Let’s Dam Up This Out-of-Date Plan : Flood-control project for the Sacramento region is unneeded and too costly

In the old days of California water policy, an important article of faith was that any dam was better than no dam at all. Egged on by some members of Congress, the Army Corps of Engineers is trying to revive that spirit with plans for a new dam in the Sierra foothills northeast of Sacramento, near the town of Auburn.

This would not be the massive, $3-billion Auburn plan that the corps abandoned some years ago. It would be a more modest flood-control model costing something less than $1 billion. But it’s still too ambitious for these days of tighter state and federal budgets--and smarter water policy.

Some Sacramentans like the dam proposal because they remember 1986, when officials were mere hours from evacuating parts of the capital because flooding seemed imminent. But there are other, more environmentally benign and less expensive ways to protect Sacramento. Besides, even though the federal government would pay for 75% of the project, the state may be too broke for years to scrape together the rest.

Sacramento’s head is turned mostly by an abstraction in which the corps offers protection against flooding of a severity that would occur every 200 years instead of once every 150 years, a more likely figure. The corps should be forced to look harder for ways to protect Sacramento from floodwaters.

One viable alternative is to make better use of Folsom Dam, a few miles southwest of Auburn, for flood control. The Environmental Defense Fund (EDF) says that Sacramento would have protection from 100-year floods if the corps does no more than operate Folsom--which was designed originally to control floods--just that way. Improvements to Folsom probably would provide protection against a 200-year flood at far less cost than a new dam, the EDF says.

Sacramento may have had the close call it did in 1986 because the corps had hoarded water for several days to build up supplies for farms and cities against a gathering drought. In contrast, the dam’s design and the corps’ own operating manual for Folsom called for releasing water gradually to keep the reservoir low enough to hold back any floodwaters.

If this procedure were followed as a matter of course, the gradually released water could be stored behind levees on islands in the delta below Folsom Dam. One group proposes to do just that, selling the water during dry months and letting the islands revert to wetlands for waterfowl.

The corps should take a hard look at this and other, better ways of storing water before it reverts to the Dark Ages with another costly dam.