OROVILLE (AP) — California water officials said Wednesday that the $1.1 billion spillway at the nation’s tallest dam will be in full working order if it’s needed this winter, nearly two years after it was damaged and thousands were forced to flee.

Crews have finished pouring concrete on the main spillway at Oroville Dam, though it still needs to cure for a month and other work is necessary before it can be used, the California Department of Water Resources announced. Crews will also continue pouring concrete on an adjacent emergency spillway.

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Both spillways at the dam crumbled and fell away during heavy rains in early 2017, prompting fears a catastrophic release of water. State officials had assured the public for days leading up to the failures that the dam could handle rising waters amid persistent and heavy rains.

Then on Feb. 12, 2017, officials ordered an immediate evacuation, fearing that a concrete weir that holds water in the lake could collapse within an hour.

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The panic of the sudden evacuation turned into frustration and anger when many of the evacuees found themselves stuck in gridlocked traffic hours after fleeing the danger zone. Residents were allowed home a few days later after water behind the dam receded and the danger passed.

“More than 700 construction workers … literally worked day and night to make incredible progress during the 2018 construction season,” Tony Meyers, project manager for the Department of Water Resources, said in a statement.

Officials said in September that the cost for reconstruction had ballooned to $1.1 billion and said the figure could still rise. The water agency plans to ask the Federal Emergency Management Agency to pay 75 percent of the repair costs after the project is finished. The rest would be borne by State Water Project customers.

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