OUR MISSION: To provide our customers with high-quality, efficient and reliable water, power and sewer services in a manner that values environmental and community interests and sustains the resources entrusted to our care.
525 Golden Gate Avenue, 13th Floor
San Francisco, CA 94102
T 415.554.3155
F 415.554.3161
TTY 415.554.3488
January 31, 2025
Sue Parker Erika Contreras
Chief Clerk of the Assembly Secretary of Senate
California Legislature California Legislature
State Capitol, Room 3196 State Capitol, Room 3044
Sacramento, CA 95814 Sacramento, CA 95814
Darrin Polhemus
Division of Drinking Water, Director
State Water Resources Control Board
1001 I St., 24
th Floor
Sacramento, CA 95814
Dr. Tomás J. Aragón, M.D., Dr. P.H.
Director and State Public Health Officer
California Department of Public Health
P.O. Box 997377, MS 0500
Sacramento, CA 95899-7377
Dear Madams and Sirs:
In accordance with Assembly Bill 1823, a bill codified in Chapter 841 of the California Water Code, Section 73504(a), the San Francisco Public Utilities Commission (SFPUC) is herewith reporting on the progress it has made during 2024 in securing additional water supplies to supplement its Hetch Hetchy Regional Water System supply during dry years.
This past year, the SFPUC has continued the implementation of its water supply projects in the Water System Improvement Program (WSIP). The projects are either complete or close to completion. The dry-year water supply projects included in WSIP were designed to allow the SFPUC to meet at least 80 percent of its customer demand during droughts assuming current system supplies and operation and rationing up to no more than 20 percent in any one year of a drought. However, the SFPUC’s ability to meet its customer demand during dry years may be affected by the State Water Resources Control Board’s amendment to the Water Quality Control Plan for the San Francisco Bay / Sacramento-San Joaquin Delta Estuary (Bay-Delta Plan Amendment), which was adopted in December 2018. The Bay-Delta Plan Amendment calls for the release of 40% of the unimpaired flow in the Tuolumne River from Don Pedro Reservoir. The SFPUC staff analysis of the Bay-Delta Plan Amendment shows that its implementation could cause a significant reduction in available water supply and an associated need to increase rationing to up to 50% during droughts in SFPUC’s service area. SFPUC staff continue to engage in negotiations with other parties and the State to reach agreement on an alternate plan referred to as the Healthy Rivers and Landscapes program.
Meanwhile, planning for new, alternative water supplies is ongoing and is described below.
The SFPUC has continued planning that was initiated in 2020 for additional water supply under the Alternative Water Supply (AWS) Program to meet future dry-year water needs in its service area. The planning efforts involve evaluating new storage and supply opportunities in the region to meet anticipated future needs. The projects outlined below are regional projects that could contribute to increasing SFPUC’s water supplies for dry years. Several of the projects described remain in the planning and feasibility study stage, requiring additional analysis and resources.
• Regional Groundwater Storage and Recovery (RGSR) Project – The RGSR Project is a strategic partnership between the SFPUC and three partner agencies: the City of Daly City, the City of San Bruno and the California Water Service Company (serving South San Francisco and Colma). The project sustainably manages groundwater and surface water resources in a way that provides supplies during times of drought. During years of normal or heavy rainfall, the project would provide additional surface water to the partner agencies in San Mateo County, allowing them to reduce the amount of groundwater that they pump from the South Westside Groundwater Basin. Over time, the reduced pumping would allow the aquifer to naturally recharge and result in increased groundwater storage of up to 20 billion gallons of new water supply available during dry years. Phase 1 of this project consisted of construction of thirteen well sites and was completed in 2022. Phase 2 has been separated into two contracts. Phase 2A consists of inspection and service of each well and existing well pumps, addition of variable frequency drives to improve efficiency, and installation of cathodic protection to address potential corrosion. The Phase 2A work anticipates achieving substantial completion by February 2025. Phase 2B consists of work at SSF Main Well and pipeline installation to connect the well to Cal Water's treatment facility.
