Water Supplies

A safe, reliable water supply is crucial for the vitality of the San Diego region’s economy and quality of life of its residents. The San Diego County Water Authority is working to enhance reliability of the water supply to meet the region’s growing demands and to ensure the cost effective, environmentally sensitive, and safe delivery of those supplies. To maximize the reliability of the region’s water supply, the Water Authority is executing a long-term strategy to diversify the region's supply sources, make major investments in the region’s water delivery and storage system, and improve water-use efficiency.


Supply Diversification

In 1991, the San Diego region was 95 percent reliant on a single supplier of imported water – the Metropolitan Water District of Southern California (MWD). This made the region extremely vulnerable to water supply shortages. That year, an ongoing drought forced MWD to cut deliveries to the San Diego region by 30 percent.

Regional Water Supply Portfolio Diversificationsupply diversification
Click image above to enlarge.

As a result of that crisis, the Water Authority Board approved a strategy to aggressively diversify its water supply portfolio by developing new local and imported water supplies. This strategy already is enhancing regional supply reliability. By fiscal year 2012, the San Diego region had reduced its reliance on MWD supplies to 45 percent. 

The Water Authority is working with its 24 local member retail agencies to develop local supplies such as groundwater, recycled water, seawater desalination, and conservation. By 2020, local water supplies are projected to meet 36 percent of the region’s water demand.

The Water Authority also has secured new imported water supplies through a long-term (45 to 75 years) water conservation and transfer agreement with the Imperial Irrigation District. The deal, reached in 2003, will provide 100,000 acre-feet of highly reliable Colorado River water in 2013 and increases to 200,000 acre-feet annually by 2021.

The Water Authority also has a separate, 110-year agreement to receive Colorado River water conserved by lining parts of the Coachella and All-American canals. These projects provide 80,000 acre-feet of water to the region annually.

What is an Acre-Foot?

An acre-foot is 325,900 gallons – roughly enough to submerge an entire football field a foot deep. It's approximately the supply used by two single-family households of four people for a year.

Improving Infrastructure

San Vicente Dam rendering
The San Vicente Dam Raise project will be completed by 2014.

The Water Authority also is in the final stages of executing a $3.1 billion Capital Improvement Program to further improve regional water delivery and storage capacity. The program includes 50 different projects, including new reservoirs, pipelines, pumping stations and a regional water treatment facility. Major projects under way include raising San Vicente Dam in East County by 117 feet to provide 152,100 acre-feet of additional local storage.



Promoting Conservation

Water-efficient landscapes help stretch the region's water supply.

In addition to developing new water supplies, it makes sense for the region to use its existing water resources as wisely and efficiently as possible. That’s why conservation has been a key component of the Water Authority’s supply diversification strategy for the last two decades. The Water Authority works with its member agencies and other partners to offer programs that improve water use efficiency for residential, commercial, and agricultural users and help promote conservation as a way of life in the San Diego region.

Conservation tips and program information is available at watersmartsd.org.

Colorado River
The Water Authority imports more than 70 percent of the region's water supplies. The Colorado River is the source for most of San Diego County's imported water.

This Water Authority is cost-effectively managing the region's water supply portfolio through: