SW3220305_Design Calculations (Swale)_20220510

SUBJECT: Swale Sizing
SYSTEM:
CLIENT: Water and Sewer Authority of Cabarrus County
PROJECT NAME: Rocky River Regional WA/TP Expansion Phase 3
PROJECT NUMBER: 156673
Calculations to size the stormwater pipes throughout the site
C Factors
I m pervious Area 0.95
Pervious Area -Grass 0.3
Pervious Area -Soil 0.6
Basin Areas and C Factors
DISCIPLINE: Civil
CREATED BY: Daniel Wright
CHECKED BY: Kim Devendorf
DATE: 5/5/22
CURRENT 0
REVISION:
STANDARD APPLICATION SOFTWARE USED
QC Checker Section Sign -Off: -
Software Name
REFERENCE
QC Checker Section Sign -Off: -
Document Name
CALCULATION BASIS AND ASSUMPTIONS
QC Checker Section Sign -Off: -
Swale #
Impervious
Area x
C Impery + Pervious area
x C' Pery
+ Total Area -
Composite'C'
1
0.00
0.95 2.30
0.3
2.30
0.30
2
0.05
0.95 1.55
0.3
1.61
0.32
3
0.03
0.95 0.03
0.3
0.06
0.64
4
0.08
0.95 0.42
0.3
0.50
0.40
5
0.11
0.95 0.35
0.3
0.46
0.46
6
0.35
0.95 0.74
0.3
1.09
0.51
7
0.49
0.95 1.14
0.3
1.63
0.49
TOC (min) 5.00 Assumed
Intensity (10-yr) (in/hr) 7.32
Swale Flow (Q=CIA)
Swale # Q (cfs)
1
5.06
2
3.77
3
0.27
4
1.48
5
1.55
6
4.04
7
5.89
Inlcudes Swale 6
Swale Dimensions
Note: b = 0 for triangular channels and z = 0 for rectangular channels.
n �1
z
b
NOTE: For figure of swale locations and contributing drainage areas, see '11_RRRWVVTP-Ditch-DA.pdf'

Swale 1 (EQ Tanks) Swale 2 (EQ Road North) Swale 3 (Maintenance CanoDV Ditch West)
Input
Input
Input
Flow Rate (Q) =
5.06 cfs
Flow Rate (Q) =
3.77 cfs
Flow Rate (Q) =
0.27 cfs
Manning's n (n)
0.035
Manning's n (n)
0.035
Manning's n (n)
0.035
Downstream Slope (S)
0.0075 ft/ft
Downstream Slope (S)
0.0150 ft/ft
Downstream Slope (S)
0.0700 ft/ft
Base Width (b)
0.0 ft
Base Width (b)
0.5 ft
Base Width (b)
0.0 ft
Side Slope (z)
2.00
Side Slope (z)
2.00
Side Slope (z)
2.00
Uniform Flow Depth
Uniform Flow Depth
Uniform Flow Depth
Flow Area (A) =
2.26 ftZ
Flow Area (A) =
1.39 ftZ
Flow Area (A) =
0.11 ftZ
Wetted Perim. (P) =
4.75 ft
Wetted Perim. (P) =
3.72 ft
Wetted Perim. (P) =
1.04 ft
Hydraulic Rad. (R) =
0.48 ft
Hydraulic Rad. (R) =
0.38 ft
Hydraulic Rad. (R) =
0.10 ft
Manning Convey. (K)'=
58.4 cfs
Manning Convey. (K)'=
30.8 cfs
Manning Convey. (K)'=
1.0 cfs
err1"=
0.0000 cfs
err1"=
0.0000 cfs
err1"=
0.0000 cfs
Unif. Flow Depth (y )=
1.06 ft
Unif. Flow Depth (y )=
0.72 ft
Unif. Flow Depth (y )=
0.23 ft
Critical Flow Depth
Critical Flow Depth
Critical Flow Depth
Flow Area (A) =
1.38 ftZ
Flow Area (A) =
1.10 ftZ
Flow Area (A) =
0.13 ftZ
Wetted Perim. (P) =
3.72 ft
Wetted Perim. (P) =
3.30 ft
Wetted Perim. (P) =
1.14 ft
Hydraulic Rad. (R) =
0.37 ft
Hydraulic Rad. (R) =
0.33 ft
