Enhancing Water Supply Reliability

A safe, reliable water supply is crucial for the vitality of the San Diego region’s $220 billion economy and quality of life for 3.3 million residents. To maximize the reliability of those supplies, the Water Authority is executing a long-term strategy to diversify its water 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. 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 31 percent.


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

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

The Water Authority also has secured new imported water supplies through a 45- to 75-year water conservation-and-transfer agreement with the Imperial Irrigation District. The deal, reached in 2003, will provide 70,000 acre-feet of highly reliable Colorado River water in 2010 and increases to 200,000 acre-feet annually by 2021. In addition, the Water Authority has a separate 110-year agreement to receive Colorado River water conserved by lining sections of the Coachella and All-American canals. These projects provide 80,000 acre-feet of water to the region annually.

Improving Infrastructure

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 amount used by two single-family households of four people for a year.

The Water Authority also is in the final stages of executing a $3.1 billion Capital Improvement Program to improve regional water delivery and storage capacity. The program includes dozens of projects, including new reservoirs, pipelines, pump stations and a regional water treatment facility. The work includes raising San Vicente Dam in East County by 117 feet to provide more than 157,000 acre-feet of additional local storage.

Promoting Conservation

In addition to developing new water supplies, the region needs to use existing water resources as efficiently as possible. That’s why conservation has been a key component of the Water Authority’s supply diversification strategy for the past 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 promote conservation as a way of life.

Conservation information is available at WaterSmartsd.org.