Enhancing San Diego County’s Water Supply

In 1991, the San Diego region was 95% 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 31 percent.

Consequently, the San Diego County Water Authority approved a strategy to 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%.

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. Additionally, 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.

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.