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<br />DRAFT <br /> <br />TABLE 2.10 - CONT. ADOPTED PEAK FLOWS FOR THE BLUE RIVER <br />AND ITS MAJOR TRIBUTARIES <br /> <br />---------------------------------------------------------------- <br /> <br />LOCATION <br /> <br />DISCHARGE (cfs) <br />2-YR 5-YR 10-YR 25-YR <br /> <br />50-YR 100-YR <br /> <br />---------------------------------------------------------------- <br /> <br />French Creek 110 200 280 375 490 708 <br />(CH-7) <br />Illinois Gulch 45 90 130 190 240 330 <br />(CH-6) <br />Illinois Gulch 45 90 130 190 240 330 <br />(CH-7) <br />---------------------------------------------------------------- <br />* Based on SWMM results <br /> <br />LOCAL DRAINAGE ANALYSIS <br /> <br />Peak discharges for the local drainage system within the developed <br />areas of the MPA were analyzed using the personal computer version <br />of the Storm Water Management Model (SWMM) developed for the Denver <br />Urban Drainage and Flood Control District (1985) and referred to <br />as UDSWM2-PC. The general area for which this analysis was <br />performed is outlined on Plates 1 and 2. The detailed drainage <br />network is depicted on Plates 3 through 12. Flood hydrographs and <br />their associated peaks were developed for the 2-, 5-, 10~, 25-, 50- <br />and 100-year storms. Both existing conditions and future <br />conditions were analyzed. The latter was based on full development <br />assuming densities and land use patterns per the guidelines in the <br />Breckenridge Master Plan. <br /> <br />Description of Methodoloqy <br /> <br />UDSWM2 consists of the runoff block of the EPA's SWMM as modified <br />by the Missouri River Diversion of the U.S. Army Corps of <br />Engineers. The water quality portion of SWMM is not included in <br />UDSWM2. The UDSWM2 represents the basin by an aggregate of <br />idealized subcatchments, channels, gutters and pipes. The program <br />accepts rainfall hyetographs and makes a step by step accounting <br />of rainfall infiltration losses in pervious areas, surface <br />retention, overland flow and gutter flow, leading to the <br />calculation of hydrographs. <br /> <br />with the UDSWM2-PC, the drainage basin may be subdivided into a <br />maximum of 399 subcatchment areas. The resulting hydrographs from <br /> <br />19 <br />