Mankato neighborhood balks at tax hike to fix ravine drainage

MANKATO – An entire neighborhood is rebelling against a tax for improving drainage and erosion issues in a ravine that cuts through the area.

All 29 property owners in the city's Oak Ridge subdivision signed onto an appeal filed in June in Blue Earth County District Court.

In the appeal, the homeowners allege that they were improperly assessed by Mankato Township to cover the cost of improving drainage in the ravine in their west Mankato hilltop neighborhood.

"We're very frustrated," said Di Storvick, one of the residents. "We have asked all kinds of questions, and it seems they don't have any good answers.

"There is not anyone in my neighborhood who is going to slide into the ravine in the next couple hundred years."

In May, the township board levied a special assessment totaling about $478,000 against all the Oak Ridge properties for street repairs and ravine improvements. Each property owner's share is about $16,500.

In their appeal, the homeowners allege that the township failed to conduct a market assessment before levying the tax. They also claim that other homes outside their subdivision would benefit from the ravine project but are not sharing the cost.

The homeowners also allege that the township board lacks the authority to make the ravine improvement and levy taxes for it.

"It's very nontransparent, the communication is poor and we don't feel that the township has even remotely done their due diligence on this ravine repair," Storvick said. "We've been trying to get our roads fixed for quite some time now, and it feels like they're bundling it together and sneaking in this big [ravine] project."

Daniel Rotchadl, township board chairman, declined to comment, citing the pending appeal.

Mankato and North Mankato have been struggling with erosion issues in recent years. Judson Bottom Road in North Mankato has been closed since March, when a landslide strewed car-size boulders over a stretch of the roadway. Hwy. 169 was closed for several days this spring from mudflows that covered the road.

The entire Minnesota River Valley is unstable, said Phil Larson, head of the earth sciences program at Minnesota State University, Mankato. The valley was formed about 13,500 years ago when the melting of glaciers released a massive flood.

The dominant soil, called glacial till, is fine and powdery, making it prone to shift when saturated. And the entire area is crisscrossed by ravines.

"It's sort of a powder keg," Larson said of the shifting soil. "These ravines are moving. They're extremely active and extremely young in geologic time."

Larson and scientists from a number of Minnesota colleges and universities are in the midst of a three-year project to examine areas across Minnesota that are prone to landslides and rockfalls. With the state experiencing more frequent and severe precipitation linked to climate change, the danger is increasing, he said.

Every ravine is different, and Larson said he couldn't comment specifically on the Oak Ridge area.

But "it's inevitable that they're going to grow, they're going to have erosion," he said. "It's the nature of the beast."

The homes in Oak Ridge generally sit 100 feet or more from the ravine's edge, so they're probably in no immediate danger, he said.

"But," he added, "do you want to gamble?"

John Reinan • 612-673-7402