HomeMy WebLinkAboutStaff Report 2603-61644.Preliminary Information on the City of Palo Alto's (City) 2025 Urban Water Management
Plan (2025 UWMP) (DISCUSSION: 8:35PM – 9:00PM) Late Packet Report added, Staff
Presentation
Utilities Advisory Commission
Staff Report
Report Type: NEW BUSINESS
Lead Department: Utilities
Meeting Date: March 31, 2026
Report #:2603-6164
TITLE
Preliminary Information on the City of Palo Alto's (City) 2025 Urban Water Management Plan
(2025 UWMP)
This will be a late packet report published on Thursday, March 26, 2026.
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Utilities Advisory Commission
Staff Report
From: Alan Kurotori, Director Utilities
Lead Department: Utilities
Meeting Date: March 31, 2026
Report #: 2602-6022
TITLE
Preliminary Information for Discussion on the City of Palo Alto's (City) Upcoming Draft 2025
Urban Water Management Plan (2025 UWMP)
RECOMMENDATION
This item is for discussion, and no action is requested. Key updates to the City’s Upcoming Draft
2025 UWMP are being presented to the Utilities Advisory Commission (UAC) for review and
feedback. Staff will return to the UAC in May 2026 with the Draft 2025 UWMP for a
recommendation to Council to adopt the 2025 UWMP.
EXECUTIVE SUMMARY
As part of the water planning process for urban water suppliers in California, Palo Alto is
required by state law to submit an Urban Water Management Plan (UWMP), which includes a
Water Shortage Contingency Plan (WSCP), to the California Department of Water Resources
(DWR) every five years. UWMPs are required by statute to report specific information about
water demand, water supply, demand management activities, alternative water supplies,
anticipated shortages during dry periods, and contingency plans for addressing those shortages.
The City’s UWMP supports its long-term resource planning to ensure that adequate water
supplies are available to meet existing and future water needs. UWMPs are not intended to
predict future demand but rather as a planning tool to ensure adequate supplies and demand
management strategies to meet future demand based on development plans. Palo Alto’s
UWMP does not change Palo Alto’s water rights1. UWMPs are useful to cities as well as to the
state in terms of providing a framework to review water reliability. The City’s UWMP housing
development assumptions align with its Regional Housing Needs Allocation (RHNA), which—
under state law—requires the City to plan for its fair share of future housing across all income
levels.
1 Palo Alto has a contractual right to 16.58 MGD of drinking water from the San Francisco Public Utilities
Commission during normal years called the Individual Supply Guarantee.
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Staff is in the process of updating the City’s 2025 UWMP, which must be adopted by City
Council and submitted to DWR by July 1, 2026 to remain eligible for DWR-administered and
other state grants and loans. The City’s current UWMP3 (2020 UWMP), was adopted by City
Council on June 7, 20214.
Long-term water demand projections: Total water demand is projected to decline by
5% over the 25-year forecast period.
Water reliability assessment: Based on current projected demands of wholesale
customers including Palo Alto (see Table 1 in the Analysis section), San Francisco Public
Utilities Commission (SFPUC)’s supply modeling shows water reliability projections for
two alternative future supply scenarios:
5 in multiple dry years
when compared to water supplies in an average year. In other words, RWS
Wholesale supplies could be reduced by up to 48% in a multi-year drought.
Water Shortage Contingency Plan (WSCP) – Water Use Restrictions: Water use
restrictions have been updated to reflect measures implemented during recent
droughts and new state legislation6.
3 City of Palo Alto’s 2020 Urban Water Management Plan:
https://www.paloalto.gov/files/assets/public/v/1/utilities/uwmp/2020-uwmp_final-submission-to-dwr.pdf
4 Resolution No. 9964:
https://recordsportal.paloalto.gov/WebLink/DocView.aspx?id=61418&dbid=0&repo=PaloAlto&searchid=f8133868
-b0ea-40c9-b3d6-32a145228f0b
5 Unless otherwise noted, this report reflects demand, supply, and reliability figures for SFPUC wholesale
customers only, rather than the entire Regional Water System (inclusive of SFPUC retail customers). The SFPUC
utilizes the Water Shortage Allocation Plan (WSAP) that is incorporated in the Water Supply Agreement between
the SFPUC and the wholesale customers to allocate the RWS supply available during dry years between the retail
customers and the wholesale customers. The WSAP, also known as the Tier 1 Plan, defines the method for
allocating between the retail customers collectively and wholesale customers collectively the available RWS
supplies during system-wide shortages.
6 California Assembly Bill 1572 (2023), codified at Water Code section 10618.14, prohibits the use of
potable/drinking water for irrigating nonfunctional turf at government and commercial, industrial, and institutional
(CII) properties, including homeowner associations (HOAs) common areas, statewide.
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Use and planned use of recycled water: City is no longer planning for expanding
recycled water use within the service area.
Attachments A-C of this report includes the water supply reliability data that is provided by the
SFPUC and will be used to populate the water supply reliability tables in the City’s 2025 UWMP.
During its May 2026 meeting, the UAC and the public will have the opportunity to review the
City’s full draft 2025 UWMP, which, in addition to the updates highlighted in this staff report,
will include updated descriptions of the water system’s service area, system supplies, water
demand, Demand Management Measures (DMMs), and full WSCP.
BACKGROUND
The Urban Water Management Planning Act (California Water Code, §§10610-
10656 and §10608) requires an urban water supplier, providing water for municipal purposes to
more than 3,000 customers or serving more than 3,000 acre-feet annually, to adopt an UWMP
every five years demonstrating water supply reliability in normal, single dry, and multiple dry
water years. A UWMP must also describe the City’s current water reliability, foreseeable future
needs, strategy for meeting those needs, and any challenges. The information collected from
UWMPs is useful for local, regional, and statewide water planning.
In order for the City, as an urban water supplier, to be eligible for any water grant or loan
administered by DWR, it must have a current UWMP on file that DWR determined addresses
the requirements of the California Water Code. A current UWMP must also be maintained by
the City throughout the term of any grant or loan administered by DWR. This requirement also
applies to the City’s outstanding loans administered by the State Water Resources Control
Board (SWRCB). As of fiscal year 2025, the City had $153.8 million in SWRCB loans outstanding,
and the City is drawing up to an additional $81.2 million on a reimbursement basis to finance
the Secondary Treatment Upgrades project at the Regional Water Quality Control Plant, which
is still under construction.
ANALYSIS
1.Long-term Water Demand Projections
The 2025 Water Demand and Conservation Projections (2025 Demand Study) were prepared in
coordination with Bay Area Water Supply & Conservation Agency (BAWSCA) to support regional
planning efforts and to facilitate preparation of member agencies’ 2025 Urban Water
Management Plan. The 2025 Demand Study is a direct input for the water demand, supply, and
reliability projections in the City’s 2025 UWMP. BAWSCA’s technical consultant, Hazen and
Sawyer, developed individual models for each BAWSCA member agency, utilizing information
provided by agencies on projected population, jobs, and housing growth to project water
demand through 2050. City staff worked with Hazen and Sawyer to develop and refine the
underlying assumptions for Palo Alto’s demand forecasts by using sources such as the City’s
Housing Element and the City’s current and planned participation in water conservation
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programs. More information about the inputs and methodology for the 2025 Demand Study
can be found in the 2025 Regional Demand Study Report11.
Calibration base period: Calibrating a model to a base period involves adjusting its parameters
to align outputs with historical data. For the 2025 Demand Study, the predicted per account
water use was calibrated to a base historical period between 2021-2023. This base period
followed a 2-year drought during which demand was near historic lows.
11 2025 Regional Water Demand and Conservation Study: https://bawsca.org/water/use/2025_Demand_Study
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Housing density and population: The 2025 City’s demand forecast uses higher population
projections compared to that of the 2020 Demand Study; however, this is offset by higher
housing density assumptions. Palo Alto’s demand forecast relies on ABAG 2040 projections
(consistent with the City’s current Housing Element) which assume higher population growth
compared to the 2020 Demand Study which relied on the City’s 2030 Comprehensive Plan.
Rates and price-elasticity: The 2025 demand forecast applies price-elasticity assumptions and
incorporates the City Council’s latest adopted 5-year rate plan as an input. As a result,
projected demand through 2030 is lower than it would be under an inflation-only assumption.
The 2020 Demand Study model included a price elasticity estimate and used historical rate data
for its forecast, but it did not include future approved rate plans.
13. Reliability is defined by
the amount and frequency of water delivery reductions (deficiencies) required to balance
customer demands with available supplies during droughts.
13 Section 10631(h):
https://leginfo.legislature.ca.gov/faces/codes_displaySection.xhtml?sectionNum=10631.&lawCode=WAT
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Bay-Delta Plan Amendment requires the release of 30-50% of the “unimpaired flow”15 on the
three tributaries from February through June in every year type. SFPUC assumes that the
required release is 40% of unimpaired flow in its modeling of the new flow standard.
15 "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." (Water Quality Control Plan for the San
Francisco Bay/Sacramento-San Joaquin Delta Estuary (Dec. 12, 2018) p.17, fn. 14, available at
https://www.waterboards.ca.gov/plans_policies/docs/2018wqcp.pdf.)
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Table 1. Retail and Wholesale RWS Demand Assumptions Used for Supply Reliability
Modeling (AFY) - 2025 UWMP vs 2020 UWMP
1 2030 through 2050 Wholesale Customer purchase projections were provided to the SFPUC by
BAWSCA on March 4, 2026, and include demands for the cities of San Jose and Santa Clara.
The 2025 UWMP cutback projections in Table 2 are assumed to apply to each wholesale
customer equally, and therefore also reflect the projected cutbacks for the City of Palo Alto.
The Tier 2 Drought Response Implementation Plan, which allocates the collective wholesale
customers’ share of available RWS supplies among each of the 26 wholesale customers during
dry years, only applies during system-wide shortages of 20% or less. Because the "With Bay-
Delta Plan" scenario results in wholesale cutbacks ranging from 31% to 48%, the Tier 2 Plan
cannot be applied. In the absence of a negotiated approach for allocating RWS supply among
the wholesale customers during shortages exceeding 20%, BAWSCA suggests that agencies
(including City) apply these cutbacks equally across all agencies for their 2025 UWMPs (see
Attachment A: Memo to Member Agencies). This approach is reflected in the above wholesale
supply cutback projections.
