FLOODPLAIN- Any land area susceptible to inundation by floodwaters from any source.
100-YEAR FLOOD- The flood having a one percent chance of being equalled or exceeded in magnitude in any given year. Contrary to popular belief, it is not a flood occurring once every 100 years.
100-YEAR FLOODPLAIN- The area adjoining a river, stream, or watercourse covered by water in the event of a 100-year flood.
FLOODWAY- The channel of a river or watercourse and the adjacent areas that must be reserved in order to discharge the 100-year flood without cumulatively increasing the water surface elevation more than one foot.
FLOOD FRINGE- That portion of the floodplain outside the floodway that is inundated by flood waters in which encroachment is permissible.
ENCROACHMENT- Any man-made obstruction in the floodplain which displaces the natural passage of flood waters.
SURCHARGE- An increase in flood elevation due to destruction of the floodplain that reduces it's conveyance capacity.