SW6211001_Design Calculations (Q 100-Yr, Pond 1)_20220128

DESIGN REQUIREMENTS:
A. Pass the storm event
Drainage Area, (DA) = 3.16 acres
Intensity, (I) = 8.05 inches/hr
Composite Runoff Coefficient, (C) _> 0.30
Maximum Release Rate, (Q100) _> 7.63 cfs
Drainage Area, (DA) = 6.90 acres
Intensity, (I) = 10.10 inches/hr
Composite Runoff Coefficient, (C) _> 0.71
Peak Release Rate, (Q100) _> 49.48 cfs
Contour
Elev.
00
Contour
Area
(sf)
Incr.
Storage
(cf)
Accum.
Storage (S)
(cf)
Stage
(Z)
00
In (S)
In (Z)
Z est
249.7
9,652
-
-
-
-
250.2
10,965
5,154
5,154
0.50
8.55
-0.69
0.58
250.7
11,652
5,654
10,809
1.00
9.29
0.00
1.07
251.2
12,359
6,003
16,811
1.50
€ 9.73
0.41
1.53
251.7
13,087
6,362
23,173
2.00
€ 10.05 €
0.69
1.99
252.2
13,835
6,731
29,903
2.50
10.31
0.92
2.45
252.7
14,603
7,110
37,013
3.00
€ 10.52 €
1.10
2.91
253.2
15,393
7,499
44,512
3.50
10.70
1.25
3.38
253.7
16,202
7,899
52,411
4.00
10.87
1.39
3.87
254.2
17,029
8,308
60,718
4.50
€ 11.01
1.50
4.36
254.7
17,871
8,725
69,443
5.00
11.15
1.61
4.86
255.2
18,726
9,149
78,593
5.50
11.27
1.70
5.38
255.7
19,596
9,581
88,173
6.00
€ 11.39 €
1.79
5.91
256.2
20,479
10,019
98,192
6.50
11.49
1.87
6.45
256.7
21,377
10,464
108,656
7.00
11.60
1.95
7.00
257.2
22,289
10,917
119,572
7.50
€ 11.69 €
2.01
7.57
257.7
23,215
11,376
130,948
8.00
11.78
2.08
8.15
258.2
24,155
11,843
142,791
8.50
€ 11.87 €
2.14
8.74
258.7
25,109
12,316
155,107
9.00
€ 11.95 €
2.20
9.35
259.2
26,078
12,797
167,904
9.50
12.03
2.25
9.98
Regression Output:
b= 1.23 (X Variable Coeff)
Ks- 9,961 (eY-i ter-pt)
Stage - Storage Equation is of the form: S = (Ks)(Z)b
printed: 1/28/2022 3:56 PM Page 1 of 3

Barrel
Number of Barrels =
Dia. of Barrel =
Area of Barrel, (Ab) _
Pipe Length, (L) _
Friction Coeff, (Kp) _
Inv. of Barrel =
Riser
Elev. of Riser Crest
Rectangular
Length Weir— 36 inches
Total Weir Length=
Area of Riser =
Orifice in Riser
Dia. of Orifice =
Number of Orifices =
Area of Orifice, (Ab) _
Orifice Coefficient (Cd) _
Inv. of Orifice =
Length of weir —
Top of weir —
Weir Coefficient (Cw)—
Width of Spillway (Approx.) _
Weir Coefficient =
Crest Elevation =
Maximum Release Rate, (Q100) _
Release Rate, (Q100) _
Normal Water Surface Elev. _
1
30 inches
4.91 sf
50 feet
0.00786
249.70 feet
257.80 feet
Width Weir— 48 inches
14.00 feet
12.00 sq. ft.
1.75 inches
1
0.02 sf
0.60
249.70 feet
0.30 feet
253.70 feet
3.00
15 feet
3.3
258.20 feet
7.63 cfs
7.62 cfs
249.70 feet
Water Surface Elev. @ Outlet (Qloo) = 257.77 feet
printed: 1/28/2022 3:56 PM
Page 2 of 3

Peak Inflow, (Qp) =>
Time to Peak Calculation: CN=
Q*=
vo1=
Time to Peak, (Tp) _>
(SCS TR-55)
49.48 cfs
84 P= 8.33 in.
6.41 in. (depth of runoff)
73,556 cf (vol. of runoff)
38.9 minutes
S= 1.90 in.
printed: 1/28/2022 3:56 PM
Page 3 of 3