Work starts on evacuation plans in case of Isabella Dam failure

Work starts on evacuation plans in case of Isabella Dam failure
Where would you go if there was a failure at the Isabella Dam? This week experts started work to draw up evacuation plans -- just in case.

In March 2006 Eyewitness News was first to uncover new concerns raised about safety issues at the two earth-filled dams. On Tuesday, a team of emergency response experts toured the dams to get a first-hand look at the conditions.

The consultant team, Robert Olson and Associates, is being paid $244-thousand dollars for the evacuation planning. Kern County Emergency Services Manager Georgianna Armstrong tells Eyewitness News the money comes from a grant.

The consultant's team of experts pulled up to the Auxiliary Dam in a big Sheriff's bus. They walked along the top of the dam, escorted by several Corps of Engineers spokesmen and dam operators.

Consultant Bob Olson was impressed with the size of the lake behind the two dams. "As you know, we're at the beginning of developing this evacuation plan -- and this is a very serious situation," said Olson. He looked over the lake, saying that's a lot of water that would be released if there's a problem.

The water in the lake has been lowered as a precaution after the new concerns were discovered. The studies in 2006 identified more "seepage" than thought. That's when water soaks under or through a dam.

New analysis also found concerns with the size of the spillway in the Main Dam, and new studies found previously unknown earthquake faults running under and near the dams.

The earth-filled structures were built in 1953 for flood control and water management.

Eyewitness News found "inundation maps" showing water would flood a wide area in and around Bakersfield if the dams suffered a total failure when the lake was full. In a worst case situation, water would be 8 feet deep in central Bakersfield. The maps are from very old data.

While the Corps studies how to fix the dam, the County wants emergency response plans in place.

The evacuation experts took photos and notes as they looked over the dam. They also had lots of questions for the spokesmen from the Corps.

"We need to explore further with the Corps of Engineers the nature of their communication and decision-making process," says Olson. He wants to know how the Corps will watch for signs of any problems, how they would tell emergency crews, and how fast.

The evacuation experts were also impressed with the Kern River as they rode up the canyon. That's where the water would go, if the dam failed. Olson spotted other conditions that need to be considered.

"I was impressed with how steep it was," says Olson of the canyon. "The slopes -- if there's earthquake shaking -- look like they could really result in some rock falls and other things which compound the problem."

The evacuation experts spent two days in meetings with various "first responders" -- the County Sheriff's Department, Bakersfield Police, and city and county fire departments. Those agencies will help, if there's an emergency -- and they will be involved in drawing up the evacuation plan.

A couple more developments should also shape up in the coming weeks. County Emergency planners will meet next week with Corps of Engineer officials to get the most up-to-date information on where water would go if there's a dam failure. The county says they need new and accurate "inundation" information to draw up evacuation plans.

And, as Eyewitness News has reported -- there are plans to install two warning sirens near the community of Lake Isabella. Kern County Fire Department officials expect more progress on this project in several weeks.

As for the evacuation plan, Kern Emergency Manager Georgianna Armstrong says the consultants working on the project are the best experts in the field. They expect to have an emergency response plan finished by November, but hope to have information on evacuation routes ready before that.

Bob Olson says it's a contingency plan, "Getting people out of harm's way the most effective way we can, as fast as we can."