Stillwater River, Montana

Southcentral Montana experienced extreme flooding in the spring of 2022 and WET was soon hired to scope out the permitting needed for a stream restoration job at the Stillwater Mine. Soon thereafter, WET was hired for both the design and oversight of the restoration. The project began late summer 2022 and included the design, construction oversight, and surveying and was completed in May of 2023. WET conducted a hydraulic analysis for several priority areas on the Stillwater River to determine the Base Flood Elevation (BFE) to determine the appropriate riprap size and gradations. Our efforts were crucial in getting multiple riprap designs put together within a very small timeline to complete the project. We utilized the United States Army Corps of Engineers HEC-RAS modeling software to assist in determining stream power and scour depth as part of the streambank stabilization design.