Water Supply – Public Policy Institute of California

Will Groundwater Sustainability Plans End the Problem of Dry Drinking Water Wells?

In the midst of the COVID-19 crisis, work continues on managing groundwater for long-term sustainability, as required by California’s landmark Sustainable Groundwater Management Act (SGMA). In January, water users in 21 critically overdrafted basins delivered their groundwater sustainability plans to the state Department of Water Resources. In this series, we examine the 36 plans submitted for 11 critically overdrafted basins in the San Joaquin Valley—California’s largest farming region, where excess pumping is a major challenge.

Why are drinking water wells going dry in the valley?

In the San Joaquin Valley, groundwater is the primary source of drinking water. While groundwater levels in the valley have generally been declining for decades, the problem of overdraft—which can cause shallow wells to run dry—is particularly acute during droughts as surface water supplies for irrigating crops are limited. This especially affects domestic wells and small community wells, which tend to be shallower than those used for irrigation or large urban water systems. During the 2012–16 drought, 2,600 well-dependent households reported water shortages across the state; almost 80% of these were in the San Joaquin Valley. We estimate that the valley’s total number of dry domestic wells was likely higher (see map below, on left). Many small community wells also faced shortages.

Does SGMA protect wells from running dry in the future?

SGMA was enacted to address the negative consequences of groundwater overdraft. Declining water levels is one of the six undesirable results that plans must avoid. Local agencies are tasked with setting minimum water level thresholds to avoid effects that are “significant and unreasonable”—something that can vary with local conditions.

Allowing some flexibility is important, because very restrictive thresholds would require immediate and costly cuts in groundwater pumping. Yet in many places, additional water level declines can render shallow drinking water wells useless. If agencies choose to allow continued pumping to avoid major disruptions in the regional economy, they are required to mitigate any significant and unreasonable effects. Options include covering the costs of drilling deeper wells or providing an alternative water supply.

How do groundwater plans address risks to domestic wells?

The plans reflect a range of approaches—as shown in the map below, on the right. In several basins, plans set water level thresholds to protect domestic wells from going dry. Some other plans acknowledge that their thresholds might cause some wells to go dry, and these already have a mitigation program in place or propose considering mitigation in the future. Plans in the remaining basins either do not discuss the potential impacts their thresholds have on domestic wells or do not consider these impacts to merit action. This includes the Kings Basin—home to a dense network of well-dependent communities—where three plans acknowledge that roughly 600 domestic wells may go dry, but do not consider this a significant and unreasonable impact of continued overdraft.

Is mitigation a good alternative?

Chowchilla and Madera basins also have some domestic wells at risk and have conducted economic analyses to compare the costs of two alternatives: rapidly reducing agricultural pumping to maintain higher water levels, or replacing domestic wells that would be affected. At a cost of $25,000 per well, the full costs of replacing affected domestic wells in Chowchilla ($130,000) and Madera ($770,000) are orders of magnitude lower than the costs of reducing agricultural pumping sooner ($581 million in Chowchilla and $968 million in Madera). This shows that it can be more cost effective for a basin to provide assistance to domestic well owners than to set restrictive water level thresholds that would result in large and abrupt losses in the local economy.

What’s next?

Although SGMA doesn’t protect every well from going dry, it does require plans to consider this problem and mitigate significant and unreasonable effects. At a minimum, the state should require that each plan quantify the impacts of its water level thresholds on drinking water supplies.

Increasing community participation in groundwater planning efforts is another priority. And as groundwater sustainability agencies grapple with how to bring their basins into balance over the coming decades, better information will also be key to improving decision making and reducing conflicts. The Department of Water Resources began releasing well records several years ago. The next priority should be improving understanding of which wells are used for drinking water, which wells are abandoned, and other critical information.

Many shallow wells serve economically disadvantaged communities, making the stakes especially high. Because the San Joaquin Valley has a high share of water systems with water quality problems, it’s also important to consider solutions that address both water quality and water quantity whenever possible. In many cases, providing alternative sources of supply may be the best option for affected communities.

Sinking Lands, Damaged Infrastructure: Will Better Groundwater Management End Subsidence?

In the midst of the COVID-19 crisis, work continues on managing groundwater for long-term sustainability, as required by California’s landmark Sustainable Groundwater Management Act (SGMA). In January, water users in 21 critically overdrafted basins delivered their groundwater sustainability plans to the state Department of Water Resources. In this series, we examine the 36 plans submitted for 11 critically overdrafted basins in the San Joaquin Valley—California’s largest farming region, where excess pumping is a major challenge.

What is subsidence, and why does it matter?

