SW6220201_Design Calculations (10yr Storm)_20220510

DESIGN REQUIREMENTS:
A. Pass the storm event
Drainage Area, (DA) = 18.38 acres
Intensity, (I) = 6.22 inches/hr
Composite Runoff Coefficient, (C) _> 0.30
Maximum Release Rate, (Q10) _> 34.30 cfs
Drainage Area, (DA) = 18.38 acres
Intensity, (I) = 7.78 inches/hr
Composite Runoff Coefficient, (C) _> 0.56
Peak Release Rate, (Q10) _> 80.08 cfs
Contour
Contour
Incr.
Accum.
Stage
Elev.
Area
Storage
Storage (S)
(Z)
00
(sfl
(cfl
(cfl
00
In (S)
In (Z)
Z est
265.5
16,163
-
-
-
266.0
17,919
8,521
8,521
0.50
9.05
-0.69
0.53
266.5
18,789
9,177
17,698
1.00
9.78
0.00
lAl
267.0
19,698
9,622
27,319
1.50
€ 10.22 €
0.41
1.50
267.5
20,623
10,080
37,400
2.00
€ 10.53
0.69
1.98
268.0
21,564
10,547
47,946
2.50
10.78
0.92
2.47
268.5
22,521
11,021
58,968
3.00
€ 10.98 €
1.10
2.98
269.0
23,494
11,504
70,471
3.50
11.16
1.25
3.49
269.5
24,483
11,994
82,466
4.00
11.32
1.39
4.02
270.0
25,485
12,492
94,958
4.50
€ 11.46 €
1.50
4.56
Regression Output:
b= 1.12 (X Variable Coeff)
Ks- 17,433 (eY-'ri`e"pt)
Stage - Storage Equation is of the form: S = (Ks)(Z)b
printed: 5/10/2022 6:12 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— 96 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
48 inches
12.57 sf
53 feet
0.00420
265.50 feet
269.00 feet
Width Weir— 48 inches
24.00 feet
32.00 sq. ft.
2.75 inches
1
0.04 sf
0.60
265.50 feet
0.00 feet
500.00 feet
3.00
30 feet
3.3
269.20 feet
34.30 cfs
80.07 cfs
265.50 feet
Water Surface Elev. @ Outlet (Qlo) = 269.69 feet
printed: 5/10/2022 6:12 PM
Page 2 of 3

Peak Inflow, (Qp) =>
Time to Peak Calculation: CN=
Q*=
vo1=
Time to Peak, (Tp) _>
(SCS TR-55)
80.08 cfs
87 P= 5.39 in.
3.94 in. (depth of runoff)
262,604 cf (vol. of runoff)
39.3 minutes
S= 1.49 in.
printed: 5/10/2022 6:12 PM
Page 3 of 3