Floodplains

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.

Data e Risorse

Campo Valore
accessLevel public
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identifier https://www.arcgis.com/home/item.html?id=2e00d68b88064a37aef7b50cf0255092&sublayer=9
issued 2021-03-08T18:43:57.000Z
landingPage https://opendata.dc.gov/datasets/DCGIS::floodplains
license https://creativecommons.org/licenses/by/4.0
metadata_type geospatial
modified 2025-04-11T00:00:00.000Z
old-spatial -77.1199,38.7916,-76.9090,38.9960
publisher Federal Emergency Management Agency
resource-type Dataset
source_datajson_identifier true
source_hash 93e70f1782a041714d610a0adb29e2d069da0cc31bc4a986ee36d585cf19f04a
source_schema_version 1.1
spatial {"type": "Polygon", "coordinates": [[[-77.1199, 38.7916], [-77.1199, 38.9960], [-76.9090, 38.9960], [-76.9090, 38.7916], [-77.1199, 38.7916]]]}
theme {geospatial}
Gruppi
  • AmeriGEOSS
  • National Provider
  • North America
Tag
  • AmeriGEO
  • AmeriGEOSS
  • CKAN
  • GEO
  • GEOSS
  • National
  • North America
  • United States
  • dc
  • dc-gis
  • district-of-columbia
  • environment
  • environmental
  • fema
  • firm
  • floodplain
  • insurance
  • washington-dc
  • water
isopen True
license_id cc-by
license_title Creative Commons Attribution
license_url http://www.opendefinition.org/licenses/cc-by
maintainer DCGISopendata
maintainer_email gisgroup@dc.gov
metadata_created 2025-09-23T16:42:02.172610
metadata_modified 2025-09-23T16:42:02.172616
notes <div style='text-align:Left;'><div><div><p><span>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. </span></p><p><span>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.</span></p><p><span>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. </span></p><p><span>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 </span><a href='https://msc.fema.gov/portal/home' style='text-decoration:underline;' rel='nofollow ugc'><span>https://msc.fema.gov/portal/home</span></a><span>.</span></p></div></div></div>
num_resources 7
num_tags 19
title Floodplains