TO: HONORABLE MAYOR FROM: Kerrie Romanow
AND CITY COUNCIL
SUBJECT: SEE BELOW DATE: October 24, 2022
Approved Date
11/4/22
COUNCIL DISTRICT: 4
SUBJECT: SAN JOSE MUNICIPAL WATER SYSTEM’S WATER SUPPLY
ASSESSMENT FOR THE SEELY AVENUE MIXED USE PROJECT
RECOMMENDATION
Approve San José Municipal Water System’s Water Supply Assessment for the Seely Avenue Mixed Use Project.
OUTCOME
City Council approval of the Water Supply Assessment (WSA) will fulfill the requirements of the California Water Code and the California Environmental Quality Act.
BACKGROUND
A WSA has been prepared for the proposed Seely Avenue Mixed Use Project (Project) as required by State law. The Project site is located at the intersection of Montague Expressway and Seely Avenue in the San José Municipal Water System’s (Muni Water) North San José/Alviso service area. The Project will include the development of approximately 1,480 residential units and 54,000 square feet of retail space.
California Water Code Section 10910 (Senate Bill 610) requires that the water retailer prepare a water supply assessment for certain types of proposed projects, including one that would demand an amount of water equal to or greater than that required by a 500-dwelling unit project. The Project meets the criteria for preparing a WSA, as it will include the construction of more than 500 dwelling units.
The purpose of a WSA is to analyze and document sources of water supply, quantify water demands, evaluate drought impacts, and provide a comparison of water supply and demand so that a determination of water supply sufficiency can be made for large development projects in connection with the City’s consideration of whether to approve the project.
COUNCIL AGENDA: 11/15/22
FILE:
ITEM:
22-1652
2.10 HONORABLE MAYOR AND CITY COUNCIL
October 24, 2022
Subject: Seely Avenue Mixed Use Project Water Supply Assessment
Per Section 15155(b) of the CEQA Guidelines and Section 10910(g) of the California Water Code, the governing body of a public water system that will serve a “water demand project” must approve a water supply assessment at a regular or special meeting. In its role as the governing body for Muni Water, City Council is the appropriate decision-making body for approving the WSA prepared for the project.
ANALYSIS
The WSA (see Attachment) assesses whether Muni Water’s existing and future water supplies for the North San José/Alviso service area would be adequate to meet the Project’s projected water demands. Although Muni Water does not currently provide water to the project site, it is the water retailer for the area and will be supplying both potable and recycled water to the Project in the future.
The WSA projects the Project’s maximum water demands at approximately 607 acre-feet per year, which is equivalent to approximately 0.54 million gallons per day. Of this total, 13 acre- feet per year is projected to be supplied from recycled water and 594 acre-feet per year is projected to be supplied by potable water. A majority of the potable water demand is associated with residential use.
As discussed in the WSA, potable water is provided to Muni Water’s North San José service area from the San Francisco Public Utilities Commission. In 2009, Muni Water entered into both a master Water Supply Agreement (the agreement common to all Bay Area Water Supply and Conservation Agency agencies), and a Water Sales Contract (specific to Muni Water) with the San Francisco Public Utilities Commission. The City currently has a contract for up to 5,041 acre-feet per year (4.5 million gallons per day); this contract is both temporary and interruptible.
The Water Supply Agreement with the San Francisco Public Utilities Commission was amended and restated in 2018 and will remain in place until June 30, 2034. In addition, a 2021 Amended and Restated Water Supply Agreement is being circulated among the parties for signature.
However, that amendment does not substantively alter the City’s rights as described in the WSA.
Muni Water also owns and operates four groundwater wells in the Project’s service area. Two of the wells are currently permitted to be used under normal conditions to supply water, and the other two are available for emergency use purposes. A condition of project approval by the City will be the construction of a domestic water supply well at the project site to meet the demands of the Project, which is necessary to ensure continued availability of potable water to the Project.
CONCLUSION
The WSA identifies the water supply sources available to meet the Project’s potable and recycled demands, and approval of the document will meet CEQA requirements identified within the California Water Code.
HONORABLE MAYOR AND CITY COUNCIL
October 24, 2022
Subject: Seely Avenue Mixed Use Project Water Supply Assessment
EVALUATION AND FOLLOW-UP
No additional follow-up action with City Council is expected at this time.
