Laserfiche WebLink
<br />. <br />. <br />. <br />. <br />. <br />. <br />. <br />. <br />. <br />. <br />. <br />. <br />. <br />. <br />. <br />. <br />. <br />. <br />. <br />. <br />. <br />. <br />. <br />. <br />. <br />. <br />. <br />. <br />. <br />. <br />. <br />. <br />. <br />. <br />. <br />. <br />. <br />. <br />. <br />. <br />. <br />. <br />. <br />. <br />. <br />. <br />. <br />. <br />. <br />. <br />. <br />. <br />. <br />. <br />. <br />.. <br /> <br />Hvdroloav Calculations <br />Town of Granby <br />Basin A3 <br /> <br />SCS TR-55 Methodoloav <br />Q = (P-0.2S)'/(P+0.8S) <br />S=(1000ICN)-10 <br />qp = QuAQ <br /> <br />where: <br />Q = runoff depth (inches) <br />S = potential abstraction <br />CN = SCS Curve Number <br />A = drainage area (acres) <br />P = rainfall depth (Inches) <br />Q u = Unit Peak Discharge (cfslsmlin) <br /> <br />Catchment Data <br />Location I Westem Colorado (II) <br />Catchment I D = <br />Basin Area, A = <br />NRCS Soli Type = <br />Overland Flow Type <br />Runoff Depths <br />Storm <br />Rainfall Frequency (years) <br />Rainfall Duration (hours) <br />Rainfall Depth, P (inches) <br /> <br /> <br />Weighted Curve Numbers, CN <br />Sub-Area <br />1 <br />2 <br />3 <br />4 <br />Sum <br /> <br />Percent <br />0% <br />0% <br />83% <br />2% <br />85% <br /> <br /> <br />Description <br />Residential <br />Commercial <br />Pasture <br />Roads <br /> <br />Total Runoff <br /> <br />Storm 5 yr - 24 hr 10yr - 24 hr SOyr-24hr 100yr-24hr <br />Potential Abstration, S 2,S9 2.S9 2.S9 2.S9 <br />Runoff Depth, Q (inChes) 0.22 0.32 0.79 0.93 <br /> <br />Time of Concentration <br />Overland Flow <br />From Figure 3-1, TR-SS <br /> <br />Channel Flow <br />T" = U(1.49/n)R213 S 112 <br /> <br />where: <br />R = Hydraulic Radius n = Roughness Coeff. <br />S = Channel Slope L = Length of Flow <br />T co = Time of Concentration, Channel Flow <br /> <br />Basin Calculation <br /> <br /> <br />V Too or Tee <br />(IVs) (min) <br />1,S 7.6 <br />3.2 3.9 <br />2.1 11.4 <br /> <br />Flow <br />Reach T e <br />Adv~tl.ao.d ~.. <br />B chann~1 !:!~ <br />C .:Cha6b~1 c.; <br />o <br />Total <br /> <br />Peak Dlscharae <br /> <br /> <br />8/20/02 <br />TRSS-hydrology.xls <br />