L.A. County supervisors OK debris clearance for Devil’s Gate Dam

Despite strong opposition from neighbors and recreational enthusiasts, the Los Angeles County Board of Supervisors approved a five-year project Wednesday to remove debris from a basin above Devil’s Gate Dam in Pasadena.

Flood control officials have warned for years that sediment buildup in Hahamongna basin in northern Pasadena has reduced the dam’s ability to contain runoff from a major storm.

A huge amount of debris has accumulated in the basin as a result of the 2009 Station fire and subsequent storms. County officials and community groups have clashed over how to address the problem.

The Board of Supervisors agreed Wednesday on a plan to remove 2.4 million cubic yards of sediment from the basin. Officials say that the five-year project will reduce the risk of the dam overflowing and potentially flooding parts of the 110 Freeway and neighborhoods in Pasadena, South Pasadena and northeastern Los Angeles.

But Pasadena Mayor Bill Bogaard and others support an alternative plan that they say would provide the same benefits but require the removal of less sediment. Opponents of the plan approved by the supervisors told board members that hundreds of trucks would be required that would increase pollution and noise. They also say that the board’s plan will destroy the wildlife habitat in the basin and interfere with hikers, cyclists and horseback riders who use the area for recreation.

“This is nothing but a mining and trucking operation,” said Tim Brick, managing director of the nonprofit Arroyo Seco Foundation. He endorsed a proposal, backed by the Pasadena City Council, that would remove 1.4 million cubic yards of sediment over five years. That proposal also includes regular upkeep of the basin to maintain its capacity to catch debris.

He said the plan approved by the board Wednesday doesn’t solve the sediment problem, and will probably require another removal project in 20 years. His organization is considering various ways to stop the board-approved implementation, he said, including possible legal action.

“We’re not going to give up without a fight,” Brick said.

County officials said removing more sediment will reduce the flood risk for most major storms.

But Supervisor Zev Yaroslavsky, who cast the lone vote against the sediment removal plan, suggested that the alternative proposal might be sufficient to alleviate flood risks. He said the larger-scale operation to clean out the basin would involve 400 truck trips a day driving on the nearby roads. Pasadena residents were being generous when they asked for the number of trucks to be reduced to 300, he said.

“I’m not sure if I lived there I’d settle for 300 trucks a day,” he said.

Devil’s Gate Dam was built in 1920 to provide flood protection for the surrounding areas. County officials have been pushing to remove sediment from the basin for five years. Amid a slew of concerns from residents, the board ordered an environmental study of the plan before adopting it.

Supervisor Michael D. Antonovich, who represents the area and introduced the motion Wednesday, urged the board to approve the project, saying that action had been delayed too many times.

“No alternative is without its impacts,” he said.

soumya.karlamangla@latimes.com

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