SCH Number 2019039037

Project Info

Title

Upper Blue Lake Dam Seismic Retrofit Project

Description

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.

3 documents in project