,506
Ramos Park, RW Connection
Hoover Park, Oregon Expwy Dewatering
Johnson Park, City Hall Dewatering
Heritage Park, City Hall Dewatering
Total Raw Construction Cost (2023 $)
Peers Park, Dewatering Oregon Expressway
Ramos Park, RW Connection
$2,452,809
$2,585,316
$1,889,678
$1,025,504
$10,050,814
$4,722,016
$5,521,893
$5,820,200
$4,254,143
$2,308,668
$22,626,920
Hoover Park, Oregon Expwy Dewatering
Johnson Park, City Hall Dewatering
Heritage Park, City Hall Dewatering
Construction Cost Multiplier 2.25
Capital Cost Total (Rounded)$22,630,000
32
Multi Source Storage
O&M Cost
Project Quantity Unit Unit Cost Cost Estimate
$6,448
Source Notes
Treatment
Capital Cost for Treatment only $2,478,210
$161,211Annualized Capital Cost for Treatment only
Annual O&M 4%
Conveyance Pipelines
Capital Cost for Pipelines only
Annualized Capital Cost for Treatment only
Annual O&M
$18,145,095
$1,057,463
0.5%
2.0%
$5,287
Pump Station(s)
Capital Cost for PS only
Annualized Capital Cost for PS only
Annual O&M
$382,713
$30,710
$614
Storage
Capital Cost for Storage only
Annualized Capital Cost for Storage only
Annual O&M
$1,395,777
$112,001
1.0%$1,120
Land
n/a
Other
O&M Staff (inspections per site)
Number of sites
96
5
hrs/yr per site
$/hourLabor Cost (salary + benefits)$80 $38,538
O&M Total
Calculated O&M Total
Total O&M Cost ($/year, Rounded)
$52,008
$60,000
33
Green Infrastructure
Green Infrastructure
Cost Estimate Summary Table
Project Cost Units
Total Capital Cost
Capital Cost $4,080,000
$0
$
$Land Acquisition Cost
Amortized Capital and Land Cost
Total O&M Cost
Groundwater Production Charge
O&M Cost
$265,410 $ per Year
$0
$240,000
$0
$ per Year
$ per Year
$ per YearEnergy Cost
Total Unit Cost
Total Annual Cost
Project Yield
$505,410
30
$ per Yr
AFY
Capital Cost Unit Cost
GPC Unit Cost
$8,847
$0
$ per AF
$ per AF
$ per AF
$ per AF
$ per AF
O&M Unit Cost $8,000
$0Energy Unit Cost
Unit Cost $16,847
Cost Escalation
Period ENR
11,155
1.14
Date
Jul-16One Water LA 2040 Plan (Final, April 2018)
RS Means Adjustment SoCal to SF Bay Area
Current Cost Basis
Jul-05
15,490 September 2023
Cost Escalation Method
Capital Costs
Project Quantity Unit Unit Cost Original Cost Current Cost Source Notes
Cost Estimating Basis
One Water LA : Green Streets Option 1 length
One Water LA : Green Streets Option 1 yield
One Water LA : Green Streets Option 1 Capital Cost
One Water LA : Green Streets Option 1 unit cost
Capital Cost per mile (calculated)
Adjustments
1,690 miles
afy11,900 Carollo, 2018a, Volume 5. TM5.2 - Appendix Normal Year hydrology
$M $875 $1,379
$11,821
$0.82
C, Concept Option #1 Average of high and low cost estimates
$/AF
$M/mile
$7,500
$0.52
Palo Alto Project Sizing Estimated by approximating the miles of high and medium priority streets projects in
the figureGreen Street length
Yield
Palo Alto, 2019a, Figure 4.15miles
Note that infiltration may not necessarily lead to increased groundwater availability, so
the yield for this project may actually be 0.Assumes linear cost relation (marginal economies of scale)
30 afy
Capital Cost $/mile $816,000 $4,080,000
Subtractions
Treatment Facilities
n/a
Conveyance
n/a
Storage
n/a
Pump Stations
n/a
Other
n/a
Additions
Treatment Facilities
n/a
Conveyance
n/a
Storage
n/a
Pump Stations
n/a
Other
n/a
Total Capital Cost
Capital Cost
Land Acquisition
Original Total
Subtractions
Additions
$4,080,000
$0 n/a (green streets are assumed to be constructed in public Right of Way)$4,080,000
$0--
--$0
Calculated Total
Capital Cost Total (Rounded)
$4,080,000
$4,080,000--
34
Green Infrastructure
O&M Cost
Project Quantity Unit Unit Cost Original Cost Current Cost Source
Cost Estimating Basis
Carollo, 2018a, Volume 5, TM5.2 - AppendixD, Concept Option #1One Water LA : Green Streets Option 1 O&M $/year $50,970,535
$30,200
$80,337,970
$47,500
One Water LA : Green Streets Option 1 length
O&M Cost per mile (calculated)
Adjustments
1,690 miles
$/mile per year
Palo Alto Project Sizing
Palo Alto, 2019a, Figure 4.1 Estimated by approximating the miles of high and medium priority streets projects in
the figureGreen Street length 5 miles
O&M Cost $/mile $47,500 $237,500
Subtractions
Treatment Facilities
n/a
Conveyance
n/a
Storage
n/a
Pump Stations
n/a
Other
n/a
Additions
Treatment Facilities
n/a
Conveyance
n/a
Storage
n/a
Pump Stations
n/a
Other
n/a
O&M Total ($/year)
O&M Cost $237,500
$0Subtractions
Additions
--
--$0
Calculated Total
Capital Cost Total (Rounded)
$237,500
$240,000--
35
Graywater
Graywater
Cost Estimate Summary Table
Project Cost Units
Total Capital Cost
Capital Cost $0
$0
$0
$
$Land Acquisition Cost
Amortized Capital and Land Cost
Total O&M Cost
Groundwater Production Charge
O&M Cost
$ per Year
$0
$46,650
$0
$ per Year
$ per Year
$ per YearEnergy Cost
Total Unit Cost
Total Annual Cost
Project Yield
$46,650
5.7
$ per Yr
AFY
Capital Cost Unit Cost
GPC Unit Cost
$0 $ per AF
$ per AF
$ per AF
$ per AF
$ per AF
$0
O&M Unit Cost $8,215
$0Energy Unit Cost
Unit Cost $8,215
Programmatic Cost Estimate
Project Costs Project Yield and Cost
Year
Project Assumptions Units Cost Source Notes
General Assumptions
Staff Time Single Family Facilities City Facilities Single Family + City Facilities0.25 FTE Assuming 0.25 FTE per City input
Staffing Cost - Salary and Benefits
Annual Staffing Cost
Calculations
$167,000 $/FTE
$41,750 CY Count Yield Install Cost Yield Install Cost Total Yield Total Cost
2024 1 0.44 $1,718 0.10 $10,000 0.54 $53,468
1) Single Family Facilities
Saving Assumptions
Single Family Accts (2040)
2025
2026
2
3
0.88
1.32
$1,718
$1,718
0.20
0.31
$10,000
$10,000
1.08
1.63
$53,468
$53,46822years
accts
Based on savings in 2045
18,869 (Palo Alto, 2021, Table 11)
(Valley Water, 2023e)
Single family account projections in 2045
Assuming 1% adoption from UWMP 2045 projection
2027 4 1.76 $1,718 0.41 $10,000 2.17 $53,468
Graywater Adoption Rate
Annual Single Family Facilities
Cost for Single Family Install
1%
9
$200
rate
device/yr
$/system
2028
2029
2030
5
6
7
2.20
2.64
3.08
$1,718
$1,718
$1,718
0.51
0.61
0.72
$10,000
$10,000
$10,000
2.71
3.25
3.80
$53,468
$53,468
$53,468Palo Alto's portion of the graywater rebate program.Average number of persons per home in Palo Alto per
US Census dataPersons/Household 2.62 PPH US Census Bureau 2031 8 3.52 $1,718 0.72 $0 4.24 $43,468SFPUC manual assumes 15 gpd per person of
graywater generation from laundry systems onlyGPD per person of graywater
Graywater/Household
SFPUC, 2018, pdf pg. 1915
39
gpd
gpd
2032
2033
9 3.96
4.40
$1,718
$1,718
0.72
0.72
$0
$0
4.68
5.12
$43,468
$43,46810
Total Water Captured per Year (SFfacilities)
Savings in 2024
0.44 AFY
AFY
AFY
AF
2034
2035
2036
2037
11
12
13
14
4.84
5.28
5.72
6.16
$1,718
$1,718
$1,718
$1,718
0.72
0.72
0.72
0.72
$0
$0
$0
$0
5.56
6.00
6.44
6.88
$43,468
$43,468
$43,468
$43,468
0.44
9.7Savings in 2045
Total Savings 111.3
2) City Facilities 2038
20392040
15
1617
6.60
7.047.48
$1,718
$1,718$1,718
0.72
0.720.72
$0
$0$0
7.32
7.768.20
$43,468
$43,468$43,468Saving Assumptions
Total City Facilities
77 yearssites Assuming one city facility installed per year
6 fire stations, 1 community poolAssuming 2x single family household yield per CityfacilityGraywater/City facility 79 gpd
sites
2041
2042
2043
18
19
20
7.92
8.36
8.80
$1,718
$1,718
$1,718
0.72
0.72
0.72
$0
$0
$0
8.64
9.08
9.52
$43,468
$43,468
$43,468
Annual City Facilities 1.00
Cost for City Site Install $10,000 $/system
Total Water Captured per Year (Cityfacilities)
Savings in 2024
0.72 AFY
AFY
AFY
AF
2044
2045
21
22
9.24
9.68
$1,718
$1,718
$37,800
0.72
0.72
13.6
$0
$0
9.96
10.40
124.9
$43,468
$43,4680.10
0.72
13.6
Savings in 2045
Total Savings
Total (through 2045)111.3 $70,000 $1,026,300
Total Costs
Total Annual Program Costs
Lifetime Costs
$46,650
$1,026,300
$8,215Unit Cost ($/AF)
36
Rain Barrels
Rain Barrels
Cost Estimate Summary Table
Project Cost Units
Total Capital Cost
Capital Cost $0
$0
$0
$
$Land Acquisition Cost
Amortized Capital and Land Cost
Total O&M Cost
Groundwater Production Charge
O&M Cost
$ per Year
$0
$43,251
$0
$ per Year
$ per Year
$ per YearEnergy Cost
Total Unit Cost
Total Annual Cost
Project Yield
$43,251
0.7
$ per Yr
AFY
Capital Cost Unit Cost
GPC Unit Cost
$0 $ per AF
$ per AF
$ per AF
$ per AF
$ per AF
$0
O&M Unit Cost $58,321
$0Energy Unit Cost
Unit Cost $58,321
Programmatic Cost Estimate
Project Costs Project Yield and Cost
Project
General Assumptions
Staff Time
Staffing Cost - Salary and Benefits
Calculations
Assumptions Units Cost Source Notes Rain Barrel
Yield (AFY)
0.1
0.1
0.2
CY Count Cost ($/yr)
$43,251
$43,251
$43,251
0.25
$167,000
FTE
$/FTE
Assuming 0.25 FTE per City input 2024
2025
2026
1
2
3
Project Yield 2027 4 0.3 $43,251
Available NOAA data for Palo Alto storm events was
filtered to remove storm events that were too small (less
than half an inch of rainfall) or too close together (less
than 5-days apart). Data is from 2000 to 2017.
