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• the rail bridge, as shown on Drawing 1. Surveyed cross sections were located at intervals ranging from <br />about 100 feet to 450 feet along the center line of the channel. Within the meander bend segment, cross <br />sections w-ere spaced at an interval of about I25 feet. <br />The deepest point along the channel at two cross sections (Section 6 and Section 7) could not be <br />measured at the time of the survey because the Flow in these segments was too swift and deep. The <br />deepest point at these two sections was determined by extrapolating from downstream segments as <br />shown in Figure 2-2. The water surface elevations at each cross section were also determined as part <br />of the channel survey. The corresponding water surface profile for April 16, 1999 is also shown on <br />Figure 2-2. <br />A hydraulic analysis was performed at each cross section using the measured flow and slope of the <br />water surface April l6, 1999 and the cross section dimensions, including wetted perimeter and cross <br />sectional area. Since a flow of 174 cfs was measured on April 16, 1999 at USGS Station No. <br />09249750 located at the bridge immediately upstream of Section 1, the average flow velocity was <br />• determined at each section from the surveyed cross sections and water surface elevations at each <br />section that were surveyed on April 16, 1999. The cross sections, the measured water surface <br />elevation, and the estimated velocity at each section for the measured flow of 174 cfs aze included in <br />Appendix A. An energy level at each section was determined from the measured water surface <br />elevations and corresponding velocity estimates. A plot of the energy profile in Figure 2-2 shows only <br />very slight deviation from the corresponding water surface profile, indicating that velocity heads were <br />minimal compared to the elevation heads, <br />• <br />AHA Filenarnc EmpveDes~~ doc 6 07/?0/B9 <br />