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MAPLE ST <br /> Section 6 Conveyance Design <br /> The proposed onsite storm system will consist of 6-in storm pipe and footing drains which runoff the portion of <br /> roof area will be conveyed to the onsite dispersion system located in the east side of the site. <br /> The 6-inch conveyance system was sized using the Rational Method and Manning's Equation. For the rational <br /> method equation,the peak flow rate was calculated using the characteristic of the areas tributary to the 6-inch <br /> conveyance system. The peak flow, tributary to the 6-inch conveyance system, is 0.19 cfs for the 100-year storm <br /> event.The capacity for the 6-inch conveyance system was calculated using Manning's Equation. Using Manning's <br /> equation,a 6-inch pipe at 2%has capacity to convey 0.849 cfs.Therefore,the proposed 6-inch conveyance system <br /> has adequate capacity to convey the 100-year storm.Please see the calculations for the conveyance system below <br /> and on the following pages. <br /> Rational Method,Per KCSWDM Section 3.2.1 <br /> Q=CIA(cfs) <br /> C= Runoff Coefficient(Weighted Average) <br /> C=0.90 for pavement and roofs <br /> C=0.25 for lawns <br /> Weighted C Determination <br /> C _ 0.90(0.05 ac)+0.25(0.06 ac) _ 0.57 <br /> 0.11 ac <br /> I = Peak Rainfall Intensity=PRIR=2.86 <br /> PR=3.5 inches(100-year, 24-hour runoff) <br /> IR=aRTC"= <br /> aR =2.61 (100-year) <br /> bR =0.63 (100-year) <br /> Tc =Time of concentration(6.3 minutes minimum) <br /> A= Basin Area (acres)=0.11 ac <br /> QR=C I A= (0.57)(2.86)(0.11 acres) =0.19 cfs <br /> JOB#19-336 <br /> Storm Drainage Report 6.1 <br />