CLIMATE SMART SAN JOSE
The recommendation in this memorandum has no effect on Climate Smart San José energy, water, or mobility goals.
PUBLIC OUTREACH
This memorandum will be posted on the City Council’s Agenda website for the November 15, 2022 meeting.
COORDINATION
This memorandum was coordinated with the City Attorney’s Office, the City Manager’s Budget Office, and the Department of Planning, Building, and Code Enforcement.
COMMISSION RECOMMENDATION/INPUT
No commission recommendation or input is associated with this action.
CEQA
Statutorily Exempt, File No. PP17-001, Feasibility and Planning Studies; CEQA Guidelines Section 15262.
/s/
KERRIE ROMANOW
Director
For questions, please contact Jeff Provenzano, Deputy Director at (408) 277-3671.
Attachment: Draft Water Supply Assessment: Seely Avenue Mixed Use Project
DRAFT WATER SUPPLY ASSESSMENT
Seely Avenue Mixed Use Project
SEPTEMBER 2022
PREPARED FOR
DUFFY AND ASSOCIATES
PREPARED BY
LUHDORFF AND SCALMANINI
CONSULTING ENGINEERS
ATTACHMENT
Water Supply Assessment – Seely Avenue Mixed Use Project
Duffy and Associates I August 2022
TABLE OF CONTENTS
1SECTION 1. INTRODUCTION .......................................................................................................... 1
1.1. Project Description ............................................................................................................................. 1
1.2. Purpose of Water Supply Assessment ............................................................................................ 2
1.3. Preparation of Water Supply Assessment ...................................................................................... 2
1.4. Public Water System Serving the Project ........................................................................................ 2 2SECTION 2. WATER DEMANDS ...................................................................................................... 3 3SECTION 3. CURRENT AND FUTURE WATER SUPPLY .................................................................... 4
3.1. Sources of Supply .............................................................................................................................. 4
3.2. Imported and Purchased Water ....................................................................................................... 5
3.3. Local Groundwater ............................................................................................................................ 6
3.4. Recycled Water .................................................................................................................................. 9 4SECTION 4. EXISTING WATER DEMANDS .................................................................................... 10
4.1. Current & Future Demands ............................................................................................................ 10
4.2. Single Dry Year Supplies and Demands ......................................................................................... 11
4.3. Multiple Dry Years Supply and Demand ........................................................................................ 12 5SECTION 5. SUPPLY SUFFICIENCY ANALYSIS ................................................................................ 13
Water Supply Assessment – Seely Avenue Mixed Use Project
Duffy and Associates II August 2022
LIST OF TABLES
Table 1. Potable Commercial Water Use Coefficients .................................................................... 4 Table 2. Project Water Demands .................................................................................................... 4 Table 3. Water Source by SJMWS Service Area .............................................................................. 4 Table 4. Santa Clara Plain Principal Aquifer Water Budget (2010‐2019) ....................................... 8 Table 5. Demands for Potable and Non‐Potable Water ‐ Actual .................................................. 10 Table 6. SJMWS Projected Potable and Non‐Potable Water Demand ......................................... 10 Table 7. Single Dry Year Supply and Demand Comparison (Potable) (AFY) ................................. 12 Table 8. Multiple Dry Year Supply and Demand Comparison (Potable) (AFY) ............................. 13 Table 9. Projected SJMWS Potable Demand and Supply with Project Demand and Supply (AFY) .............................................................................................................................................. 14 Table 10. Normal, Single, and Multiple Dry Year Potable Water Supply and Demand Projections (AFY) ..................................................................................................................................... 15 Table 11. Normal Year Supply and Demand Comparison (Recycled) (AFY) ................................. 15
LIST OF FIGURES
Figure 1. Project Location Map ....................................................................................................... 1 Figure 2. SJMWS Service Areas ....................................................................................................... 2 Figure 3. Santa Clara Plain (San José) Index Well 07S01W25L001 Hydrograph. ............................ 7 Figure 4. SJMWS Well Locations ..................................................................................................... 8 Figure 5. Projected SJMWS Water Demand ................................................................................. 11 Figure 6. Projected SJMWS and Project Potable Water Supply and Demand .............................. 14
APPENDICES
Appendix A.References ....................................................................................................................... 16
Water Supply Assessment – Seely Avenue Mixed Use Project
Duffy and Associates III August 2022
LIST OF ACRONYMS AND ABBREVIATIONS
Acronym Meaning
AFY Acre‐feet/year
CEQA California Environmental Quality Act
City City of San José
CVP Central Valley Project
DDW California Water Resources Control Board, Department of Drinking Water DWR California Department of Water Resources
GPD GPM Gallons per day Gallons per minute
IP Industrial Park
MGD Million gallons per day
NSJ/Alviso North San José/Alviso
Project Seely Avenue Mixed Use Project
RWF San José/Santa Regional Wastewater Facility
SBWR SF South Bay Water Recycling Square Foot
SFPUC San Francisco Public Utilities Commission
SJMWS San José Municipal Water System
SWP State Water Project
UWMP Urban Water Management Plan
Valley Water Santa Clara Valley Water District WSA
Water Supply Assessment WSAP Water Shortage Allocation Plan
Water Supply Assessment – Seely Avenue Mixed Use Project
Duffy and Associates 1 August 2022
1 SECTION 1. INTRODUCTION
1.1. Project Description
The proposed 22‐acre, Seely Avenue Mixed Use Project (Project) site is located north of Montague Expressway and east of Seely Avenue in the City San José (Figure 1). The project will be constructed on two parcels (APN No. 097‐15‐034 and 097‐15‐033) that are approximately 11 acres each. Both parcels are currently zoned as Industrial Park (IP).
