Authorities issue dire warnings amid imminent California dam collapse | 12 Feb 2017 | Authorities ordered the evacuation of several northern California towns as a rapidly eroding section of a dam appeared on the verge of collapse. "Immediate evacuation from the low levels of Oroville and areas downstream is ordered," the Butte County sheriff's office posted on Facebook Sunday night. "Operation of the auxiliary spillway has lead to severe erosion that could lead to a failure of the structure. Failure of the auxiliary spillway structure will result in an uncontrolled release of flood waters from Lake Oroville." The evacuation warning was "NOT a drill," the sheriff's office added.