2025 2030 2035 2040 2045 2050
Retail 68,486 70,280 68,598 69,383 71,737 74,763
Wholesale1 145,827 150,087 152,777 157,597 161,520 166,340
Total 214,314 220,366 221,375 226,980 233,257 241,103
Retail 75,324 75,660 76,893 79,023 82,609
Wholesale 163,649 165,779 170,263 175,195 182,480
Total 238,973 241,439 247,155 254,217 265,090
2025 Urban Water Management Plan
2020 Urban Water Management Plan
Table 2: Projected RWS Supply Availability, With Bay-Delta Plan Amendment - 2025 UWMP vs 2020 UWMP
2030 2035 2040 2045 2050
31.1% 31.1% 42.2% 42.2% 42.2%
33.0% 33.0% 42.9% 42.9% 42.9%
35.2% 35.2% 45.1% 45.1% 45.1%
36.8% 36.8% 46.8% 46.8% 46.8%
38.4% 38.4% 48.4% 48.4% 48.4%
36.3% 36.5% 36.5% 45.5%
45.4% 45.6% 45.6% 45.5%
45.4% 45.6% 45.6% 45.5%
45.4% 45.6% 52.0% 53.7%
45.4% 50.1% 52.0% 53.7%
2025 Urban Water Management Plan
2020 Urban Water Management Plan
Fifth Year
Fourth Year
Third Year
Second Year
First Year
First Year
Second Year
Third Year
Fourth Year
Fifth Year
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For a more detailed description of the Water Reliability Assessment, refer to Attachments A-C.
17 outlining the UAC’s concerns regarding the Plan’s framework. The
upcoming draft 2025 UWMP documents the completion of the One Water Plan and summarizes
its findings related to recycled water projects. The draft 2025 UWMP will not identify the Phase
3 Expansion Project as a potential recycled water use because it was not included in the One
Water Plan’s portfolio evaluation due to high unit costs and comparatively lower yield relative
to other recycled water options.
FISCAL/RESOURCE IMPACT
17 Staff Report 2509-5258:
https://recordsportal.paloalto.gov/WebLink/DocView.aspx?id=83667&dbid=0&repo=PaloAlto
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No fiscal impact.
STAKEHOLDER ENGAGEMENT
th, 2026, followed by a presentation to City
Council on June 8th, 2026.
ENVIRONMENTAL REVIEW
ATTACHMENTS
AUTHOR/TITLE:
155 Bovet Road, Suite 650 ⚫ San Mateo, CA 94402 ⚫ ph 650 349 3000 ⚫ fx 650 349 8395 ⚫ www.bawsca.org
March 11, 2026
TO: BAWSCA Member Agencies
FROM: Danielle McPherson, Senior Water Resources Specialist
Tom Francis, Water Resources Manager
SUBJECT: San Francisco Regional Water System Supply Reliability for 2025 Urban
Water Management Plans
On March 11, 2026, the San Francisco Public Utilities Commission (SFPUC) provided a
letter with analysis on the Regional Water System (RWS) supply reliability for use in
your 2025 Urban Water Management Plans (UWMPs). This memorandum transmits
that letter (Attachment A) and provides additional context regarding individual agency
cutbacks outlined in Attachment B.
Regulatory and Demand Scenarios
To account for the ongoing uncertainty surrounding the State Water Resources Control
Board’s Bay-Delta Plan Amendment, the SFPUC modeled water supply reliability under
two regulatory scenarios and two demand scenarios:
• Regulatory Scenarios:
1. With implementation of the Bay-Delta Plan Amendment.
2. Without implementation of the Bay-Delta Plan Amendment.
• Demand Scenarios:
1. Projected SFPUC retail demand and Wholesale Customer purchases for
2030-2050.
2. Projected SFPUC retail demand for 2050 and the Wholesale Customer
Supply Assurance of 184 MGD.
Key Findings and Impacts on Allocation
Attachment B provides specific cutbacks for each agency based on Demand Scenario 1
(projected RWS demand). Please note the following critical impacts on how these
shortages are managed:
• Extreme Shortages Under Bay-Delta Implementation: Under the "With Bay-
Delta Plan" scenario, system-wide cutbacks exceed the SFPUC’s Level of
Service Goal to limit system-wide cutbacks to 20% or less. In these instances,
the Water Supply Agreement (WSA) allows for negotiated allocations between
March 11, 2026
Page 2 of 2
retail and Wholesale Customers collectively. In the absence of a negotiated
agreement, SFPUC has applied the Tier 1 split for a system-wide cutback up to
20%.
• Application of the Tier 2 Plan: The Tier 2 Drought Response Implementation
Plan only applies during system-wide shortages of 20% or less. Because the
"With Bay-Delta Plan" scenario results in wholesale cutbacks ranging from 31%
to 48%, the Tier 2 Plan cannot be applied.
• BAWSCA Recommendation: In the absence of a negotiated approach for
allocating RWS supply among the Wholesale Customers during shortages
exceeding 20%, BAWSCA suggests that agencies apply these cutbacks equally
across all agencies for their 2025 UWMPs.
• "Without Bay-Delta" Scenario: The SFPUC analyses do not anticipate any
cutbacks during the required five-year drought sequence under the "Without Bay-
Delta Plan" scenario.
Guidance for 2025 UWMP Reporting
For the 2020 UWMPs, most member agencies utilized the "With Bay-Delta Plan"
scenario for their standard tables and included the "Without Bay -Delta Plan" scenario in
supplemental tables or appendices. BAWSCA understands that the SFPUC intends to
follow this same approach for its own 2025 UWMP.
Note on Future Modeling (HRL Program)
While the SFPUC previously indicated it would model the Tuolumne River Healthy
Rivers and Landscapes Program (HRL), they have not provided that modeling at this
time due to significant implementation uncertainties.
Enclosed: Attachment A – 2025 UWMP Supply Reliability Letter_2026-03-11
Attachment B – 2025 UWMP Wholesale Customer Dry Year Allocations
cc: Tom Smegal
Allison Schutte
Services of the San Francisco Public Utilities Commission
OUR MISSION: To provide our customers with high-quality, efficient, and reliable water, power and sewer
services in a manner that values environmental and community interests and sustains the resources entrusted
to our care.
525 Golden Gate Ave
San Francisco, CA 94102
(415) 554-3155
sfpuc.gov
March 11, 2026
Danielle McPherson
Senior Water Resources Specialist
Bay Area Water Supply and Conservation Agency
155 Bovet Road, Suite 650
San Mateo, CA 94402
Dear Ms. McPherson,
This letter contains the supply reliability of the San Francisco Public Utilities
Commission (SFPUC) Regional Water System (RWS) that the SFPUC has
prepared for the 2025 Urban Water Management Plan (UWMP), which the
Wholesale Customers may also use in their respective 2025 UWMPs. The
SFPUC has assessed the RWS’s supply reliability under the following planning
scenarios:
1. Projected supply reliability for years 2030 through 2050, assuming total
demand is equivalent to the sum of the projected retail and wholesale
demands on the RWS, which includes Wholesale Customer purchase
projections provided to the SFPUC by BAWSCA on March 4, 2026
(refer to Table 1 below).
2. Projected supply reliability for 2050, assuming total demand is
equivalent to the sum of the projected retail demands on the RWS and
the Wholesale Customers’ Supply Assurance of 184 MGD.
3. Under each of the above demand conditions, projected supply reliability
for the following scenarios: (a) with implementation of the 2018
amendments to the Bay-Delta Water Quality Control Plan (Bay-Delta
Plan Amendment) and (b) without implementation of the Bay-Delta Plan
Amendment.
2025 UWMP Supply Reliability Memo
March 11, 2026
Page 2 of 14
Table 1. Retail and Wholesale RWS Demand Assumptions Used for Supply
Reliability Modeling (MGD)
20251 2030 2035 2040 2045 2050
Retail 61.1 62.7 61.2 61.9 64.0 66.7
Wholesale2 130.1 133.9 136.3 140.6 144.1 148.4
1 2025 demands are from the FY 2024-25 Table J-1 water use calculations, prepared
pursuant to the Water Supply Agreement between the SFPUC and the Wholesale
Customers.
2 2030 through 2050 Wholesale Customer purchase projections were provided to the
SFPUC by BAWSCA on March 4, 2026, and include demands for the cities of San
Jose and Santa Clara.
The total amount of water the SFPUC can deliver to the Retail and Wholesale
Customers from the RWS depends on several factors, including (1) the amount
of water that is available to the SFPUC from natural runoff, (2) the amount of
water in reservoir storage, and (3) the amount of water that the SFPUC
releases from the RWS for purposes other than customer deliveries (e.g.,
instream flow releases below RWS reservoirs). For planning purposes, the
SFPUC “average year” or “normal year” is based on historical hydrology under
conditions that allow the RWS reservoirs to be filled over the course of the
snowmelt season, allowing full deliveries to customers. For “dry-year” supply
scenarios, the SFPUC plans its water deliveries using a water-supply planning
methodology with reference to a simulated 8.5-year design drought.
In each demand scenario for 2030 through 2050, the SFPUC estimated RWS
deliveries using the standard SFPUC procedure, which includes adding
increased levels of rationing as needed in dry years to balance the demands on
the RWS with available water supply. The five consecutive dry-year sequence
shown in the tables below represent years 2 through 6 of the design drought.
The SFPUC chose this sequence because year 2 is the first year in which
system-wide water use reductions could take effect, as the design drought
sequence generally begins year 1 with full reservoirs. All simulations that the
SFPUC has prepared for its 2025 UWMP have increased levels of rationing in
the final years of the design drought sequence. The SFPUC has presented the
results in the standardized format prescribed by DWR.
Assumptions about the status of the dry-year water supply projects included in
the SFPUC’s Water System Improvement Program (WSIP) are provided below
in Table 2 titled “WSIP Project Assumptions for RWS Supply Modeling.” The
table reflects instream flow requirements at San Mateo and Alameda Creeks,
2025 UWMP Supply Reliability Memo
March 11, 2026
Page 3 of 14
as described in the UWMP “common language” that the SFPUC provided to
BAWSCA and the Wholesale Customers separately from this letter.
