Category: Water Supply

California Depends on Rivers—in the Air

Climate change could bring both bigger rains and longer droughts to California. What do the bigger rains mean for the state’s water management? We talked to Mike Dettinger—a research hydrologist with the US Geological Survey and a PPIC Water Policy Center research partner—about the weather phenomenon known as “atmospheric rivers.”

PPIC: What are atmospheric rivers?

Mike Dettinger: They are long pathways that transport water across the atmosphere. Typically they’re at least 1,200 miles long; the biggest can be five times that. They tend to evolve as they cross the Pacific. Those that manage to reach the West Coast meet a more-or-less abrupt end when they hit the mountains, dumping rain and snow in the process. These storms carry a lot of water—a big one can move up to 20 times the amount of water that comes down the Mississippi River. They can provide a third to half of our annual precipitation in just a few storms.

Because they’re usually warmer than other types of storms, larger areas of our river basins get rain rather than snow, which increases flood risk. In the past 60 years nearly all of our largest storms and most damaging floods were caused by atmospheric rivers. The largest ones have brought 12–16 inches of rain in a few days. On the plus side, they also bring ecologically beneficial flooding for wetlands and are a major factor in ending our droughts.

PPIC: Can we predict when these storms are coming?

MD: We’ve got about a decade of understanding atmospheric rivers in practical and useful ways. The California Department of Water Resources and others have responded by investing in an enhanced water monitoring network. These efforts and a lot of basic research have revolutionized forecasting of California’s largest storms, which is critical for reducing flood risks and managing water supply. A decade ago the weather service wouldn’t forecast storms beyond three days. Now we routinely receive forecasts of major storms a week or more in advance. We’re working to improve forecasting even more, especially in terms of the details of where and how intensely the storms will land. The hope is that better forecasting can allow dam operators to keep more water in reservoirs at the end of the rainy season while better managing flood risks.

PPIC: How might climate change affect these storms?

MD: As the world warms, the atmosphere will be able to hold more water. Climate models agree that we’ll see more atmospheric rivers—likely a doubling by the end of 21st century. How much water they’ll bring is less clear—some models show a 10–15% increase. But most of the increased rainfall will come from a larger number of these storms than from how much water they hold.

About half of climate projections show California getting wetter, while half show it getting dryer. If you dig a little bit, nearly all projections show an increase in the number of atmospheric rivers, and virtually all show a decline in other types of storms. That decline will bring more dry days, punctuated by these major storms. So if we indeed do get the wetter future, it’s because of more potentially dangerous atmospheric rivers. It’s a Faustian bargain.

We’ve spent a century building up a flood control system that tries to take the peaks off the worst floods. This has put our ecosystems at a disadvantage, as they evolved with regular floods. I think we’ll find it harder to control floodwaters as climate change builds, and that might tend to bring us back to something more like what California’s natural systems evolved under—allowing bigger areas to absorb floodwaters in winter. It will be interesting to see how we achieve balance and who will be the winners and losers. We have a lot to learn.

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TABLE SOURCE: Chart excerpted from The Meterorology of Extreme Orographic Precipitation in California—A Synthesis of 2014 (Ralph and Dettinger).

Improving Water Allocation During Droughts

The drought has been a stress test for California’s water system. Brian Gray—an adjunct fellow at the PPIC Water Policy Center and professor emeritus at UC Hastings College of the Law in San Francisco—is a coauthor of our new report Allocating California’s Water: Directions for Reform. We talked to him about its findings.

PPIC: How did our water allocation system fare during the drought?

Brian Gray: California is straining to meet a range of demands while also maintaining a healthy environment. Water rights matter most during times of shortage. In fact, their purpose is to define who is entitled to use water when there isn’t enough for all right-holders.

This drought was the first time the State Water Board curtailed water rights since 1977. Some senior water right-holders successfully challenged the board’s authority to apply the priority system to them. The board found it difficult to ensure that enough water remained in rivers to support at-risk fish species (many of which are protected by federal and state endangered species acts).