Assumed that each inch of rainfall will fill a rain barrel.
Approximated 100 gallon rain barrel size.
NOAA Climate Data Online Palo Alto
Rainfall DataAdjusted average annual rainfall 4.9 inches
2028 5 0.3 $43,251
Rain Collected 100 gal/in-rainfall 2029
2030
2031
2032
2033
2034
2035
2036
2037
2038
2039
2040
2041
2042
2043
2044
2045
6 0.4
0.5
0.5
0.6
0.6
0.7
0.8
0.8
0.9
1.0
1.0
1.1
1.2
1.2
1.3
1.4
1.4
16.3
$43,251
$43,251
$43,251
$43,251
$43,251
$43,251
$43,251
$43,251
$43,251
$43,251
$43,251
$43,251
$43,251
$43,251
$43,251
$43,251
$43,251
$951,521
Gal/Rain Barrel
Average annual rainfall
Rain Barrel Lifespan
490
0.00150
20
gal/yr
AF/Barrel
years
$
7
8
9
Cost to City/Barrel $35 Palo Alto Rain Barrel Rebate Program
(Palo Alto, 2021, Table 11)
Palo Alto's portion of rain barrel rebate 10
11
12
13
14
15
16
17
18
19
20
21
22
Single Family Accts (2040)
Total Adoption Rate 2040
Total Barrels 2023 - 2040
Additional Barrels per Year
Annual savings rate
Savings in 2045
18,869
0.05
accts Single family account projections in 2045
Assuming 5% adoption from UWMP 2045 projection
943.5
43
device
device
AFY0.1
1.4 AFY
Total Savings 16.3 AF
Total Costs
Annual Staffing Cost $41,750
$1,501Annual Rain Barrels Rebate Costs
Annual Program Costs
Lifetime Costs (through year 2045)
Unit Cost ($/AF)
43 barrels per year at 35 per rain barrel
$43,251
$952,000
$58,350 Total (through 2045)
37
OCTOBER 2024 / FINAL / CAROLLO
APPENDIX D SUPPLY PORTFOLIO TOOL
DOCUMENTATION
CITY OF PALO ALTOONE WATER PLAN APPENDIX D
APPENDIX D
OCTOBER 2024 / FINAL / CAROLLO
APPENDIX D EVALUATION TOOL DOCUMENTATION
1.1 Introduction
The Palo Alto One Water Evaluation Tool (Tool) was created to compare up to eight portfolios composed
of up to 12 water supply sources. The Tool can also evaluate combinations of up to 12 water conservation
programs. The Tool compares options and portfolios based on their cost, full yield, and dry year yield, as
well through a criteria analysis that includes eight criteria.
1.1.1 Organization
This Tool is organized in a series of worksheets or tabs. The user can begin with the Readme tab for
instructions on how to use the Tool. The user inputs and analysis tabs are numbered from one to six and
are intended to be completed and reviewed in order. These include 1. User Inputs, 2. Option Yield and
Cost Comparison, 3. Conservation Program Comparison, 4. Portfolio Selection, 5. Portfolio Cost, and
6. Criteria Analysis. The model tabs include the calculations used to generate the results and graphics in
the Tool. These include the Supply Model, Cost Model, and Criteria Model.
1.2 Readme
The Readme tab includes a short summary of the purpose and how to use the Tool and includes a short
summary for what is included in each tab. This tab also includes a legend, shown in Table 1, explaining the
color coding for each of the cell types found in the Tool. This color coding is consistent across cells in the
Tool and the legend is shown on tabs that have user inputs. A screenshot of the readme tab is shown in
Figure 1.
Table 1 Legend for Cell Types
Cell Type
Users can input values to develop scenarios and portfolios. Used for naming
options and portfolios.User Input
Values from outside data sources. If any values are changed, provide
documentation of the changes under notes.Outside Source
Drop Down
Selection
Calculated Value
User inputs with drop-down menus to select an option based on the Lists tab.
NO ACTION: values based on formulas.
CITY OF PALO ALTO
ONE WATER PLAN D-1
APPENDIX D
OCTOBER 2024 / FINAL / CAROLLO
Figure 1 Readme Tab
CITY OF PALO ALTO
ONE WATER PLAN D-2
APPENDIX D
OCTOBER 2024 / FINAL / CAROLLO
Figure 2 User Inputs Tab
CITY OF PALO ALTO
ONE WATER PLAN D-3
APPENDIX D
OCTOBER 2024 / FINAL / CAROLLO
1.3 User Inputs
The User Inputs tab is the starting point for the Tool. The tab includes a Scenario Selection table with
drop down menus to develop scenario assumptions, as well as a series of five tables for the user input
Option Yield Assumptions, Demand Scenarios, Unit Cost, Capital Cost, and Evaluation Criteria. More
information about each of these tables is provided in the sections below. A screenshot of the user inputs
tab is shown in Figure 2.
1.3.1 Scenario Selection
The Scenario Selection table has five drop-down menus that allow the user to develop a scenario. Results
in all subsequent tabs use the scenario information selected by the user. Note that the Tool distinguishes
between the demand year and the cost year. This table includes the following selections:
Demand Year Projection: This drop-down menu allows the user to select the demand year used
in the portfolio normal and dry year supply analysis. Selection currently includes all years from
2023 to 2045.
Cost Year Projection: This drop-down menu allows the user to select the cost year used in the
option and portfolio cost analysis. Selection includes all years from 2023 to 2045.
Demand Scenario: This drop-down menu allows the user to select among three demand
scenarios (Low, Medium, High) as found in the Demand Scenarios table.
Emergency Shortage Stage: This drop-down menu allows the user to select the maximum
planned conservation savings from the implementation of Palo Alto's Water Shortage
Contingency Plan. The plan includes six stages: Stage I (Up to 10%), Stage II (Up to 20%), Stage III
(Up to 30%), Stage IV (Up to 40%), Stage V (Up to 50%), and Stage VI (greater than 50%).
Valley Water Transfer: This drop-down menu has two options (Yes, No) to select between the
No Valley Water Transfer and the Valley Water Transfer options under Option Yield in the Option
Yield Assumptions table.
1.3.2 Option Yield Assumptions
The Option Yield Assumptions table is used to set the yield, timeline, and dry year assumptions for RWS
Supply and up to 11 options. The table includes the following:
Option Names: The user creates names for each option. This table controls the option names in
all tables and graphics in Tool.
Option Yield: The user can input the yields for the No Valley Water Transfer and Valley Water
Transfer scenarios. RWS Supply is not included here as these are calculated values.
Start Year: The user can input the start year for each option. Note: this changes the Option
Timeline graphic in the Option Yield and Cost Comparison tab but does not change the timeline of
options in the option and portfolio supply analysis.
Dry Year Reductions: The user also selects the dry year reduction for each option. The dry year
reductions are applied to each option in the dry year supply analysis.
CITY OF PALO ALTO
ONE WATER PLAN D-4
APPENDIX D
OCTOBER 2024 / FINAL / CAROLLO
1.3.3 Demand Scenarios
The Demand Scenarios table includes the demand scenarios (Low, Medium, High) for the portfolio supply
analysis. The source of the demand scenarios and date accessed are provided under notes.
1.3.4 Unit Cost and Capital Cost
The Unit Cost ($/AF) and Capital Cost ($M) tables include the cost information by option used in the
option and portfolio cost analysis. Cost information has been imported from the One Water Screening
Cost Estimates spreadsheet, with date, filename, and cost escalation assumptions included under notes.
1.3.5 Evaluation Criteria
The Evaluation Criteria table includes the raw option scores and a drop-down menu of the criteria
weighting used in the criteria analysis. Some of the criteria, including Reliance on Tuolumne, Unit Cost, and
Reliability, are calculated separately in the Criteria Model tab. The table includes a check of the Total
Weight to ensure that it equals 100%, otherwise the following warning is shown: “Weighting does not
equal 100%.”
1.4 Options
The Option Yield and Cost Comparison tab provides graphical summaries for the information provided
in the User Inputs tab. This tab includes the Option Timeline and Yield Comparison which compares the
full yield in normal years, and the dry year yield based on the dry year reduction selected by the user for
each scenario. RWS is not shown in the Yield Comparison as this supply is calculated separately for each
portfolio. The tab also includes the Unit Cost and Capital Cost based on the cost year selected by the user.
Time series graphics of Unit Cost and Capital Cost are also included. A screenshot of the Projects tab with
the option yield and cost comparison is shown in Figure 3.
1.5 Conservation Program Comparison
The Conservation Program Comparison tab is used to evaluate changes to the conservation programs
included Enhanced Conservation Phase 1 and Enhanced Conservation Phase 2. The User is able to name up
to 12 conservation programs, provide the annual savings in AFY, the number of years to saturation, and
indicate whether an option is included in Phase 1 or Phase 2 using the drop-down selection. The graphics
shown include a Conservation Program Savings Summary showing the AF savings in 2045 for each
conservation program, and the Conservation Program Annual Savings Summary showing the annual
savings for the Phase 1 and Phase 2 based on the user inputs and selections.
Note that the changes to conservation program assumptions in this tab do not change the supply or cost
assumptions in this model. Changes to the conservation programs can be evaluated in this tab and
changes can be made in the Option Yield and Unit Cost assumptions in the User Inputs tab. The
functionality in this tab was kept separate from the option yield assumptions in order to maintain
consistency with the option specific information in the One Water Plan. A screenshot of the Water
Conservation tab with the conservation program comparison is shown in Figure 4.
CITY OF PALO ALTO
ONE WATER PLAN D-5
APPENDIX D
OCTOBER 2024 / FINAL / CAROLLO
Figure 3 Projects Tab with Options Yield and Cost Comparisons
CITY OF PALO ALTO
ONE WATER PLAN D-6
APPENDIX D
OCTOBER 2024 / FINAL / CAROLLO
Figure 4 Conservation Program Comparison Tab
CITY OF PALO ALTO
ONE WATER PLAN D-7
APPENDIX D
OCTOBER 2024 / FINAL / CAROLLO
1.6 Portfolio Selection
The Portfolio Selection tab is used to dynamically develop up to eight portfolios composed of up to 12
combinations of options. The user creates names for each portfolio under Portfolio Names and uses the
drop-down menus under each option to select the options included in each portfolio. RWS Supply is
included in each Portfolio and cannot be unselected. If the user attempts to select more than one Water
Reuse option within a portfolio, the following warning is shown: “Only Select One Water Reuse Option per
Portfolio”.
The Portfolio Selection tab includes two graphics used to evaluate the performance of each portfolio
under the selected scenario. The Normal Year Portfolio shows the normal year assumptions for each of the
portfolios, and the Dry Year Portfolio shows the dry year assumption for each of the portfolios. Both
graphics are based on the Demand Year Projection selected from the drop-down menu in the User Inputs
tab. An Unplanned Shortage is shown if the dry year supply yield for a portfolio is unable to meet
demands after accounting for the Shortage Stage selected from the drop-down menus in the User Inputs
tab. A screenshot of the Portfolio Selection worksheet is shown in Figure 5.
