Chehalis Basin Reach-Scale Design
While walking 125 miles of the Sand Creek and Credit River (MN) during a watershed-level assessment, we identified over 200 restoration projects and ranked them on a 1-11 scale. Picha Creek ranked at the top for restoration potential. Increased rainfall, tilling and development pressures in the upper watershed were leading to channelization and resulting in incisions up to 10 feet. Significant sediment loads were also being released into the system, with no sign of equilibrium.
Inter-Fluve completed restoration projects on Picha Creek and nearby Porter Creek. For Picha, we had two options: raising the channel bed or lowering of the adjacent floodplain. Ultimately, we opted for a combination approach. A cobble and gravel riffle pool channel was created, and adjacent sand and sandy loam soils were used for channel fill to encourage infiltration and increased baseflow. In total, 3,000 feet of channel was restored. Only a few months after construction, the project received a 100-year storm and suffered no ill effects. Completed 2011