Logan River Restoration: A Conceptual Design for the Third Dam Area, Cache County, Utah

The Logan River downstream of Third Dam has been impacted by several past and present disturbances. Channel instability, eroding river banks, and reduced streamside vegetation have diminished the extent and quality of riparian-wetland areas and aquatic habitat. Studies were performed to determine if channel restoration would benefit the entire riparian corridor through holistic channel restoration practices. Existing conditions were determined for hydrology, morphology, sedimentology, riparian-wetland resources, and fish habitat. The conceptual design developed to restore the stream channel and floodplain would: restore four large meanders so natural fluvial processes could be used to re-establish riparian-wetland areas; increase channel length, channel sinuosity, radius of curvature, and meander length; stabilize eroding streambanks and eliminate the processes causing channel widening; and reduce pool-to-pool spacing to improve instream fish habitat. Approximately 0.53 hectare of riparian-wetlands and 0.23 hectare of aquatic habitat would be restored.