The purpose of this page is to define Alluvial Fan Flooding, a commonly used term in floodplain management.
Flooding occurring on the surface of an alluvial fan or similar landform which originates at the apex and is characterized by high-velocity flows; active processes of erosion, sediment transport, and deposition; and unpredictable flowpaths. Alluvial fan flooding is depicted on a Flood Insurance Rate Map (FIRM) as Zone AO, with a flood depth and velocity.
- IS-9 Managing Floodplain Development Through The National Flood Insurance Program (NFIP) (Page 1-14) and Regulatory Standards (page 6-28)
- CRS Commentary Supplement for Special Hazards Credit