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Flood Insurance Rate Maps (FIRMs) and
Digital Flood Insurance Rate Maps (DFIRMs)

Since the 1970's, FEMA has been creating, storing, and updating flood hazard maps for communities participating in the National Flood Insurance Program (NFIP). The resulting Flood Insurance Rate Maps (or the current digital products, Digital Flood Insurance Rate Maps), show areas subject to flooding based on historic, meterological, hydrologic, and hydraulic data, as well as land use conditions and flood-control structures.

The maps display 100-year (1 percent annual chance) and 500-year (0.2 percent annual chance) floodplains, base flood elevations, floodways, engineering cross sections, and related features, over a set of standard base map features. They comprise the primary tool for state and local governments to mitigate the effects of flooding in their communities.

Visit the FEMA Map Service Center for a general description of the special flood hazard area zone designations. More detailed information on each zone designation is available here.

Click on the county of interest to determine the status of map revisions for that county.

A tutorial on reading and understanding Flood Insurance Rate Maps is available here.

Source:
www.fema.gov