• Daly City Recycled Water Expansion Project - This is a recycled water project that could produce approximately 1 mgd of recycled water on an average annual basis. The primary purpose of the project is to provide recycled water to local cemeteries and other smaller irrigation customers, offsetting existing groundwater pumping from the South Westside Groundwater Basin (Basin); this would free up groundwater and enhance the reliability of the Basin, supporting the RGSR Project described above.
The project is a regional partnership between the SFPUC, Daly City, and California Water Service Company's (Cal Water); the irrigation customers are located largely within Cal Water’s service area. In 2024, the SFPUC staff continued negotiations on the terms of the project with partner agencies. With the distribution of benefits among partners, the net volumetric water supply benefit to the SFPUC would be approximately 0.4 mgd. During this period, capital and long-term operating costs were also
updated resulting in a significant increase in costs to the SFPUC. Due to the increasing cost and relatively small volume of water that the project can provide, the SFPUC will be deferring this project in its capital plan in the coming year.
• Alameda County Water District-Union Sanitary District Purified Water Project - This project can provide a new purified water supply utilizing Union Sanitary District’s (USD’s) treated wastewater and further treating it through a multi-barrier advanced treatment process to meet or exceed drinking water standards. Purified water produced by USD would be transmitted to the Quarry Lakes Groundwater Recharge Area to supplement recharge into the Niles Cone Groundwater Basin or for other uses in Alameda County Water District's (ACWD's) service area. With the additional water supply to ACWD, an in-lieu exchange with the SFPUC would result in more water left in the SFPUC's Regional Water System.
Additional water supply could also be directly transmitted to the SFPUC through a new intertie between ACWD and SFPUC. In 2024, the project team finalized the feasibility study after receiving initial feedback from the US Bureau of Reclamation. Both ACWD and USD are currently undertaking planning efforts that will determine the priority level of this project.
• PureWater Peninsula Project - This purified water project could provide 6- 12 mgd of water supply through reservoir water augmentation at Crystal Springs Reservoir in San Mateo County, or through direct potable reuse into SFPUC's transmission system. Treated wastewater from Silicon Valley Clean Water and/or the City of San Mateo would go through a water purification process that uses multi-barrier treatment technology to meet state and federal drinking water quality standards. The purified water could then be transmitted to Crystal Springs Reservoir as indirect potable reuse (a Basis of Design Report for this concept was completed in 2023) or connect to SFPUC’s transmission through treated water augmentation. In addition to the SFPUC and the wastewater agencies, Cal Water, the Mid- Peninsula Water District, Redwood City and the Bay Area Water Supply & Conservation Agency (BAWSCA) are also participating directly in the project. In 2024, the SFPUC worked on outreach strategies with the partner agencies and renamed the project to PureWater Peninsula (previously titled San Francisco Peninsula Regional Purified Water Project). The SFPUC also completed a feasibility study of the alternative that would bring 12 mgd of purified water directly, through treated water augmentation, to the Regional Water System. The SFPUC is currently evaluating the water quality and operational impacts between the project alternatives.
• South Bay Purified Water Project - The SFPUC, Valley Water, the City of San Jose, and the City of Santa Clara are in the early planning stage of developing a joint purified water project that would serve the local demands
of San Jose and Santa Clara during all types of water years, while also supplementing the water supply provided through the SFPUC’s Regional Water System in dry years. An initial concept for a 10-mgd advanced water treatment facility (i.e., purified water facility) using source water from the San Jose-Santa Clara Regional Wastewater Facility was studied prior to Valley Water joining the partnership this past year. The project is currently being revised to include Valley Water, maximize utility, and ensure the critical needs of all partners are met.