1.7 Portfolio Costs
The Portfolio Costs tab provides graphical summaries of the cost information for the portfolios selected
in Portfolio Selection tab. This tab includes the Weighted Unit Cost by Portfolio, which summarizes the
relative contribution of each option to the total unit cost of each portfolio. The second graphic includes
the Total Capital Cost by option for each portfolio. The cost results for both of these graphics are based
on the normal year yield for each portfolio. A screenshot of the Portfolio Cost worksheet is shown in
Figure 6.
1.8 Criteria Analysis
The Criteria Analysis tab allows the user to compare the results of the criteria analysis. Note that these
results include calculated outputs based on the scenario developed in the User Inputs tab. The Weighted
Criteria Ranking by Option table compares results by option using the scoring and weights from the User
Inputs table. The Weighted Criteria Ranking by Portfolio table compares results by portfolio based on the
contribution of each option to the portfolio. A screenshot of the Criteria Analysis tab is shown in Figure 7.
CITY OF PALO ALTO
ONE WATER PLAN D-8
APPENDIX D
OCTOBER 2024 / FINAL / CAROLLO
Figure 5 Portfolio Selection Tab
CITY OF PALO ALTO
ONE WATER PLAN D-9
APPENDIX D
OCTOBER 2024 / FINAL / CAROLLO
Figure 6 Portfolio Cost Tab
CITY OF PALO ALTO
ONE WATER PLAN D-10
APPENDIX D
OCTOBER 2024 / FINAL / CAROLLO
Figure 7 Criteria Analysis Tab
CITY OF PALO ALTO
ONE WATER PLAN D-11
APPENDIX D
OCTOBER 2024 / FINAL / CAROLLO
1.9 Model Tabs
There are three analysis tabs. The Supply Model tab includes the calculations used for the normal year
and dry year analysis. The Cost Model tab calculates the projected Unit Cost, Capital Cost, Total Annual
Cost, and Weighted Unit Cost. A screenshot of the Supply and Demand Model tab is shown in Figure 8.
1.9.1 Supply Model
This model calculates the normal and dry year yields for each portfolio. This tab includes the Normal Year
Supply Analysis, Dry Year Supply Analysis, and Enhanced Conservation Analysis.
1.9.1.1 Normal Year Supply Analysis
The normal year supplies for each portfolio are calculated based on the selected Demand Scenario, Valley
Water Transfer, and Option Yield from User Inputs tab. A linear interpolation formula is used to generate
annual water demands in each forecast year. Each portfolio includes the individual options selected from
the Portfolio Selection tab. The demand for RWS Supply is calculated as the difference between the total
demand for the selected scenario and the total yield for the selected supplies in the portfolio.
1.9.1.2 Dry Year Supply Analysis
The dry year supplies for each portfolio are calculated based on the selected Demand Scenario, Valley
Water Transfer, Yield, and Dry Year Reduction from User Inputs tab. Each portfolio includes the individual
options selected from the Portfolio Selection tab. All options include the Dry Year Reduction. The
available supply from RWS Supply is calculated as the Normal Year Supply for that year multiplied by the
Dry Year Reduction. Supply shortages are mitigated based on the Emergency Shortage Stage selected in
the User Inputs tab.
1.9.1.3 Enhanced Conservation Analysis
The graphical outputs from the Conservation Program Comparison tab are also calculated in the
Supply Model tab. These include the annual savings and program savings summary for the Enhanced
Conservation Phase 1 and Enhanced Conservation Phase 2. Note that changes to conservation program
assumptions do not change the cost or supply model. That information comes from the cost estimate
spreadsheet information input into the User Inputs tab.
1.9.2 Cost Model
This model calculates the annual unit cost, capital cost, total annual cost, and weighted unit cost for each
option and portfolio. A screenshot of the Cost Model tab is shown in Figure 9.
1.9.2.1 Unit Cost
These tables provide the unit costs for options that have been selected as part of each portfolio based on
the unit costs in the User Inputs tab. The unit cost for each option in the selected Cost Year Projection is
shown graphically in the Option Yield and Cost Comparison tab.
CITY OF PALO ALTO
ONE WATER PLAN D-12
APPENDIX D
OCTOBER 2024 / FINAL / CAROLLO
Figure 8 Supply and Demand Model Tab
CITY OF PALO ALTO
ONE WATER PLAN D-13
APPENDIX D
OCTOBER 2024 / FINAL / CAROLLO
Figure 9 Cost Model Tab
CITY OF PALO ALTO
ONE WATER PLAN D-14
APPENDIX D
OCTOBER 2024 / FINAL / CAROLLO
1.9.2.2 Capital Cost
These tables provide the capital costs for options that have been selected as part of each portfolio based
on the capital costs in the User Inputs tab.
1.9.2.3 Total Annual Cost
The total annual cost is calculated by multiplying the normal year yield for each option in the portfolio by
the unit cost for the selected cost year. These tables are used as an intermediate step in calculating the
weighted unit cost.
1.9.2.4 Weighted Unit Cost
The weighted unit cost is calculated by dividing the total annual cost for each option in the portfolio by
the total demand in that year. The weighted unit cost and capital costs are shown graphically in the
Portfolio Cost tab.
1.9.3 Criteria Model
This tab calculates the criteria scoring for each option and portfolio. This includes separate steps for
option scores, and portfolio scores. A screenshot of the Criteria Model tab is shown in Figure 10.
1.9.3.1 Option Scores
The Option Scores include raw and weighted scores. The weighted scores are calculated by multiplying the
raw scores by the criteria weights selected in the User Inputs tab. Scores include a combination of inputs
and calculated scores. Wise Use of Water, Ecological Benefit, Implementation Timeline, Operational
Complexity, and Public Acceptance are inputs from in the User Inputs tab. The following scores are
calculated based on the user selections for the Demand Year Projection and Cost Year Projection:
Reliance on Tuolumne is scored based on the ability of the supply to reduce Palo Alto's reliance
on supplies from the Tuolumne. Criterion is scored on a linear scale using the full yield in a
normal year with the largest yield scored as 5 and no yield scored at 1. RWS Supply is scored as a
1.
Unit Cost is scored based on the unit cost for each option. The criterion is scored on a linear scale
based on the Unit Cost in the selected Cost Year with the lowest non-zero cost scored as 5 and
the highest cost scored at 1.
Reliability is scored based on the ability to mitigate an RWS Supply shortage. The criterion is
scored on a linear scale using the Dry Year Yield with the highest yield scored as 5 and 0 AFY
scored at 1. RWS Supply is scored as a 1.
CITY OF PALO ALTO
ONE WATER PLAN D-15
APPENDIX D
OCTOBER 2024 / FINAL / CAROLLO
Figure 10 Criteria Model Tab
CITY OF PALO ALTO
ONE WATER PLAN D-16
APPENDIX D
OCTOBER 2024 / FINAL / CAROLLO
1.9.3.2 Portfolio Scores
The Portfolio Scores include raw and weighted scores. The raw scores are calculated using the weighted
average of the raw score for each option and the normal year supply for each option under the selected
Demand Year Projection in the User Inputs tab. The weighted scores are calculated by multiplying the raw
scores by the criteria weights selected in the User Inputs tab. Scores include a combination of inputs and
calculated scores. Wise Use of Water, Ecological Benefit, Implementation Timeline, Operational Complexity,
and Public Acceptance are from in the User Inputs tab. The following scores are calculated based on the
user selections for the Demand Year Projection and Cost Year Projection:
Reliance on Tuolumne is scored based on the ability of the portfolio to reduce the reliance on
supplies from the Tuolumne. Scored on a linear scale based on RWS Supply demand under
normal year conditions under the selected demand year with the lowest demand scored as 5 and
the highest demand scored at 1.
Unit Cost is scored based on portfolio unit cost from highest to lowest. The criterion is scored on
a linear scale with the lowest unit cost scored as 5 and the highest unit cost scored at 1.
Reliability is scored based on the dry year RWS Supply shortage in each portfolio. The criterion is
scored on a linear scale using the Unplanned Shortage in the selected Demand Year with the
lowest shortage scored as 5 and the highest shortage scored at 1.
1.9.4 Lists Tab
The Lists tab includes drop down menus and other lists used in the model. A screenshot of the List tab is
shown in Figure 11.
CITY OF PALO ALTO
ONE WATER PLAN D-17
APPENDIX D
OCTOBER 2024 / FINAL / CAROLLO
Figure 11 Lists Tab
CITY OF PALO ALTO
ONE WATER PLAN D-18
OCTOBER 2024 / FINAL / CAROLLO
APPENDIX E SENSITIVITY ANALYSIS
CITY OF PALO ALTOONE WATER PLAN APPENDIX E
APPENDIX E
OCTOBER 2024 / FINAL / CAROLLO
APPENDIX E SENSITIVITY AND SCENARIO ANALYSIS
Chapter 5, section 5.6 examines how the OWP findings change when the evaluation criteria are weighted
differently and under different assumptions about future supply and demand. Section 5.6 presents and
discusses the findings of the sensitivity and scenario analysis, and this appendix provides the numeric
results for all criteria and weighting percentages listed in Table 5.8. The yellow highlighting indicates
which criteria weight is changed compared to the initial weighting used in the OWP analysis.
1.1 Raw Scores and Weighted Scores
The raw and weighted criteria scores by portfolio are based on the medium demand scenario, and a RWS
Supply reduction of 50%, combined with the implementation of a Shortage Stage II (up to 20%) in year
2045. The scores below assume for Portfolio G (Enhanced Conservation with Regional DPR) that the Valley
Water Transfer is implemented (selected “yes” in the Tool) while all other portfolios assume that the Valley
Water Transfer is not implemented (selected “no” in the Tool).
Table 1 Raw Criteria Scores by Portfolio with Initial Weighting
Portfolio
A. Baseline 2.0
2.3
2.7
2.3
3.1
2.7
2.6
2.0
2.2
1.9
2.4
2.2
2.2
2.2
1.0
1.4
2.9
2.1
2.9
3.1
2.0
5.0
4.7
3.3
4.4
3.2
3.5
4.2
5.0
4.8
3.4
4.5
3.3
3.6
4.8
5.0
4.8
4.1
4.5
3.7
4.0
4.4
4.7
5.0
1.0
2.9
3.5
1.3
4.1
1.0
1.7
4.1
2.4
4.0
3.9
2.6
25.7
27.1
23.3
25.6
26.0
24.4
26.9
B. Enhanced Conservation Phase 1 and 2
C. Enhanced Conservation with Desalination
D. Enhanced Conservation with Groundwater
E. Enhanced Conservation with Palo Alto DPR
F. Enhanced Conservation with IPR
G. Enhanced Conservation with Regional DPR
CITY OF PALO ALTOONE WATER PLAN E-1
APPENDIX E
OCTOBER 2024 / FINAL / CAROLLO
Table 2 Weighted Criteria Scores by Portfolio with Initial Weighting
Portfolio
Weighting 10%
0.20
0.23
0.27
0.23
0.31
0.27
0.26
10%
0.20
0.22
0.19
0.24
0.22
0.22
0.22
10%
0.10
0.14
0.29
0.21
0.29
0.31
0.20
5%5%5%20%
0.95
1.00
0.20
0.59
0.70
0.26
0.81
35% 100%
A. Baseline 0.25
0.24
0.17
0.22
0.16
0.18
0.21
0.25
0.24
0.17
0.22
0.17
0.18
0.24
0.25
0.24
0.21
0.22
0.19
0.20
0.22
0.35
0.60
1.43
0.85
1.39
1.37
0.90
2.5
2.9
2.9
2.8
3.4
3.0
3.1
B. Enhanced Conservation Phase 1 and 2
C. Enhanced Conservation with Desalination
D. Enhanced Conservation with Groundwater
E. Enhanced Conservation with Palo Alto DPR
F. Enhanced Conservation with IPR
G. Enhanced Conservation with Regional DPR
CITY OF PALO ALTOONE WATER PLAN E-2
APPENDIX E
OCTOBER 2024 / FINAL / CAROLLO
1.2 Unit Cost Weighting
This sensitivity analysis adjusts the Unit Cost criterion weighting from 20%, to 5% in the lower weighting
scenario and 50% in the higher weighting scenario.
