The NRCS Floodway Determination (FLDWY) computer program is used to calculate a floodway at given cross sections along a stream. For this program, a floodway is defined as the minimum width at a cross section that is required to carry the selected flood with a specified increase in water surface elevation.
Before FLDWY can be used, the elevation of the selected flood at each cross section must be known. The input data for WSP2 can be used directly by FLDWY to make floodway calculations.
The Natural Resources Conservation Service used government funds to develop the Technical Release 64 (TR64) computer program. It may be downloaded for use and copying at no additional expense or license requirements.