We are providing FEMA National Flood Map Web Mapping Service for the United States. This service is in compliance with OGC's Web Map Service (WMS) Interface Specification 1.1.1. You can download the WMS Capabilities file at the following URL:
https://hazards.fema.gov/wmsconnector/wmsconnector/Servlet/flood?REQUEST=GetCapabilities&SERVICE=WMS
Save file to your desktop as flood.xml. You may then view the document.
The WMS responds to GetMap requests at the following URL:
https://hazards.fema.gov/wmsconnector/wmsconnector/Servlet/flood?
Access Flood Map Data Symbology
The Web Map Service (WMS) Interface Specification is published by the Open GIS Consortium (OGC). WMS provides a standard for Internet-based retrieval of geospatial maps, and is a core component of the OGC Web Services suite.
This WMS service provides public access to Nationwide FEMA DFIRM and Q3 Flood Maps. Digital Flood Insurance Rate Map (DFIRM) layers are still in the development and production phase, and the national coverage of DFIRM datasets will continue increasing. As an alternative, Q3 datasets are used for communities without DFIRM datasets. Spatial features in Q3 flood layer overlapped with DFIRM flood layers are removed in this service.
The DFIRM 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 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 file is geo-referenced to earth’s surface using the North American Datum of 1983, Geodetic Reference System 80 coordinate system. The specifications for the horizontal control of DFIRM data files are consistent with those required for mapping at a scale of 1:12,000. The service contains associated layers in the Standard DFIRM datasets.
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 facilitie” 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 DFIRM Database presents the flood risk information depicted on the FIRM in a digital format suitable for use in electronic mapping applications. The DFIRM database is a subset of the Digital FIS database that serves to archive the information collected during the FIS.
For more information related to DFIRM datasets, see the following online FEMA documents:
The Q3 Flood Data are derived from the Flood Insurance Rate Maps (FIRMs) published by the Federal Emergency Management Agency (FEMA). The data is geo-referenced to the earth surface using the EPSG:4326 (latitude/longitude coordinate system). Specifications for the horizontal control of Q3 flood data are consistent with those required for mapping at a scale of 1:24000. These data are for advisory purposes only.
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, the risk zones shown on the FIRMs are the basis for the establishment of premium rates for flood coverage offered through the NFIP. Q3 Flood Data files are intended to convey certain key features from the existing hard copy FIRM to provide users with automated flood risk data. Edge-matching errors, overlaps and deficiencies in coverage, and similar problems are not corrected during digitizing or post-processing. These data may be used to locate Special Flood Hazard Areas (SFHAs). More detailed information may be obtained from the paper FIRM.
Important Notice Regarding the Q3 Data:
The Q3 Flood Data is available for approximately 1,300 (out of over 3,100) counties across the United States. Approximately 75% of US households are in these counties.
The Q3 data displayed on this web site was developed by scanning the existing FIRM hardcopy and capturing a thematic overlay of flood risks. The Q3 data files contain only certain features from the FIRM hardcopy in effect at the time of scanning (1996-2000) and do not replace the existing FIRM hardcopy maps. Updates to the effective maps may have been made since the Q3 data was developed, and it is up to the user to ensure that the Q3 data has the same date as the most current effective FIRM.
The maps displayed on this site should be considered an advisory tool for general hazard awareness, education, and floodplain management. The flood hazard maps displayed on this site are not the legal document to be used when making a single site flood hazard determination. For more information on these maps, please refer to FEMA’s Frequently Asked Questions page.
It is anticipated that the Q3 data will be replaced by Standard DFIRM databases or updated as FEMA’s Flood Map Modernization (Map Mod) is implemented over the next few years. A Standard DFIRM Database includes GIS files that were used to create a current DFIRM paper map. Unlike the Q3 data, the DFIRM databases will be of the same spatial precision and accuracy of the paper maps. For more information about FEMA’s Map Mod, see: https://www.fema.gov/plan/prevent/fhm/mm_main.shtm.
For more information and recommendations about the limitations of Q3 flood data, see the following online FEMA documents: