MANKATO — Spring flooding will leave the city of Mankato awash in repair bills — at least $750,000 and possibly well over twice that amount, according to estimates prepared in anticipation of a federal disaster declaration.
Much of the cost is related to debris removal and repairs at the city's riverside parks and trails, according to a report from City Manager Pat Hentges.
Recent rains on top of already soggy soils are only adding to the list, said Public Works Director Jeff Johnson, referring to landslides behind the Happy Chef restaurant.
"It's not just about the river," Johnson said. "We have saturated ground as well."
The biggest single estimated cost is $200,000 to deal with silt, driftwood and other debris at Land of Memories Park, which was nearly completely submerged by the overflowing Minnesota and Blue Earth rivers that border three sides of the park. Overall, it's expected to cost $307,000 to clear four parks and numerous trails of the silt and detritus left behind as the rivers return to their banks.
Another $335,000 will be needed for park repairs, ranging from $90,000 to fix the Minnesota River Trail to $5,000 to restore the archery range at Kiwanis Recreation Area. In that category, Land of Memories took the brunt of the flood damage, as well, including $23,000 to the electrical hook-ups at the campground's RV sites, $55,000 to the shower building, $25,000 to the Floyd Roberts building and a combined $40,000 to the garage, administrative building, trails and boat landing.
"The above estimated damages are expected to greatly increase once the flood waters recede," Hentges stated in a summary of the cost projections. "We are very concerned about the Minnesota River bank in Land of Memories as restoration and repairs could reach a million dollars."
That bank on the western side of the park has been an issue for years because of its proximity to one of Mankato's drinking water wells. When the local sales tax was extended in 2016, eligible future uses included up to $2 million for riverbank stabilization, primarily at Land of Memories Park.
"In addition, the access road to the campgrounds has been damaged beyond basic repair," Hentges reported. "Finally, we experienced a major sewer main break near Harley Davidson on North River Drive. We believe that the pipe separation occurred as a result of shifting soils on the former river bottom ground north of the levee."
A bypass of the sewer main was set up and no sewage was released into the Minnesota River, Johnson said. A project replacing the pipe was completed Wednesday, and the excavation demonstrated how saturated the ground was in the area.
"It was like quicksand down there," he said.
The current estimates are based to some degree on what was left behind by previous floods, according to Deputy City Manager Alison Zelms. The actual extent of the damage won't be known until river levels drop significantly — something that will be delayed at least another week by the recent rains.
Neither the riverbank erosion nor the sewer pipe damage was included in the initial estimate of flood damages, which totaled $752,000. The public infrastructure impacted by the flood would typically be eligible for federal disaster assistance if a disaster area is declared by President Trump. Gov. Tim Walz notified Trump on Monday that he expects Minnesota to easily meet the threshold for a disaster declaration but it will take time for the water to drop and the full damage to be assessed.
"Given that many communities are still fighting the floods and more time is needed to fully restore power in southern Minnesota, it will likely be several weeks before a PDA (preliminary damage assessment) can be properly conducted," Walz wrote in his letter to the president.
It's been a long wait for the Minnesota River to retreat. The river rose above flood stage of 22 feet March 20 and stayed there until April 6, spending 10 days above 25 feet. The river has now been above 20 feet for an entire month and is expected to remain above that mark for at least another week.
The National Weather Service recorded a crest for the Minnesota River in Mankato on March 22 of 26.24 feet, which would be the ninth highest river level on record. The recent rains are pushing the river higher again, and a predicted crest of 24 feet this weekend would be the 15th highest, according to NWS records.