San Diego – Desalination

The nation’s largest coastal desalination plant opened in 2015 and is located in Carlsbad, California, ten miles from San Diego. The Carlsbad plant is capable of producing 50 million gallons per day (56,000 acre-feet per year) of freshwater using reverse osmosis technology. 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 SDCWA, the water purchaser.

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