Oroville Mayor: Spillway Cracks 'No Big Deal' -- but State's Failure to Communicate About Them Is

The mayor of Oroville says she knew about cracks in the replacement spillway at the dam just up the Feather River from her city -- and is not concerned. But she's criticizing state water officials for what she calls their failure to communicate effectively with her town.

Linda Dahlmeier said the Department of Water Resources should have proactively communicated that cracks were expected in newly placed concrete on the spillway, but has instead created a "firestorm" in a community that was rattled by sudden evacuation orders last February.

Nearly 200,000 people were forced to evacuate when engineers feared that damaged spillways at Oroville Dam would unleash an uncontrolled wall of water that would inundate Oroville and communities downstream. The crisis was averted.

The existence of small cracks in the new concrete was first reported by KQED earlier this week after the Federal Energy Regulatory Commission posted communications about them online. Officials downplayed concerns about them Thursday in a conference call with reporters, saying hairline cracks are normal and expected in reinforced concrete because it shrinks as it cures.

Dahlmeier said that could have been communicated more effectively before the letter went public.

"Many of us that have been up there have seen those hairline fractures and it's no big deal because it was explained to us one at a time," Dahlmeier said.

But many residents of Oroville don't trust what they're hearing from the Department of Water Resources, she said, and officials in the agency's Sacramento headquarters have failed to address the concerns of people living in the shadow of the nation's tallest dam.

Dahlmeier said state officials should put in the effort to visit Rotary Clubs and schools to meet people in small groups and answer their questions honestly.

"I don't want to hear it from Sacramento anymore," she said. "I want to hear it wordsmithed from somebody that lives here and knows how to speak to my community and my people."

Crews are nearly finished preparing the half-completed main spillway for the rainy season and will spend the coming months working on the adjacent emergency spillway.

Two community meetings are planned next week in Oroville and Yuba City. Erin Mellon, a spokeswoman for the department, said officials also have monthly calls with stakeholders and elected officials and send emails to community members every time they issue a press release.

"There is only so much we can simplify and still provide detailed descriptions and answers that are accurate," Mellon said.

Jeff Petersen, project director for Kiewit Infrastructure West, which has the contract to rebuild the spillways at an estimated cost of $500 million, said the cracks don't affect the structural integrity of the spillway. Adjusting the concrete mixture could reduce the number of cracks, Petersen said, but experts need to be careful not to reduce the concrete's strength.

Engineers believe the number of cracks is "in the hundreds," with the biggest about the width of a human fingernail and the average about half that thickness, said Jeanne Kuttel, chief of the Department of Water Resources engineering division and incident commander for the spillway project.

Federal regulators told state officials that they share the state's conclusion that "the current condition of the hairline cracking does not warrant repair at this time."