Loading...
HomeMy WebLinkAboutStaff Report 11246 City of Palo Alto (ID # 11246) City Council Staff Report Report Type: Consent Calendar Meeting Date: 5/18/2020 City of Palo Alto Page 1 Summary Title: 2353 Webster Street: Appeal of Director's Decision on Individual Review Application Title: QUASI-JUDICIAL. 2353 Webster Street [18PLN-00339]: Appeal of Director’s Approval of an Individual Review Application to Demolish an Existing One-Story 1,593 Sq Ft Home and Construct a Two-Story Home ( Approx. 3,133 Sq Ft) with a Basement and an Attached Garage; Approved by the Director of Planning & Development Services on March 17, 2020. Zoning District: Single-Family Residential (R-1) From: City Manager Lead Department: Planning and Development Services Recommendation Staff recommends City Council decline to hear the appeal and uphold the Planning and Development Services Director’s approval of the Individual Review (IR) application (file 18PLN- 00339). The project is a new two-story home at 2353 Webster Street. Executive Summary This request is an appeal of the Director’s approval of a Single-Family Individual Review (IR) application for a new two-story home. Three or more Council Members’ votes would be needed to remove this item off the consent calendar and to set the matter for a future hearing. Appellants Jack Morton and Mary Ellen White are the owners of 2343 Webster Street, a single- story home abutting the subject property. As required by the Palo Alto Municipal Code, staff mailed all decision and hearing notices regarding the project to the immediate neighbors, including the appellant. Following the Director’s Hearing on February 27, 2020, the Director upheld the tentative approval. The appellant is concerned about the 300-year-old oak tree in the proposed home’s rear yard, dewatering to construct the basement, and the size of the proposed house. City of Palo Alto Page 2 Background Individual Review applications are reviewed and approved through the Low-Density Residential Review Process set forth in Palo Alto Municipal Code (PAMC) 18.77.075. First, a project receives a staff-level ‘proposed Director’s decision’; a tentative staff decision subject to a hearing request process. Any adjacent property owner or occupant may request a Director’s Hearing within 14 days of the decision. If requested, the Director then sets and conducts a noticed public hearing on the project, receives testimony, and makes a decision that becomes final 14 days thereafter. Following this approval, and within the 14-day appeal period, owners or occupants of abutting properties may appeal the decision to Council. Appeals are placed on the Council consent calendar for final action. The Council has two options. The first option is for Council to approve the item on consent, adopting the findings and affirming the Director’s decision. The second option, if three or more Council members vote to remove the project from the consent, is for Council to set an appeal hearing. This appeal hearing would be scheduled as soon as practical, and neighbors would be notified in accordance with Palo Alto Municipal Code (PAMC) Section 18.77.075. Project Review and Director’s Approval The Individual Review program applies to the construction of new two-story homes and second story additions. The program is intended to mitigate the effects of the additions on neighboring single-family homes (per PAMC Section 18.12.110(a)). Development applications subject to the IR regulations must be consistent with the IR guidelines (per PAMC Section 18.12.110(d)). The IR guidelines include criteria related to (1) basic site planning, (2) neighborhood compatibility for height, mass and scale, (3) resolution of architectural form, massing and roof lines, (4) visual character of street facing facades and entries, and (5) placement of second-story windows and decks for privacy. The subject IR application was originally submitted on October 4, 2018 and received comments from the Planning, Public Works Engineering, and Urban Forestry departments, in addition to IR Guideline Review by the City’s consulting architect. The appellant and other neighbors initially provided comments on October 21, 2018 and these comments were incorporated into the review. Initial Revisions The applicant submitted revised plans on June 6, 2019 to address comments prepared by staff on November 1, 2018. The following are comments related to neighbor concerns and how they were addressed in the resubmitted plans, which staff then tentatively approved: City of Palo Alto Page 3 Concern Response Side facing windows and wrap-around balcony would create a privacy issue for side neighbors Initial plans did not meet IR Guideline #5. Approved design has only one second floor side-facing window, located in the stairway 6’8” above the landing. Balcony is limited to the rear only, with a 5’8” privacy wall to prevent views to near side, over 50 feet away from the opposite site (acceptable to neighbors). Basement construction could harm 300-year old Oak tree on the subject property Urban Forestry staff requested an Arborist Report. The owner hired Davey Tree Expert Company to prepare the report and act as project Arborist. Urban Forestry staff reviewed the report and requested edits as necessary to ensure appropriate tree protection. Additional Revisions: The applicant further refined the design and arborist report for additional reviews. These revisions, submitted on August 26, 2019 and November 20, 2019, were tentatively approved on December 5, 2019. On December 19, 2019, the appellant made a timely request for a Director’s Hearing. Staff held an additional meeting with the appellant and other interested neighbors on January 14, 2020 to better understand the neighbor’s concerns, which were not fully presented in the request letter. Director’s Hearing February 27, 2020 During the hearing, the appellants reiterated the concerns they previously expressed to staff. They stated that (1) they believed the house was too large for typical single-family use, (2) the 300-year-old Oak tree was not appropriately protected, and (3) dewatering for the basement could damage the tree and/or neighboring properties. The project complies or has been conditioned to comply with applicable dewatering regulations. These regulations were updated in 2017 and 2018 in response to residents’ concerns. The concerns were that temporary construction-related groundwater dewatering wasted water, damaged structures, trees and vegetation, and depleted or altered the flow of groundwater. The current dewatering regulations are included as Attachment E. It was also determined during the hearing that additional research was needed to understand if the tentative conditions incorporated all possible measures to protect the tree. Between the hearing and the Director’s decision, Urban Forestry staff corresponded with the project arborist, and made additional recommendations that were incorporated as conditions in the Director’s Decision. City of Palo Alto Page 4 Director’s Approval and Appeal On March 16, 2020, following the Director’s Hearing, the Director approved the application, imposing additional conditions requiring that: • Plans include additional tree protection measures (Conditions #1 a-g, #23-32), including requiring: o 14 feet of the existing foundation nearest the tree to remain – abandoned, not removed; o Demolition of the remaining existing foundation by air spade and/or hand tools only and be performed under the supervision of a Certified Arborist; o Recommendations from the final Arborist Report be included as conditions of approval; o Tree protection fencing installed prior to demolition, where feasible, and no closer than 40 feet from the specimen Valley Oak. o the applicant’s consulting arborist to make daily visits during demolition to the site and prepare a daily memo attesting to the contractor’s compliance with the arborists report and related Urban Forestry conditions of approval (Condition Numbers 27-40) o During demolition and construction, all pervious area within the TPZ shall be covered with 12 inches of woodchips and a layer of plywood, to the satisfaction of Urban Forestry (Condition Numbers 28b and 28c) o The location for the dewatering monitoring well required in Condition Number 43 shall be determined by the Director of Public Works prior to building permit approval to ensure the goals of the monitoring well are balanced with the need to protect the specimen Valley Oak. • Staff will also hold a preconstruction meeting to discuss the construction phase conditions with those who will be onsite during construction (Condition #2). On March 31, 2020, the appellant appealed the Director’s approval of the IR application (Attachment B), based on concerns for the health of the oak tree, even with the additional review by Urban Forestry and new conditions added. Discussion The project meets all five of the guidelines for Individual Review. The project complies with the Public Works regulations for dewatering, and Urban Forestry regulations for protecting the 300- year-old Oak tree. Findings for the project’s compliance with IR guidelines are provided in Attachment F, with analysis provided by the City’s consulting architect and dated October 3, 2019. The letter also includes recommended conditions of approval, which were incorporated as Condition #5e and #13a. The project is expected to meet all requirements for dewatering, in accordance with the standard conditions of approval. City of Palo Alto Page 5 The Director added the conditions to further clarify how to protect the 300-year-old Oak tree. They are provided in Attachment A as Condition of Approval #1, Special Conditions. In total, the project has met the findings for approval, and the project approval is enhanced with the special Director’s conditions to ensure protection of the 300-year-old Oak tree. Therefore, staff recommends upholding the Director’s decision to approve the project. Alternative to Staff Recommendation The Council’s alternative to the staff recommendation, as outlined in PAMC Section 18.77.075(g)(2), is to remove the recommendation from the consent calendar with three votes. The Council could set the application for a public hearing before the City Council, to enable the City Council to hear the item, adopt findings, and take action on the application. If the Council so directs, staff will identify a date for the hearing and will provide appropriate public notice in advance of the hearing. Stakeholder Engagement Notices of the pending application and tentative decision were provided in accordance with the municipal code. Staff has been in regular communication with applicant and appellant. A director’s hearing was held that resulted in additional conditions being imposed on the project. The applicant and appellant have been advised of this item being scheduled on the agenda and opportunities to provide public input. Policy Implications The Director’s decision to approve the application is consistent with staff’s implementation of the Individual Review Guidelines, and with the policies and intent of the Individual Review Process. This is the third appeal of an Individual Review project since 2015. It is, however, the first appeal during the five year time period of a home that is not within an Eichler neighborhood. Also notably absent from the appeal are privacy concerns, which are typically an appeal topic associated with IR applications. Environmental Review This project is exempt from the provision of the California Environmental Quality Act (CEQA) per Section 15303(a) of the CEQA Guidelines. Attachments: Attachment A: Director's Approval Letter (PDF) Attachment B: Appeal Letter (PDF) Attachment C: Tentative Approval Letter (PDF) City of Palo Alto Page 6 Attachment D: Location Map (PDF) Attachment E: 2020 Regulations for Dewatering during Construction of Below Ground Structures (PDF) Attachment F: Consulting Architect's Review Letter (PDF) Attachment G: September 2019 Arborist Report (PDF) Attachment H: Project Plans (DOCX) March 16, 2020 Yali Zhou 2353 Webster St. Palo Alto, CA 94301 Gordana Pavlović 602 Hawthorne Avenue Palo Alto, CA 94301 Email: design@gordana.net SUBJECT: 2353 Webster Street - Individual Review Application 18PLN-00339 On December 5, 2019, the Director of Planning and Community Environment conditionally approved Single Family Individual Review application 18PLN-00339 for a new two-story residence with a basement at 2353 Webster St. This approval was granted pursuant to the Palo Alto Municipal Code (PAMC) Sections 18.12.110 and 18.77.075. The conditionally approved project plan set received November 20, 2019, meets the Palo Alto Single Family Individual Review Guidelines, and complies with the R-1 zone district regulations and other applicable City regulations for development as conditioned. Prior to the approval becoming effective, a timely request for Director’s Hearing was received and a Director’s Hearing was held on February 27, 2020. On March 16, 2020, the Director of Planning and Community Environment upheld the conditionally approved project. PROJECT DESCRIPTION The proposal is a request by Gordana Pavlović for Single Family Individual Review to allow demolition of an existing single story residence and construction of a new two-story single-family residence with a basement and an attached one-car garage in the R-1 zoning district, as shown on the plans received on November 20, 2019. DIRECTOR’S HEARING The hearing was requested by Jack Morton and Mary Ellen White. Their concerns included the size of the home, protection for the 300-year old Oak tree, and dewatering during basement construction. DECISION AND FINDINGS The Director of Planning and Community Environment finds that the project (as submitted on November 20, 2019 and as conditioned here) is in compliance with both the Municipal Code and the Individual Review Design Guidelines. The Director finds: DocuSign Envelope ID: 5F69F71E-F7A2-4BBE-A368-09596D6D50FD 2353 Webster Street 18PLN-00339 March 16, 2020 2  The project has been reviewed and found to be in compliance with the Palo Alto Municipal Code and IR Guidelines 1-5.  This property contains a 300-year-old specimen valley oak that requires specific and carefully prescribed tree protection measures during construction.  Potential impacts of dewatering are sufficiently reduced and monitored through Public Works standard conditions of approval and policies for dewatering. This approval will become effective 14 calendar days from the postmark date of this letter, unless an appeal is filed, as provided by Chapter 18.77.075 of the PAMC. An appeal may be filed by written request with the City Clerk before the date the Director’s decision becomes final. The written request shall be accompanied by a fee, as set forth in the municipal fee schedule. Only an applicant, or the owner or tenant of an adjacent property may appeal. If you need assistance reviewing the plans, you may visit the City’s Development Center at 285 Hamilton Avenue. A copy of this letter shall accompany all future requests for City permits relating to this approval. This approval expires in 24 months from the effective date. Should you have any questions regarding this approval, please feel free to contact Emily Foley, AICP at emily.foley@cityofpaloalto.org. Sincerely, Jonathan Lait, AICP Director of Planning and Development Services Attachment A – Findings for Approval cc: Jack Morton, 2343 Webster St, Palo Alto, CA 94301, jack@mortoncpa.com Mary Ellen 2343 Webster St, Palo Alto, CA 94301, mycek@earthlink.net Sandra Browman, 2397 Webster St, Palo Alto, CA 94301 sandra.browman@yahoo.com Keith Bennett, kbennett@luxsci.net Neighbor notification list DocuSign Envelope ID: 5F69F71E-F7A2-4BBE-A368-09596D6D50FD 2353 Webster Street 18PLN-00339 March 16, 2020 3 Attachment A INDIVIDUAL REVIEW CONDITIONS OF APPROVAL 2353 Webster Street 18PLN-00339 March 16, 2020 The approval is subject to compliance with the following conditions. The property owner is solely responsible for the conditions of approval being met. Planning staff recommends the property owner discuss the conditions of approval with the contractor, designer, etc. and contact Planning staff with any questions. PLANNING DIVISION 1. SPECIAL CONDITIONS. Based on the significance of the 300 year old specimen Valley Oak tree (Quercus lobata), the following special conditions apply: a. The 14 feet of the existing foundation nearest the tree shall be abandoned (left in place - remain as existing). b. Demolition of the remaining existing foundation shall use air spade and/or hand tools only and be performed under the supervision of a Certified Arborist. c. The final Arborist Report shall be reviewed and approved by the City’s Urban Forester and printed on the building permit plans; all recommendations from the Arborist Report shall be followed. d. The tree protection fencing shall be installed prior to demolition, where feasible. Following demolition, the remainder of the tree protection fencing shall be installed per approved plans and no closer than 40 feet from the specimen Valley Oak. e. During demolition, the applicant’s consulting arborist shall make daily visits to the site and prepare a daily memo attesting to the contractor’s compliance with the arborists report and related Urban Forestry conditions of approval (Condition Numbers 27-40) f. During demolition and construction, all pervious area within the TPZ shall be covered with 12 inches of woodchips and a layer of plywood, to the satisfaction of Urban Forestry (Condition Numbers 28b and 28c) g. The location for the dewatering monitoring well required in Condition Number 43 shall be determined by the Director of Public Works prior to building permit approval to ensure the goals of the monitoring well are balanced with the need to protect the specimen Valley Oak. 2. PRECONSTRUCTION MEETING. A preconstruction meeting shall occur at the time of building permit issuance. The contractor, homeowner, contracted project arborist, as well as the project planner, urban forester, building official and supervising building inspector shall be present at this meeting to discuss construction-phase conditions of approval, particularly arborist supervision of demolition of the existing structure. DocuSign Envelope ID: 5F69F71E-F7A2-4BBE-A368-09596D6D50FD 2353 Webster Street 18PLN-00339 March 16, 2020 4 3. CONFORMANCE WITH PLANS. Construction and development shall conform to the approved plans entitled, “Yali Residence, 2353 Webster Street, Palo Alto, California,” stamped as received by the City on November 20, 2019 on file with the Planning Department, 250 Hamilton Avenue, Palo Alto, California except as modified by these conditions of approval. 4. BUILDING PERMIT. Apply for a building permit and meet any and all conditions of the Planning, Fire, Public Works, and Building Departments. 5. BUILDING PERMIT PLAN SET. A copy of this cover letter and conditions of approval shall be printed on the second page of the plans submitted for building permit. Project plans submitted for Building permits shall incorporate the following changes: a. Gravel is not allowed within the first 10 feet of the property. b. The roof overhang at the front entry counts towards the Lot Coverage. Please show this on the FAR diagram and cover sheet data table. c. The T sheets shall be updated with the arborist report dated September 2019 which was submitted separately from the Plan Set and received November 20, 2019 d. Tree protection fencing shall be shown on Site Plan, matching the Arborist Report e. A row of tall shrubs and/or at least two trees along the left side lot line starting from near the rear corner of the house and extending to the rear lot setback line. The trees and/or tall shrubs should be evergreen and form a relatively continuous screen with plants that can grow to at 20 feet tall under normal conditions. This shall be shown on the Site Plan. f. Provide the correct GB-1 sheet, signed by the applicant or owner 6. PROJECT MODIFICATIONS: All modifications to the approved project shall be submitted for review and approval prior to construction. If during the Building Permit review and construction phase, the project is modified by the applicant, it is the responsibility of the applicant to contact the Planning Division/project planner directly to obtain approval of the project modification. It is the applicant’s responsibility to highlight any proposed changes to the project and to bring it to the project planner’s attention. 7. OBSCURED/TRANSLUCENT GLAZING. All obscure glazing, as shown on the plan set, shall be permanent in nature and shall remain for the life of the structure. Obscure glazing is either decorative glazing that does not allow views through placed into the window frame or acid etched or similar permanent alteration of the glass. Films or like additions to clear glass are not permitted where obscure glazing is shown. Obscure glazing shall not be altered in the future and shall be replaced with like materials if damaged. If operable, these windows shall open towards the public right-of-way. 8. REQUIRED PARKING: All single family homes shall be provided with a minimum of one covered parking space (10 foot by 20 foot interior dimensions) and one uncovered parking space (8.5 feet by 17.5 feet). DocuSign Envelope ID: 5F69F71E-F7A2-4BBE-A368-09596D6D50FD 2353 Webster Street 18PLN-00339 March 16, 2020 5 9. UTILITY LOCATIONS: In no case shall utilities be placed in a location that requires equipment and/or bollards to encroach into a required parking space. In no case shall a pipeline be placed within 10 feet of a proposed tree and/or tree designated to remain. 10. NOISE PRODUCING EQUIPMENT: All noise producing equipment shall be located outside of required setbacks, except they may project 6 feet into the required street side setbacks. In accordance with Section 9.10.030, No person shall produce, suffer or allow to be produced by any machine, animal or device, or any combination of same, on residential property, a noise level more than six dB above the local ambient at any point outside of the property plane. 