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<br />(7) Compute each hourly increment of <br />direct runoff using CN = 88, <br />AMC-II1, and hydrologic soil group <br />B minimum retention loss rate of <br />0.06 inches per 15-minute interval <br />or 0.24 inches per hour (Table A-lO, <br />Appendix A, Page 544) <br /> <br />Direct Runoff Increments for Computing Maximum Probable Flood General Type Storm <br />(Values in inches) <br /> <br />Time lncremental Accumulative <br />Ending Design Design 1 IncrementaI <br />Hr. Rainfall Rainfall Accum. Incremental Loss <br /> 1 0.36 0.36 0.00 0.00 0.36 <br /> 2 0.30 0.66 0.08 0.06 0.24 <br />. 3 0.35 1.01 0.28 0.11 0.24 <br /> 4 0.42 1.43 0.55 0.18 0.24 <br />." -, <br /> 5 0.30 1. 73 0.80 0.06 0.24 <br /> 6 0.42 2. IS 1.10 0.18 0.24 <br /> 7 0.42 2.57 1.48 O. 18 0.24 <br /> 8 0.48 3.05 1.90 0.24 0.24 <br /> 9 0.53 3.58 2.35 0.29 0.24 <br /> 10 0.66 4.24 3.00 0.42 0.24 <br /> 11 1.01 5.25 3.90 0.77 0.24 <br /> 12 2.87 8.12 6.65 2.63 0.24 <br /> 13 0.21 8.33 6.90 O.OJ 0.21 <br /> 14 0.21 8.54 7.05 0.00 0.21 <br /> 15 0.21 8.75 7.25 0.00 0.21 <br /> 16 0.21 8.96 7.45 0.00 0.21 <br /> 17 0.21 9.17 7.65 0.00 0.21 <br /> 18 0.20 9.37 7.85 0.00 0.20 <br />1 Using CN =88, AMC-III, Figure A-4, Appendix A, Page 541 <br />2 Computation by CN 88 gives 0.08 inch per hour. Abandon curve and <br /> use 0.24 inch per hour for 1 hour storm increments. <br /> <br />.' <br /> <br />- 22 - <br />