Because this drought is a harbinger of a “new normal,” we wanted to harvest its lessons. We found three key areas for improvement.

First, we believe the state can maintain its water-rights seniority system, but it must improve how water rights are administered. We should eliminate an archaic distinction between categories of water rights by bringing all surface water rights under the water board’s jurisdiction. We also need better information on water use and availability to enable more effective, real-time decision making.

Second, although we have legal protections for the environment, we don’t have a clear process for allocating water to critical environmental needs during droughts. We recommend that the water board define the amount of water required to protect fish, wildlife, and water quality within each watershed. This environmental water, along with water needed to protect public health and safety, would have top priority.

Finally, during droughts we need flexibility to allocate water to vital uses (such as domestic supply, permanent crops, and the environment) that may be short of water. Trading water can provide that flexibility. Yet during this drought trading was limited, in part because California’s water transfer rules are fragmented and inconsistent. We need to make it easier to trade water during droughts.

PPIC: Why shouldn’t the state create a new water rights system?

BG: There have been calls for a complete overhaul of California’s water rights system, which is quite complex and doesn’t always work smoothly. It’s unlikely that anyone would design this system today if starting from scratch. But water rights are property rights, so a wholesale change would raise significant constitutional questions under federal and state law. It’s probably better to maintain our system as long as we strengthen the water board’s oversight of water rights, and increase transparency and flexibility of water allocations. Improving information is key. Effective management requires that we know who has what water rights, how much they are diverting, and how much they are returning to the system following use.

We think the time is right to start making these changes toward a more efficient and fairer water rights system. The Sustainable Groundwater Management Act, the governor’s emergency drought orders, and other initiatives demonstrate that the state is ready for reforms. Many of our recommendations are not nearly as challenging as these. And they will help us manage water better during the next drought.

Learn More

Read our report What If California’s Drought Continues? (August 2015)

Testimony: Planning for Future Droughts

In a week that began with Governor Brown extending the statewide water conservation mandate into next year, a panel of experts testified about how to improve drought management. They spoke before the Assembly Select Committee on Water Consumption and Alternative Sources on November 17.

Nine experts covered a range of topics, including the state of our water infrastructure and management systems and options for improving water security as our climate becomes warmer.

Jay Lund, director of the UC Davis Center for Watershed Sciences and an adjunct fellow at the PPIC Water Policy Center, gave an overview of California’s complex water system and ways the drought has tested it. He noted the state suffered a water shortfall equivalent to three full Folsom reservoirs.

“We can’t drought-proof the state,” Lund said. “But we can do better in managing drought. In the future, there should be greater emphasis on improving our water markets and on storing more water in groundwater basins.”

I talked on key areas where we need to do better, as documented in our report What If California’s Drought Continues?:

  • Cities and suburbs: The state’s urban areas have weathered the drought well so far. But we’ve boxed our water agencies in by making it hard for them to raise rates and requiring cost accounting that is too precise. This makes it more difficult to invest in options like capturing stormwater and recycling wastewater.
  • Agriculture: Farmers increased groundwater pumping to make up for losses in surface water—a smart short-term thing to do. It can be smart for the long term too, as long as we get better at storing groundwater for drought years.
  • Rural communities: Our most vulnerable populations suffered from drying wells in areas that already had water quality problems. There’s a need for more sustained investment in safe water for rural communities.
  • Ecosystems: Our habitats and the animal life they support are in crisis from the dry, hot conditions. Wildfire risks are extreme, and many fish species are at risk of extinction. Rebuilding environmental resilience will be key to sustaining the state’s iconic biodiversity.

Noah Diffenbaugh, a climate scientist with the Stanford Woods Institute, described some risks that climate change brings to the state’s water systems. Warm years are becoming the norm, making droughts much harsher by shrinking the snowpack and drying out soils.

Peter Gleick, president of the Pacific Institute, talked about increasing conservation and prioritizing water investments. “We saved almost 800,000 acre-feet of water this summer. This is far more water than any of the proposed reservoirs would provide,” he said.

