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<br />based on channel and flood plain conditions as represented by <br />survey data gathered in Apri I 1975 and as supplemented by later <br />field Investigations. <br /> <br />. <br /> <br />The profiles on plates 9 through 23 show the water sur- <br />face elevations and water depth of the In-year, 50-year, 100-year, <br />and 500-year floods relative to the streambed. In this particular <br />case and throughout this study, the streambed is actually the chan- <br />nel low flow water surface elevation since the surveys were con- <br />ducted by aerial photogrammetric methods. The water surface ele- <br />vations of the 100-year and 500-year floods were used to determine <br />flood limits on the cross sections and topographic 1.laps. The <br />results are shown on the Flooded Areas, plates 3 through 8. An <br />index to the Flooded Areas plates Is on plate 2. Representative <br />cross sections are Illustrated on plates 24-28. The cross sections <br />show ground elevations across the valley on both sides of the <br />channel and the depths of overbank flooding. Reference points, <br />coinciding with the locations of the cross sections and pertinent <br />planimetric features are shown on the Flooded Areas and profile <br />for correlation between the drawings. Tables 7 and 8 provide data <br />at reference point locations, including distance along the main <br />channel centerline, elevations of the streambed, and elevations <br />of the 10-year, 50-year, IOO-year, and 500-year floods. <br /> <br />., <br /> <br />The Flooded Areas show the area that would be flooded <br />by the IOO-year and 500-year floods. The flood limits were <br />located at each cross section and the Intervening flood outlines <br />were drawn based upon detailed topographic mapping, engineering <br />Judgment, and field observations. It Is, however, possible that <br />more or less flooding should be shown on the Flooded Areas. For <br />a specific situation, where more detailed accuracy of flooded <br />area Is required, the flood limits can be more accurately <br /> <br />". <br /> <br />25 <br />