Main portions of the Oroville Dam's gated spillway are expected to see repairs soon.
The state's Department of Water Resources said a notice to begin work is scheduled to be issued next week for contractors on the spillway.
Actual work will follow towards the end of May or early June.
U.S. Rep. John Garamendi (D-Walnut Grove), whose district includes Oroville, said repairs need to be done quickly.
"Hopefully it'll just be gentle snow melt through the spring and into the summer, but it could be just the opposite," he said.
DWR hopes to complete a concrete cut off wall, which will help prevent erosion, by Nov. 1. The ultimate goal is to prevent water from flowing down the emergency spillway again.