FEMA floodplain maps include information about physical features of an area, such as roads and waterways, base flood elevations and depths. The maps also show Special Flood Hazard Areas, flood insurance risk zones, and areas subject to inundation by the 500-year flood.
FEMA's Flood Insurance Rate Maps show areas subject to flooding. The information shown on the maps is based on historical, meteorological, hydrologic, and hydraulic data. FEMA conducts engineering studies in flood-prone areas to determine the extent of flood risk. The information collected in these studies is used by FEMA engineers and cartographers to create flood maps.
Flood maps do not all follow the same format, however, there are two basic formats. The "Flat Flood Map" consists of one or more 11-inch by 17-inch pages with a cover. The "Z-Fold Flood Map" is a larger map with multiple panels that is folded like a highway map.
Several basic elements are included on every flood map, including the index map, panel, title box, legend, and standard symbols. The differences are due to improvements in flood map design since the program was originally implemented; design improvements are incorporated when maps are updated.
Copies of the flood maps, as well as the studies used to create them, are available through FEMA's Map Service Center.