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Mon March 09, 2020 - West Edition #6
SACRAMENTO, Calif. (AP) In an unusual reversal, federal regulators agreed to cover about $300 million in repair costs at the Oroville Dam, where a spillway collapse three years ago prompted the evacuation of nearly 190,000 people in Northern California.
The Federal Emergency Management Agency said last March that it wouldn't pay for repairs involving damage regulators said existed at the Sierra Nevada dam before the collapse. But after an appeal, FEMA agreed to cover the repairs, the Sacramento Bee recently reported.
The state now expects to be reimbursed for about $750 million of the $1.1 billion in repair costs, Erin Mellon, spokeswoman for the state Department of Water Resources, said in an email to the Bee.
"This is pretty rare, and for California it's huge money," said Jerry Quinn, a Sacramento consultant who helps government agencies recover money from FEMA, told the paper.
Local water agencies will cover anything not paid by the federal government.
The dam northeast of San Francisco was built in 1968. In February 2017, storms drenched the state, and a concrete flood-control chute broke apart as it carried heavy flows.
Dam operators reduced the flow and allowed water to run down an emergency spillway — essentially a low area on the reservoir's rim — but the flow began eroding the earthen embankment that had never been used. Authorities suddenly had to order an evacuation of people living in communities downstream.
The threat of a dam collapse that would unleash a torrent of water did not happen, however, and people were allowed to go home days later.
An independent panel of dam safety experts later released a nearly 600-page report that blamed the crisis on "long-term and systemic failures" by California dam managers and regulators to recognize inherent construction and design flaws in the dam.
On Feb. 7, 2017, a 200-ft. pothole opened up in the main spillway of the Oroville Dam in northern California. With snowpack at 150 percent above normal in the Sierra mountains, and Lake Oroville still rising, officials reduced the amount of flow on the main spillway. On Feb. 12, as 188,000 residents downstream nervously watched on the news, water began tumbling over the never-before-used emergency spillway.
Water crested the 1,000-ft.-long emergency spillway and began carving a path down the dirt hillside, washing debris into the Feather River below. This created another dilemma. The dirt under the emergency barrier eroded faster than expected, and the integrity of the barrier was compromised. Officials evacuated residents downstream and increased the flow on the damaged main spillway.
The increased crater in the main spillway redirected the flow of water and created a separate channel to the right of the concrete structure, carving out even more dirt and debris. But it decreased the pressure just enough to allow officials to begin repairing the emergency spillway — a task that started in May of 2017 and is still ongoing.
With the clock ticking, and downstream residents waiting to return home, officials needed to repair the erosion and prevent further threat of collapse quickly and effectively. They just didn't have the right equipment.
Jay Selby, of Selby Soil Erosion Control, did. Selby answered the emergency call and began re-seeding the slopes of the emergency spillway that night with his fleet of Apex hydroseed applicators. Selby helped control erosion on the hillside and the critical ground beneath the emergency spillway barrier. When it came time to repair the concrete main spillway, Selby got another call, this time to help stabilize the haul roads and pads that cranes needed to access the job site.