Hwy. 22 bridge closed due to flooding; Rapidan Dam in imminent failure condition

Highway 22 has become the latest route to St. Peter closed down due to flooding. At 11 a.m. Monday, the Minnesota Department of Transportation announced that Highway 22 between the intersections of Highway 169 in St. Peter and Shanaska Creek Road near Kasota was shut down to traffic. Drivers are advised to use Highway 169 as an alternate route.

Floods resulting from multiple days of heavy rainfall over last week have led to a series of road closures surrounding St. Peter. Since Friday night, the Highway 99 bridge has been blocked off on account of rising water levels on the Minnesota River. Both northbound lanes on Highway 169 at the north end of St. Peter were subsequently closed, and traffic has been redirected to the southbound lane for approximately two miles.

Though the River Valley enjoyed a drier Sunday and Monday, water levels on the Minnesota River have continued to accumulate. According to the National Water Prediction Service, water levels at Mankato rose over 10 feet since Wednesday and was last measured at 28.47 feet at 12:30 p.m. Monday. The river is expected to reach a near-historic level of 29.6 feet on Tuesday.

While water levels have continued to skyrocket, flooding incidents within city limits have remained minimal.

On Monday morning, the city of St. Peter responded to encroaching waters on the intersection of S. Front Street and Walnut Street by closing down the intersection. As of 2 p.m. Monday, the intersection remains the only road in St. Peter closed off due to flooding.

Public Works is also providing sand to residents and homeowners who wish to protect their property in the event of a flood. Sandbags can be obtained from the Nicollet County Sheriff’s Office lobby at 501 S. Minnesota Ave, while the sand itself is available at the drop-off site at 1128 Swift Street.

Rapidan Dam breached

A potential failure of the Rapidan Dam threatens to further exacerbate already high-water levels on the Minnesota River. Surging waters cutting around the west side of the dam have put he 475-foot structure into an “imminent failure condition,” according to an announcement by the Blue Earth County Sheriff’s Office Monday morning.

“We do not know if [the dam] 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,” the Blue Earth County Sheriff’s Office stated in a social media post.

If the dam fails, Blue Earth County officials anticipated river levels would swell up to an additional six inches to two feet, depending on the location downstream. The Blue Earth County Sheriff’s Office further wrote there was no evacuation order in place for Blue Earth County residents and anyone in immediate danger as a result of a potential dam failure has already been notified.

The conditions of the Rapidan Dam led the city of North Mankato to declare a flood emergency Monday morning and begin construction of a temporary earth wall levee at the intersection of Lookout Drive and Lee Boulevard.

Le Sueur County Emergency Management advised residents in low-lying areas of the Minnesota River Valley, such as St. Peter, Kasota, Le Sueur and Ottawa, to “closely monitor the situation and potentially evacuate.”