Figure 1. Project Location Map
The Project will include the development of approximately 1,480 residential units, consisting of three market rate apartment buildings, one affordable apartment building, and a for‐sale townhome community. There will also be approximately 54,000 square feet of retail space, including a 42,000 square feet anchor space aimed to accommodate a grocery tenant. The project will also feature an approximately 2.50‐acre public park. The project will also include the installation of a domestic water supply well to support the potable water demand of the Project.
Water Supply Assessment – Seely Avenue Mixed Use Project
Duffy and Associates 2 August 2022
1.2. Purpose of Water Supply Assessment
The purpose of a Water Supply Assessment (WSA) is to assess whether the total projected water supplies available for a project during normal; single dry; and multiple dry water years during a 20‐year projection and will meet the projected water demand associated with the proposed project.
Under Senate Bill 610 (2001), a WSA is required for any “project” that meets the criteria of Water Code Sections 10910 and 10912. A WSA is required for the 618 E. Trimble Project because it is subject to the California Environmental Quality Act (CEQA) and will include the development of more than 500 dwelling units.
1.3. Preparation of Water Supply Assessment
This WSA was prepared using information developed for and contained in the City of San José, 2020 Urban Water Management Plan (UWMP) and project planning and design documents supplied to LSCE by the Project applicant. The information, values, and projections contained herein are consistent the City of San José 2020 UWMP.
1.4. Public Water System Serving the Project
The Project will be served by the San José Municipal Water System (SJMWS). The SJMWS provides potable and non‐potable water to four service areas: (1) North San José/Alviso (NSJ/Alviso), (2) Evergreen, (3) Coyote Valley, and (4) Edenvale (Figure 2).
Figure 2. SJMWS Service Areas
Water Supply Assessment – Seely Avenue Mixed Use Project
Duffy and Associates 3 August 2022
The Project is located in SJMWS’s (1) NSJ/Alviso service area (Figure 2). The NSJ/Alviso service area consists of 5,600 acres and extends from Trimble Road on the south to the Alviso Slough on the north. The area is bordered on the west by the Guadalupe River and on the east by Coyote Creek.
Land use in the NSJ/Alviso service area is predominantly industrial, with some residential and commercial properties.
Potable and non‐potable water is supplied to the SJMWS by the following:
San Francisco Public Utilities Commission (SFPUC) – The SJMWS purchases potable water from the SFPUC. This supply is predominately from the Hetch Hetchy reservoir, with additional local surface water.
Valley Water – The SJMWS purchases treated surface water from Valley Water (previously called the Santa Clara Valley Water District) under a treated water contract.
This supply include water from the Sacramento‐San Joaquin Delta, and local surface water.
Groundwater – The SJMWS owns and operates four domestic supply wells in the NSJ/Alviso service area. Two of the wells are permitted by California Water Resources Control Board, Department of Drinking Water (DDW) for normal use. Two of the wells are permitted by DDW for emergency use only.
