Laserfiche WebLink
APPENDIX 2.05.3-1OB (Continued) <br />r~ <br />L <br />• <br /> <br />Assume ditch has .5 foot freeboard <br />Area = z y2 = 2(.5)2 = .50 <br />S = .065 ft/ft <br />n = .035 <br />Q = ~~ (.5)(.44) ~ (.065) <br />Q = ~~ (.5)(.58)(.25) <br />Q = 3.09 cfs <br />A designed triangular ditch will convey 3.1 cfs and will, therefore, convey the <br />10-year, 24-hour peak flow of 2.6 cfs. Therefore, the inside haul road ditch <br />will be 1 foot deep and 4 feet at the top. This design allows for a .5 foot of <br />freeboard to provide a margin of safety to convey surface water runoff. <br />- 305 - <br />(Rev. 5/86) <br />