Hydraulic Rad. (R) =
0.11 ft
Top Width (T) =
3.33 ft
Top Width (T) =
3.01 ft
Top Width (T) =
1.02 ft
err2"` =
0.0000 ft,
err2"' =
0.0000 ft,
err2"` =
0.0000 ft,
Crit. Flow Depth (y.)=
0.83 ft
Crit. Flow Depth (y,)=
0.63 ft
Crit. Flow Depth (yc)=
0.26 ft
Velocity
lVelocity
lVelocity
Velocity (V)
2.24 fps
lVelocity (V)
2.70 fps
I Velocity (V)
2.48 fps
Swale 4 (Maintenance Canonv East) Swale 5 (TSPS No. 2) Swale 6 (Box 2A and AB No. 6)
Input
Input
Input
Flow Rate (Q) =
1.48 cfs
Flow Rate (Q) =
1.55 cfs
Flow Rate (Q) =
4.04 cfs
Manning's n (n)
0.035
Manning's n (n)
0.035
Manning's n (n)
0.035
Downstream Slope (S)
0.0850 ft/ft
Downstream Slope (S)
0.0200 ft/ft
Downstream Slope (S)
0.0100 ft/ft
Base Width (b)
0.0 ft
Base Width (b)
0.0 ft
Base Width (b)
0.0 ft
Side Slope (z)
2.00
Side Slope (z)
2.00
Side Slope (z)
2.00
Uniform Flow Depth
Uniform Flow Depth
Uniform Flow Depth
Flow Area (A) =
0.36 ftZ
Flow Area (A) =
0.64 ftZ
Flow Area (A) =
1.71 ftZ
Wetted Perim. (P) =
1.90 ft
Wetted Perim. (P) =
2.54 ft
Wetted Perim. (P) =
4.14 ft
Hydraulic Rad. (R) =
0.19 ft
Hydraulic Rad. (R) =
0.25 ft
Hydraulic Rad. (R) =
0.41 ft
Manning Convey. (K)'=
5.1 cfs
Manning Convey. (K)'=
10.9 cfs
Manning Convey. (K)'=
40.4 cfs
err1"=
0.0000 cfs
err1"=
0.0000 cfs
err1"=
0.0000 cfs
Unif. Flow Depth (y )=
0.43 ft
Unif. Flow Depth (y )=
0.57 ft
Unif. Flow Depth (y )=
0.93 ft
Critical Flow Depth
Critical Flow Depth
Critical Flow Depth
Flow Area (A) =
0.52 ftZ
Flow Area (A) =
0.54 ftZ
Flow Area (A) =
1.15 ftZ
Wetted Perim. (P) =
2.28 ft
Wetted Perim. (P) =
2.31 ft
Wetted Perim. (P) =
3.40 ft
Hydraulic Rad. (R) =
0.23 ft
Hydraulic Rad. (R) =
0.23 ft
Hydraulic Rad. (R) =
0.34 ft
Top Width (T) =
2.04 ft
Top Width (T) =
2.07 ft
Top Width (T) =
3.04 ft
err2"'=
0.0000 ft,
err2"'=
0.0000 ft,
err2"'=
0.0000 ft,
Crit. Flow Depth (yc)=
0.51 ft
Crit. Flow Depth (yc)=
0.52 ft
Crit. Flow Depth (yc)=
0.76 ft
Velocity
lVelocity
lVelocity
Velocity (V)
4.10 fps
lVelocity (V)
2.41 fps
lVelocity (V)
2.36 fps
Swale 7 (Blower Buildina. includes Swale 6)
Input
Flow Rate (Q) =
5.89 cfs
Manning's n (n)
0.035
Downstream Slope (S)
0.0100 ft/ft
Base Width (b)
0.0 ft
Side Slope (z)
2.00
Uniform Flow Depth
Flow Area (A) =
2.27 ftZ
Wetted Perim. (P) =
4.77 ft
Hydraulic Rad. (R) =
0.48 ft
Manning Convey. (K)'=
58.9 cfs
err1"=
0.0000 cfs
Unif. Flow Depth (y )=
1.07 ft
Critical Flow Depth
Flow Area (A) =
1.56 ftZ
Wetted Perim. (P) =
3.95 ft
Hydraulic Rad. (R) =
0.40 ft
Top Width (T) =
3.54 ft
err2"'=
0.0000 ft,
Crit. Flow Depth (yc)=
0.88 ft
Velocity
Velocity (V)
2.59 fps
*Manning's conveyance equals (1.486/n)AR2/3
-Manning's Q - Given Q
"'Q2/g - A3/T