What Is Flood Zone AE?

The Federal Emergency Management Agency determines flood risk for the United States, then creates maps to clearly show the geographic areas prone to flood. The designation AE indicates areas at high risk for flooding and provides the base flood elevations (BFEs) for them. The AE designation replaced the old designations of A1 to A30, known as the numbered A zones.

An area designated AE presents a 1 percent annual chance of flooding. This area is more commonly referred to as the base flood area or the 100-year flood plain. Because flood zone AE is prone to flood, property owners with mortgages from federally regulated lenders in these zones must buy flood insurance if they live in a community that participates in the National Flood Insurance Program (NFIP).

Using detailed hydraulic analysis and modeling, FEMA determines the base flood elevation (BFE), which is the predicted flood water elevation above mean sea level. Habitable areas of any new construction must begin above this level. For instance, if a property falls within an AE zone with a BFE of 5 feet, the first habitable floor must be above 5 feet. Habitable means floors with living areas on them.

FEMA provides access to communities' Flood Insurance Rate Map (FIRM) or Flood Hazard Boundary Map online via its Map Service Center. Each community's planning department will also have a floodplain map. Sometimes the maps conflict. In this case, compare the locations of the floodplain and the dates of each map. Use the most current map.

A community may legally mandate additional restrictions to development or construction within its floodplain beyond those set by the NFIP. Your local planning office sets the zoning ordinances for flood zone AE, as well as all other flood zones. This office will inspect new construction or require evidence to ensure principle structures adhere to both NFIP minimum standards and any higher standards set by the community.

The U.S. Congress gave FEMA and NFIP the power to create and administer the floodplain mapping, create regulations and create the flood insurance program by passing two acts: The National Flood Insurance Act of 1968 and the Federal Disaster Protection Act of 1973. According to the 1968 Act, the impetus for the law was a series of floods and mudslides that claimed lives and property. Congress recognized that current urban planning practices weren't discouraging building in the floodplains leading to increased risk of loss of life and that disaster relief benefits could not adequately cover property losses.