Table 3 Weighted Criteria Scores by Portfolio with Lower Unit Cost Weighting
Portfolio
Weighting 12%
0.24
0.28
0.32
0.28
0.37
0.32
0.31
12%
0.24
0.26
0.22
0.28
0.26
0.26
0.26
12%
0.12
0.17
0.34
0.25
0.35
0.36
0.24
6%6%6%5%42% 100%
A. Baseline 0.30
0.28
0.20
0.26
0.19
0.21
0.25
0.30
0.29
0.20
0.27
0.20
0.21
0.29
0.30
0.29
0.25
0.27
0.22
0.24
0.26
0.24
0.25
0.05
0.15
0.18
0.07
0.20
0.42
0.71
1.70
1.01
1.65
1.62
1.06
2.1
2.5
3.3
2.8
3.4
3.3
2.9
B. Enhanced Conservation Phase 1 and 2
C. Enhanced Conservation with Desalination
D. Enhanced Conservation with Groundwater
E. Enhanced Conservation with Palo Alto DPR
F. Enhanced Conservation with IPR
G. Enhanced Conservation with Regional DPR
Table 4 Weighted Criteria Scores by Portfolio with Higher Unit Cost Weighting
Portfolio
Weighting 6%6%6%3%3%3%50%
2.37
2.50
0.50
1.47
1.75
0.66
2.03
22% 100%
A. Baseline 0.13
0.15
0.17
0.15
0.19
0.17
0.16
0.13
0.14
0.12
0.15
0.14
0.14
0.14
0.06
0.09
0.18
0.13
0.18
0.19
0.12
0.16
0.15
0.10
0.14
0.10
0.11
0.13
0.16
0.15
0.11
0.14
0.10
0.11
0.15
0.16
0.15
0.13
0.14
0.12
0.13
0.14
0.22
0.37
0.90
0.53
0.87
0.85
0.56
3.4
3.7
2.2
2.8
3.5
2.4
3.4
B. Enhanced Conservation Phase 1 and 2
C. Enhanced Conservation with Desalination
D. Enhanced Conservation with Groundwater
E. Enhanced Conservation with Palo Alto DPR
F. Enhanced Conservation with IPR
G. Enhanced Conservation with Regional DPR
CITY OF PALO ALTOONE WATER PLAN E-3
APPENDIX E
OCTOBER 2024 / FINAL / CAROLLO
1.3 Reliability Weighting
This sensitivity analysis adjusts the Reliability criterion weighting from 35%, to 20% in the lower weighting
scenario and 50% in the higher weighting scenario.
Table 5 Weighted Criteria Scores by Portfolio with Lower Reliability Weighting
Portfolio
Weighting 12%
0.25
0.29
0.33
0.29
0.38
0.34
0.25
12%
0.25
0.27
0.23
0.29
0.27
0.27
0.25
12%
0.12
0.18
0.35
0.26
0.36
0.38
0.12
6%6%6%25%
1.16
1.23
0.25
0.72
0.86
0.33
1.16
20% 100%
A. Baseline 0.31
0.29
0.20
0.27
0.20
0.22
0.31
0.31
0.30
0.21
0.28
0.21
0.22
0.31
0.31
0.30
0.25
0.28
0.23
0.25
0.31
0.20
0.34
0.82
0.49
0.79
0.78
0.20
2.9
3.2
2.6
2.9
3.3
2.8
2.9
B. Enhanced Conservation Phase 1 and 2
C. Enhanced Conservation with Desalination
D. Enhanced Conservation with Groundwater
E. Enhanced Conservation with Palo Alto DPR
F. Enhanced Conservation with IPR
G. Enhanced Conservation with Regional DPR
Table 6 Weighted Criteria Scores by Portfolio with Higher Reliability Weighting
Portfolio
Weighting 8%8%8%4%4%4%15%
0.73
0.77
0.15
0.45
0.54
0.20
0.62
50% 100%
A. Baseline 0.15
0.18
0.21
0.18
0.24
0.21
0.20
0.15
0.17
0.14
0.18
0.17
0.17
0.17
0.08
0.11
0.22
0.17
0.23
0.24
0.15
0.19
0.18
0.13
0.17
0.12
0.13
0.16
0.19
0.19
0.13
0.17
0.13
0.14
0.19
0.19
0.19
0.16
0.17
0.14
0.15
0.17
0.50
0.86
2.05
1.22
1.99
1.95
1.28
2.2
2.6
3.2
2.7
3.6
3.2
2.9
B. Enhanced Conservation Phase 1 and 2
C. Enhanced Conservation with Desalination
D. Enhanced Conservation with Groundwater
E. Enhanced Conservation with Palo Alto DPR
F. Enhanced Conservation with IPR
G. Enhanced Conservation with Regional DPR
CITY OF PALO ALTOONE WATER PLAN E-4
APPENDIX E
OCTOBER 2024 / FINAL / CAROLLO
1.4 Environmental Benefits Weighting
This analysis adjusts the Environmental Benefits criterion weighting from a total of 30%, to 15% in the
lower weighting scenario and 45% in the higher weighting scenario.
Table 7 Weighted Criteria Scores by Portfolio with Lower Environmental Benefits Weighting
Portfolio
Weighting 5%5%5%6%6%6%24%
1.15
1.21
0.24
0.71
0.85
0.32
0.99
43% 100%
A. Baseline 0.10
0.12
0.13
0.12
0.15
0.14
0.13
0.10
0.11
0.09
0.12
0.11
0.11
0.11
0.05
0.07
0.14
0.11
0.15
0.15
0.10
0.30
0.29
0.20
0.27
0.20
0.21
0.25
0.30
0.29
0.21
0.27
0.20
0.22
0.29
0.30
0.29
0.25
0.27
0.23
0.24
0.27
0.43
0.73
1.74
1.03
1.69
1.66
1.09
2.7
3.1
3.0
2.9
3.6
3.1
3.2
B. Enhanced Conservation Phase 1 and 2
C. Enhanced Conservation with Desalination
D. Enhanced Conservation with Groundwater
E. Enhanced Conservation with Palo Alto DPR
F. Enhanced Conservation with IPR
G. Enhanced Conservation with Regional DPR
Table 8 Weighted Criteria Scores by Portfolio with Higher Environmental Benefits Weighting
Portfolio
Weighting 15%
0.30
0.35
0.40
0.35
0.46
0.41
0.39
15%
0.30
0.33
0.28
0.36
0.33
0.33
0.33
15%
0.15
0.21
0.43
0.32
0.44
0.46
0.30
4%4%4%16%
0.74
0.79
0.16
0.46
0.55
0.21
0.64
28% 100%
A. Baseline 0.20
0.19
0.13
0.17
0.13
0.14
0.16
0.20
0.19
0.13
0.18
0.13
0.14
0.19
0.20
0.19
0.16
0.18
0.15
0.16
0.17
0.28
0.47
1.13
0.67
1.09
1.07
0.70
2.4
2.7
2.8
2.7
3.3
2.9
2.9
B. Enhanced Conservation Phase 1 and 2
C. Enhanced Conservation with Desalination
D. Enhanced Conservation with Groundwater
E. Enhanced Conservation with Palo Alto DPR
F. Enhanced Conservation with IPR
G. Enhanced Conservation with Regional DPR
CITY OF PALO ALTOONE WATER PLAN E-5
APPENDIX E
OCTOBER 2024 / FINAL / CAROLLO
1.5 Ease of Implementation Weighting
This analysis adjusts the Ease of Implementation criterion weighting from a total of 15%, to 0% in the
lower weighting scenario and 30% in the higher weighting scenario.
Table 9 Weighted Criteria Scores by Portfolio with Lower Ease of Implementation Weighting
Portfolio
Weighting 12%
0.24
0.27
0.32
0.27
0.36
0.32
0.31
12%
0.24
0.26
0.22
0.28
0.26
0.26
0.26
12%
0.12
0.17
0.34
0.25
0.35
0.36
0.23
0%0%0%24%
1.11
1.18
0.24
0.69
0.82
0.31
0.96
41% 100%
A. Baseline 0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.41
0.71
1.69
1.00
1.64
1.61
1.05
2.1
2.6
2.8
2.5
3.4
2.9
2.8
B. Enhanced Conservation Phase 1 and 2
C. Enhanced Conservation with Desalination
D. Enhanced Conservation with Groundwater
E. Enhanced Conservation with Palo Alto DPR
F. Enhanced Conservation with IPR
G. Enhanced Conservation with Regional DPR
Table 10 Weighted Criteria Scores by Portfolio with Higher Ease of Implementation Weighting
Portfolio
Weighting 8%8%8%10%
0.50
0.47
0.33
0.44
0.32
0.35
0.42
10%
0.50
0.48
0.34
0.45
0.33
0.36
0.48
10%
0.50
0.48
0.41
0.45
0.37
0.40
0.44
16%
0.78
0.82
0.16
0.48
0.58
0.22
0.67
29% 100%
A. Baseline 0.16
0.19
0.22
0.19
0.25
0.22
0.21
0.16
0.18
0.15
0.20
0.18
0.18
0.18
0.08
0.12
0.24
0.18
0.24
0.25
0.16
0.29
0.49
1.18
0.70
1.14
1.12
0.74
3.0
3.3
3.0
3.1
3.4
3.1
3.3
B. Enhanced Conservation Phase 1 and 2
C. Enhanced Conservation with Desalination
D. Enhanced Conservation with Groundwater
E. Enhanced Conservation with Palo Alto DPR
F. Enhanced Conservation with IPR
G. Enhanced Conservation with Regional DPR
CITY OF PALO ALTOONE WATER PLAN E-6
APPENDIX E
OCTOBER 2024 / FINAL / CAROLLO
1.6 Demand Scenarios
This sensitivity analysis adjusts Palo Alto’s demands from the low demand to high demand scenarios.
