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Figure 32 <br />Permanent Diversion Structures <br />Grass Lined Channel <br />n=0.7@6fps <br />n=.12@2fps <br />0.3~Min. Freeboard <br />w <br />1 z <br />1 <br />Precipitation Evem = 100-yr., 24-hr. <br />Rainfall = 2.7 inches <br />Ditch 1a repair segment is a rip-rap channel <br />D50 = 9.0 inches <br /> Maximum Slope Minimum Slope <br /> Watershed CN Runoff ~ W z s V d s V d <br />Ditch acres av inches cfs ft ft:ft ft/ft f s ft ft/ft f s ft <br />is 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 />1b 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 />References: <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 Revised 08/23/93 <br />