Agency implements new policy mandating digital data use and releases new digital tools.

This is a typical recent Flood Insurance Rate Map published by FEMA.  As is the case with many of FEMA's new maps, a digital orthophoto is included on the FEMA published version.  The blue area represents the high flood hazard.

For the past five years, Federal Emergency Management Agency (FEMA) has been updating the existing flood maps used for the National Flood Insurance Program (NFIP) and converting them from paper maps to digital geospatial data. These maps are used millions of times each year to assess the flood risk of homes and businesses across the country. A major benefit expected from this Flood Map Modernization Program, or Map Mod, is the ability to use new state-of-the-art digital maps in place of the paper flood maps.

Over the past several months, much progress has been made toward that goal. FEMA has issued a Use of Digital Flood Hazard Data policy, released a new National Flood Hazard Layer product (NFHL), begun consistently delivering digital products concurrently with paper maps, produced a suite of tools for using digital flood data and published users guides for these new products.

This is a customized map made from FEMA DFIRM data with a digital orthophoto included in addition to the road centerline that was shown of the paper version.  The new policy allows products like this to be used for official purposes, even though they do not look like a traditional FEMA flood map.  The red area represents the high flood hazard.

From Possibility to Product

While production and adoption of the digital data under Map Mod will continue for another couple of years, the basic tools are now in place to realize the vision of using all digital products.

It is now possible for a user with an accurate GPS position to instantly look up the flood zone for that location using the online NFHL service, which is updated daily, or integrate FEMA-produced digital flood data with community-provided aerial photos.

Congress included a provision in the Bunning-Bereuter-Blumenauer Flood Insurance Reform Act of 2004 stating that both the digital flood hazard data and paper products produced from it are legal for the NFIP. FEMA’s Use of Digital Flood Hazard Data policy clarifies the implementation of this law and defines the official paper and digital products produced by the agency.

The policy allows users to combine their own base map with the FEMA flood data if it meets FEMA’s accuracy standards. For example, a community may use its digital flood data published by FEMA in 2006 with new aerial photos produced by the community in 2008 to create a custom view of the flood plain for official NFIP business. This allows users to benefit from more recent and accurate local base map data without waiting for FEMA approval.

The policy defines the horizontal location of the flood hazard directly through mapping coordinates rather than defining the location relative to the base map. This makes it possible to always get the same result with any paper or digital product even when FEMA’s flood hazard data is combined with a local base map.

Of course, no one has to give up paper maps just yet. Users may continue to use the paper maps just as they always have. On the other hand, users may now elect to switch to FEMA’s Digital Flood Insurance Rate Map (DFIRM) Database product as the official version of the FEMA designated flood plain. This applies to map use for mandatory insurance purchase decisions and insurance rating, and it applies to local zoning and permitting provided that state and local laws allow it.

In order to produce flood maps quickly at the beginning of the flood mapping program, basic Flood Hazard Boundary maps like this were produced.  They do not show many of the details displayed on a Flood Insurance Rate Map.

Digital Tool Box

Several new digital tools are now available through the FEMA Map Service Center.

FIRM Scans:For users who need basic access to flood hazard maps over a specific geographic area, like a town, county or state, FIRM Scan images provide a simple, convenient replacement for paper maps. FIRM Scan images are digital pictures of entire flood maps, which can be downloaded or delivered on DVD and viewed and printed from a computer. To print the entire map, a specialized large-format printer is needed, but FEMA provides FIRMette-Desktop software to print a portion of the map (a FIRMette) on any printer.

FIRMettes:Online FIRMettes are the simplest way to see a flood hazard map for a specific location. FIRMettes show a section of a larger FIRM Scan image along with the map scale, north arrow and map identification information needed for NFIP activities. Users can save FIRMettes on their computers and print them. The online FIRMette-Web tool provides users with the information they need immediately at no cost.

MapViewer-Web:For users who want to do more than the simple FIRMette product allows and are comfortable with other online mapping sites, the MapViewer-Web tool provides additional capabilities. The viewer allows users to select the flood hazard information to be displayed and create custom maps and reports.

DFIRM Data:Organizations with geographic information systems (GIS) capabilities may be interested in the Digital Flood Insurance Rate Map (DFIRM) data. This product is designed for use with specialized GIS software and provides a tool for mapping and analysis that is much more powerful than traditional map products.

DFIRM data are available for many of the highest flood risk areas. The data are available as community- or county-based DFIRM Databases, which can be downloaded or delivered on DVD. The data are also available in the NFHL, which is updated regularly to include the content of subsequent changes from Letters of Map Revision.

The online version of the NFHL available through MapViewer-Web or as a Web mapping service is updated daily. The statewide NFHL GIS data delivered on DVDs are updated monthly. FEMA also offers a MapViewer-Desktop tool for viewing DFIRM databases and NFHL datasets loaded on a computer.

Web Mapping Service:Some GIS users may wish to access the NFHL through a Web map service. The Web map service provides flood hazard information online, on demand, and can be used with most GIS software and Web-based mapping applications. The NFHL Web mapping service works with Google Earth. A setup file that loads the data automatically into Google Earth is available from the Map Service Center.

Mapping out the Future

While this is a significant milestone, there is still more to be done. FEMA will continue to explain the benefits and encourage the use of its new digital tools. The agency will assess the demand for paper map products, and strategies must be formulated to cost-effectively meet the remaining needs for paper. This ongoing work will require a full review and update of program forms, guidance and training materials and related information to reflect the new flood hazard data products.

FEMA will also continue to transform its flood hazard data production processes to focus on delivering digital flood hazard products cost-effectively and streamline legacy processes that are no longer suitable in a digital environment. These process improvements will allow the agency to deliver better products more cheaply and in ways that better meet the needs of NFIP stakeholders.

FEMA will also work to use the new power of its digital flood hazard products and tools to improve operations, coordination and integration within FEMA, first focusing on updating procedures within the Risk Analysis Division of the Mitigation Directorate and then working outward. This technology may allow FEMA to take a geographic approach to mitigation, more fully and effectively assess community risks, support better planning, evaluate the benefits of hazard mitigation projects, underwrite and service flood insurance and support the emergency management mission of FEMA and the Department of Homeland Security.

More information on FEMA’s new digital tools is available at the FEMA Map Service Center Web site,

For more information on the new products and services for FEMA's Flood Hazard Map Data, go

FEMA’s Use of Digital Flood Hazard Data policy is available

Additional documentation is available from the FEMA library. Go, and enter search keyword “NFHL.”