Winter’s coming — is it ready?
The race to fix the Oroville Dam is over — or is it? Nearly two years ago, a giant hole opened up on the Oroville Dam’s main spillway while it was releasing water during the winter rains. Dam managers then turned to an emergency spillway, but it, too, started to erode.
The result was mass chaos as tens of thousands of people in the communities downstream packed their cars and tried to beat a hasty retreat. Luckily for them, water levels in the reservoir fell before major flooding could ensue.
Following the dam’s nearcatastrophic failure, crews have been working virtually nonstop to repair the two spillways. On Nov. 1, state water officials announced they’d met their deadline for the rebuild. The repairs cost a staggering $1.1 billion — far more than the initial estimate of $275 million.
But the state can’t declare victory just yet. In an Oct. 25 letter to the state Department of Water Resources, federal regulators expressed concerns about the dam’s ability to weather a major flood.
“A more robust and resilient design of the emergency spillway may be required to prevent the possibility of moderate to severe damage to the emergency spillway structure for the expected full peak flow,” wrote Frank Blackett, regional engineer for the Federal Energy Regulatory Commission.
The type of major flood federal regulators are concerned about would be highly unusual — an extreme event that has yet to happen in the history of the dam’s existence.
The state water resources department says that the public has nothing to be concerned about, because federal regulators have worked alongside them on the repairs and that public safety will be assured in the case of a more standard flooding event.
“FERC has not expressed concern about the repairs,” said Erin Mellon, water resources department’s assistant director for public affairs. “FERC has simply stated that additional work may be needed in the future.”
Still, the federal warnings must be treated seriously.
An independent review of the dam found the state had a history of poor maintenance and had failed to perform its oversight duties adequately. Given the dam’s recent track record, rebuilding it to the highest level of safety is the least we should do.
Plus, in an era of climate change, extreme events happen with greater regularly.
Today’s additional work can easily become tomorrow’s necessity.