Niswander Environmental was contracted to design and oversee installation of in-stream structures to protect bridge abutments shared by two residential properties in Bloomfield Hills, MI. This section of the Rouge River had severely scoured an existing bridge to the point that its structural integrity was compromised. Prior to design, a site investigation was conducted to evaluate the existing conditions and severity of the erosion issues at hand.
An effective strategy to restore and manage this segment of river was designed in Summer 2007. Two in-stream habitat structures, known as cross-vanes, were installed to aid in dissipating energy and training stream flows into a defined thalweg that is directed away from the banks and existing bridge supports. Cross vanes not only direct stream flow away from the banks; they reduce erosion, prevent downcutting, and control streambed gradient. Additionally, these cross vanes provide increased fish and macroinvertebrate habitat by creating scour pools at the overflow convergence. This project was designed and managed by Niswander Environmental, and has received several accolades from the State as an innovative and successful stream restoration project.