Plan Calls for Alarms to Warn of a Dam Collapse

Alarms will soon be installed to warn west Ventura residents of an imminent flood in the event an earthquake collapses the dam holding back Lake Casitas, under an emergency plan officials sketched out Thursday.

Eight sirens, similar to the ones that accompanied air raid drills during the Cold War, will be installed along an eight-mile stretch of Coyote Creek and the Ventura River--the path rampaging flood waters would follow from Casitas Springs to the ocean, according to officials for the U.S. Bureau of Reclamation.

The sirens are a sound residents hope they will never hear. If the alarm sounds, it means the dam has incurred a catastrophic collapse and a deadly flood is on the way.

It would mean a wall of mud and debris perhaps 80 feet high bearing down on 14,000 people living along the river. It would take about an hour to inundate much of downtown Ventura before the deluge reaches the coast. Only the swift and prepared will survive, officials warn.

“Everybody knows there is a big risk,” said Jay Bayman, program administrator for the county Office of Emergency Services. “It’s going to boil down to how fast can people move, how fast can you react to a siren, and how fast can you run. It could be controlled chaos.”

It is estimated 400 people would die under this worst-case scenario and property damage would be about $350 million, said William M. Pennington, a civil engineer for the Bureau of Reclamation.

Odds of such an event are remote, but serious enough to prompt local, state and federal emergency planners to meet Thursday in Ventura to begin planning their response.

A draft emergency plan, scheduled to be completed within 60 days, will identify areas of high ground people should seek to escape rising flood waters and suggest preparations residents should make to prepare for disaster. The plan will be submitted for public review before June.

Meanwhile, work crews have already surveyed the Ventura River channel in search of the best spots to locate sirens. Acoustic Technology Inc., the contractor selected by the federal agency, is expected to finish building the early warning system in early June.

But some residents are upset the government has waited so long to build a warning system. They say they do not have adequate time to comment on the system before it is installed and that important safety questions remain unresolved.

“People who live below the dam have lots of good ideas for evacuation and preparation, but they’ve been excluded,” said Pat Baggerly of the Environmental Coalition of Ventura County. “The public has been totally excluded from the evacuation planning process.”

Carin Kally of Ventura lives immediately below the dam. She says the dam is so fundamentally unsound that the alarm system should remain in operation after the dam is reinforced. Plans call for removing the sirens after work to strengthen the dam is completed in December 2000.

Officials dispute those assertions. They say they are working to include the public in their planning. A public meeting in Ventura on the warning system and dam improvement work is scheduled for April 19 at a site to be announced later. Additional public meetings are envisioned for spring and summer. More information is available via telephone at (805) 641-9494 and at a Web site, www:casitasdamsafety.net.

The Department of the Interior has made strengthening of 40-year-old Casitas Dam a top priority. Built largely on top of soft, sandy soils, federal officials say the dam is at high risk of failure in the event of a major quake.

Authorities plan to spend $42 million in the next two years to remove soft soils at the front of the dam and add tons of additional earth to buttress it.

During the work, officials say, the 335-foot-tall dam, already rated as particularly susceptible to collapse, will be further weakened, necessitating alarms in the event the dam is shaken apart before construction concludes.