SW6220806_Design Calculations_20221128 (13)

CALCULATIONS
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*
Storm Event
Rainfall Intensity
5-min
10-min
15-min
30-min
10-yr
7.92
6.33
5.34
3.87
25-yr
8.94
7.12
6.02
4.46
50-yr
1 9.65
7.68
6.49
4.89
100-yr
1 10.30
8.23
6.93
5.31
C. Channel slope < 5.0% for curb outlet swales
Drainage
Impervious
Grassed
Tc
Storm
Rainfall
Ditch No.
C
Kerby
Kirpich
Intensity
Q (cfs)
Area (ac)
Area (ac)
Area (ac)
Event (yr)
Total Tc
Tc Used
(in/hr)
L (ft) n s
Tov
L (ft)
S
Tce
1
0.58
0.13
0.45
0.45
n/a
340.0
0.006
4.97
4.97
5
10-yr
7.92
2.07
2
3.40
0.26
3.14
0.35
n/a
900.0
0.012
8.06
8.06
10
10-yr
6.33
7.53
3
0.45
0.10
0.35
0.45
n/a
275.0
0.005
4.53
4.53
5
10-yr
7.92
1.60
4
2.95
0.68
2.27
0.45
n/a
700.0
0.012
6.64
6.64
5
10-yr
7.92
10.50
5
0.78
0.18
0.60
0.45
n/a
550.0
0.006
7.20
7.20
5
10-yr
7.92
2.78
6
3.19
0.74
2.45
0.45
n/a
1000.0
0.012
8.74
8.74
10
10-yr
6.33
9.08
7
4.01
0.93
3.08
0.45
n/a
1100.0
0.012
9.41
9.41
10
10-yr
6.33
11.42
8
0.27
0.08
0.18
0.50
n/a
250.0
0.005
4.21
4.21
5
10-yr
7.92
1.06
9
3.87
0.89
2.97
0.45
n/a
720.0
0.012
6.79
6.79
5
10-yr
7.92
13.78
10
0.58
0.13
0.44
0.45
n/a
315.0
0.010
3.85
3.85
5
10-yr
7.92
2.05
11
1.12
0.26
0.86
0.45
n/a
315.0
0.010
3.85
3.85
5
10-yr
7.92
4.00
12
1.61
0.37
1.24
0.45
n/a
650.0
0.010
6.73
6.73
5
10-yr
7.92
5.74
13
1.87
0.43
1.44
0.45
n/a
650.0
0.010
6.73
6.73
5
10-yr
7.92
6.66
14
0.64
0.15
0.49
0.45
n/a
250.0
0.015
2.76
2.76
5
10-yr
7.92
2.28
15
1.32
0.30
1.01
0.45
n/a
450.0
0.012
4.73
4.73
5
10-yr
7.92
4.70
16
0.15
0.05
0.11
0.50
n/a
130.0
0.015
1.67
1.67
5
10-yr
7.92
0.60
17
0.12
0.04
0.08
0.50
n/a
100.0
0.030
1.04
1.04
5
10-yr
7.92
0.48
18
0.10
0.03
0.07
0.50
n/a
100.0
0.030
1.04
1.04
5
10-yr
7.92
0.39
19
0.22
0.05
0.17
0.45
n/a
100.0
0.010
1.59
1.59
5
10-yr
7.92
0.79
20
0.22
0.05
0.17
0.45
n/a
100.0
0.010
1.59
1.59
5
10-yr
7.92
0.77
21
0.41
0.09
0.32
0.45
n/a
350.0
0.013
3.78
3.78
5
10-yr
7.92
1.47
22
0.68
0.16
0.52
0.45
n/a
450.0
0.018
4.09
4.09
5
10-yr
7.92
2.41
23
0.82
0.19
0.63
0.45
n/a
450.0
0.018
4.09
4.09
5
10-vr
7.92
2.91
pnMed: 11/28/20221:37 PM Page 1 of 2

Ditch No.
Drainage
Area (ac)
hnpervious
Area (ac)
Grassed
Area (ac)
C
Kerby
L (ft) n s
T.,F
)
Kirpich
S
T h
Total Tc
Tc Used
Storm
Event (yr)
Intensity
(in/hr)
Q (cfs)
24
1.70
0.39
1.31
0.45
n/a
450.0
0.018
4.09
4.09
5
10-yr
7.92
6.07
25
0.48
0.11
0.37
0.45
n/a
230.0
0.033
1.91
1.91
5
10-yr
7.92
1.70
26
0.37
0.09
0.29
0.45
n/a
230.0
0.033
1.91
1.91
5
10-yr
7.92
1.33
27
0.18
0.04
0.14
0.45
n/a
130.0
0.007
2.24
2.24
5
10-yr
7.92
0.63
28
0.09
0.04
0.06
0.55
n/a
130.0
0.007
2.24
2.24
5
10-yr
7.92
0.40
29
4.97
1.15
3.82
0.45
n/a
500.0
0.016
4.59
4.59
5
10-yr
7.92
17.72
30
0.22
0.05
0.17
0.45
n/a
150.0
0.027
1.48
1.48
5
10-yr
7.92
0.77
31
0.11
0.02
0.08
0.45
n/a
150.0
0.027
1.48
1.48
5
10-yr
7.92
0.37
32
2.27
0.52
1.74
0.45
n/a
690.0
0.009
7.34
7.34
5
10-yr
7.92
8.08
33
0.93
0.21
0.71
0.45
n/a
690.0
0.009
7.34
7.34
5
10-yr
7.92
3.30
34
1.04
0.24
0.80
0.45
n/a
600.0
0.007
7.26
7.26
5
10-yr
7.92
3.69
35
0.27
0.10
0.16
0.55
n/a
350.0
0.005
5.46
5.46
5
10-yr
7.92
1.16
36
0.31
0.07
0.24
0.45
n/a
220.0
0.012
2.72
2.72
5
10-yr
7.92
1.11
37
0.15
0.06
0.09
0.55
n/a
220.0
0.012
2.72
2.72
5
10-yr
7.92
0.66
38
3.13
0.72
2.41
0.45
n/a
1045.0
0.011
9.35
9.35
10
10-yr
6.33
8.91
39
0.37
0.08
0.28
0.45
n/a
200.0
0.005
3.55
3.55
5
10-yr
7.92
1.31
40
0.30
0.07
0.23
0.45
n/a
200.0
0.005
3.55
3.55
5
10-yr
7.92
1.06
41
0.73
0.17
0.56
0.45
n/a
370.0
0.013
3.94
3.94
5
10-yr
7.92
2.60
42
0.71
0.16
0.54
0.45
n/a
370.0
0.013
3.94
3.94
5
10-yr
7.92
2.52
43
1.32
0.30
1.01
0.45
n/a
570.0
0.013
5.50
5.50
5
10-yr
7.92
4.69
44
1.28
0.30
0.99
0.45
n/a
560.0
0.013
5.42
5.42
5
10-yr
7.92
4.57
45
0.08
0.03
0.05
0.55
n/a
100.0
0.030
1.04
1.04
5
10-yr
7.92
0.34
46
0.16
0.06
0.10
0.55
n/a
100.0
0.030
1.04
1.04
5
10-yr
7.92
0.71
47
6.53
1.51
5.02
0.45
n/a
1000.0
0.008
10.22
10.22
10
10-yr
6.33
18.60
48
5.89
1.36
4.53
0.45
n/a
1000.0
0.010
9.38
9.38
10
10-yr
6.33
16.77
panted: 11/28/20221:37 PM Page 2 of 2