Alluvial Fan Inventory – Wasatch and Oquirrh Mountains

Problem

  • Alluvial fan landforms pose a unique flooding hazard that is not found on non-fan landforms
  • Identify alluvial fan landforms along the Wasatch Range and Oquirrh Mountains

Approach

  • Collection of large data sets including geologic mapping, topographic mapping, historical aerial photography, FEMA SFHA mapping, flood hazard mapping, and landslide/debris flow mapping
  • Identify alluvial fan landforms from the collected data
  • Field investigate selected landforms

Solution

  • The study resulted in the identification of nearly 400 alluvial fan landforms
  • 254 classified as High Hazard, and 144 classified as Moderate Hazard
  • GIS dataset was created for use by state, county, and local agencies when evaluating flooding hazards in their jurisdictions, or when creating/revision FEMA SFHA mapping

Location

Box Elder, Cache, Davis, Juab, Salt Lake, Tooele, Utah, and Weber Counties, Utah

Client

Utah Department of Public Safety

Project Leads

Mike Kellogg