Table 11 Weighted Criteria Scores by Portfolio with Lower Demand Scenario
Portfolio
A. Baseline 0.20
0.24
0.28
0.24
0.33
0.29
0.27
0.20
0.23
0.18
0.25
0.23
0.23
0.23
0.10
0.15
0.32
0.24
0.33
0.35
0.22
0.25
0.23
0.15
0.21
0.15
0.16
0.20
0.25
0.24
0.16
0.22
0.15
0.17
0.24
0.25
0.24
0.20
0.22
0.17
0.19
0.22
0.94
1.00
0.20
0.78
0.74
0.44
0.87
0.35
0.65
1.63
0.94
1.58
1.55
1.00
2.5
3.0
3.1
3.1
3.7
3.4
3.2
B. Enhanced Conservation Phase 1 and 2
C. Enhanced Conservation with Desalination
D. Enhanced Conservation with Groundwater
E. Enhanced Conservation with Palo Alto DPR
F. Enhanced Conservation with IPR
G. Enhanced Conservation with Regional DPR
Table 12 Weighted Criteria Scores by Portfolio with Higher Demand Scenario
Portfolio
A. Baseline 0.20
0.23
0.27
0.23
0.31
0.27
0.26
0.20
0.22
0.19
0.24
0.22
0.22
0.22
0.10
0.14
0.28
0.21
0.29
0.30
0.20
0.25
0.24
0.17
0.22
0.16
0.18
0.21
0.25
0.24
0.17
0.22
0.17
0.18
0.24
0.25
0.24
0.21
0.22
0.19
0.20
0.22
0.94
1.00
0.20
0.78
0.74
0.44
0.87
0.35
0.59
1.41
0.84
1.37
1.35
0.88
2.5
2.9
2.9
3.0
3.4
3.1
3.1
B. Enhanced Conservation Phase 1 and 2
C. Enhanced Conservation with Desalination
D. Enhanced Conservation with Groundwater
E. Enhanced Conservation with Palo Alto DPR
F. Enhanced Conservation with IPR
G. Enhanced Conservation with Regional DPR
CITY OF PALO ALTOONE WATER PLAN E-7
APPENDIX E
OCTOBER 2024 / FINAL / CAROLLO
1.7 RWS Supply Reliability Scenarios
This sensitivity analysis adjusts Palo Alto’s required cutback from the RWS Supply and Palo Alto’s
implemented Shortage Stage of the Water Shortage Contingency Plan.
Table 13 RWS Reliability (30% RWS Supply Cutback/Shortage Stage II)
Portfolio
A. Baseline 0.20
0.23
0.27
0.23
0.31
0.27
0.26
0.20
0.22
0.19
0.24
0.22
0.22
0.22
0.10
0.14
0.28
0.21
0.29
0.30
0.20
0.25
0.24
0.17
0.22
0.16
0.18
0.21
0.25
0.24
0.17
0.22
0.17
0.18
0.24
0.25
0.24
0.21
0.22
0.19
0.20
0.22
0.94
1.00
0.20
0.78
0.74
0.44
0.87
0.35
0.79
1.75
1.04
1.75
1.75
1.27
2.5
3.1
3.2
3.2
3.8
3.5
3.5
B. Enhanced Conservation Phase 1 and 2
C. Enhanced Conservation with Desalination
D. Enhanced Conservation with Groundwater
E. Enhanced Conservation with Palo Alto DPR
F. Enhanced Conservation with IPR
G. Enhanced Conservation with Regional DPR
Table 14 RWS Reliability (50% RWS Supply Cutback/Shortage Stage III)
Portfolio
A. Baseline 0.20
0.23
0.27
0.23
0.31
0.27
0.26
0.20
0.22
0.19
0.24
0.22
0.22
0.22
0.10
0.14
0.28
0.21
0.29
0.30
0.20
0.25
0.24
0.17
0.22
0.16
0.18
0.21
0.25
0.24
0.17
0.22
0.17
0.18
0.24
0.25
0.24
0.21
0.22
0.19
0.20
0.22
0.94
1.00
0.20
0.78
0.74
0.44
0.87
0.35
0.72
1.75
1.09
1.75
1.75
1.15
2.5
3.0
3.2
3.2
3.8
3.5
3.4
B. Enhanced Conservation Phase 1 and 2
C. Enhanced Conservation with Desalination
D. Enhanced Conservation with Groundwater
E. Enhanced Conservation with Palo Alto DPR
F. Enhanced Conservation with IPR
G. Enhanced Conservation with Regional DPR
CITY OF PALO ALTOONE WATER PLAN E-8
OCTOBER 2024 / FINAL / CAROLLO
APPENDIX F STAKEHOLDER ENGAGEMENT MATERIALS
This Appendix include presentations materials from the following stakeholder engagement meetings:
Stakeholder Engagement #1: Community Needs and Priorities (9/28/2022)
Stakeholder Engagement #2: Exploring Water Supply and Conservation Options (12/6/2022)
Stakeholder Engagement #3: Sharing Initial Analysis Results (6/3/2024)
CITY OF PALO ALTOONE WATER PLAN APPENDIX F
APPENDIX F
OCTOBER 2024 / FINAL / CAROLLO
Stakeholder Engagement #1: Community Needs and Priorities
(9/28/2022)
CITY OF PALO ALTOONE WATER PLAN
Stakeholder Engagement #1: Community
Needs and Priorities
09/28/2022
CITY OF PALO ALTO
ONE WATER PLAN
First Community Workshop
to discuss
COMMUNIT
Y
NEEDS &
PRIORITIESSeptember 28, 2022
6:00 pm - 7:30 pm
Palo Alto City Hall
https://cityofpaloalto.zoom.us/j/89411156856
1
// Introductions – Palo Alto Team
Utilities Department Staff
Karla Dailey
Assistant Director Lisa Bilir
Senior Resource Planner
Linda GrandSustainability ProgramsAdministrator
Rebecca OliverAssociate ResourcePlanner
Public Works Department Staff
Karin North
Assistant Director
Samantha Engelage Pam Boyle Rodriguez
Stormwater Compliance
Program Manager
Elise Sbarbori
Environmental Control
Program Manager
Senior Engineer/Pretreatment Program
Manager 2
2
1
Stakeholder Engagement #1: Community
Needs and Priorities
09/28/2022
// Introductions – Carollo Team
Inge Wiersema Rachel Duncan Jacquelin Mutter Maddi Rasmus
Project Manager Project Engineer Technical Advisor Staff Engineer
3
3
// Agenda
1. Welcome & Opening Remarks (10 mins)
2. Project Background (10 mins)
6:00-6:10 pm
6:10-6:20 pm
6:20-6:25 pm
6:25-6:30 pm
6:30-7:15 pm
7:15-7:30 pm
3. One Water Plan Overview (5 min)
4. City Water Supplies Overview (10 min)
5. Community Needs & Priorities Discussion (45 min)
6. Meeting Close (15 min)
4
4
2
Stakeholder Engagement #1: Community
Needs and Priorities
09/28/2022
// First Community Workshop Housekeeping
. In-person Logistics
•
•
•
Sign up to speak/comment during the Community Needs and Priorities discussion
Use microphone at table, cell phone handy for live polls
Please hold your questions until the dedicated Q&A pauses
. Virtual Logistics
•
•
•
•
Participants are muted by default
Enter your question/comment into the chat box, questions will be addressed at the dedicated Q&A pauses
Cell phone or web browser handy for live polls
During the Community Needs and Priorities discussion, raise your virtual hand to speak (or press *9 onyour phone) and let us know if you would like to turn on your video
. We want to hear from you! Thank you for contributing your comments andideas during this listening session.
•We will do our best to address all questions possible, keeping time constraints in mind
5
5
// One Water Plan Roadmap in Uncertain Future
. The One Water Plan:
• Is a Key Action in Sustainability and Climate Action Plan
• Is a long-term 20-year (through 2045) Water Supply Plan
• Addresses future uncertainty such as SFPUC supply reliability, droughts,
and climate change
• Includes robust and meaningful stakeholder engagement
• Is being completed by an outside consultant Carollo Engineers, a National
One Water Thought Leader
• Builds on existing plans/work
. What the One Water Plan does not address:
• Current ongoing drought
• Short-term emergencies such as earthquakes and wildfires – addressed
under separate emergency plans
6
3
Stakeholder Engagement #1: Community
Needs and Priorities
09/28/2022
Project Background
7
// There are many drivers for the One Water Plan
Increased Housing Needs Supply Reliability
(multi-year droughts)
Recreational Water Needs
(e.g., Boronda Lake)
Limited Funding
Regulatory Changes Increased Public
Awareness
Decisions about Joining
Regional Efforts
Instream Flows
& Habitat Needs
Climate Change
8
8
4
Stakeholder Engagement #1: Community
Needs and Priorities
09/28/2022
Source: WRF #4660 (2017)// What is One Water?
9
9
// The One Water Mindset: Think Differently
All Water Has Value Integration
Consider the entire water cycle Sustainable water management solutions,
also linking land use, energy, etc.
Collaboration
Breaking down institutional silos,
incl. non-water sector partners
Inclusion
From Elected officials to
Community organizations
Multi-benefits
Broaden project goals like resilience,
climate change, and water equity
Innovation
Embrace new technology and plan
for future regulatory conditions
10
10
5
Stakeholder Engagement #1: Community
Needs and Priorities
09/28/2022
// One Water Plan Goal and Objective
Council adoption of a One Water supply plan that is
a 20-year adaptable roadmap for implementation
of prioritized water supply and conservation
portfolio alternatives
GOAL
Address how the City of Palo Alto can mitigate
the impact of future uncertainties such as severe
multi-year drought, changes in climate, water
demand, and regulations through integrated
water resources supply planning
OBJECTIVE
11
11
One Water Plan Overview
12
6
Stakeholder Engagement #1: Community
Needs and Priorities
09/28/2022
// One Water involves watershed-based solutions and collaboration to
address water management challenges for a more reliable water future
13
13
// One Water Plan Process Overview
14
14
7
Stakeholder Engagement #1: Community
Needs and Priorities
09/28/2022
// Roadmap to One Water Plan
TODAY Sharing Initial
Results(~Feb 2023)
RecommendedSupply Strategy
Trigger-basedImplementation
StraFundingStrategySupply &Conservation
PortfoliosWater Supply &
ConservationOptions
Data
Gathering Community Needsand Priorities
(Sept 2022)
Assessment
of unknowns SupplyOptions
Screening Final OWP
(~Aug 2023)
Evaluation
Criteria
Draft Criteria &Exploring Water Supply and
Conservation Options
(~Nov 2022)
15
15
Pause for Q&A
16
16
8
Stakeholder Engagement #1: Community
Needs and Priorities
09/28/2022
City’s Water Supplies Overview
17
// Regional Water Supply System from
San Francisco Public Utilities Commission (SFPUC)
18
18
9
Stakeholder Engagement #1: Community
Needs and Priorities
09/28/2022
// Palo Alto Distribution System
19
19
// City of Palo Alto Water and Recycled Water
Distribution Systems
Drinking Water Recycled Water
. 5 Receiving Stations connected to . Distributes recycled water from the
SFPUC Water System (58 MGD)RWQCP to:
. 8 emergency wells within the city . City of Mountain View
(19 MGD). Palo Alto facilities (including the
Municipal Golf Course, Municipal
Services Center, Animal Services
Facility, and Greer Park)
. 7 reservoirs (13 MG storage)
. 6 interties to adjacent water
agencies:
• Mountain View
• Stanford
• Purissima Hills
. Palo Alto uses approximately 0.28
MGD of recycled water (2.8% of total
water demand)
MG = million gallons; MGD = million gallons per day;
RWQCP = Regional Water Quality Control Plant
20
20
10
Stakeholder Engagement #1: Community
Needs and Priorities
09/28/2022
Pause for Q&A
21
21
Community Needs & Priorities
22
11
Stakeholder Engagement #1: Community
Needs and Priorities
09/28/2022
// Please share your thoughts!
