- Location: Burney, California
- Owner: Pacific Gas & Electric
- Engineer(s): HDR
- Contract Type: Design-Build
- Status: Completed
As the Pit River flows out of Northern California’s Lake Britton, it first begins its journey to Lake Shasta through a 30-mile scenic watershed divided into five segments, or reaches, each created by a dam. Barnard's project entailed installing an 8-foot-diameter pipe and appurtenances through Dams 3, 4 and 5 to increase the river’s flow as part of a relicensing agreement with the Federal Energy Regulatory Commission.
Barnard’s participation in meeting FERC requirements began early in design under this Design-Build contract. Penetration of each dam involved cofferdamming, core drilling, and demolition, as well as structural analysis of the penetration itself. Collaboration between the Owner, Designers, and Barnard personnel resulted in various value engineering opportunities. Installing the 30-foot-tall structural steel intakes and custom-made knife gate valves required work on the water and diving depths up to 100 feet deep. Valvehouse construction required soil nails and rock bolts during foundation excavation, drilling 30 to 70 into the hillside, as well as shotcrete support walls. We installed #10 ksi bar with double corrosion protection and followed up with load-testing. In addition to the flow modifications, the project added 38 turnouts to the existing River Road, replacement of two bridges, drainage system upgrade, and recreation improvements throughout the Pit River watershed. All of this work took place in a highly sensitive environment under close scrutiny by regulatory agencies.