11. DAYLIGHT PLANE: The daylight plane must clear the point where the wall plane intersects the top of the roof material. 12. IMPERVIOUS SURFACE: A minimum of 60 % of the required front yard shall have a permeable surface that permits water absorption directly into the soil (Section 18.12.040 (h)). The building permit plan set shall include a diagram demonstrating compliance. 13. REQUIRED IR LANDSCAPING/TREES. The following landscaping is required to ensure the project’s conformance with the City’s IR Guidelines and therefore must remain for the life of the structure. Required new screening trees and shrubs shall be a minimum size of 24 inch box and measure at least eight (8) feet tall. a. A row of shrubs or a minimum of two large trees as described in Condition #3e. b. Existing oak tree in rear yard 14. PROJECT ARBORIST. The property owner shall hire a certified arborist to ensure the project conforms to all Planning and Urban Forestry conditions related to landscaping/trees. 15. TREE PROTECTION FENCING. Tree protection fencing shall be required for the front street tree and the rear yard oak tree. 16. FENCES. Fences and walls shall comply with the applicable provisions of Chapter 16.24, Fences, of the Palo Alto Municipal Code (PAMC). Heights of all new and existing fencing must be shown on the Building Permit plans. a. Where the existing fence is located off the subject property and/or where the existing fence is failing, a new Code compliant fence shall be constructed. 17. LIGHT WELLS. Railings around light wells shall be screened from street view. Screening may consist of plant material or fencing. DocuSign Envelope ID: 5F69F71E-F7A2-4BBE-A368-09596D6D50FD 2353 Webster Street 18PLN-00339 March 16, 2020 6 18. BASEMENT WALLS: Basement retaining walls shall not extend beyond the exterior wall plane of the first floor of the house, excluding lightwells, below grade patios and approved extensions, to the satisfaction of the Director of Planning. 19. BASEMENT CONSTRUCTION WALLS: Any walls, temporary or otherwise, installed to facilitate construction of a basement shall be removed or constructed in such a way as to not significantly restrict the growth of required landscaping, to the satisfaction of the Director of Planning. 20. DECONSTRUCTION SURVEY: A Deconstruction Survey is required for demolition permit applications submitted on or after January 1, 2017. This survey submittal shall include a list of materials that are salvageable from the project as well as the values of such materials. At this time, the City’s only approved vendor for this service is The ReUse People. Contact them to schedule this FREE service by phone (888)588-9490 or e-mail info@thereusepeople.org. More information can be found at www.TheReusePeople.org. If you have further questions, please contact Scott McKay at scott.mckay@cityofpaloalto.org. 21. PLANNING FINAL INSPECTION. A Planning Division Final inspection will be required to determine substantial compliance with the approved plans prior to the scheduling of a Building Division final. Any revisions during the building process must be approved by Planning, including but not limited to; materials, fenestration and hard surface locations. Contact your Project Planner at the number below to schedule this inspection. 22. PERMIT EXPIRATION. The project approval shall be valid for a period of two years from the original date of approval. Application for a one year extension of this entitlement may be made prior to expiration, by emailing the Current Planning Support Staff (Alicia Spotwood - Alicia.Spotwood@CityofPaloAlto.org). If a timely extension is not received, or the project has already received an extension and the applicant still wishes to pursue this project, they must first file for a new Planning application and pay the associated fees. This new application will be reviewed for conformance with the regulations in place at that time. 23. INDEMNITY: To the extent permitted by law, the Applicant shall indemnify and hold harmless the City, its City Council, its officers, employees and agents (the “indemnified parties”) from and against any claim, action, or proceeding brought by a third party against the indemnified parties and the applicant to attack, set aside or void, any permit or approval authorized hereby for the Project, including (without limitation) reimbursing the City for its actual attorneys’ fees and costs incurred in defense of the litigation. The City may, in its sole discretion, elect to defend any such action with attorneys of its own choice. GREEN BUILDING & ENERGY REACH CODE REQUIREMENTS: NOTICE FOR PERMIT APPLICATIONS SUBMITTED ON OR AFTER 1/1/20: Please be advised that the Palo Alto City Council has approved Energy Ordinance 5485 and Green Building Ordinance 5481 for all new permit applications. The Green Building Ordinance has an effective date of January 1st, 2020 and the Energy Reach Code Ordinance has an effective date DocuSign Envelope ID: 5F69F71E-F7A2-4BBE-A368-09596D6D50FD 2353 Webster Street 18PLN-00339 March 16, 2020 7 of April 1, 2020. To review the upcoming changes, visit the Development Services webpage .On the left-hand side under “EXPLORE”, hover over “Green Building” and select “Compliance.” You may also email Green Building at GreenBuilding@cityofpaloalto.org for specific questions about your project. 24. GREEN BUILDING CONDITIONS OF APPROVAL a) The project is a new construction residential building of any size** and therefore must meet the California Green Building Code mandatory requirements outlined in Chapter 4, (with local amendments) plus Tier 2 minimum pre-requisites and electives outlined in Appendix A4* (with local amendments). The project must hire a Green Building Special Inspector for a pre-permit third-party design review and a third-party green building inspection process. The project must select a Green Building Special Inspector from the City’s list of approved inspectors. PAMC 16.14.080 (Ord. 5481 § 1, 2019) (1) *Note: Projects subject to Tier 1 or Tier 2 shall not be required to fulfill any requirements outlined in Appendix A4.2 Energy Efficiency. All energy efficiency measures are found in the 2019 California Energy Code and the Palo Alto Energy Reach Code PAMC 16.17 & 16.18 as described in the Energy Reach Code section of this letter. (2) **Accessory Dwelling Unit (Detached) Exception: (a) Free standing detached Accessory Dwelling Units of new construction shall meet the following: (i) California Green Building Standards Code Mandatory plus Tier 2 prerequisite requirements. (ii) No Planning and Design electives. (iii) Two (2) Water Efficiency and Conservation electives. (iv) Two (2) Material Conservation and Resource Efficiency electives. (v) One (1) Environmental Quality elective. b) The project is a residential construction project of any size with a given valuation of $25,000 or more and therefore must meet the enhanced construction waste reduction at Tier 2 (80% construction waste reduction). PAMC 16.14.260 (Ord. 5481 § 1 (part), 2019) c) The project is a new detached single-family, dwelling and therefore shall comply with the following requirements for electric vehicle supply equipment (EVSE): (a) In general. The property owner shall provide Conduit Only, EVSE-Ready Outlet, or EVSE Installed for each residence. The property owner shall provide as minimum a panel capable to accommodate a dedicated branch circuit and service capacity to install at least a 208/240V, 50 amperes grounded AC outlet (Level 2 EVSE). The raceway shall terminate in close proximity to the proposed location of the charging system into a listed cabinet, box, enclosure, or receptacle. The raceway shall be installed so that minimal removal of materials is necessary to complete the final installation. The raceway shall have capacity to accommodate a 100-ampere circuit. (b) Design. The proposed location of a charging station may be internal or external to the dwelling, and shall be in close proximity to an on-site parking space. The DocuSign Envelope ID: 5F69F71E-F7A2-4BBE-A368-09596D6D50FD 2353 Webster Street 18PLN-00339 March 16, 2020 8 proposed design must comply with all applicable design guidelines, setbacks and other code requirements. PAMC 16.14.420 (Ord. 5481 §1, 2019) 25. LOCAL ENERGY REACH CODE CONDITIONS OF APPROVAL – Effective 4/1/20 a) The project includes new residential construction of any size and is submitted for building permit on or after April 1, 2020 and therefore triggers the Local Energy Efficiency Reach Code. All new residential construction projects of any size submitted after January 1, 2020 until March 31, 2020 shall comply with statewide mandatory energy standards as outlined in the 2019 California Energy Code, Title 24, Part 6. i) Single-Family Residential Options: (1) New single-family residential construction projects shall be designed to be all-electric. (2) The installation of fireplaces, space-conditioning equipment, water heating system, clothes drying and cooking appliances shall be electric and not fueled by natural gas. (a) An All-Electric Building complies with the performance standard if both the Total Energy Design Rating and the Energy Efficiency Design Rating for the Proposed Building are no greater than the corresponding Energy Design Ratings for the Standard Design Building. (b) The Energy Budget for newly constructed buildings is expressed in terms of the Energy Design Rating, which is based on TDV energy. The Energy Design Rating (EDR) has two components, the Energy Efficiency Design Rating, and the Solar Electric Generation and Demand Flexibility Design Rating. The Solar Electric Generation and Demand Flexibility Design Rating shall be subtracted from the Energy Efficiency Design Rating to determine the Total Energy Design Rating. The Proposed Building shall separately comply with the Energy Efficiency Design Rating and the Total Energy Design Rating. (i) Compliance demonstration requirements for performance standards: Certificate of Compliance. The Certificate of Compliance is prepared and signed by a Certified Energy Analyst and the Total Energy Design Rating of the Proposed Design shall be no greater than the Standard Design Building. (Ord. 5485 §1, 2019) b) Mandatory Photovoltaic (PV) Requirements: i) All new low-rise residential buildings shall have a photovoltaic (PV) system meeting the minimum qualification requirements as specified in Joint Appendix JA11, with annual electrical output equal to or greater than the dwelling’s annual electrical usage. (CEC §150.1, 2019) 26. Additional Green Building and Energy Reach Code information, ordinances and applications can be found at http://www.cityofpaloalto.org/gov/depts/ds/green_building/default.asp. If you have any questions DocuSign Envelope ID: 5F69F71E-F7A2-4BBE-A368-09596D6D50FD 2353 Webster Street 18PLN-00339 March 16, 2020 9 regarding Green Building requirements please call the Green Building Consultant at (650) 329-2179 or send an email to GreenBuilding@CityofPaloAlto.org. PUBLIC WORKS URBAN FORESTRY CONDITIONS – Catherine Mondkar catherine.mondkar@cityofpaloalto.org 27. SPECIAL CONDITIONS. The Applicant shall strictly adhere to the recommendations for tree preservation, pneumatic/hand evacuation, and to all tree protection measures as outlined in the 9/22/19 Davey Resources Group arborist report, or as updated thereafter. Additional tree protection protocol shall be followed as specified by Palo Alto Urban Forestry in the following items below. a) The first fourteen feet (14’) of the existing concrete slab closest to tree #5 (72” DBH Valley Oak, Quercus lobata) shall be left in place, abandoned, and therefore shall not demolished. Regarding the remaining portion of the concrete slab to be demolished within the TPZ, the construction procedures as described in Condition 27 below are to be employed for the demolition of the remaining twenty-six feet (26’) of existing concrete slab within the TPZ. 28. SPECIAL TREE PROTECTION MEASURES. The Contractor shall under the supervision of an ISA certified Arborist furnish the following tree protection materials on site prior to commencing demolition of the specified portion of the existing home foundation. a) No heavy equipment or vehicles of any sort are to be used within the tree protection zone (TPZ= DBHx10/12= 60’ TPZ). Hand tools and pneumatic air spades only are to be used within the TPZ for the purpose of demolition. No loading of equipment, materials or objects of any sort may be stored within the TPZ. b) 12” inches of wood chips topped with sheets of plywood shall be furnished within all pervious areas of the tree protection zone within the scope of work prior to beginning demolition. c) As pervious areas within the TPZ are gradually exposed, 12” inches of wood chips topped with sheets of plywood shall be furnished within the remaining areas of the TPZ . d) Only hand and pneumatic excavation are to be used during deconstruction of the existing foundation. e) As demolition progresses and pervious areas are surfaced, any roots exposed to the air for greater than one (1) hour are to be wrapped in burlap to maintain moisture and covered in original soil where possible. f) Following hand and pneumatic demolition of the specified portion on the existing foundation, type I tree protection fencing (as specified on the T-1 sheet) shall be installed to the extent of the TPZ as per plan drawings and maintained for the duration of the project. 29. TREE PROTECTION INSPECTIONS. In addition to standard tree protection fencing inspections, at the time of pneumatic demolition around tree #5, City Staff will perform a tree protection inspection to ensure that hand excavation and tree protection measures are being met as outlined in the above- mentioned conditions of approval. Following demolition of the specified portion of the foundation, another tree protection inspection by City staff will take place to ensure that the required fencing is in place. DocuSign Envelope ID: 5F69F71E-F7A2-4BBE-A368-09596D6D50FD 2353 Webster Street 18PLN-00339 March 16, 2020 10 30. ARBORIST CONSTRUCTION SUPERVISION. For the duration of hand demolition within the TPZ, the project Arborist shall make a daily visit on site to ensure that tree protection measures, materials and best practices are being employed by the contractor and on-site foreman overseeing the work. 31. TREE APPRAISAL. Prior to the issuance of a grading or building permit, the applicant shall prepare and secure a tree appraisal for tree #5 (72” DBH Valley Oak, Quercus lobata). The appraisal of the condition and replacement value of tree #5 shall recognize the location of the tree in the proposed development. The appraisal may be part of the Tree Survey Report or listed separately. For the purposes of tree appraisal, the monetary market or replacement value shall be determined using the most recent version of the “Guide for Plant Appraisal”, in conjunction with the Species and Classification Guide for Northern California. The appraisal shall be performed at the applicant’s expense, and the appraiser shall be subject to the Director’s approval. See PAMC 8.10.020(k)(2), 8.10.110 (b)(2), and sections 6.25 and 6.40 of the Palo Alto Tree Technical Manual. 32. TREE APPRAISAL DURATION. The tree appraisal duration period shall be five years from the date of final occupancy. A tree shall be considered dead when the main leader has died back, 25% of the crown is dead or if major trunk or root damage is evident. A new tree or trees of equal or greater appraised value shall be planted in the same area by the property owner. Landscape area and irrigation shall be readapted to provide optimum growing conditions for the replacement tree(s). The replacement tree(s) that are planted shall be subject to a new two-year establishment and monitoring program. The project sponsor shall provide an annual tree evaluation report as originally required. 33. TREE PROTECTION COMPLIANCE. The owner and contractor shall implement all protection and inspection schedule measures, design recommendations and construction scheduling as stated in the TPR & Sheet T-1, and is subject to code compliance action pursuant to PAMC 8.10.080. The required protective fencing shall remain in place until final landscaping and inspection of the project. Project arborist approval must be obtained and documented in the monthly activity report sent to the City. The mandatory Contractor and Arborist Monthly Tree Activity Report shall be sent monthly to the City (pwps@cityofpaloalto.org) beginning with the initial verification approval, using the template in the Tree Technical Manual, Addendum 11. 34. PLAN CHANGES. Revisions and/or changes to plans before or during construction shall be reviewed and responded to by the (a) project site arborist, or (b) landscape architect with written letter of acceptance before submitting the revision to the Building Department for review by Planning, PW or Urban Forestry. 35. TREE DAMAGE. Tree Damage, Injury Mitigation and Inspections apply to Contractor. Reporting, injury mitigation measures and arborist inspection schedule (1-5) apply pursuant to TTM, Section 2.20- 2.30. Contractor shall be responsible for the repair or replacement of any publicly owned or protected trees that are damaged during the course of construction, pursuant to Title 8 of the Palo Alto Municipal Code, and city Tree Technical Manual, Section 2.25. DocuSign Envelope ID: 5F69F71E-F7A2-4BBE-A368-09596D6D50FD 2353 Webster Street 18PLN-00339 March 16, 2020 11 36. GENERAL. The following general tree preservation measures apply to all trees to be retained: No storage of material, topsoil, vehicles or equipment shall be permitted within the tree enclosure area. The ground under and around the tree canopy area shall not be altered. Trees to be retained shall be irrigated, aerated and maintained as necessary to ensure survival. 37. BUILDING PERMIT SUBMITTAL- PROJECT ARBORIST CERTIFICATION LETTER. Prior to submittal for staff review, attach a Project Arborist Certification Letter that he/she has; (a) reviewed the entire building permit plan set submittal and, (b) affirm that ongoing Contractor/Project Arborist site monitoring inspections and reporting have been arranged with the contractor or owner (see Sheet T-1) and, (c) understands that design revisions (site or plan changes) within a TPZ will be routed to Project Arborist/Contractor for review prior to approval from City. 38. TREE PROTECTION VERIFICATION. Prior to any site work verification from the contractor that the required protective fencing is in place shall be submitted to the Urban Forestry Section. The fencing shall contain required warning sign and remain in place until final inspection of the project. 39. EXCAVATION RESTRICTIONS APPLY (TTM, Sec. 2.20 C & D). Any approved grading, digging or trenching beneath a tree canopy shall be performed using ‘air-spade’ method as a preference, with manual hand shovel as a backup. For utility trenching, including sewer line, roots exposed with diameter of 1.5 inches and greater shall remain intact and not be damaged. If directional boring method is used to tunnel beneath roots, then Table 2-1, Trenching and Tunneling Distance, shall be printed on the final plans to be implemented by Contractor. 40. PLAN SET REQUIREMENTS. The final Plans submitted for building permit shall include the following information and notes on relevant plan sheets: a) SHEET T-1, BUILDING PERMIT. The building permit plan set will include the City’s full-sized, Sheet T-1 (Tree Protection-it's Part of the Plan!), available on the Development Center website at http://www.cityofpaloalto.org/civicax/filebank/documents/31783. The Applicant shall complete and sign the Tree Disclosure Statement and recognize the Project Arborist Tree Activity Inspection Schedule. Monthly reporting to Urban Forestry/Contractor is mandatory. (Insp. #1: applies to all projects; with tree preservation report: Insp. #1-7 applies) b) The Tree Preservation Report (TPR). All sheets of the Applicant’s TPR approved by the City for full implementation by Contractor, shall be printed on numbered Sheet T-1 (T-2, T-3, etc) and added to the sheet index. c) Plans to show protective tree fencing. The Plan Set (esp. site, demolition, grading & drainage, foundation, irrigation, tree disposition, utility sheets, etc.) must delineate/show the correct configuration of Type I, Type II or Type III fencing around each Regulated Tree, using a bold dashed line enclosing the Tree Protection Zone (Standard Dwg. #605, Sheet T-1; City Tree Technical Manual, Section 6.35-Site Plans); or by using the Project Arborist’s unique diagram for each Tree Protection Zone enclosure. DocuSign Envelope ID: 5F69F71E-F7A2-4BBE-A368-09596D6D50FD 2353 Webster Street 18PLN-00339 March 16, 2020 12 PUBLIC WORKS ENGINEERING CONDITIONS – Ajay Kumar ajay.kumar@cityofpaloalto.org The following shall be addressed prior to issuance of a Building Permit, Excavation and Grading Permit, Certificate of Compliance, Street Work Permit and/or Encroachment Permit. 41. DEMOLITION PLAN: Place the following note adjacent to an affected tree on the Site Plan and Demolition Plan: “Excavation activities associated with the proposed scope of work shall occur no closer than 10-feet from the existing street tree, or as approved by the Urban Forestry Division contact 650-496-5953. Any changes shall be approved by the same”. 