Laserfiche WebLink
• <br />Pond Sizing <br />Water Volume <br />Sediment Volume <br />Total Volume <br />Hydraulic Calculations <br />(See Footnotes: 4,5,6 & 7) <br />Emergency Spillway Hydraulics <br />10 year, 24 hour Storm <br />10 year, 24 hour Storm <br />Q = 3.8cfs <br />V = (1.44/n)R2/3 S1/2 <br /> <br />Where <br />N = Mannings Roughness Coefficient <br />R = Hydraulic Radius <br />S = Channel Bottom Slope <br />Assume Grassed Spillway <br />N = 0.035 <br />Slope = .O1 ft/ft <br />Width = 20 ft <br />Depth = 0.2 ft <br />Velocity = 1.4 ft/sec <br />Culvert Sizing <br />Peak flow 10 year, 24 hour event = 3.Ocfs <br />0.20 ac-ft <br />0.02 ac-ft <br />0.22 ac-ft <br />From Culvert Nomograph, U.S. Bureau of Public Roads, using h/d = 1, <br />• projecting inlet, the peak flow from the watershed can be carried <br />in a 15 inch culvert. Using the same nomograph, it is found that a <br />-6- <br />