Tennessee Dam Near Failure After Heavy Rain From Helene

The Nolichucky Dam in eastern Tennessee was on the brink of failure early Saturday and the authorities urged the residents of communities downstream to evacuate immediately, after extreme rainfall from Helene caused water levels in the area to rise to record levels.The National Weather Service office in Morristown, Tenn., said dam failure was imminent and flash flooding was likely to occur downstream.“If you are in low lying areas below the Nolichucky Dam you should move to higher ground immediately,” its alert said.“A breach could occur at any time,” said Elisabeth Thompson, a spokeswoman for the Tennessee Valley Authority, the dam’s operator, adding that potentially life-threatening flooding could occur as far downstream as Douglas Lake.A dispatch officer at the Greene County Sheriff’s Department said that there were a couple cracks in the dam and evacuations were ongoing early Saturday.By Friday night, water levels on the Nolichucky River rose 17 feet above the level recorded before the storm’s arrival, according to to the United States Geological Survey.A complete failure of the Nolichucky Dam would cause a wave reaching bridges in as little as 20 minutes, followed by crests arriving at each location soon afterward, the Weather Service said.

Flash flooding concerns prompted evacuation orders downstream from another dam in Tennessee on Friday.The Tennessee Emergency Management Agency warned of a breach of the Waterville Dam, near the border with North Carolina, but later said that it had not failed.Duke Energy, the Waterville Dam’s operator, said that it had all of the floodgates open and was passing water through the dam after “unprecedented flooding.”This is a developing story....