Editor’s Note: This is the second in a three-part series on the development of seawater desalination plants in California and other drought-prone regions, looking at the environmental and economic challenges involved.
Water has been called the lifeblood of the American West. Nowhere is this more true than in California, where dwindling water resources and a swelling population are pushing water agencies, businesses and nonprofits to find new ways to slake the state’s growing thirst. Some say the state only needs to look west to the Pacific Ocean for a partial solution to its problem.
About 20 seawater desalination plants are in various stages of planning and development along the coast.
“It’s kind of like the Gold Rush,” said Paul Choules, vice president for desalination and reuse for Veolia Water Solutions and Technologies, one of the world’s biggest desalination companies, of the potential desalination market in California. “Unfortunately, there’s no gold there yet.”
And it’s unlikely that desalination alone will be the silver bullet that eliminates the state’s water woes. Long timelines, high price tags, complex permitting and environmental challenges mean it could be a long time before most of those plants start producing fresh water — if they ever do. Meanwhile, some water experts say measures such as conservation and water reuse could meet the state’s future water needs.
California’s Water Constraints
“The question, yet to be answered, is, ‘Is there truly a need for desalination in California?” Choules said. “How much water is available?”
California has been called the most hydrologically altered landmass on the planet. Water and its storage, management and transport has been essential to the state’s evolution into one the world’s largest economies, the country’s most populous state and its biggest agricultural producer.
That’s largely because the bulk of the state’s water supplies are far from the areas of high demand.
In California, population and agricultural production are weighted toward the southern and central portions of the state, while most precipitation falls in the north. Addressing this imbalance requires transporting water over long distances, a costly and energy-intensive undertaking.
In recent years, water supplies from the Sacramento-San Joaquin Delta, which provides water to more than two-thirds of the state’s population, have been reduced due to adverse impacts on wildlife populations, like the endangered delta smelt. California has also been ordered to reduce the amount of water it draws from the taxed Colorado River.
“California doesn’t have a lot of natural renewable water resources,” said Lisa Henthorne, director of the International Desalination Association, a nonprofit group based in Topsfield, Massachuestts. Those that it does have are subject to fluctuating allocations and water rights, and subsequent disputes between various interests.
Water constraints are only likely to increase in the face of climate change. Warmer temperatures are expected to reduce the snowpack that acts a natural reservoir for the state’s water supply, exacerbate extreme weather events, and change runoff patterns, in the face of increased water demand.
Studies show that rising temperatures could mean that up to one-third of the state’s precipitation that occurs as snow could instead fall as rain, causing heavy runoff and flooding, according to the Association of California Water Agencies.
Meanwhile, a booming population will only add to the state’s thirst. By 2050, California’s population is expected to increase by about 70 percent over its population in 2000, according to the state’s Department of Finance, with a projected population of 60 million.
Desalination Won’t Come Cheap
Despite the bleak picture of California’s water future, and the clear fact that the state will have to find other ways to meet its water needs, desalination will likely only be part of the solution, observers say.
That’s partly because desalinated seawater doesn’t come cheap. Desalination offers a water source that is free from the climate-sensitive fluctuations that plague other water supplies. But as an energy-intensive water source, its cost is closely tied to changing energy prices, according to the Pacific Institute, an Oakland, Calif.-based research group that focuses on water issues.
Estimates peg the cost of producing desalinated water at $1 per cubic meter or more. Urban water users, by comparison, typically pay between 26 cents and 75 cents per cubic meter. An increase in energy costs of 25 percent could raise the costs of desalinated water by up to 15 percent.
If all the proposed plants in California get built, they would produce tens of millions of gallons of water daily but only meet about 6 percent of the state’s entire water needs.
“There’s not one solution,” said Heather Cooley, a senior research associate at the Pacific Institute. “We need to take a look at all the options available” to bolster the state’s water supplies, she added, including water conservation and efficiency, recycled water and rainwater harvesting.
The institute estimates that one-third of California’s urban water use can be saved with existing technologies, at below the cost of tapping into new water resources.