A century-old concrete gravity dam on the Blue Earth River in Rapidan Township, near Rapidan, Minnesota, is in "imminent failure condition." This has sparked concern about America's aging infrastructure.
"We do not know if it will totally fail or if it will remain in place, however we determined it was necessary to issue this notification to advise downstream residents and the correct regulatory agencies and other local agencies," Blue Earth County Sheriff's Office wrote on Facebook.
For days, the sheriff's office has been monitoring debris build-up at the 114-year-old Rapidan Dam, located about ten miles southwest of Mankato. This puts the dam "in imminent failure condition." Heavy rains in recent days have raised river water levels.
"The river has significantly cut around the west side of the dam," Blue Earth County Sheriff's Office said. Also, an Xcel Energy substation at the dam has washed away.
The river level was already high from the large amounts of recent rainfall and moving fast when it diverted around the dam near the substation and flowed onto the bank," Xcel said in a statement, which NBC News quoted.
A 2021 assessment determined that the dam needed costly repairs or complete replacement. The county's website, however, warns that doing nothing "would pose a public safety concern and a tremendous liability."
The National Weather Service reported that the failure is expected to cause the Minnesota River at Mankato to crest just below major flood level early Tuesday.