Recycled Water ‐ The City of San José operates the South Bay Water Recycling (SBWR) system and distributes recycled water generated by the San José/Santa Clara Regional Wastewater Facility. The recycled water is used for non‐potable purposes such as agriculture; industrial cooling and processing; and irrigation of golf courses, parks, and schools.
Potable and non‐potable water demand for the NSJ/Alviso service area is met with purchased water from the City and County of San Francisco’s Regional Water System (RWS), which is operated by the SFPUC, groundwater from the Santa Clara Subbasin‐ Santa Clara Plain, and recycled water from the South Bay Water Recycling (SBWR) Program.
Potable water purchased from Valley Water is not available in the NSJ/Alviso service area and is not considered a source of potable water for the purposes of this WSA. 2 SECTION 2. WATER DEMANDS
The Project includes approximately 1,500 dwellings and 54,000 square feet of retail space. Project residential potable water demand was calculated by multiplying the number of dwellings by the average daily dwelling water usage. Project retail potable water demands were calculated by multiplying the square footage of the planned market and small structure retail space by potable commercial water use coefficients (Table 1).
Water Supply Assessment – Seely Avenue Mixed Use Project
Duffy and Associates 4 August 2022
Table 1. Potable Commercial Water Use Coefficients
Use Coefficients (gpd/sf)
Retail 0.240
Market 0.900
Retail (Small Structure) 0.076
Calculated daily potable water demands for residential and retail use were multiplied by 3.8 and
2.4, respectively, to calculate peak hour demand. Based on the peak hour demand volume, residential potable water demand was 565 AFY (acre‐feet/year) and retail demand was 29 AFY for a total project potable water demand of 594 AFY. Project outdoor water use (residential and retail) is projected to be 13 AFY and will be met by utilizing recycled water. Project water demands are summarized in Table 2.
Table 2. Project Water Demands
Use Type AFY
Residential Potable 565
Commercial Potable 29
Outside Recycled 13
Total 607
3 SECTION 3. CURRENT AND FUTURE WATER SUPPLY
3.1. Sources of Supply
SJMWS relies on four sources of supply: surface water from SFPUC, local and imported surface water from Valley Water, groundwater from the Santa Clara groundwater basin, and recycled water from the SBWR Program. As mentioned above in Section 1.4, the City has four separate service areas, and each service area has its own unique water sources. Table 3 provides a summary of the water source(s) for each service area.
Table 3. Water Source by SJMWS Service Area
Service Area SFPUC Valley Water Groundwater Recycled Water North San José/Alviso X X X
Evergreen X X X
Edenvale X X
Coyote Valley X X
Water Supply Assessment – Seely Avenue Mixed Use Project
Duffy and Associates 5 August 2022
The water sources utilized by SJMWS (discussed below) are generally considered to be consistent sources, except during times of drought during which supplies would be decreased based on reduced availability of wholesale supplies, as discussed in this section. This section includes the amount of supply from each source that was purchased historically and is anticipated to be purchased in the future to supply the project’s service area as determined by SJMWS.
3.2. Imported and Purchased Water
SFPUC – Wholesaler
The NSJ/Alviso service area receives water from the RWS, which is operated by the SFPUC. This supply is predominantly from the Sierra Nevada Mountain range delivered through the Hetch Hetchy aqueducts, but also includes treated water produced by the SFPUC from its local watersheds and facilities in Alameda and San Mateo counties. There are two turnout connections from SFPUC’s Bay Division Pipelines No. 3 and No. 4 to the NSJ/Alviso service area.
The amount of imported water available to SFPUC’s customers is constrained by hydrology, physical facilities, and the institutional parameters that allocate the water supply of the Tuolumne River. Due to these constraints, SFPUC is very dependent on reservoir storage to firm‐ up its water supplies. The SFPUC serves its retail and wholesale water demands with an integrated operation of local Bay Area water production and imported water from Hetch Hetchy.
The business relationship between the SFPUC and its wholesale customers is largely defined by the Water Supply Agreement (WSA) between the City and County of San Francisco and Wholesale Customers in Alameda, San Mateo, and Santa Clara Counties. The WSA was entered into in July 2009 and was amended and restated in 2018. In addition, a 2021 Amended and Restated Water Supply Agreement is being circulated among the parties for signature. However, that amendment does not substantively alter the City’s rights as described in the WSA. This 25‐year WSA replaced the 1984 Settlement Agreement and Master Water Sales Contract and will expire on June 30, 2034, unless extended by two additional five‐year option terms. The WSA addresses the rate‐making methodology used by the SFPUC in setting wholesale water rates for its customers in addition to addressing water supply and water shortages for the RWS. The WSA serves as the master agreement, and it provides a 184 million gallons per day (MGD) Supply Assurance to all the permanent SFPUC wholesale customers on an annual average basis. Under the WSA, the City of San José has a temporary uninterruptable supply. However, The SFPUC must provide 10 years notice to interrupt the supply and seek out additional sources of water.
