Ground Rules

When we talk about California's water supply, most people think of the interconnected network of rivers, reservoirs, and aqueducts that cross the state. But, in reality, according to the California State Water Resources Control Board, forty percent of the state's agricultural and residential water is pumped from underground, a figure that jumps to sixty percent during dry years. Ongoing drought has accelerated groundwater depletion at an alarming rate. In fact, a recent NASA study using remote-sensing technology shows that California's groundwater is being drawn down five times faster than fifty-year historical averages. Experts warn that there is a real possibility of complete exhaustion of the state's groundwater if current conditions persist.

In response to this crisis, California lawmakers passed the Sustainable Groundwater Management Act (SGMA) in 2014, a package of bills that require local and regional authorities to actively regulate groundwater use and create sustainable management of groundwater by 2042. “Prior to that, we had no systematic management of groundwater at all,” says Kristin Dobbin, an assistant professor of Cooperative Extension in the Department of Environmental Science, Policy, and Management, noting that “we were the last state in the West to enact a management plan.” 

Though it’s a statewide framework, SGMA is based on the premise that the best solutions will be accomplished locally. Under the plan, groundwater basins designated as medium or high priority were required to form groundwater sustainability agencies (GSAs). These local agencies, in turn, were required to create groundwater sustainability plans. Those “roadmaps to sustainability,” as Dobbin calls them, were due between 2020-2022, and most are now under review by the California Department of Water Resources. Even as they wait for acceptance or revision suggestions, GSAs are mandated to begin enacting their plans. The final—and most difficult piece of the puzzle—will be actually achieving sustainability and other environmental goals over the next twenty years.

A big part of the reason why groundwater supplies in California are so tenuous comes down to their relationship to property rights. “If you own a parcel of land in California, you have the right to use the groundwater underneath that land,” explains Ellen Bruno, an assistant professor of Cooperative Extension in the Department of Agricultural and Resource Economics. “You’ll pay the cost to drill the well and the energy costs to extract it from below, but that’s it.” 

Unfortunately, underground water networks are an unmetered, unregulated, and unmonitored asset that don’t correspond neatly with aboveground property lines or political boundaries. This leads to a classic economic problem—a “tragedy of the commons”—created when the water that one farmer pulls by drilling straight down reduces the supply for everyone. And water pumped today won’t replenish fast enough to be available in a warmer, drier future. “It’s a free-for-all,” Bruno says. “What incentive do you have to constrain your own behavior if your neighbor won’t?”

Broadly speaking, there are only two ways for the state to transition toward sustainability and ensure adequate groundwater for future use: reduce demand or increase supply. Recharging groundwater is difficult. Techniques to capture, save, and later infiltrate water back into the ground do exist, but these solutions are costly and often logistically difficult given existing land uses. And even in a season of heavy rains like California saw earlier this year, tens of billions of gallons are "wasted" out into the ocean.

Most experts believe the lion’s share of the groundwater solution will be on the demand side. SGMA, however, is not a prescriptive management plan filled with detailed rules, so each community is left to determine how to achieve sustainability. According to Bruno, there is a lot of heterogeneity across the state in what approach local agencies are taking, but most are considering reducing demand by either limiting pumping or imposing taxes that will make groundwater more costly.

Both those actions will make farming more expensive, she says. Predicting farmer behavior is as essential as understanding the drought tolerance of one crop versus another. Bruno’s cooperative extension research, through conversations with farmers and local agencies, is evaluating the impact of certain policies on agricultural water use. “We’re assessing how farmers might react if we increase water prices, or if we cap the amount of groundwater that can be pumped in a region,” she says. “And we’re researching potential benefits of allowing farmers to trade their rights to pump groundwater.”

Bruno’s work is critical for informing managers of irrigation districts and hydrologists and consultants at the Department of Water Resources as they consider how to price groundwater usage. “Providing empirical evidence on the price responsiveness of farmers will help inform their management plans,” she says, potentially mitigating the amount of land that needs to be fallowed and the negative effects on farmers and consumers.

