Neighborhoods near Devil's Gate Dam brace for trucks and dust from annual basin maintenance – Pasadena Now

Neighborhoods surrounding Devil's Gate Dam in Los Angeles County are preparing for the start of annual maintenance operations on July 1. The project, which includes sediment removal and vegetation clearing, is expected to result in increased truck traffic and dusty conditions in the area.

Los Angeles County Public Works announced that transportation operations are tentatively scheduled for July 15 through October 15. The project aims to extract approximately 150,000 cubic meters of excess sediment from the reservoir basin.

“Some excess sediment will also be used to repair eroded slopes,” the agency said. The work is part of ongoing efforts to manage flood risks and protect downstream communities along the Arroyo Seco, including Pasadena, South Pasadena and northeast Los Angeles.

Residents can expect up to 300 truck movements per day, Monday to Friday, 7 a.m. to 3 p.m., with work at the reservoir continuing until 6 p.m. Trucks will enter the reservoir via Oak Grove Drive and exit onto Berkshire Place to access the highway.

According to the county, work will not be done on weekends, holidays, during major Rose Bowl events or on red alert days. The sediment will be transported to Sheldon Pit in Sun Valley.

The county ensures best management practices are followed to protect air quality. However, the increased activity is likely to impact local air quality and traffic patterns during the duration of the project.

While the Hahamongna Watershed Park Perimeter Trail remains open, access to the reservoir will be restricted during work hours. The county plans to implement safety measures for park visitors throughout the maintenance period.

Public works officials stressed the importance of the project after record rainfall in California. In 2023, the county removed more than 90,000 cubic yards of sediment from the reservoir, allowing the dam to regulate high runoff flows during storm season.

Since the completion of major clean-up works in August 2021, the reservoir can now hold 3 million cubic metres of sediment, significantly increasing its flood management capacity.

The county says the project balances flood control needs with environmental concerns through careful planning, community participation and environmental monitoring. Ongoing efforts aim to improve habitat in the Hahamongna Watershed Park, supporting native and endangered wildlife.

For more information, residents can call the Devil's Gate hotline at (626) 458-2507 or email [email protected]. Updates on the maintenance project are available on the Devil's Gate website.

As the summer progresses, local communities will be closely monitoring the progress of this necessary but disruptive project. The balance between flood protection and quality of life remains a major concern for residents living in the shadow of Devil's Gate Dam.