Buzz Thompson, director of the Stanford Woods Institute, talked about the role of technology in increasing California’s water security and resilience. “New technologies will be coming along in the next 5–20 years that will reduce our costs and give us more options. We need to do more to support them.”

The hearing also featured remarks from top administration officials, who described progress in implementing the governor’s Water Action Plan. An Israeli water expert shared that country’s experiences in wastewater recycling, desalination, and pricing to combat water scarcity.

The committee plans to hold additional hearings on water supplies and sources in the coming months.

Learn More
Read California’s Water: Climate Change and Water (PPIC fact sheet, April 2015)

Testimony: Paying for California’s Water Needs

How can we fund California’s most pressing water needs? And where are we falling behind in paying for a water system that works for all? A hearing convened by the Senate Natural Resources and Water Committee yesterday looked at these and other questions. I joined other speakers from nonprofit groups focused on water, local governments, and water agencies to discuss these challenges and how to address them.

Lester Snow, executive director of the California Water Foundation, set the stage, stating that California is “falling behind in central water resource investments, especially in terms of public health and climate adaptation.” Investing in watershed health and ecosystems will help our water supply and our ability to weather climate change, he noted.

My testimony focused on the need for adequate funding to ensure the long-term success of our water system. In some areas—such as water supply and wastewater treatment—we’re doing fairly well in keeping up with needed investments. As documented in our report What If California’s Drought Continues?, investments in water supply for cities and suburbs helped us weather the current drought. It will be important to maintain the momentum in those areas. But in other key areas, we’ve found significant funding gaps, including safe drinking water in many rural areas, ecosystem management, stormwater management, and flood protection. The total annual funding gap for these “fiscal orphans” is roughly $2–$3 billion.

Local governments have the most responsibility when it comes to funding water systems. But there are looming concerns—including rising costs to address aging infrastructure and new treatment standards—and more uncertainty about the ability of local agencies to raise rates to cover them.

The state’s funding mechanisms “remain fundamentally unchanged,” Snow noted, even as California strains to meet various needs for water. I noted that California must go beyond water bonds, which at best provide $1 billion per year in support, to create the sustainable funding we need for this essential service.

Snow and I both spotlighted how efforts intended to improve accountability have made it more complicated to fund water systems locally. Three constitutional reforms passed by voters since the late 1970s—Propositions 13, 218, and 26—changed the way Californians pay for water services. These measures have made it more difficult for agencies to raise money locally for water infrastructure and services.

Laurel Firestone, co-executive director of the Community Water Center, talked about the many challenges facing California’s rural poor and underserved communities, where access to safe and reliable drinking water has been a particularly challenging problem in recent years.

Addressing our ability to provide a safe water supply for the poor, enable local water providers to charge appropriate water rates to cover needed investments, and maintain healthy watersheds and ecosystems are some key areas where change is needed. In January, a second hearing by this committee will look more closely into scaling up solutions for meeting these challenges.

Learn More

View slides from Hanak’s presentation
Read the PPIC Water Policy Center’s briefing on paying for water
Read the in-depth PPIC report on water system funding

 

Video: Farming Solutions to Weather Drought

How is California’s drought affecting farming, rural communities, and the environment? How much water do farms use, and how do they benefit the state’s economy? What are farmers doing to improve how water is managed? These were some of the big questions discussed by a panel of experts at the October 20 event “Weathering Drought: Farming Solutions for a Thriving California,” organized by the nonprofit group Sustainable Conservation and held at PPIC’s Bechtel Conference Center.

Ashley Boren, Sustainable Conservation’s executive director, moderated the discussion with Ellen Hanak, director of the PPIC Water Policy Center; Karen Ross, secretary of the California Department of Food and Agriculture; Don Cameron, general manager of Terranova Ranch; and Kat Taylor, co-owner of TomKat Ranch.

