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<br />Red Canyon <br />Floodplain Information Report <br /> <br />Mesa County, Colorado <br /> <br />Red Canyon HEC-HMS SCS Hydrologic Parameters <br />Subbasin Lag Time Calculations <br /> <br />SCS <br />Lag* <br />(min) <br />34 <br />20 <br />20 <br />31 <br />23 <br />27 <br />22 <br />19 <br />26 <br />11 <br /> <br />SCS La!l Time <br /> <br />Tc <br />(min) <br />57 <br />34 <br />33 <br />51 <br />39 <br />45 <br />36 <br />32 <br />44 <br />19 <br /> <br />Tt3 <br />(min) <br />16 <br />2 <br />12 <br />~ <br />17 <br />16 <br />o <br />16 <br />1 <br />o <br /> <br />Tt2 <br />(min) <br />9 <br />12 <br />6 <br />.12. <br />2 <br />5 <br />25 <br />2 <br />28 <br />2 <br /> <br />Tt1 <br />(min) <br />32 <br />20 <br />14 <br />27 <br />20 <br />24 <br />11 <br />14 <br />15 <br />17 <br /> <br />Tt3 <br />(hr) <br />0.27 <br />0.04 <br />0.20 <br />0.14 <br />0.28 <br />0.27 <br />0.00 <br />0.26 <br />0.02 <br />0.00 <br /> <br />Channel Flow (Tt3) <br />Average ** <br />Slope Velocity <br />(flIft) (flIs) <br />0.103 11.00 <br />- - <br />0.274 5.00 <br />0.107 <br />0.176 <br />0.060 <br />0.096 <br /> <br />1100 <br />1300 <br />9.00 <br />11.00 <br /> <br />6.00 <br />1000 <br /> <br />0.023 <br />0.092 <br /> <br />Flow <br />Length <br />.J!!L <br />10650 <br />1895 <br />7925 <br />6515 <br />9075 <br />10795 <br />o <br />5630 <br />565 <br />o <br /> <br />Tt2 <br />(hr) <br />0.16 <br />0.19 <br />0.11 <br />0.26 <br />0.04 <br />0.08 <br />OA2 <br />0.04 <br />OA7 <br />0.03 <br /> <br />Shallow Concentrated Flow (Tt2) <br />Average <br />Velocity <br />(flIs) <br />3.78 <br />5.61 <br /> <br />5.23 <br />4.65 <br />10.79 <br />6.27 <br />2.89 <br />6.51 <br />3.10 <br />4.92 <br /> <br />Paved or <br />Unpaved <br />Unpaved <br />Unpaved <br />Unpaved <br />Unpaved <br />Unpaved <br />Unpaved <br />Unpaved <br />Unpaved <br />Unpaved <br />Un [laved <br /> <br />Slope <br />(flIfl) <br />0.055 <br />0.121 <br />0.105 <br />0.083 <br />OA47 <br />0.151 <br />0.032 <br />0.163 <br />0.037 <br />0.093 <br /> <br />Flow <br />Length <br />J!!L <br />2120 <br />3880 <br />2025 <br />4410 <br />1395 <br />1880 <br />4340 <br />830 <br />5290 <br />615 <br /> <br />Tt1 <br />(hr) <br />0.53 <br />0.33 <br />0.23 <br />OA5 <br />0.33 <br />DAD <br />0.18 <br />0.24 <br />0.24 <br />0.28 <br /> <br />Tt1) <br /> <br />n <br />Q13 <br />Q13 <br />Q13 <br />Q13 <br />Q13 <br />Q13 <br />Q13 <br />Q13 <br />Q13 <br />Q13 <br /> <br />Sheet Flow <br /> <br />Slope <br />(flIft) <br />0.030 <br />0.097 <br />0.233 <br />0.047 <br />0.097 <br />0.063 <br />OA47 <br />0.220 <br />0.217 <br />0.157 <br /> <br />Flow <br />Length <br />(ft) <br />300 <br />300 <br />300 <br />300 <br />300 <br />300 <br />300 <br />300 <br />300 <br />300 <br /> <br />.0 <br /> <br />Total Flow <br />Length (ft) <br />13070 <br />6075 <br />10250 <br />11225 <br />10770 <br />12975 <br />4640 <br />6760 <br />6155 <br />915 <br /> <br />P,= <br /> <br />Subwatershed <br />ID <br />1 <br />2 <br />3 <br />4 <br />5 <br />6 <br />7 <br />8 <br />9 <br />10 <br /> <br />* Lag Time = 06(T cl <br />-Channel Velocity based on a trapezoidal channel with a <br /> <br />side slopes, 300cfs, and a Mannings coell of 0.05. <br /> <br />2' base width, 3: <br /> <br />Red Canyon HEC-HMS SCS Hydrologic Parameters <br />Subbasin Curve Number Calculations <br /> <br />Composite <br />SCS <br />Curve No. <br /> <br />9 <br /> <br />86 <br />88 <br />87 <br />88 <br />70 <br />72 <br />88 <br />79 <br />79 <br />79 <br /> <br />y, <br />Type-D <br />Soils <br />100 <br />100 <br />100 <br />100 <br /> <br />Type <br /> <br />y, <br />Type-C <br />Soils <br /> <br />Soi <br /> <br />y, <br />Type-B <br />Soils <br /> <br />100 <br />100 <br /> <br />y, <br />T ype-A <br />Soils <br /> <br />Rock (Natural <br />Desert <br />Landscaping) <br />73 <br />100 <br />85 <br />98 <br />50 <br />61 <br />70 <br />19 <br /> <br />Land Use <br /> <br />% Rangeland <br />Pinyon-juniper <br />(Poor <br />Conditionl <br /> <br />27 <br />o <br />15 <br />2 <br />20 <br />9 <br /> <br />% Residential <br />(2 acres or <br />morel <br /> <br />30 <br />30 <br /> <br />y, Residential <br />(1/4 acre or <br />lessl <br /> <br />Total <br />Drainage <br />Area <br />(sq mil <br />635.2 <br /> <br />100 <br /> <br />50 <br />50 <br />50 <br /> <br />50 <br />50 <br />50 <br /> <br />30 <br />80 <br />100 <br />100 <br /> <br />224. <br />498.8 <br />518.8 <br />256.3 <br />349.1 <br />215.3 <br />202.6 <br />126.7 <br />10.2 <br /> <br />Subbasin <br />1 <br />2 <br />3 <br />4 <br />5 <br />6 <br />7 <br />8 <br />9 <br />10 <br />