Detroit/Wayne County Port Authority
Many organizations collaborated with the Detroit/Wayne County Port Authority
in this demonstration and site stabilization effort, including members of the
Greater Detroit American Heritage Rivers Initiative, the Natural Resource Conservation
Service (NRCS) and NTH Consultants, Ltd, who provided technical support for
the design. The City of Detroit Recreation Department provided the site on Belle
Isle. Project staff applied for and obtained a permit, identified locations
for harvesting live and inert plant material, submitted
a request for proposals and selected a contractor.
Prior to the workshop, the contractor, Cameron Contracting of Wixom, Michigan, prepared the site by removing broken concrete and trash, sloped the soil and laid down a grass matting to protect the site from further erosion. Project staff obtained live plant materials several days before the workshop. During the workshop, participants learned about the techniques they were going to be employing in the field and shared insights from previous projects with which they had been involved.
The contractor cut back the eroded banks with a backhoe and excavated to provide a place for the geotextile fabric. Volunteers then installed live fascines, brush mattresses and vegetative geogrids above the rock toe to further stabilize the shoreline.
Fascines are bundled branches, usually willow or dogwood, that are tied together
with twine. Inert fascines were used along the shoreline, while live fascines
were used further up slope. Brush mattresses are made from live willow and/or
dogwood branches and are used in a similar fashion as erosion control netting.
The mattresses are secured to the slope with dead stout stakes. The vegetated
geogrid process involves placing rock riprap at the edge of the shoreline and
then creating steps up the slope of the shoreline using a geotextile mattress.
Live cuttings are placed in between each step.
Project staff, in partnership with many organizations, agencies and private
consultants, succeeded in demonstrating innovative soft engineering techniques
along the Detroit River. Through this process, Belle Isle visitors will learn
about the alternatives to hard engineering, as they are exposed to the aesthetically
pleasing shoreline of Lake Muskoday. The stablization of Lake Muskoday has also
enhanced the wildlife habitat along the lake. The Port Authority's long term
hope is that this project will inspire on large-scale and more efficient and
cost-effective shoreline erosion control methods along Detroit's Belle Isle
and the Detroit River as a whole.
Contact: John Kerr, (313) 331-3842