California Water Experts Prepare for Climate Whiplash

As climate change brings sudden shifts between extreme drought and catastrophic floods, water policy experts urge state resource managers to take a new approach.

California officials regularly tout their global leadership on climate, yet experts warn that state preparations for a warming world need a major overhaul.

The state hit its 2020 goal of mitigating climate change by reducing planet-warming greenhouse gases to 1990 levels six years early. But adapting to chaotic climate disruptions already underway while planning for an uncertain future remains a formidable challenge. 

California’s climate policies are underfunded and “stretching the capacity of local, state and federal agencies responding to the urgent issues of today,” wrote Letitia Grenier, director of the Water Policy Center at the Public Policy Institute of California, or PPIC, in a report released earlier this month.

Global temperatures over the past quarter century are higher than at any time in recorded history and California just saw its hottest July ever. Over the past decade, the state has experienced one of its driest periods, its biggest and most destructive wildfires, record-breaking heat waves and catastrophic flooding, as already stressed ecosystems struggled to cope with land use changes and water diversions.

Climate change has made these extreme events more intense and frequent, challenging policymakers to balance today’s pressing needs with tomorrow’s unknown perils. Of all California’s projected climate threats, policymakers are least prepared for impacts on fragile ecosystems and flood-prone regions, the report authors warn.

Improving infrastructure and emergency response and preparedness will protect lives and livelihoods, but Californians will have to make tough choices about priorities and how to fund them, Grenier warned in the water center’s report, “Priorities for California’s Water: Are We Ready for Climate Change?” 

The report describes the many ways a hotter world has already affected and is likely to further stress the state’s water supply. It’s “uncharacteristically long” because there are so many priorities that need attention, said PPIC Water Policy Center senior fellow and coauthor Jeff Mount earlier this month at the center’s annual water conference in Sacramento. 

Those priorities include making sure communities, farms and ecosystems receive sufficient high-quality water, protecting the headwater forests that replenish water supplies and managing flood and wildfire threats, all as a volatile climate brings unknown risks. 

The center provided a “really excellent summary” of the ways climate is affecting water issues, said Felicia Marcus, a visiting fellow at Stanford University’s Water in the West Program who was not involved in the report. “I’m really grateful for it.”

Too often in the California water world, people pick a narrow issue and just promote their comfortable talking points, said Marcus, who served as chair of the California Water Resources Control Board under Gov. Jerry Brown and as EPA Region 9 administrator under the Clinton administration. “This is an incredibly useful guide to all the different ways climate is going to affect a lot of things with some ideas about what to do about it in a way that’s accessible.”

Scientists predict that annual precipitation will be concentrated in less frequent, more powerful storms like those carried by atmospheric rivers, which can cause catastrophic flooding. Warmer winters are shifting precipitation from snow to rain, which also raises flood risk while reducing the storage capacity of snow in the mountains. The Sierra Nevada snowpack, which has historically accounted for nearly a third of the state’s water supply, will likely drop by 55 percent by midcentury and by 80 percent as 2100 approaches, models suggest. Sea level along California’s coast is expected to rise by more than 6 feet by the end of the century. 

The state is also likely to see more very dry years and more multi-decade droughts. As a warmer atmosphere absorbs more moisture, soils dry out and, when it does rain, less water reaches streams and rivers, leaving less to irrigate farms, recharge depleted aquifers and revive long-suffering freshwater ecosystems. 

Efforts to prepare for all these extreme events will be further hampered by climate whiplash, dramatic swings between prolonged dry spells and intense wet periods.

On the bright side, no one in California is arguing about whether the climate is rapidly changing, Mount said. “We are literally just arguing about the solutions and how to fund them.”

“Are We Doing This Right?”

When the PPIC team sat down to write the report last spring, Mount told Inside Climate News, they looked at the seemingly constant stream of water policies coming out of the governor’s office and asked, “Are we doing this right? And the answer was the classic, yes, no, maybe.”

The team noticed a problem with the way individuals, agencies and organizations manage water, whether for ecosystems, hazards or human supplies. Managers typically had a long list of things they wanted to do right away, based on a specific date and condition, that usually required a lot of money. For example, Mount said, managers looking at coastal flood risk hazards often say, “Let’s build for 2050, a date certain, and one foot sea level rise, a condition certain.”

