Oroville Dam repair costs soar
Unexpected problems lead repair costs to double to almost $500 million
The reconstruction of Oroville Dam’s flood control spillway is likely to cost as much as $500 million, state officials said Thursday, as design changes and unexpected additional work has inflated the cost of the project.
Originally budgeted at $275 million, the repair has grown to cover a greater level of protection for the dam’s emergency spillway — whose near failure in February sparked the evacuation of 188,000 downstream residents — as well as unforeseen problems in the bedrock beneath the main spillway, said Erin Mellon, a spokeswoman for the state Department of Water Resources.
Mellon said the state hopes to recover up to 75 percent of the reconstruction costs from the Federal Emergency Management Agency. But she said water districts that store water behind Oroville Dam, such as the Metropolitan Water District of Southern California, the Santa Clara Valley Water District and the Kern County Water Agency, will be expected to pick up whatever costs the federal government won’t cover.
Mellon said state officials have known for several months that the cost would exceed the original budget. General contractor Kiewit Corp obtained the two-year, $275 million contract in April, when the reconstruction project was still only 30 percent designed, she said.
Mellon said a more accurate cost estimate should be available by Nov. 1.
Although the reconstruction costs have risen, Mellon noted that the cost of handling the initial emergency in February came in at around $160 million, or more than $100 million below original estimates.
The higher costs for the reconstruction came to light as officials from DWR and Kiewit led a media tour of the construction site, where 700 workers are racing to meet a self imposed Nov. 1 deadline to have the dam ready for wet weather.
Although the spillway project won’t be completely finished for another 12 months, the spillway should be able to release 100,000 cubic feet of water per second during the upcoming rainy season.
“I don’t want to jinx it, but we’re ahead of schedule,” said Jeff Petersen, Kiewit’s project manager. The rain expected
to hit the region late Thursday might cause slight delays but wouldn’t derail the project, he said.
Petersen told reporters that costs rose in part because workers discovered that a portion of the main spillway was built on rock that was deemed unsuitable. As a result, workers had to dig a lot deeper into the bedrock before laying the new concrete. That led to higher costs for excavation and concrete to fill in the hole.