In June 2021, the Tulare County town of Teviston—whose 1,185 residents rely on two wells—ran out of water. Their trouble began in 2017, when one well began delivering water that was brown and sludgy. Then their only remaining pump sputtered to a halt as sand choked the machinery. While there is never a good time for a community to run dry, this was a particularly inopportune moment: temperatures topped 112 degrees and most of the residents relied on swamp coolers—which need a constant supply of water—to escape the heat. But even when both wells were working, the water they pumped was contaminated with 1,2,3-Trichloropropane, a carcinogenic pesticide residue.

Numerous groundwater-reliant communities like Teviston stand to benefit from SGMA’s new regulations. “Rural drinking water users can be seen as a type of indicator species for our groundwater ecosystem,” Dobbin says. “They have the shallowest wells that are the first to dewater and most prone to contamination.” By making sure that GSAs prioritize these communities and their access to clean water, Dobbin says, “we center equity and we can make the most gains in advancing sustainable groundwater management.” 

Dobbin points out that SGMA necessarily interacts with Assembly Bill 685—The Human Right to Water in California—which was passed in 2012 and made the state the first to legislatively recognize a human right to safe, clean, and affordable drinking water. “The success of these two policies is intricately bound together,” she says. “We cannot realize the human right to water without sustainable groundwater management, and we cannot achieve sustainable groundwater management as defined in SGMA without adequately accounting for vulnerable drinking water users of groundwater.”

Community members in vulnerable towns can provide insight into the challenges they face, but ensuring that their voices are fully considered can be difficult. Dobbin worked with one man who was the president of a tiny public agency providing drinking water for an unincorporated community of just a few hundred homes. He knew that being involved with SGMA was critical for ensuring his community’s long-term access to safe drinking water, but meetings were held during working hours, several towns over, and meeting announcements and cancellations were regularly sent via email, which he didn’t have regular access to. These and other factors can create real barriers for participation in the process. 

Fifty years ago, if you’d asked the average Californian about the role of UC Cooperative Extension, they’d probably tell you it was something like helping farmers grow bigger strawberries with fewer mushy spots. But as the work of extension specialists like Bruno and Dobbin shows, the mandate has broadened and become more nuanced. When it comes to SGMA—a massive bureaucratic attempt to combat a seemingly intractable problem—extension is crucial to guiding the concrete actions needed to achieve California’s high-minded goals.

Dobbin, for her part, is excited about the way in which extension benefits a wider swath of stakeholders than have traditionally had a voice in agricultural decision-making. “Sometimes there is this belief that university research is too wonky for many people to understand,” she says. “But my experience has been that people of all backgrounds are driven by the idea of answering questions to help advance solutions to water problems. We can deploy information into communities, but with SGMA it’s also about closing the loop and bringing knowledge back from the field to the policymakers.” 

Both Bruno and Dobbin occupy a critical space between lawmakers and policy professionals and the local residents, farmers, and water managers making day-to-day decisions about how to allocate water. The ability to link these groups will be key as SGMA reaches full implementation. Bruno—who regularly speaks and publishes policy briefs about her research on groundwater pricing and other water issues—was awarded a New Innovator in Food & Agriculture Research Award from the Foundation for Food & Agriculture Research to support her SGMA-related work. In January, Dobbin was appointed to the advisory group for the California Water Board’s Safe and Affordable Funding for Equity and Resilience (SAFER) program, which was launched in 2019 in part to realize the mandates of AB 685.

Whether it’s the residents of Teviston trucking in drinking water, small-scale farmers deciding whether to fallow their land, or massive pistachio-growing corporations trying to predict the long-term viability of their crop, every Californian has a stake in groundwater management. As the state faces climate change and drought, SGMA can either be a powerful conservation tool or a worthwhile endeavor that never quite finds its footing.

Success over the coming decades will require a delicate balancing act between competing interests and an effort to include the small farmers and drinking water districts impacted by water inequity in California. “I’m excited about the way UC is putting resources behind serving a broad population of Californians and doing everything we can to reach all Californians,” says Dobbin. “This is the mission of Extension and a way for the University to provide a truly public service.”