Board Approves Next Phase of Regional Water Conveyance System Study

November 24, 2020

The Water Authority’s Board of Directors on Nov. 19, 2020, authorized the next phase of a study assessing options for long-term water deliveries to sustain the San Diego region’s economy and quality of life.

The decision followed months of community dialogue about Phase A of the Regional Conveyance System Study, which was released in August. The study demonstrated the technical viability and economic competitiveness of two routes for an aqueduct to transport the Water Authority’s independent, high-priority Colorado River water to San Diego County.

Water Authority staff will undertake Phase B over 15 to 18 months. Phase B will focus on economic analysis of the two conveyance route alternatives and exploring partnerships that could provide significant benefits to an array of stakeholders and potentially reduce the cost of project development. At the end of Phase B, the 36-member Board will again decide whether to continue with regional conveyance planning – and if so, how to proceed.

Half of the Water Authority’s supplies are from two landmark 2003 water conservation agreements – one that boosted water-use efficiency in collaboration with the Imperial Irrigation District and another to line sections of the All-American and Coachella canals with concrete to reduce seepage. Both agreements are part of the 2003 Quantification Settlement Agreement, the largest ag-to-urban water transfer in U.S. history

Conserved water from the QSA is transferred to San Diego County through an Exchange Agreement with the Los Angeles-based Metropolitan Water District of Southern California. MWD owns the only facilities available to transport large amounts of Colorado River water to San Diego County. The cost of using MWD facilities to deliver the Water Authority’s QSA water has increased 30% over the past five years.

The Water Authority’s Exchange Agreement with MWD ends in 2047, and the Water Authority is working to develop conveyance alternatives to manage future costs and risks.

To address the cost and risk uncertainties associated with the use of MWD water deliveries, the Water Authority’s Board in June 2019 approved a study of the viability of a new regional conveyance system that would deliver water from the Colorado River to San Diego County and also could provide multiple benefits across the Southwest. Three potential pipeline routes were studied in Phase A, which concluded in August 2020 that two alternatives (3A and 5A) are cost-competitive with other options, such as continued reliance on MWD.

Water Authority staff and consultants began in August to extensive series of briefings and outreach on Phase A results and consultant reports. The Board’s goal was to ensure a full exchange of information and viewpoints in a transparent process. Outreach across numerous platforms engaged member agencies, other local stakeholders, the Imperial Valley, and Borrego Springs.

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

To learn more about the Regional Conveyance System Study or to read the executive summary and the full report, go to