San Franciscans enjoy great drinking water from the Hetch Hetchy Regional Water System, and to protect our precious water from disruption of supply due to climate change, drought and natural disaster, we must develop new high-quality local water sources and diversify our water supplies. That’s why the City is taking steps to supplement our water supplies through groundwater wells, recycled water for irrigation and an aggressive water conservation program. We have also developed guidelines for the use of graywater through the Laundry to Landscape program.
Using local water sources reduces the vulnerability that comes from being heavily dependent on distant reservoirs, while at the same time limiting the amount of water we need from the Tuolumne River and keeping our commitment to protect and preserve our watersheds.
• SFPUC Water Resources 2012-13 Annual Report
Urban Water Management Plan
On June 14, 2011, the SFPUC adopted the 2010 Urban Water Management Plan (UWMP) for the City and County of San Francisco. The 2010 UWMP update includes county-wide demand projections to the year 2035, compares available water supplies to meet demands and presents water demand management measures to reduce long-term water demand. Additionally, the UWMP update includes a discussion of the conservation requirement set forth in Senate Bill 7 (SBx7-7) as passed in November 2009 mandating a statewide 20% reduction in per capita water use by 2020. The updated UWMP includes a quantification of the SFPUC's water use reduction targets and plan for meeting these objectives.
Potable Offset Investigation
The Potable Offset Investigation evaluates the “maximum achievable” reduction in Hetch Hetchy Regional Water System demand in San Francisco through the use of onsite supplies. The Investigation builds on the 2010 UWMP update for San Francisco by identifying opportunities to offset potable demands through the expanded use of on-site alternative supplies (including rainwater, seepage water, graywater, and blackwater) by customer class (single-family, multi-family, and non-residential) through 2035.
Water Supply Assessments
Water Code Sections 10910-10915 provide a nexus between the regional land use planning process and the environmental review process. The law also reflects the growing awareness of the need to incorporate water supply and demand analysis at the earliest possible stage in the land use planning process. The core of this law is a water supply assessment (WSA) of whether available water supplies are sufficient to serve the demand generated by projects of a specified size (“water demand projects”), as well as the reasonably foreseeable cumulative demand in the region over the next 20 years under a range of hydrologic conditions.
Under Water Code Section 10912(a), a water demand project means any of the following:
- A proposed residential development of more than 500 dwelling units.
- A proposed shopping center or business establishment employing more than 1,000 persons or having more than 500,000 square feet of floor space.
- A proposed commercial office building employing more than 1,000 persons or having more than 250,000 square feet of floor space.
- A proposed hotel or motel, or both, having more than 500 rooms.
- A proposed industrial, manufacturing, or processing plant, or industrial park planned to house more than 1,000 persons, occupying more than 40 acres of land, or having more than 650,000 square feet of floor area.
- A mixed-use project that includes one or more of the projects specified in this subdivision.
- A project that would demand an amount of water equivalent to, or greater than, the amount of water required by a 500 dwelling unit project.
The SFPUC is working in close coordination with the SF Planning Department to complete WSAs for qualifying projects. Please check in with the Environmental Planning staff assigned to your CEQA documents for further information.
Water Supply Assessments (WSA) approved by the Commission: