Using the National Flood Hazard Layer Web Map Service (WMS) in Google Earth™
Now Available! National Flood Hazard Layer (NFHL) Geographic Information Systems (GIS) Data for Download.
The following changes have been made to the MSC Product Catalog and Map Search:
- NFHL Data are now searchable through Map Search
- NFHL databases are downloadable from MSC Product Catalog
- Effective FIRM Databases are no longer be available for purchase and users will instead be directed to download the effective NFHL data at no charge. Future Effective FIRM Databases are still available for purchase
Google Earth is a popular Internet application through which users can view maps. This web site provides zipped Keyhole Markup Language (.kmz) files through which users can view map overlays created from FEMA's National Flood Hazard Layer on Google Earth images.
You must already have the Google Earth application installed on your computer to use these files. The starting point for obtaining the software is http://earth.google.com. Information about the system requirements needed for your computer to run the software is available through http://earth.google.com/support. A user guide is available at http://earth.google.com/userguide.
FEMA offers two applications: "Stay Dry" and "FEMA NFHL." Stay Dry is more simple and focused. NFHL
is less limited but more complex to use. Each is described below, and each has its own .kmz file. For optimum
performance, please do not open both, and do not have more than one copy of each, in Google Earth at the same time.
To use the .kmz files, first save them to your computer. Do this by right-clicking on a hyperlinked file name below,
choosing "Save Target as" (Internet Explorer) or "Save Link As" (Firefox), changing the file name if you wish (be sure
that the file name has the extension .kmz), and clicking on save.
After saving the file, double-click on the file on your computer. This action should start Google Earth
and provide the opening view for the application.
If you plan to use mapped flood information displayed in Google Earth for official purposes, insure that
imagery and other map information displayed with the flood data meet FEMA's standards for map accuracy.
Some Geographic Information System (GIS) software can import GIS data encoded in the kmz format used for
these applications. This technique is unlikely to work with the kmz files provided below. If you are interested
in using the NFHL in GIS software, use the NFHL GIS data or NFHL Web Map Service (WMS) or Representative State Transfer
REST) Service. All product options and services are available through FEMA's Map Service Center (MSC) at http://msc.fema.gov.
FEMA anticipates future improvements to the .kmz files, so please revisit this page occasionally to obtain the latest version.
"Stay Dry" is a focused application that provides basic flood hazard map information from FEMA's National Flood Hazard Layer for an address. It allows you to view flood hazard zones and Flood Insurance Rate Map numbers and boundaries.
For best performance please delete or turn off previous versions of the "Stay Dry" or "FEMA NFHL" folders that you have loaded in Google Earth before using the new version of "Stay Dry."
Stay Dry Google Earth Application Instructions
Version 3.0 has simplified flood hazard symbols which match the latest in Flood Insurance Rate Map (FIRM)
specifications and aligns the zone definitions with the common Flood Smart definitions.
Please use version 3.0 instead of previous versions.
"FEMA NFHL" is a general application that provides for the display of flood hazard zones and labels,
floodways, Coastal Barrier Resources System and Otherwise Protected Area units, community boundaries and names,
base flood elevations, cross sections and coastal transects and their labels, hydraulic and flood control structures,
flood profile baselines, coastal transect baselines, limit of moderate wave action lines, river mile markers, and Flood
Insurance Rate Map and Letter of Map Revision boundaries and numbers. Additional reference layers include the status of NFHL data
availability, point locations for Letters of Map Amendment (LOMAs) and Letters of Map Revision Based on Fill (LOMRFs). You control
the information displayed by turning layers on and off. A basic knowledge of Google Earth and FEMA flood hazard information will help users of this application.
The name of each layer is hyperlinked to a description of the layer, the map symbols used for the layer, and links to other FEMA
web sites relevant to the layer. If a layer is turned on, clicking the text below the name of the layer (text that starts with "Draws at
zooms the Google Earth view to a sample display of the layer. Layers are organized for display at one or more of three "eye altitude" (map scale)
ranges in Google Earth: status maps at high altitudes, regional overviews of flood hazards at medium altitudes, and detailed flood hazard maps at
low altitudes. Click on the hyperlinked folder name of the application to see the altitudes at which data in the layers are displayed.
For best performance please delete or turn off previous versions of the "Stay Dry" or "FEMA NFHL" folders that you have loaded in
Google Earth before using the new version of "FEMA NFHL."
FEMA NFHL Google Earth Application Instructions
Version 3.0 includes a new NFHL data status layer, simplified flood hazard symbols
which match the latest in Flood Insurance Rate Map (FIRM) specifications and an updated
organization of features and layers to align with the latest FIRM Database schema.
Users of recent versions of the Google Earth viewer software should upgrade to version 3.0 to
avoid the problem in which the status map does not refresh.
You must have the Google Earth viewer software installed on your computer.You can obtain the software at http://earth.google.com/.
For best performance, please delete or turn off previous versions of the Stay Dry or FEMA NFHL folders that you have loaded in Google Earth.
Opening the Application
First session: Double-click on the FEMA NFHL
.kmz file that you downloaded to your computer.
Google Earth will open and display the FEMA
NFHL welcome button (see area a in Figure 1), a
map overlay that shows the status of data
coverage (see area b), and the "National Flood
Hazard Layer (FEMA)" folder under Temporary
Places in the "Places"panel (area c). Other
important areas are the navigation controls for
Google Earth (area d) and the eye altitude ("Eye alt") readout (area e).
Figure 1. Opening view for the FEMA NFHL utility.
Areas of interest include the (A) Quick Start Guide, (B) Fly to Search bar, (C) "National Flood Hazard Layer (FEMA)" folder,
(D) eye altitude readout, (E) map legend, and (F) navigation controls.
What data layers are available and at what eye altitudes do they display?
|For "high" eye altitudes (higher than 25 miles):
||For "medium" and "low" eye altitudes (from 25 miles to maximum zoom):
- Status of digital flood hazard data coverage
- Political Jurisdictions
- CBRS and OPA areas
- River Mile Markers
- Flood Hazard Zones and Labels
- Base Flood Elevations (BFEs)
- LOMR boundaries and case numbers
- LOMA and LOMR-F locations and case numbers
- Cross-Sections and Coastal Transects
- Levees and General Structures
- Profile and Coastal Transect Baselines
- LiMWA lines