The floodplain districts established are defined by the base flood elevations and one-hundred-year floodplains as delineated in the Flood Insurance Study. The basis for the Flood Insurance Study is a scientific and engineering report entitled, "The Flood Insurance Study for Columbia Falls, Montana" dated October 15, 1985, with accompanying Flood Insurance Rate Maps and flood boundary/floodway maps. The official floodplain maps and study are on file in the office of the floodplain administrator. (Ord. 576 § 4(B), 1994)