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Press Release · July 17, 2008

Peripheral Canal Is Best Strategy To Save Delta Ecosystem, Ensure Reliable Water Supply

State Leaders Urged to Chart Sustainable Future for Ailing Region

SAN FRANCISCO, California, July 17, 2008 — Building a peripheral canal to carry water around the Sacramento-San Joaquin Delta is the most promising strategy to balance two critical policy goals: reviving a threatened ecosystem and ensuring a high-quality water supply for California’s residents. That is the central conclusion of a report released today by the Public Policy Institute of California (PPIC).

Under current policy, water is drawn from the Sacramento River and sent south through the Delta to enormous pumps that deliver water to millions of households in the Bay Area and Southern California and millions of acres of Central Valley farmland. This approach, which disrupts the natural water flow, has threatened native fish and made the Delta attractive to invasive species. Furthermore, it is unsustainable. Projected sea level rise, crumbling ancient levees, larger floods, and high earthquake potential will inevitably result in a dramatically different Delta environment. This environment will have saltier water, which will be much more costly to treat for drinking and ultimately unusable for irrigation, the report says.

Although it would be best for fish populations if California stopped using the Delta as a water source altogether, this would be an extremely costly strategy, according to the report, authored by a multidisciplinary team including Ellen Hanak, PPIC associate director and senior fellow, and Jay Lund, William Fleenor, William Bennett, Richard Howitt, Jeffrey Mount, and Peter Moyle from the University of California, Davis.

The PPIC-UC Davis team concludes that a peripheral canal is not only more promising than the temporary and ultimately unsustainable “dual conveyance” option – which combines the current approach with a canal – but is also the best available strategy to balance two equally important objectives.

“Coupling a peripheral canal – the least expensive option – with investment in the Delta ecosystem can promote both environmental sustainability and a reliable water supply,” Hanak says.

The new report, Comparing Futures for the Sacramento-San Joaquin Delta, builds on the findings of a 2007 PPIC study by the same team, which concluded that the need for a new Delta strategy is urgent. The new report was funded in part by Stephen D. Bechtel Jr. and the David and Lucile Packard Foundation. Among its recommendations:

  • Plan to allow some Delta islands to flood permanently. The state should invest in the levees that protect high-value land, ecosystem goals, and critical infrastructure – and allow lower-value islands to return to aquatic habitat.
  • Begin the transition from the current Delta management system. The current system is harming the native fish now, as federal court rulings have found. Over time, it will hurt the state’s economy. Natural forces will impose change on the current system, and planning for change now will make Californians less susceptible to the potentially much larger cost of earthquake, floods, or levee failures.
  • Develop a new framework for governing and regulating the Delta. With the proper safeguards, a peripheral canal can be economically and environmentally beneficial. It is a more cost-effective strategy than dual conveyance, which, because it relies on continued pumping through the Delta, is an interim solution.

“Choosing a water strategy is just the first step,” UC Davis researcher Lund says. “The technical, financial, and regulatory decisions necessary to plan for a new Delta are enormous. The governor and legislature need to be involved in setting up a new framework to manage the challenge.”


The Public Policy Institute of California is a private, nonprofit organization dedicated to informing and improving public policy in California through independent, objective, nonpartisan research on major economic, social, and political issues. The institute was established in 1994 with an endowment from William R. Hewlett. PPIC does not take or support positions on any ballot measure or on any local, state, or federal legislation, nor does it endorse, support, or oppose any political parties or candidates for public office.