Hungry Canyons Alliance: Streambed Stabilization in Western Iowa

The Hungry Canyons Alliance (HCA) was formed locally to provide financial and technical assistance for streambed stabilization projects in the 19 counties of the deep loess region in western Iowa. Stream straightening and land-use changes, coupled with the erosive nature of loess, caused streams to downcut and widen, undermining bridges, farmland, and utility lines. The most efficient and affordable way to stop channel degradation has proven to be the construction of grade control structures (GCS). GCS allow a drop in stream elevation in a controlled setting, prevent further degradation, decrease sediment loads and turbidity, and increase water quality. With over 750 GCS of all types in western Iowa, western Iowa has been referred to as a "laboratory" for GCS design. The HCA has conducted research on GCS design and fish passage, the use of directional drilling to control gully erosion, the use of scrap tires in GCS, knickpoint migration, and aerial stream classification.