SW3220305_Design Calculations (Pipes)_20220510

Brown A ,- Caldwell
SUBJECT: Stormwater Network Sizing
SYSTEM:
CLIENT: Water and Sewer Authority of Cabarrus County
PROJECT NAME: Rocky River Regional Wastewater Treatment Plant Expansion
PROJECT NUMBER: 156673
pes
C Factors
Impervious 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
REVISION: 0
Impervious
Composite
Basin #
Area x
C Impery
+ Pervious area
x C' Pery
+ Total Area =
'C'
ENDWALL 1
0.08
0.95
3.81
0.3
3.89
0.31
STD 1 - DI
0.036
0.95
0.37
0.3
0.41
0.36
STD 4 - DI
0.13
0.95
0.46
0.3
0.59
0.44
TRENCH DRAIN
0.21
0.95
0.78
0.3
0.99
0.44
EXIST DI
0.11
0.95
0.35
0.3
0.46
0.46
TOC (min) 5.00
Intensity (10-yr) (in/hr) 7.32
Basin Flow Q=CIA
asin
c s
ENDWALL 1
8.92
STD 1 - DI
1.07
STD 4 - DI
1.92
TRENCH DRAIN
3.18
EXIST DI
1.55
Assumed
0.46 8/3 1/2 tannings equation for pipe flow flowing full
Q = n (D) s
D = Qn1 3/8 Mannings Equation solved for diameter
0.46s 1/2
See attached figure for drains a basin and i e labels. Pi es with a second basin indicate it conve s flow from two drainage
ipe
asin
asin
c s
s %
D ft
Din
use in
PIPE - 1
ENDWALL - 1
N/A
8.92
0.50
1.51
18.16
30
PIPE - 2
STD 1 - DI
N/A
1.07
0.50
0.68
8.20
15
PIPE - 3
ENDWALL - 1
STD 1 -DI
9.99
0.50
1.58
18.95
24
PIPE - 4*
STD 4 - DI
TRENCH D
5.10
0.50
1.23
14.72
24
Exi
PIPE - 5
STD 4 -DI
N/A
1.92
6" width
Se(
PIPE - 6
TRENCH D
N/A
3.18
1.74
0.81
9.76
12
PIPE - 7*
EXIST DI
N/A
1.55
1.74
0.62
7.45
12
Exi
n 0.011
Concrete Manninas n
*Existing pipe
basins
st 24" Pipe
conclusion note
st 12" Pipe
Provided diameters are all larger than the required diameter that was calculated. The trench drain dimension is sized at a 6" width due to suppliers
recommending 6" wide drains for flows up to 4 cfs and the actual flow is 3.18 cfs.
5/10/2022 Page 1 of 1
9:01 AM 8x11 Portrait Calculation STRM-Pipe-Sizing

Brown AND Caldwell
SUBJECT: Stormwater Network Sizing
SYSTEM: 0
CLIENT: Water and Sewer Authority of Cabarrus County
PROJECT
NAME: Rocky River Regional Wastewater Treatment Plant Expansion
PROJECT
NUMBER: 156673
Drainage Area Map
DISCIPLINE: Civil
CREATED BY: Daniel Wright
CHECKED BY: Dave Varjabedian
DATE: 01 /10/22
CURRENT
REVISION: 0
5/5/2022 Page 7 of 7
3:53 PM 8x11 Portrait Data -Ref STRM-Pipe-Sizing

