Skip to Content

Home  » Tools & Links

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
Contents

Introduction

Google Earth example 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

"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_v3.0.kmz

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

"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 (LOMR–Fs). 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_v3.0.kmz

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.

Getting Started in Google Earth™

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).

Image of NFHL view in Google Earth

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
  • Floodways
  • 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

Frequently Asked Questions (FAQs)

  • What is the NFHL?

  • What NFHL Service is right for a user?

  • What does the "Big red X" on the map display imply?

  • Why is the "FEMA NFHL" folder or "fly to" entry field (area B in Figure 1) not visible?

  • How do I turn off the Quick Start Instructions?

  • How do I use other information to "fly to" a location?

  • What do I do if I double-clicked in the "Places" panel and unexpectedly caused Google Earth to " fly to" Pittsburgh (or Lewes, Delaware, Port Noches, Texas or the lower 48 States)?

  • Why is the "Eye alt" (eye altitude) readout (area D in Figure 1) not visible?

  • The map display has a confusing set of overlays that I do not remember turning on. How do I limit the overlays to those that I want to see?

  • Why might the flood map and Google Earth imagery not register?

  • Why is the KMZ responding slowly?

  • Should the KMZs be used for making flood determinations?

  • What are the steps to take if after opening either KMZ file a "Red X" appears?