The panelists talked about a range of water-management efforts that are being tried on the state’s farms. Terranova Ranch is the site of a particularly promising approach to water storage. Cameron said the farm is building infrastructure to funnel excess flood waters from the Kings River to fields, where it will soak into the ground. This helps replenish the groundwater basin—which has dropped after serving as a vital reserve over three years of drought—as well as reducing flood risk to downstream communities. Taylor described efforts to rebuild the health of the soils—another vital store of moisture—on the grazing lands at TomKat Ranch.

While acknowledging the challenges California is facing from the drought, the panelists also described positive changes underway. Ross noted that in her travels around the state’s agricultural regions, people are talking about unprecedented levels of cooperation to help each other get through the dry times. The message she’s hearing is we’re all in this together, and we’ll get through it by working together.

Learn More

Read Sustainable Conservation’s blog about the event
Read Reforming California’s Groundwater Management (PPIC fact sheet, June 2015)
Read our report What If California’s Drought Continues? (August 2015)

Coming Together Over Groundwater

California’s groundwater management took a forward-looking turn with last year’s passage of the Sustainable Groundwater Management Act (SGMA), which requires local planning efforts to protect the long-term viability of this critical resource. Sarge Green—a water management specialist at California State University, Fresno, and a member of the PPIC Water Policy Center’s research network—is working to put the groundwater law into practice at the local level. We talked to him about creative approaches being tried in the San Joaquin Valley.

PPIC: Talk about the regional groundwater management effort you’re involved in.

Sarge Green: I’ve been participating in a joint effort of eight counties in the San Joaquin Valley, which is looking at key issues—education, air quality, water, transportation. Water is now the top priority for this planning effort, not surprisingly.

The San Joaquin has the largest overdrafted groundwater area in the state. Our task is to find common tools or projects to improve our groundwater situation, and try to get support for them with state or federal grants. We’re designing a local groundwater ordinance with elements that address unsustainable groundwater extraction impacts and permits for new wells.

This valley is a study in contrasts. At one end is the Delta, and at the other end is a major importer of Delta water. Getting all the counties together was groundbreaking. Our organizing principal is: we agree on a majority of things having to do with water, but historically we’ve spent most of our time on the things we disagree on. We’re focusing on what we agree on and getting things done.

PPIC: What is a logical scale for managing groundwater?

SG: Groundwater knows no political boundaries. Basically there’s one big basin. The logical planning scale is the watershed—the areas around the rivers and the mountains that contribute to our valley groundwater. But one constraint in this part of the state is that a lot of people don’t want bigger government. So what’s happened is we’re working at smaller levels within the watershed, and breaking into governing units called groundwater sustainability agencies. Hopefully over time we’ll migrate to something more logical. Ultimately, we’ll need to tie groundwater management to the larger watershed.

PPIC: What’s currently keeping you up at night regarding the state’s groundwater reserves?

SG: It’s the loss of shallow water in rural communities, which is causing drinking water problems. In many cases, rural residents can’t afford to drill much deeper. In others they’re drilling to bedrock and still not getting water. Our basins will refill, but that won’t happen overnight. Financing is also an issue. Some counties are offering low-interest loans to help folks drill deeper. Some people will get covered by hooking into larger systems, which is being promoted by the state’s new push for consolidation. I’ve worked for a long time in rural communities, so I know many rural residents want to remain independent. Some don’t even complain when their wells run dry—they just wait on a drillers’ list and get the job done.

Learn More

Read Reforming California’s Groundwater Management (PPIC fact sheet)
Read “Getting to Groundwater Sustainability” (PPIC blog, June 16, 2015)
Visit the PPIC Water Policy Center’s water supply resource page

Do You Know Where Your Water’s Been?

The twin challenges of water quality and quantity are leading to creative thinking and interesting solutions in California and across the west. David Sedlak is helping find innovations in water re-use and treatment in his various professional endeavors. He’s a professor of environmental engineering at UC Berkeley, co-director of the Berkeley Water Center, deputy director of the ReNUWIt program, and a member of the PPIC Water Policy Center research network. We talked to him about the state’s water quality challenges and efforts to create more sustainable water systems.

PPIC: What might a lay person find surprising about water quality in California?

