SW6220101_Design Calculations (10-yr Storm)_20221013

DESIGN REQUIREMENTS:
A. Pass the storm event
Drainage Area, (DA) = 19.55 acres
Intensity, (I) = 3.80 inches/hr
Composite Runoff Coefficient, (C) _> 0.31
Maximum Release Rate, (Q10) _> 23.03 cfs
Drainage Area, (DA) = 19.55 acres
Intensity, (I) = 7.76 inches/hr
Composite Runoff Coefficient, (C) _> 0.61
Peak Release Rate, (Q10) _> 92.54 cfs
Contour
Contour
Incr.
Accum.
Stage
Elev.
Area
Storage
Storage (S)
(Z)
00
(sfl
(cfl
(cfl
00
In (S)
In (Z)
Z est
279.5
18,987
-
-
-
280.0
20,905
9,973
9,973
0.50
9.21
-0.69
0.55
280.5
21,893
10,700
20,673
1.00
9.94
0.00
1.04
281.0
22,901
11,199
31,871
1.50
€ 10.37 €
0.41
1.51
281.5
23,927
11,707
43,578
2.00
€ 10.68 €
0.69
1.98
282.0
24,972
12,225
55,803
2.50
10.93
0.92
2.46
282.5
26,034
12,752
68,554
3.00
€ 11.14 €
1.10
2.94
283.0
27,115
13,287
81,842
3.50
11.31
1.25
3.43
283.5
28,213
13,832
95,674
4.00
11.47
1.39
3.93
284.0
29,328
14,385
110,059
4.50
€ 11.61
1.50
4.44
284.5
30,460
14,947
125,006
5.00
11.74
1.61
4.96
285.0
31,607
15,517
140,523
5.50
11.85
1.70
5.49
285.5
32,770
16,094
156,617
6.00
€ 11.96 €
1.79
6.03
286.0
33,949
16,680
173,297
6.50
12.06
1.87
6.58
286.5
35,143
17,273
190,570
7.00
12.16
1.95
7.15
287.0
36,353
17,874
208,444
7.50
12.25
2.01
7.73
Regression Output:
b= 1.15 (X Variable Coeff)
Ks- 19,832 (eY-'ri`e"pt)
Stage - Storage Equation is of the form: S = (Ks)(Z)b
printed: 10/13/2022 10:48 AM 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, (Q10) _
Release Rate, (Q10) _
Normal Water Surface Elev. _
1
30 inches
4.91 sf
70 feet
0.00786
271.00 feet
285.00 feet
Width Weir— 48 inches
14.00 feet
12.00 sq. ft.
3.50 inches
1
0.07 sf
0.60
279.50 feet
1.00 feet
282.10 feet
3.00
25 feet
3.3
286.00 feet
23.03 cfs
45.14 cfs
279.50 feet
Water Surface Elev. @ Outlet (Qlo) = 285.65 feet
printed: 10/13/2022 10:48 AM
Page 2 of 3

Peak Inflow, (Qp) =>
Time to Peak Calculation: CN=
Q*=
vo1=
Time to Peak, (Tp) _>
(SCS TR-55)
92.54 cfs
83 P= 5.48 in.
3.61 in. (depth of runoff)
256,295 cf (vol. of runoff)
33.2 minutes
S= 2.05 in.
printed: 10/13/2022 10:48 AM
Page 3 of 3