A newly abandoned rail corridor over the Minnesota River between Scott and Carver counties, hailed as a vital new link in an emerging system of biking and hiking trails, is also a $6 million mess that someone is going to have to deal with, commissioners on the Scott side learned Tuesday.

The hope is that the Union Pacific railroad, which wants to walk away from the 5.6-mile spur, can be talked into covering more than $2 million of that -- and that others will step in later to pay for the rest.

"Our proposal is 'no cost to the county,'" said the Mark Themig, county's parks and trails program manager. But public works director Lezlie Vermillion cautioned that the public is stepping into the very situation from which the railroad is eager to withdraw, with one of the line's seven bridges already collapsed and at least one other not suitable for public use.

"We need to be up front about the fact that at some point there will be multimillion-dollar costs," she said. If all goes well, "we don't need to have to cover that; we can get outside funds."

The county board granted permission to enter negotiations with the railroad, accompanied by several other public bodies with a strong interest in the corridor for various reasons.

The rail spur, which runs roughly from the Renaissance Festival property near Shakopee across the river into the city of Carver and then downtown Chaska, was abandoned after a 2007 derailment caused the collapse of one of the bridges. The railroad only served one customer on that spur, so it wasn't worth it to replace the bridge.

The biggest news Tuesday was the price tag for acquiring the property and fixing up the bridges to the point where people could use the corridor.

Parts of the spur line date back to the 19th century, and an engineering study found that a lot of work will need to be done before it's safe to use.

The main river bridge, a 600-footer built in 1917, "is deficient and can't be used as a trail crossing," Themig said. "Piers have shifted, and it causes logjams on the river. It needs to come down."

But he said there's a lot of interest among public bodies in keeping the corridor together for various possible uses, including outflow from a proposed sewer plant serving future growth in Scott County. That could mean financial help in making the project work.

A Chicago attorney, experienced in railroad negotiations, is helping local officials and believes that the railroad can be brought around to donating the roughly $1.5 million property and covering other costs, Themig said. It would mean a tax writeoff, would release the railroad from the hassles of owning it and could result in favorable publicity.

Board members had some concerns. "How does this impact other trail projects in the county?" asked Board Chairman Jon Ulrich. "Is this going to take away from them?"

Senior managers assured the board that for now it's all about keeping a link intact, and that nothing need ever be spent to improve it unless a decision is made that it's worthwhile.

"We don't seem to have anything to lose by going forward," Ulrich concluded, and Themig agreed.

"Right now it's win-win," he said. "But we need to see how successful we are in negotiations. We need to stand firm. Union Pacific does need to deal with that bridge one way or another."

David Peterson • 952-882-9023