• Los Vaqueros Reservoir Expansion Project - The Los Vaqueros Reservoir Expansion Project (LVE) is a storage project that would have expanded the existing reservoir located in northeastern Contra Costa County from 160,000 acre-feet to 275,000 acre-feet. The existing reservoir is owned and operated by Contra Costa Water District (CCWD), who moved to end their participation in the project in November 2024, citing rising costs and decreasing benefits. As the owner and operator of the existing reservoir, CCWD’s decision ended the project as a whole. The Los Vaqueros Reservoir Expansion Joint Powers Authority (Authority) began work to dissolve the Authority in December 2024. Had the expansion been implemented, the expanded reservoir would have increased water supply reliability for municipal, industrial, and agricultural customers as well as provided ecosystem benefits to south-of-Delta wildlife refuges and Delta fisheries. Storage in the expanded reservoir would have offered a dry-year water supply benefit to the SFPUC's Regional Water System. Prior to the announcement of the project’s end, the SFPUC worked closely with the project partners to develop the project and secure necessary permits and agreements ahead of project implementation. SFPUC representatives participated in the JPA Board of Directors, various committees, and technical, financial, operational, and legal aspects of the project. SFPUC staff will continue to support the project during the wind-up and dissolution of the Authority.
• LVE Supply Alternatives (formerly Bay Area Brackish Water Desalination) - LVE Supply Alternatives is a project to identify and secure one or more supply sources to store water in the SFPUC’s share of expanded storage in the Los Vaqueros Reservoir. In 2024, supply opportunities including desalination, groundwater demineralization, transfers, and purified water were evaluated. Although the LVE project will not proceed, the supply options assessed as part of LVE Supply Alternatives will be considered for other regional partnerships.
• Calaveras Reservoir Expansion Project - This storage project envisions the expansion of Calaveras Reservoir to store excess Regional Water System supplies or other source water in wet and normal years. No expansion of water rights from the local watershed is anticipated. With the
Calaveras Dam Replacement project in place, Calaveras Dam holds a capacity of 96,850 acre-feet, or 31 billion gallons of water. Through an expansion, up to an additional 289,000 acre-feet, or 94 billion gallons of storage could be realized. The expansion of Calaveras Reservoir would provide storage for additional water that can be available in all water year types. The proposed project would include raising the dam, increasing the capacity of the outlet structures and the spillway, and the addition of any transmission and pumping needed to bring water to Calaveras Reservoir. In 2023, SFPUC staff completed a preliminary evaluation of conveyance alternatives and associated costs. Due to the challenges of expanding conveyance in the region, planning for this project is being deferred while other alternative supply and storage projects continue to be evaluated.
In addition to the above projects that are in the planning and feasibility study stage, the SFPUC is engaged in conversations on various other projects, including new interconnections, water transfers and exchanges through the Bay Area Regional Reliability (BARR) Partnership.
The SFPUC and its Wholesale Customers also continue to advance conservation within our service areas. In addition to demand reduction measures, the SFPUC is simultaneously pursuing studies to evaluate the potential for additional recycled water and purified water in San Francisco and investing in innovation that can result in further demand reduction or supply increases, such as atmospheric water generation technology. In February 2024, the SFPUC released the Alternative Water Supply Plan, a report that takes a comprehensive view of the need for alternative water supply and storage and identifies actions for the SFPUC, including the planning of projects described in this letter. This report can be found online at https://sfpuc.gov/awsplan. Additionally, e
fforts under the Alternative Water
Supply Program are summarized in an Annual Progress Report provided to the SFPUC Commission and will continue to be reported each June.
Implementation of the WSIP dry-year projects and the pursuit of alternative water supplies to meet future needs are necessary to ensure sufficient water during droughts for our Retail and Wholesale Customers. These efforts will continue to carry the upmost importance to the SFPUC into the future.
Cordially,
Steven R. Ritchie
Assistant General Manager, Water
CC:
SFPUC: Dennis J. Herrera, General Manager
Ron Flynn, Deputy General Manager
SFPUC Commissioners
BAWSCA: Tom Smegal, CEO/General Manager
Tom Francis, Water Resources Manager