100 Year Flood Zones

FEMA provides access to the National Flood Hazard Layer through a Web Map Service. The National Flood Hazard Layer is a computer database that contains FEMA's flood hazard map data. The data depict flood hazard information and supporting data used to develop the information. The primary hazard classifications are the 1 percent-annual-chance flood event, the 0.2 percent-annual-chance flood event, and areas of minimal flood hazard. Flood hazard and supporting data are developed using specifications for horizontal control consistent with 1:12,000-scale mapping. If you plan to display maps from the National Flood Hazard Layer with other map data for official purposes, ensure that the other information meets FEMA's standards for map accuracy. The NFHL data are from FEMA's Digital Flood Insurance Rate Map (DFIRM) databases. New data are added continually. The NFHL also contains changes to DFIRM data made by Letters of Map Revision (LOMRs). The service provides map images geo-referenced to the earth's surface using the North American Datum of 1983, Geodetic Reference System 80 coordinate system. The service also provides information that complements the National Flood Hazard Layer. In areas for which data are not available from the National Flood Hazard Layer, an older set of flood hazard data, named the "Q3" data, may be available. The service also provides information about the availability of flood data and maps, the national map panel scheme, river subbasins, and point locations for Letters of Map Amendment (LOMA) and Letters of Map Revision Based on Fill (LOMR-Fs). These complementary data are positioned less accurately than are the National Flood Hazard Layer data. The service organizes the data in layers. The layers display information at map scales appropriate for the data. Status information and river subbasins are displayed at map scales smaller than 1:300,000, regional overviews at map scales between 1:300,000 and 1:32,000, and detailed flood hazard maps at map scales of 1:32,000 and larger. The "Scalehint" item in the Capabilities file for the Web Map Service encodes the scale range for maps for a layer. Flood hazard areas identified on the Flood Insurance Rate Map are identified as a Special Flood Hazard Area (SFHA). SFHA are defined as the area that will be inundated by the flood event having a 1-percent chance of being equaled or exceeded in any given year. The 1-percent annual chance flood is also referred to as the base flood or 100-year flood. SFHAs are labeled as Zone A, Zone AO, Zone AH, Zones A1-A30, Zone AE, Zone A99, Zone AR, Zone AR/AE, Zone AR/AO, Zone AR/A1-A30, Zone AR/A, Zone V, Zone VE, and Zones V1-V30. Moderate flood hazard areas, labeled Zone B or Zone X (shaded) are also shown on the FIRM, and are the areas between the limits of the base flood and the 0.2-percent-annual-chance (or 500-year) flood. The areas of minimal flood hazard, which are the areas outside the SFHA and higher than the elevation of the 0.2-percent-annual-chance flood, are labeled Zone C or Zone X (unshaded). Flood Zone Definitions from the FEMA Flood Map Service Center. Data Download: https://www.floodmaps.fema.gov/NFHL/status.shtml

FEMA provides access to the National Flood Hazard Layer through a Web Map Service. The National Flood Hazard Layer is a computer database that contains FEMA's flood hazard map data. The data depict flood hazard information and supporting data used to develop the information. The primary hazard classifications are the 1 percent-annual-chance flood event, the 0.2 percent-annual-chance flood event, and areas of minimal flood hazard. Flood hazard and supporting data are developed using specifications for horizontal control consistent with 1:12,000-scale mapping. If you plan to display maps from the National Flood Hazard Layer with other map data for official purposes, ensure that the other information meets FEMA's standards for map accuracy. The NFHL data are from FEMA's Digital Flood Insurance Rate Map (DFIRM) databases. New data are added continually. The NFHL also contains changes to DFIRM data made by Letters of Map Revision (LOMRs). The service provides map images geo-referenced to the earth's surface using the North American Datum of 1983, Geodetic Reference System 80 coordinate system. The service also provides information that complements the National Flood Hazard Layer. In areas for which data are not available from the National Flood Hazard Layer, an older set of flood hazard data, named the "Q3" data, may be available. The service also provides information about the availability of flood data and maps, the national map panel scheme, river subbasins, and point locations for Letters of Map Amendment (LOMA) and Letters of Map Revision Based on Fill (LOMR-Fs). These complementary data are positioned less accurately than are the National Flood Hazard Layer data. The service organizes the data in layers. The layers display information at map scales appropriate for the data. Status information and river subbasins are displayed at map scales smaller than 1:300,000, regional overviews at map scales between 1:300,000 and 1:32,000, and detailed flood hazard maps at map scales of 1:32,000 and larger. The "Scalehint" item in the Capabilities file for the Web Map Service encodes the scale range for maps for a layer. Flood hazard areas identified on the Flood Insurance Rate Map are identified as a Special Flood Hazard Area (SFHA). SFHA are defined as the area that will be inundated by the flood event having a 1-percent chance of being equaled or exceeded in any given year. The 1-percent annual chance flood is also referred to as the base flood or 100-year flood. SFHAs are labeled as Zone A, Zone AO, Zone AH, Zones A1-A30, Zone AE, Zone A99, Zone AR, Zone AR/AE, Zone AR/AO, Zone AR/A1-A30, Zone AR/A, Zone V, Zone VE, and Zones V1-V30. Moderate flood hazard areas, labeled Zone B or Zone X (shaded) are also shown on the FIRM, and are the areas between the limits of the base flood and the 0.2-percent-annual-chance (or 500-year) flood. The areas of minimal flood hazard, which are the areas outside the SFHA and higher than the elevation of the 0.2-percent-annual-chance flood, are labeled Zone C or Zone X (unshaded). Flood Zone Definitions from the FEMA Flood Map Service Center. Data Download: https://www.floodmaps.fema.gov/NFHL/status.shtml

