Published by:
University of Wisconsin Land Information and Computer Graphics Facility, Wisconsin Sea Grant
Produced by the University of Wisconsin Land Information & Computer Graphics Facility and the Wisconsin Sea Grant Institute, the building setback calculator and the stable slope angle calculator are web-based tools intended to inform users who are making decisions in regards to the development or purchase of property along the bluff top.
By collecting and inputting data on the structure life (as determined often times by county or state regulations), and the height, current slope angle, estimated stable slope angle, and the estimated recession rate of the bluff, the building setback calculator determines how many feet landward of the bluff's edge it is safe to build or purchase a property.
The stable slope angle calculator allows users to input data on their bluff height (ft), current bluff angle (deg.), and stable bluff angle (deg.) based on soil type, to estimate the distance landward from the edge of the current bluff that it would need to erode in order to at a "stable" slope angle. It is in this way that the tool can be used to determine a baseline estimate for a safe setback distance.
Both tools were designed to be used along the western shore of Lake Michigan and Lake Superior, however, they can still be used to provide a rough estimate of safe setback distances from coastal bluff elsewhere in the Great Lakes. This tool should not be used in lieu of a constulting engineer. These resources are located on the same webpage and can be navigated to by clicking on links to each tool on the homepage.