RAPIDAN — Authorities say the Rapidan Dam, under intense pressure from days of torrential rain and collected debris, is in “imminent failure condition.”
“There was some debris that got up against the dam, and that caused the water to find a new path around it and cut over to the west over to where The Dam Store is and the residence that’s down there,” said Chief Deputy Paul Barta of the Blue Earth County Sheriff’s Department from the scene Monday morning. “And it basically eroded away the west side of the dam and created a new path through there. It’s taken a substation for the power plant into the river.”
Barta said authorities have notified residents downstream from the dam about the potential danger.
“We’re deeming it as an imminent threat, just because none of us are hydrologists and don’t really know; there’s a lot of variables with this,” Barta said. “It’s pretty significant.”
A Blue Earth County press release said, “Public works, emergency management and sheriffs offices are implementing steps outlined in the Rapidan Dam Emergency Action Plan for Imminent Failure of the Dam including notification of potentially affected residents, impacted regulatory agencies and other local agencies.”
If the situation were to worsen, Barta said they’d increase efforts to notify residents and businesses downstream. They cannot, however, force anyone to evacuate.
“In the state of Minnesota, law enforcement cannot mandate an evacuation,” he said. “We cannot tell people they are required to leave their private property. People have the individual right to make the assessments if they want to stay or leave. So we make a recommendation, but we can’t force them.”
The debris that gathered near the dam made an already dicey situation even worse, causing the river to backup and reroute itself around the dam, perilously close to the beloved Dam Store.
The jam caused power outages early Monday. Xcel Energy’s outage map showed 579 impacted customers in the Mankato, Lake Crystal and Good Thunder service areas as of 10:30 a.m.
Debris remains packed hard against the dam, but Barta said it would be too dangerous to attempt to remove it. He recalled the 2014 incident where Michael Struck was attempting flood-water debris removal in Seven Mile Creek. The strong current tipped the backhoe Struck was operating, and Struck was pulled under and through a culvert.
“Trying to clear some of that stuff out can be just as problematic as trying to let let some of it wash away,” he said. “We’ve been fortunate none of it’s been been breaking up and flowing down river. Trees and things like that haven’t created an issue yet.”
The city of North Mankato has declared a flood emergency. In a press release issued this morning, the city said, “Beginning at 9:30 a.m. on Monday the Lookout Drive and Lee Boulevard intersection will be closed due to City crews building a temporary earth wall levee in this area. This intersection will be closed until further notice.”