Flood Insurance Rate Maps are produced by the U.S. Federal Emergency Management Administration. The FEMA Map Service Center provides access to current and historic maps as well as other information. Additionally FEMA provides access to map data for GIS applications, through the National Flood Hazard Layer.
IUB Libraries received the flood maps in print or microfiche for areas in Indiana through the Federal Depository Library Program until the late 1990's. The libraries also received CD-ROM products.
The most widely distributed flood map product is the Flood Insurance Rate Map (FIRM). Flood risk information presented on FIRMs is based on historic, meteorologic, hydrologic, and hydraulic data, as well as open-space conditions, flood control works, and development. To prepare FIRMs that illustrate the extent of flood hazard in a community, FEMA conducts engineering studies referred to as Flood Insurance Studies (FISs). Using information gathered in these studies, FEMA engineers and cartographers delineate Special Flood Hazard Areas (SFHAs) on FIRMs. SFHAs are areas subject to inundation by a flood that has a 1-percent or greater chance of being equaled or exceeded during any given year. This type of flood is referred to as a base flood. A base flood has a 26-percent chance of occurring during a 30-year period -- the length of many mortgages. The base flood is a regulatory standard used by Federal agencies, and most states, to administer floodplain management programs, and is also used by the National Flood Insurance Program as the basis for insurance requirements nationwide.
A variety of information can be found on FIRMs, including:
Flood Insurance Rate Maps have been issued by three different agencies over the last 30 years: Housing and Urban Development (HUD), Federal Emergency Management Agency (FEMA) and Homeland Security (HS).