California desalination plant may help ease Colorado River water shortages

San Diego County's Water Authority approved an initial agreement to explore selling some Colorado River water to Arizona and Nevada, drawing on supplies tied to the Carlsbad desalination plant; further approvals from regional and federal agencies are required.

San Diego County's Water Authority has approved an initial agreement to explore selling some of its Colorado River water to agencies in Arizona and Nevada. The proposal would rely in part on supplies tied to the Claude "Bud" Lewis Carlsbad Desalination Plant and other water investments the county has made. Reservoir levels on the Colorado River have fallen over the last 25 years as drought and climate trends have reduced river flows. The agency says revenue from potential sales would be used to lower costs for local ratepayers. Key points: - The Water Authority's board voted unanimously to consider a memorandum of understanding to sell water across state lines. - Any interstate sales would first need approvals from the Metropolitan Water District of Southern California, the federal government and agencies in Arizona and Nevada, followed by detailed negotiations. - The authority serves as a wholesaler to 22 local agencies and about 3.3 million people and has a 30-year purchase agreement for desalinated water from the Carlsbad plant. - The Carlsbad Desalination Plant has supplied water since 2015 and is currently operating below full capacity, with the potential to increase output. - The Water Authority said it could sell up to 10,000 acre-feet starting next year, with a possible increase to around 25,000 acre-feet in future years if investments are made. - Officials describe the plan as a way to manage water resources regionally rather than along political boundaries. Summary: If the necessary regional and federal approvals are secured and details are negotiated, the arrangement could enable the first interstate transfers of Colorado River water as soon as next year. The volumes proposed would be small relative to the wider shortfall on the river, but officials say the move could demonstrate a path for cooperation among states. The next formal steps include a vote by the Metropolitan Water District and reviews by federal and out-of-state agencies.