Nation’s Largest Seawater Desalination Plant Delivers 40 Billion Gallons of High-Quality Drinking Water

December 13, 2018

Project partners Poseidon Water and the San Diego County Water Authority gathered today at the Claude “Bud” Lewis Carlsbad Desalination Plant to celebrate delivering 40 billion gallons of drought-resilient drinking water to San Diego County during three years of commercial operations at the plant. The short ceremony included a proclamation by Supervisor Bill Horn marking Dec. 13, 2018, as Claude “Bud” Lewis Carlsbad Desalination Plant Day, and a ceremonial toast with desalinated water.

“It’s incredible what we’ve accomplished in three years,” said Sandra Kerl, deputy general manager of the Water Authority. “Since coming online in 2015, the Carlsbad Desalination Plant has met nearly 10 percent of the region’s water demand, and it will be a core water resource for decades to come.”

The Carlsbad Desalination Plant provides San Diego County with more than 50 million gallons of high-quality, locally controlled, water every day. It’s a foundational water supply for the county that minimizes the region’s vulnerability to drought or other water supply emergencies. The Carlsbad plant also is the largest, most technologically advanced and energy-efficient desalination plant in the nation.

“This pioneering project continues to be a shining example of innovation and a vital resource for the San Diego region,” said Poseidon Water CEO Carlos Riva. “We are proud of our role in the San Diego region and look forward to continued success and partnership with the community.”

The Carlsbad Plant is the result of a 30-year Water Purchase Agreement between the plant’s developer and owner, Poseidon Water, and the Water Authority for the production of up to 56,000 acre-feet of water per year. It is a major component of the Water Authority’s multi-decade strategy to diversify the region’s water supply portfolio.

“To think that three short years ago we were here for the opening of plant operations, and today we are celebrating 40 billion gallons of water delivered is truly inspiring,” said Mayor Matt Hall of Carlsbad, who serves on the Water Authority’s Board of Directors. “Poseidon Water has been a remarkable partner not only by enhancing our region’s water supply reliability but also improving our regional quality of life by protecting and preserving our coastal environment.”

Poseidon Water and the Water Authority were joined at the event by former U.S. Senator Barbara Boxer; Carlsbad Mayor Matt Hall, Mayor Pro Tem Keith Blackburn, Council Member Priya Bhat-Patel; and representatives from the offices of California Senator Patricia Bates, San Diego County Supervisor Bill Horn and the California Pollution Control Financing Authority, among others.

The desalination plant sits on six acres next to the Encina Power Station on land owned by NRG, a Fortune 200 energy company. NRG is in the process of shutting down and decommissioning the power station, and the desalination plant will convert to an independent operation over the next few years. it will be the first desalination plant to comply with the 2015 California Ocean Plan Amendment to advance ocean water as a reliable supplement to traditional water supplies while protecting marine life and water quality. Additionally, Poseidon Water is protecting and preserving the coastal environment by preparing to take over NRG’s responsibilities as the steward of the Agua Hedionda Lagoon and responsibility for its ongoing preservation.

For more information, go to the plant website,, or to the Water Authority’s website,

  • The San Diego County Water Authority sustains a $268 billion regional economy and the quality of life for 3.3 million residents through a multi-decade water supply diversification plan, major infrastructure investments and forward-thinking policies that promote fiscal and environmental responsibility. A public agency created in 1944, the Water Authority delivers wholesale water supplies to 23 retail water providers, including cities, special districts and a military base.

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    Grace Sevilla

    Phone: (619) 855-5135