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.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™.

According to FEMA the definition of a flood zone is a "geographic areas that FEMA has defined according to varying levels of flood risk and type of flooding. These zones are depicted on the published Flood Insurance Rate Map (FIRM) or Flood Hazard Boundary Map (FHBM)."

The National Flood Hazard Layer (NFHL) data incorporates all Digital Flood Insurance Rate Map(DFIRM) databases published by FEMA, and any Letters Of Map Revision (LOMRs) that have been issued against those databases since their publication date. The DFIRM Database is the digital, geospatial version of the flood hazard information shown on the published paper Flood Insurance Rate Maps(FIRMs). 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 NFHL data are derived from Flood Insurance Studies (FISs), previously published Flood Insurance Rate Maps (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 the Federal Emergency Management Agency (FEMA). The specifications for the horizontal control of DFIRM data are consistent with those required for mapping at a scale of 1:12,000. The NFHL data contain layers in the Standard DFIRM datasets except for S_Label_Pt and S_Label_Ld. The NFHL is available as State or US Territory data sets. Each State or Territory data set consists of all DFIRMs and corresponding LOMRs available on the publication date of the data set.

This dataset comes from the FEMA S_Fld_Haz_Ar table. The S_Fld_Haz_Ar table contains information about the flood hazards within the flood risk project area. A spatial file with location information also corresponds with this data table. These zones are used by FEMA to designate the SFHA and for insurance rating purposes. These data are the regulatory flood zones designated by FEMA. A spatial file with location information also corresponds with this data table.This information is needed for the following tables in the FIS report: Flooding Sources Included in this FIS report, and Summary of Hydrologic and Hydraulic Analyses.The spatial elements representing the flood zones are polygons. The entire area of the jurisdiction(s) mapped by the FIRM should have a corresponding flood zone polygon. There is one polygon for each contiguous flood zone designated.FEMA Regulatory Floodway are flood zone polygons marked as a regulatory floodway.FEMA 100 year are flood zone polygons where there is a 1% Annual Chance, also known as the 100 year.FEMA 500 year are flood zone polygons where there is a 0.2% Annual Chance, also known as the 500 year.This map is not intended for insurance rating purposes and is for information only. This map is a representation and approximation of the relative location of geographic information, land marks and physical addresses. The map may not be 100% accurate in locating your address. The floodplains shown on this mapping tool are those delineated on the Federal Emergency Management Agency’s (FEMA) Digital Flood Insurance Rate Map (DFIRM or floodplain map) for Montgomery County. This map is not an official FEMA Digital Flood Insurance Rate Map. The effective DFIRMs are produced, maintained, and published by FEMA and not by Montgomery County. Official determinations are provided by FEMA.

The FEMA Flood Hazard Layer represents the location and attributes of flood insurance risk zones from the 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 floodway, 100-year floodplain/SFHA (Special Flood Hazard Area), and the 500-year floodplain are all derived from this dataset.--Additional Information: Category: Hazard Purpose: The FIRM is the basis for floodplain management, mitigation, and insurance activities for the National Flood Insurance Program (NFIP). Insurance applications include enforcement of the mandatory purchase requirement of the Flood Disaster Protection Act, which "... requires the purchase of flood insurance by property owners who are being assisted by Federal programs or by Federally supervised, regulated or insured agencies or institutions in the acquisition or improvement of land facilities located or to be located in identified areas having special flood hazards, " Section 2 (b) (4) of the Flood Disaster Protection Act of 1973. In addition to the identification of Special Flood Hazard Areas (SFHAs), the risk zones shown on the FIRMs are the basis for the establishment of premium rates for flood coverage offered through the NFIP. The FIRM Database presents the flood risk information depicted on the FIRM in a digital format suitable for use in electronic mapping applications. The FIRM Database serves to archive the information collected during the Flood Risk Project. Update Frequency: As needed-- Metadata Link: https://www.portlandmaps.com/metadata/index.cfm?&action=DisplayLayer&LayerID=54347

A one-hundred-year flood is a flood event that has a 1% probability of occurring in any given year. The 100-year flood is also referred to as the 1% flood, since its annual exceedance probability is 1%,[1] or as having a return period of 100-years. The 100-year flood is generally expressed as a flowrate. Based on the expected 100-year flood flow rate in a given creek, river or surface water system, the flood water level can be mapped as an area of inundation. The resulting floodplain map is referred to as the 100-year floodplain, which may figure very importantly in building permits, environmental regulations, and flood insurance. 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.

