Los Angeles

What About LA County's 14 Dams?

After NorCal's emergency spillway gave way partially to erosion, residents might be left wondering: What about Southern California?

In light of the emergency in Oroville that forced 200,000 to evacuate as the emergency spillway was under threat of collapse, the Los Angeles County Board of Supervisors is ordering safety inspections for all 14 dams in Southern California.

Devil's Gate is the oldest flood control dam run by Los Angeles County, built in 1920, and it can withstand a crest height of 97 feet. It's one of the 14 managed by the LA County Department of Public Works.

Officials said sediment stuck inside has lessened the amount of water it can hold. There is a solution in the works that's facing some legal action - and officials say it is just one of several fixes to dams like Devil's Gate that come with constant maintenance.

Bob Spencer of the Department of Public Works discussed the dam just off the 210 Freeway near NASA Jet Propulsion Laboratory.

"This dam is not in danger. We will not see anything like they have seen in Oroville but once Mother Nature is doing what she wants to do, the risk is always heightened," he said.

Risk of flooding could affect hundreds of homes along the Arroyo Seco. That is why Spencer said annual inspections and regular checks have led to fixes like new safety valves and floating booms to stop large debris.

"It creates an issue for us if those safety valves clog, because we need those to take the pressure off the dam face and make sure the reservoir doesn't spill," he said.

Some of LA County's 14 dams have had significant repairs. A seismic strengthening project is scheduled in the next year for the Santa Anita dam.

Spencer said some 2.4 million cubic yards of dirt needs to be removed from Devil's Gate - it's all remnants of storms following the Station Fire in 2009. That is reportedly enough sediment to fill the Rose Bowl three times over.

A clean-up plan from 2014 is also facing a legal challenge by environmental groups looking to minimize damage to wildlife.

"It's been a joint process organizing task forces and groups of stakeholders to enable us to reach a balance," Spencer said.

He said this is work that is long and involved and any upgrades need to go through much review.

County property owners in part pay for all the repairs and upkeep through a property tax assessment.

The Department of Public Works says it is a sustainable source of funding. In addition, the county also receives federal and state grants.

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