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that can be adopted directly or that can be used as a basis for additional floodway studies. The floodways presented in this study were computed on the basis of equal-conveyance reduction from each side of the flood plain. The results of these computations are tabulated at selected cross sections for each stream segment for which a floodway is computed (Table 3). Floodways were not computed for the Arkansas River and Timpas Creek. As shown on the Flood Boundary and Floodway Map (Exhibit 2) r the floodway boundaries were computed at cross sections. Between cross sections, the boundaries were interpolated. In cases where the floodway and IOO-year flood plain boundaries are either close together or collinear, only the floodway boundary has been shown. The area between the floodway and IOO-year flood plain boundaries is termed the floodway fringe. The floodway fringe encompasses the portion of the flood plain that could be completely obstructed without increasing the water-surface elevation of the IOO-year flood by more than I foot at any point. Typical relationships between the floodway and the floodway fringe and their signifi- cance to flood plain development are shown in Figure 2. I' 100.YEAR FLOOD PLAIN -I FLOOOWAY FRINGE FLOODWAY FLOODWAY FRINGE STREAM CHANNEL FLOOD ELEVATION WHEN CONFINED W!THIN FLOODWAY AREA OF FLOOD PLAIN THAT COULD BE USED FOR DEVELOPMENT BY RAISING GROUND "",1 FLOOD ELEVATION BEFQREENCROACHMENT ON FLOOD PLAIN LINE A8 IS THE FLOOD ELEVATION BEFORE ENCROACHMENT LINE CD IS THE FLOOD ELEVATION AFTER ENCROACHMENT. .SURCHARGE ISNOTTOEXCEEQ 1.0 FOOT (FEMA REQUIREMENT) OR LESSER AMOUNT IF SPECIFIED BY STATE. Figure 2. Floodway Schematic 10