Excess groundwater pumping can compact soils, causing land to sink. Because this subsidence can damage costly infrastructure, avoiding it is an important reason to manage groundwater.

Subsidence due to groundwater pumping has been occurring in the San Joaquin Valley for almost a century, but it accelerated during the 2012–16 drought. Subsidence has damaged some critical water conveyance arteries, including the Friant-Kern Canal (40% of capacity lost in some stretches), and the California Aqueduct (more than 20% of capacity lost). Bridges over these and other canals are sinking, a local dam can’t hold water anymore, and stretches of the high-speed rail track have been designed to prevent damage from future subsidence.

Subsidence can also permanently reduce the capacity of aquifers to store water. Valley aquifers may have lost as much as 3.25% of their capacity from soil compaction during the 2012‒16 drought.

This infrastructure damage doesn’t just affect the individual farms or water agencies that are pumping groundwater—it affects other parties, both locally and many miles away. Mitigating damage will cost many millions, if not billions, of dollars.

How does SGMA require plans to address subsidence?

Under SGMA, land subsidence is one of the six undesirable results that every groundwater sustainability plan should seek to avoid. Plans must define indicators to track subsidence over time, and set thresholds to avoid “significant and unreasonable” impacts.

In principle, this framework allows plans to be more tolerant of continued subsidence in places that will not incur as much damage—for instance, in areas without major infrastructure. Local pumpers have an interest in this flexibility, because avoiding subsidence generally requires significantly curtailing groundwater use, and this curtailment is especially costly during droughts. But to be sure they are not causing harm, plans need to consider the consequences of subsidence for other parties—many of whom are not part of the local groundwater planning process.

Are the plans taking adequate steps?

In practice, the plans vary widely in their approaches to addressing subsidence. In several areas where infrastructure has already been damaged, agencies are setting thresholds to avoid additional subsidence. For instance, in the Chowchilla basin and parts of Delta Mendota, goals include avoiding further damage to local conveyance infrastructure and to levees that provide flood protection. But most plans set thresholds that are not tied to specific past or future impacts. And many of these thresholds are quite high—allowing the rates of land subsidence observed during the recent drought. This raises the risk of future harm, even in areas that have not yet experienced damage.

The figures below show subsidence rates over the past five years—which included both wet and dry years—alongside the cumulative amount of subsidence that the plans would allow over the next two decades. Recent subsidence rates are measured using satellite data, funded by the Department of Water Resources. Many plans are giving themselves a lot of leeway over the next 20 years, in some cases accepting 10–15 feet of additional subsidence. Even the lower thresholds in some sensitive areas might not end infrastructure problems and conflicts. For instance, the Friant Water Authority has warned that plans in the Tule basin will further reduce capacity in the Friant-Kern Canal, significantly affecting downstream water users. Similarly, the Department of Water Resources found that an additional 2.1 feet of subsidence in some sections of the California Aqueduct could further harm downstream water users. This is roughly one-third of the maximum amount allowed in the vicinity of the aqueduct by the Westside basin plan (6 feet).

What’s next?

The valley’s groundwater plans are at an early stage in tackling land subsidence. One important next step will be strengthening the information base for effective management. The paucity of public monitoring data raises challenges for local efforts. Continued state support for annual valley-wide surveys using satellite data could reduce overall monitoring costs and facilitate early identification of subsidence hotspots. The state should also press water users to provide more robust assessments of the risks of future subsidence in their plans.

Water Availability for San Joaquin Valley Farms: A Balancing Act

Why does surface water access matter for groundwater sustainability?

Although the San Joaquin Valley has the largest groundwater deficit in the state, water resources vary considerably within the region. A few areas receive abundant surface water. Most others supplement with groundwater. Still others depend entirely on groundwater. In many areas, groundwater is being used at unsustainable rates and pumping will need to be cut to bring basins into balance.

Irrigated agriculture is a major industry in the valley, and the largest water user. Our in-depth study of water solutions for the region found that ending overdraft will entail fallowing at least 500,000 acres of farmland. Access to surface water will be a key factor in determining which croplands stay in production, and which lands are retired.

How does surface water availability vary across valley farmland?

Last year we identified the location of groundwater-only croplands. Our newly compiled dataset allows a much richer view of surface water availability across the region. The maps below show surface water per acre of irrigated agriculture, using average water deliveries from 2001‒15 and cropland mapping from 2016. Surface water averages 1.8 acre-feet per acre valleywide, but availability varies widely both within and across basins. As a rough guide, lands with less than 3 acre-feet per acre of surface water generally need to supplement with groundwater. The less surface water there is, the more groundwater is needed.

How does the growth in perennial crops affect approaches to sustainability?