The WSA is supplemented by an individual Water Sales Contract between SFPUC and each individual retailer, also entered into in July 2009. The individual Water Sales Contract indicates any specific conditions between SFPUC and the retailer. The contract currently held by the City of San José with SFPUC was most recently renewed in 2009 and continues to be a temporary and interruptible supply contract. The City of San José has no Individual Supply Guarantee but does have an Interim Supply Allocation of 4.5 MGD (5,041 AFY).
Water Supply Assessment – Seely Avenue Mixed Use Project
Duffy and Associates 6 August 2022
The Water Supply Agreement between SFPUC and its wholesale customers contains a Water Shortage Allocation Plan (WSAP), which describes the method for allocating water during supply shortages. The Tier 1 Plan allocates water from the RWS between San Francisco retail and wholesale customers during system‐wide shortages of 20% or less. The Tier 1 Plan was amended in the 2018 WSA to ensure that retail customers also conserved during drought conditions. The Tier 2 Plan allocates the collective wholesale customer share among the wholesale customers.
Valley Water – Wholesaler
SJMWS purchases treated surface water from Valley Water under a treated water contract. Valley Water contracts with the US Bureau of Reclamation and the State to receive imported Central Valley Project (CVP) water and State Water Project (SWP) water. Valley Water also operates its conjunctive use system of surface water from local watersheds and groundwater. Valley Water’s water supply system is comprised of local reservoirs, the groundwater subbasins, groundwater recharge facilities, treatment plants, a treated water transmission system, imported supplies, and raw water conveyance facilities. Valley Water supplies water to local retail water agencies which in turn provide it to their retail customers in Santa Clara County. Valley Water has an active conjunctive use water management program to optimize the use of groundwater and surface water, and to prevent groundwater overdraft and land subsidence. Both groundwater and imported water are sold to retailers. While SJMWS purchases treated water supplies from Valley Water, this particular water supply source is not available or used in the project’s service area.
3.3. Local Groundwater
The Santa Clara Subbasin‐Santa Clara Plain is located in a structural trough that is bounded by the Santa Cruz Mountains to the west and the Diablo Range to the east. The subbasin, which is approximately 22 miles long, narrows from a width of 15 miles near the County’s northern boundary to about half a mile wide at the Coyote Narrows. The plain underlies the northerly portion of the Santa Clara County and includes the majority of the streams and recharge facilities operated by Valley Water. The plain has a surface area of 225 square miles and is approximately 15 square miles smaller than the Santa Clara Subbasin, since it does not include the Coyote Valley portion of the Santa Clara Subbasin. Although hydraulically connected, Valley Water refers to the Coyote Valley separately since it is in a different groundwater charge zone than the Santa Clara Plain and has fewer water supply options than the Santa Clara Plain.
The groundwater basin in Santa Clara County is not adjudicated and has not been identified or projected to be in overdraft by the California Department of Water Resources (DWR). The quality, supply, and management of the local groundwater basin is monitored and managed by Valley Water who acts as the Groundwater Sustainability Agency for Santa Clara. In 2016, Valley Water completed and submitted an Alternative plan to DWR in lieu of a Groundwater Sustainability Plan to meet the requirements of the Sustainable Groundwater Management Act of 2014. The Alternative Plan was approved by DWR in 2017.
Water Supply Assessment – Seely Avenue Mixed Use Project
Duffy and Associates 7 August 2022
Groundwater in the subbasin is managed by Valley Water using in‐lieu recharge programs that maintain adequate storage to meet annual water supply needs and provide a buffer against drought or other shortages. According to Valley Water’s Annual Groundwater Report for Calendar Year 2019, groundwater levels in the subbasin fully recovered from the 2012‐2016 drought.
Figure 3. Santa Clara Plain (San José) Index Well 07S01W25L001 Hydrograph.
