2017 Oroville Dam crisis
Coordinates: 39°32′33″N 121°29′31″W / 39.5426°N 121.4920°W
In February 2017, Oroville Dam's main and emergency spillways were significantly damaged, prompting the evacuation of more than 180,000 people living downstream along the Feather River and the relocation of a fish hatchery.
In the midst of widespread rainfall during the 2017 California floods, damage to the dam's main spillway appeared on February 7, resulting in its closure as management tried to assess the extent of damage and ways to mitigate further damage. As storms dumped significant precipitation on the area, the lake level rose until it flowed over a concrete weir at the top of the dam's emergency spillway, despite the reopening of the damaged main spillway. As water flowed uncontrolled over the weir, headward erosion of the emergency spillway threatened to undermine and collapse the concrete weir, which could have sent a 30-foot (9 m) wall of water into the Feather River below and flooded communities downstream. A collapse never occurred, but the main spillway suffered significant damage and the bare slope of the emergency spillway was significantly eroded.
Oroville Dam, an important part of the California State Water Project, is an earthen embankment dam on the Feather River, east of the city of Oroville in Northern California. The dam is used for flood control, water storage, hydroelectric power generation, and water quality improvement in the Sacramento–San Joaquin River Delta. Completed in 1968, it is the tallest earthen dam in the United States, at 770 feet (230 m). It impounds Lake Oroville, the second largest man-made lake in the state of California, capable of storing more than 3.5 million acre-feet (4.4 km3). The adjacent Edward Hyatt Powerplant has six power-generating turbines with a total installed capacity of 819 megawatts (MW) of electricity.
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