SW6220401_Design Calculations_20220621 (9)

DESIGN REQUIREMENTS:
A. Post development discharge < or = Predevelopment discharge
Drainage Area, (DA) _
Intensity, (I) _
Composite Runoff Coefficient, (C) _>
Maximum Release Rate, (Q10) _>
Drainage Area, (DA) _
Intensity, (I) _
Composite Runoff Coefficient, (C) _>
Peak Release Rate, (Q10) _>
1.50 acres
7.54 inches/hr
0.30
3.39 cfs
r�
2.26 acres
7.54 inches/hr
0.78
13.29 cfs
Contour
Contour
Incr.
Accum.
Stage
Elev.
Area
Storage
Storage (S)
(Z)
00
(sf)
(cf)
(cf)
00
In (S)
In (Z)
Z est
321.0
16,000
-
-
321.0
5,046
11
11
0.00
2.35
-6.91
0.00
321.5
6,326
2,843
2,854
0.50
7.96
0.69
0.52
322.0
6,987
3,328
6,182
1.00
8.73
0.00
0.99
322.5
7,662
3,662
9,844
1.50
€ 9.19
0.41
1.47
323.0
8,352
4,004
13,848
2.00
9.54
0.69
1.96
323.5
9,055
4,352
18,199
2.50
€ 9.81
0.92
2.47
324.0
9,773
4,707
22,906
3.00
10.04
1.10
3.00
324.5
10,505
5,070
27,976
3.50
10.24
1.25
3.55
325.0
11,251
5,439
33,415
4.00
€ 10.42 €
1.39
4.12
Regression Output:
b= 1.18 (X Variable Coeff)
Ks- 6,255 (eY-i ter-pt)
Stage - Storage Equation is of the form: S = (Ks)(Z)b
printed: 6/21/2022 7:12 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
46 feet
0.00786
305.15 feet
323.65 feet
Width Weir— 48 inches
14.00 feet
12.00 sq. ft.
1.50 inches
1
0.01 sf
0.60
321.00 feet
0.55 feet
322.06 feet
3.00
15 feet
3.3
324.00 feet
3.39 cfs
3.33 cfs
321.00 feet
Water Surface Elev. @ Outlet (Qlo) = 323.63 feet
printed: 6/21/2022 7:12 AM
Page 2 of 3

Peak Inflow, (Qp) =>
Time to Peak Calculation: CN=
Q*=
vo1=
Time to Peak, (Tp) _>
(SCS TR-55)
13.29 cfs
82 P= 5.23 in.
3.29 in. (depth of runoff)
17,890 cf (vol. of runoff)
24.3 minutes
S= 2.20 in.
printed: 6/21/2022 7:12 AM
Page 3 of 3