23
23
// What do you think is the biggest risk to long-term reliable
water supply in Palo Alto? (select up to 2)
. Climate Change (impact on water supply)
. Droughts (temporary water use reductions)
. Environmental Regulations
. Sea Level Rise (impact on groundwater and water quality)
. Increased Demand (resulting from housing requirements)
. Impaired Water Quality
. Wasteful Water Use
. Emergency Disruptions (e.g., earthquakes or wildfires)
24
24
12
Stakeholder Engagement #1: Community
Needs and Priorities
09/28/2022
// Which of the following best reflect your top 3 water
management priorities? (select up to 3)
. Water supply reliability
. Drinking water quality
. Surface water quality/watershed health
. Protection of tree canopy health
. Affordability
. Sustainability
25
25
// Which of the following water supply and conservation
alternatives are most important for Palo Alto (select up to 3)?
. Increased indoor water conservation
. Increased outdoor water conservation
. Increased use of non-potable recycled water
. Purified water for drinking (potable reuse)
. Utilization of groundwater
. Stormwater capture and use
. Desalination (SF Bay or brackish groundwater)
26
26
13
Stakeholder Engagement #1: Community
Needs and Priorities
09/28/2022
// Should Palo Alto invest in alternative water supplies to
increase drought reliability?
. Yes
. No
. SFPUC should invest in alternative water supplies
27
27
// What water use cutback percentage do you think is
acceptable for the Palo Alto community during a drought?
. 10%
. 20%
. 30%
. 40%
. 50%
28
28
14
Stakeholder Engagement #1: Community
Needs and Priorities
09/28/2022
// What is your perspective on the water future for Palo Alto?
(e.g., drinking water, groundwater, recycled water, stormwater, gray water, water conservation)
. Very optimistic
. Optimistic
. Neutral
. Worried
. Very Worried
29
29
// Open Discussion: Community Priorities for the One Water
Plan
. In-person: add your name to the listand approach the table with themicrophone to speak when yourname is called
. Virtual: Send your responses to theHost via chat
Indicate whether you would like to go
“live” by raising virtual hand or
pressing * 9 on your phone. Let us
know if you would like to turn on your
video.
30
30
15
Stakeholder Engagement #1: Community
Needs and Priorities
09/28/2022
// What are the most important outcomes for Palo Alto
from this One Water Plan?
Increased
Green Spaces &
Tree canopy
Increased
Affordability
Environmental
Protection
1
31
// Roadmap to One Water Plan
Sharing InitialResults
(~Feb 2023)
Recommended
Supply Strategy
Trigger-basedImplementationStraFunding
StrategySupply &ConservationPortfoliosWater Supply &
Conservation
Options
Data Gathering Community Needs
and Priorities(Today)
Assessment
of unknowns Supply
Screening Final OWP(~Aug 2023)
Evaluation
Criteria
Draft Criteria &
Exploring Water Supply andConservation Options
(~Nov 2022)
32
32
16
Stakeholder Engagement #1: Community
Needs and Priorities
09/28/2022
Next Steps
33
// We need to hear your voice!
Please join us for the next 2 community meetings:
. Meeting #1: Community Needs & Priorities
. Meeting #2: Draft Criteria & Exploring Water Supply Options (~Nov 2022)
. Meeting #3: Sharing the Initial Results (~Feb 2023)
. We will share out to our distribution list/email/website/social media the link
to the Draft One Water Plan (~June 2023)
Subscribe to the One Water email
distribution list to receive updates
https://bit.ly/3qDWcXY
34
34
17
Stakeholder Engagement #1: Community
Needs and Priorities
09/28/2022
// Other Upcoming Events
.
.
.
.
.
Oct. 1, Rain Barrel Workshop: Learn how rain barrels can improve your property, conserve water, save
money, and help protect local creeks.
•10:00 am - 11:30 am at SummerWinds Nursery, 725 San Antonio Rd.
Oct. 5, Bay Area SunShares Informational Webinar: Learn about how to receive discounts for rooftop solar
and battery storage.
•6:30pm - 7:30pm, Zoom webinar
Oct. 15, Making Better Choices in Your Home Workshop: Learn about different climate-friendly choices
you can make in your home.
•10:00 am – 1:00 pm, Mitchell Park Community Center, 3700 Middlefield Rd.
Oct. 18, Landscape Design 101 – How to Get Started: Learn how to create your own low water/lowmaintenance garden.
•7:00 pm - 8:30 pm, Zoom Webinar
Nov. 1, Lawn Conversion 101: Learn how to create your own low water/low maintenance garden.
•7:00 pm - 8:30 pm, Zoom Webinar
35Register and learn more at CityofPaloAlto.org/Workshops
35
Meeting Close
36
18
Stakeholder Engagement #1: Community
Needs and Priorities
09/28/2022
CITY OF PALO ALTO
ONE WATER PLAN
THANK
YOU!
ADDITIONAL
INFORMATION,
PLEASE CONTACT:
Lisa Bilir, City of Palo Alto
E: lisa.bilir@cityofpaloalto.org
P: (650) 329-2543
37
EXTRA GRAPHICS
38
38
19
Stakeholder Engagement #1: Community
Needs and Priorities
09/28/2022
// Meeting #2: What are the categories of supply and
conservation options this project will assess…
Water Reuse Stormwater
Capture & Use Water Supply Option
Groundwater Water Conservation Option
Water Storage
Outdoor Conservation
Agency Transfers
Indoor Conservation
Valley Water Treated Water
Other 39
39
20
APPENDIX F
OCTOBER 2024 / FINAL / CAROLLO
Stakeholder Engagement #2: Exploring Water Supply and Conservation
Options (12/6/2022)
CITY OF PALO ALTOONE WATER PLAN
Stakeholder Engagement #2: Exploring Water
Supply and Conservation Options
12/06/2022
CITY OF PALO ALTO
ONE WATER PLAN
Community Stakeholder
Workshop #2
EXPLORING
WATER
SUPPLY OPTIONS
December 6, 2022
5:30 pm - 7:00 pm
Mitchell Park Community
Center
https://cityofpaloalto.zoom.us/j/86907772889
1
// Introductions – Palo Alto Team
Utilities Department Staff
Karla Dailey
Assistant Director Lisa Bilir
Senior Resource Planner
Linda Grand
Sustainability ProgramsAdministrator
Rebecca Oliver
Associate ResourcePlanner
Public Works Department Staff
Welcome to City
officials!
Karin North
Assistant Director
Samantha Engelage Pam Boyle Rodriguez
Stormwater Compliance
Program Manager
Elise Sbarbori
Environmental Control
Program Manager
Senior Engineer/Pretreatment Program
Manager 2
2
1
Stakeholder Engagement #2: Exploring Water
Supply and Conservation Options
12/06/2022
// Introductions – Carollo Team
Inge Wiersema Rachel Duncan Jacquelin Mutter Maddi Rasmus
Project Manager Project Engineer Technical Advisor Staff Engineer
3
3
// Agenda
1. Welcome & Opening Remarks (10 min)
2. One Water Plan Overview (10 min)
5:30 - 5:40 pm
5:40 - 5:50 pm
5:50 - 6:15 pm3. Potential Water Supply Options (25 min)
4. Draft Supply Option Screening & Evaluation Criteria (40 min) 6:15 - 6:55 pm
5. Next Steps & Meeting Close (5 min) 6:55 - 7:00 pm
4
4
2
Stakeholder Engagement #2: Exploring Water
Supply and Conservation Options
12/06/2022
// Housekeeping
. This meeting will be recorded and posted on the City website
. Please hold your questions until the dedicated Q&A pauses
. In-person Logistics
•Raise your hand to speak
. Virtual Logistics
•
•
•
Participants are muted by default
Enter your questions/comments into the chat
Indicate whether you would like to go “live” by raising virtual hand or pressing * 9 on your phone
. Cell phone or web browser handy for live polls
. We want to hear from you! Thank you for contributing your
comments and ideas during this listening session.
5
5
One Water Plan Overview
6
3
Stakeholder Engagement #2: Exploring Water
Supply and Conservation Options
12/06/2022
// One Water Plan Roadmap in Uncertain Future
. The One Water Plan:
• Is a Key Action in Sustainability and Climate Action Plan
• Is a long-term 20-year (through 2045) Water Supply Plan
• Addresses future uncertainty such as SFPUC supply reliability, droughts,and climate change
• Includes robust and meaningful stakeholder engagement
• Is being completed by an outside consultant Carollo Engineers, a National
One Water Thought Leader
• Builds on existing plans/work
. What the One Water Plan does not directly address:
• Current ongoing drought
• Short-term emergencies such as earthquakes and wildfires – addressed
under separate emergency plans
7
// There are many drivers for the One Water Plan
Increased Housing Needs Supply Reliability
(multi-year droughts)
Recreational Water Needs
(e.g., Boronda Lake)
Limited Funding
Regulatory Changes Increased Public
Awareness
Decisions about Joining
Regional Efforts
Instream Flows
& Habitat Needs
Climate Change
8
8
4
Stakeholder Engagement #2: Exploring Water
Supply and Conservation Options
12/06/2022
// Roadmap to One Water Plan
Sharing Initial
Results(~Feb 2023)
RecommendedSupply Strategy
Trigger-basedImplementation
StraFundingStrategySupply &Conservation
PortfoliosWater Supply &
ConservationOptions
Data
Gathering Community Needsand Priorities
(Sept 2022)
Assessment
of unknowns SupplyOptions
Screening Final OWP
(~Aug 2023)
Evaluation
Criteria
Exploring Water
Supply Options
(Dec 2022)
TODAY
9
9
// As you may recall… In September we asked about community
priorities for the One Water Plan
Sharing Initial Recommended
Supply StrategyResults
(~Feb 2023)Trigger-basedImplementationStraFunding
StrategySupply &
ConservationPortfoliosWater Supply &
Conservation
Options
Data
Gathering Community Needs
and Priorities(Sept 2022)
Assessment
of unknowns Supply
Screening Final OWP(~Aug 2023)
Evaluation
Criteria
Exploring WaterSupply Options
(Dec 2022)
10
10
5
Stakeholder Engagement #2: Exploring Water
Supply and Conservation Options
12/06/2022
// What is the 3-Step Water Supply Evaluation Process?
Potential Water Supply
and Conservation Options Themed
Project Portfolios
Recommended
ImplementationStrategy
Portfolio
Evaluation
Criteria
Pre-
Screening Project
Screening
Criteria
“C”A B C D
~25 options ~15 options 4 portfolios 1 supply portfolio
. Supply Availability
. Supply Resilience
. Community Benefits
. Estimated Yield (afy)
. Ongoing/Already . Life Cycle Costs ($/acre-ft)Planned . Increases supply reliability
in drought years?. Not feasible at this
time .Environmental Benefits
. Other?. Life Cycle Cost. Moving forward . Ease of Implementation 11
11
// What is the 3-Step Water Supply Evaluation Process?