Since the early 1980s, the valley has seen a sustained shift from annual crops to perennial fruit and (especially) nut orchards. Perennial crops now occupy nearly 60% of irrigated lands. More than 20% of perennial acreage is on groundwater-only lands.

The expansion of orchards has benefitted the regional economy, enabling valley agriculture to generate more GDP and jobs than would have occurred if farmers had not made this shift. But perennials are less flexible, because they need to be watered every year to maintain the investment. With groundwater cuts looming, areas with little or no surface water are on the front line of the effort to bring basins into balance. Inflexible approaches to managing this transition could result in unnecessarily large, undesirable reductions in high-value crop acreage, regional employment, and GDP.

What solutions are different areas pursuing?

Bringing basins into balance will require expanding water supplies or reducing water demands. The new groundwater sustainability plans generally emphasize new supplies—with groundwater recharge projects and a variety of efforts to expand or extend surface water deliveries. Fewer plans focus on demand, and those that do give few details on their approach. By our estimates, the plans are too optimistic about the availability of new supplies, and more demand management efforts will be needed.

Basins with less surface water for irrigation are more likely to include demand management as part of their portfolio. For instance, water-short Madera County outlines a range of efforts to augment recharge and to purchase surface water from more water-rich areas. But it also anticipates the need to gradually reduce groundwater pumping by nearly 120,000 acre-feet in the Madera and Chowchilla basins.

Only a few areas—mainly some districts in Kern—propose incentives for flexible demand management to reduce groundwater use. This includes pumping fees, voluntary land-purchase programs, and groundwater trading that enables farmers to reduce use on the least productive lands and keep the most valuable lands in production.

Incentives that encourage farmers to trade groundwater locally—and to trade surface water both within and across basins—can make a big difference to the valley economy. We estimate that trading can reduce the regional costs of ending overdraft by two-thirds.

What’s next?

The valley’s variable water conditions call for managing groundwater sustainability at a regional scale. This scale is appropriate for considering many recharge investments, such as expanding regional conveyance to help get unclaimed floodwaters to suitable recharge areas. It is also necessary to help assess the land use implications of valley-wide surface water trading, which has the potential to keep the most valuable croplands in production while putting fallowed lands into new productive uses. Scaling up this work will require collaboration across a broad sector of valley stakeholders—together with their state and federal partners—in much wider and more comprehensive ways than ever before.

Note: The underlying data and additional notes on surface water availability in the valley can be found in Data Set: PPIC San Joaquin Valley Surface Water Availability. The data on supply and demand options identified in the groundwater sustainability plans is located in Data Set: PPIC San Joaquin Valley GSP Supply and Demand Projects.

Allocating Floodwaters to Replenish Groundwater Basins

In the midst of the COVID-19 crisis, work on managing groundwater for long-term sustainability continues, as required by California’s landmark Sustainable Groundwater Management Act (SGMA). In January, water users in 21 critically overdrafted basins delivered their groundwater sustainability plans to the state Department of Water Resources. In this series, we examine the 36 plans submitted for 11 critically overdrafted basins in the San Joaquin Valley—California’s largest farming region, where excess pumping is a major challenge.

How can floodwaters reduce groundwater overdraft?

Water users have two options for bringing overdrafted groundwater basins into balance: reduce pumping or increase groundwater supplies. In many places, recharging basins with floodwaters from winter and spring storms is one of the most promising supply-side approaches. With SGMA, interest in capturing this water is at an all-time high. In the San Joaquin Valley, 28 of the 36 groundwater sustainability plans propose recharge projects. Total demand for floodwaters is so high that it outstrips what is likely to be available. Competition could be fierce.

Allocating this water is the state’s responsibility, and developing an effective allocation system is a top priority for successful SGMA implementation. Ideally, this system should allocate floodwaters to generate the most benefits and encourage cooperation among parties to realize these benefits in the most cost-effective ways.

What is the state’s current approach for allocating floodwaters?

Previously, some water users have tapped unclaimed floodwaters for recharge, but there hasn’t been a formal permitting process until very recently. In 2019, the legislature enacted AB 658, authorizing the State Water Board to grant temporary permits to groundwater sustainability agencies and other public agencies to divert certain floodwaters. Based on this authority, the board also recently announced a permit system to establish permanent rights to divert and store floodwaters. This recharge water can be used to address various “undesirable results” of groundwater extraction as defined in SGMA, and diversions are limited to prevent harm to other legal users and aquatic species.

As with California’s system for permitting water rights, permanent rights to divert floodwaters will generally be allocated by seniority; those who first establish valid claims will have priority. Temporary permits will likely follow a similar priority system when water is available after satisfying the permanent rights.

