Caltrans District 2
Lake Almanor Spillway
SR-89 Plumas County
The California Department of Transportation, using both State and Federal funds, will be replacing the existing Lake Almanor Spillway Bridge at PM 30.0 on State Route 89 in Plumas County during the 2018 construction season. The existing bridge was built in 1963 and is being replaced due to:
- Severe deterioration of the deck and reinforcement caused by chloride contamination.
- Seismic design deficiencies.
- A need for standard shoulders and an updated bridge barrier rail.
The new bridge will be built on the existing bridge alignment and will be approximately the same length as the existing bridge. Double column piers will be constructed atop spread footings, and Cast in Drilled Hole piles will be constructed to support the abutments. The bridge deck will consist of fiber reinforced concrete with epoxy coated deck reinforcement. A polyester concrete overlay and new striping will complete the deck surface.
One-Month Detour Alert
In order to construct the new bridge, it is necessary to detour traffic down onto the spillway, directly north of and parallel to the existing bridge. While the existing bridge is being demolished and on-spillway detour constructed, traffic will be temporarily diverted onto State Route 147 for approximately one month. The signal-controlled one-way detour on the spillway will operate during the remaining construction period. Construction may occur on the weekends in order to be completed in one season. Night work is not anticipated.
Statewide Alerts and Other Information