Over and over again, drought launches California into a familiar scramble to provide enough water.

Cities and towns call for conservation and brace for shortages. Growers fallow fields and ranchers sell cows. And thousands of people discover that they can’t squeeze another drop from their wells.

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?

The Newsom administration unveiled a roadmap for bolstering the state water supply. But the plan — which has few details, distant deadlines and scant plans for agriculture — has been met with criticism

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.

Recycle more water

Turning sewage into water is the Golden State equivalent of turning water into wine, and California has been doing it for decades.

Californians used about 732,000 acre feet of recycled water 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.

None of it flows directly from “toilet to tap.” But the State Water Resources Control Board is developing regulations for direct potable reuse of highly treated wastewater.

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 with recycled wastewater since the 1960s.  

Newsom called for ramping up recycled water use by 2030 by roughly 9% from the amount used in 2021, rising to 1.8 million acre feet by 2040. Critics, however, voiced disappointment with the target’s lack of ambition which falls short of previous state goals

In the meantime, water suppliers are spending big to build out water recycling facilities in Northern and Southern California.  

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.

More desalination

Pipes containing drinking water at the Poseidon Water desalination plant in Carlsbad on June 22, 2021. Photo by Mike Blake, Reuters
Pipelines at the Poseidon water desalination plant in Carlsbad. Photo by Mike Blake, Reuters

Desalination is an oft-touted fix for water woes in California, with its ample shoreline. But in practice, environmental concerns and costs have limited the energy-intensive practice

Four ocean water desalination facilities in California produce nearly 60,000 acre-feet of drinking water. More provide water for industries or other facilities

New desalination proposals have been rife with controversy. The California Coastal Commission in 2022 rejected a seawater desalination plant in Huntington Beach, with state analysts warning of high costs, a lack of local demand and risks to marine life. But just months later, the commission pivoted, greenlighting a plant in Orange County’s Dana Point.

A lesser-known but rapidly growing strategy is brackish water desalination, which cleans up salty supplies, such as from groundwater, that can then be used for drinking water. 

About 23 of these plants have the capacity to produce nearly 140,000 acre-feet of water in a year, based on a 2013 analysis. They use less energy than their seawater counterparts. 

Capture stormwater runoff

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 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.

Some local agencies have been corralling stormwater to replenish aquifers for years, with dozens more projects in the works

The Fresno Metropolitan Flood Control District, for instance, captures runoff across 400 square miles in Fresno County. The water is used to fill more than 150 ponds, where it trickles through the soil to refill groundwater stores. In bone-dry 2021, storm flows accounted for almost all of the district’s groundwater recharge.  

Santa Monica has been a leader in treating urban runoff, and plans to upgrade a recycling facility built near its famous pier more than 20 years ago. The plan is to treat the collected runoff and stormwater so it’s clean enough to be injected directly into Santa Monica’s groundwater basin. 

Strategies for using stormwater 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.

But barriers remain to capturing more of the flows. These include high costs and a lack of funding, concerns about impacts to water quality, and lengthy planning and approval processes.

Transform California agriculture

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

How much water is used by farms changes with the weather from year to year. But it remained generally flat between the 1980s and 2015. 

“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.

Almonds and pistachios are the fourth most water-intensive crops in California, after rice, alfalfa and irrigated pasture, according to the Pacific Institute. Nut acreage has soared in the past 10 years, but what that means for water is less clear: State data lags and there’s no real-time monitoring of agricultural water use.

More changes are coming, with climate change parching crops and state law calling for sustainable groundwater management. Complying with California’s Sustainable Groundwater Management Act could require 500,000 to 1 million acres of prime agricultural land to come out of production in the San Joaquin Valley, according to The Public Policy Institute of California.  

The state has earmarked $110 million over three years to repurpose agricultural land and put it towards other uses, such as groundwater recharge and habitat restoration. Other funding is provided to growers who fallow their fields.

Growers also could opt for crops grown during the rainy season and breed more drought-tolerant varieties. And leaving crop residues in fields and reducing tillage can allow soil to retain more water.  

More efficient irrigation systems help, too. But the Farm Bureau’s Merkley said making water go farther 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.

Tear out lawns

About half of water used in cities and towns is used outdoors for washing cars, hosing down sidewalks and irrigating roughly 4 million acres of turf. Turf drinks up the most water in any month, in any part of California, of any plant analyzed in a state report.

Tearing out turf and replacing it with more drought-tolerant plants could save between 1 million and 1.5 million acre-feet per year, with the largest savings coming from residences, the Pacific Institute estimates.  

California temporarily banned watering decorative, non-functional turf at businesses and institutions under emergency regulations adopted in May 2022, and is reviving rebates for tearing out turf.

A statewide turf replacement program that began during the last drought tapped out in June 2020 after putting more than $20.5 million towards helping people replace their lawns. Local water providers continued their own multi-million dollar efforts, however, and the state put $75 million in funding toward rebates in the state’s 2022-2023 budget. 

The Metropolitan Water District has spent more than $350 million coaxing Southern Californians to convert more than 200 million square feet of turf. And there is a ripple effect, with some of their neighbors tearing out their lawns, too. 

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%.

Replumb California

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. 

But the state’s environmental review has raised serious concerns that the tunnel project could harm endangered salmon and other species. And, if eventually approved, it would take decades to complete and cost billions of dollars.

