Article Special Series Ellen Hanak

Delta Blues: What Troubles in the Delta Mean for California

Ellen Hanak is an associate director of research at the Public Policy Institute of California. Her recent report (co-authored by Jay Lund, William Fleenor, Richard Howitt, Jeffrey Mount and Peter Moyle), Envisioning Futures for the Sacramento-San Joaquin Delta, is available online at

On any given day, a visitor to California’s Sacramento-San Joaquin Delta might see acres of verdant cropland, meandering boaters, recreational anglers and some Swainson’s hawks or sandhill cranes. Being there, it’s hard to imagine that this peaceful region is in deep trouble and that its fate will have serious consequences for residents throughout the state.

Located east of the San Francisco Bay Area at the point where the Sacramento and San Joaquin Rivers flow together, the Delta is a vast network of water channels and manmade islands. The enormous difficulties facing this ostensibly serene region, while not entirely new, have reached crisis proportions. My recent co-authored report from the Public Policy Institute of California (PPIC), Envisioning Futures for the Sacramento-San Joaquin Delta, examines some long-term alternatives for Delta management and considers the implications Delta policy will have for the state’s rapidly growing communities.

Fragile Levees Threaten the State’s Water Supply

One of the Delta’s most immediate problems is the stability of the 1,100 miles of levees that protect low-lying Delta lands from flooding. Built mostly between the 1850s and the 1930s, these levees are increasingly at risk of failure. Rising sea levels and higher winter flood flows — both consequences of climate change — are putting even greater pressure on the levees. Farming fragile Delta soils compounds the problem because it causes the land behind the levees to sink. Many Delta islands lie more than 10 feet below sea level (see Figure 1). The Delta is also situated near numerous earthquake faults.

Taking all these risks into account, one recent study estimated that there is a two-thirds chance of catastrophic levee failure (multiple breaches on multiple islands) in the next 50 years.

Such a failure could cause massive flooding of Delta islands, drawing in large volumes of salt water from the San Francisco Bay. One consequence would be the shutdown of the large water pumps located near Tracy at the Delta’s southern edge, interrupting the supply of water to cities from Northern California to the Mexican border and to millions of acres of San Joaquin Valley farmland. Critical infrastructure that crisscrosses the Delta, such as roads, rail lines and pipelines, could also be disrupted. An analysis of one scenario (a 6.5 magnitude earthquake in the middle of the summer) found that it could take more than a year to get the pumps back online and estimated the cost to the state’s economy at $30 billion to $40 billion.

Printable PDF of Figure 1

Ecosystem Woes Take Center Stage

The Delta’s other major problem is the health of the many fish species that live there. Managing water supplies for human use is not always compatible with providing healthy conditions for key species. Since the early 1990s, considerable efforts have been devoted to addressing these tradeoffs, and improvements have been registered for Sacramento River salmon runs. However, in recent years the population of fish known as pelagic organisms (so named because they live in the open waters of the Delta) has plummeted (see Figure 2). One of these fish, the tiny Delta smelt, is protected under both the state and the federal Endangered Species Act.

An interagency scientific team tasked with investigating the crisis found multiple reasons for the decline of pelagic organisms. Non-native species have invaded the Delta and are competing for food and habitat, and harmful crop pesticides appear to be taking their toll. The management of the southern Delta pumps, which carry water to major cities across most of the state, also plays a role by interrupting natural flows and by drawing some fish to their death. Because of the Delta smelt’s protected status, state and federal operators of the pumps need special permission, or “incidental take” permits, to manage water flow in a manner that causes the fish harm.

Surveys conducted in spring 2007 found juvenile Delta smelt populations had declined even further to levels so low that extinction became a genuine fear. In June, to avoid killing smelt that were congregating near the pumps, managers of the State Water Project shut the pumps down for 10 days. Pumping has resumed, but at lower rates than usual. Furthermore, state and federal judges recently ruled that both the State Water Project and its federal counterpart, the Central Valley Project, need to do a better job of protecting the smelt if they want to continue exporting water from the Delta.

In short, the fragile Delta environment and levees have become threats to the state’s water supply.

Printable PDF of Figure 2

Charting a New Course

Some of these recent events have prompted a better understanding of the risks involved with the Delta and a flurry of policy actions. The state significantly increased the budget for levee repairs in 2006, and two bond measures passed in November 2006 allocating additional funds for flood control in the Delta. The state also launched the Delta Risk Management Study, a detailed assessment of the risks to the levees that will provide crucial input into investment decisions.

