To provide communities with the information they need to enact and enforce floodplain management ordinances or laws, FEMA conducts floodplain studies for communities throughout the United States and publishes the results in Flood Insurance Studies (FISs) and Flood Insurance Rate Maps (FIRMs) (Figure 2-14). Digital Flood Insurance Rate Maps (DFIRMs) are also available in many communities. The FIS and FIRM for your community provide information about the names and locations of flooding sources, sizes and frequencies of past floods, limits of the Special Flood Hazard Area (SFHA) and floodway, flood flow velocities, and elevations of the base flood in the SFHA. With this information, communities can manage floodplain development and FEMA can establish flood insurance rates.
The floodway is the portion of the SFHA that must be kept free of new development so that flood elevations will not increase. The floodway usually consists of the stream channel and land along either side. The flood hazard is usually greater in the floodway than in the surrounding areas of the SFHA, referred to as the “flood fringe.”
The NFIP regulations do not prohibit development in the SFHA. Instead, they require that residential buildings in the SFHA be elevated to or above the BFE. But floodplain development can reduce the amount of space available to convey floodwaters and increase flood elevations. So this development must be controlled. The floodway is the regulatory means of providing the required control.
FIRMs are available online at FEMA’s Map Service Center (MSC), msc.fema.gov…. The site allows you to search for your flood map in one of four ways, by:
Once you find your FIRM, you can create a printable FIRMette using the MSC Viewer. A FIRMette is a full-scale section of a FEMA FIRM that you create for yourself online. There is no cost for making a FIRMette. FIRMettes are used by many different parties such as community officials, mortgage lenders, real estate agents, design professionals, insurers, land developers, engineers, and surveyors.
The MSC Viewer allows you to zoom to the area you want to be included in your FIRMette and format your printable map. You can save your FIRMette either as an Adobe PDF or as a Tiff Image File. The Map Service Center offers a step-by-step tutorial on creating FIRMettes.
Other Federal agencies, such as the U.S. Army Corps of Engineers, U.S. Geological Survey (USGS), and Natural Resources Conservation Service (NRCS, formerly the U.S. Soil Conservation Service), also publish flood information, as do some State and local agencies. This information is often useful as a supplement to FISs and FIRMs but, because it is developed to meet other needs, it is not used for the NFIP unless it has been reviewed and approved by FEMA.
If you have questions about flood hazards in your community, including the limits of the regulatory floodplain, flood elevations, or sizes and frequencies of past floods, check with your local officials. Usually, they will have copies of the FIS and FIRM for your community. They can also help you determine whether your home is in the regulatory floodplain and advise you about flood protection methods, including those described in this guide. Local officials can also advise you about floodplain management requirements, building codes, and other requirements that may determine the types of changes you can make to your home.