Requesting your
input today!Sharing how we are using
input received at the first
meetingPotential WaterSupplyand ConservationOptions Themed
Project Portfolios RecommendedImplementationStrategy
Portfolio
Evaluation
Criteria
Pre-
Screening
Project
Screening
Criteria
“C”A B C D
~25 options ~15 options 4 portfolios 1 supply portfolio
12
12
6
Stakeholder Engagement #2: Exploring Water
Supply and Conservation Options
12/06/2022
// Supply and Conservation Option Evaluation Process
Q&A
13
13
Potential Water Supply &
Conservation Options
14
7
Stakeholder Engagement #2: Exploring Water
Supply and Conservation Options
12/06/2022
// Supply and conservation options categories that this
project will assess
Groundwater
Conservation Water Reuse
Other Stormwater Capture & Use
Imported Water 15
15
// Supply and conservation options category:
Water Conservation
Conservation
•Planned/ongoing
conservation
•New conservation actions
•Customer side water
loss reduction
16
8
Stakeholder Engagement #2: Exploring Water
Supply and Conservation Options
12/06/2022
// Planned and ongoing City of Palo Alto
water conservation programs
. Water Conservation Tools and Resources:
• WaterSmart customer web portal
• Waterfluence large landscape irrigation budget program
• Seasonal landscape workshops
. Landscape efficiency rebates in partnership with Valley Water:
• Landscape Conversion
• Graywater Laundry to Landscape
• Irrigation Upgrades
• Stormwater Rebates
. Advanced metering program
. Distribution system water loss reduction
Learn more at Cityofpaloalto.org/waystosave
17
17
// Supply and conservation options category:
Groundwater
Groundwater •Converting emergency
supply wells
•City park groundwater
irrigation
18
18
9
Stakeholder Engagement #2: Exploring Water
Supply and Conservation Options
12/06/2022
// Supply and conservation options category:
Water Reuse
Water Reuse
•
•
Non-potable reuse
Direct potable reuse (City
facility)
•
•
•
Direct potable reuse
(regional facility)
Indirect potable reuse
(groundwater injection)
Indirect potable reuse (Lake
Lagunita groundwater
recharge)
•
•
Graywater capture & reuse
Blackwater capture & reuse
19
19
// Supply and conservation options category:
Stormwater Capture and Use
Stormwater Capture & Use
•
•
Residential or commercial-scale
stormwater capture
Green stormwater infrastructure
20
20
10
Stakeholder Engagement #2: Exploring Water
Supply and Conservation Options
12/06/2022
// Supply and conservation options category:
Imported Water
•
•
SFPUC supply
Valley Water treated water (via
new pipeline)
•Interagency transfer agreement Imported Water 21
21
// Supply and conservation options category:
Other
•
•
•
•
•
•
•
Atmospheric water generators
Local surface water reservoir
Regional storage
Multi-source storage
Desalination
Temporary dewatering sites
Permanent dewatering sites
Other
22
22
11
Stakeholder Engagement #2: Exploring Water
Supply and Conservation Options
12/06/2022
// Water supply and conservation options:
Feedback & new ideas
23
23
Draft Supply Option Screening &
Evaluation Criteria
24
12
Stakeholder Engagement #2: Exploring Water
Supply and Conservation Options
12/06/2022
// Step 1: Pre-Screening
Pre-
Screening
~15 options
.. OOnnggooini ngg/A/ Al rlreeaaddyy SharingPPl al annnneedd initial.. VNi aobtifleitaysfirbolme atptrheivsitoimusestudies results
.. MMoovvi ni nggf oforrwwaarrdd
25
25
// Initial Pre-screening of Supply and Conservation Options
3 Preliminary Screening Categories
Ongoing
or already
planned
Not
feasible at
this time
Moving
forward
26
26
13
Stakeholder Engagement #2: Exploring Water
Supply and Conservation Options
12/06/2022
// Initial Pre-screening of Supply and Conservation Options:
Ongoing or already planned
. Planned/ongoing conservation
. Advanced metering program
. Distribution system water loss reduction
. Non-potable reuseOngoing or
already
planned . SFPUC imported water supply
27
27
// Initial Pre-screening of Supply and Conservation Options:
Not feasible at this time
. Deemed Infeasible in Previous Studies
• Temporary dewatering sites
• Interagency transfer agreement
. Excessive Cost or Complexity
• Blackwater capture and reuse
• Atmospheric water generatorsNot feasible
at this time • Local surface water reservoir
• Valley Water treated water (via new pipeline). Outside of City Control
• Indirect potable reuse at Lake Lagunita
(groundwater recharge)
• Regional storage
28
28
14
Stakeholder Engagement #2: Exploring Water
Supply and Conservation Options
12/06/2022
// Initial Pre-screening of Supply and Conservation Options:
Moving forward
. New conservation actions
. Converting emergency supply wells
. City park groundwater irrigation
. Direct potable reuse (via regional facility or City facility)
. Indirect potable reuse via groundwater injection
. Expanded non-potable reuse
Moving
forward
. Permanent dewatering (as part of reuse options)
.Graywater capture and reuse
. Stormwater capture (residential/commercial-scale or GSI)
. Multi-source below-ground storage (e.g. stormwater detention)
. Desalination
. Other ideas from today: _____________________
29
29
// Initial Pre-Screening Results
Feedback and Q&A
30
30
15
Stakeholder Engagement #2: Exploring Water
Supply and Conservation Options
12/06/2022
// Step 3: Draft Portfolio Evaluation Criteria
Sharing how we are using input
received at the first meeting… and
requesting your input on
importance
Portfolio
Evaluation
Criteria
..SSuupppplylyAAvvaailialabbiliiltiyty
..SSuupppplylyRReessiliileiennccee
..CCoommmmuunnitiytyBBeenneefiftists
..EEnnvvi riroonnmmeenntatallBBeenneefiftists
..LLifiefeCCyyccleleCCoosstt
..EEaasseeooffImImppl el emmeenntatatitoionn 31
31
// Asking for your feedback!
Upcoming Mentimeter exercise to rank these criteria
Scale these criteria based on relative importance.
32
32
16
Stakeholder Engagement #2: Exploring Water
Supply and Conservation Options
12/06/2022
// Evaluation Criteria – Supply Availability and Resilience
Community Priorities:Evaluation Criteria:
Which of the following best reflect your top 3 water management
priorities?Supply Availability
•
•
Normal year reliability
Dry year reliability
Supply Resilience
Vulnerability risk score
(resilience to
•
uncertainties)
33
33
// Evaluation Criteria – Community Benefits and
Environmental Benefits
Community Priorities:Evaluation Criteria:
Which of the following best reflect your top 3 water management
priorities?Community Benefits
Water quality
Water equity
•
•
Environmental Benefits
•
•
Tree canopy health
Sustainable water
supplies
•Watershed health
34
34
17
Stakeholder Engagement #2: Exploring Water
Supply and Conservation Options
12/06/2022
// Evaluation Criteria – Life Cycle Cost
Community Priorities:Evaluation Criteria:
What do you think are the barriers to the use of
more water sources?Life Cycle Cost
$/acre-foot cost of each
portfolio
•
35
35
// Evaluation Criteria – Ease of Implementation
Community Priorities:
Evaluation Criteria:What do you
think are the
barriers to the
use of more
Ease of Implementation
Implementation timeline
Operational complexity
Alignment with other efforts
Public acceptance
•
•
•
•
•
•
water sources?
Regulatory complexity
Funding opportunities
What do you
think is the key
to One Water
success?
36
36
18
Stakeholder Engagement #2: Exploring Water
Supply and Conservation Options
12/06/2022
// Please share your thoughts!
37
37
// Summary of Evaluation Criteria
Supply Availability Supply Resilience Life Cycle Cost
• Normal year reliability
• Dry year reliability
• Vulnerability risk score(resilience to
uncertainties)
• $/acre-foot cost of each
portfolio
Community Benefits Environmental Benefits Ease of Implementation
• Water quality
• Water equity
• Tree canopy health
• Sustainable water
supplies
• Implementation timeline
• Operational complexity
• Alignment with otherefforts• Watershed health
• Public acceptance
• Regulatory complexity
• Funding opportunities 38
38
19
Stakeholder Engagement #2: Exploring Water
Supply and Conservation Options
12/06/2022
// Step 2: Draft Screening Criteria and Portfolio Themes
Requesting your
input!ThemedProject Portfolios
Screening
Criteria
A B C D
. Estimated Yield (afy)
. Life Cycle Costs ($/acre-ft)
. Increases supply reliability
in drought years?
. Other?
39
39
// Supply and Conservation Options Draft Screening Criteria
Initial ideas and input discussion
Draft Screening Criteria
Estimated Supply Yield
Metric/Unit Potential Range
acre-foot per year High: 2,000+ afy
Medium: 100-2,000 afy
Low: 0-100 afy
(afy)
Life Cycle Cost dollar per acre-foot $: <$2,000/acre-ft
($/acre-ft)$$: $2,000-$4,000/acre-ft
$$$: >$4,000/acre-ft
Increases supply reliability in
drought years?
qualitative Yes
Neutral
No
Other Criteria
40
40
20
Stakeholder Engagement #2: Exploring Water
Supply and Conservation Options
12/06/2022
// Portfolio Theme Ideas
Requesting your input!Required
MaximizeLocalSupplies
MaximizeDroughtResilience
SustainableWaterSupplies
BaselinePortfolio MinimizeCost OtherThemes
Business asusual, onlyimplementing
already
What mix ofoptions What mix ofoptions arerenewable,equitable,and protectthe
What mix ofoptionsWhat mix ofoptions willhave the further enable the
City to bestmitigate theimpact of
planned increase the
City’s localwatersupplies the
most?
projects andprograms.lowestcombinedsupply cost?environment
the most?Baseline forPortfoliocomparison
droughts?
41
41
Next Steps
42
21
Stakeholder Engagement #2: Exploring Water
Supply and Conservation Options
12/06/2022
// Thank you for your input today!
Sharing Initial
Results RecommendedSupply StrategyPlease join us at
the next meeting!
(~Feb 2023)Trigger-basedImplementation
StraFundingStrategySupply &Conservation
PortfoliosWater Supply &
ConservationOptions
Data Gathering Community Needsand Priorities
(Sept 2022)
Assessment
of unknowns SupplyScreening Final OWP
(~Aug 2023)
Evaluation
Criteria
Exploring Water
Supply Options
(Today)
43
43
// We need to hear your voice!
Please join us for the next community meeting:
. Meeting #1: Community Needs & Priorities
. Meeting #2: Exploring Water Supply Options
. Meeting #3: Sharing the Initial Results (~Feb 2023)
. We will share out to our distribution list/email/website/social media the link
to the Draft One Water Plan (~June 2023)
Subscribe to the One Water email
distribution list to receive updates
https://bit.ly/3qDWcXY
44
44
22
Stakeholder Engagement #2: Exploring Water
Supply and Conservation Options
12/06/2022
// Other Upcoming Events
. Dec. 16 – 17th, Lawn Busters DIY Workshop: discover the facets of drought-tolerant
gardening, species selection, spacing, and general care and maintenance
•
•
12/16 - 6:00pm - 7:00pm, virtual
12/17 - 9:30am-12:30 pm, in-person
Register and learn more at ourcityforest.org/diylawnbust
45
45
Meeting Close
46
23
Stakeholder Engagement #2: Exploring Water
Supply and Conservation Options
12/06/2022
CITY OF PALO ALTO
ONE WATER PLAN
THANK
YOU!
