DRAINAGE AREA =20,650 SQ. FT. = 0.474 ACRES <br />AVERAGE RUNOFF COEFFICIENT (C) =0.71 <br />LENGTH OF DRYWELL = 15 FEET <br />WIDTH OF DRYWELL = 16 FEET <br />DEPTH OF DRYWELL = 6 FEET <br />VOID RATIO OF DRYWELL =30% <br />AVERAGE PERMEABILITY OF SOIL =20.00 INCHES/HR <br />SURFACE AREA OF BOTTOM =240 SQ. FT. <br />SURFACE AREA OF SIDES =372 SQ. FT. <br />OUTFLOW CAPACITY OF DRYWELL =400.0 CU. FT./HR = 49.87 GALLONS PER MINUTE <br />MAXIMUM STORAGE CAPACITY OF DRYWELL = 432 CU. FT. OF WATER <br />DRYWELL VOLUME = 53.3 CUBIC YARDS <br />5 YEAR TOTAL <br />RECURRENCE RAINFALL TOTAL OUTFLOW <br />DURATION DURATION RAINFALL DURING STORM EVENT FROM STORAGE <br />OF STORM OF STORM INTENSITY STORM RUNOFF DRYWELL REQUIRED DRYWELL <br />IN MINUTES IN HOURS IN/HR INCHES CU. FT. CU. FT. CU. FT. SIZING <br />5 0.08 2.50 0.21 256 33 222 OK <br />10 0.17 1.95 0.33 399 67 332 OK <br />15 0.25 1.42 0.36 436 100 336 OK <br />20 0.33 1.24 0.41 507 133 374 OK <br />30 0.50 1.00 0.50 614 200 414 OK <br />60 1.00 0.64 0.64 785 400 385 OK <br />120 2.00 0.48 0.96 1,178 800 378 OK <br />180 3.00 0.42 1.26 1,546 1,200 346 OK <br />240 4.00 0.38 1.52 1,865 1,600 265 OK <br />360 6.00 0.35 2.10 2,577 2,400 177 OK <br />480 8.00 0.33 2.64 3,240 3,200 40 OK <br />600 10.00 0.28 2.80 3,436 4,000 EMPTY OK <br />720 12.00 0.24 2.88 3,534 4,800 EMPTY OK <br />900 15.00 0.19 2.85 3,497 6,000 EMPTY OK <br />1,080 18.00 0.18 3.24 3,976 7,200 EMPTY OK <br />1,260 21.00 0.17 3.57 4,381 8,400 EMPTY OK <br />1,440 24.00 0.15 3.60 4,418 9,600 EMPTY OK <br />Impervious 11,000 0.90 9,900 <br />Pervious 9,650 0.50 4,825 <br />TOTALS 20,650 0.71 14,725 <br />SOAKAGE TRENCH CALCULATIONS FOR <br />135 Kourt Dr. <br />See Infiltration Report by: <br />Attached <br />RUNOFF COEFICIENT