Meanwhile, several efforts are under way to develop new long-term management strategies for the Delta. Local water agencies, environmental groups, and the state and federal fisheries agencies have been working to create a Bay Delta Conservation Plan, with the goal of finding ways to support environmental objectives while improving water export reliability. Governor Schwarzenegger’s Delta Vision effort has an even broader objective: Develop a long-term vision for the full range of Delta services, including land use, transportation, recreation, water supply and a healthier ecosystem. These efforts have tight timelines, with preliminary recommendations due before the end of this year and fuller plans due in 2008.

Charting a new policy course for the Delta will be anything but easy. There are many competing objectives, and trade-offs will be unavoidable. But a new course is essential. Business as usual in the Delta threatens the very survival of native species, the health of a unique ecological resource, and the state’s water supply system and other key services.

Printable PDF of Figure 3

Long-Term Alternatives

In the Envisioning Futures report released by PPIC in February 2007, we concluded that current Delta policy — which relies on incremental improvements to the levee system and reservoir releases in dry months to keep the Delta fresh — is not sustainable in any sense to any stakeholder. In the report, we lay out nine potential, long-term alternatives for managing the Delta, including preliminary assessments of each one’s price tag and ability to meet environmental and water supply objectives.

In the end, we found that five of the nine alternatives merit further investigation. One alternative that was categorically unpromising was that of abandoning the Delta, due to the extremely high economic cost of ending water exports.

The alternatives that hold promise fall into one of two basic pathways. One breaks the water delivery system’s reliance on the levee network by building a water conveyance channel. This could take the form of a “peripheral canal” that moves some Sacramento River water around the Delta to the export pumps, or an “armored aqueduct” within the Delta itself. In one of these alternatives (see Figure 3), a peripheral canal would connect to the lower San Joaquin River instead of going directly to the pumps, thereby improving water quality and environmental conditions in the south Delta.

All the conveyance channel alternatives offer the potential for more flexible management of water in support of desirable fish species because water in the Delta would no longer need to be kept fresh at all times for the sake of the export pumps. Recent scientific analysis finds that a variable Delta, one where salinity levels and water flows fluctuate, is more likely to support native species and help them compete with invasive ones. These alternatives can also improve water supply reliability for those who depend on Delta exports.

The other potential course of action would continue to rely on Delta channels to move water to the pumps, but with pumping occurring only when there is abundant fresh water, typically in the winter and spring. This strategy also moves away from relying on the levee system because it would not be necessary to keep the Delta artificially fresh when river flows are low. It could also provide flexibility for environmental water management because conditions would be allowed to vary. However, water exports would be more variable and probably lower, on average, than with one of the conveyance alternatives.

Additional storage capacity near the Delta (something able to take in large volumes of fresh water when the export aqueducts are full) might be valuable with these alternatives. One version, the “Eco-Delta” (see Figure 4), is based on the idea that the Delta of the future could also benefit from different land uses, including eco-friendly agriculture.

But in all likelihood, a hybrid alternative, something that relies on a combination of key elements from various alternatives, may be the most realistic and promising path forward.

Printable PDF of Figure 4

Weighing Alternatives

To date, our Envisioning Futures report has played an influential role in policy discussions on the Delta’s long-term future. Some (notably Delta farming interests) dispute our conclusion that current Delta policy is unsustainable and have argued for large investments to shore up Delta levees. But many other important players are actively assessing the alternatives we found to be legitimately promising.

This includes the Bay Delta Conservation Plan, which is evaluating the potential for a range of alternatives to meet water and environmental goals. And SB 27, a two-year bill intended for discussion in 2008, calls on the administration to adopt one of the report’s promising alternatives or a hybrid version of it. Speaking at an event in Bakersfield in June 2007, Gov. Schwarzenegger weighed in with his preferred alternative, a peripheral canal, echoing the views of many water agency managers for whom reliability of the water supply system is a paramount concern.

But many questions need to be answered before implementing any alternative. In the case of a new conveyance channel, for instance, how much water could be diverted without harming the Delta environment? What kind of operating rules would best meet various objectives? Should changes be funded by user fee contributions, taxpayer dollars or both?

Just as crucial are the difficult political agreements that will need to be hammered out for any new Delta policy. It is unlikely that any Delta solution can satisfy all interests in terms of water and land use. In the Envisioning Futures report, we propose the use of mitigation funds to help ease transitions for stakeholders who cannot be directly satisfied. Among the key candidates would be some Delta farmers whose lands would become unprofitable to farm under most alternatives.

