FEMA produces Flood Insurance Rate Maps, commonly known as FIRMS, to support the National Flood Insurance Program. The FIRMs depict Special Flood Hazard Areas, the areas subject to inundation from the 1% annual chance flood (also known as the Base Flood or the 100-Year Flood). The SFHA determines where flood insurance is required as a condition of a federally insured loan through the NFIP mandatory purchase requirement. This requirement is intended to shift flood damage and recovery costs away from the general taxpayer and on to those who live in floodplains. The risk zones and flood elevations shown on the FIRMs within the SFHA are used to determine flood insurance rates. The SFHA also determines where NFIP floodplain management requirements must be enforced by communities that participate in the program. These include land use and building code standards. In addition to the NFIP, the FIRMs have also taken on additional uses. They are used within FEMAs Individual and Public disaster assistance programs, FEMAs Mitigation Grant Programs, emergency management, and in Massachusetts they identify areas were certain State Building Code and Wetlands Protection Act regulations must be enforced.

Current effective FIRMs can often be viewed at local community offices. They are also available to view and purchase online at FEMAs Map Service Center website. These maps can be amended or revised to reflect existing topography or changes in flood characteristics. The Letter of Map Amendment (LOMA) process is often used to challenge a lender's determination that a building is in the floodplain.

FEMA is currently involved in an effort to "modernize" and update their FIRM inventory. FIRMs need to be updated for a number of reasons, including outdated base maps, development in watersheds, advancements in flood modeling, etc. Modernized FIRMs include an updated orthophoto base map. These FIRMs will be known as Digital FIRMs because they will be produced as a digital GIS based product. The FHMP has partnered with FEMA to assist in the management and coordination of flood map modernization in Massachusetts.

Fact Sheet - FEMA Coastal Flood Mapping Methodology  pdf format of Fact Sheet - FEMA Coastal Flood Mapping Methodology

FEMA Map Service Center www.msc.fema.gov No registration required to view maps.

FEMA Multi-Year Flood Hazard Identification Plan (MHIP): http://www.fema.gov/media-library/assets/documents/6907

FEMA Flood Hazard Mapping Page https://www.fema.gov/national-flood-insurance-program-flood-hazard-mapping

LOMA/LOMR Information: https://www.fema.gov/floodplain-management/letter-map-amendment-loma

Cooperating Technical Partners: https://www.fema.gov/cooperating-technical-partners-program

FEMA Flood Hazard Mapping Tutorials: https://www.fema.gov/online-tutorials