California will lose 440,000 acre-feet of Colorado River water per year starting in 2027, but San Diego County Water Authority General Manager Dan Denham says the region's locally built supply network can absorb the blow.
The U.S. Bureau of Reclamation on Friday, Aug. 21, released its Record of Decision establishing two-year operating guidelines for the Colorado River. Interior Secretary Doug Burgum signed the plan, which cuts 1.25 million acre-feet annually from the three Lower Basin states: Arizona loses 760,000 acre-feet, California 440,000 and Nevada 50,000. The reductions amount to roughly 21% of the states' combined river allocation.
The cuts could nearly double after 2028 if reservoir levels keep falling. Lake Mead stood at 27% of capacity and Lake Powell at 21% as of mid-August, according to the Denver Post.
Carlsbad plant at the center
Denham pointed to "decades of local and regional investments" in a statement posted to the authority's website Friday. He said the region has "one of the nation's most resilient and diversified water portfolios, providing stability and flexibility even in times of uncertainty."
Central to that portfolio is the Claude "Bud" Lewis Carlsbad Desalination Plant, the nation's largest seawater desalination facility. The plant produces more than 50 million gallons of drinking water per day, enough to serve about 400,000 people. It supplied roughly 9% of SDCWA's total water in fiscal year 2025, according to an S&P Global Ratings report published Aug. 19.
The Carlsbad plant also anchors a newer strategy: an interstate water exchange. SDCWA has a signed memorandum of understanding with the Arizona Department of Water Resources, the Central Arizona Water Conservation District and the Southern Nevada Water Authority to negotiate contracts that would swap credits for desalinated water, valued at about $4,000 per acre-foot, for SDCWA's Colorado River supplies. The MOU was signed at the Carlsbad plant, according to Water News Network. No capital investment would be required.
"The San Diego County Water Authority stands ready to work with Basin partners on water exchanges and transfers across state lines," Denham said in Friday's statement.
What comes next
The Record of Decision replaces operating rules that expire in October 2026 and covers only 2027 and 2028. The 10-year framework requires new operating plans every two years, with the next round of negotiations expected to begin in the coming months for the 2029-2030 period. If the seven basin states reach consensus on a longer-term agreement, it can replace the federal plan at any point.
Bureau of Reclamation assistant secretary for water and science Andrea Travnicek said the decision provides a management strategy for basin stakeholders to respond to prolonged drought through flexible tools and voluntary actions while leaving room for future consensus agreements.
Denham also cited "repurified water" as a future local supply SDCWA is developing to further reduce dependence on the Colorado River. The authority serves 22 member agencies across San Diego County.
The next two-year operating plan under the framework will be set before 2029, though no specific negotiation date has been announced. SDCWA has not posted a public comment period for the next round of Colorado River discussions.
