A team of experts says the best way to fix California's troubled water system is to build a peripheral canal that would deliver water around the Delta rather than through it.
The report concludes that a canal would be the cheapest economic alternative and the best choice for the environment short of cutting off Delta water shipments to the Bay Area, San Joaquin Valley and Southern California.
"Ultimately, there are two choices here: no exports or a peripheral canal. If there are no exports, the biggest losers are the Bay Area (residents)," said Jay Lund, a UC Davis engineering professor and one of the report's co-authors.
The report was conducted by the nonpartisan Public Policy Institute of California and written by several leading Delta experts, mostly at UC Davis.
In essence, the report finds that the Delta, the weak link in a system that delivers water to millions of acres of farmland and two-thirds of California's residents, will inevitably succumb to rising sea level or earthquakes.
And, the report notes, the current method of taking water with giant pumps in the south Delta is already wreaking havoc on protected fish populations to the point that water managers are being forced under court order to curtail water deliveries.
In response, the state should build a canal now to shield the economy from the effects of a major failure.
Big water agencies enthusiastically welcomed the report while others, including the Contra Costa Water District, were skeptical.
"It makes some fundamental mistakes with ivory tower assumptions," said Contra Costa Water District assistant general manager Greg Gartrell.
The report, Gartrell said, writes off Delta farmers who could be forced out of business and assumes that the state's biggest water users would be willing to pay $5 billion to $10 billion or more for a canal that at least one study has shown could not deliver the same amount of Delta water that they have been getting in recent years.
But the biggest flaw, according to Gartrell, is that the study assumes regulations, laws or public agencies will be able to limit the flow of water through a large canal. If too much water is taken through a canal, it could increase the concentration of salts, pesticides and other pollution in the Delta and possibly damage salmon populations.
Rather than building a small canal that could have no more than a minimal effect on the flow of fresh water into the Delta, the team recommends a large one be built to ensure it can take a lot of water at appropriate times.
But how to ensure that the canal is not overused to the detriment of the Delta water quality and water supplies in the northern part of the state?
"(There's a) lack of trust, and for good reason," Gartrell said.
The report mostly dismissed a hybrid option, which has gained a lot of support recently, of using a small canal in combination with channels that now deliver water through the Delta. The state should recognize that existing channels would eventually fail due to the sea level rising and the possibility of a major earthquake.
"That's another reason not to build the canal too small," said Ellen Hanak, a Public Policy Institute of California economist and co-author.
Environmentalists were also cautious.
"Whether or not a peripheral canal is determined to be the preferred solution remains to be seen after it undergoes thorough scientific scrutiny and evaluation," said Ann Hayden, a water policy analyst at the Environmental Defense Fund, adding that the key is for more fresh water to flow through the Delta.
Voters rejected a canal in 1982 because of overwhelming opposition in the Bay Area and the rest of Northern California.
Residents in Contra Costa County and elsewhere near the Delta were concerned that by taking more freshwater out of the Delta, the canal would make the Delta saltier and more polluted.
Now, however, large populations in the East Bay and South Bay are more dependent on the Delta water system, leading canal supporters to conclude it will be more politically viable today than it was a quarter-century ago.
Hanak said the cost to the state of phasing out the use of Delta water across California would range between $1.5 billion and $2.5 billion a year, less than 1 percent of the state's gross domestic product.
"It (eliminating water deliveries from the Delta) is not going to destroy the California economy," she said, adding that the impact would be severe for San Joaquin Valley agriculture.
"It's much more expensive than the other options," she added.
Delta smelt would stand a 60 percent chance of survival if Delta water deliveries were halted, a 40 percent chance with a peripheral canal and about a 30 percent chance if no changes are made, the report said.
A viable commercial salmon fishery in California is about 80 percent assured without Delta water exports, about 50 percent with a canal and about 30 percent under the status quo, it said.
The report, "Comparing Futures for the Sacramento-San Joaquin Delta," was written by Lund, Hanak, engineer William Fleenor, biologist William Bennett, economist Richard Howitt, geologist Jeffrey Mount and biologist Peter Moyle.