SW6240103_Design Calculations_20240425 (4)

4D Site Solutions, Inc.
DITCH CALCULATIONS
1997-Brayden Preserve Subdivision
Rainfall Intensity
Storm Event
5-min 10-min 15-min 30-min RunoffCoeff.
10-yr 7.82 6.25 5.28 3.82 Impervious 0.95
25-yr 8.69 6.92 5.85 4.33 Grassed 0.30
50-yr 9.32 7.43 6.27 4.72
100-yr 9.92 7.89 6.65 5.09
Tc
Drainage Impervious Grassed Storm Rainfall
Ditch No. C Kirpich Intensity Q(cfs)
Area(ac) Area(ac) Area(ac) Event(yr)
Total Tc Tc Used (m/hr)
L(ft) S To,
1 0.72 0.17 0.56 0.45 230.0 0.0345 1.88 1.88 5 10-yr 7.82 2.54
2 0.99 0.15 0.84 0.40 477.0 0.016 4.41 4.41 5 10-yr 7.82 3.09
3 1.47 0.23 1.24 0.40 949.0 0.016 7.46 7.46 5 10-yr 7.82 4.60
4 2.32 0.54 1.78 0.45 1481.0 0.016 10.71 10.71 10 10-yr 6.25 6.53
5 5.35 0.82 4.53 0.40 2251.0 0.013 16.06 16.06 15 10-yr 5.28 11.30
6 8.18 1.26 6.92 0.40 2878.0 0.014 18.49 18.49 20 10-yr 4.79 15.68
7 8.69 1.34 7.35 0.40 3267.0 0.013 20.99 20.99 20 10-yr 4.79 16.66
8 0.23 0.05 0.18 0.45 286.0 0.016 2.97 2.97 5 10-yr 7.82 0.81
9 0.15 0.06 0.09 0.55 229.0 0.005 3.92 3.92 5 10-yr 7.82 0.65
10 2.08 0.48 1.60 0.45 1076.0 0.011 9.62 9.62 10 10-yr 6.25 5.85
11 0.11 0.04 0.07 0.55 159.0 0.006 2.81 2.81 5 10-yr 7.82 0.47
12 0.18 0.07 0.11 0.55 251.0 0.006 3.88 3.88 5 10-yr 7.82 0.77
13 4.09 0.94 3.15 0.45 2332.0 0.013 16.17 16.17 15 10-yr 5.28 9.72
14 1.51 0.58 0.93 0.55 2176.0 0.013 15.21 15.21 15 10-yr 5.28 4.39
15 1.16 0.18 0.98 0.40 427.0 0.018 3.91 3.91 5 10-yr 7.82 3.63
16 1.14 0.18 0.96 0.40 207.0 0.007 3.19 3.19 5 10-yr 7.82 3.57
17 1.61 0.25 1.36 0.40 624.0 0.011 6.24 6.24 5 10-yr 7.82 5.04
18 0.30 0.12 0.18 0.55 408.0 0.014 4.09 4.09 5 10-yr 7.82 1.29
19 1.19 0.46 0.73 0.55 1724.0 0.013 12.94 12.94 15 10-yr 5.28 3.46
20 0.77 0.30 0.47 0.55 1091.0 0.016 8.30 8.30 10 10-yr 6.25 2.65
21 0.41 0.16 0.25 0.55 561.0 0.016 4.98 4.98 5 10-yr 7.82 1.76
22
23
printed:4/25/2024 4:52 PM Page 1 of 2

4D Site Solutions, Inc.
Ditch No. infll
Drainage Impervious Grassed C Kirpich Tc Storm Intensity Q(cfs)
Area(ac) Area(ac) Area(ac) L(ft) S To Total Tc Tc Used Event(yr) (ice)
24 2.68 0.62 2.06 0.45 1067.0 0.017 8.05 8.05 10 10-yr 6.25 7.54
25 1.98 0.61 1.37 0.50 987.0 0.016 7.69 7.69 10 10-yr 6.25 6.19
26 1.55 0.24 1.31 0.40 612.0 0.0131 5.80 5.80 5 10-yr 7.82 4.85
27 0.00 0.00 #DIV/0! n/a 0.00 5 10-yr 7.82 0.00
printed:4/25/2024 4:52 PM Page 2 of 2