• Capabilities: Water Treatment and Supply, Stormwater and Green Infrastructure, Asset Management

Claude "Bud" Lewis Carlsbad Desalination Plant

Carlsbad, San Diego, USA - The Claude “Bud” Lewis Carlsbad Desalination Plant is the largest, most technologically advanced and energy-efficient seawater desalination plant in the Western Hemisphere and a model for alternative water solutions in the United States.


Million gallons of fresh drinking water per day


San Diego County residents served
Claude “Bud” Lewis Carlsbad Desalination Plant

The state of California relies on groundwater and surface water, from well-known sources like the Colorado River, to meet the needs of nearly 40,000,000 residents. In recent years, severe drought conditions have forced water officials to consider more sustainable water solutions.

Since late 2015, the residents and businesses of San Diego County have had access to a drought-proof water supply tapped right from the Pacific Ocean. The Claude “Bud” Lewis Carlsbad Desalination Plant was built to expand the County’s water portfolio during a period of great strain on the region’s resources. It provides purified water to the County as many areas of the country continue to battle drought and climate change.

Owned by Poseidon Water, the plant supplies 50 million gallons of fresh drinking water per day to 400,000 residents of San Diego County and, as part of a purchase agreement between owner and the County, will continue to do so for the next 30 years. As project partner, Arcadis provided design engineering services for the plant, which became operational in just 36 months from notice to proceed using a fixed price design-build delivery method.

"Most people recognize the Carlsbad Desalination Plant as a modern day engineering marvel. But for the businesses and residents of San Diego County, it symbolizes a local, reliable, high-quality water source that doesn’t just deliver in times of drought, but improves quality of life for the long haul."

—John McCarthy, Water Business Line President, North America

Innovative techniques included reusing an existing seawater intake/discharge conduit for connection to the plant and for concentrated brine disposal to limit impacts to the marine environment. Detailed analysis and modeling to prevent concrete corrosion was completed to optimize construction duration and plant reliability. The team also focused on materials of construction for all piping and equipment given the seawater environment.

The project features paving designs that reduce storm runoff, solar reflective roofing materials and fixtures that optimize water efficiency. Built on an existing site along the Pacific coast, the plant takes up 30% less space than similar facilities. Energy-saving technology and sustainability measures implemented during the design-build process have made the Carlsbad Desalination Plant the first carbon neutral infrastructure project in California.

The Carlsbad Desalination Plant is a sustainable solution to San Diego County’s water challenges and provides a model for desalination plants in drought-stricken areas around the United States. By providing a water supply independent of the region’s weather conditions, the plant is improving quality of life for years to come.

The landmark project has been the recipient of numerous awards and accolades for its design and sustainability since going online. In 2017, the American Council of Engineering Companies (ACEC) awarded the Claude “Bud” Lewis Carlsbad Desalination Plant with a Grand Award in the water resources category.



Million gallons of fresh drinking water per day


San Diego County residents served


Less space used than similar facilities

Questions about this project

Peter Tymkiw

Senior Vice President 602 797 4612 Ask me a question
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