The California Department of Water Resources has named the members of a five-person independent board of consultants to help investigate the cause of the main spillway failure at Oroville Dam and ascertain if the failure mode could occur again.
In a letter submitted to the Federal Energy Regulatory Commission on Feb. 17, DWR said it had selected the following experts:
- Kerry Cato, PhD,
- John J. Cassidy, PhD
- Eric Kollgaard, B.S.
- Faiz Makdisi, PhD
- Larry Nuss, M.S.
This board is engaging with DWR and its emergency response partners “to review and assess operations, conditions and risk reduction measures associated with the dam and appurtenant structures.” DWR says the board will continue in this role during the repair of the main and emergency spillways at Oroville Dam.
DWR also says in the letter that the process to establish in independent forensic review is under way, with the U.S. Society on Dams and the Association of State Dam Safety Officials working to identify an independent team of experts to perform this function. DWR says it estimates the forensic review will ensue in about three months and will include an independent assessment of the conditions that led to the incident.
Regarding work to be done at Oroville Dam, DWR says, “The near-term recovery effort will involve significant reconstruction on an accelerated time schedule to meet the demands of the 2017-18 flood season and the long-term recovery will require a thorough examination of the spillway failure causes.”
Given the unique situation and “compressed timeline,” DWR asks FERC to provide specific assistance:
- Full-time FERC staff who can provide immediate oversight and approval as plans and specifications are being developed
- Federal assistance to streamline or eliminate any permitting that normally would be required for a repair of this magnitude in order to expedite construction and provide a safe structure by the 2017-18 flood season
- Constant and immediate oversight of board of consultants
- Full-time FERC staff to review and approve construction activities, including any changes necessitated by conditions encountered in the field
- Flexibility, including time requirements associated with meetings and data packages
In its most current incident update, DWR reported that on the morning of Feb. 20, outflow from the DWR flood control spillway was increased to 60,000 cfs from 55,000 cfs in anticipation of an expected increase in inflows. DWR reported that work continues on the area below the spillway, the monoliths, access road, and various eroded areas created by emergency spillway runoff. Rock, aggregate and cement slurry are being placed in areas affected by erosion and this work will continue 24 hours a day.
For more detailed information on what happened at Oroville Dam, click here.