[Water_news] 1. DWR'S CALIFORNIA WATER NEWS - Top Item for 11/20/07

Department of Water Resources

California Water News

A daily compilation for DWR personnel of significant news articles and comment

 

November 20, 2007

 

1.  Top Item

 

Quake study paints dire picture of Delta

KGO-TV/DT Channel 7 (Bay Area) – 11/19/07

By Laura Anthony, reporter

 

Nov. 19, 2007 (KGO) - Governor Schwarzenegger is among a growing number of people who believe the threat of a major earthquake is the main reason the California levee system is in desperate need of a multi-billion dollar overhaul. However, others claim the threat of a big quake in the Delta is dramatically over-stated, despite what scientists and history say. A controversial study paints a dire picture for the Delta, if, and when, the big one hits.

 

In New Orleans, it was a tremendous hurricane that caused the levees to fail, prompting massive, deadly, flooding. In the Bay Area there are no hurricanes, but there are earthquakes, and most experts agree that a very big one is very long overdue.

 

"Nobody, I believe, doubts that the earthquake is on the horizon. It's just a question of when," says Dr. Les Harder, deputy director for the California Department of Water Resources.

 

The California Department of Water Resources is the agency currently studying exactly what might happen to the levee system if a 6.5 quake hits east of San Francisco.

 

"If that happened, not only would this be devastating to California -- all of California -- but it would be a national issue," says Dr. Harder.

 

According to DWR's Delta Risk Management Strategy, minutes after a large quake hits, dozens, if not hundreds of levees could fail, flooding thousands of acres of farm and residential land.

 

Within hours, as many as 30 Delta islands could liquefy or flood, like Bradford, Twitchell and Sherman islands, endangering more than 9,000 residents and prompting the contamination of drinking water for 23 million Californians for months, even years.

 

"When you flood an island below sea level, it sucks all this water, and if that happens during the dry season, it will basically draw water in from San Francisco Bay back east toward the Delta and make the water in the delta salty," says Dr. Harder.

 

According to the study, in the Delta alone, a large Bay Area earthquake could cost California more than $400 billion dollars in economic losses and irreparable damage to a fragile ecosystem.

 

U.C. Berkeley engineering professor, Raymond Seed, sits on a government committee reviewing the Delta Management Risk Strategy.

 

"A 6.5 on the Hayward fault would probably not be very damaging for the Delta. A 6.5 on the Calaveras fault would be far more damaging and a 6.5 beneath the western end of the Delta, where there are systems that could do that, would be hugely destructive," says Professor Seed.

 

That's why levee experts, Governor Arnold Schwarzenegger and many lawmakers are pushing for a massive retrofit of the levee system. But not everyone's convinced that a major earthquake here in the Bay Area would be devastating to the Delta.

 

"Historically, it's unlikely. Looking forward I suppose it's a possibility," says Tom Zuckerman, a Delta landowner.

 

Tom Zuckerman is not a scientist, but he is a major landowner in the Delta, a lawyer, and serves on various local committees that study levee issues.

 

"I think they're concentrating a little too much on this apocalypse scenario, instead of looking at the more garden variety, ordinary flood problems we're likely to have any year," says Zuckerman.

 

Zuckerman believes the strategies already in place for strengthening levees are mostly adequate. However, others say to deny the potential impacts of a major earthquake is to imperil an entire populace and one of the world's largest economies that is California. It's also a position that ignores the odds.

 

"The Delta Risk Management studies suggest that once every 100 to 200 years, on the average, you would expect to get an event that would be devastating to the Delta. We haven't had one of those for 140 years now," says Professor Seed.

 

The Delta Risk Management Strategy is currently in draft form and under review by a committee of scientists and engineers. It will be highly scrutinized and likely revised before its expected final release next year. #

http://abclocal.go.com/kgo/story?section=assignment_7&id=5771546

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