David Sedlak: Most people don’t realize the extent to which to we use water over and over again in the state. The water that’s flowing down a river might have recently been in a farm field or flowed over a city’s streets. Water picks up different contaminants depending on where it’s been. If it was used on a farm it might pick up salts or pesticides; if it came from a sewage treatment plant it might pick up pathogenic microbes or chemicals used in homes; if it ran off city streets it could pick up metals or oils. It’s still 99.99% water, but that .01% can make all the difference in the world—it’s this tiny amount of contamination arising from human activities that could make it unsafe to drink, spread disease, or kill fish.

PPIC: How does the quality of our drinking water supply constrain California?

DS: During the 20th century we created a system for moving extremely clean mountain snowmelt into our cities. The drought, population growth, and competition among water users have complicated things. New technologies enable us to make use of water resources that were previously thought to be unsuitable for drinking. These advances have allowed us to make major progress in reinventing the water system our grandparents built by making use of diverse sources they weren’t able to tap.

Nonetheless, these impaired water sources are more expensive to treat and deliver than the pristine sources that we relied upon in the past. We have the means to remove many of those contaminants, but it can be expensive. The cost of treatment depends on the source of water. We can turn seawater into drinking water, but that’s probably the most expensive source available to us. We can turn sewage treatment plant effluent into drinkable water for about half the price of desalination. We could also harvest the rain that falls in cities, but we don’t have a lot of experience in scaling it up. Los Angeles is starting to make progress on urban rainwater harvesting but this approach is still in its infancy, and it will require time to figure out if this is a good investment. Our Mediterranean climate means that many of our cities get the bulk of their annual rainfall in a few big storms. So if we’re serious about capturing rainwater we might have to build some pretty large structures, which would make the process expensive.

PPIC: What do you think needs to fundamentally change in our relation to water in the urban environment?

DS: Ultimately, members of public, community leaders and elected officials all need to step up and take responsibility for our water supply. We can’t leave it to the utilities to figure out alone. I’m very optimistic—we’ve already seen great progress. The water suppliers are starting to recognize that the public has to be part of the discussion. We’re definitely seeing positive behavioral changes now that the public is paying attention to the fragility of the water supply. It seems we’re becoming more willing to make sacrifices to pay for a modern water system that we want to leave to our grandchildren’s generation and those that follow them.

Learn More

Visit the PPIC Water Policy Center’s water supply resource page
Read our factsheet California’s Water Quality Challenges

Building a Better Water Safety Net

California’s poor rural communities have been hard hit by the current drought, which has brought drying wells and reduced water quality. Laurel Firestone is co-director of the Community Water Center, where she focuses on advocating for safe, reliable and affordable water supplies for vulnerable communities in the San Joaquin Valley. She was a speaker at an event to launch the PPIC Water Policy Center report What If the California Drought Continues?, which found maintaining safe rural water supply to be one of the biggest challenges of ongoing drought. Here she describes some of our water inequities, and ways to solve them.

PPIC: What are some successes arising from this drought?

Laurel Firestone: I think some of the biggest successes have been at the state level. First of all, the voter-approved water bond included half a billion dollars for small disadvantaged communities. The budget includes a lot of money for emergency drought response. Additionally, the drinking water program at the State Water Board has made huge strides in getting money to the communities. Bigger picture, the passage of the Sustainable Groundwater Management Act was essential. About 90 percent of communities in the San Joaquin Valley rely on groundwater, with many households using shallow wells that have gone dry as commercial wells have been drilled deeper.

On the local level, people are stepping up, too. Some cities have reached out to neighboring communities whose wells are running dry—for example, the city of Farmersville hooked up close to 100 homes whose wells were about to go dry. Some amazing volunteer and local service providers have been going door to door in some of the hardest hit areas. They’re helping get water to people who were already in dire circumstances and now also have to deal with turning on the tap and figuring out how they’re going to shower, feed their children, meet basic sanitation needs.

PPIC: If the drought continues, what needs to be done to improve water supply for poor, rural communities?

