SW6220806_Design Calculations_20221128 (15)

CALCULATIONS
sheet only set up to handle Tc from 5 min to 30 min
A. Cross -pipes to use 25-yr storm inensity
Rainfall Intensity
rm Event 5-m
10-yr
7.92
6.33
5.34
3.87
25-yr
8.94
7.12
6.02
4.46
50-yr
9.65
7.68
6.49
4.89
100-yr
10.30
8.23
6.93
5.31
Tc
Drainage
Storm
Rainfall
Pipe No.
Area (ac)
C
Kerby
Kirpich
Event (yr)
Intensity
Q (cfs)
Total Tc
Tc Used
(in/hr)
L (ft) n s Tom
L (ft) S T,
1 13.90
0.45
n/a
1390.0
0.007
13.86
13.86
15
25-yr
6.02
37.66
2 4.99
0.45
n/a
720.0
0.012
6.79
6.79
5
25-yr
8.94
20.06
3 2.93
0.45
n/a
700.0
0.012
6.64
6.64
5
25-yr
8.94
11.79
4 1.59
0.45
n/a
450.0
0.011
4.89
4.89
5
25-yr
8.94
6.40
5 1.35
0.50
n/a
590.0
0.005
8.16
8.16
10
25-yr
7.12
4.79
6 2.37
0.45
n/a
390.0
0.017
3.70
3.70
5
25-yr
8.94
9.53
7 0.29
0.45
n/a
130.0
0.010
1.95
1.95
5
25-yr
8.94
1.15
8 0.48
0.45
n/a
170.0
0.005
3.13
3.13
5
25-yr
8.94
1.94
9 3.56
0.45
n/a
680.0
0.008
7.78
7.78
10
25-yr
7.12
11.40
10 4.65
0.45
n/a
770.0
0.008
8.36
8.36
10
25-yr
7.12
14.89
11 4.92
0.35
n/a
925.0
0.012
8.23
8.23
10
25-yr
7.12
12.26
printed: 11/28/2022 1:37 PM Page 1 of 1