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• • <br />Figure 32 <br />Permanent Diversion Structures <br />Grass Lined Channel <br />n=0.7Q6fps <br />n=.12Q2ips <br />0.3~Min. Freeboard Precipitation Event = 100-yr., 24-hr. <br />---~-:- Rainfall = 2.7 inches <br />o ~ '/~ 1 Ditch 1a repair segment is a rip-rap channel <br />~ D50 = 9.0 inches <br />~ w -+I z <br />._ <br />cn <br />W <br /> Maximum Slo_~e Minimum Sloee <br /> Watershed CN Runoff O W z s V d s V d <br />Ditch acres av inches ds ft ft:ft ft/ft f s ft Wft f ft ~ <br />1a Repair 752 77 0.81 395.3 8 3:1 0.06 9.8 2.5 -- -- -- <br />1 a• 752 77 0.81 395.3 8 2:1 0.067 8.4 3.1 0.029 5.2 4.3 <br />1 b 42 87 1.48 71 2 2:1 0.17 8.3 1.7 0.06 4.7 2.3 <br />2a 36.5 82 1.15 55 4 2:1 0.10 6.1 1.3 0.005 1.4 3.6 <br />2b-1 340 65 0.38 65 6 2:1 use minimum 0.005 1.4 3.5 <br />2b-2 95 77 0.87 88 6 2:1 use minimum 0.005 1.5 4.0 <br />(1) 'Peak Flows in Colorado' -Soil Conservation Service, March, 1977. <br />(2) 'Design Charts for Open Channel Flow' - U.S. Department of Transportation, November, 1977. <br />• Util¢es previously approved channel parameters based upon higher peakflow value <br />TR 93-35 <br />Revised 08/23/93 <br /> <br />