42. GRADING PERMIT: Separate Excavation and Grading Permit will be required for grading activities on private property that fill, excavate, store or dispose of 100 cubic yards or more based on PAMC Section 16.28.060. Applicant shall prepare and submit an excavation and grading permit to Public Works separately from the building permit set. The permit application and instructions are available at the Development Center and on our website. http://www.cityofpaloalto.org/gov/depts/pwd/forms_and_permits.asp 43. GRADING & DRAINAGE PLAN: The plan set must include a grading & drainage plan prepared by a licensed professional that includes existing and proposed spot elevations, earthwork volumes, finished floor elevations, area drain and bubbler locations, drainage flow arrows to demonstrate proper drainage of the site. Adjacent grades must slope away from the house a minimum of 2% or 5% for 10-feet per 2013 CBC section 1804.3. Downspouts and splashblocks should be shown on this plan, as well as any site drainage features such as swales, area drains, bubblers, etc. Grading that increases drainage onto, or blocks existing drainage from neighboring properties, will not be allowed. Public Works generally does not allow rainwater to be collected and discharged into the street gutter, but encourages the developer to keep rainwater onsite as much as feasible by directing runoff to landscaped and other pervious areas of the site. See the Grading & Drainage Plan Guidelines for New Single Family Residences on the City’s website. http://www.cityofpaloalto.org/civicax/filebank/documents/2717 44. BASEMENT DRAINAGE: Due to high groundwater throughout much of the City and Public Works prohibiting the pumping and discharging of groundwater, perforated pipe drainage systems at the exterior of the basement walls or under the slab are not allowed for this site. A drainage system is, however, required for all exterior basement-level spaces, such as lightwells, patios or stairwells. This system consists of a sump, a sump pump, a backflow preventer, and a closed pipe from the pump to a dissipation device onsite at least 10-feet from the property line and 3-feet from side an rear property lines, such as a bubbler box in a landscaped area, so that water can percolate into the soil and/or sheet flow across the site. Include these dimensions on the plan. The device must not allow stagnant water that could become mosquito habitat. Additionally, the plans must show that exterior basement-level spaces are at least 7-3/4” below any adjacent windowsills or doorsills to minimize the potential for flooding the basement. Public Works recommends a waterproofing consultant be retained to design and inspect the vapor barrier and waterproofing systems for the basement. DocuSign Envelope ID: 5F69F71E-F7A2-4BBE-A368-09596D6D50FD 2353 Webster Street 18PLN-00339 March 16, 2020 13 45. BASEMENT SHORING: Shoring Plans prepared by a licensed professional are required for the Basement Excavation and shall be submitted with the Grading and Excavation Permit. Shoring for the basement excavation, including tiebacks, must not extend onto adjacent private property or into the City right-of-way without having first obtained written permission from the private property owners and/or an encroachment permit from Public Works. 46. The site drainage system that collects runoff from downspouts and landscape area shall be a separated from the pump system that discharges runoff from light wells. Plot and clearly label the two separate systems and including the separate outfalls for each system. 47. UTILITIES: Note that all above ground utilities, such as transformer, backflow preventer, gas meters, etc., shall be located within project site but accessible from the street. Any new or relocated utilities will correspond with approved locations from City Utilities Department. 48. GEOTECHNICAL REPORT: Shall clearly identify the highest projected groundwater level to be encountered in the area of the proposed basement in the future will be ______ feet below existing grade. Provide the following note on the Final Grading Plans. “In my professional judgement, the highest projected groundwater level to be encountered in the area of the proposed basement in the future will be ______ feet below existing grade. As a result, the proposed drainage system for the basement retaining wall will not encounter and pump groundwater during the life of this wall.” 49. DEWATERING: Excavation may require dewatering during construction. Public Works only allows groundwater drawdown well dewatering. Open pit groundwater dewatering is not allowed. Dewatering is only allowed from April through October due to inadequate capacity in our storm drain system. The geotechnical report for this site must list the highest anticipated groundwater level. We recommend that a piezometer be installed in the soil boring. The contractor shall determine the depth to groundwater immediately prior to excavation by using a piezometer or by drilling and exploratory hole. Based on the determined groundwater depth and season the contractor may be required to dewater the site or stop all grading and excavation work. In addition Public Works may require that all groundwater be tested for contaminants prior to initial discharge and at intervals during dewatering. If testing is required, the contractor must retain an independent testing firm to test the discharge water for contaminants Public Works specifies and submit the results to Public Works. Public Works reviews and approves dewatering plans as part of a Grading Permit and Dewatering Permit. The applicant can include a dewatering plan in the building permit plan set in order to obtain approval of the plan during the building permit review, but the contractor will still be required to obtain a Grading Permit prior to dewatering. Alternatively, the applicant must include the above dewatering requirements in a note on the site plan. Public Works has dewatering guidelines available at the Development Center and on our website. https://www.cityofpaloalto.org/gov/depts/pwd/forms_and_permits/default.asp DocuSign Envelope ID: 5F69F71E-F7A2-4BBE-A368-09596D6D50FD 2353 Webster Street 18PLN-00339 March 16, 2020 14 50. WATER FILLING STATION: applicant shall install a water station for the non-potable reuse of the dewatering water. This water station shall be constructed within private property, next to the right- of-way, (typically, behind the sidewalk). The station shall be accessible 24 hours a day for the filling of water carrying vehicles (i.e. street sweepers, etc.). The water station may also be used for onsite dust control. Before a discharge permit can be issued, the water supply station shall be installed, ready for operational and inspected by Public Works. The groundwater will also need to be tested for contaminants and chemical properties for the non-potable use. The discharge permit cannot be issued until the test results are received. Additional information regarding the station will be made available on the City’s website under Public Works. 51. WORK IN THE RIGHT-OF-WAY: The plans must clearly indicate any work that is proposed in the public right-of-way, such as sidewalk replacement, driveway approach, or utility laterals. The plans must include notes that the work must be done per City standards and that the contractor performing this work must first obtain a Street Work Permit from Public Works at the Development Center. If a new driveway is in a different location than the existing driveway, then the sidewalk associated with the new driveway must be replaced with a thickened (6” thick instead of the standard 4” thick) section. Additionally, curb cuts and driveway approaches for abandoned driveways must be replaced with new curb, gutter and planter strip. 52. Provide the following note on the Site Plan and adjacent to the work within the Public road right- of-way. “Any construction within the city’s public road right-of-way shall have an approved Permit for Construction in the Public Street prior to commencement of this work. THE PERFORMANCE OF THIS WORK IS NOT AUTHORIZED BY THE BUILDING PERMIT ISSUANCE BUT SHOWN ON THE BUILDING PERMIT FOR INFORMATION ONLY.” 53. Provide the following note on the Site Plan and Grading and Drainage Plan: “Contractor shall not stage, store, or stockpile any material or equipment within the public road right-of-way.” Construction phasing shall be coordinate to keep materials and equipment onsite. 54. SIDEWALK, CURB & GUTTER: As part of this project, the applicant shall replace those portions of the existing sidewalks, curbs, gutters or driveway approaches in the public right-of-way along the frontage(s) of the property. Contact Public Works’ inspector at 650-496-6929 to arrange a site visit so that the inspector can discuss the extent of replacement work along the public road. The site plan submitted with the building permit plan set must show the extent of the replacement work. The plan must note that any work in the right-of-way must be done per Public Works’ standards by a licensed contractor who must first obtain a Street Work Permit from Public Works at the Development Center. Provide site direction sheet obtained from PW inspector in plan set. 55. Any existing driveway to be abandoned shall be replaced with standard curb & gutter. This work must be included within a Permit for Construction in the Public Street from the Public Works DocuSign Envelope ID: 5F69F71E-F7A2-4BBE-A368-09596D6D50FD 2353 Webster Street 18PLN-00339 March 16, 2020 15 Department. A note of this requirement shall be placed on the plans adjacent to the area on the Site Plan. 56. IMPERVIOUS SURFACE AREA: The project will be creating or replacing 500 square feet or more of impervious surface. Accordingly, the applicant shall provide calculations of the existing and proposed impervious surface areas with the building permit application. The Impervious Area Worksheet for Land Developments form and instructions are available at the Development Center or on our website. 57. PUBLIC WORKS STANDARDS CONDITIONS: The City's full-sized "Standard Conditions" sheet must be included in the plan set. Copies are available from Public Works on our website: http://www.cityofpaloalto.org/civicax/filebank/blobdload.aspx?t=67175.06&BlobID=66261 58. STORM WATER POLLUTION PREVENTION: The City's full-sized "Pollution Prevention - It's Part of the Plan" sheet must be included in the plan set. Copies are available from Public Works on our website http://www.cityofpaloalto.org/civicax/filebank/documents/2732 59. This project triggers the California Regional Water Quality Control Board’s revised provision C.3 for storm water regulations (incorporated into the Palo Alto Municipal Code, Section 16.11) that apply to residential land development projects that create or replace between 2,500 and 10,000 square feet of impervious surface area. The applicant must implement one or more of the following site design measures on the grading and drainage plan:  Direct roof runoff into cisterns or rain barrels for reuse.  Direct roof runoff onto vegetated areas.  Direct runoff from sidewalks, walkways, and/or patios onto vegetated areas.  Direct runoff from driveways and/or uncovered parking lots onto vegetated areas.  Construct sidewalks, walkways, and/or patios with permeable surfaces.  Construct driveways, and/or uncovered parking lots with permeable surfaces 60. Provide the following as a note on the Site Plan: “The contractor may be required to submit a logistics plan to the Public Works Department prior to commencing work that addresses all impacts to the City’s right-of-way, including, but not limited to: pedestrian control, traffic control, truck routes, material deliveries, contractor’s parking, concrete pours, crane lifts, work hours, noise control, dust control, storm water pollution prevention, contractor’s contact, noticing of affected surrounding properties , and schedule of work. The requirement to submit a logistics plan will be dependent on the number of applications Public Works Engineering receives within close proximity to help mitigate and control the impact to the public-right-of-way. If necessary, Public Works may require a Logistics Plan during construction.” End Project Conditions DocuSign Envelope ID: 5F69F71E-F7A2-4BBE-A368-09596D6D50FD 0 PLANNING &DEVELOPMENT SERVICES CITY OF 250 Hami ton Avenue,5th FloorPALOPaloAlto,CA 91a301 ALTO (650)329-2441 December 5,2019 Gordana PavIovh 602 Hawthorne Avenue Palo Alto,CA 94301 Email:design@gordana.net SUBJECT:2353 Webster Street (18PLN-00339)Individual Review The Director of Planning and Community Environment has conditionally approved your Single Family Individual Review application to allow demolition of an exi5ting single story residence and construction of a new two-story single-family residence with an attached one-cat garage in the R-1 zoning district. This approval was granted pursuant to the Palo Alto Municipal Code Sections 18.12.110 and 18.77.075. The proposed project is exempt from the provisions of the California Environmental Quality Act (CEQA) in accordance with Guideline Section 15303 (New Construction).As conditioned,the project meets all five of the Palo Alto Single Family Individual Review Guidelines and complies with the R-1 Zone District development regulations. This approval will become effective 14 days from the postmark date of this letter,unless the Planning Department receives a written request for a Directors Heating prior to the end of the business day 14 calendar-days after the postmark date.Only an applicant,or the owner or tenant of an adjacent property may request a hearing.As the plans may have been revised since the original submittal, interested parties may wish to review the tentatively approved plans online at the City’s Planning webpage bit.ly/PABuildingEye.If you need assistance reviewing the plans,you may visit the City’s Development Center at 285 Hamilton Avenue. This letter and attached conditions and findings shall be printed onto building permit plans relating to this approval.if the building permit has not been issued and construction commenced within two years from the effective approval date,this approval will expire.Awritten request for an extension may be submitted prior to the expiration date.The Director may grant a one-year extension of this approval.Should you have any questions regarding this approval,please do not hesitate to call Emily Foley,Project Planner,at (650)617-3125 or e-mail at Emily.foley@cityofpaloalto.org. Sincerely, Emily Foley,AICP Associate Planner cc:Neighbor notification list (adjacent neighbors)Attachment:Conditions of Approval Property Owner 0 0 2353 Webster St.approval ndividual Review 18PLN-00339 Page 2 of 12 INDIVIDUAL REVIEW CONDITIONS OF APPROVAL 2353 Webster Street,18PLN-00339 The approval is subject to compliance with the following conditions.The property owner is solely responsible for the conditions of approval being met.Planning staff recommends the property owner discuss the conditions of approval with the contractor,designer,etc.and contact Planning staff with any questions. The approval is subject to the following conditions; PLANNING DIVISION CONDITIONS: 1.CONFORMANCE WITH PLANS.Construction and development shall conform to the approved plans entitled,“Vail Residence,2353 Webster Street,Palo Alto,California,”stamped as received by the City on November 20,2019 on file with the Planning Department,250 Hamilton Avenue,Palo Alto, California except as modified by these conditions of approval. 2.BUILDING PERMIT.Apply for a building permit and meet any and all conditions of the Planning, Fire,Public Works,and Building Departments. 3.BUILDING PERMIT PLAN SET.A copy of this cover letter and conditions of approval shall be printed on the second page of the plans submitted for building permit.Project plans submitted for Building permits shall incorporate the following changes: a.Gravel is not allowed within the first 10 feet of the property. b.The roof overhang at the front entry counts towards the Lot Coverage.Please show this on the FAR diagram and covet sheet data table. c.The Tsheets shall be updated with the arborist report dated September 2019 which was submitted separately from the Plan Set and received November 20,2019 U.Tree protection fencing shall be shown on Site Plan,matching the Arborist Report e.A row of tall shrubs and/or at least two trees along the left side lot line starting from near the tear corner of the house and extending to the rear lot setback line.The trees and/or tall shrubs should be evergreen and form a relatively continuous screen with plants that can grow to at 20 feet tall under normat conditions.This shall be shown on the Site Plan. f.Provide the correct GB-i sheet,signed by the applicant or owner 4.PROJECT MODIFICATIONS:All modifications to the approved project shall be submitted for review and approval prior to construction,If during the Building Permit review and construction phase,the project is modified by the applicant,it is the responsibility of the applicant to contact the Planning Division/project planner directly to obtain approval of the project modification.It is the applicant’s responsibility to highlight any proposed changes to the project and to bring it to the project planner’s attention. 2353 Webster St.approval Individual Review 18PLN-00339 Page 3 of 12 5.OBSCURED/TRANSLUCENT GLAZING.All obscure glazing,as shown on the plan set,shall be permanent in nature and shall remain for the life of the structure.Obscure glazing is either decorative glazing that does not allow views through placed into the window frame or acid etched or similar permanent alteration of the glass.Films or like additions to cleat glass are not permitted where obscure glazing is shown.Obscure glazing shall not be altered in the future and shall be replaced with like materials if damaged.If operable,these windows shall open towards the public right-of-way. 6.REQUIRED PARKING:All single family homes shall be provided with a minimum of one covered parking space (10 foot by 20 foot interior dimensions)and one uncovered parking space (8.5 feet by 17.5 feet). 7.UTILITY LOCATIONS:In no case shall utilities be placed in a location that requires equipment and/or bollards to encroach into a required parking space.In no case shall a pipeline be placed within 10 feet of a proposed tree and/or tree designated to remain. 8.NOISE PRODUCING EQUIPMENT:All noise producing equipment shall be located outside of required setbacks,except they may project 6 feet into the required street side setbacks.In accordance with Section 9.10.030,No person shall produce,suffer or allow to be produced by any machine,animal or device,or any combination of same,on residential property,a noise level more than six dB above the local ambient at any point outside of the property plane. 9.DAYLIGHT PLANE:The daylight plane must clear the point where the wall plane intersects the top of the roof material. 10.IMPERVIOUS SURFACE:A minimum of 60%of the required front yard shall have a permeable surface that permits water absorption directly into the soil (Section 18.12.040 fh)).The building permit plan set shall include a diagram demonstrating compliance. 11.REQUIRED IR LANDSCAPING/TREES.The following landscaping is required to ensure the project’s conformance with the City’s IR Guidelines and therefore must remain for the life of the structure. Required new screening trees and shrubs shall be a minimum size of 24 inch box and measure at least eight (8)feet tall. a.A row of shrubs or a minimum of two large trees as described in Condition 113e. b.Existing oak tree in rear yard 12.PROJECT ARBORIST.The property owner shall hire a certified arborist to ensure the project conforms to all Planning and Urban Forestry conditions related to landscaping/trees. 13.TREE PROTECTION FENCING.Tree protection fencing shall be required for the front street tree and the rear yard oak tree. 0 a 2353 Webster St.approval Individual Review 18PLNO0339 Page 4 of 12 14.FENCES.Fences and walls shall comply with the applicable provisions of Chapter 16.24,Fences,of the Palo Alto Municipal Code (PAMC).Heights of all new and existing fencing must be shown on the Building Permit plans. a.Where the existing fence is located off the subject property and/or where the existing fence is failing,a new Code compliant fence shall be constructed. 15.LIGHT WELLS.Railings around light wells shall be screened from Street view.Screening may consist of plant material or fencing. 16.BASEMENT WALLS:Basement retaining walls shall not extend beyond the exterior wall plane of the first floor of the house,excluding lightwells,below grade patios and approved extensions,to the satisfaction of the Director of Planning. 17.BASEMENT CONSTRUCTION WALLS:Any walls,temporary or otherwise,installed to facilitate construction of a basement shall be removed or constructed in such a way as to not significantly restrict the growth of required landscaping,to the satisfaction of the Director of Planning. 18.DECONSTRUCTION SURVEY:ADeconstruction Survey is required for demolition permit applications submitted on or after January 1,2017.This survey submittal shall include a list of materials that are salvageable from the project as well as the values of such materials.At this time,the City’s only approved vendor for this service is The ReUse People,Contact them to schedule this FREE service by phone (888)588-9490 or e-mail info@thereusepeople.org.More information can be found at www.TheReusePeople.org.If you have further questions,please contact Scott McKay at scott.mckay@cityofpaloalto.org. 19.PLANNING FINAL INSPECTION.A Planning Division Final inspection will be required to determine substantial compliance with the approved plans prior to the scheduling of a Building Division final. Any revisions during the building process must be approved by Planning,including but not limited to;materials,fenestration and hard surface locations.Contact your Project Planner at the number below to schedule this inspection. 