Desalination will be key to California’s water future. It needs to improve first

If the climate crisis is coming, the water crisis is already here. 

As rice fields were fallowed in California, Lake Mead water levels almost sunk so low that Hoover Dam could no longer generate power, and life-threatening toxic dust blew off the dried-up Salton Sea. 

Thirty percent of the world population will face water shortages of some kind by 2025. Things are only going to get worse. 

Climate change will cause the Colorado River, which supplies water for 40 million people, irrigates 6 million acres of farmland and underpins a quarter of the nation’s economy, to lose more than half of its flows by 2100. The depletion of the Ogallala Aquifer in the Midwest threatens agriculture so radically that serious proposals have explored a water pipeline from Louisiana. 

Beyond these particular water-strapped cases, of which California has many, warming delivers the one-two punch everywhere, whether it’s from lower water supply due to reduced snowpack and higher evaporation, or increased demand because of 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 just aren’t enough for California.

The water crisis will only be solved if we realize the once quixotic vision of desalination, turning seawater into freshwater. Today, roughly 18,000 desalination plants produce around 1% of the world’s freshwater, with production concentrated in regions of high 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 delivers 50 million gallons of freshwater per day. And just last month, a smaller desalination plant was unanimously approved to deliver freshwater to Orange County.

Desalination also represents a prominent piece of Gov. Gavin Newsom’s State Water Plan. But even state-of-the-art plants still suffer from issues that imperil their ubiquity.

The desalination process is so energy-intensive that desalination plants often require carbon-emitting power plants right next door, which can increase costs up to 10 times higher than groundwater. The high-pressure intake of seawater also threatens ocean life, and the output of brine threatens coastal environments. 

With high energy use, environmental dangers and high costs forced onto ratepayers, desalination faces strong opposition across the political spectrum. But this resistance overlooks both the necessity of desalination – at least relative to more dire options – and the potential promise of improved desalination technologies.

Saudi Arabia recently authorized a massive solar project to fully power an existing plant, showcasing the potential of a carbon-free desalination future. To its credit, the Orange County plant will use slanted wells that draw water from beneath the sea bed to protect ocean life, and the brine will be treated at a nearby wastewater treatment facility. 

Energy recycling, alongside better electronics, are enabling less energy-intensive (and cheaper) methods of desalination, including breakthrough concepts like using shockwaves. 

Desalination will be a major piece of California’s water future, and its inevitability demands the research, policy and funding attention of an imperiled human right. Safe, efficient and clean desalination means fewer dams, cheaper and broader access to water, and the ability to support population growth while continuing to produce food for the country and world. 

The alternative is dry, dusty and deadly.