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..`• <br />2 NEST PORTAL <br />CUlYERT DESIGN <br />ww 29 ~ uwJl <br />0 RFG1~'~~ <br />i O~^°'.p°~t~FvF~~4 <br />~oj~'.'y0p' ~~x ,,, <br />i~ mJ ~ ~ <br />gs~~ .'kr'-~6-2~~9Z <br />South Area Undisturbed Drainage, 100-Year Event <br />2 West Portal Area, Powderhorn Coal Company <br />BASIN CHARACTERISTICS <br />.'• <br />~ • <br />DRAINAGE AREA (SQ. MI.) = 0.005 <br />STREAM LENGTH (MI.) = 0.124 <br />ELEVATION DIFFERENCE (FT,j = 288.000 <br />RUNOFF CARVE NUMBER, CN = 78.000 <br />MINIMUM INFILTRATION LOSS (IN./HR.) = 0.250 <br />PRECIPITATION FOR SPECIFIED STORM <br />ADJUSTED PRECIPITATION FOR SELECTED STORM (IN.) <br />UNIT HYDROGRAPH PARAMETERS <br />UNADJUSTED TIME OF CONCENTRATION (HR.) _ <br />ADJUSTED TIME OF CONCENTRATION (HR.) _ <br />DURATION OF EXCESS RAINFALL, D (HR.) _ <br />TIME TO PEAK (HR. ) _ <br />BASE TIME (HR. ) _ <br />QPEAK (PEAK FLOW IN CFS FOR UNIT HYDROGRAPH) _ <br />RESULTANT HYDROGRAPH VALUES <br />PEAK DISCHARGE (CFS) _ <br />RUNOFF VOLUME (ACRE-FEET) _ <br />TIME TO PEAK DISCHARGE (HR) _ <br />2.20 <br />0.03 <br />0.03 <br />0.00 <br />0.02 <br />0.05 <br />127.6 <br />3.02 <br />0.08 <br />12.00 <br />USED SCS TYPE II 24-HOUR GENERAL STORM <br />Culvert Design <br />Reference: Figure 4-18, Inlet Control ~4onogram for CMP, Page 161, <br />Handbook of Steel Drainage 8 Highway Construction Products, <br />American Iron and Steel Institute, 1971 <br />12" CMP with end section conforming to fill slope and a 1.50 headwater <br />depth to diameter will carry 4 CFS. Use 1 12" CMP <br />MISC -5 (New 8-28-92) <br />