LF: There are a few main areas we’ll need to focus on. The first is that we have inadequate information on where households are going dry. We really don’t have a handle on this problem, particularly for private wells. The state’s plan for identifying vulnerable private-well communities and funding solutions to this problem is completely inadequate. We’ll have to quickly come up to speed to address this.

Renters have not been able to get state assistance to buy emergency water tanks. They have been able to get bottled water delivery, or have gotten help from private charities or churches. But we have millions of dollars in emergency drought funding, and it needs to get to people whether they own property or not. I know the state has been trying to get better at this, but there’s an urgent need for better coordination between the state and locals to make sure that the money is getting to those who need it most and in the most effective ways.

As part of our emergency response, we should address inefficiencies in areas that are most acutely impacted by the drought. For example, installing water meters will let people know how much water they’re using and help local water systems find leaks more quickly.

We also must accelerate long term solutions. We need to fundamentally shift how we’re delivering water to rural communities and look at ways we can build resiliency and get economies of scale. That means not having individual homes or small neighborhoods rely on a single well, which makes them incredibly vulnerable to any changes to that water supply. I think there’s a lot of promise with the way the state is looking at drinking water and pushing for consolidation and shared water supplies. More needs to be done to make sure there is diverse water supply in these areas.

The water bond brings a large chunk of capital and technical assistance; we need to invest it in solutions that are sustainable and affordable, and supply safe water to our most vulnerable even in future droughts.

Learn More

Watch a video of the panel discussion What If California’s Drought Continues? (August 2015)

New Water Laws Address Groundwater, Marijuana

As the California legislative session came to a close, Governor Brown signed more than 20 bills that address different aspects of water policy, ranging from water conservation and measurement to water quality. Two bill packages took important steps toward improving groundwater management and reducing the negative environmental impacts of marijuana farming.

New tools for groundwater management

Our recent report What if California’s Drought Continues? noted that improved management of our groundwater resources is critical to weathering droughts now and in the future. The 2014 Sustainable Groundwater Management Act (SGMA) seeks to ensure long-term viability and reduce over-pumping by setting deadlines for local agencies to develop and implement plans for basin sustainability. Before SGMA, groundwater users in some Southern California basins recognized the need to balance their groundwater use and went through a legal process called adjudication, in which courts determine individual rights to groundwater and appoint an entity to oversee its use. By clarifying pumping rights, adjudication makes it much easier to manage basins. But the time and cost of some adjudications have discouraged the use of this tool in other regions. Two new bills will make adjudication more suitable for managing the state’s groundwater resources:

  • AB 1390 streamlines adjudication by expediting the identification of groundwater use in a basin, giving courts new power to quickly resolve disputes among pumpers, and other procedural improvements. The goal of the bill is to create a more affordable, easier, and faster adjudication process that is applicable to any groundwater basin in the state.
  • SB 226 is designed to ensure that streamlined adjudication doesn’t conflict with SGMA by requiring severely over-drafted basins to comply with its provisions and deadlines regardless of ongoing adjudication actions. The bill also is intended to provide guidance for courts to align adjudications with SGMA requirements such as groundwater sustainability plans and groundwater sustainability agencies.

Marijuana regulation

Another challenge highlighted by the current drought is the impact of marijuana cultivation on our water resources and environment. The State Water Resources Control Board and the Department of Fish and Wildlife (DFW) are running a joint pilot project to address these issues in the North Coast region. The Cannabis Pilot Project evaluates potential policy solutions for reducing the environmental impact of cultivation practices and managing illegal use of stream water for irrigation. The medical marijuana bill package —AB 243, AB 266, and SB 643—creates a foundation for making this pilot permanent and building a statewide program to regulate the impact of marijuana on water and the environment.

For example, AB 243 and SB 643 direct the Water Board and DFW to take statewide regulatory actions that protect instream fish spawning, migration, and rearing from the damaging impacts of marijuana cultivation.