Although these changes should make it easier to implement recharge projects, there are important shortcomings. Allocating water by the date of claim does not ensure it will be used to deliver the greatest benefits. It also encourages parties to fight to get to the head of the line, rather than to cooperate and plan to make the best use of this scarce resource.

Could an auction system improve the process?

In a recent article with colleagues from UC Berkeley and the Department of Water Resources, we proposed an auction approach as an alternative way for the state to allocate floodwaters for recharge. As in the current system, the state would set limits on how much water could be diverted within a watershed. But rather than simply apply for the right to divert and store high flow waters, parties would bid for this right.

Although parties would still be competing for the right to divert, this bidding process also encourages cooperation. To improve their chances of being selected, beneficiaries will have incentives to develop joint bids. Cooperative projects within and across groundwater basins will often have the best potential to mobilize funds for the investments needed to capture and use these waters.

By teaming up, parties can also develop projects that use the best locations for recharge—thereby lowering costs of this new supply. Bidding could also encourage cooperation with other beneficiaries—such as flood control districts that could benefit from reduced levee erosion or environmental groups who seek to increase wetland habitat on recharge lands.

Funding is another key difference between auctions and the current system. Right now, permittees pay a fee to cover administrative costs, but they do not pay for the water itself. In an auction system, the winning bidders would pay for the water. These funds could be used to support regional water management goals.

In short, the bidding process would spur creative, collaborative approaches to make the best use of recharge waters—with projects that bring the most benefits for the least cost. This would be a marked improvement over the currently planned “first-in-time, first-in-right” selection process, which does not explicitly consider the relative merits of competing proposals.

What’s next?

An auction approach can help coordinate stakeholders and improve the allocation of unclaimed floodwaters for recharge projects. Although legislation may be required to authorize it, existing California water law does not present an obvious impediment to adopting an auction system. Given its potential advantages over the current system, the state may wish to trial a round of auctions in river systems where recharge resources are likely to be scarce.

Note: The data on supply and demand options identified in the groundwater sustainability plans is located in Data Set: PPIC San Joaquin Valley GSP Supply and Demand Projects.

Wastewater Treatment Kills Most Pathogens, Including COVID-19 Virus

[vc_row][vc_column][vc_column_text]Californians reuse treated wastewater as a water supply, to irrigate crops, and to support freshwater ecosystems. To get answers to questions about managing the new coronavirus in the “sewershed,” we talked to two experts: Kara Nelson, an expert in waterborne pathogens at UC Berkeley; and Adam Link, executive director of the California Association of Sanitation Agencies.

PPIC: What risks does COVID-19 virus pose in wastewater?

Kara Nelson

KARA NELSON: We now have evidence that infectious coronavirus is excreted in the feces of infected individuals. The good news is that in the US, we already assume wastewater is full of high concentrations of infectious organisms like viruses, and we have practices in place to deal with them—including ways to protect workers from exposure. Coronaviruses have a different structure from the viruses we usually worry about in wastewater, such as hepatitis A and norovirus—and that structure likely makes it easier to kill. This gives us a high degree of confidence that we have effective treatment to manage the COVID-19 virus. So yes, there are risks, but all the information we have suggests that our existing practices reduce the risk to very, very low levels.

PPIC: Is the virus a risk in the reuse of treated wastewater?

KN: Producing safe, reusable water from wastewater already requires removing pathogens from it. While existing treatments—which are based on science and a regulatory approach developed over many decades—are likely sufficient to deal with coronavirus, we would like to see research that confirms this. Studies have already been launched in California and elsewhere to ensure measures we have in place are sufficient.

The heightened public interest in the virus provides professionals in the water industry an opportunity to share information about why reusing treated wastewater is safe and why we have a very high degree of confidence on how these risks are being managed.

PPIC: What’s the story with “flushable” wipes?

Adam Link

ADAM LINK: This was already a significant issue for us, and the pandemic has brought a huge new influx of wipes and cleaning-product debris into the system. Some wipes are marketed as flushable but don’t actually break down the way toilet paper does. They can sometimes form sizeable sewage blockages that damage pumping infrastructure, cause overflows, and increase our capital costs. CASA and many of our members are engaged in public information campaigns on the problem. Our agencies are working around the clock to keep systems functioning properly and prevent major breakdowns.

PPIC: Do you foresee any long-term impacts from the pandemic for the wastewater sector?

AL: In some ways we are similar to a business, and we have to think about the potential financial impacts of a recession on our systems. There are new orders to not terminate service if payments don’t come in, and we’re likely to see more people who struggle to pay their bills as a result of the financial downturn. So we need to put thought into planning for a new financial future. Our agencies are very good at long-term planning for capital projects, but it remains to be seen how dramatically this will change things from our current expectations. Much depends on the level of stimulus and how quickly things get back to normal.

