Streambank reconstruction design process, Silver Bow Creek, Montana

Significant lengths of streambank and floodplain of Silver Bow Creek in Southwestern Montana have been impacted by large-scale transport and overbank deposition of mining wastes from historic mining areas. Aggredation and braiding of the waterway and/or the relative lack of vegetation resulting from the sulfide mine wastes impaired the stream system. Natural adjustment of the stream channels over 100 years have improved the function and stability of the stream. The channel has incised, a significant percentage of the streambanks have developed stabilizing vegetation, and the floodplain is functioning appropriately. However, additional reclamation is required to meet remediation objectives and Superfund requirements. Appropriate stream channel and streambank design addressing these significant challenges included evaluation of field-scale streambank demonstration projects and focused on working with and maintaining the stability of the existing stream system along with streambank bioengineering/reclamation techniques at select locations rather than imposing a completely re-engineered design.