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DITCH CALCULATION <br /> (Using Chezy-Manning Equation) <br /> PROJECT: Premier Co-op Grain Bin 2015 <br /> FILE NUMBER: PC-03-15 <br /> LOCATION: Swale A <br /> Enter the channel characteristics (see Diagram 1): <br /> CHANNEL CROSS SECTION <br /> Minimum Channel Slope(S): 0.20 feet/feet <br /> 100 Year Design Flow(Q): 2.05 CFS <br /> Bottom Width(W): 2 feet <br /> Avg. Side Slope(X): 3 horiz./vert. _ !- <br /> Depth of Channel(Y): 1 feet ! ,=1117-1 <br /> Retardance Class: D !! =''' <br /> Manning's Number(N): 0.05 r _ __ <br /> i!-i i!-1! !-T!=!i . <br /> T i!-iii <br /> The channel will behave as follows: W <br /> Hydraulic Radius(R): 0.16 feet <br /> Depth (D): 0.20 feet Diagram 1 <br /> Velocity(V): 3.93 feet/second <br /> 100 Year Peak Flow Rate: <br /> Using the Rational Method: <br /> Qioo=CIA: 0.39 8.1 0.65 = 2.05 cfs <br /> C = 0.39 Open Space, hydrologic soil group"D", Slope Range z 6%; <br /> I = 8.1 in/hr per Madison rainfall intensity; <br /> A= 0.65 acres; <br /> *The rational method runoff coefficients and rainfall intensity were determined using the <br /> Wisconsin Department of Transportation Facilities Development Manual Procedure 13-10-5 <br /> Figures 2 and 4. <br /> Designed By: AFF <br /> Date: 5/26/2015 <br /> Checked By: <br /> Date: <br /> Stormwater Submittal <br /> PC-03-15 <br /> 5/26/2015 Exhibit#3-2 <br />