Minnesota Department of Transportation (MnDOT) officials say it will be weeks — and likely months — before a washed-out stretch of Hwy. 23 in Carlton County will reopen.

Nearly 10 inches of rain socked the Pleasant Valley and Holyoke areas about 15 miles southwest of Duluth Saturday night into Sunday morning, and the deluge unleashed a powerful current that swept away a 300-foot section of the highway and left piles of asphalt and twisted guardrails in its wake.

Meanwhile, the agency is bracing for more damage further south. MnDOT shut down Hwy. 48 early Tuesday after water from the St. Croix River overtook the highway connecting Hinckley, Minn., with Danbury, Wis.

A dam holding back water on the Tamarack River in Wisconsin failed late Monday. The breach sent water downstream heading for the St. Croix River and the rising river overtook Hwy. 48 early Tuesday.

"There is no doubt we will have hundreds of feet of lost pavement," said Chris Cheney, a maintenance superintendent in MnDOT's northeastern district.

More than 10 inches of rain fell across northeastern Minnesota and northwestern Wisconsin over the weekend. Several rivers jumped their banks and sent torrents of water gushing down roads and hillsides. The Nemadji River rose to a record-high 30.3 feet in Superior, Wis., and sprawled far out of its banks all along a path from Carlton County to Lake Superior.

When the water finally recedes, road maintenance departments will face some tough decisions and hefty repair costs.

Carlton County Sheriff Kelly Lake said damage to county-owned roads already was approaching $350,000, and assessments were still coming in.

MnDOT will face a bigger bill. The cost to repair Hwy. 23 could run from $400,000 on the low end to much more.

"We're talking big dollars here," Cheney said

Cheney said that will depend on how badly damaged a culvert under Hwy. 23 is. If it can be replaced, the road could be open in a few months. If it can't be, and a bridge needs to be built, "we'll be lucky to have it open before winter," he said.

MnDOT set up an emergency command team on Tuesday to tackle the problem and brainstorm solutions for getting the highway open as quickly as possible without compromising safety.

"This is a key thoroughfare," Cheney said of Hwy. 23. "We need to expedite the process."