PPIC: What gives you hope right now?

KN: The agencies and their workers—they’re putting their responsibility to deliver essential services first, before themselves, just like health care workers.

I’m also impressed with how quickly the research community has responded with new research on coronavirus and water. Therapies, tests, and vaccines are obviously the immediate priorities, but water researchers around the world have kicked into high gear to find long-term strategies to fight this and other emerging viruses. One exciting development is a global effort to monitor wastewater for the virus to quickly assess its prevalence in the sewershed; this could potentially help determine if infections are reemerging so we can respond quickly to contain them.

AL: I’m very encouraged by how well our agencies have come together to solve the new problems the pandemic raises and prepare for the worst together. There haven’t been any significant disruptions—and that’s thanks to the lengths these people go to keep the public safe.[/vc_column_text][/vc_column][/vc_row]

Groundwater Sustainability Planning Undeterred by COVID-19

COVID-19 has forced many of us to find creative ways of working together while sheltering in place. For California’s new groundwater sustainability agencies (GSAs), that means bringing together diverse groups of stakeholders in virtual forums to develop and implement state-mandated groundwater sustainability plans. We talked to Dave Ceppos—who, as managing senior mediator at Sacramento State’s Consensus and Collaboration Program, is working with many GSAs—about how the pandemic is affecting the complex public outreach process required by the Sustainable Groundwater Management Act (SGMA).

PPIC: Talk about how the pandemic lockdown is affecting the groundwater sustainability planning process.

DAVE CEPPOS: Unlike other public engagement laws and regulations, SGMA requires a dialogue between a GSA’s leadership and affected stakeholders. Planning and decision making need to take into account not only technical information about local groundwater basins, but also social information about water uses and needs. The GSAs have to show they’ve gotten input from water users, and that they’ve considered the impacts of their decisions on the local community. These conversations are hard and nuanced—basically, the GSAs are new regulatory agencies, the groundwater gods for their local area, and that’s a big change. Sheltering in place has made these complex conversations harder. I think GSAs are just getting their heads around the magnitude of the work they have to do under these new conditions, but they are rising rapidly to the challenge.

PPIC: How is the GSA community responding to limitations on public gatherings?

DC: In the past three weeks we’ve seen a pause in some places—the postponement of meetings that were coming up too fast to reconfigure to an online format, for example. But generally, work is continuing, and they’re taking it very seriously. My staff has already done probably six virtual SGMA public meetings. In the basins where plans are still under development, there is an outlying question about a possible need for an extension beyond the January 2022 deadline if the lockdown continues for a significant period of time, but for now it’s business as usual.

The governor’s recent executive orders relaxing some rules about how public meetings are held have been extraordinarily helpful—without them our work would be almost impossible. Meetings are continuing virtually. The agencies we’re working with are fully committed on publicizing meetings and putting out public messaging, but they’re not being hamstrung by Brown Act requirements about having to hold meetings in public places.

PPIC: SGMA involves many players from diverse groups, living in rural areas that may not have adequate online infrastructure for virtual participation. What’s being done to ensure that public participation is inclusive and fair?

DC: Every GSA that I know of is doing their best in terms of their obligation and their commitment to actively engage with the public. That said, not everyone has access to the internet. Not everyone can get information online, or can print agenda packets, which can be mammoth. We have farmers who attend midday meetings by calling in from their trucks—they can’t toggle through those packages or watch an online Powerpoint presentation from their phones. This is a daunting process involving a lot of complex information.

The reality is that even before this current crisis, our society had moved to a digital world that has left some people behind. In conversations we’re having with agencies, there’s typically an immediate rush to the online tools with the most bells and whistles. But for a facilitator, the first question we ask is, “what do we need to accomplish in a particular meeting?” Then we try to find the tools and methods to do that. To facilitate SGMA dialogues, we know that some people call in and can’t use online resources. We seek to create equity in virtual discussions by toggling back and forth between people in the virtual room and those sitting in trucks and kitchens who need to weigh in over the phone. When it comes to fostering inclusive dialogue, it’s not the bells and whistles that do it—it’s structuring meetings and using facilitation methods to make sure equity is maintained.

This is a challenging time, but we will get through it. Facilitators call it “change management,” which is all about helping people through a new condition by setting new expectations and behaviors. The good news is we humans are excellent at this, and we’re doing it already. Whether we need to manage this change for six weeks or six months, we’ll prevail and continue with this important work.

Note: On April 8, Dave Ceppos will lead a webinar by the Groundwater Resources Association of California, “How to Engage in a Socially Distanced World.”

