The San Diego County Water Authority’s Board of Directors today unanimously approved a landmark agreement to explore an interstate water transfer and exchange pilot program with the U.S. Bureau of Reclamation, the Metropolitan Water District of Southern California, and agencies in Nevada and Arizona.

The memorandum of understanding (MOU) – which still needs to be ratified by the other agencies – creates a pathway that could eventually allow the Water Authority to “move” water from the nation’s largest seawater desalination plant in Carlsbad to areas in the drought-ravaged Colorado River Basin that need more water. If successfully developed, this would create the first program to transfer water across state lines within the basin.

Such a program could help reduce water costs for working families in San Diego County by optimizing the region’s investments in reliability. Water purchases from the Claude “Bud” Lewis Carlsbad Desalination Plant would generate new revenues and offset costs for residents, improving regional water affordability.

“This agreement could be a gamechanger for San Diego County and the entire Southwest because it creates the possibility of a new, collaborative path for moving water where it’s needed most while keeping reliability and affordability at the center for ratepayers,” said Water Authority Board Chair Nick Serrano. “Leveraging existing resources like our Carlsbad desalination plant in this moment simply makes sense for everyone.”

Water transfers or exchanges would occur “on paper,” meaning agencies would access supplies through existing infrastructure and avoid costly new infrastructure.

The demand is clear: In recent years, agencies in Arizona and Nevada have sought ways to tap the Pacific Ocean, but the costs of construction are prohibitive. The Arizona Department of Water Resources, Central Arizona Water Conservation District and Southern Nevada Water Authority are part of the new MOU.

For more than 20 years, the seven states in the Colorado River Basin have wrestled with drought conditions that have created growing imbalances between water supplies and demands. As the Bureau of Reclamation, Basin States, Mexico, and tribal nations consider new operating guidelines for the river, new management strategies and interstate partnerships are increasingly critical.

Over roughly the same period, the Water Authority has invested $3 billion in water reliability efforts, including the Carlsbad plant, which produces up to 54 million gallons per day. Additionally, the 2003 Colorado River Quantification Settlement Agreement – which generates conserved water in the Imperial Valley – and hard-wired conservation in the San Diego region have positioned the Water Authority to not only meet the region’s needs but also provide relief to other areas.

“Next-generation strategies must include interstate partnerships that deliver water where it’s needed most,” said Water Authority General Manager Dan Denham. “We appreciate the collaboration with the Bureau of Reclamation, Metropolitan Water District, Arizona and Nevada. New ideas are challenging to implement, but it’s in everyone’s best interest to make this work.”