Devil’s Gate Dam ‘Big Dig’ Plans Denied

OUTLOOK photo For several years, concerned residents, such as those who gathered at a 2013 protest, have rallied against the county’s plan for removing millions of cubic yards of sediment from behind Devil’s Gate Dam. Opponents advocated for a more moderate plan.
OUTLOOK photo
For several years, concerned residents, such as those who gathered at a 2013 protest, have rallied against the county’s plan for removing millions of cubic yards of sediment from behind Devil’s Gate Dam. Opponents advocated for a more moderate plan.

A coalition of concerned residents last week cheered a judge’s order that, for now, has halted all activity related to the County Flood Control District’s plans aimed at removing 2.4-million cubic yards of sediment from behind the Devil’s Gate Dam.
“Judge James Chalfant’s ruling about the deficiencies in L.A. County’s Big Dig EIR for Hahamongna is a big victory,” the Arroyo Seco Foundation proclaimed on its website.
In a lawsuit, the Arroyo Seco Foundation and the Pasadena Audubon Society argued that the “big dig” would harm air quality and wildlife habitat in the Hahamongna Watershed Park and that a “slow, steady sediment management program” would better provide flood protection.
But Los Angeles County officials maintained it necessary to remove millions of cubic yards of sediment from behind the dam to minimize flood risk for those along the Arroyo Seco Channel. The 2009 Station Fire caused more than 1 million cubic yards of sediment to flow into the Hahamongna watershed, they said, which reduced the dam’s capacity to 1.3 million cubic yards, less than the 4-million-cubic-yard standard.
On Thursday, March 23, Chalfant ordered the county to revise sections of its Environmental Impact Report that dealt with air pollution and cumulative impacts from other projects.
Ruling that the county’s Final EIR lacked sufficient evidence to prove its mitigation efforts would be effective, Chalfant also laid out a sequence of steps that the county will need to complete in order to move forward with the project.
“At least we have a chance to get a more sensible path forward, said Shannon Griffin, a La Cañada Flintridge mom who has questioned the county’s planned use for dampening the possibly noxious dust that would be created by the project and whether it was water wise.

OUTLOOK photo Opponents of the county’s Devil’s Gate Sediment Removal Plan cheered a judge’s ruling last week ordering the county to revise sections of its Environmental Impact Report about the project. Protesters gathered at the dam in 2013.
OUTLOOK photo
Opponents of the county’s Devil’s Gate Sediment Removal Plan cheered a judge’s ruling last week ordering the county to revise sections of its Environmental Impact Report about the project. Protesters gathered at the dam in 2013.

“We have to take a low, slow approach. And there’s a broad coalition of concerned people and groups that are happy with doing a more moderate approach to this that’s safer to people and to the habitat and to the air and the water and the land.”
The judge reportedly also is requiring that the county obtain approval from the L.A. County Board of Supervisors on a 1-to-1 biological mitigation plan. He’s also instructed the county to clarify that air quality mitigation measures will limit the use of dump trucks to those meeting 2010 emission standards.
Only then can the project go forward, the judge said.
“From what I understand, this is pushing it off, but there is no guarantee of anything right now,” Griffin said. “At least it has got to go through the county supervisors and be reevaluated.”
For more information, visit savehahamongna.org or dpw.lacounty.gov/lacfcd/sediment.

Leave a Reply