Colorado River Supplies Management

Regional Conveyance System Study Sessions

The San Diego County Water Authority hosted two online public information sessions about aspects of the proposed Regional Conveyance System in recent weeks – one on economic considerations and another about Borrego Springs. Links to the PowerPoint presentations, the webcast videos and question and answer documents are listed below.

The final RCS Study Phase A report, released by the Water Authority in August 2020, shows that building a new conveyance system to transport regional water supplies from the Colorado River Quantification Settlement Agreement is cost-competitive with other long-term strategies for meeting the region’s water needs.

Three potential pipeline routes were studied in Phase A, which says two alternatives (3A and 5A) are cost-competitive with other options, such as relying more on the Metropolitan Water District of Southern California or developing additional local supplies.

At its August 2020 meeting, the Water Authority’s Board of Directors decided to continue the discussion about regional conveyance until November, at which time the Board will take up the question of how to move ahead.

The Water Authority’s water supply portfolio includes a suite of relatively new supplies from the Colorado River. These supplies include a water transfer conservation and transfer agreement with the Imperial Irrigation District and water conserved by two projects, the All American Canal Lining Project, and the Coachella Canal Lining Project

The Water Authority will receive approximately 180,000 acre-feet of its supply from these sources in calendar year 2015. By 2020, these supplies are expected to produce approximately 280,000 acre-feet, and comprise more than 30 percent of the Water Authority’s total water supply. The chart shows the projected yield of these three projects.

The transfer and canal-lining projects were enabled by the 2003 Quantification Settlement Agreement, which allowed major water conservation and transfer programs to be implemented by California’s agricultural Colorado River contractors. The conserved water is made available for water users in Southern California’s urban coastal area, who pay for the conservation programs. 

The Water Authority continues to work with other Colorado River contractors and states to develop additional Colorado River water supplies and water management strategies. The Water Authority participated in a study by the U.S. Bureau of Reclamation of overall water demand and supply conditions in the entire seven-state Colorado River Basin, and is working together to address projected water supply and demand imbalances in the Colorado River Basin, with an eye toward augmenting limited Colorado River supplies.

Water Transfers 2003-2021

Before 2003, the Water Authority purchased all of its imported water supply from the Metropolitan Water District. The dependence upon a single supplier increased risk of water shortages. By creating large, independent supply sources from the Colorado River, the Water Authority is able to enhance its water supply reliability and minimize the risk of serious water shortages in the region. The Water Authority’s Colorado River supplies provide a strong foundation for a diverse and reliable water supply.