What’s the Plan to End Groundwater Overdraft in the San Joaquin Valley?

In the midst of the COVID-19 crisis, work on managing groundwater for long-term sustainability continues, as required by California’s landmark Sustainable Groundwater Management Act (SGMA). In January, water users in 21 critically overdrafted basins delivered their groundwater sustainability plans to the state Department of Water Resources. In this series, we examine the 36 plans submitted for 11 critically overdrafted basins in the San Joaquin Valley—California’s largest farming region. PPIC has done extensive work on what SGMA means for this region, where excess pumping is a major challenge. This post examines how the plans propose to end overdraft.

What are the options for ending overdraft?
SGMA requires water users to bring their groundwater basins into long-term balance over the next two decades. Although there are no easy solutions, the math is simple: bringing these basins into balance will require expanding water supplies, reducing water demands, or a combination of these two approaches.

Our in-depth study of water solutions for the San Joaquin Valley found that about a quarter of the region’s 1.8 million acre-feet (maf) of annual overdraft could be filled with new supplies at a cost that local water users can afford. Among supply options, by far the most promising approach is expanding groundwater recharge: storing more of the runoff from large storms in underground aquifers. Filling the remaining three-quarters of the gap will likely require demand reductions. Since agriculture is the predominant water user, this will entail taking some farmland—at least 500,000 acres—out of production. Giving farmers the flexibility to trade water—so it can be used on the most productive lands—can reduce the costs of ending overdraft by two-thirds.

What do the new groundwater sustainability plans propose to do?
As the figure below shows, the plans consider a range of projects on both the supply and demand sides. Together, these projects would yield roughly 2.2 maf per year—in principle, enough to end regional overdraft. However, the plans invert our estimates: they assume that new supplies will account for more than three-quarters of the total, while demand management will save less than one-quarter. In line with our analysis, the single biggest new supply is recharging groundwater basins with more floodwater: the plans target roughly 1 million acre-feet annually, primarily through many small, local projects. Big infrastructure investments—such as new surface reservoirs and regional aqueducts and canals—are largely left out.

Are the goals for expanding supplies realistic?
Probably not. When it comes to recharge, water users will be competing for floodwater that can be feasibly captured—likely a much smaller volume than the total envisaged by the plans. Although that total might be physically available for recharge, there are serious capacity constraints to getting it underground. A central challenge is moving very large volumes of water to storage sites quickly. Addressing this challenge is likely to require regional investments in conveyance, and greater efforts to coordinate the management of surface and groundwater storage infrastructure in order to expand their combined impact. Even then, it is probably not feasible to capture all available water in very wet years.

There are also limitations for the other supply options. Most surface storage and surface water treatment projects will be looking to capture the same high flow water as recharge projects—heightening the competition for these supplies. And most surface water trading and recycled water projects will shift available supplies from some water users to others within the region, rather than causing an overall increase in regional supplies.

What about the plans for reducing demand?
For the most part, the plans fall short on their analysis of demand management. Since reducing water use in this region largely means reducing the amount of irrigated cropland, there’s been reluctance to seriously consider the demand side at this early stage of SGMA implementation. But it’s encouraging that at least some plans are starting to look at such options. Several plans propose tools for managing demand flexibly—for example, groundwater trading, fees tied to volumes pumped, and monetary incentives for land fallowing.

What’s next?
These new plans are an early step on the path toward groundwater sustainability. As implementation gets under way, early actions—such as piloting new approaches to manage demand flexibly and coordinating on smart and affordable supply investments—can lay the foundation for long-term success.

Note: The underlying data and additional notes on supply and demand options identified in these plans can be found in Data Set: PPIC San Joaquin Valley GSP Supply and Demand Projects.

COVID-19: Not a Threat to California’s Water Supply

The COVID-19 health emergency has prompted “panic buying” of bottled water that has emptied store shelves and sown confusion over water safety. We talked to Dave Eggerton—executive director of the Association of California Water Agencies (ACWA) and a member of the PPIC Water Policy Center advisory council—about the state’s municipal water supply in light of the ongoing pandemic. ACWA is a statewide association whose 450 local public water agency members are responsible for about 90% of the water delivered in California.

PPIC: Is the state’s water supply safe?

DAVE EGGERTON: The virus is not a danger to our public water supplies, and buying bottled water in response to it is unnecessary. This has been confirmed by the US Environmental Protection Agency, the Centers for Disease Control, and many local water suppliers. Our treatment plants use a disinfectant process that destroys this virus, along with other pathogens that threaten public health. After the water is treated, chlorine is added during the delivery process as an added precaution.