NOAA Atlas 14, Volume 2, Version 3�,
Location name: Concord, North Carolina, USA*
Latitude: 35.32640, Longitude:-80.542° er`N
Elevation: 563.03 ft**
' source: ESRI Maps k,N I—
" source: USGS
POINT PRECIPITATION FREQUENCY ESTIMATES
G.M. Bonnin, D. Martin, B. Lin, T. Parcybok, M.Yekta, and D. Riley
NOAA, National Weather Service, Silver Spring, Maryland
PF tabular I PF graphical I Maps & aerials
PF tabular
PDS-based point precipitation frequency estimates with 90% confidence intervals (in inches/hour)1
Average
recurrence interval (years)
1 2 5
10
25 50 100 200 500 1000
4.85 5.72 6.66
7.32
8.06 8.57 9.02 9.42 9.84 10.1
5-min
(4.46-5.26) (5.28-6.23) (6.13-7.24)
(6.72-7.93)
(7.37-8.72) 1 (7.79-9.28) 1 (8.16-9.77) 1 (8.47-10.2) 1 (8.78-10.7) 1 (8.98-11.0)
10-min
3.87
(3.57-4.20)
4.58
(4.22-4.98)
5.33
(4.91-5.80)
5.86
(5.37-6.35)
6.43
(5.87-6.95)1
6.82
(6.20-7.39)
7.17
1 (6.49-7.76)
7.46
1 (6.72-8.08)
7.79
1 (6.95-8.45)
7.99
1 (7.07-8.67)
15-min
2 98�3.50
3.54 4417
4. 4 4089
4. 3 5435
4.96 5388
5. 476.23
5.47 6454
5.65-6.80
5. 3---7309
5.91-67826
2.21
2.65
3.20
3.58
4.02
4.34
4.63
4.89
5.20
5.41
30-min
2
(2.44-2.88)
(2.94-3.47)
(3.28-3.88)
(3.67-4.35)
(3.94-4.69)
(4.19-5.01)
(4.40-5.29)
(4.64-5.64)
(4.79-5.88)
1.38
1.66
2.05
2.33
2.68
2.94
3.19
3.43
3.73
3.95
60-min
(1.27-1.50) 11
(1.53-1.81) 11
(1.88-2.23) 1(2.14-2.52)1
(2.45-2.90)
1 (2.67-3.18)
1 (2.88-3.45)
1 (3.09-3.71)
1 (3.33-4.05)
1 (3.50-4.29)
0.796
0.964
1.20
1.37
1.60
1.76
1.93
2.09
2.30
2.46
2-hr
(0.730-0.870)
(0.883-1.06)
(1.09-1.31) 1(1.25-1.49)1
(1.45-1.74)
1 (1.59-1.92)
1 (1.73-2.10)
1 (1.86-2.28)
1 (2.03-2.51)
1 (2.15-2.69)
0.567
0.685
0.854
0.984
1.16
1.29
1.43
1.57
1.75
1.90
3-hr
(0.520-0.621)
(0.628-0.751)
(0.782-0.936)
(0.898-1.07)
(1.05-1.26)
1 (1.17-1.41)
1 (1.28-1.55)
1 (1.39-1.71)
1 (1.54-1.91)
1 (1.65-2.07)
0.344
0.415
0.518
0.598
0.706
0.791
0.878
0.967
1.09
1.18
6-hr
(0.315-0.377)
(0.381-0.454)
(0.474-0.566)
(0.546-0.653)
(0.640-0.768)
(0.713-0.860)
(0.785-0.955)
(0.856-1.05)
(0.951-1.18)
(1.02-1.29)
0.203
0.245
0.307
0.357
0.424
0.479
0.535
0.593
0.674
0.739
12-hr
(0.187-0.221)
(0.225-0.268)
(0.282-0.336)
(0.326-0.390)
(0.385-0.461)
(0.431-0.519)
(0.477-0.579)
(0.523-0.641)
(0.585-0.728)
(0.632-0.799)
0.121
0.145
0.183
0.212
0.251
0.283
0.315
0.349
0.395
0.431
24-hr
(0.112-0.130)
(0.135-0.157)
(0.170-0.197)
(0.196-0.228)
(0.233-0.271)
(0.261-0.305)
(0.290-0.340)
(0.320-0.376)
(0.360-0.426)
(0.392-0.466)
0.071
0.085
0.106
0.123
0.145
0.163
0.181
0.200
0.226
0.246
2-day
(0.066-0.076)
(0.079-0.092)
(0.099-0.114)
(0.114-0.132)
(0.134-0.156)
(0.150-0.175)
(0.167-0.194)
(0.183-0.215)
(0.206-0.243)
(0.224-0.265)
0.050
0.060
0.075
0.086
0.101
0.114
0.126
0.139
0.157
0.171
3-day
(0.046-0.054)
(0.056-0.064)
(0.069-0.080)
(0.080-0.092)
(0.094-0.109)
(0.105-0.122)
(0.116-0.135)
(0.128-0.149)
(0.144-0.169)
(0.156-0.184)
0.040
0.048
0.059
0.067
0.080
0.089
0.099
0.109
0.123
0.134
4-day
(0.037-0.042)
(0.044-0.051)
(0.055-0.063)
(0.063-0.072)
(0.074-0.085)
(0.082-0.095)
(0.091-0.106)
(0.100-0.117)
(0.112-0.132)
(0.122-0.144)
0.026
0.031
0.038
0.043
0.051
0.057
0.063
0.069
0.077
0.084
7-day
(0.024-0.028)
(0.029-0.033)
(0.036-0.040)
(0.041-0.046)
(0.047-0.054)
(0.053-0.060)
(0.058-0.067)
(0.064-0.074)
(0.071-0.083)
(0.077-0.090)
0.021
0.025
0.030
0.034
0.039
0.043
0.048
0.052
0.058
0.062
10-day
(0.020-0.022)
(0.023-0.026)
(0.028-0.032)
(0.032-0.036)
(0.037-0.042)
(0.040-0.046)
(0.044-0.051)
(0.048-0.055)
(0.053-0.062)
(0.057-0.066)
0.014
0.017
0.020
0.022
0.025
0.028
0.030
0.033
0.036
0.039
20-day
(0.013-0.015)
(0.016-0.017)
(0.018-0.021)
(0.021-0.023)
(0.024-0.026)
(0.026-0.029)
(0.028-0.032)
(0.031-0.034)
(0.034-0.038)
(0.036-0.041)
30-day
0.01100.012
0.013-0 014
0.015-0 016
0.016-0 018
0.019-0 021
0.020-0.022
0.02 -0 024
0.023-0 026
0.025-0 029
0.027--0 030
0.010
0.011
0.013
0.014
0.016
0.017
0.018
0.019
0.021
0.022
45-day
(0.009-0.010)
(0.011-0.012)
(0.012-0.013)
(0.013-0.015)
(0.015-0.016)
(0.016-0.018)
(0.017-0.019)
(0.018-0.020)
(0.020-0.022)
(0.021-0.023)
0.009
0.010
0.011
0.012
0.014
0.015
0.016
0.017
0.018
0.019
60-day
(0.008-0.009)
(0.010-0.010)
(0.011-0.012)
(0.012-0.013)
(0.013-0.014)
(0.014-0.015)
(0.015-0.016)
(0.016-0.017)
(0.017-0.019)
(0.018-0.020)
Precipitation frequency (PF) estimates in this table are based on frequency analysis of partial duration series (PDS).
Numbers in parenthesis are PF estimates at lower and upper bounds of the 90% confidence interval. The probability that precipitation frequency estimates (for a
given duration and average recurrence interval) will be greater than the upper bound (or less than the lower bound) is 5%. Estimates at upper bounds are not
checked against probable maximum precipitation (PMP) estimates and may be higher than currently valid PMP values.
Please refer to NOAA Atlas 14 document for more information.
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PF graphical

