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National Flood Hazard Layer

The National Flood Hazard Layer (NFHL) is a geospatial database that contains current effective flood hazard data. FEMA provides the flood hazard data to support the National Flood Insurance Program. You can use the information to better understand your level of flood risk and type of flooding.

The NFHL is made from effective flood maps and Letters of Map Change (LOMC) delivered to communities. NFHL digital data covers over 90 percent of the U.S. population.  New and revised data is being added continuously. If you need information for areas not covered by the NFHL data, there may be other FEMA products which provide coverage for those areas.

Accessing the National Flood Hazard Layer

Map Service Center

Access localized National Flood Hazard Layer data by searching FEMA's Map Service Center.

FEMA's Map Service Center

NFHL ArcGIS Viewer

Or you you may view, download, and print current local digital effective flood hazard data in an ArcGIS map.

NFHL Viewer

In the NFHL Viewer, you can use the address search or map navigation to locate an area of interest and the NFHL Print Tool to download and print a full Flood Insurance Rate Map (FIRM) or FIRMette (a smaller, printable version of a FIRM) where modernized data exists. Technical GIS users can also utilize a series of dedicated GIS web services that allow the NFHL database to be incorporated into websites and GIS applications. For more information on available services, go to the NFHL GIS Services User Guide.

You can also use the address search on the FEMA Flood Map Service Center (MSC) to view the NFHL data or download a FIRMette. Using the “Search All Products” on the MSC, you can download the NFHL data for a County or State in a GIS file format. This data can be used in most GIS applications to perform spatial analyses and for integration into custom maps and reports. To do so, you will need GIS or mapping software that can read data in shapefile format.

FEMA also offers a download of a KMZ (keyhole markup file zipped) file, which overlays the data in Google Earth™. For more information on using the data in Google Earth™, please see Using the National Flood Hazard Layer Web Map Service (WMS) in Google Earth™.

Draft National Flood Hazard Layer

The Draft National Flood Hazard Layer is for early awareness of possible changes to regulatory flood map information. Until the data becomes effective and it appears in the National Flood Hazard Layer, the data cannot be used to rate flood insurance policies or enforce the federal mandatory purchase requirement.

Making Official Determinations

The NFHL Database and GIS Services can be used in maps or application that combine the NFHL flood hazard data with basemaps and other reference data from other sources. However, to use the NFHL data for official purposes, you are responsible for making sure base map data meet FEMA’s accuracy standards and the locations depicted are interpreted properly. The NFHL Viewer provides a default base map that meets the minimum standards.

For the specifics of FEMA’s policy on the use of digital flood hazard data for NFIP purposes, see standards 147, 148, 149, 605, and 606 in the FEMA Policy Standards for Flood Risk Analysis and Mapping.

National Flood Hazard Layer Resources

NFHL GIS Services User Guide
Lists types of available data.

Technical References
The FIRM Database Technical Reference has information about NFHL about individual tables.

GIS Web Services for the FEMA Flood Hazard Data
Geared toward experienced GIS users.

How to Read a Flood Insurance Rate Map Tutorial
For step-by-step instructions.

NFHL Status
Current status of NFHL database services and data.

Using the National Flood Hazard Layer Web Map Service in Google Earth™
Includes information on how to download and use.