The area of a flat valley floor that a river, swollen by spring melt and spring rains in some parts of the country, and by hurricanes and tropical storms in others, will cover when it overflows its usual course or banks is its floodplain. It is an area in which you will probably not be able to buy flood insurance from a private company. Floodplain incursions are measured according to a river’s history—a variety of frequencies depending on the region’s hydrology and the upstream control by dams. The hundred-year floodplain is inundated once a century; the one-year floodplain, annually. The means of managing floodplain regions includes dikes, floodways, and zoning and building codes—these regulated by community or state law, unless they do not meet federal government, especially Federal Emergency Management Agency (FEMA), minimum standards; then federal law applies.

Larry Woiwode