Role of Depressions and Wetlands on Water Retention and Surface Flows in Blue Earth County, Minnesota

University of Minnesota/Satish Gupta

There is a pervasive belief that drainage of agricultural lands has drastically increased flows in the river of the Minnesota River Basin, which in turn has increased river bank sloughing and thus higher sediment loads. However, research has yet to establish if this is true and what volume of water the landscape can hold if it were not drained.

Using Light Detection and Ranging (LiDAR) elevation data, this research will quantify the potential volume of water that landscape depressions in Blue Earth County could hold provided there was no drainage and the excess water that may reach rivers at several precipitation probabilities. This research will establish a maximum baseline surface water retention capacity of Blue Earth County and consequently river flow reductions at various precipitation probabilities provided the depressions had not been drained.