The SFPUC utilized the Water Shortage Allocation Plan (WSAP) that is
incorporated in the Water Supply Agreement between the SFPUC and the
Wholesale Customers to allocate the RWS supply available during dry years
between the Retail Customers and the Wholesale Customers in the 2025
UWMP supply reliability analysis. The WSAP, also known as the Tier 1 Plan,
defines the method for allocating between the Retail Customers collectively
and Wholesale Customers collectively the available RWS supplies during
system-wide shortages. The SFPUC and the Wholesale Customers most
recently amended the WSAP in 2025. Also in 2025, the Wholesale Customers
adopted an updated Tier 2 Plan, which allocates the collective Wholesale
Customers’ share of available RWS supplies from the Tier 1 Plan among each
of the 26 Wholesale Customers. The WSAP addresses shortages that require
a system-wide reduction in water use of 20% or less, consistent with the
SFPUC’s Level of Service Goal. For any shortage scenario requiring a system-
wide reduction in water use above 20% in the supply reliability analysis, the
SFPUC applied the Tier 1 Plan’s allocation of supplies between the Retail
Customers and Wholesale Customers for a shortage requiring a system-wide
reduction in water use of 16-20%.
Because of the uncertainty surrounding implementation of the Bay-Delta Plan
Amendment, the RWS supply reliability assessment evaluates two future
supply scenarios: (1) with implementation of the Bay-Delta Plan Amendment,
and (2) without implementation of the Bay-Delta Plan Amendment. It is
unknown when implementation may begin on the Bay-Delta Plan Amendment;
for the purposes of the 2025 UWMP analysis, the SFPUC included it beginning
in the 2030 modeling scenarios (see Tables 4a-4g and 6).
The SFPUC incorporated additional modeling assumptions in the 2025 UWMP
analysis regarding the State Water Resources Control Board curtailments and
assumptions regarding agreements with Turlock and Modesto Irrigation
Districts pertaining to instream flow obligations.
1. During the last two drought periods, 2013-2016 and 2021-2023, the
State Water Resources Control Board implemented curtailments
through emergency regulations and curtailment orders that attempted to
limit diversions from Central Valley watersheds including the Tuolumne
River at certain times. Due to the uncertain legality of the State Water
Resources Control Board’s curtailment actions as well as the
2025 UWMP Supply Reliability Memo
March 11, 2026
Page 4 of 14
uncertainties regarding any potential future curtailment actions against
San Francisco, the SFPUC’s RWS supply reliability analyses do not
assume curtailments are in effect.
2. Through a 1966 agreement with the Modesto and Turlock Irrigation
Districts (Districts), who are more senior downstream appropriative
water rights holders on the Tuolumne River, San Francisco may
become responsible for up to approximately 51.7% of any flow releases
the Federal Energy Regulatory Commission (FERC) may require
through issuance of a new license for the Districts’ Don Pedro
Hydropower Project. The exact flow contribution for which San
Francisco may become responsible is highly uncertain and may depend
on multiple currently unknown factors, including an anticipated
Endangered Species Act biological opinion from the National Marine
Fisheries Service and a Clean Water Act section 401 water quality
certification from the State Water Resources Control Board. San
Francisco’s potential responsibility for FERC-ordered flows may further
depend on San Francisco’s ability to enter into a new or extended
agreement with the Districts to offset a portion of San Francisco’s flow
contributions in exchange for payment. Due to the high levels of
uncertainty surrounding the Districts’ FERC-relicensing process, as well
as the unknown timing for license issuance, the SFPUC’s RWS water
supply reliability analyses do not assume additional water supply losses
from any potential new FERC-ordered flow releases.
3. The simulation of the Bay-Delta Plan Amendment scenario assumes
that a 1996 agreement between San Francisco and the Districts (the
Side Agreement), which allows San Francisco to pay the Districts in lieu
of contributing a portion of current FERC-ordered flow releases,
remains in effect, and that the San Francisco share of flows in excess of
and not covered by the Side Agreement is approximately 51.7%. These
assumptions were made for the purpose of completing the modeling for
the UWMP update, and they do not represent a commitment by San
Francisco or the Districts to any future agreement or of San Francisco
accepting responsibility for any future FERC-ordered flow releases.
Based on current projected demands, supply modeling for the two future supply
scenarios shows significantly different supply reliability projections for the
RWS:
• With implementation of the Bay-Delta Plan Amendment: Under this
scenario, using the demand assumptions shown in Table 1, RWS
supplies are expected to range from full availability in an average year
2025 UWMP Supply Reliability Memo
March 11, 2026
Page 5 of 14
(100%) to as low as 57% in multiple dry years when compared to water
supplies in an average year. In other words, RWS supplies could be
reduced by up to 43% in a multi-year drought. See Tables 4a-4g and 6.
• Without implementation of the Bay-Delta Plan Amendment: Under this
scenario, using demand assumptions shown in Table 1, there are no
anticipated shortages of RWS supplies. See Tables 5a-5g and 7.
Table 8 below provides the Wholesale Customer purchase projections and
Wholesale Customer allocation of RWS supply for the five-year drought risk
assessment from 2026 to 2030. The supply projections for 2026 to 2030 are
based on a linear growth from 2025 to 2030 levels of demand as calculated by
BAWSCA. This table does not assume implementation of the Bay-Delta Plan
Amendment because the start of implementation remains uncertain.
In the forthcoming 2025 UWMP, the SFPUC acknowledges that it has a Level
of Service objective to meet an average annual water demand of 265 MGD
from the SFPUC watersheds for Retail and Wholesale Customers during non-
drought years, as well as a contractual obligation to supply 184 MGD to the
Wholesale Customers, subject to reduction under certain conditions. The
SFPUC will, accordingly, include the results of modeling based on a Wholesale
Customer demand of 184 MGD to facilitate planning that supports meeting this
Level of Service objective and its contractual obligations. The results of this
modeling will be in an appendix to the 2025 UWMP prepared by the SFPUC.
The RWS supply projections shown in the tables below are more accurately
characterized as supplies that will be used to meet projected Retail and
Wholesale Customer demands.
It is our understanding that you will pass this information on to the Wholesale
Customers. If you have any questions or need additional information, please do
not hesitate to contact Jennifer Lee at jenlee@sfwater.org or (415) 551-4563.
Sincerely,
Steven R. Ritchie
Assistant General Manager, Water Enterprise
2025 UWMP Supply Reliability Memo
March 11, 2026
Page 6 of 14
Table 2: WSIP Project Assumptions for RWS Supply Modeling
Projects Base Year 2025 Beyond Beyond
Lower Crystal Springs
Dam Improvements not fully restored not fully restored not fully restored
Regional Groundwater
Storage and Recovery
(GSR) Project
filled at spring 2020
level of 43,000 AF; GSR
recovery rate of
5.2 MGDa
GSR account fully filled;
GSR recovery rate of
5.2 MGDa
GSR account fully filled;
GSR recovery rate of
6.2 MGDa
Recapture Project Project not built operating operating
Dry-Year Transfers Not in effect Not in effect Not in effect
a. The GSR Project was intended to provide 7.2 MGD over 7.5 years, however current limitations on
the number of wells available will result in deliveries less than 7.2 MGD over 7.5 years.
Table 3: Projected Total Regional Water System Supply Utilized and Portion of Regional
Water System Supply Utilized by Wholesale Customers in Normal Years [For Table 6-9]:
RWS Supply 2030 2035 2040 2045 2050
RWS Supply Utilized (MGD) 196.6 197.5 202.5 208.1 215.1
Customersa (MGD) 133.9 136.3 140.6 144.1 148.4
a. RWS supply utilized by Wholesale Customers from 2030 through 2050 is equivalent to Wholesale
Customer purchase projections provided to the SFPUC by BAWSCA on March 4, 2026, and
includes demands for the cities of San Jose and Santa Clara.
2025 UWMP Supply Reliability Memo
March 11, 2026
Page 7 of 14
Basis of Water Supply Data: With Implementation of the Bay-Delta
Plan Amendment
Table 4a: Basis of Water Supply Data [For Table 7-1], Base Year 2030, With Bay-Delta
Plan Amendment
Year Type Base
Year
Volume
Available
(MGD)
% of
Average
Supply
Volume
Available
(MGD)
Notes on Calculation of
Wholesale Allocation of
RWS
Average year 2030 196.6 100%133.9
Single dry year 2030 147.5 75% 92.2
At shortages 20% or greater,
wholesale allocation is
assumed to be 62.5% and
retail allocation is 37.5%.
Table 4b: Basis of Water Supply Data [For Table 7-1], Base Year 2035, With Bay-Delta
Plan Amendment
Year Type Base
Year
Volume
Available
(MGD)
% of
Average
Supply
Volume
Available
(MGD)
Notes on Calculation of
Wholesale Allocation of
RWS
Average year 2035 197.5 100% 136.3
Single dry year 2035 146.2 74% 91.3
greater, wholesale
allocation is assumed to be
62.5% and retail allocation
is 37.5%.
2025 UWMP Supply Reliability Memo
March 11, 2026
Page 8 of 14
Table 4c: Basis of Water Supply Data [For Table 7-1], Base Year 2040, With Bay-Delta
Plan Amendment
Year Type Base
Year
Volume
Available
(MGD)
% of
Average
Supply
Volume
Available
(MGD)
Notes on Calculation of
Wholesale Allocation of
RWS
Average year 2040 202.5 100% 140.6
Single dry year 2040 145.8 72% 91.1
greater, wholesale
allocation is assumed to be
62.5% and retail allocation
is 37.5%.
Table 4d: Basis of Water Supply Data [For Table 7-1], Base Year 2045, With Bay-Delta
Plan Amendment
Year Type Base
Year
Volume
Available
% of
Average
Supply
Volume
Available
Notes on Calculation of
Wholesale Allocation of
RWS
Average year 2045 208.1 100% 144.1
Single dry year 2045 145.7 70% 91.0
greater, wholesale
allocation is assumed to be
62.5% and retail allocation
is 37.5%.
