(NewsNation) — The Rapidan Dam in Blue Earth County, Minnesota, is in "imminent failure condition" according to authorities, who have warned residents to be prepared to evacuate.
No evacuations have been ordered yet as the state has faced serious flooding with the possibility of more rain in the forecast.
Water appeared to have formed a path around the dam, but according to the Blue Earth County Sheriff's Office, the dam was still intact. The office warned it was not clear if the dam would continue to hold.
Water was flowing at a rate of more than 30,000 cubic feet per minute, the equivalent of 20 Olympic-sized swimming pools.
The city of Mankato, Minnesota, reported the river was currently at 28 feet, with the dam built to hold 39.5 feet. Should the dam fail, there could be a surge of river water up to 2 feet.
An Xcel Energy substation at the dam has already been washed away, affecting power for around 600 residents.
The dam was built in 1910 and has been weakened by repeated flooding over the decades. A 2021 report recommended repair or removal, but Blue Earth County said on its website there was no danger to the public.
Residents in the area were told to be prepared for possible evacuation if the dam fails.