For a major change in Delta policy, such as the construction of new conveyance, politicians are also likely to seek voter approval. Here, California’s past experience should give us pause. When the idea of building a peripheral canal went before voters in 1982, large majorities of Northern and Central California voters rejected what was perceived as a water grab by Southern California. These apprehensions should not be ignored even though conditions today are different. For example, far more Californians, from nearly every part of the state, now depend on water passing through the Delta. The fragility of Delta levees is also a much greater concern today. Still, voters may also need to be convinced of the environmental benefits of a canal. Our analysis suggests that these benefits are potentially great but they depend heavily on the details.

What Do the Alternatives Mean for California’s Communities?

About one-third of all water supplies in both the Bay Area and Southern California move through the Delta pumps, and the share is growing for cities in the San Joaquin Valley. Some communities depend on the Delta for as much 100 percent of their water supply. For many areas that are facing the prospect of rapid population growth in the near future, having enough water is a major concern. How will different communities fare under different Delta solutions? And if water exports are reduced, will this limit the state’s ability to accommodate anticipated growth?

In the long run, new conveyance alternatives would provide the state with a more reliable water supply than the variable pumping alternatives. But we still consider both pathways promising, based in part on an economic analysis of the cost to water users in the year 2050, when the state will have millions of new residents. Reductions in water exports would hit San Joaquin Valley farmers hardest. On the other hand, a combination of modern water management strategies (conservation, use of recycled water, underground storage and purchasing some water from farms) would allow urban areas to handle the cutbacks. Urban water agencies are already actively pursuing these strategies as part of their long-term plans to accommodate population growth. Reduced Delta exports would require pushing the envelope, but it would not equal catastrophe.

In any case, a new Delta policy, whatever it is, could take a decade or more to implement. In the meantime, local agencies need to take steps to become more resilient so they can handle slowdowns or shutdowns such as the one that occurred this summer. For local interests, this means building more physical connections between neighboring water systems and working out emergency sharing agreements to take advantage of alternative supplies. It may also mean developing more local storage options. Both of these strategies have put Southern California communities in a much less vulnerable position than they would have been a decade ago — with the capacity to ride out a Delta shutdown of up to two years.

Growth in the Delta: A Special Challenge

Finally, population growth in the Delta region raises some worrisome prospects that must be addressed. Although most of the Delta’s 738,000 acres are still devoted to farming, the region is surrounded by three fast-growing population centers: the San Francisco Bay Area, the Sacramento metropolitan area and the northern San Joaquin Valley. Growing proximity to jobs, transportation and inexpensive land is increasing pressure to urbanize parts of the Delta.

As many as 130,000 new homes are now in the planning stages within the Delta’s “secondary zone,” the area around the fringes where development is not restricted (see Figure 1 on page 30). Some of these homes would be located on land lying below sea level or in the direct path of flood flows. And, unfortunately, current fragmentation of land use authorities in the Delta leads to piecemeal decision-making that compounds flood risks, irreversibly destroys valuable wildlife habitat and causes water quality to deteriorate. The one coordinating group, the Delta Protection Commission, has only limited authority to regulate development in the central or “primary zone.”

The Delta desperately needs a strong regional permitting authority — something along the lines of the San Francisco Bay Conservation and Development Commission or the California Coastal Commission — that has jurisdiction over the entire region. Careful regulation should make it possible to both provide sufficient flood protection for developing areas and prevent urbanization from unreasonably interfering with the Delta’s environmental functions.

Solving the Delta crisis should be one of California government’s top priorities. It’s a monumental challenge but one today’s leaders should meet head on.

A Comprehensive Delta Report

In Envisioning Futures for the Sacramento-San Joaquin Delta (published by the Public Policy Institute of California), Research Fellow Ellen Hanak and an interdisciplinary team of experts from the University of California, Davis (Jay Lund, William Fleenor, Richard Howitt, Jeffrey Mount and Peter Moyle), present a wide-ranging analysis of the issues currently facing the Delta. The report explores and compares long-term Delta solutions, such as fortifying the levee system, sidestepping the Delta with a peripheral canal and allowing only seasonal water exports. Because no alternative is ideal from all perspectives, the report also considers a number of mitigation possibilities for those who are negatively affected by proposed changes in Delta management. In addition, the report includes detailed historical, ecological and economic analyses, drawing lessons from the Delta’s past and looking to its future.

The full report and an eight-page summary are available for free download at

This article appears in the October 2007 issue of Western City
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