Our public water systems are comprehensively regulated under state and federal law—including the removal of pathogens. The men and women who operate these plants are highly trained to manage crisis situations like this. These people are real heroes in the work they do, and we’re incredibly proud of them, and of the fact that our water supply remains safe.

In addition to providing this essential service, one of the other important things our water agencies do is continuously provide timely, accurate information to the public. That’s a major focus right now, and it’s key to reducing confusion during a crisis. If you have any questions about water safety, contact your local provider; they stand ready to help.

PPIC: Water systems are critical infrastructure and can’t shut down. What steps will the sector need to take to address this risk?

DE: Like the rest of society, we’re faced with the challenge of protecting our employees from getting sick. Public water systems are in many ways automated, which allows us to operate facilities more or less remotely. But you need essential workers on site to monitor conditions at treatment plants and distribution systems and address issues as they arise. These people must be able to get to work sites. So we have to protect them so they can do their jobs.

That said, the water sector is well prepared for emergencies, so you can be sure these supplies will be delivered to people’s homes. For example, if you look back at some of the recent catastrophic fires we’ve experienced, water workers were at frontlines to protect communities’ supplies. They have an incredible commitment to their work. Responding to emergencies is something our agencies do on a regular basis. We have emergency response plans, and the men and women who operate these systems are trained to handle crisis conditions. During Santa Rosa’s huge fire, for example, operators of a water treatment plant kept it functioning so water could continue flowing to hydrants, even when they were at risk of the rapidly approaching flames.

In addition, our agencies are working together to help each other—we have mutual aid agreements to share supplies and labor as needed. And because our drinking water systems are regulated under state law, the state Division of Drinking Water has continuous involvement with our public agencies. So we have longstanding relationships and paths of communication that enable us to be aware and responsive to new challenges. And on the local side, we have strong, ongoing relationships with county response emergency operation centers, and we’ve planned emergency scenarios with them. That level of communication and trust really helps in times like these.

A Reality Check on Groundwater Overdraft in the San Joaquin Valley

This year marks a new phase in California’s landmark Sustainable Groundwater Management Act (SGMA). At the end of January, water users in 21 critically overdrafted basins delivered their first groundwater sustainability plans to the state Department of Water Resources. In this series, we examine the 36 plans submitted for 11 critically overdrafted basins in the San Joaquin Valley—California’s largest farming region. PPIC has done extensive work on what SGMA means for this region, where excess pumping is a major challenge. This post addresses key questions about groundwater budgets.

What are water budgets, and why do they matter?
Water budgets track the water coming into and going out of the groundwater basin. If more groundwater is pumped than the amount replenished over time, the basin is in overdraft. In our study of the valley’s 30-year water balance (1988‒2017), which used data on inflow and outflow to the San Joaquin Valley as a whole, we found a long-term overdraft of 1.8 million acre-feet per year—about 11% of net water use.

Under SGMA, water users need to bring their basins into long-term balance and avoid undesirable effects from excess groundwater pumping—such as lowering groundwater levels and causing lands to sink. Understanding the extent of the overdraft problem is key to taking appropriate action. As the saying goes, you can’t manage what you don’t measure.

What type of groundwater budgeting does SGMA require?
The regulations require groundwater sustainability plans (GSPs) to include three types of water budgets—historical, current, and projected—but allow a lot of flexibility on the specifics. Historical budgets only need to include 10 continuous years of data, including the most recent years available for that basin. Current budgets need to show present-day conditions, and projected budgets need to look ahead 50 years and consider anticipated changes in population, climate, and other factors that could affect water supplies and demands. The plans can then choose which budget to emphasize for addressing overdraft.

In many basins, water users have opted to develop separate GSPs for different areas. In those basins, the GSPs must use a common timeframe and a common overall budget. But there’s no requirement for consistency across neighboring basins. The regulations also leave it up to locals to choose their methods for elements that must be estimated, such as how quickly groundwater moves from one basin to another. Budgets can look better or worse depending on assumptions about such factors.

The span of years covered by budgets can also matter a lot, given California’s variable climate. Budgets with more wet years will look better than budgets with more dry years. The figure below shows the budget timeframes that the valley’s plans use for their preferred estimates of overdraft. These timeframes vary widely. Basins in the wetter northern part of the valley (the San Joaquin River hydrologic region) are more likely to include the recent drought than are the basins in the drier, more groundwater-dependent southern valley (the Tulare Lake Basin hydrologic region).

