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The National Flood Hazard Layer (NFHL) is a geospatial database that contains current effective flood hazard data for those communities where maps have been digitized. FEMA provides the flood hazard data to support the National Flood Insurance Program. You can use the information to better understand the level of FEMA-estimated flood risk and type of flooding in an area.
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.
This dataset comprises the Flood Hazard Zones layer of NFHL.
This is the depth for Zone AO areas
Study Identifier. For a single-jurisdiction Flood Risk Project, the value is composed of the two-digit State Federal Information Processing Standard (FIPS) code and the fourdigit FEMA Community Identification (CID) code (e.g., 480001). For a countywide Flood Risk Project, the value is composed of the two-digit State FIPS code, the three-digit county FIPS code, and the letter 'C' (e.g., 48107C).
Velocity measurement of the flood flow in the area. Normally this is applicable to alluvial fan areas (certain Zone AO areas). Field is populated only when a velocity is associated with the flood zone area.
Dual zones (AR/AE) are flood zones in a current restoration area (AR) but with additional risk of flooding from other water sources not addressed by the flood protection system being restored. This means that despite the completion of a levee repair project, the area will continue to be in a high risk flood zone due to a flooding source other than the AR Zone source.
Flood Zone. This is a flood zone designation. These values are used by FEMA to designate the SFHAs and for insurance rating purposes.
Study type. Describes the type of Flood Risk Project performed for flood hazard idenetification.
Version Identifier. Identifies the FIRM product version and relates the feature to standards according to how it was created.
Units of measuring system referred to in
FEMA-assigned unique identifier for this flood area
Units of measurement for the velocity of the 1-pct annual chance flood
Vertical Datum. Indicates the reference from which the flood elevations are measured. Only populated if
Summary flood risk level
Indicates whether area is within a FEMA-designated Special Flood Hazard Area (SFHA).
Flood Zone Subtype. Captures additional information about the flood zones not related to insurance rating purposes.
Static Base Flood Elevation. Populated for areas that have been determined to have a constant Base Flood Elevation (BFE) over a flood zone. This normally occurs in lakes or coastal zones.
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GET when your query carrries the request parameter appended in URL and
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