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<br />Culvert C-2 <br /> <br />Trial configuration -18-in-diameter CSP, which has a rated flow, Q = 5.70 cfs <br />5.70 cfs > 1.58 cfs, Q culvert > Q drainage, trial culvert is adequate <br />Ditch D-6 <br />Trial configuration - V-ditch, 2-ft-deep, 2:1 side slope, unlined, assumed velocity = 3 fps <br />Overland flow time for Area 6 (0.46 acre), which contributes to Ditch D-6, is 16 min <br />The ditch flow time: <br />t =length/velocity = 136 ft/(3 ft/sec X 60 sec/min) = 0.76 min <br />Total flow time = 16 + 0.76 = 16.76 min <br />Rainfall intensity: <br />For Region 6 <br />I =(210)/(16.76+ 26) = 4.91 in/hr <br />For Region 7 <br />I =(77)/(16.76+10) = 2.88 in/hr <br />I average = 3.90 in/hr <br />The discharge for Area D-6 using the Rational Formula: <br />Q = (0.50) (3.90 in/hr) (0.46 acre) = 0.90 cfs <br />The rated discharge for the trial ditch using Manning's Equation: <br />The properties of a 2-ft-deep, 2:1 side slope ditch: <br />A=bh=(2ft)(4ft)=8fY , <br />P=2(2'+4')°'S=8.94 ft ~'k,y 15 a <br />R=A/P=Bft'/8.94ft=0.89ft ~~~ pr <br />The slope of Ditch D-1 is 0.007% .~i7 f <br />~~ ~~t <br />Q = (1.486/n) A R =" S "~ ~~ ,~ 5 ~~'''`~`' <br />Q = (1.486/0.025) 8 ft' (0.89 ft)"' (0.007)"= ~a5 <br />Q = 36.81 cfs <br />36.81 cfs > 0.90 cfs, Q ditch > Q drainage, trial ditch is adequate <br />Culvert C-3 <br />~~1~~~~ <br />~ rl <br />e l~c~~. <br />5` t~~~c~ Jp_/S~r~ <br />Trial configuration -18-in-diameter CSP, which has a rated flow, Q = 5.70 cfs <br />5.70 cfs > 0.90 cfs, Q culvert > Q drainage, trial culvert is adequate <br />-,-. <br />Summary o(Kvaerner Calculations <br />Piceance Sile Diversion Ditch System <br />Technical Revision Mining and Reclamation Permi[ <br />