HIFLD OPEN National Flood Hazard Layer (NFHL) Lines

Principal Investigator(s):  View help for Principal Investigator(s) Federal Emergency Management Agency; United States Department of Homeland Security

Version:  View help for Version V1

Name File Type Size Last Modified
metadata.xml application/xml 7.7 KB 12/02/2025 06:10:AM
national-flood-hazard-layer-line-nfhl-1-geopackage.zip application/zip 21.6 GB 08/25/2025 07:45:PM

Project Citation: 

Federal Emergency Management Agency, and United States Department of Homeland Security. HIFLD OPEN National Flood Hazard Layer (NFHL) Lines. Ann Arbor, MI: Inter-university Consortium for Political and Social Research [distributor], 2025-12-02. https://doi.org/10.3886/E240863V1

Project Description

Project Title:  View help for Project Title HIFLD OPEN National Flood Hazard Layer (NFHL) Lines
Summary:  View help for Summary
The National Flood Hazard Layer (NFHL) is a compilation of GIS data that comprises a nationwide digital Flood Insurance Rate Map. The GIS data and services are designed to provide the user with the ability to determine the flood zone, base flood elevation, and floodway status for a particular location. It also has information about the NFIP communities, map panels, cross sections, hydraulic structures, Coastal Barrier Resource System, and base maps such as road, stream, and public land survey data. Through flood studies, FEMA produces Flood Insurance Study Reports, FIRM Panels, and FIRM Databases. FIRM Databases that become effective are incorporated into the NFHL. Updates to the NFHL are issued through Letters of Map Revision (LOMRs) and Letters of Map Amendment (LOMAs). Continuously updated, the NFHL serves as a Digital Flood Insurance Rate Map representing the current effective flood data for those communities where maps have been digitized. NFHL data can be viewed with widely available GIS software, including freely available programs that work with GIS shapefiles. For more information on the NFHL, see the online resources referenced herein. Using base maps: The minimum horizontal positional accuracy for base map hydrographic and transportation features used with the NFHL is the NSSDA radial accuracy of 38 feet. Letter of Map Amendment (LOMA) point locations are approximate. The location of the LOMA is referenced in the legal description of the letter itself. LOMA points can be viewed in the NFHL Interactive Map on the FEMA GeoPlatform.

This dataset consists of lines or boundaries of flood hazard areas.
Original Distribution URL:  View help for Original Distribution URL https://hifld-geoplatform.hub.arcgis.com/

Scope of Project

Subject Terms:  View help for Subject Terms HIFLD Open; GIS; floods; risk; water
Geographic Coverage:  View help for Geographic Coverage United States
Time Period(s):  View help for Time Period(s) 12/10/2020 – 10/31/2024
Data Type(s):  View help for Data Type(s) geographic information system (GIS) data
Collection Notes:  View help for Collection Notes Archived from the HIFLD Open GIS data repository, which was deactivated on August 26, 2025.


Related Publications

Download this project

Published Versions

V1 [2025-12-02]

Export Metadata

Dublin Core

DDI 2.5

Report a Problem

Found a serious problem with the data, such as disclosure risk or copyrighted content? Let us know.

This material is distributed exactly as received from the data depositor. ICPSR has not reviewed, checked, or processed this material. For additional information about the study, please contact the investigator(s) directly. If you have questions about the accessibility of materials distributed by ICPSR or require further assistance, please visit ICPSR's Accessibility Center.