20.PERMIT EXPIRATION.The project approval shall be valid for a period of two years from the original date of approval.Application for a one year extension of this entitlement may be made prior to expiration,by emailing the Current Planning Support Staff (Alicia Spotwood - Alicia.Spotwood(ECityofPaIoAlto.org).If a timely extension is not received,or the project ha5 already received an extension and the applicant still wishes to pursue this project,they must first file for a new Planning application and pay the associated fees.This new application will be reviewed for conformance with the regulations in place at that time. 21.INDEMNITY:To the extent permitted by law,the Applicant shall indemnify and hold harmless the City,its City Council,its officers,employees and agents (the “indemnified parties”)from and against any claim,action,or proceeding brought by a third party against the indemnified parties and the applicant to attack,set aside or void,any permit or approval authorized hereby for the Project, 0 2333 Webster St.approval Individual Review 8PLN-00339 Page 5 of 12 including (without limitation)reimbursing the City for its actual attorneys’fees and costs incurred in defense of the litigation.The City may,in its sole discretion,elect to defend any such action with attorneys of its own choice. GREEN BUILDING &ENERGY REACH CODE REQUIREMENTS: NOTICE FOR PERMITAPPLICATIONS SUBMI7TED ON ORAFTER 1/1/17:Please be advised that the Palo Alto City Council has approved Energy Ordinance 5383 and Green Building Ordinance 5393 far all new permit applications with on effective date for Januoty 1r,2017.To review the upcoming changes,visit the Development Services webpage .On the left-hand side under “EXPLORE”,hover over “Green Building”and select “Compliance.”For information regarding the Model Water Efficient Landscape Ordinance,please see the Outdoot Water Efficiency Webpoge for compliance documentation.You may also email Green Building at GreenBuildiaa@cityofpploaltp,orp Jot specfic questions about your project. 22.GREEN BUILDING CONDITIONS OF APPROVAL a)The proiect is a new construction residential building of any size and therefore must meet the California Green Building Code mandatory requirements outlined in Chapter 4,(with local amendments)plus Tier 2 minimum pre-requisites and electives outlined In Appendix A4*(with local amendments).The project must hire a Green Building Special Inspector for a pre-permit third-party design review and a third-party green building inspection process.The project must select a Green Building Special Inspector from the City’s list of approved inspectors.PAMC 16.14.080 (Ord.5393 5 1,2016) (1)*Note:Projects subject to Tier 1 or Tier 2 shall not be required to fulfill any requirements outlined in Appendix A4.2 Energy Efficiency.All energy efficiency measures are found in the 2016 California Energy Code and the Palo Alto Energy Reach Code PAMC 16.17 &16.18 as described in the Energy Reach Code section of this letter. b)Model Water Efficient Landscape Ordinance (MWELO):The project is a residential new construction project with an aggregate landscape area of 500 square feet or mote included in the project scope of work and therefore shall comply with the requirements of the Landscape Documentation Package (5492.3).Please see the Outdoor Water Efficiency Webpage for compliance documentation.(MWELO Title 23,Chapter 2.7) c)The prolect is a residential construction project of any size and therefore must meet the enhanced construction waste reduction at Tier 2 (80%construction waste reduction).PAMC 16.14.260 (Ord.5393 §1 (part),2016) U)The project is a new detached single-family dwelling and therefore shall comply with the following requirements for electric vehicle supply equipment fEVSE): (a)The property owner shall provide as minimum a panel capable to accommodate a dedicated branch circuit and service capacity to install at least a 208/240V,50 amperes grounded ACoutlet (Level 2 EVSE).The raceway shall terminate in close proximity to the proposed location of the charging system into a listed cabinet,box, enclosure,or receptacle.The raceway shall be installed so that minimal removal of 0 2353 Webster St.approval Individual Review 18PLN-00339 Page 6 of 12 materials is necessary to complete the final installation.The raceway shall have capacity to accommodate a 100-ampere circuit. (b)Design.The proposed location of a charging station may be internal or external to the dwelling,and shall be in close proximity to an on-site parking space.The proposed design must comply with all applicable design guidelines,setbacks and other code requirements.PAMC 16.14.420 (Ord.5393 §2,2016) 23.LOCAL ENERGY REACH CODE CONDITIONS OF APPROVAL a)The project includes new residential construction of any size and therefore triggers the Local Energy Efficiency Reach Code.For all new single-family residential there are two compliance options and one all-electric exception. i)Single-Family Residential Options: (1)OPTION 1:Performance:New single-family residential construction projects without a solar photovoltaic (PV)system,the performance approach specified within the 2016 California Energy Code shall be used to demonstrate that the TDV Energy of the proposed building is at least 10%less than the TDV Energy of the Standard Design,ifthe proposed building does not include a PV systems. (a)Solar Ready Infrastructure:A dedicated solar zone shall be located on the rood or overhang of the building and have a total area no less than 500 square feet.Install a conduit extending from the roofline and terminating at the electrical panel. (2)OPTION 2:Performance:New single-family residential construction projects JJi a solar photovoltaic (PV)system,the performance approach specified within the 2016 California Energy Code shall be used to demonstrate that the TDV Energy of proposed single-family residential construction is at least 20%less than the TDV Energy of the Standard Design,if the proposed building includes a photovoltaic system. (a)Solar Ready Infrastructure:A dedicated solar zone shall be located on the rood or overhang of the building and have a total area no less than 500 square feet.Install a conduit extending from the roofline and terminating at the electrical panel. b)All Electric Exemption: I)All-Electric Exception to the Local Energy Reach Code:New single-family residential construction that is designed and built to be all-electric shall be exempt from the requirements of Section 100.3.Local Energy Efficiency Reach Code. 24.Additional Green Building and Energy Reach Code information,ordinances and applications can be found at http://www.cityofpaloafto.org/gov/depts/ds/green_buildingJdefault.asp.If you have any question5 regarding Green Building requirements please call the Green Building Consultant at (650)329-2179. 2353 Webster St.approval Individual Review 18PCN-00339 Page7ofl2 PUBLIC WORKS URBAN FORESTRY CONDtTIONS —Catherine Mondkar catherine.mondkaricitypfoaloalto.org 25.The Applicant must strictly adhere to the recommendations for tree preservation and pneumatic/hand evacuation and to all tree protection measures as outlined in the 9/22/19 Davey Resources Group arborist report. In addition to standard tree protection fencing inspections,inspections at the time of demotion/excavation around tree #5 will take place by City Staff to ensure that hand excavation and tree protection measures are being met.Additional tree protection fencing inspections may applythroughout the course of construction.See general comments below: 26.TREE PROTECTION COMPLIANCE.The owner and contractor shall implement all protection and inspection schedule measures,design recommendations and construction scheduling as stated in the TPR &Sheet T-1,and is subject to code compliance action pursuant to PAMC 8.10.080.The required protective fencing shall remain in place until final landscaping and inspection of the project. Project arborist approval must be obtained and documented in the monthly activity report sent to the City.The mandatory Contractor and Arborist Monthly Tree Activity Report shall be sent monthly to the City (pwps@cityofpaloalto.org)beginning with the initial verification approval,using the template in the Tree Technical Manual,Addendum 11. 27.PLAN CHANGES.Revisions and/or changes to plans before or during construction shall be reviewed and responded to by the (a)project site arborist,or fb)landscape architect with written letter of acceptance before submitting the revision to the Building Department for review by Planning,PW or Urban Forestry. 2$.TREE DAMAGE.Tree Damage,Injury Mitigation and Inspections apply to Contractor,Reporting,injury mitigation measures and arborist inspection schedule (1-5)apply pursuant toUM,Section 2.20-2.30. Contractor shall be responsible for the repair or replacement of any publicly owned or protected trees that are damaged during the course of construction,pursuant to Title $of the Palo Alto Municipal Code,and city Tree Technical Manual,Section 2.25. 29.GENERAL.The following general tree preservation measures apply to all trees to be retained:No storage of material,topsoil,vehicles or equipment shall be permitted within the tree enclosure area. The ground under and around the tree canopy area shall not be altered.Trees to be retained shall be irrigated,aerated and maintained as necessary to ensure survival. 30.BUILDING PERMIT SUBMITTAL-PROJECT ARBORIST CERTIFICATION LETTER.Prior to submittal for staff review,attach a Project Arborist Certification Letter that he/she has;(a)reviewed the entice building permit plan set submittal and,(b)affirm that ongoing Contractor/Project Arborist site monitoring inspections and reporting have been arranged with the contractor or owner (see Sheet T-1)and,fc)understands that design revisions (site or plan changes)within a TPZ will be routed to Project Arborist/Contractor for review prior to approval from City. 0 0 2353 Webster St.approval Individual Review 18PLN-00339 Page 8 of 12 31.TREE PROTECTION VERIFICATION.Prior to any site work verification from the contractor that the required protective fencing is in place shall be submitted to the Urban Forestry Section.The fencing shall contain required warning sign and remain in place until final inspection of the project. 32.EXCAVATION RESTRICTIONS APPLY (UM,Sec.2.20 C &D).Any approved grading,digging or trenching beneath a tree canopy shall be performed using ‘air-spade’method as a preference,with manual hand shovel as a backup.For utility trenching,including sewer line,roots exposed with diameter of 1.5 inches and greater shall remain intact and not be damaged.If directional boring method is used to tunnel beneath roots,then Table 2-1,Trenching and Tunneling Distance,shall be printed on the final plans to be implemented by Contractor. 33.PLAN SET REQUIREMENTS.The final Plans submitted for building permit shall include the following Information and notes on relevant plan sheets: a.SHEETT-1,BUILDING PERMIT.The building permit plan set will include the City’s full-sized,Sheet T-1 (Tree Protection-it’s Part of the Plan!),available on the Development Center website at http://www.cityoftaloalto.org/civicax/filebank/documents/31783.The Applicant shall complete and sign the Tree Disclosure Statement and recognize the Project Arborist Tree Activity Inspection Schedule.Monthly reporting to Urban Forestry/Contractor is mandatory. (lnsp.#1:applies to all projects;with tree preservation report:lnsp.#1-7 applies) b.The Tree Preservation Report ITPR).All sheets of the Applicant’s TPR approved by the City for full implementation by Contractor,shall be printed on numbered Sheet T-1 fT-2,T-3,etc)and added to the sheet index. C.Plans to showprotective tree fencing.The Plan Set (esp.site,demolition,grading &drainage, foundation,irrigation,tree disposition,utility sheets,etc.)must delineate/show the correct configuration of Type I,Type It or Type Ill fencing around each Regulated Tree,using a bold dashed line enclosing the Tree Protection Zone (Standard Dwg.#605,Sheet T-1; City Tree Technical Manual,Section 6.35-Site Plans);or by using the Project Arborist’s unique diagram for each Tree Protection Zone enclosure. PUBLIC WORKS ENGINEERING CONDITIONS —Ajay Kumar ajay.kumar@cityofpaIoaIto.org The following shall be addressed prior to issuance of a Building Permit,Excavation and Grading Permit, Certificate of Compliance,Street Work Permit and/or Encroachment Permit. 34.DEMOLITION PLAN:Place the following note adjacent to an affected tree on the Site Plan and Demolition Plan:“Excavation activities associated with the proposed scope of work shall occur no closer than 10-feet from the existing street tree,or as approved by the Urban Forestry Division contact 650-496-5953.Any changes shall be approved by the same”. 35.GRADING PERMIT:Separate Excavation and Grading Permit will be required for grading activities on private property that fill,excavate,store or dispose of 100 cubic yards or mote based on PAMC Section 16.28.060.Applicant shall prepare and submit an excavation and grading permit to Public Works separately from the building permit set.The permit application and instructions are available at the Development Center and on our website. C V 2353 Webster St approval Individual Review 1SPLN 00339 Page9ofl2 V http ://www.cityofpaloa lto.org/gov/depts/pwd/forms and permits.asp 36.GRADING &DRAINAGE PLAN:The plan set must include a grading &drainage plan prepared by a licensed professional that includes existing and proposed spot elevations,earthwork volumes, finished floor elevations,area drain and bubbler locations,drainage flow arrows to demonstrate proper drainage of the site.Adjacent grades must slope away from the house a minimum of 2%or 5%for 10-feet per 2013 CBCsection 1804.3.Downspouts and splashblocks should be shown on this plan,as well as any site drainage features such as swales,area drains,bubblers,etc.Grading that increases drainage onto,or blocks existing drainage from neighboring properties,will not be allowed.Public Works generally does not allow rainwater to be collected and discharged into the Street gutter,but encourages the developer to keep rainwater onsite as much as feasible by directing runoff to landscaped and other pervious areas of the Site.See the Grading &Drainage Plan Guidelines for New Single Family Residences on the City’s website. http://www.cityofpaloalto.org/civicax/filebank/documents/2717 37.BASEMENT DRAINAGE:Due to high groundwater throughout much of the City and Public Work5 prohibiting the pumping and discharging of groundwater,perforated pipe drainage systems at the exterior of the ba5ement walls or under the slab are not allowed for this site.Adrainage system is, however,required for all exterior basement-level spaces,such as lightwells,patios or stairwells. This system consists of a sump,a sump pump,a backflow preventer,and a closed pipe from the pump to a dissipation device onsite at least 10-feet from the property line and 3-feet from side an rear property lines,such as a bubbler box in a landscaped area,so that water can percolate into the soil and/or sheet flow across the site.Include these dimensions on the plan.The device must not allow stagnant water that could become mosquito habitat.Additionally,the plans must show that exterior basement-level spaces are at least 7-3/4”below any adjacent windowsills or doorsills to minimize the potential for flooding the basement.Public Works recommends a waterproofing consultant be retained to design and inspect the vapor barrier and waterproofing systems for the basement. 38.BASEMENT SHORING:Shoring Plans prepared by a licensed professional are required for the Basement Excavation and shall be submitted with the Grading and Excavation Permit.Shoring for the basement excavation,including tiebacks,must not extend onto adjacent private property or into the City right-of-way without having first obtained written permission from the private property owners and/or an encroachment permit from Public Works. 39.The site drainage system that collects runoff from downspouts and landscape area shall be a separated from the pump system that discharges runoff from light wells.Plot and clearly label the two separate systems and including the separate outfalls for each system. 40.UTILITIES:Note that all above ground utilities,such as transformer,backflow preventer,gas meters, etc.,shall be located within project site but accessible from the street.Any new or relocated utilities will correspond with approved locations from City Utilities Department. 0 0 2353 Webster St.approval Individual Review I8PLN-00339 Page 10 of 12 41.GEOTECHNICAL REPORT:Shall clearly identify the highest projected groundwater level to be encountered in the area of the proposed basement in the future will be ______ feet below existing grade.Provide the following note on the Final Grading Plans.“In my professional judgement,the highest projected groundwater level to be encountered in the area of the proposed basement in the future will be _______ feet below existing grade.As a result,the proposed drainage system for the basement retaining wall will not encounter and pump groundwater during the life of this wall.” 42.DEWATERING:Excavation may require dewatering during construction.Public Works only allows groundwater drawdown well dewatering.Open pit groundwater dewatering is not allowed. Dewatering is only allowed from April through October due to inadequate capacity in our storm drain system.The geotechnical report for this site must list the highest anticipated groundwater level.We recommend that a piezometer be installed in the soil boring.The contractor shall determine the depth to groundwater immediately prior to excavation by using a piezometer or by drilling and exploratory hole.Based on the determined groundwater depth and season the contractor may be required to dewater the site or stop all grading and excavation work.In addition Public Works may require that all groundwater be tested for contaminants prior to initial discharge and at intervals during dewatering.If testing is required,the contractor must retain an independent testing firm to test the discharge water for contaminants Public Works specifies and submit the results to Public Works. Public Works reviews and approves dewatering plans as part of a Grading Permit and Dewatering Permit.The applicant can include a dewatering plan in the building permit plan set in order to obtain approval of the plan during the building permit review,but the contractor will still be requited to obtain a Grading Permit prior to dewatering.Alternatively,the applicant must include the above dewatering requirements in a note on the site plan.Public Works has dewatering guidelines available at the Development Center and on our website. http://www.cityofpaloalto.org/gov/depts/pwd/forms_and_permits.asp 43.WATER FILLING STATION:applicant shall install a water station for the non-potable reuse of the dewatering water.This water station shall be constructed within private property,next to the right- of-way,(typically,behind the sidewalk).The station shall be accessible 24 hours a day for the filling of water carrying vehicles (i.e.street sweepers,etc.).The water station may also be used for onsite dust control,Before a discharge permit can be issued,the water supply station shall be installed, ready for operational and inspected by Public Works.The groundwater will also need to be tested for contaminants and chemical properties for the non-potable use.The discharge permit cannot be issued until the test results are received.Additional information regarding the station will be made available on the City’s website under Public Works. 44.WORK INTHE RIGHT-OF-WAY:The plans must clearly indicate any work that is proposed in the public right-of-way,such as sidewalk replacement,driveway approach,or utility laterals.The plans must include notes that the work must be done per City standards and that the contractor performing this work must first obtain a Street Work Permit from Public Works at the Development Center.If a new driveway is in a different location than the existing driveway,then the sidewalk 0 2353 Webster St.approval Individual Review 18PLN-00339 Page 11 of 12 associated with the new driveway must be replaced with a thickened (6”thick instead of the standard 4”thick)section.Additionally,curb cuts and driveway approaches for abandoned driveways must be replaced with new curb,gutter and planter strip. 45.Provide the following note on the Site Plan and adjacent to the work within the Public road right-of- way.“Any construction within the city’s public toad right-of-way shall have an approved Permit for Construction in the Public Street prior to commencement of this work.THE PERFORMANCE OF THIS WORK IS NOT AUTHORIZED BYTHE BUILDING PERMIT ISSUANCE BUT SHOWN ON THE BUILDING PERMIT FOR INFORMATION ONLY.” 46.Provide the following note on the Site Plan and Grading and Drainage Plan:“Contractor shall not stage,store,or stockpile any material or equipment within the public road tight-of-way.” Construction phasing shall be coordinate to keep materials and equipment onsite. 47.SIDEWALK,CURB &GUTTER:As part of this project,the applicant shall replace those portions of the existing sidewalks,curbs,gutters or driveway approaches in the public right-of-way along the frontage(s)of the property.Contact Public Works’inspector at 650-496-6929 to arrange a site visit so that the inspector can discuss the extent of replacement work along the public road.The site plan submitted with the building permit plan set must show the extent of the replacement work. The plan must note that any work in the tight-of-way must be done per Public Works’standards by a licensed contractor who must first obtain a Street Work Permit from Public Works at the Development Center.Provide site direction sheet obtained from PW inspector in plan set. 48.Any existing driveway to be abandoned 5hall be replaced with standard curb &gutter.This work must be included within a Permit for Construction in the Public Street from the Public Works Department.A note of this requirement shall be placed on the plans adjacent to the area on the Site Plan. 49.IMPERVIOUS SURFACE AREA:The project will be creating or replacing 500 square feet or more of impervious surface.Accordingly,the applicant shall provide calculations of the existing and proposed impervious surface areas with the building permit application.The Impervious Area Worksheet for Land Developments form and instructions are available at the Development Center or on our website. 