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<br />COnmunlt1es in this aspect of floodplain management. Under this <br />concept, the area of the lOO-year floodplain is divided into a <br />floodway and a floodway fringe. The floodway is the channel of a <br />stream, plus any adjacent floodplain areas, that must be kept free <br />of encroachment S'O that: the lOO-year flood can be carried without <br />substantial increases in flood heights. Minimum Federal standards <br />limit such increases to 1.0 foot, provided that hazardous <br />velocities are not: produced. The floodways in this study are <br />presented to local agencies as minimum standards that can be <br />adopted dir&ctly or that can be used as a basis for additional <br />floodway studies. <br /> <br />A floodway was not computed for Cherry Creek because the <br />determination of a floodway was not within the scope of this study. <br /> <br />Karvard Gulch, downstream of South Logan Street, and Dakota Avenue <br />Tributary are shallow flooding areas for which the floodway concept <br />is not applicable. <br /> <br />No floodway has been presented for Karvard Gulch between South <br />Ogden and South Logan Streets and for Karvard Gulch Overflow due to <br />the fully developed nature of this area. <br /> <br />No floodways were delineated along the South Platte River primarily <br />due to split-flow conditions. <br /> <br />The floodways presented in this study were computed on the basis of <br />equal conveyance reduction from each side of the floodplain. The <br />results of these computations are tabulated at' selected cross <br />sections for each stream segment for which a floodway is computed <br />(Table 3). <br /> <br />As shown on the Flood Insurance Rate Map, the floodway boundaries <br />were computed at cross sections. Between cross sections, the <br />boundaries were interpolated. In cases where the floodway and 100- <br />year floodplain boundaries are either close together or collinear, <br />only the floodway boundary has been shown. <br /> <br />The area between the floodway and 100-year floodplain boundaries is <br />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 lOa-year <br />flood by more than 1.0 foot at any point. Typical relationships <br />between the floodway and the floodway fringe and their significance <br />to floodplain development are shown in Figure 2. <br /> <br />18 <br />