Pasadena Officials Express Concern Over Devil's Gate Proposal

The Pasadena City Council Monday night voted to send a letter to county officials expressing concern over a county plan to remove millions of tons of sediment from Devil's Gate Dam reservoir in the Hahamongna Watershed Park.

The letter will urge Los Angeles County officials to study the needs of the Devil's Gate Sediment Removal and Management Plan in greater detail, adopt a plan that mirrors the Hahamongna Watershed Park Master Plan and involve the city on a staff level in the project's design and engineering aspects, officials said.

Over 100 comments from at least eight Pasadena departments expressed concern regarding all aspects of the county's Draft Environmental Impact Report.

Pasadena's Environmental Advisory Commission also suggested officials seek the least harmful sediment mitigation plan. Concerns over increases to air and noise pollution, traffic and permanent loss of critical habitat were also expressed.

"The more significant challenge that the city of Pasadena has … relate to the aspirations we have for this wonderful, natural area," said Pasadena Mayor Bill Bogaard. The mayor also noted that time is of the essence to deliver adequate comments by the county's Jan. 6 deadline.

Pasadena owns the land at the center of the debate and operates the Hahamongna Water Shed Park. The Los Angeles County Flood Control District maintains a perpetual easement to maintain the area, officials said.

Officials believe the county would overburden areas outside of its easement.

The proposed project would remove anywhere from 2.95 to 4 million cubic yards of sediment, over an area of 120.42 acres for a period of up to five years, according to the project's Draft Environmental Impact Report.

Pasadena's Environmental Advisory Commission found the county's DEIR to be replete with flaws and that it offers "no scientific rationale" to the necessity to remove the sediment or why exactly it needs to be done in the five-year timeframe.

Victor Gordo, Pasadena council member, said the county failed to properly maintain the reservoir over time.

"The last time anything was removed was 1994. The Station Fire only deposited 1 million cubic yards of sediment and now they're proposing the removal of up to 4 million. That tells me you haven't been maintaining this reservoir," Gordo said.

1.3 million cubic yards of sediment was deposited over the years as a result of the Station Fire in 2009, the largest fire in the Angeles National Forest, which scorched over 160,000 acres. The storms that followed deposited sediment into the Devil's Gate Reservoir.

County officials contest that sediment and plant removal is necessary to the Arroyo Seco flood control system, reporting that the reservoir no longer has the capacity to contain another large debris flow in the event of a large storm.

The project, if approved, would begin in 2015.

Many area residents have spoken out against the project since the DEIR was revealed in late October.

The area is home to mature willow trees, Mule Fat Scrub, Riversidean Alluvial Fan Sage Scrub and riparian vegetation, which would be destroyed if the plan was carried out, officials said.

The heavy machinery planned for excavation includes, but is not limited to, four front loaders, two bulldozers, one excavator, one grader, one water truck, and two tender trucks, according to the DEIR.

Double dump trucks would haul away the sediment and plant debris and would make an estimated 50 truck round trips an hour, equalling about 425 round trips per day, officials said.

All that machinery, opponents say, would generate traffic congestion, noise and air pollution.

The excavated sediment would be trucked and dumped offsite. Primary disposal sites being considered include the Waste Management Facility in Azusa, the Vulcan Materials Reliance Facility in Azusa, or the Manning Pit Sediment Placement Site in Irwindale. Secondary sites are being considered in Sun Valley, officials said.

Excavation would take place during the dry months.

Pasadena officials plan to retain a hydrology expert to perform an independent technical review of the county's project, said Loren Pluth, Department of Public Works Project Manager for Pasadena.

Staff may also establish the creation of a Devil's Gate Dam Sediment Removal working group, comprised of city staff and key community members to develop an alternative to the county's plan, Pluth said.

The Environmental Reporting Process is in the 75-day comment period process and is accepting comments by letter, email, or during public meetings. The deadline to submit comments is Jan. 6, 2014.

"We have a responsibility as the owners of the property to properly measure whether or not the county … is overburdening the easement and I think in this case there's clear evidence they intend to do that," Gordo said.

To view the Draft EIR, click the link.