The estimated groundwater storage in the subbasin at the end of 2019 was 315,700 AF, which represents an increase in storage of 6,300 AF over 2018. Total groundwater use in the subbasin in 2019 was 57,700 AF which was 9% less than the previous year and well below the long‐term average use of 95,000 AF due primarily to the increased use of treated surface water.
A water budget for the Santa Clara Plain for calendar years 2010 through 2019 is shown in Table 4. The water budget is based on Valley Water’s groundwater flow model for the Santa Clara Plain and represents inflows and outflows for the principal aquifer. Although the water budget can vary significantly from year to year, on average, there was an average annual increase in storage by about 3,000 AFY for the Santa Clara Plain over this 10‐year period.
Water Supply Assessment – Seely Avenue Mixed Use Project
Duffy and Associates 8 August 2022
Table 4. Santa Clara Plain Principal Aquifer Water Budget (2010‐2019)
Water Budget Component AFY
Inflow
Managed Recharge 53,000
Natural Recharge 25,500
Subsurface Inflow 7,500
Total Inflow 86,000
Outflow
Groundwater Pumping 75,500
Subsurface Outflow 7,500
Total Outflow 83,000
Change in Storage 3,000
Valley Water expects groundwater demand to increase in the Llagas and Santa Clara subbasins from 306,000 AFY in 2020 to approximately 345,000 AFY in 2045 (2020 UWMP). Although projected 2045 demand is higher than present demand, this number is still down from a peak in the 1990s and 2000s because of significant conservation efforts from Valley Water and the State.
SJMWS owns and operates four groundwater wells in the NSJ/Alviso service area (Figure 4) with a combined pumping capacity of approximately 6,000 gallons per day (gpm). Two of the wells are currently permitted to be used under normal conditions to supply water, and the other two are available for emergency use purposes. The wells extract groundwater from the Santa Clara Subbasin – Santa Clara Plain.
Figure 4. SJMWS Well Locations
Water Supply Assessment – Seely Avenue Mixed Use Project
Duffy and Associates 9 August 2022
3.4. Recycled Water
The City of San José operates the SBWR system and distributes recycled water generated by the San José/Santa Clara Regional Wastewater Facility (RWF). Some of this water is supplied to Valley Water’s adjacent Silicon Valley Advanced Water Purification Center, which in turn purifies a small portion of the water with advanced technologies and blends it with tertiary treated water to create high quality recycled water that can be used by a wider variety of customers. Since March 2014, the purification center has been demonstrating the effectiveness of the advanced treatment technologies (microfiltration, reverse osmosis, and advanced oxidation) and setting the stage for Valley Water to begin a potable reuse program.
The SBWR program delivers disinfected tertiary treated wastewater from the RWF through an extensive recycled water distribution system consisting of over 150 miles of pipeline. The recycled water is used for non‐potable purposes such as agriculture; industrial cooling and processing; and irrigation of golf courses, parks, and schools. During the peak summer season, SBWR diverts between 15 and 20 million gallons per day (MGD) of recycled water for irrigation and industrial uses to over 900 customers throughout San José, Santa Clara, and Milpitas.
The SBWR Strategic Plan includes 15,000 AFY of retail recycled water deliveries. Although the SBWR retailer projections for recycled water exceed the amount projected in the strategic plan, total system capacity exists to meet projections.
Water Supply Assessment – Seely Avenue Mixed Use Project
Duffy and Associates 10 August 2022
4 SECTION 4. EXISTING WATER DEMANDS
4.1. Current & Future Demands
Table 5 provides the historical (actual) water use data for the SJMWS for various water use categories (e.g., single‐family, multi‐family, industrial, institutional, and others) for 2020.
Table 5. Demands for Potable and Non‐Potable Water ‐ Actual Use Type 2020 (AFY)
Single Family 7,920
Multi‐Family 2,694
Commercial 1,040
Industrial 1,837
Institutional/Governmental 176
Landscape 2,873
Losses 1,006
Recycled 4,097
TOTAL 21,643
The projected water demand for SJMWS from the 2020 UWMP, as shown in Table 6, indicates that SJMWS anticipates significant growth in demand from 2020 to 2045.