Do the plans acknowledge the valley’s overdraft problem?
In general, yes. As the figure below shows, the plans report a considerable amount of overdraft—around 1.4 million acre-feet (maf) per year. But since they cover different timeframes, it’s misleading to simply add up the totals reported. To compare apples to apples, we looked at the eight years that are included in all of the budgets: 2003‒10. This short period is instructive, because it includes both wet and dry years. The plans estimate around 1.7 maf of annual overdraft in these years—fairly close to our valley-wide estimate of 1.9 maf for the same period. So overall, the plans are telling a story that is broadly consistent with the overall regional water balance. This apples-to-apples comparison also reduces the wet-year bias in many of the Tulare Lake Basin budgets.

Even so, some basins are probably underestimating overdraft. And if the future is drier than the past, the overall challenge for the valley could be greater. We found, for instance, that the region-wide overdraft for 2003‒17—a period that included a record-breaking five-year drought—was 2.4 maf/year—a good deal higher than the 30-year average of 1.8 maf.

What’s next?
Acknowledging overdraft is important, but it’s just the first step. The options to end overdraft include augmenting water supplies, reducing water demand, or some combination of the two. Next week’s post will examine what the plans propose to do.

Note: The underlying data and additional notes on the water budgets used in these plans can be found in Data Set: PPIC San Joaquin Valley GSP Water Budgets.

Why the Big Drop in California’s Colorado River Water Use?

In 2019, California’s use of the Colorado River—a major water source for Southern California’s cities and farms—dropped to the lowest level in decades. We asked John Fleck—director of the University of New Mexico’s Water Resources Program and a member of the PPIC Water Policy Center research network—about the ongoing changes in California’s use of this water, and what it means going forward. He is the author, with Eric Kuhn, of the new book Science Be Dammed: How Ignoring Inconvenient Science Drained the Colorado River Basin.

PPIC: What are the main reasons Californians are using less Colorado River water?

JOHN FLECK: The biggest reason for the recent drop is that Metropolitan Water District (MWD)—the state’s biggest urban user of the river—didn’t need to take as much water in 2019. But this decline also reflects a longer term trend. Prior to the early 2000s, MWD generally took the maximum it could from the Colorado River, usually more than a million acre-feet per year. In recent decades, it has substantially reduced its dependence on the Colorado, only taking a full supply in years of State Water Project shortage. Water conservation has been an enormous success in Southern California. There was a lot of progress in conservation during the latest drought, and even after it ended. We’re seeing a lot more effective use of water in the basin, with a growing emphasis on groundwater recharge, stormwater capture, and reuse efforts. The excellent snowpack in the Sierra in 2019 meant the agency got a good water allocation from the State Water Project, meaning it needed less from the Colorado.

The other part of this story is the conservation success in the Imperial Irrigation District (IID)—the largest user of Colorado River water in the entire basin. On-farm water conservation was part of transfer agreements with Southern California’s urban water suppliers. IID is now using 600 thousand fewer acre-feet per year than before those transfers took place. The agricultural community took cuts and was compensated for them. Farmers have adapted well: revenue has held up even as they’re irrigating less land. What we’ve seen is an increase in acreage in high-dollar crops like winter lettuce and vegetables, and a reduction in alfalfa and forage crops, which bring in less revenue per unit of water and area of land.

PPIC: Do you expect similar drops in coming years in California or the six other basin states?

JF: We’re going to have ups and downs—especially because MWD use of Colorado River water tends to go up when its supplies from the Sierra are low. But California has really demonstrated that it needs less Colorado River water. It’s taken awhile, but it’s been a really successful adaptation. Scarcity is the norm now in the basin, so the fact that California can succeed in using less imported water is incredibly important. It shows how we can find opportunities for more flexible problem-solving going forward.

We’re seeing similar things going on across the basin. California isn’t giving up water so others can use more. Nevada is using substantially less than they used to—their use peaked in the early 2000s and has dropped since then. Arizona’s use is down, too. And we’re seeing really flat to declining use in all the other basin states. So the notion that economic and population growth means an increase in water use just isn’t the case in the basin.

PPIC: What does this change mean for efforts to bring the basin into balance?

JF: Because we made mistakes over a century ago in allocating more water than the river can provide, these successes are important, but not enough. We’ll need to see more reductions, especially in the lower basin states.

The next steps require renegotiating the rules that govern the basin’s water allocation to solve the basin’s problems. The Bureau of Reclamation is spending 2020 reviewing how the current rules are working, with the expectation that negotiations on new rules will begin soon after that review is complete. There will be a lot of give and take in how that will play out, and we have to let that happen. Once farmers and communities have a clear idea on how much water they will get, they’re pretty good at figuring out what steps are needed to work within those limits. Various options that might come into play include compensating farmers to use less water, additional conservation, and more expensive options like increasing the use of recycled water and building desalination plants. The negotiations will be hard, but the successes we’ve seen in California and elsewhere around the Colorado River Basin suggest that we have the tools needed to respond to the challenges to come.