Regional Water Quality Control Board, Region 5 (Central Valley), Sacramento
Upper Blue Lake Dam Seismic Retrofit Project
MND - Mitigated Negative Declaration
Pacific Gas & Electric Company (PG&E) is proposing to construct the Upper Blue Lake Dam Seismic Retrofit Project at Upper Blue Lake reservoir in Alpine County. A preliminary seismic slope stability evaluation of the dam that was conducted in 2014 indicated that the dam would likely liquefy during an earthquake. The proposed project would improve the seismic stability of the dam by placing a 50-ft wide by 175-ft long rock fill buttress on the upstream side of the Upper Blue Lake dam. The addition of the buttress would require an upstream extension of two low level outlet pipes by approx. 50 ft and reconfiguration of the intake structure and trash rack. The project area consists of the dam retrofit area, bypass piping, staging and parking areas, and spoils placement and storage areas.
Department of Fish and Wildlife, Region 2Cal FireCalifornia Department of Parks and RecreationCalifornia Energy CommissionCalifornia Public Utilities CommissionCaltrans, District 10Department of ConservationDepartment of Toxic Substances ControlDepartment of Water ResourcesNative American Heritage CommissionOffice of Historic PreservationResources AgencyState Lands CommissionState Water Resources Control Board, Division of Water Quality