50.PUBLIC WORKS STANDARDS CONDITIONS:The City’s full-sized “Standard Conditions”sheet must be included in the plan set.Copies are available from Public Works on our website: http://www.cityofpaIoalto.org/civicax/filebank/blobdload.aspx?t67;75.06&Blobl D=6626 1 51.STORM WATER POLLUTION PREVENTION:The City’s full-sized “Pollution Prevention -It’s Part of the Plan”sheet must be included in the plan set.Copies are available from Public Works on our website http://www.cityofpallto.org/civicax/fllebank/documents/2732 0 0 2353 Webster St.approval ndlvidual Review 8PLN-00339 Page 120112 52.This project triggers the California Regional Water Quality Control Board’s revised provision C.3 for storm water regulations (incorporated into the Palo Alto Municipal Code,Section 16.11)that apply to residential land development projects that create or replace between 2,500 and 10,000 square feet of impervious surface area.The applicant must implement one or more of the following site design measures on the grading and drainage plan: •Direct roof runoff into cisterns or rain barrels for reuse. •Direct roof runoff onto vegetated areas. •Direct runoff from sidewalks,walkways,and/or patios onto vegetated areas. •Direct runoff from driveways and/or uncovered parking lots onto vegetated areas. •Construct sidewalks,walkways,and/or patios with permeable surfaces. •Construct driveways,and/or uncovered parking lots with permeable surfaces 53.Provide the following as a note on the Site Plan:“The contractor may be required to submit a logistics plan to the Public Works Department prior to commencing work that addresses all impacts to the City’s right-of-way,including,but not limited to:pedestrian control,traffic control,truck routes,material deliveries,contractor’s parking,concrete pours,crane lifts,work hours,noise control,dust control,storm water pollution prevention,contractor’s contact,noticing of affected surrounding properties,and schedule of work.The requirement to submit a logistics ptan will be dependent on the number of applications Public Works Engineering receives within close proximity to help mitigate and control the impact to the public-right-of-way.If necessary,Public Works may require a Logistics Plan during construction.” End Project Conditions 124-05-037 124-05-038 124-05-033 124-05-060 124-05-061 132-01-085 132-01-074 124-05-018 124-05-034 4-05-041 124-05-040 124-05-039 124-05-059 124-05-035 124-05-036 124-05-019 124-05-032 132-01-084 132-01-072 132-01-082 124-05-017 124-05-016 T O R E GON A VE NU E O R E G O N E X P R ESS W A Y G O R E GON A VE NU E 584 5 586 586 2330 2330 2397 2397 2371 371 2360 2370 2370 2370A 555 555 2343 2343 2353 2353 2333 333 2350 2350 615 615 2360 2360 609 609 2320 613 613 604 604 618 612 612 234 2361 2361 2375 2375 9 685 685A 6 5 0 This map is a product of the City of Palo Alto GIS This document is a graphic representation only of best available sources. Legend Assessment Parcel Palo Alto Assessment Parcel Palo Alto Assessment Parcel Outside Palo Alto abc Road Centerline Small Text (TC) Curb Face (RF) Pavement Edge (RF) abc Address Label (AP) Current Features 0' 69' Attachment D: Location Map 2353 Webster Street 18PLN-00339 CITY O F PALO A L TO IN C O R P O R ATE D C ALIFOR N IA P a l o A l t oT h e C i t y o f A P RIL 16 1894 The City of Palo Alto assumes no responsibility for any errors ©1989 to 2016 City of Palo Alto efoley2, 2020-04-24 09:22:49Assessor Parcels (\\cc-maps\Encompass\Admin\Meta\View.mdb) UPDATED: February 26, 2020 1 Regulations for Groundwater Dewatering during Construction of Below Ground Structures A How-to Guide to Meeting City of Palo Alto Dewatering Requirements I. BACKGROUND In recent years, concerns that temporary construction-related groundwater dewatering may be wasting water, potentially damaging structures, trees and vegetation, and depleting or altering the flow of groundwater, have arisen. In response, the City of Palo Alto (City) established new requirements in February 2016 designed to minimize and standardize the process of pumping and discharge of groundwater from dewatering of below ground structures (e.g., basement or parking garage) during construction. After the results of new groundwater dewatering regulations from the 2016 and 2017 Construction Seasons, the City Council approved several enhancements to the dewatering policy that were codified in the Palo Alto Municipal Code and went into effect in May 2017, and again in December 2017 (Attachment 1). The 2017 changes included improving Fill Station performance, monitoring actual groundwater elevation changes during assessing impacts on nearby structures, clarifying reporting requirements, and a Hydrogeological Study (Study). This guide provides further explanation regarding the most recent code changes (which became effective on February 21, 2018) and is intended to assist project applicants in meeting code requirements. II. GENERAL GROUNDWATER DEWATERING REQUIREMENTS Note that this document is in reference to temporary groundwater dewatering during construction of below ground structures. This document does not contain information regarding dewatering of existing below ground structures in the City of Palo Alto. Temporary construction-related groundwater dewatering (dewatering) may be conducted using 1) groundwater exclusionary techniques (e.g., secant or cut-off walls), or 2) controlled groundwater pumping, also known as drawdown well dewatering. The City’s Public Works Department (Public Works) does not allow open pit dewatering of groundwater during construction; however, it may be allowed, if water quality limits are met, for removal of rainwater if it has accumulated at the bottom of an excavation site. If rainwater dewatering is required, the project manager/applicant must contact the City’s Watershed Protection Group at (650) 329-2122 before discharging to the City’s storm drain system. Attachment 2 provides applicants a basic flow chart to understand the City’s compliance process regarding the two types of allowed construction dewatering. To assist the City in determining whether dewatering will likely be required in the construction of below ground structures, the project applicant must submit a Geotechnical Report, also known as a soils report, (separate from the Hydrogeological Study described below) prior to the Building Permit application. In addition, if the deepest excavation will be within five feet of the anticipated groundwater level stated in the Geotechnical Report, the contractor must determine the depth to groundwater immediately prior to submittal of the Excavation and Grading Permit. It is recommended that the boring hole for this depth measurement be protected and maintained and used as the monitoring well for the dewatering operations. UPDATED: February 26, 2020 2 As discussed later in this document, all dewatering sites are required to install a monitoring well onsite at the farthest feasible point from the underground structure. Placing this boring correctly and protecting it may avoid future work. If groundwater is found to be within two feet of the deepest excavation, a drawdown well dewatering system or cutoff wall must be installed. Regardless of this testing, if groundwater is actually encountered during construction (and the applicant does not have a dewatering permit), the contractor must immediately stop all work and must meet all of the following requirements prior to resuming work. The City’s dewatering season is April 1 through October 31 due to the capacity of the City's storm drain system. Dewatering to the sanitary sewer system is prohibited, exceptions may be allowed only under special circumstances and with a discharge permit obtained through Public Works’ Watershed Protection Group. During the dewatering season, sites will be allowed to dewater for a 12-week time period, including a two-week start-up period. The two-week start-up period is intended to provide adequate time for the contractor to meet the City’s dewatering requirements as well as City staff to inspect and monitor the dewatering start-up operation. At the end of the two-week start-up period, compliance with all performance standards and water quality standards, the hydrogeological study data, shall be demonstrated in order to continue dewatering. Residential sites are expected to complete dewatering within the allotted time period. Dewatering beyond 12 weeks is allowed only under special circumstances and if approved by the City Engineer. The City will consider allowing groundwater discharges to occur (to the storm drain system) from November 1 to March 31 if the applicant can provide sufficient evidence that the receiving storm drain line and water body has sufficient capacity to accommodate a 10-year, 6-hour storm event in addition to the dewatering discharge (a pipe capacity calculation). Where dewatering is required, applicants shall conduct dewatering in full compliance with the provisions of Chapter 16.28 (Excavation, Grading and Fills) as well as Chapter 9.10 (Noise) of the City’s Municipal Code, the regulations in this guide, and other permit conditions established by City staff. Due to the complexity of dewatering projects, City staff may impose and enforce additional requirements when or after a permit is issued in order to ensure public safety, ensure the condition of its infrastructure, or to protect the water quality of downstream water bodies. During the period of construction and dewatering discharge, project applicants/permittees are expected to promptly implement actions identified and required by City staff, including, but not limited to, notices of non-compliance and directives requiring immediate cessation of discharge. Administrative penalties may be put into effect for sites not in compliance with any of the City requirements, and will accrue if the applicant does not comply as requested by the City. A cessation order may be issued for reasons including, but not limited to: capacity issues in the storm drain or sanitary sewer systems; storm drain or sanitary sewer system failures; excess flow entering the Palo Alto Regional Water Quality Control Plant, including exceptional storm events; emergency or routine maintenance of City infrastructure; protection of the environment, public health, safety and welfare; and failure to follow the terms/conditions/requirements of any permit. UPDATED: February 26, 2020 3 NOTE: All information contained in the dewatering permit application, dewatering permit, supporting documents, and the associated street work permit will be made available to the public upon request. III. GROUNDWATER EXCLUSIONARY TECHNIQUE REQUIREMENTS If the rate of groundwater discharge is greater than thirty gallons per minute for residential sites, groundwater exclusionary techniques cannot be used, and the requirements of Subsections IV (below) shall be followed. When groundwater exclusionary techniques are utilized, applicants must submit to the City a Dewatering Permit – Groundwater Exclusionary Technique packet with a Grading and Excavation Permit application (after Planning entitlement is approved). The Grading and Excavation Permit for a project will not be issued until all required submittals related to dewatering have been submitted, reviewed and approved by Public Works Engineering staff. The (Exclusionary Techniques) Dewatering Packet (Attachment 3) shall include the following: 1) Exclusionary Technique Permit form, 2) Exclusionary Technique plan, and 3) Inspection Checklist. Groundwater exclusionary techniques shall be conducted in compliance with the following: A. The rate of discharge of groundwater shall be limited to thirty gpm or less for residential dewatering projects. B. The Dewatering Plan shall be followed at all times and shall consist of a plan view of the project site and include all required features of the dewatering operation such as but not limited to: metered settling tank and it’s safely accessible location onsite, monitoring well at the farthest feasible onsite point from the excavation, location and size of percolation pits, pump location/s, associated piping, and stabilized construction entrance. C. Groundwater Use Plan shall illustrate how the groundwater will be used to the maximum extent practicable and without discharge to the storm drain system. When feasible, the primary focus of discharge shall be to percolate the discharge onto the construction property, usually into percolation pits. A secondary method of discharge should be to percolate the groundwater onto adjacent neighbor properties upon their permission (this should be handled between the project applicant and the property owners without facilitation or further approval from the City). Finally, the groundwater may be trucked offsite and, in coordination with the City’s Urban Forestry and/or Parks and Recreation staff, distributed throughout the City to locations that can use the water. D. The applicant shall install a groundwater monitoring well at the site. It shall be located at the farthest feasible onsite point from the underground structure. Initial groundwater level results must be included in the dewatering plan (same data point as the one required prior to grading and excavation permit application). E. Project status reporting: During the construction period of the underground structure, the applicant must submit periodic groundwater level reports and have the data available per request. At minimum, monitoring well data shall be collected daily for the first two weeks beginning with the start of the excavation UPDATED: February 26, 2020 4 activity and weekly thereafter. A final report shall be submitted two weeks after pumping of residual water ceases. All status reports should be submitted to Public Works Engineering (PWE) staff at the Development Center, email to the PWE staff person reviewing the project is preferred. Questions should be directed to pwecips@CityofPaloAlto.org. NOTE: Administrative Penalties may be imposed upon failure to follow the required reporting frequency. IV. CONTROLLED GROUNDWATER PUMPING (WITHOUT A SECANT OR CUT-OFF WALL) REQUIREMENTS When controlled groundwater pumping techniques are utilized, applicants must submit to the City a Dewatering Permit – Controlled Groundwater Pumping Packet with the Excavation and Grading Permit and Street Work Permit applications (after Planning entitlement is approved). The Excavation and Grading permit for a project will not be issued until all required submittals have been received, reviewed, and approved by PWE staff. A Dewatering Permit must be obtained before any discharge from the site occurs. Note that for residential projects, the Excavation and Grading Permit is only issued concurrently with the Building Permit. While discharging to the storm drain system, construction work on the underground structure shall be continuous and occur daily (in accordance with approved work hours). The contractor shall make progress towards completion of the underground structure without delay and following the detailed construction schedule provided in the Excavation and Grading Permit and/or the Dewatering Permit packet. In addition to what is required for exclusionary techniques (aside from the cut-off wall itself and the 30 gpm limitation), a Hydrogeological Study and an in-depth Groundwater Use Plan must also be submitted. Refer to the Controlled Groundwater Pumping Dewatering Permit Packet in Attachment 4 for more information. The following provides additional details regarding the City’s controlled groundwater pumping requirements: HYDROGEOLOGICAL STUDY REQUIREMENTS HAVE CHANGED: Public Works will no longer accept the use of “single layer models” to analyze subsurface soil condition of a particular parcel or project site where an underground structure is proposed and where dewatering is required. A “single layer model” is defined as any calculation, computer program or other method, which models the composition and/or properties of subsurface soils as a single, homogeneous layer of material. Site specific tests shall be performed to generate data in order to model the subsurface soil properties and produce a more accurate, site-specific, model. Additional information is detailed below. As with exclusionary techniques, the applicant shall install a groundwater monitoring well on the construction site at the farthest feasible point from the underground structure. Initial groundwater level results must be included in the Hydrogeological Study. During the construction period of the underground structure, the applicant must submit frequent groundwater level reports and have the data available per request. At minimum, monitoring well data shall be conducted daily for the first two weeks of the 12-week period and weekly UPDATED: February 26, 2020 5 thereafter. At the end of the two week start-up period, or thereafter, if drawdown results are greater than anticipated, the applicant shall submit a revised Dewatering Hydrogeological Study and any revised conclusions on impacts of the groundwater drawdown. A. Dewatering Hydrogeological Study - The purpose of this Study is to determine the initial, pre-construction groundwater levels as well as the impacts of groundwater pumping on the site and surrounding area. The Study should include the radius of influence (i.e. extent of cone of depression) from each dewatering well (if more than one is installed on-site) as a function of time, based on local soil and groundwater conditions. The Hydrogeological Study shall demonstrate that the dewatering plan has been designed to the maximum extent practicable to minimize the volume of water pumped during the dewatering operation, the flow rate, and the duration of the pumping. The Study shall be stamped by a California licensed Hydrogeologist or California licensed Geotechnical Engineer and submitted to the City as part of the Dewatering Packet. The Study should also include the following items: i. A minimum of 4 borings or other subsurface tests (Cone Penetrometer Tests, CPTs, are preferred) shall be performed across the project site/excavation area by a California licensed Geotechnical Engineer in order to develop a multilayer model of the subsurface soil conditions and properties. The tests should be performed to a depth of no less than 30 feet below existing grade (for residential projects). The test data shall be used to create a multi-layer model of subsurface conditions; single-layer models which model site conditions as a homogenous layer will not be accepted. 1. The data shall be used to design a dewatering plan based on the subsurface conditions/strata which results in the minimization of pumped water to the maximum extent practicable. 2. Well depth shall be specified based upon the subsurface conditions. 3. The pump depth within the dewatering well shall be specified based on the subsurface conditions and required drawdown. ii. A description and cross section(s) of the cone(s) of depression of any on- site monitoring well(s) as well as any nearby dewatering sites within a 400-foot radius of the property that may interact with or be influenced by the dewatering activity at the site. The location of the monitoring well(s) and nearby sites should also be shown on a map. iii. Anticipated drawdown curve and pumping flow rate. A description and cross section(s) of the cones of depression of the dewatering wells shall be calculated and graphed. The predicted drawdown level (depth to groundwater) at the onsite monitoring well shall be shown as a function of time; accurately graphed cross sections with data points or tabular data format shall be provided. The anticipated pumping flow rate shall be calculated for the dewatering system as well as the total volume due to be pumped for the 12 week dewatering period and daily totals. UPDATED: February 26, 2020 6 1. NOTE: The depth of each dewatering well pump will be verified in the field once installed and prior to any dewatering operations. iv. Using extrapolated data from the drawdown curves, determine the pumping rates needed to achieve the following drawdown performance: Prior to pouring a basement slab, groundwater may be pumped no deeper than three feet below the depth of the slab, measured at the center. After the slab is poured, groundwater may be pumped no deeper than one foot below the center. These values can be extrapolated using the (verified) drawdown curves and the on-site monitoring well data points. B. Groundwater Use Plan (Plan) shall demonstrate how the pumped groundwater will be used to the maximum extent practicable. Two required components of this plan are the 1) groundwater flow meter and sediment settling tank system and 2) the Fill Station. Both components must be inspected and approved by City staff before obtaining a Controlled Groundwater Pumping Dewatering Permit. Inspections and approvals are documented via the Inspection Checklist (Attachment 4), which must be signed by a Public Works Inspector prior to issuing the Grading Permit, Dewatering Permit, Street Work permit, and associated Building Permit; no Dewatering Permit will be issued without a Public Works Inspector–signed Checklist. At a minimum, the Plan should include the items below; however, the applicant should be creative in their plan to use the pumped groundwater and shall adhere to the Plan throughout the dewatering period: i. Groundwater flow meter and sediment settling tank system: 1. Provide an accurate, non-mechanical flow meter with a data logger in good working condition at the inlet of the tank. The flow meter shall be positioned in a location which is safely accessible by City inspectors on a regular basis. Both flow rate and total flow measurements shall be easily readable and set to gallons. Before any water is pumped, the initial flow meter reading shall be checked and verified by the Watershed Protection Inspector (WP Inspector) as part of the initial dewatering Inspection Checklist approval process. The WP Inspector will collect meter readings on a daily basis during the two-week start-up period and weekly thereafter; the contractor is required to also monitor and record the meter readings using the same frequency. a. The area surrounding the tank should be kept clear at all times, with a safe pathway to the meter and tank. b. The edge of the tank should not be at the edge of the excavation area, as it may lead to unsafe conditions. c. The contractor shall contact PW Inspection prior to changing or replacing any meter. d. The point of outlet on the settling tank cannot be at the bottom of the settling tank. e. The settling tank must have a discharge valve which can be locked in a closed position. PW or WP Inspectors will UPDATED: February 26, 2020 7 lock the discharge valve to ensure that the erroneous discharge does not occur and that the City is notified and aware of exactly when discharge begins. Further sections below explain this process in greater detail. 