To consolidate, disseminate, and gather information concerning the 710 expansion into our San Rafael neighborhood and into our surrounding neighborhoods. If you have an item that you would like posted on this blog, please e-mail the item to Peggy Drouet at pdrouet@earthlink.net

Thursday, October 24, 2013

Report: Devil’s Gate Dam cleanup will generate hundreds of truck trips, air pollution


By Steve Scauzillo, October 24, 2013


 The Devil’s Gate reservoir basin including the Devil’s Gate Dam and Hahamonga Watershed Natural Park in Pasadena, Monday, Sept. 14, 2009.

PASADENA >> A long-awaited environmental review of the Devil’s Gate Dam project released Thursday estimates the removal of between 2.4 million and 4 million cubic yards of backed-up sediment will require a maximum of 400 truck trips per day for five years.

The draft environmental impact report for the Devil’s Gate Dam sediment removal project says the project, which may begin in 2015, will pollute the local air, cause aesthetic impacts and add to traffic — impacts listed as “unavoidable.”

However, the 675-page EIR released by the Los Angeles County Department of Public Works also says the $70 million project will not have any significant environmental impacts in 14 other areas, including the habitat behind the dam that is home to birds, bats and amphibians.

Pasadena environmental groups and residents have opposed the sediment-removal plan, saying the mule fat and willow ecosystem that has sprung up as a result of debris flows since the last dredging project in 1994 serves as a natural part of the Hahamongna Watershed Park enjoyed by joggers, walkers, hikers and birders.

 Although county engineers say they are proposing an alternative that would leave an island of natural area but clear out additional edges for more effective flows, the early reviews of the complicated report reflect deep concerns.

“This is not a good plan for the environment nor for the birds,” said Laura Garrett, conservation chairwoman for Pasadena Audubon. Garrett had attended numerous scoping meetings in 2011 with the county and asked that some of the area be left with water for birds and wildlife to thrive.

“Instead, there will be between 50 and 60 acres that they want to keep permanently clear cut. You would only have rodents and lizards there. This is a much more severe plan than we saw during the public scoping time.”

After the 2009 Station Fire burned 160,000 acres of Arroyo Seco watershed, more than 1 million cubic yards of debris came to rest at Devil’s Gate Dam.

To some, the debris launched a verdant plant ecosystem and attracted a nesting pair of least bell’s vireo, a bird listed as a national endangered species, as well as state listed species including the western pond turtle and the coast range newt, according to the report.

But county engineers say the project is a matter of public safety. They say the debris flow may clog the valves and gates of the dam, rendering it unable to protect the downstream communities of Pasadena, South Pasadena, Highland Park, Hermon, Montecito Heights, Mount Washington and Cypress Park, as well as the 110 Parkway and the Rose Bowl during a 50-year storm.

“If we had a big storm event we would have some flooding down in the Arroyo Seco,” said Keith Lilley, principal engineer on the project with the county DPW.

County workers have removed small amounts of sediment each year since 2010 to keep the dam operating, he said.

The amount of debris to be removed will be at least 2.9 million cubic yards, or more, depending on debris amounts from future storms, Lilley said. The amount of debris will equal millions of tons, he said.

“In order to remove the sediment from the reservoir, trees and vegetation growing within the excavation areas will need to be removed,” according to the EIR.

Most of the time, the area behind the dam will be scraped by bulldozers and debris will be loaded onto double-dump trucks that will travel to three sites: the Waste Management facility in Azusa, the Vulcan Materials Reliance facility in Irwindale or the Manning Pit near Vincent Avenue and Arrow Highway in Irwindale, the report stated.

The trucks will also remove sediment temporarily stored behind Hahamongna Park at a defunct spreading ground.

The county is hosting three meetings on the project: 6-8 p.m. Nov. 6 at the Rose Bowl Stadium Visitors’ Locker Room, 1001 Rose Bowl Drive, Pasadena (enter at Gate A, Park in Lot F); 6:30-8:30 p.m. Nov. 14 at Jackson Elementary School Auditorium, 593 West Woodbury Road, Altadena; and 2-4 p.m. Nov. 16 at Community Center of La Cañada Flintridge, 4469 Chevy Chase Drive.

The comment period has been extended until Jan. 6. Send email comments to reservoircleanouts@dpw.lacounty.gov.

To view the EIR online, go to www.LASedimentManagement.com/DevilsGate.