California races nature, clock to make key dam repairs
San Francisco — California is not just fighting nature as it attempts to repair the damaged main spillway at the nation’s tallest dam, pounded last month by surging storm waters. It’s also racing the clock.
Safety experts say there is no time for delays in the state plan to restore the critical main spillway at the 770-foot Oroville Dam, and they warn that California would face a “very significant risk” if the spillway is not in working order by fall, the start of the next rainy season.
A Nov. 1 target to fix the spillway presents “a very demanding schedule, as everyone recognizes,” said a report prepared by an independent team of consultants and submitted to federal officials last week. A copy of the report was obtained Wednesday by the Associated Press.
Also Wednesday, the state Legislative Analyst’s Office warned that tens of billions of dollars are needed for repairs and updates for aging dams, levees, wetlands and other projects in California’s flood-management system.
Authorities have not provided a current estimate for the cost of repairs needed on the Oroville dam spillways.
The report on the spillways sketches a challenging array of problems at the Northern California dam. Last month, authorities ordered the evacuation of 188,000 people downstream after surging releases of water tore away big chunks of the main spillway and then the dam’s second, emergency spillway.
At the time, officials feared rapid deterioration of the emergency spillway could send large, uncontrolled torrents of water from the lake behind the dam through surrounding towns. The spillway is used to release water when the reservoir is nearing full capacity.