2025 UWMP Supply Reliability Memo
March 11, 2026
Page 9 of 14
Table 4e: Basis of Water Supply Data [For Table 7-1], Base Year 2050, With Bay-Delta
Plan Amendment
Year Type Base
Year
Volume
Available
(MGD)
% of
Average
Supply
Volume
Available
(MGD)
Notes on Calculation of
Wholesale Allocation of
RWS
Average year 2050 215.1 100% 148.4
Single dry year 2050 146.2 68% 91.4
greater, wholesale
allocation is assumed to be
62.5% and retail allocation
is 37.5%.
Table 4f: Basis of Water Supply Data [For Table 7-1], Base Year 2050, With Bay-Delta Plan
Amendment and Wholesale Demands at 184 MGD Supply Assurance
Year Type Base
Year
Volume
Available
(MGD)
% of
Average
Supply
Volume
Available
(MGD)
Notes on Calculation of
Wholesale Allocation of
RWS
Average year 2050 250.7 100% 184.0
Single dry year 2050 145.4 58% 90.9
greater, wholesale
allocation is assumed to be
62.5% and retail allocation
is 37.5%.
2025 UWMP Supply Reliability Memo
March 11, 2026
Page 10 of 14
Table 4g: Projected RWS Supply Availability [Alternative to Table 7-1], Years 2030-2050,
With Bay-Delta Plan Amendment
Year Type 2030 2035 2040 2045 2050 MGD Supply
Assurance)
Average year 100% 100% 100% 100% 100% 100%
Single dry year 75% 74% 72% 70% 68% 58%
Consecutive 1st dry year 75% 74% 72% 70% 68% 58%
Consecutive 2nd dry year 63% 63% 61% 59% 57% 48%
Consecutive 3rd dry year 63% 63% 61% 59% 57% 48%
Consecutive 4th dry year 63% 63% 61% 59% 57% 48%
Consecutive 5th dry year 63% 63% 61% 59% 57% 48%
2025 UWMP Supply Reliability Memo
March 11, 2026
Page 11 of 14
Basis of Water Supply Data: Without Implementation of the Bay-Delta
Plan Amendment
Table 5a: Basis of Water Supply Data [For Table 7-1], Base Year 2030, Without Bay-Delta
Plan Amendment
Year Type Base
Year
Volume
Available
(MGD)
% of
Average
Supply
Volume
Available
(MGD)
Notes on Calculation of
Wholesale Allocation of
RWS
Average year 2030 196.6 100% 133.9
Single dry year 2030 196.6 100% 133.9
Consecutive 1st dry year 2030 196.6 100% 133.9
Consecutive 2nd dry year 2030 196.6 100% 133.9
Consecutive 3rd dry year 2030 196.6 100% 133.9
Consecutive 4th dry year 2030 196.6 100% 133.9
Consecutive 5th dry year 2030 196.6 100% 133.9
Table 5b: Basis of Water Supply Data [For Table 7-1], Base Year 2035, Without Bay-Delta
Plan Amendment
Year Type Base
Year
Volume
Available
(MGD)
% of
Average
Supply
Volume
Available
(MGD)
Notes on Calculation of
Wholesale Allocation of
RWS
Average year 2035 197.5 100% 136.3
Single dry year 2035 197.5 100% 136.3
Consecutive 1st dry year 2035 197.5 100% 136.3
Consecutive 2nd dry year 2035 197.5 100% 136.3
Consecutive 3rd dry year 2035 197.5 100% 136.3
Consecutive 4th dry year 2035 197.5 100% 136.3
Consecutive 5th dry year 2035 197.5 100% 136.3
2025 UWMP Supply Reliability Memo
March 11, 2026
Page 12 of 14
Table 5c: Basis of Water Supply Data [For Table 7-1], Base Year 2040, Without Bay-Delta
Plan Amendment
Year Type Base
Year
Volume
Available
(MGD)
% of
Average
Supply
Volume
Available
(MGD)
Notes on Calculation of
Wholesale Allocation of
RWS
Average year 2040 202.5 100% 140.6
Single dry year 2040 202.5 100% 140.6
Consecutive 1st dry year 2040 202.5 100% 140.6
Consecutive 2nd dry year 2040 202.5 100% 140.6
Consecutive 3rd dry year 2040 202.5 100% 140.6
Consecutive 4th dry year 2040 202.5 100% 140.6
Consecutive 5th dry year 2040 202.5 100% 140.6
Table 5d: Basis of Water Supply Data [For Table 7-1], Base Year 2045, Without Bay-Delta
Plan Amendment
Year Type Base
Year
Volume
Available
(MGD)
% of
Average
Supply
Volume
Available
(MGD)
Notes on Calculation of
Wholesale Allocation of
RWS
Average year 2045 208.1 100% 144.1
Single dry year 2045 208.1 100% 144.1
Consecutive 1st dry year 2045 208.1 100% 144.1
Consecutive 2nd dry year 2045 208.1 100% 144.1
Consecutive 3rd dry year 2045 208.1 100% 144.1
Consecutive 4th dry year 2045 208.1 100% 144.1
Consecutive 5th dry year 2045 208.1 100% 144.1
Table 5e: Basis of Water Supply Data [For Table 7-1], Base Year 2050, Without Bay-Delta
Plan Amendment
Year Type Base
Year
Volume
Available
% of
Average
Supply
Volume
Available
Notes on Calculation of
Wholesale Allocation of
RWS
Average year 2050 215.1 100% 148.4
Single dry year 2050 215.1 100% 148.4
Consecutive 1st dry year 2050 215.1 100% 148.4
Consecutive 2nd dry year 2050 215.1 100% 148.4
Consecutive 3rd dry year 2050 215.1 100% 148.4
Consecutive 4th dry year 2050 215.1 100% 148.4
Consecutive 5th dry year 2050 215.1 100% 148.4
2025 UWMP Supply Reliability Memo
March 11, 2026
Page 13 of 14
Table 5f: Basis of Water Supply Data [For Table 7-1], Base Year 2050, Without Bay-Delta
Plan Amendment and Wholesale Demands at 184 MGD Supply Assurance
Year Type Base
Year
Volume
Available
% of
Average
Supply
Volume
Available
Notes on Calculation of
Wholesale Allocation of
RWS
Average year 2050 250.7 100% 184.0
Single dry year 2050 225.6 90% 158.9
allocation is 64% (144.4 MGD)
and retail allocation is 36%
(81.2 MGD). Retail allocations
above 66.7 MGD are re-
allocated to Wholesale
Customers, per the Water
Supply Agreement. Therefore,
14.5 MGD is added to
wholesale allocation, bringing
it to 158.9 MGD.
Same as above.
Table 5g: Projected RWS Supply [Alternative to Table 7-1], Years 2030-2050, Without Bay-
Delta Plan Amendment
Year Type 2030 2035 2040 2045 2050 MGD Supply
Assurance)
Average year 100% 100% 100% 100% 100% 100%
Single dry year 100% 100% 100% 100% 100% 90%
Consecutive 1st dry year 100% 100% 100% 100% 100% 90%
Consecutive 2nd dry year 100% 100% 100% 100% 100% 90%
Consecutive 3rd dry year 100% 100% 100% 100% 100% 90%
Consecutive 4th dry year 100% 100% 100% 100% 100% 90%
Consecutive 5th dry year 100% 100% 100% 100% 100% 90%
2025 UWMP Supply Reliability Memo
March 11, 2026
Page 14 of 14
Supply Projections for Consecutive Five Dry Year Sequences
Table 6: Projected Multiple Dry Years RWS Wholesale Allocation [For Table 7-4], With
Bay-Delta Plan Amendment
2030 2035 2040 2045 2050 Supply Assurance)
First year 92.2 91.3 91.1 91.0 91.4 90.9
Second year 77.4 77.8 77.2 76.7 76.6 75.2
Third year 77.4 77.8 77.2 76.7 76.6 75.2
Fourth year 77.4 77.8 77.2 76.7 76.6 75.2
Fifth year 77.4 77.8 77.2 76.7 76.6 75.2
Table 7: Projected Multiple Dry Years RWS Wholesale Allocation [For Table 7-4], Without
Bay-Delta Plan Amendment
2030 2035 2040 2045 2050 Supply Assurance)
First year 133.9 136.3 140.6 144.1 148.4 158.9
Second year 133.9 136.3 140.6 144.1 148.4 158.9
Third year 133.9 136.3 140.6 144.1 148.4 158.9
Fourth year 133.9 136.3 140.6 144.1 148.4 158.9
Fifth year 133.9 136.3 140.6 144.1 148.4 158.9
Table 8: Projected RWS Supply for 5-Year Drought Risk Assessment [For Table 7-5]
Year 2026 2027 2028 2029 2030
Wholesale Purchase
Projectionsa (MGD) 130.9 131.6 132.4 133.2 133.9
Wholesale Customersb (MGD) 130.9 131.6 132.4 133.2 133.9
a. Wholesale Purchase Projections for 2026-2030 assume a linear growth between 2025 actual
demands and 2030 projections, as calculated by BAWSCA.
b. This table does not assume implementation of the Bay-Delta Plan Amendment because the start
of implementation remains uncertain.
