The project addressed 2,710 feet of highly eroding stream bank with approximate bank heights ranging from 5 – 6 feet.  The project location had unique challenges including: dramatic stage variation, boat wakes, muskrats, beaver, wave action from wind, ice, no native plant community, and sandy soils.  The project design goals were to: 1) use a systematic approach to prescribe bio-engineered treatments and 2) to stabilize three eroding banks on the lower Henry’s Fork River using live, rooted vegetation to establish a diverse native plant community prior to spring flood flows.  To develop the design, we used the following methods: 1) survey bank profile and channel cross-sections, 2) create topo map and HEC-RAS model, 3) collect hydrologic data from nearby USGS gauging station, 4) calibrate model with surveyed water surface elevations and generate hydraulic parameters for each reach, 5) identify additional forces that may be causing erosion, 6) develop stage-discharge-duration analysis, and 7) prescribe treatments based on project goals, shear stress tolerances and plant species that match the hydrograph.

Before - bank is eroding and unstable

Before - bank is eroding and unstable

After - bank has been re-sloped and is held in place by many rows of planted willows

After - bank has been re-sloped and is held in place by many rows of planted willows