Damaged Spillway Being Carefully Monitored as Lake Oroville Releases Resume

The California Department of Water Resources Friday provided an update on repairs underway at Oroville Dam and plans to begin releasing water from the damaged main spillway in anticipation of upcoming storms.

DWR will begin releasing 50,000 cubic feet per second of water from the spillway, with the goal of dropping Lake Oroville water levels from 864 feet to closer to 825 feet. Releases are expected to continue for approximately one week and will likely result in a 10 to 15 foot increase in water levels in the Feather River. DWR plans to temporarily shut down operations at the Hyatt Powerplant while the spillway is in use.  

During a morning media briefing, Acting DWR Director Bill Croyle reported that the spillway deck has been thoroughly cleaned and sealed and that “rock bolts” have been installed in an effort to prevent further erosion while water is being released. He also noted that the damaged spillway will likely be used three times through June 1, but the integrity of the spillway and changing water supply conditions will continue to be assessed as part of operations decisions.

“What you see today, you might not see tomorrow,” said Croyle regarding conditions at the lake. “This is an impaired system… every day we are continuing to assess the conditions…”

Other emergency recovery activities include the removal of 1.25 million cubic yards of debris from the diversion pool, mitigation of naturally occurring asbestos, road repair, and efforts to mobilize a rock crushing plant and concrete batch plant for repair work. DWR also is working with the California Department of Fish & Wildlife to ensure that Chinook Salmon and steelhead populations remain healthy.

The total cost for repairing damage from the Oroville spillway incident is currently estimated between $100-200 million, but according to Croyle will likely be higher. Emergency recovery efforts through February came in at an average cost of $4.7 million per day.

For the most current information on the Oroville spillway incident and repairs, please visit DWR’s website.  


Photo credit: DWR, Kelly M. Grow