PD5-based intensity -duration -frequency (IDF) curves
Latitude-- 35.3264'. Longitude--S4.5420"
11*16NSI61*1
e
° 0.100
•L
CL
a 0-010
0 001
N A tb �y �{
LA O L' A O rl C'V f1�1 q rx O O O Ln O
H rn �n � N rn IT�c
Duration
100.000
10.000
L
k
41
c
1.000
G�
° 0.100
L
49
a 0.010
0.0011 i i i i i i
1 2 5 10 25 50 100 200 500 1000
Average recurrence interval (years)
NOAA Atlas 14, Volume 2, Version 3 Created (GMT): Wed Oct 27 17:48:36 2021
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Maps & aerials
Small scale terrain
Average recurrence
interval
{years}
— 1
2
— 5
— 14
— 25
50
100
200
500
1000
Duration
— "in —
2-day
— 10-min —
3-day
15-min —
"By
— 30-min —
7-day
— 60-min —
10-day
— 2-fir —
20-day
— 3-hr —
30-day
— "r —
45-day
— 12-hr —
50-day
— 24-hr

Large scale terrain
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�i
III city 0
,;h Y�+Inston-Sal@Ill
* . [furham
Greensboro •
� Ralei
4 is hAt h�litchell
Asheville NORTIJ CAROL INA
i Arlotte '
Fayetteville.
'Greenville` +
lookm LAROLINA Wile
mi
Large scale map
Jslyort �wi
Johnson � .
Greensboro
'? Q rh grrt
Avhevllle. North
e Carolina
,-` Fajrei
le
a
100km
mi mbia Large scale aerial

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US Department of Commerce
National Oceanic and Atmospheric Administration
National Weather Service
National Water Center
1325 East West Highway
Silver Spring, MD 20910
Questions?: [e-mail]
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