New Bullards Bar Dam Atmospheric River Control (ARC) Spillway Project

The Project involves constructing, operating, and maintaining a new additional spillway and associated facilities on the left abutment of New Bullards Bar Dam. New Project facilities include: (1) a 500-foot-long approach channel excavated adjacent to the existing spillway to connect the spillway control structure and chute to New Bullards Bar Reservoir; (2) a gated control structure located directly downstream of the approach channel; (3) a concrete-lined spillway chute located downstream of the control structure equipped with a flip bucket directing flows toward the North Yuba River canyon; (4) a 690-foot-long excavated discharge channel that discharges to the North Yuba River; and (5) an operations platform and gate control building, electrical systems for gate operation and monitoring, and new permanent access features (e.g., roads, operations platform, overlook site access, and maintenance benches). The spillway chute will be an open channel designed with a freeboard capable of discharging 64,000 cubic feet of water per second from New Bullards Bar Reservoir for flood control. The ARC Spillway will mainly operate to reduce flood risk in the Yuba-Feather River system. The Project also requires relocation of an existing overlook site at New Bullards Bar Dam’s left abutment, relocation of a short segment of Marysville Road over the new spillway, and establishment of a permanent disposal area for excess excavated soil and rock associated with the Project’s construction. Construction is anticipated to occur over approximately four years.