Why we’re getting jacked:
‘Patch and Pray’ Crack Repairs on Oroville Dam Emergency Spillway: UC Berkeley Civil Engineer
“They put cement into the cracks and troweled it over,” a Berkeley civil engineer said. “I call it ‘patch and pray”’
Six months before rushing water ripped a huge hole in a channel that drains a Northern California reservoir, state inspectors said the concrete spillway was sound. As officials puzzle through how to repair Oroville Dam spillway, federal regulators have ordered the state to figure out what went wrong.
Earlier inspection reports offer potential clues, including cracks on the spillway surface that if not properly repaired could let water tear through the concrete. In recent years, construction crews patched cracks — including in the area where water burrowed a huge pit last week. …
Last August, a team of inspectors did not check the channel on foot but instead from afar, also concluding that everything looked fine. …
Robert Bea, professor emeritus of civil and environmental engineering at University of California, Berkeley, said it’s “obvious those repairs didn’t work.”
“We don’t have details on the repairs, but they put cement into the cracks and troweled it over,” Bea said. “I call it ‘patch and pray.”’
On Monday, federal regulators told the department it must enlist a group of independent consultants both to assess what went wrong and to recommend long-term fixes.
Documents and interviews show that crews were patching cracks in 2009 and 2013. …
“Any type of evidence that might have been there is gone,” Eric Holland of the water resources department’s dam safety division said. “Everything has been washed away.”