One year after the Oroville Dam’s concrete spillway ruptured on Feb. 7, 2017, crews working day and night have made the most critical repairs to what has become an $870 million project. Kiewit Corp. of Omaha, Neb., fixed the dam’s main spillway and an emergency spillway that also was damaged by unprecedented water releases forced by record rainfall in Northern California.
The work has continued in 2018, while the California Department of Water Resources (DWR) and Washington, D.C., discuss the extent to which the Federal Emergency Management Agency will pay for repairs. Meanwhile, Governor Jerry Brown signed legislation that codified the annual inspections DWR already conducts of the vast majority of the 1,249 dams the department oversees. The law requires “low hazard potential” dams be evaluated at least every other year.
Chico Enterprise-Record » An independent review board hired by the state Department of Water Resources Oroville Dam has released its first report with an eye toward improving the facility’s future operations. Among the suggestions: a second gated spillway, improved monitoring, and clear operational planning that takes into account the impact of climate change on the dam’s functions. (The webpage includes an embedded copy of the independent report.)
California Department of Water » Crews continue to place leveling concrete on the upper chute of the Lake Oroville main spillway, while other workers install forms over a structural rebar panel to prepare for the placement of more structural concrete. Meanwhile, mechanical demolition continues on the dentates, the big tooth-like structures that disperse water at the bottom of the main spillway.
Chico Enterprise-Record » The state Department of Water Resources has beefed up its response to the independent forensic report on what caused the Oroville Dam spillway failure last year. A revised dam safety policy, which will “further define roles and responsibilities” of the executive-level engineer, the chief dam safety engineer and other related State Water Project divisions, should be released by the end of the year.
Chico Enterprise-Record » The state Department of Water Resources says it may appeal a Butte County Superior Court judge’s ruling that allows the Butte County District Attorney’s environmental lawsuit to continue. This comes as Judge Stephen Benson overruled DWR’s demurrer, or objection to the lawsuit.
KCRA » The California Department of Water Resources said it is on track to meet the Nov. 1 deadline for its second phase of construction on the Oroville Dam spillways. Crews have conducted controlled blasts to remove temporary concrete on the primary spillway. Concrete is also being poured on the emergency spillway.
Chico Enterprise-Record » The agency has provided the department with about $139 million for emergency restoration work, including debris removal. FEMA is currently considering DWR’s request of $500 million to repair the main spillway and $75 million to repair the emergency spillway. The department is also seeking reimbursement for damages to Hyatt Powerplant, transmission lines and the Feather River Fish Hatchery.
Chico Enterprise-Record » A bill proposed by Assemblyman James Gallagher which would take the State Water Project out of the hands of the state Department of Water Resources passed unanimously on Tuesday through a legislative committee. Assembly Bill 3045 passed 15-0 through the Assembly Water, Parks, and Wildlife Committee and is now headed to the Assembly Appropriations Committee.
Chico Enterprise-Record » The state Department of Water Resources said periodic shaking at the dam picked up by USGS monitors has been caused by controlled blasts supporting construction efforts at the site, where workers have been repairing the dam’s main spillway after it crumbled last year, among other projects. So far in April, the USGS has recorded at least three chemical explosions around the main spillway.
The Sacramento Bee » Last week, the California Department of Water Resources said the storm might cause water levels in the Lake Oroville reservoir to rise to the “trigger elevation” of 830 feet. At that point, DWR officials planned to open the spillway gates and release water down the 3,000-foot-long concrete chute. But the lake level only reached 799.7 feet over the weekend.
San Francisco Chronicle » Oroville Dam operators said Tuesday they may have to release water over a partially rebuilt spillway for the first time since repairs began on the badly damaged structure last summer. Department of Water Resources officials said anticipated storms could trigger releases this week or next.
Chico Enterprise-Record » There was quite a buzz around Oroville last week about aerial photos that showed a wet streak down the face of the repaired main Oroville Dam spillway. But it was something that had been expected, and the Department of Water Resources said as early as January that it might happen.
Chico Enterprise-News » Kiewit Infrastructure West Co. said on Wednesday that construction of the underground wall below the Oroville Dam emergency spillway completed in early March. The 1,450 feet long wall, drilled 35-65 feet into bedrock, is one preventative measure against the type of erosion that occurred there last year, should the emergency spillway ever be used again.
The Sacramento Bee » Gov. Jerry Brown has signed legislation that would tighten dam inspection standards following last year’s near catastrophe at Oroville Dam. On Monday, Brown signed Assembly Bill 1270. The bill codifies practices that state dam officials already were largely doing, but that the state’s Water Code only required they perform “from time to time.”
The Mercury News » The state Department of Water Resources is still expecting the federal government to pay the bulk of the cost of repairing the Lake Oroville spillways. The estimated cost is up to $870 million, and north state congressmen had indicated the Federal Emergency Management Agency had some doubts whether it could reimburse costs for a redesigned structure.