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#10 <br />WILLIAM CLRICH DRAINAGE CALCULATIONS <br />A. Drainage Area of pond before construction: 6.62 acres <br />Drainage Area of pond after construction: 7.86 acres - 342.382 sq. ft. <br />I. Original Runoff 100 year storm Tc - 5 minutes <br />Cbefore - 0.35 <br />Qbefore - CiA - (0.35)(9.3)(6.62) 21.5 CFS <br />II. New Runoff Factor into Pond: <br />Additional Driveway: 2680 sq. ft. x 0.90 - _.l_ <br />Additional House Roof: 4284 sq. ft. x 1.00 - 4284 <br />Additional Concrete Apron 6 Sidewalk: 185 sq. ft. x 1.00 - 185 <br />Remaining Area: 335,233 x 0.35 - 117,332 <br />342,382 x 0.36 - 124,213 <br />III. New Runoff: - (0.36)(9.3)(7.86) - 26.3 CFS <br />IV. Stage - Storage Table: <br />ELEV WATER LEVEL (FT) AREA (FT2) INC. VOL (FT3) ACCUM VOL (FT3) <br />930.0 <br />0 <br />2.,188 <br />0 <br />931.0 <br />1.0 <br />30,048 <br />26,668 <br />16,668 <br />932.0 <br />�.0 <br />36,420 <br />,324 <br />59,902 <br />933.0 <br />-?.0 <br />46,-'28 <br />41 ,324 <br />101,226 <br />V. <br />Stage - Discharge Table: <br />Existing <br />12" C.M.P. with <br />inlet control <br />ELEV <br />WATER LEVEL (FT) <br />HW/D <br />(CFS) <br />930.0 <br />0 <br />0 <br />931.0 <br />1 <br />1 <br />1.6 <br />93_.0 <br />933.0 <br />3 <br />3.4 <br />