2. Design the tank system so that the storage tank is always at minimum one-half full during the entire dewatering period to facilitate water truck usage. 3. Prior to the start-up period and as part of the Inspection Checklist process, once the tank is at least half-full and before any discharge of groundwater occurs, contact Watershed Protection at (650) 329-2122 for an initial inspection and for water quality testing. For non-(contaminated) plume areas, basic measurements will generally include pH, conductivity and turbidity. 4. After the WP Inspector collects water quality samples and provides a clearance that the sample is within acceptable limits, the contractor will contact the WP Inspector to temporarily unlock the tank discharge valve to allow the tank to be drained to the property while waiting to obtain the Dewatering Permit Packet from Public Works Engineering. Consult the WP Inspector for assistance. Provide a screen or other covering over the tank for mosquito management. City staff may require the use of Bacillus thuringiensis israelensis (Bti), a naturally occurring soil bacterium that effectively kills mosquito larvae, if necessary. ii. A Fill Station shall be constructed to provide the City and nearby residents and business owners the opportunity to use the pumped groundwater and to minimize the amount discharged to the storm drain system. The Fill Station should include two methods for water distribution: a truck-filling outlet for water truck distribution to sites in the City and a fill-up outlet, or hose bibbs, for neighboring properties. Detailed information about the fill station and its components is listed below. When the Fill Station is ready, contact Public Works Engineering Inspection staff (PWE Inspector) at (650) 496-6929 for an inspection of both the Fill Station and settling tank system and contact Building Inspection staff at (650) 444-6173 for an Electrical Safety Check. (Inspectors must check off these items on the Inspection Checklist.) The following is required for the Fill Station: 1. Location and set-up: • Locate the Fill Station outside the site construction fence to allow 24-hour access. The construction site should be locked outside of normal construction hours. • A lock is not required at the Fill Station, but if the applicant deems it necessary, a combination lock should be used with the combination of 2, 4, 6, 8 (or other easily UPDATED: February 26, 2020 8 remembered combination and shared with City Inspectors). • Truck fill outlet: provide a 2.5-inch hydrant fitting hose connection with a 50-foot traffic-rated hose. • Neighboring properties fill outlet: provide at least two 100-foot (minimum) hoses arranged on reels and connected to standard hose bibs. Hose bibs shall produce a minimum of 10gpm at the end of each 100 foot hose simultaneously. The applicant shall allow adjacent properties to use hoses connected to the fill station(s). Hoses shall be placed in a manner that is safe to the public and does not cause damage to neighboring or City property. Hoses shall not cross the street. The City may modify these requirements as circumstances require. • As with the tank system, the fill station shall include accurate and safely accessible, non-mechanical flow meters with data loggers in good working condition at the outlet point of the Fill Station to log water reuse. Both flow rate and total flow measurements shall be easily readable and set to gallons. The initial flow meter reading should be noted before any water is pumped. Flow meter reading shall be checked and verified by the PWE or WP Inspector as part of the initial dewatering approval process, Inspection Checklist. The WP Inspector will collect Fill Station meter readings on a daily basis during the two- week start-up period and weekly thereafter; the contractor is required to also monitor and record the meter readings using the same frequency. • Supply log sheets and a pen for truck drivers to log the truck company, date, and amount of each fill-up. • The temporary power source needed for the Fill Station should be placed inside the construction site (and NOT in the Fill Station), if possible. If needed, a switch with an in- use cover to power on the Fill Station pump may be placed inside the fill station cabinet. An additional switch with an in-use cover for the truck-fill hose pump should be provided. Both switches should be clearly labeled. • Provide easy-to-read signage for the Fill Station (including “Do not Drink”) and directions explaining how to use it. • For the hose bibs, provide signage that reads "No Hoses Crossing Street, Sidewalk, or Private Properties." 2. The applicant must demonstrate maximum 10-minute fill time for a ~2700 gallon water truck as part of the Inspection Checklist signoff. 3. Prior to the commencement of dewatering activities, the applicant shall notify occupants of neighboring properties of the temporary availability of water. Contact Public Works Engineering UPDATED: February 26, 2020 9 staff (650 329-2496, Option 8) for copies of door hangers to be used for notification. Door hangers not collected/received by the residents must be removed after 24 hours. iii. Irrigation of sites: The applicant is responsible for having the pumped groundwater delivered to nearby sites as directed by the City. The applicant shall contract with or otherwise provide water truck service; the water truck operator/company shall contact the City’s Urban Forestry staff should be contacted by the truck service company at (650) 496-5986 to determine the location of sites to be irrigated. During the first six weeks of dewatering activities (not including the two-week start-up period), water should be trucked one full day (8 hours) per week from the project site to the irrigation sites. This shall increase to five days per week (8 hours per day) during the remaining 4 weeks of the dewatering period. iv. On-site Use of Groundwater: Pumped groundwater should be used on the construction site as needed and whenever possible. This includes controlled infiltration, irrigation of existing landscaping, dust suppression and other construction needs. C. A Pre-construction Building Condition Survey and Report of structures located on adjacent parcels prepared by a licensed surveyor and meeting City standards must be submitted, reviewed, and approved prior to obtaining a dewatering permit. The survey must be prepared by a California licensed surveyor whereas the photographic and narrative report may be prepared by the applicant. Both documents shall be submitted at the same time as one report. The applicant is responsible for obtaining permission from neighboring property owners to enter their property to take survey points of the building interior. If permission is not granted, City staff should be notified; however, interior survey points are not required in order to obtain a Dewatering Permit. The survey shall include a photographic and narrative report on the external condition of each structure as well as surveyed and marked elevations of adjacent parcels, with particular attention to the condition of concrete foundations, structural connections, brickwork, plasterwork and other architectural finishes that are susceptible to cracking. The report shall assess the likelihood that the proposed dewatering would cause effects (including but not limited to settlement or movement) on off- site private or public structures or infrastructure, including the right-of-way, easements, and utilities within public utility easements, and the health or viability of vegetation or trees. To the extent that the report concludes that off-site effects are reasonably likely to occur, the applicant shall identify avoidance measures to be implemented that will minimize the type and severity of those effects and shall develop a monitoring plan to assess any actual effects on vegetation, trees, structures and infrastructure. D. A pipe capacity calculation is required. This calculation shall show that the storm drain inlet to which the dewatering water is proposed to be discharged to can accommodate the anticipated dewatering discharge in addition to a 10-year, 6 hour storm event. PW Engineering can assist in providing the appropriate storm UPDATED: February 26, 2020 10 drain staff for assistance. NOTE: If the pipe capacity analysis determines that the storm drain discharge point cannot accommodate the dewatering flow in addition to the 10 year, 6 hour, storm event, a Dewatering permit CANNOT be issued the day-of or after the date which is 12 weeks prior to October 31st. In other words, dewatering cannot begin within 12 weeks of October 31st. E. A detailed construction schedule must be included in the dewatering permit application packet. This schedule shall detail construction phases such as, but not limited to: a. Equipment mobilization b. Shoring installation c. Dewatering plan setup d. Excavation activity e. Dewatering start f. Finished excavation g. Basement construction – base rock, rebar, forms, plumbing, concrete, waterproofing, etc. h. Backfill i. Dewatering end The construction schedule shall list the duration of each step in days/weeks and total the number of weeks between Dewatering start and Dewatering end. F. A Dewatering Regulation Acknowledgement Statement must be signed by the property owner/s and licensed contractor and shall accompany the dewatering application. G. Contractor is required to begin shoring installation and excavation once the Excavation and Grading permit is issued and PRIOR to any dewatering operations. In order to minimize the volume of groundwater discharged to the storm drain and to maximize the 12 week allowable dewatering period, the dewatering system may ONLY be turned on once the excavation has encountered water or reached a depth within 2 feet of where groundwater is located based on the current monitoring well measurement at that time. The contractor is required to contact PW Inspection or WP Inspection prior to dewatering operation startup to unlock the settling tank discharge valve. Once the discharge valve is unlocked, the contractor must IMMEDIATELY obtain the dewatering permit from PW staff at the Development Center. If the dewatering permit is not immediately obtained on the same day the discharge valve is unlocked, PW will revoke the Excavation and Grading permit and daily administrative penalties may apply. H. STARTUP of dewatering operations is limited to Monday through Thursday ONLY. UPDATED: February 26, 2020 11 Dewatering may NOT start Friday through Sunday. I. Upon dewatering shutdown, the settling tank meter shall remain in place until City staff have recorded the final meter reading; PW or WP inspection should be contacted to record the meter reading. J. Verify the anticipated drawdown curve with a pump test performed on monitoring well(s) installed on the project site. Though the City is not currently requiring a particular type of pump test, the type used should be authorized and approved by a California licensed Hydrogeologist or CA licensed Geotechnical Engineer. Using the pump test and any other relevant data, the report shall state the anticipated pumping flow rate as well as the total amount of water due to be pumped for the 12 week dewatering period; daily pumped totals shall also be included. Following the two-week start-up period, the dewatering, pumping rates and maximum amount of water pumped on a daily basis shall be limited to the values calculated in the verification study. F. Project status reporting: During the construction period of the underground structure, the applicant must submit periodic reports and have the data available per request. Report contents and submittal frequency requirements are listed below. All status reports should be submitted via email to the Public Works Engineering staff who has been working on your project and who issued the Excavation and Grading permit. Questions should be directed to pwecips@CityofPaloAlto.org. 1) Monitoring well levels: At minimum, monitoring well data shall be collected daily for the first two weeks (start-up period) of the 12-week period and weekly thereafter. Status reports should be submitted weekly during start-up period and monthly thereafter. A final report shall be submitted two weeks after pumping ceases. 2) Flow meter readings: At minimum, flow meter data shall be collected daily for the first two weeks (start-up period) of the 12-week period and weekly thereafter. Status reports should be submitted weekly during start-up period and monthly thereafter. A final report shall be submitted two weeks after pumping ceases. 3) Survey data (see subsection IV.C. above): Once dewatering commences, survey data should be collected and reported weekly during the two-week start-up period and monthly thereafter. Note that the information will be made available to the public upon request. G. The Contractor and/or Applicant is required to contact PW Inspection to obtain the final meter readings once groundwater discharge has finished and prior to dismantling any dewatering system components. UPDATED: February 26, 2020 12 V. ADDITIONAL REQUIREMENTS FOR TEMPORARY CONSTRUCTION-RELATED GROUNDWATER DEWATERING IN GROUNDWATER (CONTAMINATED) PLUME AREAS Certain areas in the City have contaminated groundwater plumes due to previous land use. To determine if a site is in or nearby one of these areas, refer to the Attachment 5 figure. Dewatering sites in these areas must be carefully managed to ensure pumped groundwater does not enter the City’s storm drain system nor that it is used by members of the public without being treated. Therefore, Fill Stations are not required at these sites. However, the same flow meter/data logger requirements described in Section IV (B.i.) shall still be followed in order to account for the amount of groundwater pumped from the site. Construction of below ground structures in these areas triggers treatment requirements (in addition to sediment settlement) before discharging to the City’s storm drain system in order to protect the water quality of downstream creeks and the SF Bay. Because of site complexities, specific requirements may vary site by site. Therefore, for any site in or within 500 feet of the edge of a plume, contact the City’s Watershed Protection Group at (650) 329-2122 for guidance and requirements on sampling, treatment and disposal of temporary construction-related groundwater. Sampling groundwater for contaminants prior to initial discharge will be required, and potentially at intervals during dewatering. For all required sampling, the contractor must retain an independent testing firm to collect and process samples. Finally, the applicant should contact the Regional Water Quality Control Board (Water Board) to ensure additional state agency requirements are met. Note that compliance with the City does not imply compliance with the Water Board. Page 1 of 8 Development Review - Department Comments City Department: Planning Staff Contact: Arnold Mammarella (Consulting Architect) Date: 10/3/2019 Project Address/File #: 2353 Webster Street; 18PLN-00339 A. Staff has reviewed the revised plans for the proposed new two-story house filed on August 26, 2019 for compliance with the Palo Alto Single-Family Individual Review Guidelines. The revised plans are the third submittal with this application. Plans were initially filed on October 4, 2018. Following staff level review along with neighborhood input revised plans were filed on June 6, 2019. Additional neighbor comments were provided on those plans as well as staff review comments. The following content summarizes general information and the Individual Review Evaluation as related to meeting the Individual Review Guidelines for the Planning entitlement approval. Some content may be reiterated from the initial evaluation dated 11/13/18 or from staff comments on revised plans. General Information: There are five Individual Review Guidelines: 1. Site planning for driveway, garage and house, 2. Neighborhood compatibility for height, mass, and scale, 3. Resolution of architectural form, massing, and rooflines, 4. Visual character of street facing facades and entries, and 5. Privacy from second floor windows and decks. For approval, proposals need to be consistent with all five guidelines. The review considers the proposal’s response to each guideline’s approval criterion statement and whether the “key points” associated with each guideline have been followed. Guideline illustrations are also used when helpful to make interpretations in the evaluation. Please see the City’s illustrated guideline booklet if you have questions about the intentions of these regulations. Site and Neighborhood Context The property is located on northeast side (Bay side) of Webster Street one property in from the Oregon Avenue intersection. This block of Webster Street extends between Oregon Avenue to North California Avenue with approximately 23 properties along the street for this block (11 on this side of the street and 12 on the southwest side of the street). Most homes along this side of the street on this block appear to be early ranch style homes with sprawling footprints and low pitch gable or hip roof forms. There are also a couple of cottage style homes with moderate to steep roof pitches. In these homes the second floor is set within the roof form so that building walls are 1 story tall except at gables. Across the street there are numerous two-story homes of mostly modest scale with mixed one and two-story massing along with some one-story homes. Homes on the abutting lots and directly across the street are one- story. Generally, this end of the block has a modest scale to the streetscape featuring homes with mostly horizontal proportions, simple low pitch hip and gable rooflines and traditional materials and detailing. The subject lot is 72 feet wide by 110.4 feet deep, which is similar in shape and dimension to other nearby lots along this side of Webster Street. Lots across the street, excepting the larger corner lot, tend to be similar in depth but narrower at 60 feet in width. There are very large lots to the rear on Byron Street. The existing house built in 1926 has a T-shape footprint—wide facing the street and narrow extending to the rear setback line near the 77-inch diameter oak tree. The site plan configuration leaves a large southeast facing yard area as the home’s primary exterior yard space. This site planning pattern is common for one-story homes along this side of the street (i.e. large or usable yards oriented to the southeast side lot line). Some homes have southeast side yards in combination with large rear yards with two homes having the more traditional front-back yard configuration with narrow, not used side yards. The existing front yard setback is 24 feet, which seems similar to adjacent homes. Other than the existing house, the main site feature is the large oak tree situated in the middle of the rear yard setback with a canopy covering most of the rear half of the lot. The tree is close to the rear wall of the existing house and its canopy extends over much of the existing home’s roof. There are also two street trees within a deep street side planting strip and a few smaller trees on the lot. The street edge is a rolled curb. Public Comment Four neighbors wrote to express concerns or objections to the initial proposed design. They include neighbors on directly abutting lots to each side and the lot directly across the street. One of the issues of concern is the basement in terms of dewatering and possible impacts on adjacent structures and trees. The Individual Review Guidelines do not evaluate these impacts directly although site planning does consider existing homes and large trees as part of the context to preserve as well as patterns of site development in the neighborhood. This review would seek input from the project arborist and Public Work’s Urban Forestry as to possible impacts of basement construction and location on existing regulated trees, including how close the house and basement may be placed relative to existing trees. Otherwise, here are key points of neighbor comments: • 2397 Webster Street neighbor: Impact of basement excavation on large tree as well as neighbor’s large cedar tree. Concerns over privacy impacts. Request that proposed home be limited to no basement and a single story. (Staff note: the IR guidelines cannot limit homes to one-story with no basement. Basements, however, may be required to be adjusted to address