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 simplest way for you to access the flood hazard data,
including the NFHL, is through FEMAs Map Service Center (MSC).If you want to explore the current digital effective flood hazard data in a map, the best tool to use is the NFHL Viewer. From the NFHL Viewer, you may view, download, and print flood maps for your location.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 Flood Hazard Products and Services which provide coverage for those areas.A list of the types of data available in the NFHL and information about other ways to access the NFHL may be found in the NFHL GIS Services User Guide.If you need more information about individual tables in the NFHL, the FIRM Database Technical Reference, found at FEMA’s Technical References, includes those details.For step-by-step instructions on how to read a flood map, you may view the How to Read a Flood Insurance Rate Map Tutorial.For more information, please visit the FEMA Flood Map Service Center.