As engineers continue to work to repair the main spillway at the Oroville Dam, they’ll know going forward that they won’t be repeating the mistakes that led to its failure in February of this year.
On Wednesday, a panel of engineers tasked with looking into the spillway failure released a report citing 24 possible causes for the failure, though they stressed that the report was preliminary and that there may be other factors identified as the investigation moves forward. The report doesn’t identify one singular issue that ultimately led to the failure, but it does say that overall, the dam spillway wasn’t strong enough to handle the weight of the water when dam workers opened the spillway back in February.
The report comes as the state is hoping the federal government will foot the bill for the majority of the dam repairs. The state has secured a $500 million line of credit to front the cost of the repairs, which is about the same amount of money the state expects the fixes to cost, while it waits to find out whether FEMA will grant a request to cover 75 percent of the total repair cost. The state considers all of the repair work emergency management, qualifying it for FEMA funding, and says that state water contractors like the Metropolitan Water District of Southern California who get water from Lake Oroville, the second largest reservoir in California, will pay the rest.
For more on the history of the Oroville Dam and what led to February's massive failure, check the Sacramento Bee on Sunday for special coverage.
Ryan Sabalow, reporter for the Sacramento Bee covering water, drought and the environment; he tweets @RyanSabalow