Where once stood a lake Posted on May 19th, 2010 by

Professor Emeritus of Geography, Dr. Bob Moline, stands at the shoreline of a former 1300-acre lake, Timber Lake, in Nicollet County. Numerous attempts were made to drain the lake before it was successfully drained in the mid-1950s.

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.

Drain tiles in fields collect excess water, which is drained to a series of county ditches. These ditches ultimately drain to small streams, like Roberts Creek and Seven Mile Creek, which empty into the Minnesota River.

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.

The natural surface drainage of Nicollet County has been greatly expanded through the addition of ditches and drain tile. Note the surface drainage channels (ditches) that tend to turn at right angles compared to the patterns of naturally occurring streams.


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