Flood hazard areas for the Flood Insurance Rate Map (FIRM) published by the Federal Emergency Management Agency (FEMA) within Stark County, Ohio. These flood hazard areas are part of the National Flood Hazard Layer (NFHL). Flood hazard areas in this layer were merged into single records for each class to improve web map performance and symbolization. Flood hazard areas are sometimes referred to as flood hazard zones or flood plains. They depict the floodway (areas that are frequently flood), as well as the 100 and 500-year flood plains. The FIRM is the basis for floodplain management, mitigation, and insurance activities for the National Flood Insurance Program (NFIP). Insurance applications include enforcement of the mandatory purchase requirement of the Flood Disaster Protection Act, which requires the purchase of flood insurance by the owners of properties within areas identified as having flood hazards. This layer was downloaded from https://msc.fema.gov/portal/advanceSearch in September, 2021. It was last updated and published on September14, 2018.

This is a MD iMAP hosted service. Find more information on http://imap.maryland.gov. The DFIRM Database presents the flood risk information depicted on a given Flood Insurance Rate Map (FIRM) in a digital format suitable for use in electronic mapping applications. The DFIRM database is a subset of the Digital Flood Insurance Study (FIS) database that serves to archive the information collected during the FIS. This map service is a composite of Effective and Preliminary floodplain data. Q3 data is used where neither Effective or Preliminary data is available for a given community. 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 DFIRM Database is derived from Flood Insurance Studies (FISs) - previously published Flood Insurance Rate Maps (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 the Federal Emergency Management Agency (FEMA). The specifications for the horizontal control of DFIRM data files are consistent with those required for mapping at a scale of 1:12 - 000. Last Updated: 03/2016 Map Service Link: https://mdgeodata.md.gov/imap/rest/services/Hydrology/MD_Floodplain/FeatureServer ADDITIONAL LICENSE TERMS: The Spatial Data and the information therein (collectively "the Data") is provided "as is" without warranty of any kind either expressed implied or statutory. The user assumes the entire risk as to quality and performance of the Data. No guarantee of accuracy is granted nor is any responsibility for reliance thereon assumed. In no event shall the State of Maryland be liable for direct indirect incidental consequential or special damages of any kind. The State of Maryland does not accept liability for any damages or misrepresentation caused by inaccuracies in the Data or as a result to changes to the Data nor is there responsibility assumed to maintain the Data in any manner or form. The Data can be freely distributed as long as the metadata entry is not modified or deleted. Any data derived from the Data must acknowledge the State of Maryland in the metadata.

The entire Vermont extent of the National Flood Hazard Layer (NFHL) as acquired 12/15/15 from the FEMA Map Service Center msc.fema.gov upon publication 12/2/2015 and converted to VSP.The FEMA DFIRM NFHL database compiles all available officially-digitized Digital Flood Insurance Rate Maps. This extract from the FEMA Map Service Center includes all of such data in Vermont including counties and a few municipalities. This data includes the most recent map update for Bennington County effective 12/2/2015.DFIRM - Letter of Map Revision (LOMR) DFIRM X-Sections DFIRM Floodways Special Flood Hazard Areas (All Available)

This map shows the FEMA California flood zones. More information at FEMA (http://www.fema.gov/plan/prevent/fhm/dfm_dfhm.shtm#3).

© FEMA (http://www.fema.gov/index.shtm)

July 1997 (Download updated on 7/24/25)

This map includes the FEMA flood zone area typically included in the DFIRM panels. This is data provided by FEMA for the Santa Clara county area and made available from the City of Mountain View

Federal Emergency Management Agency Floodplain for Deschutes County, Oregon. Updated by FEMA nationwide in 2007, the FIRM is the basis for floodplain management, mitigation, and insurance activities for the National Flood Insurance Program (NFIP). Insurance applications include enforcement of the mandatory purchase requirement of the Flood Disaster Protection Act, which "requires the purchase of flood insurance by property owners who are being assisted by Federal programs or by Federally supervised, regulated, or insured agencies or institutions in the acquisition or improvement of land facilities located or to be located in identified areas having special flood hazards" (Section 2 (b) (4) of the 1973 Flood Disaster Protection Act). In addition to the identification of Special Flood Hazard Areas (SFHAs), the risk zones shown on the FIRMs are the basis for the establishment of premium rates for flood insurance coverage offered through the NFIP. Q3 Flood Data files convey certain key features from the existing hard copy FIRM. Edge-matching errors, overlaps and deficiencies in coverage, and similar problems are not corrected during digitizing or post-processing. The Q3 Flood Data files are intended to provide users with automated flood risk data that may be used to locate SFHAs. More detailed information may be obtained from the paper FIRM.

