Flooding impacting New Ulm, surrounding areas (2024)

Near Mankato the Rapidan Dam has been placed in imminent failure as rushing waters created a bypass alongside the dam, and fears continue it could collapse.

In New Ulm, the Cottonwood River water levels continue to climb, making it to 18 feet early Monday according to the National Water Center. The river hasn’t crested this high since 2018, when it peaked at 19.64 ft. New Ulm Police Chief Dave Borchert said Cottonwood Street and the bridge will continue to be closed for the next few days.

“The river is expected to crest at around midnight,” he said. “It will stay at that level for some time and then start dropping if everything goes right. From the predictions we’re getting, it should drop under 13 feet by the 28th and we would be able to work to open the road again.”

In the meantime, crews have worked to stop further flooding. Borchert said debris from fallen trees had begun to clog the river, so heavy equipment was brought in to clear the area.

Several tree trucks were stacked up along Cottonwood Street Monday. These trees were pulled from the Cottonwood River Monday morning by work crews hoping to prevent a logjam at the Cottonwood Bridge.Photo by Clay Schuldt

“Ultimately we were successful but we anticipate it could come up again,” he said. “When the trees are floating down the river because they were uprooted, there is a perfect storm because they ultimately get caught in the bridge and create a logjam which backs up the river.”

Borchert said fortunately there have not been any incidents on the river or near the flooding caused by it. He said people should take several precautions to ensure their safety.

“We ask them to stay off the river,” Borchert said. “Don’t go in there with kayaks, canoes, or any type of boat. Anything could change with the current. Don’t drive through standing water ever. A foot or more could move a small car and anything two feet or above can take SUVs.”

Borchert also advised people to stay off any body of water connected to the river, even backwater channels.

With the current situation at Rapidan Dam, he said it would have some impact on the Minnesota River of which the Cottonwood is a tributary. Beyond this, Borchert said the biggest impact in New Ulm would be prolonging the high levels on Cottonwood River.

Branches and other debris gathers at the Cottonwood Street Bridge following heavy weekend rains. Cottonwood Street and bridge have been closed since Saturday and is expected to remain closed for the next few days.Photo by Clay Schuldt

Highways 60 and 62 in Windom, 169, 22, 99, and 169 near St. Peter, and 169/60, 169 Southbound near Happy Chef in Mankato have all closed due to the flooding conditions. These have limited the options for people in these areas and commuters who travel back and forth for work.

MnDOT Assistant District 7 Engineer Scott Morgan said the road closures, combined with the roads already closed due to construction, have limited the options commuters have to get where they need to.

“There is more traffic as people try to access these limited routes,” he said. “We have construction projects as well with their detours, which have further impacts on the situation.”

Conditions were exacerbated by the failure at Rapidan Dam, where roaring waters eroded land and created a new waterfall bypassing the dam. With what he described as a controlled release, Morgan said he does not anticipate another major impact.

“We are watching it very closely and watching our bridges for debris,” he said. “We are in wait-and-see mode, we are seeing higher elevated flows of water downstream and are prepared to open and close roads as we need to. It’s hard to differentiate the impacts from Rapidan with the already elevated flows from the rain.”

Early Monday morning, spectators watched as water poured over the west side of the Rapidan Dam near Mankato. Photo by Brian Earl

Morgan warned drivers against looking for the quicker way, as many smaller roads have also flooded.

“When you come across detour signs, follow them,” he said. “Those are the best routes to follow. A lot of folks who ignore it go to the roads they know and they are flooded too. Even with traffic delays, the detours are still the best routes.”

With the spectacle taking place, many could be tempted to go out and see for themselves. Morgan said doing so could prevent crews from getting through efficiently.

“People are gawking, but with all the social media and video we suggest people stay home,” he said. “Don’t be a gawker. All it could do is make things worse for crews who need to work.”

For those commuting between New Ulm and Mankato, Morgan said they should continue to check https://511mn.org/. He said while nothing is closed in between the two cities, there will be delays.

“If it usually takes 30 mins, add 5-10 minutes on there because traffic is constrained.”

National Weather Service Meteorologist Tyler Hasenstein said Brown County can expect a tenth to a quarter of an inch Monday night. After this splash, he said there should be no precipitation until late Thursday and Friday.