Attachment B: 2025 UWMP Wholesale Customer Dry Year Allocations
Basis for SFPUC's Water Supply Reliability Modeling
Actual (2025) and Projected (2030-2050) RWS Purchases
Agency ISG 20251 2030 2035 2040 2045 2050
Alameda CWD 13.76 10.08 11.25 11.56 12.00 12.45 13.76
Brisbane / GVMID 0.98 0.68 0.94 0.95 0.97 0.97 0.97
Burlingame 5.23 3.23 3.92 3.99 4.15 4.30 4.44
Coastside CWD 2.18 1.01 1.17 1.16 1.16 1.16 1.16
CWS Total 35.68 29.50 27.04 26.89 26.93 26.80 26.89
Daly City 4.29 3.55 4.29 4.29 4.29 4.29 4.29
East Palo Alto 3.46 1.72 1.19 1.19 1.19 1.18 1.19
Estero MID 5.90 3.78 3.90 3.92 3.93 3.91 3.90
Hayward 22.09 13.66 14.74 15.66 16.82 18.14 19.71
Hillsborough 4.09 2.32 2.09 2.08 2.09 2.11 2.12
Menlo Park 4.46 2.72 2.58 2.64 2.71 2.76 2.83
Mid-Peninsula WD 3.89 2.34 2.82 2.97 3.18 3.39 3.43
Millbrae 3.15 1.81 1.91 1.99 2.09 2.18 2.29
Milpitas 9.23 4.68 5.30 5.35 5.41 5.46 5.52
Mountain View 12.46 7.69 7.87 8.12 8.59 9.04 9.55
North Coast CWD 3.84 2.58 2.23 2.29 2.37 2.36 2.36
Palo Alto 16.58 9.31 8.30 8.20 8.15 8.15 8.18
Purissima Hills WD 1.63 1.51 1.36 1.35 1.36 1.36 1.37
Redwood City 10.93 7.43 6.84 6.54 6.73 6.91 7.09
San Bruno 3.25 1.03 1.85 2.27 2.68 2.68 2.68
San Jose 3.99 4.50 4.50 4.50 4.50 4.50
Santa Clara 2.91 4.50 4.50 4.50 4.50 4.50
Stanford 3.03 1.59 1.77 1.96 2.02 2.07 2.13
Sunnyvale 12.58 10.28 10.72 11.15 11.92 12.58 12.58
Westborough WD 1.32 0.70 0.82 0.80 0.84 0.88 0.91
Total 184.00 130.1 133.9 136.3 140.6 144.1 148.3
1 Source: FY 2024-25 J-Table
Attachment B: 2025 UWMP Wholesale Customer Dry Year Allocations
Basis for SFPUC's Water Supply Reliability Modeling
Actual (2025) and Projected (2026-2030) RWS Purchases
Agency 2025 2026 2027 2028 2029 2030
Alameda CWD 10.08 10.32 10.55 10.78 11.02 11.25
Brisbane / GVMID 0.68 0.73 0.78 0.83 0.89 0.94
Burlingame 3.23 3.36 3.50 3.64 3.78 3.92
Coastside CWD 1.01 1.05 1.08 1.11 1.14 1.17
CWS Total 29.50 29.00 28.51 28.02 27.53 27.04
Daly City 3.55 3.70 3.85 4.00 4.14 4.29
East Palo Alto 1.72 1.62 1.51 1.40 1.30 1.19
Estero MID 3.78 3.80 3.83 3.85 3.88 3.90
Hayward 13.66 13.87 14.09 14.31 14.53 14.74
Hillsborough 2.32 2.27 2.23 2.18 2.14 2.09
Menlo Park 2.72 2.69 2.67 2.64 2.61 2.58
Mid-Peninsula WD 2.34 2.44 2.53 2.63 2.73 2.82
Millbrae 1.81 1.83 1.85 1.87 1.89 1.91
Milpitas 4.68 4.80 4.93 5.05 5.18 5.30
Mountain View 7.69 7.73 7.76 7.80 7.83 7.87
North Coast CWD 2.58 2.51 2.44 2.37 2.30 2.23
Palo Alto 9.31 9.11 8.91 8.71 8.50 8.30
Purissima Hills WD 1.51 1.48 1.45 1.42 1.39 1.36
Redwood City 7.43 7.32 7.20 7.08 6.96 6.84
San Bruno 1.03 1.20 1.36 1.52 1.69 1.85
San Jose 3.99 4.09 4.20 4.30 4.40 4.50
Santa Clara 2.91 3.23 3.54 3.86 4.18 4.50
Stanford 1.59 1.62 1.66 1.70 1.73 1.77
Sunnyvale 10.28 10.37 10.46 10.55 10.63 10.72
Westborough WD 0.70 0.72 0.75 0.77 0.80 0.82
Total 130.1 130.9 131.6 132.4 133.2 133.9
Attachment B: 2025 UWMP Wholesale Customer Dry Year Allocations
For UWMP Tables 7-1 through Table 7-4
2025
With BDP
Basis of Water Supply Data
2026 2027 2028 2029 2030
130.12 130.88 131.64 132.40 133.16
130.12 130.88 131.64 132.40 133.16
0%0%0%0%0%
Projected Supply by Year Type Projected Supply by Year Type
Agency
2025 RWS
Purchases 2026 2027 2028 2029 2030
Alameda CWD 10.08 10.08 11.25 11.56 12.00 12.45
Brisbane / GVMID 0.68 0.68 0.68 0.68 0.68 0.68
Burlingame 3.23 3.23 3.23 3.23 3.23 3.23
Coastside CWD 1.01 1.01 1.01 1.01 1.01 1.01
CWS Total 29.50 29.50 29.50 29.50 29.50 29.50
Daly City 3.55 3.55 3.55 3.55 3.55 3.55
East Palo Alto 1.72 1.72 1.72 1.72 1.72 1.72
Estero MID 3.78 3.78 3.78 3.78 3.78 3.78
Hayward 13.66 13.66 13.66 13.66 13.66 13.66
Hillsborough 2.32 2.32 2.32 2.32 2.32 2.32
Menlo Park 2.72 2.72 2.72 2.72 2.72 2.72
Mid-Peninsula WD 2.34 2.34 2.34 2.34 2.34 2.34
Millbrae 1.81 1.81 1.81 1.81 1.81 1.81
Milpitas 4.68 4.68 4.68 4.68 4.68 4.68
Mountain View 7.69 7.69 7.69 7.69 7.69 7.69
North Coast CWD 2.58 2.58 2.58 2.58 2.58 2.58
Palo Alto 9.31 9.31 9.31 9.31 9.31 9.31
Purissima Hills WD 1.51 1.51 1.51 1.51 1.51 1.51
Redwood City 7.43 7.43 7.43 7.43 7.43 7.43
San Bruno 1.03 1.03 1.03 1.03 1.03 1.03
San Jose 3.99 3.99 3.99 3.99 3.99 3.99
Santa Clara 2.91 2.91 2.91 2.91 2.91 2.91
Stanford 1.59 1.59 1.59 1.59 1.59 1.59
Sunnyvale 10.28 10.28 10.28 10.28 10.28 10.28
Westborough WD 0.70 0.70 0.70 0.70 0.70 0.70
Total 130.12 130.12 131.28 131.59 132.03 132.48
Percent Cutback
Wholesale RWS Demand
Wholesale RWS Supply
Base Year
Scenario
Consecutive Dry Year
Attachment B: 2025 UWMP Wholesale Customer Dry Year Allocations
For UWMP Tables 7-1 through Table 7-4
2030
With BDP
Basis of Water Supply Data
1st/Single 2nd 3rd 4th 5th
133.9 133.9 133.9 133.9 133.9
92.2 77.4 77.4 77.4 77.4
31%42%42%42%42%
Projected Supply by Year Type Projected Supply by Year Type
Agency
2030 Proj.
RWS
1st/Single
Dry Year
2nd Dry
Year
3rd Dry
Year
4th Dry
Year
5th Dry
Year
Alameda CWD 11.25 7.75 6.50 6.50 6.50 6.50
Brisbane / GVMID 0.94 0.65 0.54 0.54 0.54 0.54
Burlingame 3.92 2.70 2.27 2.27 2.27 2.27
Coastside CWD 1.17 0.81 0.68 0.68 0.68 0.68
CWS Total 27.04 18.61 15.63 15.63 15.63 15.63
Daly City 4.29 2.95 2.48 2.48 2.48 2.48
East Palo Alto 1.19 0.82 0.69 0.69 0.69 0.69
Estero MID 3.90 2.69 2.25 2.25 2.25 2.25
Hayward 14.74 10.15 8.52 8.52 8.52 8.52
Hillsborough 2.09 1.44 1.21 1.21 1.21 1.21
Menlo Park 2.58 1.78 1.49 1.49 1.49 1.49
Mid-Peninsula WD 2.82 1.94 1.63 1.63 1.63 1.63
Millbrae 1.91 1.31 1.10 1.10 1.10 1.10
Milpitas 5.30 3.65 3.06 3.06 3.06 3.06
Mountain View 7.87 5.42 4.55 4.55 4.55 4.55
North Coast CWD 2.23 1.54 1.29 1.29 1.29 1.29
Palo Alto 8.30 5.72 4.80 4.80 4.80 4.80
Purissima Hills WD 1.36 0.94 0.79 0.79 0.79 0.79
Redwood City 6.84 4.71 3.95 3.95 3.95 3.95
San Bruno 1.85 1.27 1.07 1.07 1.07 1.07
San Jose 4.50 3.10 2.60 2.60 2.60 2.60
Santa Clara 4.50 3.10 2.60 2.60 2.60 2.60
Stanford 1.77 1.22 1.02 1.02 1.02 1.02
Sunnyvale 10.72 7.38 6.20 6.20 6.20 6.20
Westborough WD 0.82 0.57 0.48 0.48 0.48 0.48
Total 133.92 92.2 77.4 77.4 77.4 77.4
Percent Cutback
Wholesale RWS Demand
Wholesale RWS Supply
Base Year
Scenario
Consecutive Dry Year
Attachment B: 2025 UWMP Wholesale Customer Dry Year Allocations
For UWMP Tables 7-1 through Table 7-4
2035
With BDP
Basis of Water Supply Data
1st/Single 2nd 3rd 4th 5th
136.32 136.32 136.32 136.32 136.32
91.3 77.8 77.8 77.8 77.8
33%43%43%43%43%
Projected Supply by Year Type Projected Supply by Year Type
Agency
2035 Proj.
RWS
1st/Single
Dry Year
2nd Dry
Year
3rd Dry
Year
4th Dry
Year
5th Dry
Year
Alameda CWD 11.56 7.74 6.60 6.60 6.60 6.60
Brisbane / GVMID 0.95 0.64 0.54 0.54 0.54 0.54
Burlingame 3.99 2.67 2.28 2.28 2.28 2.28
Coastside CWD 1.16 0.78 0.66 0.66 0.66 0.66