Raster image service of FEMA floodplain depth grid found here: https://casdsis.dcr.virginia.gov/arcgis/rest/services/Floodplains

The Federal Emergency Management Agency (FEMA) has broadened its delivery of flood hazard data to include a number of flood risk products. These flood risk products depict and describe the variability of flood risk in the vicinity of the 1% annual chance floodplains designated on the Flood Insurance Rate Maps (FIRMs). Flood Depth Grids are delivered to local officials during the Flood Risk Review Meetings as a part of the Flood Risk Database, prior to the preparation of the preliminary FIRMs. Flood Depth Grids allow local community officials to use technological and software advances to view and analyze hazards in their community from a new perspective.

A) This data describes the Special Flood Hazard Areas (SFHA's) pursuant to the Federal Emergency Management Agency's (FEMA's) Flood Insurance Rate Map (FIRM) for the City and County of San Francisco. B) These map products were created by FEMA and you can find more information on their creation on the following page: https://www.fema.gov/flood-maps/products-tools/products C) These maps are updated periodically in light of new information if flooding conditions change for a jurisdiction. This occurs on an as needed basis and is coordinated through the D) In order to use this dataset it is important to know what each zone designation means. You can find these designations below -- Zone AE, AO, and VE (AREAS WITH HIGH FLOOD RISK (SPECIAL FLOOD HAZARD AREAS; REGULATIONS APPLY): Properties within SFHAs are subject to flooding during the 1-percent-chance flood, a flood with a 1 percent chance of occurrence in any given year (also referred to as the Base Flood or 100-year flood). Zone D (AREA OF UNDETERMINED FLOOD RISK): In San Francisco, Zone D is an area of possible, but undefined, flood risk for waterfront piers operated by the Port of San Francisco. Zone X Shaded or Unshaded (AREA OF LOW OR MINIMAL FLOOD RISK): "Shaded" Zone X represents areas of moderate or low flood risk – these areas are subject to inundation during a flood having a 0.2-percent-annual-chance of occurrence, or during the 1-percent-annual-chance flood with depth less than 1 foot. "Unshaded" Zone X represents areas of minimal flood risk or areas that FEMA did not study or map. E) For regulatory implications of map, see: https://onesanfrancisco.org/San-Francisco-Floodplain-Management-Program For more detailed information on specific properties impacted by FIRM Map, see: https://sfplanninggis.org/PIM/

This dataset contains data from the National Flood Hazard Layer, a GIS database of flood risks and regulatory flood determination data. 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 minimum horizontal positional accuracy for base map hydrographic and transportation features used with the NFHL is the NSSDA radial accuracy of 38 feet. USGS imagery and map services that meet this standard can be found by visiting the Knowledge Sharing Site (KSS) for Base Map Standards (420). Other base map standards can be found at http://pm.riskmapcds.com/kss/MapChanges/default.aspx. You will need a username and password to access this information. The NFHL data are from FEMA’s Flood Insurance Rate Map (FIRM) databases. New data are added continually. The NFHL also contains map changes to FIRM data made by Letters of Map Revision (LOMRs). The NFHL is stored in North American Datum of 1983, Geodetic Reference System 80 coordinate system, though many of the NFHL GIS web services support the Web Mercator Sphere projection commonly used in web mapping applications. This dataset displays FEMA's Flood Insurance Rate Map (FIRM) panels. The spatial entities representing FIRM panels are polygons. The polygon for the FIRM panel corresponds to the panel neatlines. Panel boundaries are generally derived from USGS DOQQ boundaries. As a result, the panels are generally rectangular. FIRM panels must not overlap or have gaps within a study. In situations where a portion of a panel lies outside the jurisdiction being mapped, the user must refer to the S_Pol_Ar table to determine the portion of the panel area where the FIRM Database shows the effective flood hazard data for the mapped jurisdiction. This information is needed for the FIRM Panel Index and the following tables in the FIS report: Listing of NFIP Jurisdictions, Levees, Incorporated Letters of Map Change, and Coastal Barrier Resources System Information.View Dataset on the Gateway

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.For more information, visit https://msc.fema.gov/portal/home.

FEMA flood hazard areas for Metro Nashville and Davidson County.Source Link: https://www.fema.gov/flood-mapsMetadata Document: FEMA Flood Hazard Areas Metadata.pdfContact Data Owner: opendata@nashville.gov

This layer offers the anticipated floodplain boundaries however, the data shown are in the process of being reviewed and adopted by FEMA and a given community. Changes to the Preliminary boundaries may occur before official map adoption. Use this layer with caution. The effective regulatory floodplain should be used for conducting all official floodplain determinations until such time the preliminary floodplain is reviewed and adopted by FEMA and a given community. It is reasonable to assume that preliminary floodplain boundaries are more accurate than the Q3, but the Q3 may better represent the current regulatory Flood Insurance Rate Map (FIRM) when verified by using the paper FIRM. Last Updated: 8/31/2017