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<br />Table 2. Summary of Cross Section. Locations and Elevations <br /> <br />Cross Section <br /> <br />Cross Section Location <br /> <br />Base Flood Water <br />Surface Elevation <br />(Regulatory) <br /> <br />Tri-Area <br /> <br />. 1 <br />DraJ..nageway <br />A <br />B <br />C <br />D <br />E <br />F <br /> <br />11490 <br />11700 <br />12090 <br />12540 <br />13210 <br />13970 <br /> <br />5011.7 <br />5011.7 <br />5014.1 <br />5020.6 <br />5025.4 <br />5031.5 <br /> <br />Unnamed Tributary t02 <br />Tri-Area Drainageway <br />A <br />B <br />C <br /> <br />280 <br />885 <br />1180 <br /> <br />5011.7 <br />5018.4 <br />5022.3 <br /> <br />1 <br />Feet Above Corporate Limits <br />2 <br />Feet Above Confluence With Tri-Area Drainageway <br /> <br />Locations of selected cross sections used in the hydraulic analyses <br />are shown on the Flood Profiles (Exhibit 1). <br /> <br />The water-surface profiles for the 10-, 50-, 100-, and SOa-year <br />floods were computed using the u.s. Army Corps of Engineers' HEC-2 <br />computer model (Reference 8). Starting water-surface elevations <br />were obtained from weir calculations at State Highway 52. <br /> <br />Flood profiles were drawn showing computed water-surface elevations <br />to an accuracy of 0.5 fort for floods of the selected recurrence <br />intervals (Exhibit 1). <br /> <br />Roughness coefficients (Manning llnll) were estimated by field inspec- <br />tion. The roughness coefficients for the drainageway and overbank <br />areas ranged between 0.045 and 0.060. In some overbank areas, "n" <br />values up to 0.090 were appropriate. <br /> <br />All elevations are referenced to the National Geodetic Vertical <br />Datum of 1929 (NGVD). Elevation reference marks used in the study <br />are shown on the maps. <br /> <br />4.0 FLOOD PLAIN MANAGEMENT APPLICATIONS <br /> <br />A prime purpose of the National Flood Insurance Program is to encourage <br />State and local governments to adopt sound flood plain management pro- <br />grams. Each Flood Insurance Study, therefore, includes a flood boundary <br /> <br />6 <br />