Report Lays Out Options for Delta, Including Peripheral Canal

By Mike Taugher, Contra Costa Times, Walnut Creek, Calif.

Feb. 7–California must either dramatically reduce its use of Delta water or build something akin to the peripheral canal, the highly controversial proposal to allow parts of the Bay Area, San Joaquin Valley and Southern California to tap directly into the Sacramento River, according to a major new study released today.

The report also says that decades of policies designed to keep the Delta’s water fresh are wrongheaded, in effect putting the drinking water supply of 500,000 Contra Costa residents in direct conflict with the needs of a dying ecosystem.

Salinity in the Delta historically fluctuated from salty to fresh, depending on the season and the amount of rain and snow that fell, the study said. Restoring the ecosystem would require bringing back fluctuating salt levels, which is impossible now because it would ruin drinking water supplies for 23 million people and irrigation water for millions of acres of farmland.

But the Contra Costa Water District contends the researchers are wrong about historic salinity levels in the Delta, and district assistant general manager Greg Gartrell said records show fresh water existed year-round in the Antioch area until upstream diversions to farms and other uses, followed by dams, deprived the Delta of fresh water and allowed more salt to intrude.

Still, there is no disagreement that the Delta is in crisis.

The Delta, arguably this arid state’s most important source of water, could physically collapse because of fragile levees that are under increasing pressure from land subsidence, sea level rise and the possibility of a major earthquake. It is already in a deep ecological crisis because of plummeting fish populations. And government programs to manage the Delta have lost the confidence of most people.

“The Delta is facing a crisis that will affect the entire state,” said Ellen Hanak, a research economist at the Public Policy Institute of California.

The report, published by PPIC and written by Hanak and a team of five experts from UC Davis, examined nine different ways the Delta might be managed and rejected four of those options.

The five alternatives it said should be further studied include:

— A modernized Peripheral Canal that would be smaller than the one rejected by voters a quarter-century ago. This would allow more flexible management of the Delta with greater fluctuation in salinity levels, which supporters said could benefit fish.

— A South Delta Restoration Aqueduct, almost identical to the peripheral canal except that it would deliver water to the lower San Joaquin River, which would flush out the South Delta — a region plagued by poor water quality and low water levels — before that water is transported to other users.

— An “armored-island aqueduct” that would perform essentially the same functions as the peripheral canal except that water would be transported through the Delta in a series of widened channels and fortified levees. Bringing water through the Delta might be less controversial, but it also poses problems for migrating salmon.

— An “opportunistic” pumping regime that would allow water to be pumped out of the Delta only when flows are very high during winter and spring. Delta water supplies would become highly variable and would probably range from 2 million acre-feet to 8 million acre-feet a year, in contrast to the more than 6 million acre-feet now pumped each year.

— An Eco-Delta that would be managed primarily for environmental purposes, with water deliveries and other uses secondary. Water availability would be much less; the report estimates 1 million acre-feet to 5 million acre-feet a year.

The report rejected letting nature take its course in the Delta, or trying to manage the Delta much as it is today. It also rejected fortifying levees to ensure the safety of water supplies or building a giant dam — even a potentially moveable dam — as too costly or environmentally poor alternatives.

As a result, the report essentially recommends Californians either reduce water use out of the Delta, perhaps dramatically, or revisit one of its most bitter political fights: the referendum on the Peripheral Canal that killed the project in 1982.

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Copyright (c) 2007, Contra Costa Times, Walnut Creek, Calif.

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