Flood Hazard Mapping is an important part of the U.S. National Flood Insurance Program. The Federal Emergency Management Agency publishes Flood Insurance Rate Maps that show areas where the annual likelihood of a flood is 1% or greater (Special Flood Hazard Areas). Because standard homeowners insurance does not cover flood damage the congress created the National Flood Insurance Program in 1968. In participating communities homeowners and renters are able to by federally-backed flood insurance. Dataset Summary This layer's data represents Federal Emergency Management Agency's (FEMA) Flood Insurance Rate Map (FIRM) data. This data is based upon the original vector data from FIRM. These data are important for floodplain management, mitigation, and insurance activities for the National Flood Insurance Program (NFIP). The National Flood Hazard Layer (NFHL) data present the flood risk information depicted on the FIRM in a digital format suitable for use in electronic mapping applications. The NFHL database is a subset of the information created for the Flood Insurance Studies (FIS) and serves as a means to archive a portion of the information collected during the FIS. The NFHL data incorporates Digital Flood Insurance Rate Map (DFIRM) databases published by Federal Emergency Management Agency (FEMA).  This layer initially shows the flood zones by FEMA Flood Zone Designations with this symbology: The layer covers the continental U.S. Link to source metadata (Metadata is specific to each locale.) What can you do with this layer? The vector features for this layer can be used for visualization and analysis in ArcGIS. The features in this layer are only visible at scales larger than 1:1,155,582. The features can also be downloaded for use with ArcGIS desktop by with the Extract Landscape Source Data tool. This layer is part of a larger collection of landscape layers that you can use to perform a wide variety of mapping and analysis tasks. This collection includes a raster layer that was derived from this data representing the locations of wetlands. Important Note: This layer is available for users with an ArcGIS Organizational subscription. To access this layer, you'll need to sign in with an account that is a member of an organizational subscription.  If you don't have an organizational subscription, you can create a new account and then sign up for a 30 day trial of ArcGIS Online. This service is currently in beta. For more information, see the Landscape Layers group on ArcGIS Online.

