Musselshell River Floodplain Study Phase 1

The Montana Department of Natural Resources and Conservation (DNRC) contracted Pioneer Technical Services, Inc. (Pioneer) to conduct a bathymetric survey, hydraulic structure assessment, and hydrologic analysis for the Musselshell River Floodplain Study – Phase 1. This first phase of the Musselshell River floodplain study provided the groundwork for scoping and completing future floodplain mapping projects throughout the Musselshell River corridor. Pioneer completed the following for the Project Phase 1 activities:

Structure and bathymetric survey for a 10-mile reach near Roundup, Montana

  • Surveyed 4 bridges and 2 diversions structures.
  • Completed a bathymetric river survey, 73 cross sections surveyed (approximately 7 per mile).
  • Integrated bathymetric data into light detection and ranging (LiDAR) topography digital elevation models (DEMs).

Field reconnaissance and hydraulic structure assessment

  • Covered 335 mile extent of Musselshell River.
  • Assessed 87 structures.
  • Compiled in Geographic Information System (GIS) geodatabase.

Hydrologic analysis

  • Covered 335-mile extent of Musselshell River.
  • Conducted flood frequency analysis for 49 flow change locations (8 gaged, 41 ungaged).

All work was conducted to meet Federal Emergency Management Agency (FEMA) standards for detail level analysis.