The land area covered by the floodwaters of the base flood (a flood having a 1% chance of occurring in any given year) is the Special Flood Hazard Area on National Flood Insurance Program (NFIP) maps. A high-risk flood zone is called a Special Flood Hazard Area (SFHA). It's also known as the 1% annual chance floodplain, commonly referred to as the "100-year floodplain." The 100-year flood is a standard used by the NFIP for floodplain management and to determine the need for flood insurance. Development may take place within the SFHA, provided that development complies with local floodplain management ordinances, which must meet the minimum Federal requirements. Flood insurance is required for insurable structures within high-risk areas to protect Federal financial investments and assistance used for acquisition and/or construction purposes within communities participating in the NFIP.