Sediment Management

Picture of Big Tujunga Dam

ANNOUNCEMENTS

A Revised and Recirculated Initial Study/Mitigated Negative Declaration (IS/MND) is currently being prepared. A public review period is planned for early 2020.

The Big Tujunga Reservoir Restoration Project proposes to remove up to 4.4 million cubic yards (mcy) of accumulated sediment from Big Tujunga Reservoir. The Station Fire resulted in an additional 1.3 mcy of debris. This material must be removed as soon as possible to maintain the Dam as a fully functional component of Los Angeles County Flood Control System.

The project bid period is anticipated in Summer 2021. Activities at Maple Sediment Placement Site are scheduled to start in Fall 2021 before sediment removal activities begin in Spring 2022.

For additional project information, please click the links in the section titled 'RESOURCES' below:

PROJECT SUMMARY

The 2009 Station Fire was the largest fire in Angeles National Forest (est. 1892) recorded history and burned over 160,000 acres in the San Gabriel Mountains. Approximately 87% of the watershed tributary to Big Tujunga Reservoir was burned, making sediment deposition inevitable during subsequent storm events. The storms that occurred in the wet seasons after the fire increased sediment accumulation in the reservoir by more than one million cubic yards.

The sediment in the reservoir can impact the operation of the valves and reduce the capacity for water conservation and flood control. Sediment removal is necessary to maintain the operability of the dam and protect the communities and environment downstream of the dam.

Pursuant to the California Environmental Quality Act (CEQA) an Initial Study/Mitigated Negative Declaration (IS/MND) was originally prepared in 2013. A Recirculated IS/MND is currently being revised and will be recirculated in early 2020.

Big Tujunga Reservoir before the Station Fire Big Tujunga Reservoir before the Station Fire
Big Tujunga Reservoir after the Station Fire Big Tujunga Reservoir after the Station Fire
Pursuant to the National Environmental Policy Act (NEPA) an Environmental Assessment (EA) is being prepared. A public scoping meeting will be conducted by the United States Army Corps of Engineers.

Maple Canyon Sediment Placement Site Maple Canyon Sediment Placement Site Big Tujunga Reservoir Project Map Big Tujunga Reservoir Project Map Photo Taken After Big Tujunga Dam Seismic Rehabilitation and Spillway Modification Project Photo Taken After Big Tujunga Dam Seismic Rehabilitation and Spillway Modification Project

RESOURCES

CONTACTS

For more information on the project or to be added to the project mailing list, please contact reservoircleanouts@dpw.lacounty.gov
Updated on: 09/11/2019
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