Channel Migration Studies and Maps

Channel Migration Studies and Mapping

"The goal of Channel Migration Zone (CMZ) mapping is to provide a cost-effective and scientifically-based tool to assist land managers, property owners, and other stakeholders in making sound land use decisions along river corridors. Typically, projects constructed in stream environments such as bank stabilization, homes and outbuildings, access roads, pivots, and diversion structures are built without a full consideration of site conditions related to river process and associated risk. As a result, projects commonly require unanticipated and costly maintenance or modification to accommodate river dynamics. CMZ mapping is therefore intended to identify those areas of risk, to reduce the risk of project failure while minimizing the impacts of development on natural river process and associated ecological function. The mapping is also intended to provide an educational tool to show historic stream channel locations and rates of movement in any given area.

CMZ mapping is based on the understanding that rivers are dynamic and move laterally across their floodplains through time. As such, over a given timeframe, rivers occupy a corridor area whose width is dependent on rates of channel shift."  (Boyd and Thatcher, 2017)

Channel Migration Studies and Mapping have been completed for the major river systems in Gallatin County:

• East Gallatin River CMZ Report and Maps
• Gallatin River CMZ Report and Maps
• Jefferson River CMZ Report and Maps
• Madison River CMZ Report and Maps