SW6230901_Design Calculations_20231115 (5)

4D Site Solutions, Inc.
DITCH CALCULATIONS
NOTE:sheet only set up to handle Tc from 5 min to 30 min
A. Flow velocity<2.0 fps when discharging to wetlands B. Flow velocity<4.5 fps all other cases** C. Channel slope<5.0%for curb outlet swales
1960-Royal Farms Ph II
Rainfall Intensity
Storm Event
5-min 10-min 15-min 30-min
10-yr 7.94 6.35 5.36 3.88
25-yr 8.92 7.10 6.00 4.45
50-yr 9.64 7.67 6.47 4.88
100-yr 10.30 8.21 6.92 5.30
Tc
Drainage Impervious Grassed Storm Rainfall
Ditch No. C Kerby Kirpich Intensity Q(cfs)
Area(ac) Area(ac) Area(ac) Event(yr)
Total Tc Tc Used (m/hr)
L(ft) n s Toy L(ft) S Teh
1 2.98 0.69 2.29 0.45 n/a 1024.0 0.005 12.47 12.47 10 10-yr 6.35 8.52
2 1.51 0.35 1.16 0.45 n/a 850.0 0.005 10.81 10.81 10 10-yr 6.35 4.31
3 0.17 0.05 0.12 0.50 n/a 260.0 0.005 4.34 4.34 5 10-yr 7.94 0.67
4 0.62 0.19 0.43 0.50 n/a 900.0 0.003 13.75 13.75 15 10-yr 5.36 1.66
5 0.76 0.23 0.53 0.50 n/a 1050.0 0.003 15.48 15.48 15 10-yr 5.36 2.04
6 0.20 0.06 0.14 0.50 n/a 260.0 0.005 4.34 4.34 5 10-yr 7.94 0.79
7 0.42 0.10 0.32 0.45 n/a 350.0 0.005 5.46 5.46 5 10-yr 7.94 1.50
8 11.69 1.80 9.89 0.40 n/a 2150.0 0.003 26.88 26.88 30 10-yr 3.88 18.14
9 2.73 0.42 2.31 0.40 n/a 1300.0 0.003 18.24 18.24 15 10-yr 5.36 5.85
10 14.64 2.25 12.39 0.40 n/a 2400.0 0.003 29.25 29.25 30 10-yr 3.88 22.72
printed: 11/15/2023 7:11 AM Page 1 of 1