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<br />TABLE 1 - SUMMARY OF DISCHARGES <br /> <br />FLOODING SOURCES <br />AND LOCATION <br /> <br />DRAINAGE AREA <br />(SQ MILES) <br /> <br />10-YR <br /> <br />PEAK DISCHARGE (CFS) <br />50-YR 100-YR 500-YR <br /> <br />White River: <br /> <br />Downstream of con- <br />fluence with Coal <br />Mine Draw 3,300 <br /> <br />7,500 <br /> <br />13,500 <br /> <br />20,000 <br /> <br />35,000 <br /> <br />Upstream of confluence <br />with Douglas Creek, <br />above Rangely 2,880 <br /> <br />7,000 <br /> <br />13,000 <br /> <br />l8,500 <br /> <br />33,000 <br /> <br />About 3,100 feet down- <br />stream of State <br />Highway l3/789 872 <br /> <br />4,600 <br /> <br />5,900 <br /> <br />6,500 <br /> <br />7,700 <br /> <br />Coal Mine Draw: <br /> <br />At Mouth 2.9 <br />Above County Highway 2 2.1 <br /> <br />CoLlege Canyon Draw: <br />At Mouth <br />Above South White <br />Avenue <br /> <br />1.8 <br /> <br /> 290 690 830 1,200 <br /> 220 520 630 920 <br /> 1851 2101 2301 240l <br /> 200 460 560 l,080 <br />to overflow losses which occur at South White <br />Rangely. <br /> <br />1.5 <br /> <br />1 <br /> <br />Reduction in discharge is due <br />Avenue and Prospect Street in <br /> <br />3.2 Hydraulic Analyses <br /> <br />Analyses of the <br />riverine sources <br />the elevations of <br /> <br />hydraulic characteristics of flooding from <br />studied were carried out to provide estimates <br />floods of the selected recurrence intervals. <br /> <br />the <br />of <br /> <br />The water-surface elevations for the streams studied were computed <br />through use of the U.S. Army Corps of Engineers HEC-2 step-backwater <br />computer program (Reference 8). Cross sect ions for the backwater <br />analysis of the White River near Meeker were field surveyed at close <br />intervals above and below bridges and culverts in order to compute <br />the significant backwater effects of these structures. Additional <br />digitized cross sections were secured when the topographic maps were <br />compiled. <br /> <br />Cross sections for the backwater analysis on the White River near <br />Rangely, Coal Mine Draw, and College Canyon Draw were digitized from <br />1982 aerial photography (Reference 9). Since the cross sections for <br /> <br />8 <br />