OVERSTEEPENING, MASS WASTING, AND STABILIZATION ON A CLAY SLOPE IN NORTHERN WISCONSIN

The red clay deposited in glacial lakes during the Late Wisconsin in the Lake Superior basin poses numerous difficulties to those living in the area. Bank instability and the slumping of clay creates engineering challenges and has negative impacts on aquatic habitats and in many areas, especially where the processes have been accelerated by human actions. A slumping bank along Deer Creek south of Ashland, Wisconsin has been actively slumping since railroad construction disturbed the area starting in the late 1800’s. Slumping on this slope can be severe during spring thaw and is a major source of turbidity in Deer Creek and downstream rivers. Several different mass-wasting processes take place on the slope depending on local vegetation, gradient, and water content of the clay. A joint study initiated by local citizens, the Wisconsin Department of Transportation, the Wisconsin Department of Natural Resources, and other interested organizations is being conducted to determine possible methods of bank stabilization. Signs are being installed along State Highway 13 so the site can serve as an educational resource for the public. Although this slope is just one of many such sites in the Lake Superior region, its stabilization is a step toward decreasing sediment loads in rivers draining into Lake Superior and heightening public awareness of the problem. It is also a example of how citizen action and cooperation among government agencies can work to decrease environmental impacts and increase public understanding.