The threat is well known. A big quake rumbles across the Sacramento-San Joaquin Delta, knocking out dozens of the primitive levees that guard the state's main water crossroads. A key source of water for nearly two out of three Californians and the nation's biggest fruit and vegetable garden is shut down for months, maybe even a year or two.
Can the state avert such a scenario?
The watery calamity that befell New Orleans has highlighted the sorry state of delta levees, prompting calls from Gov. Arnold Schwarzenegger and California congressional leaders for federal money for levee repairs.
The delta's vulnerabilities have also prompted some experts to dust off an idea they believe might be more practical: building a canal that would route water around the delta to agricultural and urban consumers in Central and Southern California. For though it may be technically possible to armor the delta, many experts doubt it is economically feasible.
Schwarzenegger last week asked the federal government for $90 million to improve some of the most critical levees in the delta and the Central Valley. But that is a fraction of the $1.3 billion in repairs officials say it will take just to bring the delta levee system up to basic standards. And that would do little to protect it from earthquake damage. The state Department of Water Resources can't even say how many billions more it would cost to do the seismic work.
"To make them basically earthquake-proof, you would probably have to start over with a brand-new levee system," said Les Harder, acting deputy director of the department and an engineer who helped put together a 2000 state analysis of the delta's seismic risk. "I think it's going to be unlikely we would ever make the whole delta today earthquake-proof."
That -- coupled with projections of rising sea levels that would stress the fragile levee system even without a major quake or flood -- is reviving talk of a politically charged alternative to delta water shipments: the Peripheral Canal. Rejected by California voters in 1982, the canal would have drawn water from the Sacramento River and carried it around the delta to federal and state aqueducts supplying the Central Valley and the Southland.
"The idea that you can fix this so that [massive earthquake failure] won't happen is nonsense," said B.J. Miller, an environmental engineering consultant who represents some of the Central Valley's largest irrigation districts. "You can't dig out the peat soil the levees are resting on. There is no economic way to do that.
