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C TIME OF CONCENTRATION FOR: <br /> EVERETT SCHOOL DISTRICT BUS FACILITY <br /> CITY OF EVERETT <br /> EXISTING CONDITIONS <br /> Sheet Flow. T,= 0.42(n,l.)aa <br /> w2)oa(so)a <br /> Where: T,: travel time(min). <br /> n,: sheet flow Mannings Effective roughness coefficient(fmm Table 6.1). <br /> L: low length(fl). <br /> Pr: 2-year,24-hour rainfall(in),(sce'rable E.l). <br /> so: slope of hydraulic grade line(land slope,Nt). <br /> Shallow T,= 1. <br /> Concentrated Flow. 60py(so)o s <br /> Micro: T,: travel time(min). <br /> L: low length(fl). <br /> k,: time of concentration velocity factor(Ns),(see Table 6.1). <br /> so: slope of hwlmulic grade line(land slope,JIM). <br /> / Channel Flow. T,= 1. <br /> 1, 60kd9„)os <br /> where: T,: travel time(min). <br /> 1.: flow length(fl). <br /> k,: time of concentration velocity factor(Ns).(see Table G.1). <br /> s,: slope of hydruulic grade line(land slope,NII). <br /> CALCULATIONS: <br /> Shect Flow: Segment 0= 1 T,= 11.4764 min. <br /> n,= 0.05 <br /> 1.= 300 <br /> change El.= 10 <br /> 1't= 1.55 <br /> %= 0.0333 <br /> Shallow Segment 0= D',= 4.93508 min. <br /> Concentrated Flaw. 1.= 1 0 <br /> change EI.= 5 <br /> k,= 13 <br /> y= 0.0119 <br /> T,- 13.73 mhs. <br /> Pap I <br />