One Water Plan

One of the City Council’s priorities for 2024 is Climate Change & Natural Environment - Protection & Adaptation. The City is working on its "One Water Plan," which is a key action in the City's Sustainability and Climate Action Plan (S/CAP) that will identify possible alternatives for meeting the community’s water needs in the future.

Background

Palo Alto’s Water Supply and Conservation

The City of Palo Alto receives 100% of its potable water from the San Francisco Hetch Hetchy Regional Water System (RWS), operated by the San Francisco Public Utilities Commission (SFPUC). The City also uses some recycled water produced at the Palo Alto-operated Regional Water Quality Control Plant (RWQCP) for irrigating the municipal golf course, a park, and other minor applications. A system of local groundwater wells and storage provide emergency water supply service. The City also partners with Valley Water to offer a wide range of water conservation programs to the community.

Water Supply Reliability

Since Palo Alto relies on the Regional Water System (RWS) for its potable water supplies, Palo Alto’s current water supply reliability mirrors that of the RWS. Palo Alto needs to carefully consider the vulnerabilities and resilience of the RWS in its own water supply planning efforts. The One Water Plan will consider uncertainties, such as water demand, drought conditions and the implementation of the Water Quality Control Plan for the San Francisco Bay/Sacramento-San Joaquin Delta Estuary (Bay Delta Plan Amendment or Bay Delta Plan). The Palo Alto City Council voted to support the Bay Delta Plan Amendments and the SWRCB adopted the amendments in 2018. A key driver of the One Water Plan is to study the feasibility of implementing alternative water supply sources to reduce reliance on the RWS and to increase water supply reliability for Palo Alto.

Similar to Palo Alto’s One Water Plan, the SFPUC has initiated an Alternative Water Supply Planning program to ensure that San Francisco can meet its Retail and Wholesale Customer water needs, address projected dry year shortages, and limit rationing to a maximum 20 percent system-wide in accordance with adopted SFPUC policies.

Scope

• Develop a One Water Plan that compares potential water supply and water conservation portfolios using weighted evaluation criteria
• Develop an Excel-based tool that Palo Alto can use to evaluate and prioritize water supply and water conservation portfolios now and as future uncertainties are resolved.

Timeline

One Water Plan – Existing Plans, and Effluent Transfer Agreement

The One Water Plan will leverage existing completed and in-progress plans to evaluate alternative water supplies with the potential to make Palo Alto’s water supply more resilient. These plans include:

  • Northwest County Recycled Water Strategic Plan, completed by Palo Alto together with Valley Water and the City of Mountain View, sought to identify the most appropriate ways to expand the City of Palo Alto’s Recycled Water Program. The Northwest County Recycled Water Strategic Plan was accepted by Palo Alto City Council in 2020 (Council Report #10913(PDF, 8MB) ). Visit the Recycled Water Pipeline & Strategic Plan Website.
  • A detailed Groundwater Assessment, completed as part of the Northwest County Recycled Water Strategic Planning efforts, characterized the hydrogeologic conditions in Palo Alto and surrounding areas as well as evaluated the feasibility of increased groundwater pumping by Palo Alto and refined the estimate of groundwater yield available to Palo Alto.
  • Green Stormwater Infrastructure (GSI) Plan(PDF, 23MB) describes how the City will gradually integrate GSI features into its urban landscape and storm drain system over several decades. While the primary purpose of GSI is stormwater pollution control, GSI also represents a water supply option. The One Water Plan will consider this possibility.
  • In 2019 Council approved an Effluent Transfer Agreement with Valley Water and the City of Mountain View (Council Report #10627). This 76-year agreement enables an effluent transfer from the Regional Water Quality Control Plant to Valley Water to be reused in Santa Clara County, likely south of Mountain View. A Council study session with Valley Water on September 12, 2022 provides updated information (Council Report #14650(PDF, 13MB) ).
  • Palo Alto’s 2020 Urban Water Management Plan & Water Shortage Contingency Plan includes an assessment of the reliability of Palo Alto’s water sources, an analysis of water demand, a description of water conservation efforts, and a water shortage contingency plan.
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