Nation’s Largest Seawater Desalination Plant Marks One-Year Anniversary

December 14, 2016

In its first year of operations, the nation’s largest and most technologically advanced seawater desalination plant produced enough high-quality, drought-proof water from the Pacific Ocean to meet approximately 10 percent of the region’s demand. The Claude “Bud” Lewis Carlsbad Desalination Plant quickly generated significant benefits by relieving pressure on imported water supplies, reducing state mandates for emergency conservation measures in March and helping the region pass the state’s stringent water supply “stress test” in June.

After completing construction on schedule, the plant was dedicated on Dec. 14, 2015, in front of more than 600 elected officials, community leaders and project partners. The facility – named after the late Carlsbad mayor who also served as Water Authority Board chair – soon garnered local and international accolades. It was honored in April 2016 with a Global Water Award as the Desalination Plant of the Year by Global Water Intelligence for “the most impressive technical or ecologically sustainable achievement in the industry.” In June, the San Diego County Taxpayers Association recognized the desalination project with its highest honor – the Grand Golden Watchdog – for “stretching taxpayer dollars through cooperation between the public and private sectors.” And in July, Poseidon was named an Energy Champion by San Diego Gas & Electric (SDG&E) for its “remarkable commitment to sustainability, energy efficiency and conservation.”

During its first year, the Carlsbad plant produced nearly 15 billion gallons of fresh water – approximately 45,000 acre-feet – for the San Diego region during one of the most severe droughts in state history.

“This plant is a game-changer for San Diego County,” said Mark Muir, chair of the San Diego County Water Authority’s Board of Directors. “It’s gratifying that this visionary investment our region’s ratepayers strongly supported is paying dividends now, and we expect it to continue to do so for decades to come.

“The desalination plant also underscores our region’s commitment to reducing reliance on imported water from the Sacramento-San Joaquin Bay-Delta and meeting the objectives of the state’s Water Action Plan. Every drop of water we produce locally is a drop that we don’t need to import from outside the region.”

The Carlsbad Desalination Plant is the result of a 30-year, public-private partnership 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 – enough to meet the needs of approximately 400,000 people. It is a major component of the Water Authority’s multi-decade strategy to diversify the region’s water supply portfolio.

The $1 billion desalination project includes three main components: the desalination plant adjacent to NRG Energy’s Encina Power Station on Agua Hedionda Lagoon; a 10-mile pipeline that connects to the Water Authority’s regional distribution system; and upgrades to Water Authority facilities for distributing desalinated seawater throughout the region.

“This was a historic undertaking, and the plant’s first-year operation was a great success,” said Poseidon Water CEO Carlos Riva. “Seawater desalination is a viable option for coastal communities seeking to secure new, fresh water supplies. We have proven that it can be done, and are proud to mark this anniversary with our project partners at the Water Authority, IDE Technologies, Stonepeak Infrastructure Partners and Kiewit-Shea Desalination.”

Poseidon Water is a private company that partners with public agencies to deliver water infrastructure projects. The company’s primary focus is developing large-scale reverse osmosis seawater desalination plants. Poseidon is developing a second seawater desalination facility in Huntington Beach, Calif., that is in the final phase of the permitting process.

The Carlsbad plant uses reverse osmosis to produce a highly reliable supply, day-in and day-out, regardless of weather or climate conditions, and it is blended with water from other sources for regional distribution. It costs about a half-cent to produce a gallon of drinking water at the plant. Desalinated water costs typical homeowners in the region about an additional $5 per month, in line with the low end of projections when the project was approved in late 2012.

Since the drought of 1987-92, the Water Authority has transformed the region’s water supply mix through a long-term strategy to diversify its water supplies and enhance regional water infrastructure. Elements of the strategy include:

  • Implementing the nation’s largest agriculture-to-urban water conservation and transfer agreement with the Imperial Irrigation District;
  • Securing additional long-term, highly reliable Colorado River water supplies through canal-lining projects in the Imperial Valley;
  • Assisting local member agencies in developing their own local water sources; and
  • Helping reduce regional per capita potable water use by nearly 40 percent between 1990 and 2015 through legislation, education, incentives and other measures to promote conservation and water-use efficiency.

The strategy has worked so well that the San Diego region has sufficient water supplies to meet normal water demands after five years of drought, and it passed the state’s water supply “stress test” that assumes the drought will continue another three years.

Starting in the early 1990s, the Water Authority began investigating the potential for a desalination project along the county’s coastline. It identified the Carlsbad site as one of the most likely locations because of the existing seawater intake and discharge infrastructure used by the Encina Power Station and its location relative to the Water Authority’s distribution system. Poseidon Water spearheaded efforts to develop the Carlsbad site starting in the late 1990s.

  • 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.

    Media Contact Information

    Grace Sevilla

    Phone: (619) 855-5135