High Tech Measures To Fix California's Levees

Aug. 28, 2007 (KGO) (KGO) -- This week marks the two year anniversary of Hurricane Katrina and the disastrous levee breaks that destroyed much of New Orleans and surrounding areas.

It's a threat that looms large in California, where experts say Sacramento and the California delta are still dangerously vulnerable to a massive levee failure.

Emergency repairs aside, the levees that protect Sacramento and the Central Valley remain among the most vulnerable in the country.

"Every time you live behind a levee, you're vulnerable. And there's always a risk behind a levee," said Meegan Nagy of the U.S. Army Corps of Engineers, Sacramento region.

According to the California Department of Water Resources, more than 1.8 million people now living in the Central Valley are protected by levees that in many places are more than a hundred years old.

"With every house that's added, there's an increase in risk," said Nagy.

The risk is more prominent if the levee is in disrepair. A new pilot study by the U.S. Army Corps of Engineers, on a one and a half mile stretch of a levee along the American River, found the structure "minimally acceptable."

The same test will be applied to hundreds of other levees. Starting next week, a torpedo-like electromagnetic device, suspended from a helicopter, will begin surveying 350 miles of urban levees in the Sacramento area.

"It's a means of looking into the foundation of levees, and through levees to evaluate the properties of the soils or geologic features below levees," said Mike Inamine, CA Dept. of Water Resources. "Certainly, it will [reveal weak spots]."

In the meantime, levee experts are now meeting in Sacramento. They're trying to figure out if a new policy from U.S. Army Corps of Engineers that tall vegetation be removed from levees across the country is a good policy for California.

The concern is by removing vegetation from levees, it would eliminate a habitat for some endangered species, making the fragile structure more attractive to burrowing animals like squirrels and gophers.

"I think we need more information and I think simple blanket approaches - remove all vegetation from all levees - is not the way to go," said Dr. Dirk Van Vuren, U.C. Davis Researcher.

Whatever methods eventually used to reinforce California's levees, the Army Corps estimates the cost could reach $40 billion.

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