December 30, 2016
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Desalination Plant Anniversary Bodes Well for California

The one-year anniversary of Carlsbad desalination plant provides an opportunity to look at its positive impact in the region, writes Mark Muir of the San Diego County Water Authority.

By Mark Muir,

WHEN THE NATION’S largest seawater desalination plant started commercial production last December, it was a historic victory for San Diego County and an entire drought-weary state.

One year later, the Claude “Bud” Lewis Carlsbad Desalination Plant has produced nearly 15 billion gallons (57bn liters) of drinking water, representing the best of our collective efforts in California to solve complex and sometimes confounding water challenges.


  • The plant generated about 10 percent of San Diego County’s water supply during its first year, providing a valuable resource during one of the most severe droughts in modern California history.
  • It reduced state emergency water-use mandates across San Diego County in March, and helped the county pass the state’s stringent water supply stress test in June – ending the state’s emergency water-use mandates in the region.
  • It was heralded as the International Desalination Plant of the Year by Global Water Intelligence for “the most impressive technical or ecologically sustainable achievement in the industry” and by the San Diego County Taxpayers Association for “stretching taxpayer dollars through cooperation between the public and private sectors.”

What’s often overlooked is that the Carlsbad plant also relieved pressure on the State Water Project and the ecologically sensitive Sacramento-San Joaquin Bay Delta by reducing the amount of imported water San Diego County needs. The plant is a core supply for decades regardless of the weather. Every drop it produces is a drop that we don’t need to import from sources impacted by long-term drought.

In fact, the Carlsbad plant underscores San Diego County’s long-running commitment to support water-management efforts statewide. Gov. Jerry Brown’s 2014 California Water Action Plan says California should make conservation a way of life, advance regional self-reliance and manage and prepare for dry periods.

More than two decades ago, the San Diego region adopted a strategic, multifaceted water strategy for managing both supply and demand, embracing the core concepts of the governor’s water plan well before it was conceived. Even though seawater desalination makes headlines, it’s just one piece of our approach that includes continuing to increase water-use efficiency.

Prior to emergency water-use mandates imposed by the state in 2015, San Diego County’s per capita potable water use was nearly 40 percent below 1990 levels. In fact, the region’s population grew by 800,000 and its economic output nearly doubled between 1990 and 2015, while total potable water use declined by more than 20 percent.

Even though the Carlsbad plant helped to ensure that we would have sufficient water to meet demands in 2016 (and beyond), the San Diego region beat the state’s emergency targets to reduce water use by 20 percent. Once state targets were lifted, San Diego kept conserving at an impressive pace; urban potable water use for the region was down 17 percent from June through October 2016, compared to the same period in 2013.

From its earliest days, California has embraced a spirit of innovation in the face of challenges, and that same spirit will be necessary in the years ahead. The one-year anniversary of the Carlsbad desalination plant invites us to remember how far we’ve come as a region and a state to manage existing water supplies wisely, while advancing new and bold water solutions that will secure our future.

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