After years of litigation, Los Angeles County reached a settlement over the Devil’s Gate Dam sediment removal project, agreeing to limit the long-term scope of the controversial “Big Dig.”
The settlement, which county supervisors approved Tuesday, requires the county Flood Control District to exclude 14 acres from the project, which has sought to remove up to 1.7 million cubic yards of sediment from behind the dam, according to the agreement.
Additionally, roughly 6 additional acres will be maintained less frequently than other sections of the Hahamongna Watershed Park after the project concludes, decreasing the amount of digging that needs to be done there in future years.
Altogether, the settlement reduces the project area from 70 acres to 50 acres that will need to be maintained. The settlement also limits the county to 220,000 cubic yards of earth dug per year during its maintenance period after the main project ends.
During the same post-project period, district sediment removal trucks will also be capped at 300 round-trips per day, though the agreement does not state how many trips the trucks will actually make. An estimate presented to the La Cañada Flintridge City Council in May, when the second removal phase of the project began, trucks carrying sediment could be making up to 495 trips a day until the end of November, depending on weather.
The sediment removal project was proposed in 2010, after combined damages from the Station Fire and rainstorms caused 1.3 million cubic yards of earth from the San Gabriel Mountains to pile into the reservoir behind the dam.
But in a series of public meetings held before, and as work began in 2019, many LCF residents opposed the project, citing environmental and air quality concerns, particularly considering the project site’s proximity to local schools.
Because school activity is largely on pause for the summer, however, complaints have dropped, said Director of Public Works Patrick DeChellis.
L.A. County will also purchase native seeds and plant materials from a nursery operated by the Arroyo Seco Foundation, one of the two nonprofits that sued the county over the project in 2017, as part of the project area’s restoration process.
“I’m very pleased,” said Tim Brick, managing director of the Arroyo Seco Foundation, over Zoom. “It’s been a 10-year crusade. We didn’t get everything we wanted, but we did get a lot of significant improvements in the project, and I think we really created a good basis for a more environmentally sensitive approach to Hahamongna in the future.”
The settlement was made between the Flood Control District and two organizations, the Arroyo Seco Foundation and the Pasadena Audubon Society. The two corporations had first sued the county in 2014, saying that the project violated California environmental law.
A court ruled in their favor, requiring the county to revise its Environmental Impact Report to reduce the impact of the project. The project, which was originally planned to remove a maximum of 2.4 million cubic yards of sediment, was reduced to 1.7 million cubic yards.
The two nonprofits sued the county again in December 2017, saying the project continued to violate environmental standards.
“Hopefully, there’ll be cleaner air than there would have been. That’s our goal,” said Laura Solomon, president of the Pasadena Audubon Society. “And we know that the restoration of the dug-up areas is going to be improved, so the quality of life for the wildlife is better.”
As part of the settlement, the county also agreed to allow researchers from UC Riverside to monitor emissions from the trucks used in the project and to incentivize the project contractor to use alternative fuel trucks — such as those that run on electricity.
“Many of the benefits of the lawsuit have come during the process that we engaged in,” Brick said. “For instance, we offered technical advice on air quality issues, we got them to do a study of the potential for using clean air trucks [and] we introduced them to manufacturers of clean air trucks.”
County Supervisor Kathryn Barger authored the motion approving the settlement, saying in a news release that the supervisors are “very pleased to reach this agreement with our environmental partners and key stakeholders.
“In collaboration with our communities and environmental leaders,” she continued, “we made significant progress to complete this critical work.
“The resulting project delivers long-term flood protection for the communities in Pasadena, South Pasadena and northeast Los Angeles while improving recreational areas and protecting … habitat.”
