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<br />The floodway in this study is presented to local agencies as minimum <br />standards that can be adopted directly or that can be used as a <br />basis for additional floodway results. <br /> <br />Floodway widths were computed at cross sections. Between cross <br />sections, the floodway boundaries were interpolated. The results of <br />the floodway computations were tabulated for selected cross sections <br />(Table 2). In cases where the floodway and 100-year floodplain <br />boundaries are either close together or collinear, only the floodway <br />boundary has been shown. <br /> <br />The area between the floodway and the 100-year flooplain boundaries <br />is termed the floodway fringe. The floodway fringe encompasses the <br />portion of the floodplain that could be completely obstructed <br />without increasing the water-surface elevation of the 100-year flood <br />by more than 1. 0 foot at any point. Typical relat ioships between <br />the floodway and the flodway fringe and their signicance to <br />floodplain development are shown in Figure 2. <br /> <br />I- <br /> <br />100.YEAR FLOODPLAIN <br /> <br />-I <br /> <br />. <br /> <br />FLOODWAY <br />FRINGE <br /> <br />- <br /> <br />FLOODWAY <br /> <br />FLOODWA Y <br />FRINGE <br /> <br />STREAM _ <br />CHANNEL <br /> <br />FLOOD ELEVATION WHEN <br />CONFINED WITHIN FLOODWAY <br /> <br /> <br />ENCROACHMENT <br /> <br />ENCROACHMENT <br /> <br />AREA OF FLOODPLAIN THAT COULD BE USED <br />FOR DEVELOPMENT BY RAISING GROUND <br /> <br /> <br />FLOOD ELEVATION BEFORE <br />ENCROACHMENT ON FLOODPLAIN <br /> <br />LINE AB IS THE FLOOD ELEVATION BEFORE ENCROACHMENT. <br />LINE CD IS THE FLOOD ELEVATION AFTER ENCROACHMENT. <br />'SURCHARGE IS NOT TO EXCEED 1.0 FOOT (FIA REQUIREMENT) OR LESSER AMOUNT IF SPECIFIED BY STATE. <br /> <br />Figure 2. Floodway Schematic <br /> <br />11 <br />