FEMA provides access to the National Flood Hazard Layer through a Web Map Service. The National Flood Hazard Layer is a computer database that contains FEMA's flood hazard map data. The data depict flood hazard information and supporting data used to develop the information. The primary hazard classifications are the 1 percent-annual-chance flood event, the 0.2 percent-annual-chance flood event, and areas of minimal flood hazard. Flood hazard and supporting data are developed using specifications for horizontal control consistent with 1:12,000-scale mapping. If you plan to display maps from the National Flood Hazard Layer with other map data for official purposes, ensure that the other information meets FEMA's standards for map accuracy. The NFHL data are from FEMA's Digital Flood Insurance Rate Map (DFIRM) databases. New data are added continually. The NFHL also contains changes to DFIRM data made by Letters of Map Revision (LOMRs). The service provides map images geo-referenced to the earth's surface using the North American Datum of 1983, Geodetic Reference System 80 coordinate system. The service also provides information that complements the National Flood Hazard Layer. In areas for which data are not available from the National Flood Hazard Layer, an older set of flood hazard data, named the "Q3" data, may be available. The service also provides information about the availability of flood data and maps, the national map panel scheme, river subbasins, and point locations for Letters of Map Amendment (LOMA) and Letters of Map Revision Based on Fill (LOMR-Fs). These complementary data are positioned less accurately than are the National Flood Hazard Layer data. The service organizes the data in layers. The layers display information at map scales appropriate for the data. Status information and river subbasins are displayed at map scales smaller than 1:300,000, regional overviews at map scales between 1:300,000 and 1:32,000, and detailed flood hazard maps at map scales of 1:32,000 and larger. The "Scalehint" item in the Capabilities file for the Web Map Service encodes the scale range for maps for a layer. Flood hazard areas identified on the Flood Insurance Rate Map are identified as a Special Flood Hazard Area (SFHA). SFHA are defined as the area that will be inundated by the flood event having a 1-percent chance of being equaled or exceeded in any given year. The 1-percent annual chance flood is also referred to as the base flood or 100-year flood. SFHAs are labeled as Zone A, Zone AO, Zone AH, Zones A1-A30, Zone AE, Zone A99, Zone AR, Zone AR/AE, Zone AR/AO, Zone AR/A1-A30, Zone AR/A, Zone V, Zone VE, and Zones V1-V30. Moderate flood hazard areas, labeled Zone B or Zone X (shaded) are also shown on the FIRM, and are the areas between the limits of the base flood and the 0.2-percent-annual-chance (or 500-year) flood. The areas of minimal flood hazard, which are the areas outside the SFHA and higher than the elevation of the 0.2-percent-annual-chance flood, are labeled Zone C or Zone X (unshaded). Flood Zone Definitions from the FEMA Flood Map Service Center. Data Download: https://www.floodmaps.fema.gov/NFHL/status.shtml

Important Note: This item is in mature support as of November 2018 and will be retired in December 2020.  A new version of this item is available for your use. Esri recommends updating your maps and apps to use the new version. Note: This data was acquired in 2013. The FEMA Mapping Products web page may have more recent data for your area of interest. Flood Hazard Mapping is an important part of the U.S. National Flood Insurance Program. The Federal Emergency Management Agency publishes Flood Insurance Rate Maps that show areas where the annual likelihood of a flood is 1% or greater (Special Flood Hazard Areas). Because standard homeowners insurance does not cover flood damage the congress created the National Flood Insurance Program in 1968. In participating communities homeowners and renters are able to by federally-backed flood insurance. Dataset Summary This layer's data represents Federal Emergency Management Agency's (FEMA) Flood Insurance Rate Map (FIRM) data. This data is based upon the original vector data from FIRM. These data are important for floodplain management, mitigation, and insurance activities for the National Flood Insurance Program (NFIP). The National Flood Hazard Layer (NFHL) data present the flood risk information depicted on the FIRM in a digital format suitable for use in electronic mapping applications. The NFHL database is a subset of the information created for the Flood Insurance Studies (FIS) and serves as a means to archive a portion of the information collected during the FIS. The NFHL data incorporates Digital Flood Insurance Rate Map (DFIRM) databases published by Federal Emergency Management Agency (FEMA).  This layer initially shows the flood zones by FEMA Flood Zone Designations with this symbology: The layer covers the continental U.S. What can you do with this layer? The vector features for this layer can be used for visualization and analysis in ArcGIS. The features in this layer are only visible at scales larger than 1:1,155,582.

The National Flood Hazard Layer (NFHL) data incorporates all Flood Insurance Rate Map (FIRM) databases published by the Federal Emergency Management Agency (FEMA), and any Letters of Map Revision (LOMRs) that have been issued against those databases since their publication date. It is updated on a monthly basis. The FIRM Database is the digital, geospatial version of the flood hazard information shown on the published paper FIRMs. The FIRM Database depicts flood risk information and supporting data used to develop the risk data. The primary risk classifications used are the 1-percent-annual-chance flood event, the 0.2-percent-annual-chance flood event, and areas of minimal flood risk. The FIRM Database is derived from Flood Insurance Studies (FISs), previously published FIRMs, flood hazard analyses performed in support of the FISs and FIRMs, and new mapping data, where available. The FISs and FIRMs are published by FEMA. The NFHL is available as State or US Territory data sets. Each State or Territory data set consists of all FIRM Databases and corresponding LOMRs available on the publication date of the data set. The specification for the horizontal control of FIRM Databases is consistent with those required for mapping at a scale of 1:12,000. This file is georeferenced to the Earth's surface using the Geographic Coordinate System (GCS) and North American Datum of 1983.