The GEG-105 Physical Geography: Earth System Science course visited a former lake in Nicollet County yesterday. Whereas once huge expanses of southern Minnesota were covered with wetlands, an estimated 90 percent of these have been drained. With the addition of tiling to drain excess water, these former wetlands are highly productive crop land. Drainage of wetlands began in the late 1800s. Some wetlands, like Nicollet County’s Swan Lake, the largest “prairie pothole” in all of North America, were considered too big or too expensive to drain.
Wetlands provide many ecosystem services–filtering water, slowing runoff to the Minnesota River, and providing habitat for feeding, breeding and migrating species–as well as the services of beauty and recreation. Current regulations stipulate that any wetlands that are removed must be replaced elsewhere on the property at double the size.
Preservation of wetlands and the need for productive cropland continue to be contentious issues today. Certainly the changing land use has had a major impact on the landscape of our area as well as the economy, wildlife habitat, ecosystems, and hydrology.