Then they scope out the costs, “freak out” about how expensive it will be, get paralyzed and ditch the project, he said.

That’s what happened with a plan to prepare for severe drought by expanding Los Vaqueros Reservoir in the San Francisco Bay Area. The local water district spent $120 million on the initial phase of the expansion. But after estimated costs for the next phase approached $1.6 billion, and new rules to protect endangered fish cut water allocations, managers deemed the project unviable.

“I’m still in a state of shock over the collapse of Los Vaqueros,” Mount said. 

A few years ago, Mount and his colleagues reviewed projects funded through a $2.7 billion measure to invest in new water storage projects. Of all the projects, Los Vaqueros “was the slam dunk,” he said. “It made environmental sense. It made economic sense. It made sense looking to the future.”

California has to do a much better job of capturing water during wet periods in order to get through the dry periods, Mount said. “Los Vaqueros did that really well.”

Sticker shock, the PPIC team realized, inevitably derails even the best-designed projects. 

“We did these massive infrastructure investments in the 20th century,” Mount said, pointing to the State Water Project, a giant network of dams and aqueducts that ferries rain and snowmelt from the Sierra Nevada to farms and cities, and the sprawling series of levees and bypasses that make up the Central Valley flood control system. “But somehow, when we got to the 21st century, we lost our will to plan for the long range, a distant future.”

Everyone’s focused on the money spent today rather than the broader benefits gained over time, he said. “And when it comes to climate change, you couldn’t have a worse outcome.”

That’s why the center is promoting an “adaptation pathways” approach for water along the lines that California adopted as part of its climate resiliency plan. Under this approach, managers adopt flexible, modular plans that stagger investments, knowing they may need to adjust as conditions change, Mount said. And if plans need to be abandoned, it’s not due to sticker shock but to accommodate new conditions.

As someone who’s worked on water issues for years, Marcus appreciates the way the team framed the issues to help people rethink the old ways of projecting what’s going to happen on a specific time horizon and then planning for it. “With climate change, that’s out the window,” she said, because it wreaks havoc on the earth’s systems in increasingly unpredictable ways.

“The question for us,” Marcus said, “is how do you come up with plans that give us the best glide path for the next 20 or 30 years, or whatever the life of the investment is?”

Then when predictions about conditions crumble along with an Antarctic ice shelf and force managers to diverge from their plan, she said, they’re going to have decades of technological and scientific development that will offer different options.

A Few Bright Spots

In addition to all the water challenges in California’s future, the report noted some progress. The state’s mandatory water conservation rules have cut urban waste and use. And the Safer Drinking Water Program is working to help the hundreds of thousands of residents with contaminated drinking water systems access clean, affordable drinking water.

Mount, affectionately known as Dr. Doom, said it’s important to celebrate the gains as water experts grapple with “some real difficult work ahead.”

Agricultural users face perennial water shortages, exacerbated by droughts, and a future of reduced flows from California’s rivers designed to replenish parched freshwater ecosystems. Growers long turned to groundwater to irrigate their crops, but decades of unfettered pumping seriously depleted 21 groundwater basins, most in the Central Valley, leaving wells dry and land sinking nearly an inch a year. 

The Sustainable Groundwater Management Act requires managers of overdrafted basins to reach sustainability by 2040, which means the farms in the southern valley could face water cutbacks of nearly 17 percent by then if they don’t come up with new supplies. If cutbacks reach 20 percent, with precipitation shifts and new environmental flow restrictions, the PPIC team cautioned, growers may have to fallow more than 900,000 acres of irrigated farmland.

Groundwater sustainability plans do account for some climate change factors, “but there are two miracles that are going to occur,” Mount said wryly. “Somehow, everything’s going to be solved in 2040 and everything will be fine after that.”

They also need to rethink how they manage forests for a warmer world, the team argues. California’s headwater forests evolved with frequent fires but policies over the past century, which allowed harvesting of the largest trees, snuffed almost all natural wildfires and prohibited cultural burning by Indigenous tribes, led to unprecedented levels of high-severity fires that are devastating these ecosystems.

Multiple measures can boost resilience, including expanding the use of managed fires and restoring meadows and forests. But ensuring headwater forests continue to provide clean, reliable water supplies and reduce wildlife risks as conditions change, the team warned, will require tailoring solutions to the state’s ecologically diverse regions—and teaching Californians how to live with the wildfires that shaped the landscape for millennia. 

