IMA was contracted by the Lemhi Regional Land Trust to design a plan to stabilize a 450 ft section of eroding bank on the Salmon River.  The Salmon River experiences very high spring flows which have been eroding this bank at a rate of 5-10 ft per year.  Both the client’s goals and the permitting climate required a bioengineered solution.  A full topographic survey of the project reach and the adjacent river was performed to provide data for engineering analysis.  Hydraulic modeling, HEC-RAS, and reference reach comparisons drove the design process.  The design utilized bank re-sloping, willow transplants, and coir wrapped soil lifts for short term bank stability. Long term bank stability and riparian function was addressed with a variety of containerized native woody plant species. A full construction bid package was generated with comprehensive installation specifications and material quantities.

After completing the design and construction ready plan set for the Lemhi Regional Land Trust, IMA was chosen through a competitive bid process as the installation contractor.  IMA partnered with a local excavation firm and procured local labor to complete the project.  450 linear feet of streambank were successfully restored and revegetated with native plant species. The entire project area was fenced to exclude livestock and protect the restoration investment.