In the meantime, California’s existing networks of pipes, aqueducts and canals lose precious supplies to leaks and evaporation. Some strategies have emerged to reduce these losses, including lining canalswhich can also impede groundwater recharge — or covering them with solar panels

In cities and towns, water suppliers lose roughly 316,000 acre-feet of water 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. 

Store more water in reservoirs

Reservoirs aren’t the field of dreams: Even when we build them, the water doesn’t necessarily come. Statewide reservoir storage plunged to 69% percent below average by the end of September 2022, on the heels of the state’s driest three-year stretch on record

Proposition 1, approved in 2014, set aside $2.7 billion to fund water storage projects. The three projects eligible to receive funding, which include the controversial Sites reservoir, would increase storage capacity by more than 1.75 million acre-feet, enough to supply more than 6 million households. 

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 warned in 2018 

Many reservoirs in California do double duty as flood control which means that space for potential floods must be maintained even in dry years

But state, federal and local water managers are working with scientists on strategies to reduce flood risk while reserving more water in California’s reservoirs.
Water managers at Lake Mendocino, for instance, are incorporating new weather forecasting tools to update decades-old guidelines governing when to hold onto water and when to release it. The strategy increased the lake’s storage by nearly 20% in 2020, with most of the water going to agriculture.

Recharge groundwater basins

Source: California Department of Water Resources

California’s underground aquifers can hold vastly more water than its reservoirs — between 850 million and 1.3 billion acre-feet of capacity below ground, compared to about 38.1 million acre feet above ground, according to the Department of Water Resources. 

Local districts have been carefully tending groundwater for decades. The Orange County Water District, for instance, pumps highly treated water underground to keep seawater at bay and replenish local drinking water stores. In the Southern San Joaquin Valley, water suppliers funnel surface water into underground storage at the controversial Kern Water Bank, largely for agricultural irrigation.

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. 

Unless that bottleneck is widened, plans to end the overdraft of depleted aquifers in the San Joaquin Valley are calling for more groundwater recharge than is likely realistic, according to the Public Policy Institute of California.

Control greenhouse gases

Climate change is worsening droughts and is expected to fuel even more extreme swings from dry to deluge. The Newsom administration warns that climate change could deplete state water supplies by up to 10% by 2040

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. 

“Much larger reductions are needed to reach the ambitious 2030 target — an additional 40 percent reduction below the original 2020 limit,” Air Resources Board Chair Liane Randolph said in July, 2021. 

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.

Reform water rights

Illustration by Miguel Gutierrez Jr., CalMatters; iStock
Illustration by Miguel Gutierrez Jr., CalMatters; iStock

California’s water supplies are governed by an arcane and complex rights system based on the Gold Rush-era philosophy of “first in time, first in right.” Generally, those with the oldest claims are the last to be cut back during shortages. 

Environmental justice advocates and legal experts point out that this system of seniority is plagued with inequalities and based on a history of violence and systematic exclusion of Native peoples and people of color. Legislative analysts also warned more than a decade ago that, in some cases, water rights are “oversubscribed,” meaning they allocate more water than is available.

The latest drought prompted California officials to periodically curtail water rights across the state as supplies dwindled. But a scuffle in the Shasta Valley, when some ranchers temporarily refused to comply, revealed that the state’s enforcement muscle is slow to flex and hamstrung by restrictions on penalties. 

Water law experts have been pushing for changes. Recommendations include increasing funding to help Tribes and other underrepresented groups participate in state water proceedings, and granting state water regulators more authority to act swiftly when people violate curtailment orders. 

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.” 

More cloud seeding and solar panels

Clouds gather as above a ridge in Mountain View on Jan. 7, 2016. Photo by Noah Berger, Reuters
Clouds gather above a ridge in Mountain View. Photo by Noah Berger, Reuters

A couple strategies sound like science fiction, but they are already being used and hold some promise.

Santa Barbara County has been practicing cloud seeding for decades — releasing tiny particles of silver iodide into the atmosphere during certain storms to coax water vapor into forming ice crystals and falling to earth. Researchers say it’s difficult to evaluate how well it works, partly because precipitation is so variable, but one analysis pointed to increased precipitation of 9% to 21% in two target areas. 

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 percent.

One Central Valley town has turned to another unusual strategy: solar-powered “hydropanels” that draw water vapor from the air. In Allensworth, a historic Black town, hydropanels are expected to produce enough water to fill nearly 44,000 bottles over their lifetime — although not enough to replace the town’s contaminated groundwater.

These panels have been used around the world in places that lack clean water, including a Navajo reservation in Arizona, Australia, India and Kenya. Actor Robert Downey even included them when he built his eco-friendly house in Malibu.

Pipe dreams: Pipelines to the Midwest and towing icebergs

Illustration by Miguel Gutierrez Jr., CalMatters; iStock
Illustration by Miguel Gutierrez Jr., CalMatters; iStock

Some strategies are as outlandish as they sound. Actors and political candidates alike 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 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, 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. 

Even California lawmakers have eyed icier reaches of the world for new water supplies: In 1978, the Legislature passed a resolution calling for federal support of a pilot program to tow icebergs from Antarctica. 

Illustration by Miguel Gutierrez Jr., CalMatters; iStock
A resolution approved by the California Legislature in 1978. lllustration by Miguel Gutierrez Jr., CalMatters; iStock

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: 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.

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Rachel Becker covers California’s complex water challenges and water policy issues for CalMatters. In 2021 she won first place for Outstanding Beat Reporting from the Society of Environmental Journalists,...