Table 6. SJMWS Projected Potable and Non‐Potable Water Demand Use Type Projected Water Use (AFY)
2025 2030 2035 2040 2045
Single Family 9,107 10,293 10,917 12,338 12,621
Multi‐Family 2,932 3,171 3,463 3,763 3,849
Commercial 1,642 1,920 2,436 3,376 3,446
Industrial 2,562 3,197 4,086 5,546 5,665
Institutional/Governmental 208 239 286 356 365
Landscape 3,401 3,930 4,586 5,584 5,712
Losses 1,228 1,406 1,569 1,852 1,894
Non‐Potable (Recycled) 4,776 5,456 6,279 7,368 7,413
TOTAL 25,856 29,612 33,622 40,183 40,965
Water Supply Assessment – Seely Avenue Mixed Use Project
Duffy and Associates 11 August 2022
Figure 5. Projected SJMWS Water Demand
4.2. Single Dry Year Supplies and Demands
As described in Valley Water’s draft 2020 UWMP, imported and groundwater supplies appear to be sufficient to meet demands during a single dry year through 2045. This assumes that reserves are at healthy levels at the beginning of the year and that the projects and programs identified in their Water Supply and Infrastructure Master Plan are implemented. If reserves are low at the beginning of a single dry year, Valley Water could call for water use reductions in combination with using reserves. Imported supplies from SFPUC during a single dry year are projected to be reduced based on their supply reliability analysis. The projected SFPUC supply available to San José in a single‐dry year ranges from 54‐64% through 2045. Accounting for total water supply management, this represents a total SJMWS potable supply shortage of under 10% in any given year, which will be managed utilizing conservation measures as identified in SJMWS’ Water Shortage Contingency Plan.
45,000
40,000
35,000
30,000
25,000
20,000
15,000
10,000
5,000
‐
2025
2030
2035
2040
2045
Potable
Recycled
Water Demand (AFY)
Water Supply Assessment – Seely Avenue Mixed Use Project
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Table 7 illustrates the reliability of water supplies to meet projected annual potable water demands for the SJMWS in a single‐dry year.
Table 7. Single Dry Year Supply and Demand Comparison (Potable) (AFY) 2025 2030 2035 2040 2045
Supply totals 19,265 22,330 25,505 30,977 31,257
Demand totals 21,080 24,156 27,342 32,814 33,553
Difference (1,815) (1,826) (1,837) (1,837) (2,296)
Note: Table Excludes recycled water which is 100% available in all years
4.3. Multiple Dry Years Supply and Demand
The greatest challenge to water supply reliability is multiple dry years, such as those that occurred in 1987 through 1992 and in 2012 through 2015. Multiple dry year periods have the potential to deplete supply reserves in, including local groundwater storage.
With existing and planned projects presented in 2020 their Water Supply Master Plan, and under current regulations, Valley Water has identified that their diverse water supplies are sufficient throughout the full five‐year drought in all demand years (Valley Water, 2021).
Projected supplies available to San José from SFPUC during multi‐dry years range from 46%‐ 64% each year through 2045. Based on cumulative available water supplies, this represents a total SJMWS potable supply shortage between approximately 5‐10% during a given multi‐dry year, which will be managed utilizing conservation measures as identified in SJMWS’ Water Shortage Contingency Plan. Table 8 presents the projected multiple‐dry year potable water supply and demand assessment for the SJMWS.
Water Supply Assessment – Seely Avenue Mixed Use Project
Duffy and Associates 13 August 2022
Table 8. Multiple Dry Year Supply and Demand Comparison (Potable) (AFY) 2025 2030 2035 2040
First Year
Supply Totals 19,265 22,330 25,505 30,977
Demand Totals 21,080 24,156 27,342 32,814
Difference (1,815) (1,826) (1,837) (1,837)
Second Year
Supply Totals 19,421 22,508 26,140 30,666
Demand Totals 21,695 24,793 28,437 32,962
Difference (2,274) (2,285) (2,297) (2,296)
Third Year
Supply Totals 20,036 23,145 27,235 30,813
Demand Totals 22,310 25,431 29,531 33,110
Difference (2,274) (2,286) (2,296) (2,297)
Fourth Year
Supply Totals 20,652 23,783 28,329 30,636
Demand totals 22,926 26,068 30,626 33,258
Difference (2,274) (2,285) (2,297) (2,622)
Fifth Year
Supply Totals 21,267 24,420 29,200 30,784
Demand Totals 23,541 26,705 31,720 33,405
Difference (2,274) (2,285) (2,520) (2,621)
Notes: 1. Supply Totals include projected supplies available from SFPUC and Valley Water (which includes groundwater) during five‐year shortages ranging from 2025‐2030 through 2040‐2045. 2. Table excludes recycled water which is 100% available in all years
5 SECTION 5. SUPPLY SUFFICIENCY ANALYSIS
The projected potable water demand of the Project is 594 AFY which represents 12% of the 5,041 AFY currently delivered to SJMWS by SFPUC in a normal water year per the WSA. The project demand represents 3% of the total SJMWS potable water demand in 2020 and 2% of the projected potable water demand in 2045. The potable water demands of the project fall within the projected water demands for SJMWS through 2045.
