A celery field is sprayed by irrigation equipment in the Salinas Valley. California's agriculture is the most productive in the country, but it also drinks up about 80% of the developed water used in the state. (Pgiam/Getty Images)
Over and over again, drought launches California into a familiar scramble to provide enough water.
So where can California get enough water to survive the latest dry stretch — and the next one, and the next?
Can it pump more water from the salty Pacific Ocean? Treat waste flushed down toilets and washed down drains? Capture runoff that flows off streets into storm drains? Tow Antarctic icebergs to Los Angeles?
Every time another drought rolls around, an array of suggestions rise to the surface. We take a look at the strategies that could work — along with the more outlandish ones — and the obstacles they face.
Californians used about 732,000 acre-feet of recycled water (PDF) in 2021. That’s almost two-thirds of the water that the state’s major aqueduct funneled south in dry 2021 — equivalent to the amount used by roughly 2.6 million households.
For now, much of California’s recycled water is used for non-drinking purposes, like irrigating landscapes, golf courses and crops. It also refills underground stores that provide drinking water. Southern California has been replenishing local groundwater supplies (PDF) with recycled wastewater since the 1960s.
But there’s a catch: As Californians replace their water-guzzling household appliances with more thrifty devices and let the yellow mellow before flushing, the waste stream becomes more concentrated — which could lead to higher treatment costs, more contaminants and less recycled water overall.
The rainwater and spillover from sprinklers that flows off roads, yards and rooftops — much of it eventually emptying into waterways or the ocean — could help boost California’s water supply.
The state's urban areas shed 770,000 to 3.9 million acre-feet of runoff a year that could be captured, according to the Pacific Institute. That’s enough to supply between 2.7 million and 13.7 million households for a year.
The potential is highest in Southern California, which has lots of pavement that sends rainwater and irrigation runoff into storm drains. Collecting this runoff and feeding it into aquifers — or eventually treating it and sending it to taps — would avoid wasting it.
Strategies for using stormwater (PDF) also include installing permeable pavement in yards and communities and building basins that let it drain into the soil instead of flowing into storm drains or streets.
“The only real way to reduce water use further in agriculture is to grow less food and farm products, or take more agricultural land out of production,” said Danny Merkley, water resources director with the California Farm Bureau Federation.
More efficient irrigation systems help, too. But the Farm Bureau’s Merkley said making water go further is growing more difficult and smaller growers can struggle to pay for it. Also, an international team of researchers warned that increased efficiency must be accompanied by robust monitoring and caps on water extractions. Otherwise, they wrote, it can backfire by prompting planting of more acreage with more water-intensive crops.
California temporarily banned watering decorative, non-functional turf at businesses and institutions under emergency regulations adopted in May 2022 (PDF), and is reviving rebates for tearing out turf.
But there are limits to peer pressure. Celebrities and others continue to be called out for over-watering their yards, and urban water use remains high, with cities and towns, particularly in Southern California, failing to meet Newsom’s goal to cut their water use by 15%.
A controversial plan to replumb the California Delta — decades in the making — would funnel water from new intakes north of the delta as well as existing south Delta pumps, sending hundreds of thousands more acre-feet of water south instead of allowing it to flow out to the ocean.
In cities and towns, water suppliers lose roughly 316,000 acre-feet of water (PDF) every year through leaks in their vast mazes of pipes. The state set new standards requiring water providers to meet loss targets starting in 2028, which could save about 88,000 acre-feet a year.
How much they would increase the water supply available each year, however, is unclear. Lengthy droughts deplete reservoir storage, and "the average volume of new water from these facilities is small, and costs are high," the Public Policy Institute of California (PDF) warned in 2018.
The Newsom administration has called for increasing groundwater recharge yearly by at least 500,000 acre-feet. But ongoing challenges remain to widespread groundwater recharge.
“There’s a lot more empty aquifers than there are unclaimed sources of water in California,” said Michael Kiparsky, Water Program Director at the Center for Law, Energy & the Environment at UC Berkeley School of Law.
It’s not just about the amount of water, Kiparsky said, it’s also about the logistics. California will need to ensure there’s enough capacity to quickly move flood flows to the right basins for recharge during California’s brief rainy season.
Curbing use of fossil fuels globally can blunt some of the severity of future droughts, researchers reported. But even California, which prides itself on its green image, will need to pick up the pace to meet state goals for cutting greenhouse gases.
California’s clean air regulators are ramping up their efforts in the state’s updated climate roadmap. But parts of the plan, including its reliance on technologies to remove carbon dioxide from the atmosphere or capture it from smokestacks, remain contentious.
A water board spokesperson said that they are developing pilot projects to collect real-time data about water diversions, and are considering “adopting regulations that would allow for curtailments of water rights in years when there is not a declared drought emergency.”
The Desert Research Institute has led this effort, seeding clouds in California’s San Joaquin Valley, Nevada, Wyoming, Montana, Colorado and Australia. In Wyoming, its 10-year experiment in mountain regions increased snowpack from winter storms by 5% to 15%.
Some strategies are as outlandish as they sound. Actors and political candidates alike (PDF) have proposed piping water from wetter places, like the Mississippi River. Some have talked for decades about tapping into the Great Lakes.
California has a long, storied history of moving water — some say stealing — from one place to another within the state. It’s even inspired at least one movie.
“If history has taught us anything,” Idaho state Sen. Brian Donesley, a former Angeleno, told the Los Angeles Times, “it is that when Californians get thirsty, they will use cash, the law, raw political power and, if necessary, the point of a gun barrel to satisfy their thirst.”
But nowadays there are many legal and logistical roadblocks that would stop California from taking water from Alaska, the Midwest or Canada. For one, other regions would be unlikely to allow it. Diverting large volumes of water from the Great Lakes, for instance, is prohibited without the approval of all eight states in the U.S. and two provinces in Canada under a compact signed into law by President George W. Bush.
Pipe dreams of pipelines have been floated often enough that the U.S. Bureau of Reclamation evaluated them (PDF), reporting that a pipeline to the Mississippi River, for instance, would cost billions, use up a lot of energy to pump the water, require decades of construction and face a quagmire of legal and policy issues.
Towing icebergs and filling up tankers with freshwater from Alaska drew mentions from the U.S. Bureau of Reclamation, as well as this diplomatic verdict (PDF): These ideas “have either significant technical feasibility challenges or significant questions regarding their reliability.”
A small iceberg, for instance, would contain only 250 to 850 acre-feet of water and would require new port terminals, pipelines and pumps to transport the melted ice to a reservoir. The process would take “at least 20 years.”
As for tankers, even the largest would hold only about 80 million gallons — barely a drop in the bucket for California.
Still, the ideas endure. At a press conference in summer 2022, Newsom fielded a question about whether pipelines and tankers taking water from faraway places might be the quickest ways to get more water to California.
“What you're talking about are break-the-glass scenarios,” Newsom answered. ”And I assure you, we have some more novel ones than the one you even approached and that are more interesting. But that's for later.”
We’re still waiting.
Stay in touch. Sign up for our daily newsletter.