Room for the River

California needs a “major overhaul” of policies managing flood risk and freshwater ecosystems to prepare for climate change, the PPIC team warned.

Eighty percent of California’s freshwater fish populations have already declined. More than half of native freshwater species could vanish by century’s end.

The situation for salmon in the Sacramento River is dire, Mount said, and requires a major rethink that integrates climate to reverse their decline. 

Still, it’s not too late to restore native biodiversity and ecosystem health, Mount and his colleagues say—if managers act quickly. They must also start treating ecosystem health as a priority, rather than a constraint, recognizing that a thriving, functional watershed brings benefits to everyone, not just fish.

Stanford’s Marcus sees that framing as absolutely critical, because most dialogue centers around “how much water do we have to give to fish” and take away from cities and farmers. “That is not right. The truth of the matter is, we’re not leaving enough in the environment,” she said. “It always gets the short end of the stick.”

To illustrate how climate change is increasing flood risk, the report used as a benchmark the megaflood of 1861-1862, which dumped 35 inches of rain on Southern California in a month, inundated the Central Valley and left 4,000 people dead. Today, the same type of flood, which is increasingly likely, would likely cost more than a trillion in damages and thousands of lives.

“We are ignoring climate change when it comes to flood management,” Mount said at the conference. “Every policy tool that we have in place to manage floods is built upon the hydrology of the past, not the future.”

Tens of millions of Californians are at a very high risk of a flood at the same time, he said, and climate models predict the likelihood of large floods here is increasing substantially. “This is an out of sight, out of mind problem that is going to bite us.”

During a panel following his talk, Karla Nemeth, director of California Department of Water Resources, assured Mount that flood risk is very much on her mind. “I spend an insane amount of time thinking about flood risk. It’s one of the things that absolutely keeps me up at night,” she said.

“Our poor state climatologist gets a lot of texts from me on a Saturday,” she said. She recently asked him what the conditions that caused last month’s disastrous floods in Valencia, Spain, which killed more than 200 people, might look like in California. 

“This is 120 hours of an atmospheric river with a freezing elevation of 11,000 feet,” he told her. That translates to the volume of precipitation that California would see with back-to-back atmospheric rivers like those that are increasingly dousing California—including right now—and caused the deadly 1997 floods that engulfed towns from Sonoma to Yosemite and cost billions in damages.

The old notions of 100-year floods, which have a 1 percent chance of happening in any given year, are totally meaningless under climate change, Mount said. “We’re trying to build our entire flood control infrastructure based on an erroneous assumption.”

California should learn from the Dutch, who have come full circle from shackling rivers in levees to giving them space, Mount said. “That gives multiple benefits right off the bat.”

Giving room to the river reduces the elevation of floods, feeds wetlands, increases water quality and helps water storage by recharging depleted aquifers. 

To the extent that managers can harness nature-based solutions with multiple benefits, Marcus said, “we’re going to be in better shape.” That way, engineers don’t have to figure out how high a levee wall needs to be forever, or build bigger and bigger walls that ultimately prove useless as sea level rises. Instead, she said, they can integrate wetlands into flood management, helping them migrate uphill as sea level rises, as managers plan to do by building terraced wetlands around San Francisco Bay.

Climate change impacts are here now, said PPIC’s Grenier, referring to the hurricane that devastated western North Carolina and California megafires that destroyed entire towns as wake-up calls. “And they’re going to accelerate, so our preparation has to accelerate with them.”

California voters recently approved a $10 billion bond to support climate resilience projects. But that’s a drop in the bucket for the magnitude of the work that needs to be done, Mount said. 

He understands how hard it is to invest and plan for low probability, high consequence events like mega floods and fires. But they’re becoming more common under climate change. That’s why he’s taken to talking about the Clint Eastwood school of risk management. You have to ask yourself one question, he says, doing his best Dirty Harry impression: “Do you feel lucky?”

Cover photo: Firefighters block off a flooded road as a powerful atmospheric river brings heavy rains and wind to the San Francisco Bay Area on Nov. 22 in Windsor, Calif. Credit: Justin Sullivan/Getty Images