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<br />. <br /> <br />. <br /> <br />. <br /> <br />. <br /> <br />elevations of the topographic maps is tabulated. <br />This tabulation is called the plotting table. <br />The location of all flood contours in the channel <br />are marked at the appropriate station along the <br />centerline on the base maps. <br />The flood contours are extended by drawing <br />"wiggly or reference lines" perpendicular to the <br />direction of flow until they intercept their <br />corresponding ground contours. jThe point at <br />which the flood contour intercepts the corres- <br />ponding ground contour is the edge of the flood- <br />plain, where water and ground meet. In general, <br />the flood contours should parallel the cross- <br />sections. If the cross-sections were incorrectly <br />located in the first place, however, the flood <br />contours may cross them. <br />Flooded area boundaries are drawn by connecting <br />the ends of each "wiqgly or reference line. n <br />The flood delineation should be checked for <br />reasonability and consistency with the cross- <br />section data (top width of the floodplain). <br /> <br /> <br />. <br /> <br />. <br /> <br />. <br /> <br />This is a simplified method which has many advan- <br />tages over the more common practice of drawing the <br />flood boundaries by connecting end points plotted <br />from top width at each cross-section. The most <br />important advantage is the degree of confidence <br />-28- <br /> <br />