Persistent drought conditions in California have caused a recent surge of interest in ocean desalination as a source of fresh water for drinking, irrigation, and other uses. There are currently nineteen ocean desalination facilities being considered in California, in addition to the largest operating facility in the Western Hemisphere located in San Diego, and another facility of the same size close to starting construction in Orange County. While drawing water from the ocean may seem like a promising solution, it is in fact the most expensive and energy intensive option available, and should be an absolute last resort. California has only begun to tap the potential for conservation and water recycling, and these more sustainable and affordable water sources should be our priorities.
Desalination facilities cause significant harm to marine life. Facilities using open ocean intakes pull in millions of gallons of seawater a day, killing billions of fish, fish larvae, and other animals each year as they are forced up against screens or sucked into facilities’ filtration systems. Additionally, the discharge of highly concentrated “brine” into the ocean can be toxic to kelp beds and marine life, even at low concentrations.
Additionally, desalinating water uses more energy, per gallon of water, than any other source. Desalination plants connected to the electric grid increase electricity consumption from fossil fuel plants, increasing GHG emissions and undermining California’s efforts to mitigate climate change and clean up our air and water. Finally, water produced by ocean desalination is very expensive, with an average price per acre-foot that is four to eight times higher than water from other sources.