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Public Utilities

Water Supply

City of San Diego Sutherland ReservoirCity of San Diego Sutherland ReservoirAn adequate and reliable water supply is vital for all of us. Historically, the City of San Diego’s water needs have greatly outpaced the local supply from rain. The City purchases approximately 85% to 90% of its water, which is imported from Northern California and the Colorado River.

The City's Public Utilities Department actively pursues ways to increase our local water supply and our options. This includes maximizing all local alternatives and collaborating with other agencies and regional partners.

Water Management Plans

The City's 2020 Urban Water Management Plan (UWMP) serves as an overarching integrated water resources planning document for residents, businesses, interest groups and public officials. This plan provides information on current and future water demands and supplies, discusses water resources challenges and summarizes major initiatives that the City has proactively taken to ensure a safe, reliable water supply for its water customers.

The City’s 2020 UWMP is an update to the 2015 UWMP and was prepared in response to California Water Code Sections 10610 through 10656 of the Urban Water Management Planning Act. Included in the 2020 plan is detailed information about the City’s water demand, supply and reliability projections for the next 20 years.

The City also participates in regional water planning efforts like the Integrated Regional Water Management (IRWM) Plan, which is a collaborative effort aimed at developing long-term water supply reliability, improving water quality and protecting natural resources; and the San Diego Watershed Basin Study, which is a collaboration with the U.S. Bureau of Reclamation to assess the region’s water supply and demand and determine the potential effects from climate change impacts within the San Diego planning region.

Surface Water

The City of San Diego owns and manages PDF icon nine surface water reservoirs. The reservoirs capture local runoff from rainfall and store purchased imported water that is sent to the City’s three water treatment plants for treatment and distribution. These reservoirs currently store about 300,000 acre-feet of water and provide approximately 10% of the City’s total water supply. The City’s raw water system also includes management of over 40,000 acres of lands which are managed for source water and natural resource protection. Click here for more information about the City's reservoirs.

Recycled Water

Recycled water gives San Diego a dependable, year-round and locally controlled water resource for non-potable purposes. The City of San Diego water reclamation plants treat wastewater to a level that is approved for irrigation, manufacturing and other non-drinking or non-potable purposes.

Pure Water

The Pure Water Program is an example of City water supply diversification. The Pure Water Program is a multi-year, multi-phased water and wastewater capital improvement program that is expected, upon full implementation by the end of 2035, to have the capacity to create 83 million gallons per day of locally controlled water. Advanced water purification technology will be used to produce potable water from recycled water. The Pure Water Program will divert treated wastewater from the Point Loma Wastewater Treatment Plant’s ocean outfall and recycle a valuable and limited resource that is currently discharged to the ocean.


The Public Utilities Department is studying groundwater basins for municipal water supply and other beneficial uses. There are five groundwater basins in San Diego and the City currently uses 100 acre-feet per year from wells in the San Diego River Valley Groundwater Basin.

Additionally, the City is preparing a Groundwater Sustainability Plan for the San Pasqual Valley Groundwater Basin. This plan will ensure groundwater resources are managed to prevent chronic depletion of groundwater, reduction of storage, degradation of water quality or depletion of surface water.

For the latest information on the development of the groundwater sustainability plan for the San Pasqual Valley Groundwater Basin, visit the county of San Diego's website at

Water: From Source to Tap

The City's Public Utilities Department co-funded and helped design an exhibit at the Reuben H. Fleet Science Center where you can learn about the sources of San Diego’s water and the methods of delivering and processing this vital resource. For more information, visit the Fleet Science Center's website.