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JBird Mine Stormwater Design-TR55 Model Stormwater Channel Data <br />Jbird Stormwater Design <br />Rainfall 3 inches 100yr24hr event <br />Open Channel Flow Design <br />SW run-on and runoff Controls <br />Mannings Equations <br />Q = (Kn A R^0.67 5^0.5) /n <br />Q= flow cult/s <br />Kn = 1.486 dimensionless coefficient <br />A = x-sect area sqft <br />R = hyd. Rad. It <br />R = A/P ft <br />P = wetted per. ft <br />5 = slope ft/ft <br />n = mannings dimensionless coefficient <br />Run-on Channel parameters Scenario 1 <br />A= 2 sgft <br />P = 4.472 <br />R = 0.4472272 <br />S = 0.033 <br />n = 0.02 bare soil 0.5ft-2.0ft deep <br />Q= 15.744529 cuft/s <br />Q is greater than cis needed from Area 1 to convey 100yr24hr flow <br />Corresponding Run-on Channel Parameters (V-ditch) <br />Depth 1 ft <br />Top Width 4 ft <br />Slope Length 2.236 ft 2:1 slope on sides <br />Run-on Channel parameters <br />Apply same run-on channel parameters to all areas <br />Q is greater than cfs needed from all subareas to convey 300yr24hr flow <br />Run-on Channel parameters Scenario 2 <br />A = 1 sgft <br />P = 2.236 <br />R = 0.4472272 <br />S = 0.033 flatest slope for all runoff channels (conservative) <br />n = 0.02 bare soil 0.5ft-2.0ft deep <br />Q = 7.8722645 cuft/s <br />Q is greater th an cfs needed from all areas to convey 300yr24hr flow <br />Corresponding Run-on Channel Parameters (V-ditch) <br />Depth 0.5 It <br />Top Width 2 ft <br />Slope Length 1.118 ft 2:1 slope on sides <br />JBird Mine Stormwater Design 01/13/09 Gault Group Inc.