Once improved, desalination could be a better drought solution for California than water reuse or more sustainable groundwater management.
If the climate crisis is coming, the water crisis is already here.
As California’s rice fields lay fallow, the water level in Lake Mead dropped almost so low that the Hoover Dam could no longer generate electricity, and life-threatening toxic dust blew into the parched Salton Sea.
Thirty percent of the world’s population will face some form of water scarcity by 2025. Things will only get worse.
Climate change will cause the Colorado River, which supplies water to 40 million people, irrigates 6 million acres of farmland and underpins a quarter of the nation’s economy, to lose more than half its flow by 2100. The Midwest threatens agriculture so radically that serious proposals have explored a water supply from Louisiana.
Aside from these particular cases with waterproof straps, of which California has many, warming is everywhere, whether due to lower water supplies due to reduced snowpack and higher evaporation, or increased demand due to higher temperatures.
There is no single way out of a future in which all agriculture leaves the West, desert cities from Denver to San Diego are no longer livable, and Native Americans continue to be denied legally enshrined water rights. Measures like better water reuse and more sustainable groundwater management are simply not enough for California.
The water crisis will only be solved when we realize the once quixotic vision of desalination, turning seawater into fresh water. Today, roughly 18,000 desalination plants produce approximately 1% of the world’s fresh water, with production concentrated in areas with severe water scarcity such as Israel and Australia.
In 2007, San Diego County approved the largest desalination plant in the Western Hemisphere. The Carlsbad Desalination Plant now supplies 50 million gallons of fresh water per day. And just last month, a smaller desalination plant was unanimously approved to supply fresh water to Orange County.
Desalination is also a significant part of Gov. Gavin Newsom’s state water plan. But even the most modern plants still suffer from problems that threaten their ubiquity.
The desalination process is so energy-intensive that desalination plants often require carbon-releasing power plants next door, which can increase costs up to 10 times that of groundwater. High-pressure seawater intake also threatens ocean life, and brine outflow threatens coastal environments.
Due to high energy consumption, environmental hazards and high costs imposed on ratepayers, desalination faces strong opposition across the political spectrum. But this opposition overlooks both the necessity of desalination—at least compared to worse options—and the potential promise of improved desalination technologies.
Saudi Arabia recently approved a massive solar project to fully power an existing plant, showing the potential of a carbon-free desalination future. To its credit, the Orange County plant will use inclined wells that draw water from beneath the seabed to protect ocean life, and the brine will be treated at a nearby wastewater treatment facility.
Energy recycling, along with better electronics, enables less energy-intensive (and cheaper) desalination methods, including breakthrough concepts such as the use of shock waves.
Desalination will be a major part of California’s water future, and its inevitability requires research, policy, and financial attention to the human rights at stake. Safe, efficient and clean desalination means fewer dams, cheaper and wider access to water and the ability to support population growth while continuing to produce food for the country and the world.
The alternative is dry, dusty and deadly.