By Forrest Adams

Three of the Minnesota River crossing options would potentially have a direct impact on Seminary Fen, located in Chanhassen.

Seminary Fen harbors 90 acres of rare calcareous fens and includes eight rare plants, including twig rush and marsh arrow-grass.

A calcareous fen is the most protected type of wetland in the state. Calcareous fens are peat-accumulating wetlands that are dominated by groundwater and have specific chemical characteristics. The ground is continuously moist, and fens are kept continuously wet and cold by their groundwater supply. The groundwater that feeds fens also contains a certain amount of dissolved calcium and magnesium for specific and often rare hydrophytic plants.

The subject of how possible Minnesota River crossing might affect Seminary Fen came up during a work study session following the July 23 Chanhassen City Council meeting, and all councilors were in agreement that City Manager Todd Gerhardt should oppose any river crossing that would require a road to pass over Seminary Fen.

Hannah Dunevitz, plant ecologist with the ecological resources division of the DNR, works with local communities to protect natural areas, like the fen. She agreed that a road crossing over Seminary Fen “would have a huge impact,” due to salt and storm-water runoff, as well as shade that would be created over the vegetation, though she credited MnDOT for funding “thorough, hydrological surveys” of the area.

“It would cause direct disturbance of Seminary Fen,” she said.

DNR hydrogeologist Jeanette Leete was blunt in her response to a road crossing being considered over Seminary Fen, but she expressed understanding.

“I think it would be the absolute, most stupid thing a person could do,” she said. “But we need to wait for the process to work. All of us with niche interests are going to try to defend our interests. That’s why the process is important. The process ranks the concerns for all the professionals and ranks which option should be chosen. I have no right to expect that my opinions should be valued any more highly than the opinions of others.”

Read more about Seminary Fen in this week's print edition of the Chaska Herald.

Correspondent Forrest Adams can be reached at fadams@swpub.com.