A condition of project approval by the City will be the construction of a domestic water supply well at the project site to meet the demands of the Project. Based on yield of other domestic supply wells in the vicinity of the Project, a well‐constructed at the site would be expected to yield approximately 1,800 gpm. Based on a 50% annual use factor, the well would yield 1,452 AFY, or 2.4 times project demand. The installation of a well with an anticipated yearly yield of 1,452 AF would provide 858 AFY of potable water more than the project demands. Potable water shall only be used for domestic purposes.
Figure 6 depicts the total projected SJMWS potable water supply and demand with Project supply and demand included.
Water Supply Assessment – Seely Avenue Mixed Use Project
Duffy and Associates 14 August 2022
Figure 6. Projected SJMWS and Project Potable Water Supply and Demand Table 9 provides a summary of projected SJMWS water supplies through 2045, the supply from the well to be constructed as part of the project, projected SJMWS and Project potable water demand, and the projected remaining potable water remaining for other uses during a normal water year.
Table 9. Projected SJMWS Potable Demand and Supply with Project Demand and Supply (AFY)
2025 2030 2035 2040 2045
Projected SJMWS Demand 21,080 24,156 27,343 32,815 33,552 Project Demand 594 594 594 594 594
Total Projected Demand 21,674 24,750 27,937 33,409 34,146 Projected SJMWS Supply 21,080 24,156 27,343 32,815 33,552 Projected Supply from Project Well 1,452 1,452 1,452 1,452 1452 Total Projected Supply 22,532 25,608 28,795 34,267 35,004 Available Remaining Potable Water
for Development (Normal Year) 858 858 858 858 858
Water Supply Assessment – Seely Avenue Mixed Use Project
Duffy and Associates 15 August 2022
Table 10 presents the projected normal, single, and multiple‐dry year water supply and demand scenarios for the SJMWS including the Project demand and supply from the Project Well. In a multi‐ year drought, Valley Water would likely implement a combination of countywide short‐ term water use reductions, use of reserves, and obtaining additional supplement supplies through transfers and/or exchanges to meet demands. Additional supply could also be developed with longer run times or higher pumping rates of the Project well and additional supplies from existing SJMWS wells and SJMWS wells currently in development to meet supply deficits.
Table 10. Normal, Single, and Multiple Dry Year Potable Water Supply and Demand Projections (AFY)
Normal Year
(2040)
Single Dry
Year
Multiple Dry Years
Year 1 Year 2 Year 3
Total Demand (Including
Project) 34,267 32,449 32,449 32,118 32,265
Total Supply (Including
Supply from Project Well) 33,409 33,408 33,408 33,556 33,704 Difference 858 ‐959 ‐959 ‐1,438 ‐1,439
Difference Made up with
Conservation and
Groundwater
0 959 959 1,438 1,439
The projected recycled water demand for the project is 13 AFY which represents 0.3% of the total projected recycled water supply for 2020 and 0.2% for 2045. Recycled water is assumed to be available in all years. The Project recycled water demand and projected available recycled water is summarized in Table 11. A condition of project approval will be that the project connect to and be served by the SBWR system.
Table 11. Normal Year Supply and Demand Comparison (Recycled) (AFY) 2025 2030 2035 2040 2045
Total Demand 13 13 13 13 13
Total Supply 4,776 5,456 6,279 7,368 7,413
Available Remaining Recycled Water 4,763 5,443 6,266 7,355 7,400
Water Supply Assessment – Seely Avenue Mixed Use Project
Duffy and Associates 16 August 2022
APPENDIX A. REFERENCES
San José Municipal Water System 2020 Urban Water Management Plan, June 2021 Valley Water Groundwater Condition Report, Santa Clara County, March 2022 Valley Water 2020 Urban Water Management Plan, June 2021