Residents near Oroville in US state of Northern California were evacuated after a spillway appeared in the tallest dam of the United States. The Oroville Dam is in the state of imminent collapse.

Authorities issued an immediate warning stating that a crumbling auxiliary spillway on the Lake Oroville Dam could completely collapse, which would mean that floodwaters of gigantic proportion will be unleashed into the rural communities.

Through Twitter, the California Department of Water Resources said that the spillway was predicted to fail within the next hour, prompting emergency response for authorities to evacuate neighbouring areas. Fortunately, the spill remained intact for more than four hours, enabling helicopters to drop rocks into the lake to fill the gouge.

Travel alert has been issued towards all travelling toward Oroville. The evacuation order prompted thousands of people to turn to the evacuation centres set up at fairgrounds in Chico, California.

Oroville Dam is an earthfill embankment dam on the Feather River east of the city of Oroville, California, in the United States. At 770 feet (230 m) high, it is the tallest dam in the US and serves mainly for water supply, hydroelectricity generation and flood control. The dam 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), and is located in the Sierra Nevada foothills east of the Sacramento Valley.