tree protection issues and the height, mass, size and location of the second floor would be subject to the IR guidelines.) • 2343 Webster Street neighbor: Large “McMansion” style home undermining character of neighborhood that features historic Stedman homes. Second floor roof volume and excavation for basement impacts on Oak tree. Impacts on solar access and privacy to this owner’s side yard garden area that has southern exposure and used for outdoor dining. (Staff note: the IR guidelines do not evaluate solar access/shading but do evaluate a home’s size and mass relative to the neighborhood context and positioning relative to the daylight plane, particularly when next to small or one-story homes). • 2360 Webster Street neighbor: Loss of Stedman house by demolish and change in neighborhood character. Impact of large two-story home on traditional one-story neighborhood. Inadequate on-site parking. Oak tree threatened by project. • 2334 Webster Street neighbor: The large oak tree is monumental in size. The basement should be modified as needed to ensure that the oak tree is not damaged. Comments on the revised plans (filed on June 6, 2019) were provided by neighbors on the directly abutting lots to the left (north), right (south), and across the street. • 2360 Webster Street neighbor: Similar concerns as previously stated. Main comment is house is too massive. • 2397 Webster Street neighbor: Similar concerns as previously stated, but new comments acknowledge the positive esthetic improvements at front of house. Main comments relate to cedar tree not being shown, privacy (balcony and windows) plus not showing this neighbor’s pool, and house still massive and doesn’t belong on this street. • 2343 Webster Street neighbor: Similar concerns as previously stated, but new comments acknowledge some height and mass reduction. Still see house as a monster house larger than any other on the block and intrusive to the neighborhood context with unnecessary use of building volume along with privacy concerns with proposed second floor deck. At the time of this review no additional neighbor comments are available for this third plan set submittal. Summary of Design Changes Topic Initial Design Second Revised Design Front Setback 25’-6” (main wall at both floors) 21’-4” (26’-10” main wall) Daylight Plane Clearance 6” left side, 6” right side 2’-6” left side, 2’-6” right side Total Floor Area 3,133 SF (max. 3,134 SF) 2,935 SF Second Floor Area 1,464 SF (46.7%) 1,310 SF (44.6%) Height (high ridge) 29’-10” 26’-1.5” Height (second floor eave) 19’-0” 18’-0”; 15’-6” (left side/corner) Height (first floor eave) NA 9’-3” Plate Heights 9’-0” 1st floor, 8’-6” 2nd floor Upper floor lowered 1 to 4 feet Roof Pitch 8:12 6:12 Roof Overhang 1 foot 3 foot 1st Floor, 1 foot 2nd Floor Roof Form Hip with curved dormer at front Hip with lower bay windows Massing Boxy with small first floor projections Stepped with lower roof at stair Front Elevation Two-story wall face, entry form in front Roof across front at first floor Side Elevations Windows, deck railing No windows from 2nd floor Wall Material Stucco (smooth texture) Stucco (smooth texture) Roof Material Shingles Slate tile Window Material Not noted Metal (black) Garage/Entry Door Not noted Stained wood vertical board Window Detail deeply recessed windows deeply recessed windows Second Floor Balcony 27’ wide, 10’-4” deep (facing side) 12’ wide, 6’ deep (facing rear) Balcony Railing/Screen Glass to 3’-6” 5’-6” Stucco wall Added Landscape 2 trees front, 3 right side 1 front, 3 right side unspecified G1 — Site Planning: Placement of Driveway, Garage, and House Approval Criterion: The driveway, garage, and house shall be placed and configured to reinforce the neighborhood’s existing site patterns (i.e. Building footprint, configuration and location, setbacks, and yard areas) and the garage and driveway shall be subordinate to the house, landscaping and pedestrian entry as seen from the street. [Guideline Key Points: 1. Minimize the driveway’s presence and paving; 2. Locate the garage to be subordinate to the house; 3. Configure the house footprint to fit the neighborhood pattern; 4. Create landscaped open spaces between homes; 5. Locate the upper floor back from the front facade and/or away from side lot lines when next to one-story homes; and 6. Do not place the second floor so that it emphasizes the garage.] Comments: The proposal places the house closer to the front portion of the lot and generally breaks from neighborhood site planning patterns of sprawling home footprints with multiple yard orientations. Part of the siting and footprint configuration is based on providing distance from the existing rear yard oak tree to limit impacts on the oak tree from house and basement construction. The proposed house and basement sunken patio would set back 46’-8” from the rear lot line, which limits the portion of the house and sunken patio extending under the tree canopy to about 10 feet. A large setback from the tree is likely warranted for tree protection. The second floor is set back from the first floor at the front and in from the first floor at each side to use one story roof lines facing the street and adjacent one-story homes. This second-floor location responds to key point 5 of this guideline for conditions when adjacent to one-story homes. This is also a considerable change from the initial design that had a primary two-story building form with smaller flat roof attachments. The revised massing also results in clearance to the daylight plane on each side of the house considerably greater than the initial design and closer to the expectation shown on guideline illustration 1B. The garage is set back from the front of the house and narrow with a narrow driveway with minimal paving (pavers). This configuration is consistent with the site planning guideline. Existing landscape, including the street trees and large oak tree are retained. Four new trees or large shrubs are shown along the right, side lot line and one new tree is shown along the left side lot line next to the driveway. There would need to be two or three screening trees or a row of tall screening shrubs along the left side lot line between the rear corner of the house and the rear setback line. All landscape would need to be identified by botanical name and planting size. This could be addressed as approval conditions. Overall site planning with the second revised design responds to site and neighborhood conditions, considering protecting the large oak and adapting to the adjacent one-story homes. The site planning response would be sufficient to meet this guideline with the noted need for landscape conditions of approval. G2 — Neighborhood Compatibility for Height, Mass, and Scale Approval Criterion: The scale (perceived size), mass (bulk or volume) and height (vertical profile) of a new house or upper story addition shall be consistent with the existing neighborhood pattern with special attention to adapting to the height and massing of adjacent homes. [Guideline Key Points: 1. Do not overwhelm an adjacent one-story home; 2. Do not accentuate mass and scale with high first floor level relative to grade, tall wall planes, etc.; 3. Minimize height offsets to adjacent neighbors’ roof edges, including adjacent one-story roof edges; 4. Place floor area within roof forms to mitigate mass and scale; 5. Locate smaller forms forward of larger forms to manage perceived height; and 6. Use roof volume rather than wall plate height to achieve interior volume.] Comments: The height, mass, and scale of the proposed house has been reduced substantially from the initial proposal. See summary of changes above. As can be seen in the streetscape elevation the lowered eave and ridge heights, use of one-story forms and elongated roof edges and reductions to the upper floor size all contribute to the proposed home generally fitting with the existing context without a stark juxtaposition in height, mass, or scale to the adjacent homes. The first-floor eave is kept low, so its line adapts well to the adjacent homes. Roof offsets from the first to second floor are deep enough to be meaningful to mass reduction and the stair volume is closer to 1.5 stories tall than a full 2-stories tall, which with its radiused corner benefits the mass and scale relationship to the adjacent home. Overall, the height, mass, and scale of the proposal would be consistent with this guideline with reasonable adaptations provided to blend with the scale of adjacent homes. G3 — Resolution of Architectural Form, Massing, and Rooflines Approval Criterion: The architectural form and massing shall be carefully crafted to reduce visual mass and distinguish the house’s architectural lines or style. Roof profiles shall enhance the form, scale, and proportion of primary and secondary house volumes, while rendering garage and entry forms subordinate in mass and scale to principal building forms. Upper floor additions shall also be balanced and integrated with the existing building. [Guideline Key Points: 1. Adjust floor plans to work for building form; 2. Use the vocabulary of a particular style to compose forms and rooflines; 3. Avoid awkwardly placed additions; 4. Use a few well- proportioned masses to avoid a cluttered appearance of too many elements; and 5. Adjust roof layouts, ridge orientations, eave lines, etc. to reduce mass and enhance form.] Comments: The proposed forms are distinctive in character, including the general hip roof form and smaller secondary forms and radius corner treatment. The neighbor’s initial comment that the house would be a “McMansion” only seemed applicable to its relative size. With the revised design, the volume is significantly reduced, and the forms are more subdued with stepped hip roof lines and deep overhangs used to enhance the massing and scale. Plate heights are kept low at 7-‘6” or 7’-0” on the second floor with roof volume used for room height. Bay windows are used as secondary features and are well spaced. The general roof geometry is organized and not cluttered with unnecessary hips and valleys. Overall the massing would be well balanced while managing mass and bulk. Additionally, the garage would be a subordinate form as required and the entry would be blended into the main facade. The combined features of the design would meet this guideline. G4 — Visual Character of Street Facing Facades and Entries Approval Criterion: Publicly viewed facades shall be composed with a clear and cohesive architectural expression (i.e. The composition and articulation of walls, fenestration, and eave lines), and include visual focal point(s) and supportive use of materials and detailing. Entries shall be consistent with the existing neighborhood pattern and integrated with the home in composition, scale and design character. The carport or garage and garage door shall be consistent with the selected architectural style of the home. [Guideline Key Points: 1. Compose facades to have a unified/cohesive character; 2. Use stylistically consistent windows and proportion and adequate spacing between focal points; 3. Add visual character with architecturally distinctive eaves, window patterns and materials; 4. Do not use monumental entries/ relate entry type and scale to neighborhood patterns; and 5. Design garage openings and door panels to be modest in scale and architecturally consistent with the home.] Comments: Visible facades have an informal, asymmetrical composition but are organized. Hip roof forms with broad horizontal eaves are emphasized in the design. The main street facing windows are large squares divided into quarters. They are set in bays or stacked between floors or above the entry. The windows have deep, pocket style recesses from the wall face to create a shadow line and the black metal frames contrast with the stucco. The stained wood, vertical board garage and entry doors match in material and pattern and contrast well with the stucco. Slate tile roofing and smooth stucco wall surfaces fit the home’s style well and create a simple but balanced material palette. Overall the streetscape façade, material and detailing treatment would be consistent with this guideline. G5 — Placement of Second-Story Windows and Decks for Privacy Approval Criterion: The size, placement and orientation of second story windows and decks shall limit direct sight lines into windows and patios located at the rear and sides of adjacent properties in close proximity. [Guideline Key Points: 1. Gather information on neighbors’ privacy sensitive windows, patios, yards; 2. Mitigate privacy impacts with obscure glazing, high sill windows, permanent architectural screens or by relocating/reorienting windows; 3. Avoid windowless/unarticulated building walls, especially where visible from the street; and 4. Limit upper story deck size and locate decks to result in minimal loss of privacy to side or rear facing property.] Comments: Side facing windows on the second floor have been more or less eliminated from the design, even at the sides of window bays. There is one side facing window high above the stair landing near the front corner of the house that would have little or no privacy impact. At the rear deck, the deck size has been reduced and pulled away from the side lot line, and a 5’-6” stucco wall has been added to limit sideways views. This will significantly reduce impacts. There could be some impact from the deck over the left side lot line to the rear most window facing the side lot line on the 2343 Webster house. Evergreen screening trees or tall shrubs as noted under guideline one should be placed to improve privacy at the diagonal view angle. The impact is not a direct, close view, so landscape as a secondary measure would be suitable. Landscape is also proposed along the right, side lot line per sheet A1.0, but is not specified. This landscape would help screen sideways views from the deck to the 2397 Webster rear yard but needs to be specified on the plans. With the provision of added landscape screening noted here and under guideline one, and identification and approval of the proposed and additional landscape per approval conditions, this proposal would be consistent with the privacy requirements of this guideline. B. The following are recommended conditions for approval of this Individual Review application that shall be shown on building permit plans for approval: 1. On the site plan filed with the building permit show landscape (a row of tall shrubs and/or at least two trees) along the left side lot line starting from near the rear corner of the house and extending to the rear lot setback line. The trees and/or tall shrubs should be evergreen and form a relatively continuous screen with plants that can grow to at 20 feet tall under normal conditions. 2. All proposed trees and tall screening shrubs shown on the site plan shall be indicated with botanical names, and trees noted at a minimum 24-inch box size and shrubs a minimum 15- gallon size and noted to be installed prior to final building inspection at a minimum height of 8 feet. (Note: landscape information may be shown on a landscape plan separately from the site plan, but trees and tall shrubs should still be shown on the site plan graphically with a note referencing the landscape plan for additional information. Corporate Headquarters 1500 North Mantua Street P.O. Box 5193 Kent, OH 4240-5193 330-673-5685 Toll Free 1-800-828-8312 Fax: 330-673-0860 Western Region Office 6005 Capistrano Suite A Atascadero, CA 93422 Direct: 720-667-9236 barry.duncil@davey.com September 22nd, 2019 Gordana Pavlovic Gordana Design Studio, LLC 602 Hawthorne Ave. Palo Alto, CA 94301 650.483.4622 RE: Arborist Report and Tree Protection Plan for Potential Development Impacts at 2353 Webster St. in Palo Alto, California Dear Ms. Pavlovic, Thank you for contracting with Davey Resource Group regarding the above project. In support of your objectives, Davey Resource Group (DRG) is pleased to provide you with the attached report for the planned construction. A DRG International Society of Arboriculture (ISA) Certified Arborist conducted the site inspection of the trees that may be impacted by construction located at the above location in Palo Alto, California on February 3rd, as well as July 31st, 2019. The trees were assessed for location, size, current condition and overall health, as well as identifying critical and structural root zones to assist with tree protection plans. The attached report can be used to make informed decisions about demolition and construction planning, and long-term care of the trees. The survey determined the following: ▪ Twenty-one (21) trees within the potential impacts of the project scope were evaluated. ▪ Fourteen (14) species were identified with the most significant four (4) species listed as: valley oak (Quercus lobata), coast redwood (Sequoia sempervirens), ash (Fraxinus spp.) and southern magnolia (Magnolia grandiflora) ▪ Tree condition ratings ranged from 52% (Fair) to 75% (Good). ▪ It was determined that eighteen (18) trees will require some form of tree protection measures due to proposed site improvements. ▪ Two (2) trees are recommended for removal due to proposed site improvements. ▪ One (1) large valley oak will require extensive monitoring and specific procedures during demolition and construction Please feel free to contact me if you would like more information or have any questions. Sincerely, Emily Spillett Davey Resource Group Certified Arborist #WE-6702A 2353 Webster St., Palo Alto, CA 1 September 2019 ARBORIST REPORT AND TREE PROTECTION PLAN 2353 Webster St. Palo Alto, California August 2019 Revised September 2019 2353 Webster St., Palo Alto, CA 2 September 2019 Arborist Report & Tree Protection Plan for 2353 Webster St. Palo Alto, California Prepared for Gordana Pavlovic Gordana Design Studio, LLC 602 Hawthorne Ave. Palo Alto, CA 94301 August 2019 Revised September 2019 Prepared by Davey Resource Group A Division of The Davey Tree Expert Company 1500 North Mantua Street Kent, OH 44240 Contact: Ruth Williams Western Region Office 6005 Capistrano Suite A Atascadero, CA 93422 Phone: 503.880.3818 E-mail: ruth.williams@davey.com www.daveyresourcegroup.com Notice of Disclaimer Inventory data provided by Davey Resource Group is based on visual recording at the time of inspection. Visual records do not include testing or analysis and do not include aerial or subterranean inspection. Davey Resource Group is not responsible for discovery or identification of hidden or otherwise non-observable risks. Records may not remain accurate after inspection due to variable deterioration of inventoried material and site disturbance. Davey Resource Group provides no warranty with respect to the fitness of the urban forest for any use or purpose whatsoever or for future outcomes of the inventoried trees. 2353 Webster St., Palo Alto, CA 3 September 2019 Table of Contents Summary 4 Introduction 4 Background 4 Assignment 4 Limits of Assignment 5 Purpose and Use of Report 5 Observations 5 Methods 5 Site Observations 5 Tree Observations 5 Analysis and Discussion 5 Conclusion and Recommendations 6 Appendix A – Tree Photograph Summary 8 Appendix B – Tree Inventory and Condition Assessment 11 Appendix C - Tree Protection Plan Drawing 13 2353 Webster St., Palo Alto, CA 4 September 2019 Summary In August 2017, Davey Resource Group (DRG) was contracted by Gordana Pavlovic to explore the possibility of having a new home on the site, address concerns about the impacts the project might have on the trees in proximity and define an area on the lot where the new construction would be possible at 2353 Webster St. in Palo Alto, CA, and what the condition of the trees are in before any design or construction began. In February 2019, DRG was again contracted by Ms. Pavlovic with a revised design as requested by the Planning department, to update the tree assessment and develop a tree protection plan for the existing trees. The revised design shifted the proposed building further away from a large oak to further protect this tree during and after construction. In the meantime, Jason Shirar, Arborist from S.P. McClenahan Co has been retained by Gordana to care and maintain the trees on the property. An International Society of Arboriculture (ISA) Certified Arborist (#WE-9234A) from DRG conducted the evaluation of twenty-one (21) trees that may be impacted by development on February 3rd, 2018. After receiving comments from the City of Palo Alto, DRG sent another arborist to the site to collect additional information about the trees and neighboring trees. The initial assessment did not note a neighboring Deodar Cedar and as there was some concern expressed by comment from a neighbor, on September 22, 2019, the neighboring Deodar Cedar was added to the assessment. The trees were assessed by their location, size, current condition, and overall health. The current site survey was used to plot the critical root zones (CRZ) of the trees to help guide construction options to reduce potential impacts on the trees. Tree condition was primarily fair (6 trees), while fourteen (14) trees were in good condition. It was determined that two (2) of the trees are recommended for removal due to site improvements, and fifteen (15) trees are recommended for varying degrees of tree protection measures as described in this report as well as the Tree Protection Plan. Tree #5 is a large oak that will require monitoring, specific demolition practices, and fencing during and after demolition to best determine the retention potential of this tree. Typical tree protection fence will include Type I and Type II as found in the Palo Alto Tree Technical Manual. Introduction Background Yali Zhou is planning construction at 2353 Webster St. in Palo Alto, CA. In 2017, DRG was contracted to address concerns about the impacts the project might have on the trees in proximity to development and what the condition of the trees are in before any construction began. Gordana Pavlovic requested that DRG provide feedback regarding a proposed residential design at 2353 Webster St., and how that design may be changed or updated to reflect less impact to a large oak specimen. In 2019, Ms. Pavlovic had designed a new building plan in response to DRG’s recommendations to create a larger Tree Protection Zone for the specimen tree. In February 2019, DRG was again contracted to assess the existing trees and provide Tree Protection Plans for the new proposed residence at 2353 Webster. It was requested on behalf of the homeowners that DRG provide an arborist report on the health of the trees, and to identify what tree protection measures may be needed before final plans are submitted to Palo Alto for approval of the new project. Assignment DRG was contracted to conduct a site evaluation of twenty-one (21) existing trees within the limits of the project scope at 2353 Webster St. in Palo Alto, CA and recommend any necessary tree protection measures for the identified trees. The survey included a visual assessment of the trees’ condition, observations of the site conditions and estimating the current critical root zones to assist with upcoming construction planning. 