Water pours down Oroville Dam spillway as reservoir rises following big storms

It’s a sight that usually means California is having a good winter and water supplies are healthy.

This week, operators at Oroville Dam, the tallest dam in the United States, which holds back California’s second-largest reservoir, opened the spillway gates and began releasing billions of gallons of water down the massive concrete spillway into the Feather River below.

The reason? It’s not to waste water. But to prevent potential floods.

Like many reservoirs in California,...