City of Kirtland, East Branch Chagrin River Restoration Stream Restoration Design-Build
- Lake County
- Streams: 650 LF
The Chagrin River Watershed Partners (CRWP) and the City of Kirtland sought a qualified design-build contractor to complete the design and restoration construction of a streambank stabilization project along the East Branch Chagrin River.
CRWP and the City applied for funding from the Ohio Environmental Protection Agency (Ohio EPA) Section 319(h) Nonpoint Source grant program to procure design-build services, in order to develop an innovative Natural Channel Design and streambank bioengineering approach to address significant channel impairments along the project reach.
While the impetus for the project was the protection of Wisner Road and adjacent infrastructure from rapid bank erosion, our restoration design is multi-faceted and will reestablish equilibrium conditions that efficiently transport water and sediment, reverse systemic erosion, provide enhanced ecological value, restored in-stream habitat, and fisheries, and improved site aesthetics. RES achieved this with a combination of strategically placed in-stream structures and innovative bioengineered bank treatments that replicate the natural stabilization processes in order to regain channel stability and restore the lost functions and values of a robust stream system.
Our approach relied on rebuilding the toe of the slope, prior to grading eroded banks back to a stable angle of repose. Bank reinforcement included the application of composite revetment, a layered bioengineered bank treatment of rock, geotextile, soil, and live woody cuttings. RES constructed the composite revetment in combination with two rock riffles to strategically direct flow, narrow and deepen the existing channel, and establish stable meander geometry. These structures act as a catalyst for deep center channel development, provide a localized reduction in shear stress, and lead to the development of stable streambanks, pool/riffle habitat, diverse bedforms, and in-stream habitat. Along an adjacent meander bend, a flood bench was reconstructed, using a combination of materials salvaged on-site. These materials included on-site rock and riprap, stream gravel, large timber, and woody debris to create a natural toe-of-slope treatment, called toewood revetment. Toewood revetment mimics the natural recovery processes in riverine systems and provides prime resting and feeding habitats for Salmonids. RES designed, permitted, and constructed the project, completed in June of 2020.