ADDITIONAL
INFORMATION,
PLEASE CONTACT:
Lisa Bilir, City of Palo Alto
E: lisa.bilir@cityofpaloalto.org
P: (650) 329-2543
47
24
APPENDIX F
OCTOBER 2024 / FINAL / CAROLLO
Stakeholder Engagement #3: Sharing Initial Analysis Results (6/3/2024)
CITY OF PALO ALTOONE WATER PLAN
Stakeholder Engagement #3: Sharing
Initial Analysis Results
06/03/2024
One Water
Plan:
Initial ResultsUtilities Advisory Commission
June 3, 2024 www.cityofpaloalto.org
1
One Water Initial Results
Outline
1. Goal, Overview & Approach
2. Supply and Conservation Projects
3. Water Supply & Conservation
Portfolios
4. Initial Conclusions
5. Next Steps
2 www.cityofpaloalto.org
2
1
Stakeholder Engagement #3: Sharing
Initial Analysis Results
06/03/2024
Previous UAC Meetings on One Water
Plan
• July 7, 2021 – One Water Plan Draft Scope
• February 1, 2023 – One Water Plan Update;
provided update on screening process,
stakeholder engagement and portfolio
approach
3 www.cityofpaloalto.org
3
One Water Plan:
Goal
Council adoption of a One
Water supply plan that is a
20-year adaptable roadmap
for implementing prioritized
portfolio alternatives for
water supply and
conservation
4 www.cityofpaloalto.org
4
2
Stakeholder Engagement #3: Sharing
Initial Analysis Results
06/03/2024
One Water Plan:
Approach•
•
•
•
•
•
Key Acon in City’s Sustainability and Climate Acon Plan (SCAP)
Long-term 20-year (through 2045) Water Supply Plan
Addresses future uncertainties
Includes robust and meaningful stakeholder engagement
In collaboration with Carollo Engineers, a national One Water thought leader
Builds on exisng plans/work
One Water Plan does not directly address:
•
•
Near-term drought
Short-term emergencies such as earthquakes and wildfires – addressed under separate
emergency plans
•Building codes
5 www.cityofpaloalto.org
5
Key Uncertainties
• Valley Water Transfer
• About half of effluent from Regional Water Quality Control Plant
• Option expires in 2033
• Transfer incompatible with some Palo Alto water supply options
• Future Water Supply Availability (varies by water supply project)
• Droughts
• Climate Change
• State regulations
• SFPUC’s alternative water supply implementation
• Cost
6 www.cityofpaloalto.org
6
3
Stakeholder Engagement #3: Sharing
Initial Analysis Results
06/03/2024
One Water Plan:
Overview
(Summer 2024)
(End of 2024)
2
7 www.cityofpaloalto.org
7
Water Supply and Conservation
Project
Screening
.
.
Environmental
Benefits
Ease of
Implementation
Cost
Reliability
.
.
8 www.cityofpaloalto.org
8
4
Stakeholder Engagement #3: Sharing
Initial Analysis Results
06/03/2024
Screening Results:
Top Water Supply Projects
Baseline - SFPUC (Regional Water System; Current Potable Water Supply)
Conservation Phase 1
Conservation Phase 2
Groundwater Full Treatment (Iron, Manganese, Total Dissolved Solids)
Groundwater Blending
Direct Potable Reuse - Palo Alto Facility
Direct Potable Reuse - Regional Facility
Direct Potable Reuse - Palo Alto Facility with Small Salt Removal Facility
Indirect Potable Reuse
Bay Water Desalination
Note: full list of water supply and conservation options attached to this presentation, and schematics
on upcoming slides
9 www.cityofpaloalto.org
9
Enhanced Conservation Phase 1 &
2
Possible Measures
Conservation Phase 1 Conservation Phase 2
Outdoor irrigation assistance for commercial customers High Efficiency Toilet direct install for commercial
customers
Non- functional turf ban for commercial customers Turf conversion support for residential customers
Front lawn limitation for residential new developments
and major retrofits
Front lawn limitation for residential properties upon resale
Permanent 3-day watering week restriction
Low-income residential High Efficiency Toilet direct install
10 www.cityofpaloalto.org
10
5
Stakeholder Engagement #3: Sharing
Initial Analysis Results
06/03/2024
Groundwater Options
Groundwater with blending plus Iron (Fe), Manganese (Mn) and Total Dissolved Solids (TDS)
treatment SFPUC Water
Groundwater Blending Only (no treatment) –
not carried forward in One Water Plan, need to understand public acceptance
11 www.cityofpaloalto.org
11
Direct Potable Reuse
(DPR)
DPR Treatment Facility with three possible
configurations:
1) Palo Alto DPR Facility
Or
2) Regional DPR Facility owned by Valley
Water, if effluent transfer occurs
Or
3) Palo Alto DPR Facility that utilizes the
Small Salt Removal Facility currently being
built at the Regional Water Quality Control
Plant
12 www.cityofpaloalto.org
12
6
Stakeholder Engagement #3: Sharing
Initial Analysis Results
06/03/2024
Indirect Potable Reuse
(IPR)
13 www.cityofpaloalto.org
13
Baywater Desalination
14 www.cityofpaloalto.org
14
7
Stakeholder Engagement #3: Sharing
Initial Analysis Results
06/03/2024
Project Normal Year Yield
Comparison
(Acre Feet per Year)
15 www.cityofpaloalto.org
15
Project Unit Cost Per Acre Foot
Comparison
16 www.cityofpaloalto.org
16
8
Stakeholder Engagement #3: Sharing
Initial Analysis Results
06/03/2024
Project Compatibility With Valley
Water
Effluent Transfer No Valley Water
Transfer
With Valley Water
Transfer
Baseline - SFPUC (Regional Water System; Current Potable Water Supply)
Conservation Phase 1
Conservation Phase 2
Groundwater Full Treatment (Fe, Mn, TDS)
Groundwater Blending
No
Direct Potable Reuse - Palo Alto Facility
Direct Potable Reuse - Regional Facility
Direct Potable Reuse - Palo Alto Facility with SSRF
Indirect Potable Reuse – Palo Alto Facility
Bay Water Desalination
No
No
Note: list of water supply and conservation options attached to this presentation
17 www.cityofpaloalto.org
17
Water Supply andConservationTool & Portfolios
18
9
Stakeholder Engagement #3: Sharing
Initial Analysis Results
06/03/2024
Tool for Water Supply Portfolio
Analysis
Data Inputs User Selections Outputs
Water Demand Forecast Future Scenario Assumptions Portfolio Supply
Summary
Project Yields Project Variables
Portfolio Costs
EstimatesProject Cost Estimates
Project Evaluation
Portfolio Development
Project Costs Estimates
Portfolio Evaluation
Portfolio Evaluation
Graphical Outputs
19 www.cityofpaloalto.org
19
Water Supply Portfolio Evaluation Criteria
&
Suggested Weights
Evaluation Criteria Weight
Reliability Reliability
Unit Cost
35%
20%
5%
5%
5%
10%
10%
10%
Suggested weights from
stakeholder engagement
meeting with community
and interdepartmental
staff as well as online
survey
Cost
Implementation Timeline
Operational Complexity
Public Acceptance
Wise Use of Water
Ecological Benefit
Reliance on Tuolumne
Ease of
Implementation
Environmental
Benefits
20 www.cityofpaloalto.org
20
10
Stakeholder Engagement #3: Sharing
Initial Analysis Results
06/03/2024
Initial Water Portfolio Evaluation Results
Weighted Criteria Ranking by Portfolio - No Valley Water Transfer -
2045 Evaluation Criteria
Note:
1) Each portfolio includes
Conservation Phase 1 and
Phase 2, except Baseline SFPUC
2) Each portfolio includes SFPUC
supply
21 www.cityofpaloalto.org
21
Initial Water Portfolio Evaluation Results
Weighted Criteria Ranking by Portfolio - With Valley Water Transfer -
2045 Evaluation Criteria
Note:
1) Each portfolio includes
Conservation Phase 1 and
Phase 2, except Baseline
SFPUC
2) Each portfolio includes
SFPUC supply
22 www.cityofpaloalto.org
22
11
Stakeholder Engagement #3: Sharing
Initial Analysis Results
06/03/2024
Initial Observations
• Conservation Phase 1 and Phase 2 score higher than “do nothing” and do not
require large investment to proceed (included in every portfolio other than the
SFPUC or “do nothing”)
• Highest Scoring Portfolios:
DPR - Palo Alto Only No Valley Water Transfer
DPR - Regional Facility with Valley Water
Transfer• Both DPR portfolios contingent on Valley Water Effluent Transfer; resolved in nine
years
• Baywater Desal is highest scoring portfolio not dependent on the Valley Water
Effluent Transfer
• Other high scoring portfolio is emergency supply well conversion with blending only
(no treatment); lower water quality so not included
23 www.cityofpaloalto.org
23
Sensitivity of Initial Results
Weighted Criteria Ranking by Portfolio - No Valley Water Transfer -
2045 Evaluation Criteria
Evaluation WeightCriteria
Reliability
Cost
20%
35%
5%
5%
5%
Ease of
Implementation
10%
10%
10%
Environmental
Benefits
Note:
1) Each portfolio includes
Conservation Phase 1 and
Phase 2, except Baseline SFPUC
2) Each portfolio includes SFPUC
supply
24 www.cityofpaloalto.org
24
12
Stakeholder Engagement #3: Sharing
Initial Analysis Results
06/03/2024
Sensitivity of Initial Results
Weighted Criteria Ranking by Portfolio - With Valley Water Transfer -
2045 Evaluation Criteria
Evaluation WeightCriteria
Reliability
Cost
20%
35%
5%
5%
5%
Ease of
Implementation
10%
10%
10%
Environmental
Benefits
Note:
1) Each portfolio includes
Conservation Phase 1 and
Phase 2, except Baseline
SFPUC
2) Each portfolio includes
SFPUC supply
25 www.cityofpaloalto.org
25
Initial Results Sensitivity to Cost
Weighting
• Top portfolios unchanged DPR - Palo Alto Only No Valley Water Transfer
DPR - Regional Facility with Valley Water Evaluation
Criteria Weight
Transfer Reliability 20%
• Conservation scores higher Cost 35%
15%
30%
Ease of
Implementation• Only the top scoring portfolio and Conservation
score higher than Baseline – SFPUC Environmental
Benefits• Groundwater blending only (no treatment) is
second-highest scoring infrastructure project and
scores higher than Baseline – SFPUC
26 www.cityofpaloalto.org
26
13
Stakeholder Engagement #3: Sharing
Initial Analysis Results
06/03/2024
Next Steps
UAC Final One Water Plan (Fall 2024)
• Recommended supply strategy
• Trigger-based implementation plan
City Council Final One Water Plan (End of 2024)
Future Activities
•
•
•
Funding Strategy
Implementation
Updating One Water Tool as conditions change
27 www.cityofpaloalto.org
27
14