CWS Total 26.89 18.01 15.35 15.35 15.35 15.35
Daly City 4.29 2.87 2.45 2.45 2.45 2.45
East Palo Alto 1.19 0.80 0.68 0.68 0.68 0.68
Estero MID 3.92 2.63 2.24 2.24 2.24 2.24
Hayward 15.66 10.49 8.93 8.93 8.93 8.93
Hillsborough 2.08 1.39 1.19 1.19 1.19 1.19
Menlo Park 2.64 1.77 1.51 1.51 1.51 1.51
Mid-Peninsula WD 2.97 1.99 1.69 1.69 1.69 1.69
Millbrae 1.99 1.33 1.14 1.14 1.14 1.14
Milpitas 5.35 3.58 3.05 3.05 3.05 3.05
Mountain View 8.12 5.44 4.63 4.63 4.63 4.63
North Coast CWD 2.29 1.53 1.31 1.31 1.31 1.31
Palo Alto 8.20 5.49 4.68 4.68 4.68 4.68
Purissima Hills WD 1.35 0.90 0.77 0.77 0.77 0.77
Redwood City 6.54 4.38 3.73 3.73 3.73 3.73
San Bruno 2.27 1.52 1.30 1.30 1.30 1.30
San Jose 4.50 3.01 2.57 2.57 2.57 2.57
Santa Clara 4.50 3.01 2.57 2.57 2.57 2.57
Stanford 1.96 1.31 1.12 1.12 1.12 1.12
Sunnyvale 11.15 7.47 6.36 6.36 6.36 6.36
Westborough WD 0.80 0.54 0.46 0.46 0.46 0.46
Total 136.32 91.3 77.8 77.8 77.8 77.8
Percent Cutback
Base Year
Scenario
Consecutive Dry Year
Wholesale RWS Demand
Wholesale RWS Supply
Attachment B: 2025 UWMP Wholesale Customer Dry Year Allocations
For UWMP Tables 7-1 through Table 7-4
2040
With BDP
Basis of Water Supply Data
1st/Single 2nd 3rd 4th 5th
140.57 140.57 140.57 140.57 140.57
91.1 77.2 77.2 77.2 77.2
35%45%45%45%45%
Projected Supply by Year Type Projected Supply by Year Type
Agency
2040 Proj.
RWS
1st/Single
Dry Year
2nd Dry
Year
3rd Dry
Year
4th Dry
Year
5th Dry
Year
Alameda CWD 12.00 7.78 6.59 6.59 6.59 6.59
Brisbane / GVMID 0.97 0.63 0.53 0.53 0.53 0.53
Burlingame 4.15 2.69 2.28 2.28 2.28 2.28
Coastside CWD 1.16 0.75 0.64 0.64 0.64 0.64
CWS Total 26.93 17.45 14.79 14.79 14.79 14.79
Daly City 4.29 2.78 2.36 2.36 2.36 2.36
East Palo Alto 1.19 0.77 0.65 0.65 0.65 0.65
Estero MID 3.93 2.54 2.16 2.16 2.16 2.16
Hayward 16.82 10.90 9.24 9.24 9.24 9.24
Hillsborough 2.09 1.35 1.15 1.15 1.15 1.15
Menlo Park 2.71 1.75 1.49 1.49 1.49 1.49
Mid-Peninsula WD 3.18 2.06 1.75 1.75 1.75 1.75
Millbrae 2.09 1.35 1.15 1.15 1.15 1.15
Milpitas 5.41 3.51 2.97 2.97 2.97 2.97
Mountain View 8.59 5.57 4.72 4.72 4.72 4.72
North Coast CWD 2.37 1.53 1.30 1.30 1.30 1.30
Palo Alto 8.15 5.28 4.48 4.48 4.48 4.48
Purissima Hills WD 1.36 0.88 0.75 0.75 0.75 0.75
Redwood City 6.73 4.36 3.69 3.69 3.69 3.69
San Bruno 2.68 1.74 1.47 1.47 1.47 1.47
San Jose 4.50 2.92 2.47 2.47 2.47 2.47
Santa Clara 4.50 2.92 2.47 2.47 2.47 2.47
Stanford 2.02 1.31 1.11 1.11 1.11 1.11
Sunnyvale 11.92 7.73 6.55 6.55 6.55 6.55
Westborough WD 0.84 0.55 0.46 0.46 0.46 0.46
Total 140.57 91.1 77.2 77.2 77.2 77.2
Base Year
Scenario
Consecutive Dry Year
Wholesale RWS Demand
Wholesale RWS Supply
Percent Cutback
Attachment B: 2025 UWMP Wholesale Customer Dry Year Allocations
For UWMP Tables 7-1 through Table 7-4
2045
With BDP
Basis of Water Supply Data
1st/Single 2nd 3rd 4th 5th
144.11 144.11 144.11 144.11 144.11
91 76.7 76.7 76.7 76.7
37%47%47%47%47%
Projected Supply by Year Type Projected Supply by Year Type
Agency
2045 Proj.
RWS
1st/Single
Dry Year
2nd Dry
Year
3rd Dry
Year
4th Dry
Year
5th Dry
Year
Alameda CWD 12.45 7.86 6.63 6.63 6.63 6.63
Brisbane / GVMID 0.97 0.61 0.52 0.52 0.52 0.52
Burlingame 4.30 2.72 2.29 2.29 2.29 2.29
Coastside CWD 1.16 0.73 0.62 0.62 0.62 0.62
CWS Total 26.80 16.92 14.26 14.26 14.26 14.26
Daly City 4.29 2.71 2.28 2.28 2.28 2.28
East Palo Alto 1.18 0.75 0.63 0.63 0.63 0.63
Estero MID 3.91 2.47 2.08 2.08 2.08 2.08
Hayward 18.14 11.45 9.65 9.65 9.65 9.65
Hillsborough 2.11 1.33 1.12 1.12 1.12 1.12
Menlo Park 2.76 1.75 1.47 1.47 1.47 1.47
Mid-Peninsula WD 3.39 2.14 1.80 1.80 1.80 1.80
Millbrae 2.18 1.38 1.16 1.16 1.16 1.16
Milpitas 5.46 3.45 2.91 2.91 2.91 2.91
Mountain View 9.04 5.71 4.81 4.81 4.81 4.81
North Coast CWD 2.36 1.49 1.26 1.26 1.26 1.26
Palo Alto 8.15 5.14 4.34 4.34 4.34 4.34
Purissima Hills WD 1.36 0.86 0.72 0.72 0.72 0.72
Redwood City 6.91 4.36 3.68 3.68 3.68 3.68
San Bruno 2.68 1.69 1.43 1.43 1.43 1.43
San Jose 4.50 2.84 2.40 2.40 2.40 2.40
Santa Clara 4.50 2.84 2.40 2.40 2.40 2.40
Stanford 2.07 1.31 1.10 1.10 1.10 1.10
Sunnyvale 12.58 7.94 6.70 6.70 6.70 6.70
Westborough WD 0.88 0.55 0.47 0.47 0.47 0.47
Total 144.11 91.0 76.7 76.7 76.7 76.7
Percent Cutback
Base Year
Scenario
Consecutive Dry Year
Wholesale RWS Demand
Wholesale RWS Supply
Attachment B: 2025 UWMP Wholesale Customer Dry Year Allocations
For UWMP Tables 7-1 through Table 7-4
2050
With BDP
Basis of Water Supply Data
1st/Single 2nd 3rd 4th 5th
148.35 148.35 148.35 148.35 148.35
91.4 76.6 76.6 76.6 76.6
38%48%48%48%48%
Projected Supply by Year Type
Agency
2050 Proj.
RWS
1st/Single
Dry Year
2nd Dry
Year
3rd Dry
Year
4th Dry
Year
5th Dry
Year
Alameda CWD 13.76 8.48 7.11 7.11 7.11 7.11
Brisbane / GVMID 0.97 0.60 0.50 0.50 0.50 0.50
Burlingame 4.44 2.74 2.29 2.29 2.29 2.29
Coastside CWD 1.16 0.71 0.60 0.60 0.60 0.60
CWS Total 26.89 16.57 13.89 13.89 13.89 13.89
Daly City 4.29 2.64 2.22 2.22 2.22 2.22
East Palo Alto 1.19 0.73 0.61 0.61 0.61 0.61
Estero MID 3.90 2.40 2.01 2.01 2.01 2.01
Hayward 19.71 12.14 10.17 10.17 10.17 10.17
Hillsborough 2.12 1.31 1.09 1.09 1.09 1.09
Menlo Park 2.83 1.75 1.46 1.46 1.46 1.46
Mid-Peninsula WD 3.43 2.11 1.77 1.77 1.77 1.77
Millbrae 2.29 1.41 1.18 1.18 1.18 1.18
Milpitas 5.52 3.40 2.85 2.85 2.85 2.85
Mountain View 9.55 5.88 4.93 4.93 4.93 4.93
North Coast CWD 2.36 1.46 1.22 1.22 1.22 1.22
Palo Alto 8.18 5.04 4.22 4.22 4.22 4.22
Purissima Hills WD 1.37 0.84 0.71 0.71 0.71 0.71
Redwood City 7.09 4.37 3.66 3.66 3.66 3.66
San Bruno 2.68 1.65 1.38 1.38 1.38 1.38
San Jose 4.50 2.77 2.32 2.32 2.32 2.32
Santa Clara 4.50 2.77 2.32 2.32 2.32 2.32
Stanford 2.13 1.31 1.10 1.10 1.10 1.10
Sunnyvale 12.58 7.75 6.50 6.50 6.50 6.50
Westborough WD 0.91 0.56 0.47 0.47 0.47 0.47
Total 148.35 91.4 76.6 76.6 76.6 76.6
Percent Cutback
Base Year
Scenario
Consecutive Dry Year
Wholesale RWS Demand
Wholesale RWS Supply
Attachment B: 2025 UWMP Wholesale Customer Dry Year Allocations
For UWMP Tables 7-1 through Table 7-4
2026
Without BDP
Basis of Water Supply Data
2026 2027 2028 2029 2030
130.1 130.9 131.6 132.4 133.2
130.1 130.9 131.6 132.4 133.2
0%0%0%0%0%
Projected Supply by Year Type Projected Supply by Year Type
Agency
2025 RWS
Purchases 2026 2027 2028 2029 2030
Alameda CWD 10.08 10.08 11.25 11.56 12.00 12.45
Brisbane / GVMID 0.68 0.68 0.68 0.68 0.68 0.68
Burlingame 3.23 3.23 3.23 3.23 3.23 3.23
Coastside CWD 1.01 1.01 1.01 1.01 1.01 1.01
CWS Total 29.50 29.50 29.50 29.50 29.50 29.50
Daly City 3.55 3.55 3.55 3.55 3.55 3.55
East Palo Alto 1.72 1.72 1.72 1.72 1.72 1.72
Estero MID 3.78 3.78 3.78 3.78 3.78 3.78
Hayward 13.66 13.66 13.66 13.66 13.66 13.66
Hillsborough 2.32 2.32 2.32 2.32 2.32 2.32
