Laserfiche WebLink
Labco Auto 13odytRepair Facility <br />Drainage Report May 20, 1993 <br />Page 8 <br />A2. Detention Volume Calculations <br />Required Detention Volume: 1121 cf. <br />Storage Depth Available: <br />North MH 631.99 - 628.09 = 3.90 ft <br />South Central MH 631.99 - 628.30 = 3.69 ft <br />South West MH 631.99 - 628.64 = 3.35 ft <br />South East MH 631199- 628151 = 3.48 ft <br />Total Depth ` =14.42 ft <br />Detention Volume From Manholes = (TTxd2xD)/4 <br />d = 4.5 feet <br />D = total depth (ft) <br />Detention Volume From Manholes <br />Detention Volume From 36" pipe <br />Detention Volume From 12" pipe <br />Detention Volume From 18" pipe <br />Total Detention Volume Provided <br />A3. Orifice Sizing <br />Orifice 41, 5 year return frequency storm: <br />=3.1415x5.08x14.42=229cf <br />=3.1415x7.08x118 '=820cf <br />= 3.1415 x 0.25 x 30 = 24cf <br />= 3.1415 x 0.56 x 42 = 74d <br />=1,147 cf > 1121 d Q& <br />Peak discharge (Q) = 0.21(Lawns & landscaping) x 0.58 = 0.1218 cfs <br />Elev. 027.10 <br />IE out 629.10 <br />Overflow 632.64 <br />Height (H)= 632.64 - 629.10 = 3.54 ft A. <br />Q = 0.62a(2GH)112, <br />a = (TTd20mc4)/4 <br />a = cross -sectional orifice area <br />G = gravitational constant of 32.2 b^-R/,,,= <br />d„l,,= orifice diameter (feet) <br />IUITU ..a:•,�-� <br />