RDG assisted the Natural Resource Damage Program (NRDP) with development of a calibrated reach-scale model of the Upper Clark Fork River Operable Unit (CFROU) Reach A near Deerlodge, MT. The model provides information to support planning and design efforts for tailings removal and floodplain restoration in the Clark Fork River watershed. The reach-scale model will improve the understanding of the water surface elevations and discharges associated with floodplain connection and establishment of a functioning riparian corridor.
Data collection included vegetative and geomorphic indicators of bankfull elevations, channel cross sections, water surface elevations, pebble counts, and flow measurements. A calibrated hydraulic model was developed from surveyed cross sections and LiDAR floodplain topographic data. The model is being used to identify the approximate flood frequency and flow duration associated with the surveyed bankfull indicators. This will aid in establishing consistent and accurate design floodplain elevations for future remediation and restoration efforts. It will also provide information to support NRDP’s restoration planning and projects.