San Diego


carlsbad desal plant
Aerial view of the Carlsbad Desalination Plant (Source: SDCWA,

The nation’s largest seawater desalination plant opened in Carlsbad, California, ten miles from San Diego. The Claude “Bud” Lewis Carlsbad Desalination Plant is capable of producing 50 million gallons of freshwater per day using reverse osmosis technology. The Plant and 10-mile distribution pipeline was first envisioned in 1998, and after many years of planning and permitting, constructed started in 2012. Construction of the plant was made possible through a public-private partnership between four partners: Poseidon Water, owner and operator; Stonepeak Infrastructure Partners, private equity partner; IDE Technologies, an Israeli-based operations and maintenance company; and the San Diego County Water Authority (SDCWA), the regional wholesaler water system. In 2012, SDCWA and Poseidon Water entered into a 30-year purchase agreement for the Plant’s entire output of 50 million gallons

Water Reuse

Many water and wastewater agencies in the San Diego region have and are expanding recycled water production. Recycled water is considered a crucial part of regional water security as it facilitates the ability to rely less on imported water. The SDCWA estimates that approximately 30,000 acre-feet of recycled water is reused annually, and this figure is expected to grow in coming years. A key part of this growth is that starting in 2023, the City of San Diego’s Pure Water program will be able to provide a third of the city’s needs by 2035 from recycled water.