Questions remain about how to fund this new effort, however. The Cannabis Pilot Project is funded for just three years, and covers just a small portion of the state. Additional funding will be required to expand regulations to cover California’s estimated 50,000 marijuana growers. AB 243 proposes a $10 million loan from the state’s general fund to jumpstart the new Bureau of Medical Marijuana Regulation in the Department of Consumer Affairs, but these funds will not support the environmental programs run by the Water Board and DFW. A fee on all marijuana cultivators is the best way to fund these programs over the long term, and the Water Board has authority to establish such fees.

Learn More:

Visit the PPIC Water Policy Center drought resource page

Stressful Times for Drought-Stricken Delta

The Sacramento–San Joaquin Delta is one of the West’s most important estuaries, and a critically important water source for millions of Californians. But decades of water exports and human alterations have transformed this aquatic ecosystem, and a few dozen of its native species have dwindled to the point of extinction. We interviewed Phil Isenberg, vice chair of the Delta Stewardship Council and a member of PPIC’s board of directors, about the state of the Delta.

PPIC: How is the Delta faring these days?

Phil Isenberg: From an environmental perspective there’s not a lot of good news. The Delta is a severely damaged environmental site of great importance, and the damage has continued for more than 100 years. Very little restoration activity has taken place compared to the vast development of water supply infrastructure that has gone on in the past century. More housing is being built in flood-threatened areas, and urban growth continues on the boundaries. Some areas like Stockton are rapidly encroaching on agricultural and environmentally sensitive areas in Delta. The state’s Delta tunnel proposal has a greatly reduced environmental restoration plan—only about 30,000 acres of land will be put in protected status or restored for environmental purposes. It’s not insignificant, but certainly not as positive as the 150,000 acres which was part of the Bay Delta Conservation Plan.

PPIC: What is the role of the Delta Stewardship Council in managing this important resource?

PI: Our mandate is to achieve two equally important goals: to provide a more reliable water supply for California, and to protect, restore, and enhance the Delta ecosystem. It’s the latest legislative attempt to create a legally enforceable governance and management plan for the Delta. The Delta Plan was adopted in 2013; within 30 days we were sued by 27 plaintiffs, ranging from agricultural interests, state and federal water contractors, the city of Stockton, and several environmental groups. Interestingly, no state agencies or counties have sued. Their legal argument seems to be either we went too far or didn’t go far enough—which suggests to me that we may have struck the right balance.

PPIC: What does the latest science tell us about the Delta’s condition?

PI: Besides being severely damaged by human actions over centuries, the Delta has also been damaged by the drought and by the diversion of water for human purposes during drought. Scientists are skeptical about the ability of government or society in general to be able to rapidly improve the environmental condition of the Delta. We have altered the ecosystem in too many ways. We’ve channelized its waters, put in more than a thousand miles of levees, allowed people to move into the floodplain, brought in invasive nonnative species, and allowed pollutants to flow in from industry and agriculture. The best science we’ve received over the years is that the Delta’s environmental troubles can be managed better, but we will not likely be able to save all species in face of these threats. The political process demands immediate action, but science tells us that it will take decades to improve a Delta damaged over the past 160 years. A big part of any real solution is to involve independent scientists in decision-making and then follow their advice.

PPIC: What’s the most difficult tradeoff we’re facing in the Delta?

PI: The biggest problem is the conflict between illusion and reality. Basically, the water supply in California has not expanded since we began keeping track in the late 1880s. Worse, the water supply remains highly volatile. As our society has grown, demands for water have increased; our demands now exceed available water in many years. People have unrealistic expectations that ignore the limits of our supply. Although it is state policy to reduce human reliance on the Delta—and to compensate for that with heavy investments in water conservation, recycling, and the like—a lot of folks want more.

PPIC: What’s your biggest hope or aspiration for the Delta’s future?

PI: The Delta is constantly changing; we can’t freeze it in time. The Delta that existed before extensive human changes cannot be recovered. California hasn’t always done the right thing regarding water, but over time we get it right more often than not. So I hold out a reasonable level of hope for an improved Delta in the future. A successful Delta future for me is one that stops urbanization and protects its environment and the agriculture that remains. Will it work? Ask me in 100 years.

Learn more: