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<br />Peak discharges for Cherry Creek were previously determined as part <br />ofche ~.i114'~ 191fL J1DEcn~ Flood H~~~,..; AI'ea-DeLine&~ion -r-apo~t- for <br />Cherry Creek (Reference 10). Those discharges were computed using <br />the EPA Storm Water Management Model (Reference 37). The Cherry <br />Creek basin was assumed to be fully developed. <br /> <br />Peak discharges for Lakewood Gulch and Lakewood Gulch Overflow were <br />previously determined as part of the 19'6 UDFCD major drainageway <br />planning report (Reference 39). Those discharges were computed <br />using the Colorado Urban Hydrograph Procedure as outl ined in the <br />Urban Storm DrainaEe Criteria Manual (Reference 40). Split flows <br />were calculated along Lakewood Gulch in the reach between Decatur <br />Street and the South Platte River. The divergence of flows from <br />Lakewood Gulch at Decatur Street is referred to in thig study as <br />Lakewood Gulch Overflow. <br /> <br />Peak disCharges for Dry Gulch (Lakewood Gulch Tributary) were <br />previously determined as part of the 1977 UDFCD Flood Hazard Area <br />Delineation report (Reference 12). The Colorado Urban Hydrograph <br />Procedure (Reference 40) was used to compute the 10-, 50-, and <br />100-year events under fully developed basin conditions. The 500- <br />year flood peak was Obtained by extrapolation from the frequency- <br />discharge curve. ' <br /> <br />Peak discharges along Harvard Gulch, Harvard Gulch Overflow, Dry <br />Gulch (Harvard Gulch Tributary), and West Harvard Gulch were <br />determined as part of the 1979 UDFCD Flood Hazard Area Delineation <br />report (Reference 14). Those discharges were computed using the <br />Colorado Urban Hydrograph Procedure (Reference 40). <br /> <br />Split flows were calculated along Harvard Gulch between South <br />Downing Street and South Logan Street. Due to the limited capacity <br />of the box culvert between South Downing and South Ogden Streets to <br />carry the 100-year flood, flooding occurs overland to an old <br />channel, through a detention pond, and reJOlns Harvard Gulch. <br />These flows through Logan Park are referred to in this study as <br />-Harvard Gulch Overflow. <br /> <br />Dry Gulch (Harvard Gulch Tributary) consists of two 43- by 68-inch <br />reinforced-concrete pipe culverts along the entlre study reach. <br />These culverts carry only 250 cfs of the 1,330 cfs 100-year flood <br />event. The remaining floodwaters flow overland through a park area <br />and continue down Pearl Street to the confluence with Harvard <br />Gulch. <br /> <br />Peak discharges for Goldsmith Gulch and Southmoor Park Tributary <br />were determined as part of the 1976 UDFCD Flood Hazard Area <br />Delineation report (Reference 15). The 10- and 100-year discharges <br />were computed using the Colorado Urban Hydrograph Procedure <br />(Reference 40). The 50- and SOD-year discharges were obtained by <br />interpolation and extrapolation of the frequency-discharge curve. <br /> <br />Southmoor Park serves as <br />Southmoor Park Tributary. <br /> <br />a detention pond to reduce flows along <br />Reduced flows are released through an <br /> <br />17 <br />