North American Construction was contracted by the property owner to perform an emergency bank stabilization to protect and replace a failing bank that was jeopardizing the stability of the house and septic system at the top of the bank. The owner had previously lost approximately 40 feet of bank prior to this stabilization project. North American was able to provide a cost effective and permanent solution for the property owner.
The project has approximately 415 LF of bank stabilization consisting of a terraced concrete lunker wall keyed in constructed from the OHWM to top of bank with permanent vegetation established on the terraces and broken concrete placement at the upstream and downstream ends of the wall for further stabilization. Additionally the gravel construction shelf at the toe of the wall was pushed in slightly to more closely match the upstream and downstream bankfull widths. The toe was stabilized with clean riprap to prevent undercutting of wall during highflow events.
Restoration efforts implemented upstream to offset the impacts resulting from the wall installation included native bank re-vegetation utilizing woody and herbaceous vegetative components and biodegradable erosion control blanketing through the reaches where stream substrate was removed. Additionally two grade control riffles were installed. The removed stream substrate was re-incorporated into the habitat structures and associated run. The access road was re-vegetated with herbaceous and woody vegetation for permanent stabilization.