Communities throughout Montana face unique challenges when living near rivers. The historic floods of 2011 are a good reminder of the need for a better understanding of the power of rivers and how they can change. The fundamental concept of Channel Migration Mapping is to identify the area that a stream is expected to occupy over a given time frame. The final map product shows where the river has been over the last 50-60 years and where, based on the historic information, it might move in the future. The results can be used to identify hazards to health and human welfare, as well as to enhance effective resource protection in dynamic riparian areas. Channel Migration Mapping can serve as a science-based tool to educate the public and help landowners and local decision makers make the best choices for citizens and resources.
The current Upper Missouri Channel Migration Mapping project has the following goals:
1. Develop Channel Migration Mapping for priority reaches of nine Upper Missouri Watershed rivers.
2. Provide educational opportunities on use of the mapping for local stakeholders.
3. Provide the resulting mapping data layers to local stakeholders, as well as archive the data sets at the State Library.
This is a large undertaking and is unprecedented in Montana and the United States. The Ruby Valley Conservation District managed the current project scope. DTM, a contractor knowledgeable in Channel Migration mapping and the unique geology, geomorphology, and regulatory climate of Montana, was hired to perform the actual work. The project area includes the mainstem rivers of the Upper Missouri River watershed upstream from Three Forks, MT. This includes 700 miles of rivers; Red Rock, Big Hole, Beaverhead, Jefferson, Boulder, Madison, East Gallatin, and Gallatin; supporting 13,000 square miles of watershed. Seven counties and eight conservation districts are included in the project area.