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SOUTH
FORK OF THE COEUR D’ALENE RIVER RESTORATION PILOT,
KELLOGG, IDAHO
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| South
Fork CdA River Before Restoration |
The South Fork of the Coeur d’Alene River has been heavily impacted for
more than 100 years by heavy metals mining, smelting, and milling. This impact
has significantly degraded the ecological and hydrologic system. As a result of
large scale mine tailings removals (250,000 cubic yards) on the one mile stretch
of river between Kellogg and Smelterville, the site was left in an unstable condition
with minimal vegetation and no fines or organic material on the floodplain. TerraGraphics
worked with the Idaho Division of Environmental Quality, EPA, Idaho Fish and Game,
and the BLM to develop a pilot restoration project for this reach. Hydrology was
developed using historic and present USGS gages near the site. Survey of the site
was completed using survey grade GPS and a robotic total station. From this data,
existing topography, cross sections, thalweg profiles, and water surface profiles
were developed. A HEC-RAS model was assembled to model current and proposed river
dynamics. Historic photos of the river allowed identification of stable nodes
through the reach and areas subject to braiding.
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| South
Fork CdA River After Restoration |
The emphasis of the project was on natural channel design with the use of stable
nodes and limited bank stabilization recognizing the fact that the reach is located
in the middle of a highly impacted system. TerraGraphics developed construction
plans and specifications and worked with the State of Idaho to select a contractor
for the project. In addition, TerraGraphics was responsible for construction direction
and assistance with material acquisition. Water quality impacts were monitored
throughout the project. Revegetation of the site emphasized the use of volunteers
to increase community support of projects in the region.
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