Council To Get ‘Big Dig’ Project Update Wednesday

The City Council will receive an update on the Devil’s Gate Restoration Project at its meeting with Los Angeles County Supervisor Kathryn Barger at 8 a.m. Wednesday.

The project, also known as “The Big Dig,” is a four-year effort to increase flood protection for communities downstream of Devil’s Gate Dam and restore habitat within a popular section of the Arroyo Seco Watershed.

The county Public Works Department plans to remove 1.7 million cubic yards of sediment from the reservoir immediately behind the 100-year old dam.

In addition to providing flood relief to communities that have endured more than a decade of elevated flood risk along the Arroyo Seco, the project will establish a permanent stormwater maintenance area that allows for the creation of 70 acres of enhanced habitat and recreational opportunities.

The project has come under fire by residents of Pasadena and nearby La Cañada Flintridge.

Devil’s Gate is the oldest dam constructed by the L.A. County Flood Control District, providing flood protection for Pasadena, South Pasadena and Los Angeles.

A large amount of sediment had not been removed from Devil’s Gate since 1994 when workers hauled out 160,000 cubic yards. The Station Fire in 2009 then dumped a million cubic yards of soil and debris into the basin.

The Board of Supervisors voted on July 7 to approve a settlement between L.A. County, the Arroyo Seco Foundation (ASF) and the Pasadena Audubon Society (PAS) that reduced the negative impacts of the project on endangered bird species within the area.

Barger last updated the council on the project in 2018.

“We were able to reduce the footprint of the project by 20 acres,” said Tim Brick, managing director of the Arroyo Seco Foundation. “We were able to improve the conditions of the habitat in 20 acres they had previously set. They started with 70 acres and we were able to reduce it. So we were also able to get some substantial improvements in the habitat restoration program and to protect some of the key areas in Hahamongna.”

As part of the restoration, grading work to properly contour slopes will be followed by planting and seeding with native riparian species. Approximately half of the vegetation will be harvested from nearby Hahamongna Watershed Park by the Hahamongna Native Plant Nursery.

The work at nearby Johnson Field and Mining Pit was previously scheduled to be completed by mid-December.

For more information on the full range of enhancements at Devil’s Gate Reservoir, visit DevilsGateProject.com. You can also ask questions or share concerns at devilsgateproject@pw.lacounty.gov or call the Devil’s Gate Project Hotline at (626) 458-2507.