Menlo Park 2.72 2.72 2.72 2.72 2.72 2.72
Mid-Peninsula WD 2.34 2.34 2.34 2.34 2.34 2.34
Millbrae 1.81 1.81 1.81 1.81 1.81 1.81
Milpitas 4.68 4.68 4.68 4.68 4.68 4.68
Mountain View 7.69 7.69 7.69 7.69 7.69 7.69
North Coast CWD 2.58 2.58 2.58 2.58 2.58 2.58
Palo Alto 9.31 9.31 9.31 9.31 9.31 9.31
Purissima Hills WD 1.51 1.51 1.51 1.51 1.51 1.51
Redwood City 7.43 7.43 7.43 7.43 7.43 7.43
San Bruno 1.03 1.03 1.03 1.03 1.03 1.03
San Jose 3.99 3.99 3.99 3.99 3.99 3.99
Santa Clara 2.91 2.91 2.91 2.91 2.91 2.91
Stanford 1.59 1.59 1.59 1.59 1.59 1.59
Sunnyvale 10.28 10.28 10.28 10.28 10.28 10.28
Westborough WD 0.70 0.70 0.70 0.70 0.70 0.70
Total 130.12 130.12 131.28 131.59 132.03 132.48
Wholesale RWS Supply
Percent Cutback
Consecutive Dry Year
Wholesale RWS Demand
Base Year
Scenario
Attachment B: 2025 UWMP Wholesale Customer Dry Year Allocations
For UWMP Tables 7-1 through Table 7-4
2030
Without BDP
Basis of Water Supply Data
1st/Single 2nd 3rd 4th 5th
133.9 133.9 133.9 133.9 133.9
133.9 133.9 133.9 133.9 133.9
0%0%0%0%0%
Projected Supply by Year Type Projected Supply by Year Type
Agency
2030 Proj.
RWS
1st/Single
Dry Year
2nd Dry
Year
3rd Dry
Year
4th Dry
Year
5th Dry
Year
Alameda CWD 11.25 11.25 11.25 11.25 11.25 11.25
Brisbane / GVMID 0.94 0.94 0.94 0.94 0.94 0.94
Burlingame 3.92 3.92 3.92 3.92 3.92 3.92
Coastside CWD 1.17 1.17 1.17 1.17 1.17 1.17
CWS Total 27.04 27.04 27.04 27.04 27.04 27.04
Daly City 4.29 4.29 4.29 4.29 4.29 4.29
East Palo Alto 1.19 1.19 1.19 1.19 1.19 1.19
Estero MID 3.90 3.90 3.90 3.90 3.90 3.90
Hayward 14.74 14.74 14.74 14.74 14.74 14.74
Hillsborough 2.09 2.09 2.09 2.09 2.09 2.09
Menlo Park 2.58 2.58 2.58 2.58 2.58 2.58
Mid-Peninsula WD 2.82 2.82 2.82 2.82 2.82 2.82
Millbrae 1.91 1.91 1.91 1.91 1.91 1.91
Milpitas 5.30 5.30 5.30 5.30 5.30 5.30
Mountain View 7.87 7.87 7.87 7.87 7.87 7.87
North Coast CWD 2.23 2.23 2.23 2.23 2.23 2.23
Palo Alto 8.30 8.30 8.30 8.30 8.30 8.30
Purissima Hills WD 1.36 1.36 1.36 1.36 1.36 1.36
Redwood City 6.84 6.84 6.84 6.84 6.84 6.84
San Bruno 1.85 1.85 1.85 1.85 1.85 1.85
San Jose 4.50 4.50 4.50 4.50 4.50 4.50
Santa Clara 4.50 4.50 4.50 4.50 4.50 4.50
Stanford 1.77 1.77 1.77 1.77 1.77 1.77
Sunnyvale 10.72 10.72 10.72 10.72 10.72 10.72
Westborough WD 0.82 0.82 0.82 0.82 0.82 0.82
Total 133.92 133.92 133.92 133.92 133.92 133.92
Wholesale RWS Supply
Percent Cutback
Consecutive Dry Year
Wholesale RWS Demand
Base Year
Scenario
Attachment B: 2025 UWMP Wholesale Customer Dry Year Allocations
For UWMP Tables 7-1 through Table 7-4
2035
Without BDP
Basis of Water Supply Data
1st/Single 2nd 3rd 4th 5th
136.3 136.3 136.3 136.3 136.3
136.3 136.3 136.3 136.3 136.3
0%0%0%0%0%
Projected Supply by Year Type Projected Supply by Year Type
Agency
2035 Proj.
RWS
1st/Single
Dry Year
2nd Dry
Year
3rd Dry
Year
4th Dry
Year
5th Dry
Year
Alameda CWD 11.56 11.56 11.56 11.56 11.56 11.56
Brisbane / GVMID 0.95 0.95 0.95 0.95 0.95 0.95
Burlingame 3.99 3.99 3.99 3.99 3.99 3.99
Coastside CWD 1.16 1.16 1.16 1.16 1.16 1.16
CWS Total 26.89 26.89 26.89 26.89 26.89 26.89
Daly City 4.29 4.29 4.29 4.29 4.29 4.29
East Palo Alto 1.19 1.19 1.19 1.19 1.19 1.19
Estero MID 3.92 3.92 3.92 3.92 3.92 3.92
Hayward 15.66 15.66 15.66 15.66 15.66 15.66
Hillsborough 2.08 2.08 2.08 2.08 2.08 2.08
Menlo Park 2.64 2.64 2.64 2.64 2.64 2.64
Mid-Peninsula WD 2.97 2.97 2.97 2.97 2.97 2.97
Millbrae 1.99 1.99 1.99 1.99 1.99 1.99
Milpitas 5.35 5.35 5.35 5.35 5.35 5.35
Mountain View 8.12 8.12 8.12 8.12 8.12 8.12
North Coast CWD 2.29 2.29 2.29 2.29 2.29 2.29
Palo Alto 8.20 8.20 8.20 8.20 8.20 8.20
Purissima Hills WD 1.35 1.35 1.35 1.35 1.35 1.35
Redwood City 6.54 6.54 6.54 6.54 6.54 6.54
San Bruno 2.27 2.27 2.27 2.27 2.27 2.27
San Jose 4.50 4.50 4.50 4.50 4.50 4.50
Santa Clara 4.50 4.50 4.50 4.50 4.50 4.50
Stanford 1.96 1.96 1.96 1.96 1.96 1.96
Sunnyvale 11.15 11.15 11.15 11.15 11.15 11.15
Westborough WD 0.80 0.80 0.80 0.80 0.80 0.80
Total 136.32 136.32 136.32 136.32 136.32 136.32
Wholesale RWS Supply
Percent Cutback
Consecutive Dry Year
Wholesale RWS Demand
Base Year
Scenario
Attachment B: 2025 UWMP Wholesale Customer Dry Year Allocations
For UWMP Tables 7-1 through Table 7-4
2040
Without BDP
Basis of Water Supply Data
1st/Single 2nd 3rd 4th 5th
140.6 140.6 140.6 140.6 140.6
140.6 140.6 140.6 140.6 140.6
0%0%0%0%0%
Projected Supply by Year Type Projected Supply by Year Type
Agency
2040 Proj.
RWS
1st/Single
Dry Year
2nd Dry
Year
3rd Dry
Year
4th Dry
Year
5th Dry
Year
Alameda CWD 12.00 12.00 12.00 12.00 12.00 12.00
Brisbane / GVMID 0.97 0.97 0.97 0.97 0.97 0.97
Burlingame 4.15 4.15 4.15 4.15 4.15 4.15
Coastside CWD 1.16 1.16 1.16 1.16 1.16 1.16
CWS Total 26.93 26.93 26.93 26.93 26.93 26.93
Daly City 4.29 4.29 4.29 4.29 4.29 4.29
East Palo Alto 1.19 1.19 1.19 1.19 1.19 1.19
Estero MID 3.93 3.93 3.93 3.93 3.93 3.93
Hayward 16.82 16.82 16.82 16.82 16.82 16.82
Hillsborough 2.09 2.09 2.09 2.09 2.09 2.09
Menlo Park 2.71 2.71 2.71 2.71 2.71 2.71
Mid-Peninsula WD 3.18 3.18 3.18 3.18 3.18 3.18
Millbrae 2.09 2.09 2.09 2.09 2.09 2.09
Milpitas 5.41 5.41 5.41 5.41 5.41 5.41
Mountain View 8.59 8.59 8.59 8.59 8.59 8.59
North Coast CWD 2.37 2.37 2.37 2.37 2.37 2.37
Palo Alto 8.15 8.15 8.15 8.15 8.15 8.15
Purissima Hills WD 1.36 1.36 1.36 1.36 1.36 1.36
Redwood City 6.73 6.73 6.73 6.73 6.73 6.73
San Bruno 2.68 2.68 2.68 2.68 2.68 2.68
San Jose 4.50 4.50 4.50 4.50 4.50 4.50
Santa Clara 4.50 4.50 4.50 4.50 4.50 4.50
Stanford 2.02 2.02 2.02 2.02 2.02 2.02
Sunnyvale 11.92 11.92 11.92 11.92 11.92 11.92
Westborough WD 0.84 0.84 0.84 0.84 0.84 0.84
Total 140.57 140.57 140.57 140.57 140.57 140.57
Wholesale RWS Supply
Percent Cutback
Consecutive Dry Year
Wholesale RWS Demand
Base Year
Scenario
Attachment B: 2025 UWMP Wholesale Customer Dry Year Allocations
For UWMP Tables 7-1 through Table 7-4
2045
Without BDP
Basis of Water Supply Data
1st/Single 2nd 3rd 4th 5th
144.1 144.1 144.1 144.1 144.1
144.1 144.1 144.1 144.1 144.1
0%0%0%0%0%
Projected Supply by Year Type Projected Supply by Year Type
Agency
2045 Proj.
RWS
1st/Single
Dry Year
2nd Dry
Year
3rd Dry
Year
4th Dry
Year
5th Dry
Year
Alameda CWD 12.45 12.45 12.45 12.45 12.45 12.45
Brisbane / GVMID 0.97 0.97 0.97 0.97 0.97 0.97
Burlingame 4.30 4.30 4.30 4.30 4.30 4.30
Coastside CWD 1.16 1.16 1.16 1.16 1.16 1.16
CWS Total 26.80 26.80 26.80 26.80 26.80 26.80
Daly City 4.29 4.29 4.29 4.29 4.29 4.29
East Palo Alto 1.18 1.18 1.18 1.18 1.18 1.18
Estero MID 3.91 3.91 3.91 3.91 3.91 3.91
Hayward 18.14 18.14 18.14 18.14 18.14 18.14
Hillsborough 2.11 2.11 2.11 2.11 2.11 2.11
Menlo Park 2.76 2.76 2.76 2.76 2.76 2.76
Mid-Peninsula WD 3.39 3.39 3.39 3.39 3.39 3.39
Millbrae 2.18 2.18 2.18 2.18 2.18 2.18
