A term used by the Federal Emergency Management Agency (FEMA) in the National Flood Insurance Program (NFIP) to refer to the land area covered by the floodwaters of the base or 100-year flood (an area of land that has an approximate 1 percent probability of a flood occurring on it in any given year). In these areas, the NFIP’s floodplain management regulations must be enforced, and the mandatory purchase of flood insurance applies. Structures located in SFHAs have a 26 percent chance of suffering flood damage over the normal 30-year life of a loan, according to FEMA. Structures that are not located in SFHAs are viewed as less subject to flooding. SFHAs are identified in flood insurance rate maps (FIRMs).