Tuesday, the Department of Water Resources (DWR) provided an update on construction work on the Lake Oroville Spillways Emergency Recovery Project.
Continued Construction on the Main Spillway
·DWR remains focused on meeting its primary objective of repairing and reconstructing the main spillway by November 1 to handle flows of 100,000 cubic feet per second (cfs).
·Work will continue well past November on both the main spillway and emergency spillway. The state’s contract with Kiewit Infrastructure West is currently until January 2019.
·This year, 730 feet of main spillway leading to the radial gates will be patched, reinforced and left in place. It will be removed and reconstructed with structural concrete in 2018.
·There are 42 days left until November 1:
o Placement of reinforced, structural concrete is 30 percent complete. By November 1 there will be 1,220 feet of spillway chute with structural concrete – 870 feet on the upper chute of the spillway and 350 on the lower chute of the spillway.
o The 1,050-foot middle section of the spillway chute, including filling in the two scour holes, is now 50 percent complete, with approximately 170,000 cubic yards of roller compacted concrete placed. This year, there will be an estimated 350,000 cubic yards of RCC placed. In 2018, this middle section will be completed to final design with structural concrete.
o On September 17, crews placed 3,143 cubic yards of roller compacted concrete on the middle section of the spillway chute, a record amount for a single 12-hour shift.
o Crews have installed 1,725 slab anchors to date in the structural concrete sections – nearly 60 percent of what is needed for 2017.
Construction at the Emergency Spillway
·DWR continues to make progress at the emergency spillway, and is on schedule to complete construction of the secant pile wall, or cut-off wall, in December 2017 or January 2018.
·Crews have completed 22 percent of the secant pile wall.