Milpitas 5.46 5.46 5.46 5.46 5.46 5.46
Mountain View 9.04 9.04 9.04 9.04 9.04 9.04
North Coast CWD 2.36 2.36 2.36 2.36 2.36 2.36
Palo Alto 8.15 8.15 8.15 8.15 8.15 8.15
Purissima Hills WD 1.36 1.36 1.36 1.36 1.36 1.36
Redwood City 6.91 6.91 6.91 6.91 6.91 6.91
San Bruno 2.68 2.68 2.68 2.68 2.68 2.68
San Jose 4.50 4.50 4.50 4.50 4.50 4.50
Santa Clara 4.50 4.50 4.50 4.50 4.50 4.50
Stanford 2.07 2.07 2.07 2.07 2.07 2.07
Sunnyvale 12.58 12.58 12.58 12.58 12.58 12.58
Westborough WD 0.88 0.88 0.88 0.88 0.88 0.88
Total 144.11 144.11 144.11 144.11 144.11 144.11
Wholesale RWS Supply
Percent Cutback
Consecutive Dry Year
Wholesale RWS Demand
Base Year
Scenario
Attachment B: 2025 UWMP Wholesale Customer Dry Year Allocations
For UWMP Tables 7-2 through Table 7-4
2050
Without BDP
Basis of Water Supply Data
1st/Single 2nd 3rd 4th 5th
148.3 148.3 148.3 148.3 148.3
148.3 148.3 148.3 148.3 148.3
0%0%0%0%0%
Projected Supply by Year Type
Agency
2050 Proj.
RWS
1st/Single
Dry Year
2nd Dry
Year
3rd Dry
Year
4th Dry
Year
5th Dry
Year
Alameda CWD 13.76 13.76 13.76 13.76 13.76 13.76
Brisbane / GVMID 0.97 0.97 0.97 0.97 0.97 0.97
Burlingame 4.44 4.44 4.44 4.44 4.44 4.44
Coastside CWD 1.16 1.16 1.16 1.16 1.16 1.16
CWS Total 26.89 26.89 26.89 26.89 26.89 26.89
Daly City 4.29 4.29 4.29 4.29 4.29 4.29
East Palo Alto 1.19 1.19 1.19 1.19 1.19 1.19
Estero MID 3.90 3.90 3.90 3.90 3.90 3.90
Hayward 19.71 19.71 19.71 19.71 19.71 19.71
Hillsborough 2.12 2.12 2.12 2.12 2.12 2.12
Menlo Park 2.83 2.83 2.83 2.83 2.83 2.83
Mid-Peninsula WD 3.43 3.43 3.43 3.43 3.43 3.43
Millbrae 2.29 2.29 2.29 2.29 2.29 2.29
Milpitas 5.52 5.52 5.52 5.52 5.52 5.52
Mountain View 9.55 9.55 9.55 9.55 9.55 9.55
North Coast CWD 2.36 2.36 2.36 2.36 2.36 2.36
Palo Alto 8.18 8.18 8.18 8.18 8.18 8.18
Purissima Hills WD 1.37 1.37 1.37 1.37 1.37 1.37
Redwood City 7.09 7.09 7.09 7.09 7.09 7.09
San Bruno 2.68 2.68 2.68 2.68 2.68 2.68
San Jose 4.50 4.50 4.50 4.50 4.50 4.50
Santa Clara 4.50 4.50 4.50 4.50 4.50 4.50
Stanford 2.13 2.13 2.13 2.13 2.13 2.13
Sunnyvale 12.58 12.58 12.58 12.58 12.58 12.58
Westborough WD 0.91 0.91 0.91 0.91 0.91 0.91
Total 148.35 148.35 148.35 148.35 148.35 148.35
Percent Cutback
Wholesale RWS Supply
Wholesale RWS Demand
Consecutive Dry Year
Scenario
Base Year
March 31, 2026 www.paloalto.gov
Upcoming Draft 2025 Urban Water Management Plan Preliminary Update
Utilities Advisory Commission
2
PURPOSE
•Background
•Key Updates
•Long-term water demand projections
•Water reliability assessment
•Water use restrictions
•Use and planned use of recycled water
•Next Steps
AGENDA
•This item is for discussion, and no action is requested.
•Key updates to the City’s upcoming draft 2025 Urban Water Management Plan (UWMP) are being
presented to the Utilities Advisory Commission (UAC) for discussion. Staff will return to the UAC in
May 2026 for a recommendation to Council to adopt the 2025 UWMP.
3
BACKGROUND
•State requires urban water suppliers to adopt an UWMP every five years demonstrating
water supply reliability over a 20-year planning timeframe based on development plans
in normal, dry and multiple dry years.
•Suppliers must have a current UWMP on file to be eligible for any water grant or loan
administered by the California Department of Water Resources (DWR) and the State
Water Resources Control Board.
•City is drawing up to $192 million on a reimbursement basis from a State Revolving
Fund loan to finance the Secondary Treatment Upgrades project at the Regional
Water Quality Control Plant.
•2025 UWMP must be adopted by City Council and submitted to the DWR by July 1, 2026.
•Regional and local demand forecasts can be updated as needed for supply planning
purposes, including San Francisco Public Utilities Commission (SFPUC)'s alternative water
supply planning.
4
REQUIRED INPUTS
•Inputs from City
•City planning documents (i.e., Housing Element, Regional
Housing Needs Allocation [RHNA]).
•Population projections from state, regional, or local
agencies for the service area (i.e., ABAG 2040).
•Adopted codes, standards, ordinances that drive water
savings assumptions.
•Inputs from Supplier – SFPUC
•Supply availability for normal, single dry, and multiple dry
years.
•Based on wholesale agencies’ purchase projections.
•Constraints/assumptions that affect supply availability.
5
LONG-TERM WATER DEMAND PROJECTIONS
2025 Demand Study
•Prepared for the City in coordination with Bay Area Water
Supply & Conservation Agency (BAWSCA) to support regional
planning efforts and to facilitate preparation of the 2025
UWMP.
•Direct input for the water demand, supply, and reliability
projections for the City’s 2025 UWMP.
•Model developed by BAWSCA’s technical consultant, Hazen
and Sawyer, utilizing information provided by staff to project
water demand through 2050.
•Intended as a planning tool. Designed to be “scenario-ready”
so that core assumptions can be varied as planning needs and
conditions evolve. Not intended to predict the future.
6
•2025 Demand Forecast
(orange line)
•Reflects a 5% decrease
in demand over the
forecast period.
•Ranges from 9% to
19% below the 2020
Demand Study
forecast (purple line)
HISTORICAL AND PROJECTED DEMAND COMPARISONS
7
WATER RELIABILITY ASSESSMENT
Projected Regional Water System (RWS) Wholesale Multiple Dry-Year Cutbacks,
With Bay-Delta Plan - 2025 UWMP vs 2020 UWMP
2030 2035 2040 2045 2050
31.1%31.1%42.2%42.2%42.2%
33.0%33.0%42.9%42.9%42.9%
35.2%35.2%45.1%45.1%45.1%
36.8%36.8%46.8%46.8%46.8%
38.4%38.4%48.4%48.4%48.4%
36.3%36.5%36.5%45.5%
45.4%45.6%45.6%45.5%
45.4%45.6%45.6%45.5%
45.4%45.6%52.0%53.7%
45.4%50.1%52.0%53.7%
2025 Urban Water Management Plan
2020 Urban Water Management Plan
Fifth Year
Fourth Year
Third Year
Second Year
First Year
First Year
Second Year
Third Year
Fourth Year
Fifth Year
Factors:
•2025 RWS demand
assumptions are
about 11% lower
than in 2020.
•Changes to Water
System Improvement
Project (WSIP)
project assumptions.
8
WATER USE RESTRICTIONS
City of Palo Alto Existing Permanent Water Use Restrictions:
•No flooding, runoff, use automatic shut-off valves.
•Repair leaks, broken irrigation systems.
•Use non-potable water when available for non-potable purposes
(decorative fountains, car washes, etc.).
•No potable irrigation between 10 a.m. - 6 p.m.
New Requirements:
•Compliance with California Assembly Bill 1572 - prohibiting the
use of (potable) drinking water on non-functional turf (decorative
grass). State legislation goes into effect on January 1:
•2027: Government properties;
•2028: All Commercial, Industrial and Institutional properties;
•2029: Homeowners' Association common areas.