2353 Webster St., Palo Alto, CA 5 September 2019 Limits of Assignment Many factors can limit specific and accurate data when performing evaluations of trees, their conditions, and potential for failure or response to site disturbances. No soil or tissue testing was performed. All observations were made from the ground and no soil excavation to expose roots was performed. The most recent development plans were available to assist in determining potential construction impacts, but these did not include detailed demolition plans. The determinations and recommendations presented here are based on current data and conditions that existed at the time of the evaluation and cannot be a predictor of the ultimate outcome for the evaluated trees in the future. Purpose and Use of Report The purpose of this report is to provide a summary of the evaluations of the trees located at 2353 Webster St., including an assessment of the current condition and health, as well as providing a tree protection plan for all evaluated trees that may be impacted by construction plans. The findings in this report can be used to make informed decisions on design planning and be used to guide long-term care of the trees. This report and detailed tree protection plan can also be submitted to Palo Alto for permitting purposes. Should the development plans be revised, this report and plan must also be revised to remain valid. Observations Methods Only a visual inspection was used to develop the findings, conclusions, and recommendations found in this report. Data collection included measuring the diameter of significant trees at approximately 54 inches above grade (DBH), height estimation, canopy radius estimation, a visual assessment of tree condition, structure, and health, and a photographic record. Numerical values were assigned to grade the attributes of the roots, trunk, branches, and foliage, including structure and health, and to obtain an overall condition rating. No physical inspection of the upper canopy, sounding, root crown excavation, resistance drilling, or other technologies were used in the evaluation of the trees. Site Observations The surveyed site is a residence on a relatively flat location in Palo Alto, CA. Most of the grounds are landscaped. Tree Observations Twenty-one (21) trees were evaluated as part of this report. Four (4) important species were identified: valley oak (Quercus lobata), coast redwood (Sequoia sempervirens), ash (Fraxinus spp.) and southern magnolia (Magnolia grandiflora). Visual assessments determined tree condition ratings ranged from 52-58% (Fair, 6 trees) to 75% (Good, 14 trees). Tree diameters ranged from 8 to 72 inches. Finally, tree heights were estimated to be approximately 14 to 60 feet. Tree photographs are available upon request and a complete Tree Inventory and Condition Assessment can be found in Appendix A. Analysis and Discussion The surveyed trees are of a mixed size (age) class. Seven (7) trees are on the property under construction, while ten (10) trees are on adjacent property and four (4) are street trees. Lower tree condition ratings were based on trunk structure or damage, visible decay, minor dieback, poor structure, or observed stress. Tree #5 is an older tree that be considered mature and is located very close to the existing house. It is likely that many of the tree roots grow along the house and at the base of the of the existing footers, and this should be noted for the demolition phase. 2353 Webster St., Palo Alto, CA 6 September 2019 The diameters of the surveyed trees were used to illustrate the potential critical root zone (CRZ) of each tree. The CRZ is the area of soil around a tree where the minimum amount of roots considered critical to the health of the tree are located. The CRZ was calculated by multiplying the DBH by 0.83 feet (10 inches). For instance, tree #1 has a DBH of 12 inches and a calculated CRZ of 10 feet (12 x 0.83). This distance may extend beyond the tree canopy dripline and is normally considered the tree protection zone (TPZ). Tree protection fencing is normally installed to protect the CRZ, but at a minimum should be installed at the dripline. Like the CRZ, the structural root zone (SRZ) was also calculated using a commonly accepted method established by Dr. Kim Coder in Construction Damage Assessments: Trees and Sites.1 In this method, the root plate size (i.e. pedestal roots, zone of rapid taper area, and roots under compression) and limit of disruption based upon tree DBH is considered as a minimum distance that any disruption should occur during construction. Significant risk of catastrophic tree failure exists if structural roots within this given radius are destroyed or severely damaged. The SRZ is the area minimal or no disturbance should occur without arborist supervision. Both the CRZ and SRZ for the surveyed trees are illustrated in Appendix C. Conclusion and Recommendations Tree #5 will require extensive planning, additional budget and thorough communication with supervising arborist and the contractor. As the structural root zone may be impacted during demolition, it is critical that all demolition techniques minimize impacts in this area. Currently, the CRZ for this tree is estimated at approximately 11,000 square feet. Based on the proposed demolition that will occur, we estimate that 1850 square feet (17% percent) of this CRZ will be removed. Minor impact to the remaining CRZ area is anticipated from proposed demolition, restoration and utility connections. It is recommended that existing structure demolition is completed by hand from within the building footprint. No Equipment outside the footprint and an arborist should approve the equipment inside the footprint. All demolition and restoration work within the CRZs of retained trees shall be completed by hand and under arborist supervision. Existing soil moisture should be mimicked throughout demolition and construction. Subsequent protection measures should be considered through all stages of demolition and construction. This may include: tree growth regulator (tree #5); root protection matting and 4-6” inches of mulch; installing trunk wrap; using hand tools and light machinery when working in the Tree Protection Zone; watering, wetting and covering roots that may be exposed to sunlight and dry conditions; potentially leaving some parts of the foundation and existing footings in place as to minimally disturb existing roots. Additionally, all fill soils around tree #5 shall mimic existing native soils and shall not be over-compacted, as determined by a soil specialist. To facilitate the demolition of the existing building foundation, the tree protection should be temporarily moved to the outside of the demolition area once the Arborist has arrived onsite to document any tree impacts. Root protection matting and mulch may be necessary to minimize soil compaction and impacts to the existing roots within the Tree Protection Zone, as determined by the supervising arborist. When demolition is complete, soil should be immediately backfilled and incorporated with the native soils using pneumatic air tools, and finally the area should be mulched. Then the tree protection fence should be replaced and remain throughout the duration of construction. All work performed in the TPZ of the trees to be retained should be supervised by a Certified Arborist. Temporary root protection is recommended by using a 4-6” layer of mulch. In addition, the proposed electric 1 Dr. Kim D. Coder, University of Georgia July 1996 2353 Webster St., Palo Alto, CA 7 September 2019 utility connection through the TPZ must be excavated by air tools or by hand, or be directional bored, to avoid unnecessary root damage. The utility work will require arborist oversight. Tree protection measures should be in place before any site work occurs, including: ● Installation of 6’ min high tree protection fencing ● Mulching according to the tree protection plans ● Posting signage on the tree protection fencing ● Pre-work meetings and site visits with the design team ● Ensuring that contractor and subcontractors know when arborist supervision is required This helps to ensure that everyone is on-board towards the same goal- retaining and preserving the twenty- one (21) trees while maintaining a safe residential setting. Following construction, the trees should be monitored monthly by a Certified Arborist to ensure the condition and structure of the tree do not decline over time or become hazardous. If a change in state is observed, the Arborist should recommend mitigation measures, which may include, but are not limited to, increased monitoring, pruning, general plant health care, or removal. 2353 Webster St., Palo Alto, CA 8 September 2019 Appendix A – Tree Photograph Summary Additional photos upon request Image 1. Trees #1-3 along Webster St. 2353 Webster St., Palo Alto, CA 9 September 2019 Image 2. Tree #5 behind house 2353 Webster St., Palo Alto, CA 10 September 2019 Image 3. Tree #5 2353 Webster St., Palo Alto, CA 11 September 2019 Image 4. Tree #5 2353 Webster St., Palo Alto, CA 12 September 2019 Appendix B – Tree Inventory and Condition Assessment Attached 2353 Webster St., Palo Alto, CA 13 September 2019 Appendix C - Tree Protection Plan Drawing Attached Wetland 5300 Wellington Branch Drive • Suite 100 Gainesville, Virginia 20155 Phone: 703-679-5600 • Fax: 703-679-5601 www.wetlandstudies.com Studies and Solutions, Inc.R Ci t y o f P a l o A l t o Tr e e P r o t e c t i o n - I t ’ s P a r t o f t h e P l a n ! Ma k e s u r e y o u r c r e w s a n d s u b s d o t h e j o b r i g h t ! Fe n c e d e n c l o s u r e s a r o u n d t r e e s a r e e s s e n t i a l t o p r o t e c t t h e m b y k e e p i n g t h e f o l i a g e c a n o p y a n d b r a n c h i n g s t r u c t u r e c l e a r f r o m c on t a c t b y e q u i p m e n t , m a t e r i a l s a n d a c t i v i t i e s , pr e s e r v i n g r o o t s a n d s o i l c o n d i t i o n s i n a n i n t a c t a n d n o n - c o m p a c t e d s t a t e , a n d i d e n t i f y i n g t h e T r e e P r o t e c t i o n Z o n e ( T P Z ) i n w h ic h n o s o i l d i s t u r b a n c e i s p e r m i t t e d a n d a c t i v i t i e s a r e r e s t r i c t e d , un l e s s o t h e r w i s e a p p r o v e d . An a p p o v e d t r e e p r o t e c t i o n r e p o r t m u s t b e a d d e d t o t h i s s h e e t w h e n p r o j e c t a c t i v i t y o c c u r s w i t h i n t h e T P Z o f a r e g u l a t e d t r e e . Fo r d e t a i l e d i n f o r m a t i o n o n P a l o A l t o ' s r e g u l a t e d t r e e s a n d p r o t e c t i o n d u r i n g d e v e l o p m e n t , r e v i e w t h e Ci t y T r e e T e c h n i c a l M a n u a l ( T T M ) f o u n d a t w w w . c i t y o f p a l o a l t o . o r g / t r e e s / . T- 1 Sp e c i a l T r e e P r o t e c t i o n I n s t r u c t i o n S h e e t Ci t y o f P a l o A l t o Al l o t h e r t r e e - r e l a t e d r e p o r t s s h a l l b e a d d e d t o t h e s p a c e p r o v i d e d o n t h i s s h e e t ( a d d i n g a s n e e d e d ) In c l u d e t h i s s h e e t ( s ) o n P r o j e c t S h e e t I n d e x o r L e g e n d P a g e . A c o p y o f T - 1 c a n b e d o w n l o a d e d a t w w w . c i t y o f p a l o a l t o . o r g / a r b / f o r m s ZHOU RESIDENCE 2353 WEBSTER ST PALO ALTO, CALIFORNIA WSSI PROJECT # DRGWEST234 T- 1   ST R E E T T R E E P R O T E C T I O N S P E C I F I C A T I O N S - S E C T I O N 3 1 - 31 - 1 Gen e r a l - T r e e p r o t e c t i o n h a s t h r e e p r i m a r y f u n c t i o n s , 1 ) t o k e e p t h e f o l i a g e c a n o p y a n d b r a n c h i n g s t r u c t u r e c l e a r fro m c o n t a c t b y e q u i p m e n t , m a t e r i a l s a n d a c t i v i t i e s ; 2 ) t o p r e s e r v e r o o t s a n d s o i l c o n d i t i o n s i n a n i n t a c t a n d no n - c o m p a c t e d s t a t e a n d 3 ) t o i d e n t i f y t h e T r e e P r o t e c t i o n Z o n e ( T P Z ) i n w h i c h n o s o i l d i s t u r b a n c e i s p e r m i t t e d a n d act i v i t i e s a r e r e s t r i c t e d , u n l e s s o t h e r w i s e a p p r o v e d . 31- 2 R e f e r e n c e D o c u m e n t s a. D e t a i l 5 0 5 - I l l u s t r a t i o n o f s i t u a t i o n s d e s c r i b e d b e l o w . b. T r e e T e c h n i c a l M a n u a l (w w w . c i t y o f p a l o a l t o . o r g / t r e e s / ) 1. Tre n c h i n g R e s t r i c t i o n Z o n e s ( S e c t i o n 2 . 2 0 ( C ) ) 2. Arb o r i s t R e p o r t i n g P r o t o c o l ( S e c t i o n 6 . 3 0 ) 3. Sit e P l a n R e q u i r e m e n t s ( S e c t i o n 6 . 3 5 ) 31- 3 M a t e r i a l s a. T h e T r e e P r o t e c t i o n Z o n e ( T P Z ) : A r e s t r i c t e d a r e a a r o u n d t h e b a s e o f t h e t r e e w i t h a r a d i u s o f 1 0 t i m e s the d i a m e t e r o f t h e t r e e ' s t r u n k o r t e n f e e t , w h i c h e v e r i s g r e a t e r , e n c l o s e d b y f e n c i n g . b. T y p e I T r e e P r o t e c t i o n : Th e f e n c e s h a l l e n c l o s e t h e e n t i r e a r e a u n d e r t h e c a n o p y d r i p l i n e o r T P Z (w h i c h e v e r i s g r e a t e r ) o f t h e t r e e ( s ) t o b e p r o t e c t e d t h r o u g h o u t t h e l i f e o f t h e c o n s t r u c t i o n p r o j e c t . I n s o m e pa r k i n g a r e a s , i f f e n c i n g i s l o c a t e d o n p a v i n g o r c o n c r e t e t h a t w i l l n o t b e d e m o l i s h e d , t h e n t h e p o s t s m a y be s u p p o r t e d b y a n a p p r o p r i a t e g r a d e l e v e l c o n c r e t e b a s e , i f a p p r o v e d . c. T y p e I I T r e e P r o t e c t i o n : Fo r t r e e s s i t u a t e d w i t h i n a p l a n t i n g s t r i p , o n l y t h e p l a n t i n g s t r i p a n d y a r d s i d e of t h e T P Z s h a l l b e e n c l o s e d w i t h t h e r e q u i r e d c h a i n l i n k p r o t e c t i v e f e n c i n g i n o r d e r t o k e e p t h e s i d e w a l k an d s t r e e t o p e n f o r p u b l i c u s e . d. T y p e I I I T r e e P r o t e c t i o n : Tr e e s s i t u a t e d i n a t r e e w e l l o r s i d e w a l k p l a n t e r p i t , s h a l l b e w r a p p e d w i t h 2-i n c h e s o f o r a n g e p l a s t i c f e n c i n g f r o m t h e g r o u n d t o t h e f i r s t b r a n c h a n d o v e r l a i d w i t h 2 - i n c h t h i c k woo d e n s l a t s b o u n d s e c u r e l y ( s l a t s s h a l l n o t b e a l l o w e d t o d i g i n t o t h e b a r k ) . D u r i n g i n s t a l l a t i o n o f t h e pla s t i c f e n c i n g , c a u t i o n s h a l l b e u s e d t o a v o i d d a m a g i n g a n y b r a n c h e s . M a j o r s c a f f o l d l i m b s m a y a l s o req u i r e p l a s t i c f e n c i n g a s d i r e c t e d b y t h e C i t y A r b o r i s t . e. S i z e , t y p e a n d a r e a t o b e f e n c e d : All t r e e s t o b e p r e s e r v e d s h a l l b e p r o t e c t e d w i t h s i x ( 6 ' ) f o o t h i g h c h a i n lin k f e n c e s . F e n c e s a r e t o b e m o u n t e d o n t w o - i n c h d i a m e t e r g a l v a n i z e d i r o n p o s t s , d r i v e n i n t o t h e g r o u n d to a d e p t h o f a t l e a s t 2 - f e e t a t n o m o r e t h a n 1 0 - f o o t s p a c i n g . f. ' W a r n i n g ' s i g n s : A w a r n i n g s i g n s h a l l b e p r o m i n e n t l y d i s p l a y e d o n e a c h f e n c e a t 2 0 - f o o t i n t e r v a l s . T h e sig n s h a l l b e m i n i m u m 8 . 5 - i n c h e s x 1 1 - i n c h e s a n d c l e a r l y s t a t e : “ W A R N I N G - T r e e P r o t e c t i o n Zon e - T h i s f e n c e s h a l l n o t b e r e m o v e d a n d i s s u b j e c t t o a f i n e a c c o r d i n g t o P A M C S e c t i o n 8 . 1 0 . 1 1 0 . ” 31- 4 E x e c u t i o n a. D u r a t i o n : Tre e f e n c i n g s h a l l b e e r e c t e d b e f o r e d e m o l i t i o n , g r a d i n g o r c o n s t r u c t i o n b e g i n s a n d r e m a i n i n pla c e u n t i l f i n a l i n s p e c t i o n o f t h e p r o j e c t , e x c e p t f o r w o r k s p e c i f i c a l l y a l l o w e d i n t h e T P Z . W o r k o r s o i l dis t u r b a n c e i n t h e T P Z r e q u i r e s a p p r o v a l b y t h e p r o j e c t a r b o r i s t o r C i t y A r b o r i s t ( i n t h e c a s e o f w o r k aro u n d S t r e e t T r e e s ) . E x c a v a t i o n s w i t h i n t h e p u b l i c R O W r e q u i r e a S t r e e t W o r k P e r m i t f r o m P u b l i c Wor k s . b. D u r i n g c o n s t r u c t i o n 1. All n e i g h b o r s ' t r e e s t h a t o v e r h a n g t h e p r o j e c t s i t e s h a l l b e p r o t e c t e d f r o m i m p a c t o f a n y k i n d . 2. Th e a p p l i c a n t s h a l l b e r e s p o n s i b l e f o r t h e r e p a i r o r r e p l a c e m e n t p l u s p e n a l t y o f a n y p u b l i c l y o w n e d tre e s t h a t a r e d a m a g e d d u r i n g t h e c o u r s e o f c o n s t r u c t i o n , p u r s u a n t t o S e c t i o n 8 . 0 4 . 0 7 0 o f t h e P a l o Alto M u n i c i p a l C o d e . 3. Th e f o l l o w i n g t r e e p r e s e r v a t i o n m e a s u r e s a p p l y t o a l l t r e e s t o b e r e t a i n e d : a. No s t o r a g e o f m a t e r i a l , t o p s o i l , v e h i c l e s o r e q u i p m e n t s h a l l b e p e r m i t t e d w i t h i n t h e T P Z . b. The g r o u n d u n d e r a n d a r o u n d t h e t r e e c a n o p y a r e a s h a l l n o t b e a l t e r e d . c. Tre e s t o b e r e t a i n e d s h a l l b e i r r i g a t e d , a e r a t e d a n d m a i n t a i n e d a s n e c e s s a r y t o e n s u r e s u r v i v a l . EN D O F S E C T I O N Wetland 5300 Wellington Branch Drive • Suite 100 Gainesville, Virginia 20155 Phone: 703-679-5600 • Fax: 703-679-5601 www.wetlandstudies.com Studies and Solutions, Inc.R Ci t y o f P a l o A l t o Tr e e P r o t e c t i o n - I t ’ s P a r t o f t h e P l a n ! Ma k e s u r e y o u r c r e w s a n d s u b s d o t h e j o b r i g h t ! T- 2 Sp e c i a l T r e e P r o t e c t i o n I n s t r u c t i o n S h e e t Ci t y o f P a l o A l t o Al l o t h e r t r e e - r e l a t e d r e p o r t s s h a l l b e a d d e d t o t h e s p a c e p r o v i d e d o n t h i s s h e e t ( a d d i n g a s n e e d e d ) In c l u d e t h i s s h e e t ( s ) o n P r o j e c t S h e e t I n d e x o r L e g e n d P a g e . A c o p y o f T - 1 c a n b e d o w n l o a d e d a t w w w . c i t y o f p a l o a l t o . o r g / a r b / f o r m s ZHOU RESIDENCE 2353 WEBSTER ST PALO ALTO, CALIFORNIA WSSI PROJECT # DRGWEST234 T- 2   Wetland 5300 Wellington Branch Drive • Suite 100 Gainesville, Virginia 20155 Phone: 703-679-5600 • Fax: 703-679-5601 www.wetlandstudies.com Studies and Solutions, Inc.R T- 3 Sp e c i a l T r e e P r o t e c t i o n I n s t r u c t i o n S h e e t Ci t y o f P a l o A l t o Al l o t h e r t r e e - r e l a t e d r e p o r t s s h a l l b e a d d e d t o t h e s p a c e p r o v i d e d o n t h i s s h e e t ( a d d i n g a s n e e d e d ) In c l u d e t h i s s h e e t ( s ) o n P r o j e c t S h e e t I n d e x o r L e g e n d P a g e . A c o p y o f T - 1 c a n b e d o w n l o a d e d a t w w w . c i t y o f p a l o a l t o . o r g / a r b / f o r m s ZHOU RESIDENCE 2353 WEBSTER ST PALO ALTO, CALIFORNIA WSSI PROJECT # DRGWEST234 T- 3   Wetland 5300 Wellington Branch Drive • Suite 100 Gainesville, Virginia 20155 Phone: 703-679-5600 • Fax: 703-679-5601 www.wetlandstudies.com Studies and Solutions, Inc.R T- 4 Sp e c i a l T r e e P r o t e c t i o n I n s t r u c t i o n S h e e t Ci t y o f P a l o A l t o Al l o t h e r t r e e - r e l a t e d r e p o r t s s h a l l b e a d d e d t o t h e s p a c e p r o v i d e d o n t h i s s h e e t ( a d d i n g a s n e e d e d ) In c l u d e t h i s s h e e t ( s ) o n P r o j e c t S h e e t I n d e x o r L e g e n d P a g e . A c o p y o f T - 1 c a n b e d o w n l o a d e d a t w w w . c i t y o f p a l o a l t o . o r g / a r b / f o r m s ZHOU RESIDENCE 2353 WEBSTER ST PALO ALTO, CALIFORNIA WSSI PROJECT # DRGWEST234 T- 4   Attachment H Project Plans Hardcopies of project plans are provided to the Chief Planning Official. These plans are available to the public online and/or by visiting the Planning and Community Environmental Department on the 5th floor of City Hall at 250 Hamilton Avenue. Directions to review Project plans online: 1. Go to: https://paloalto.buildingeye.com/planning 2. Search for “2353 Webster Street” and open record by clicking on the green dot 3. Review the record details on the left side and open the “more details” option 4. Use the “Records Info” drop down menu and select “Attachments” 5. Open the attachment named “2353 Webster Approved Plans” and dated 12/05/19 to review the tentatively approved plan set.