The U.S. Army Corps of Engineers from Sacramento is preparing to blast off on the Lake Isabella Dam Safety Project.
The water in Lake Isabella is currently held back by a main dam and an auxiliary dam, which together keep the cities of Lake Isabella and Bakersfield from flooding.
Now the state is planning to add a third dam, at 28 feet tall and 13-hundred feet long. They will also raise the existing dam 16 feet.
The purpose is to create an emergency spillway with ten times the capacity. The project was initiated after a study raised seismic and flood concerns with the current dams.
“Our worst case maximum flood would potentially overtop our dams by about nine feet. If that were to happen, we could have a catastrophic failure of the dams and send a breachway downstream to Bakersfield,” said Mike Ruthford, the project’s technical lead with the U.S. Army Corps of Engineers.
However, Ruthford says the chance of overtopping is one in 4,000.
“We want our project to do what it was authorized to do, and that’s to provide flood damage reduction benefits to mostly people downstream, especially the city of Bakersfield,” Ruthford said.
Blasting of the dam is scheduled to begin later in 2018, with a completion date of December 2022. This means side effects from the project will continue for about four years.
Project managers say drills may be audible, and blasts may create light tremors through the ground. These will be limited to weekdays only, and will not occur on holidays.
As for road closures, Highway 155 between Ponderosa Road and Pioneer Point will be closed two weekdays every week, for half an hour between 9 a.m. to 4 p.m. Many in the community are concerned about school bus traffic.
“So the afternoon buses may be an issue, but we plan to have our blasts roughly about midday, so that shouldn’t be an issue either,” said Toby Wallace, a blasting specialist with Flatiron-Dragados-Sukut, the contractor with the project.
The project will also clear parts of the lake while blasting, buoying off sections for safe boating and fishing. Wallace says no wildlife will be affected.
The project is federally funded with taxpayer money, costing a total of $650 million. Construction alone costs $240 million.