The California Department of Water Resources says crews are pouring the last bit of concrete on the bottom sections of the new Lake Oroville main spillway project.
Erin Mellon with DWR says that Wednesday is the deadline for the major work to be completed.
"The work that will continue past Nov. 1 on the main spillway is going to be focused on site cleanup, sealing of drains, concrete seams and drainage pipes," Mellon said.
Crews are also working on a cutoff wall to limit erosion below the emergency spillway.
The main spillway failed in February and DWR allowed water to overtop the emergency spillway. That caused significant erosion to the hillside below. About 180,000 people were evacuated.
Crews will tear down and rebuild the top 730 feet next year. They will also begin construction of a splash pad and partial ramp below the emergency spillway next year.