As part of its administration of the National Flood Insurance Program (NFIP), FEMA publishes flood hazard maps, called Flood Insurance Rate Maps, FIRMs. The purpose of a FIRM is to show areas that are subject to flooding and the risk associated with these flood hazards.
One of the important factors of a FIRM is a Special Flood Hazard Area (SFHA), which indicates the areas with a 1% or greater chance for flooding in any given year. These areas are also referred to as a 100-year floodplain.
Another important feature is to show the elevation of the 100-year floodplain. The floodplain elevation is called the Base Flood Elevation (BFE). BFEs are shown on FIRMS and in profile view in the Flood Insurance Study. This information is required for completing an Elevation Certificate, to flood proof a structure, and to determine a flood insurance premium.
There are flood zones throughout the City which are shown on the FIRM. These zones indicate the type of floodplains within the SFHA. The flood zones consist of Zone AE for a 100-year floodplain. Zone X for either a 500-year floodplain or an area outside the 500-year floodplain. Zone AO for overland sheet flow with depths of one to three feet, and Zone A for “non-studied” floodplains that have not determined a Base Flood Elevation.