Minnetonka Shoreline Stabilization Project
The Lake Minnetonka Shoreline Restoration Project is classifying the shoreline around the lake according to its likelihood to erode, and by creating five demonstration sites of natural stabilization (bioengineering) to show homeowners and contractors how to work with a variety of shoreline conditions. The first demonstration site was completed in 2005 at the headwaters of Minnehaha Creek at Grays Bay. The remaining four sites were stabilized during the summer of 2009.
The classification portion of this project accounts for three factors:
- Fetch – The distance from the far end of the lake to the point on the shore being classified, as measured along summer prevailing winds. Summer prevailing winds around Lake Minnetonka are generally southeast to northwest, so fetch on the southeastern shoreline is usually zero. The fetch is highest across large bays on the northwest shore. Higher fetch indicates higher erosive potential.
- Slope – The pitch of the land immediately adjacent to the shoreline. Greater slope indicates higher erosive potential.
- Soils – Soils are classified according to their erodibility by the USDA NRCS, among others. Sandier, less cohesive soils, indicate higher erosive potential than clay and more cohesive soils.
MCWD combined each of these factors to classify all of the shoreline of Lake Minnetonka into four categories – High, Potential, Low, and Sensitive. "High” shoreline has the greatest potential for erosion, “Low” has the lowest, and “Potential” is indeterminate, meaning there were not enough data to classify it. “Sensitive” shoreline indicates the presence of a wetland.
The headwaters of the Minnehaha Creek at Grays Bay already serves as one of the five demonstration sites. MCWD will construct the other four sites on a variety of site conditions, ideally one on each of the four classification categories. These publicly accessible sites will serve as examples to homeowners and contractors who wish to construct bioengineered solutions to erosion problems on shorelines. They will demonstrate a variety of techniques, from mixed hard and soft armoring (interspersing vegetation with rock or other durable shoreline protection) to pure vegetative solutions, with plants running from the waterline up several feet out of the water. MCWD will direct anyone who asks about soft or green shoreline stabilization to these sites and will encourage local municipalities to do the same.