Any land area susceptible to being inundated by floodwater from any source, including rivers, streams, coastal waters, and areas with inadequate drainage. The regulatory floodplain is the land area covered by the floodwaters of the base flood (1% annual chance flood), also called the Special Flood Hazard Area. Floodplain management regulations restrict development in these areas to reduce flood damage and protect lives. Properties in the regulatory floodplain typically require flood insurance if they have federally backed mortgages. Floodplain boundaries are shown on FEMA Flood Insurance Rate Maps and are subject to change as conditions evolve.