Sediment Removal & Stream Restoration, Weber Creek, Placerville, California

Client: El Dorado Irrigation District, ECORP Consulting

An uncontrolled release of water and fine sediments occurred as a result of a dam safety draw-down from the El Dorado Irrigation Dam on Weber Creek, near Placerville California. The release of fine silts and sediments from the bottom of the Weber Creek Reservoir filled in pools and other creek habitats for approximately 8 miles along Weber Creek, below the dam. The silt and mud flow caused significant mortality to fish, amphibians, aquatic insects, and other aquatic species. Weber Creek is a tributary to the American River, which is an important anadromous fish stream in Northern California. The California Department of Fish and Game (DFG) issued a Cleanup and Abatement order to EID. The order required the removal of all the silts/muds from the stream and the restoration of the stream to a stable condition.

Northwest Biological Consulting in concert with ECORP developed a restoration/remediation plan to satisfy the cleanup order and obtain the required regulatory permits from a variety of state and federal agencies. The water quality standards for operating within the project were somewhat difficult to meet and required the use of specialized water filtration and settling tanks to meet the standards. In addition, specialized pumps and vacuum trucks and other types of heavy equipment were used to remove all the fine silts and muds from Weber Creek. In addition, hand labor crews removed much of the material from difficult canyon areas. The work was completed and inspected by DFG and all the work was signed off and met all the cleanup and restoration objectives in the cleanup and abatement order. Overall, the project removed over 98% of the fines and muds from Weber Creek.