SW3210801_Stormwater Report_20220128

ffi %i ti ti 14 l I'l 1111 o f{ f f
p R04l�f'�/ice
S J+
SEAL
48704 —
1--Z(,--ZZ
ff{'�'►�+�rllnsx t ti►*.
IIIljj1 jjj/jI
? THOMAS
8 HUTTON -
__ ENGINEERING
CO
`� •• No F-0871 �•v�
tk
••,•i�i ir4 ......•HaQ�ti`%
l I111f1 �►�0%
Iq
PRELIMINARY
STORMWATER MANAGEMENT REPORT
FOR:
PROJECT: 1-85 COMMERCE CENTER
ROWAN COUNTY, NC
PREPARED FOR:
NORTHPOINT DEVELOPMENT
4805 MONTGOMERY RD., SUITE 310
CINCINNATI, OHIO 45212
T&H PROJECT # 29101.0000
DATE: JANUARY 2022
Prepared by:
THOMAS Sc HUTTON
www.thomasandhutton.com

STORMWATER MANAGEMENT REPORT
1-85 Commerce Center
Project: 1-85 Commerce Center
T&H Job Number: J-29101.0000
Location: 410 Webb Road, Salisbury, NC (Rowan County)
Date Prepared: January 2022
Owner:
Northpoint Development
Address:
4805 Montgomery Road, Suite 310
Cincinnati, Ohio 45212
Contact:
Michael Johnston
Phone:
[phone]
Engineer: Thomas & Hutton Engineering Co.
Address: 1020 Euclid Avenue, Charlotte, NC 28203
Contact: Brad Smith, PE, PMP
Phone: [phone]
Report Prepared By:
William Bradley S , PE, PMP
Nestor Hernandez
Report Reviewed By:
William Bradley Smith, PE, PMP
H THOMAS & HUTTON
Date: )--ZCo--ZZ
Date: I—ZCo—ZZ
PAGE i

1-85 COMMERCE CENTER PRELMINARY STORMWATER MANAGEMENT REPORT
TABLE OF CONTENTS
Section 1
-Summary of Results.......................................................................................................
Page 1
Section 2 - Project Narrative...........................................................................................................Page
2
Section3
- Purpose...........................................................................................................................
Page 2
Section 4-
Proposed Drainage System.........................................................................................Page
3
Section 5
- Stormwater Quantity Methodology............................................................................
Page 4
Section6
- Hydrology.......................................................................................................................
Page 6
Section 7
- Runoff Calculations......................................................................................................Page
5
Section 8 - Pre -Development Conditions.....................................................................................
Page 6
Section 9
- Post -Development Conditions....................................................................................Page
6
Page ii

1-85 COMMERCE CENTER PRELMINARY STORMWATER MANAGEMENT REPORT
APPENDICES
ProjectMapping...................................................................................................................... Appendix A
LocationMap.................................................................................................................. Exhibit A.1
FEMAMap....................................................................................................................... Exhibit A.2
SoilsMap.......................................................................................................................... Exhibit A.3
Pre -Development Drainage Map and SSA Network Diagram ...........................................Appendix B
Pre -Development Conditions Drainage Calculations......................................................... Appendix C
Post -Development Drainage Map and SSA Network Diagram ......................................... Appendix D
Post -Development Conditions Drainage Calculations........................................................Appendix E
Water Quality Calculations...................................................................................................... Appendix F
Time vs. Stage (Drawdown Time)...........................................................................................Appendix G
Erosion Control Calculations...................................................................................................Appendix H
Stormwater Piping and Inlet Design Calculations................................................................ Appendix I
Page iii

1-85 COMMERCE CENTER PRELMINARY STORMWATER MANAGEMENT REPORT
SECTION 1 - SUMMARY OF RESULTS
Post -development peak flow is less than pre -development peak flow for the 2-year and 25-year,
24 hour storm events. All four wet ponds are interconnected to act as one dynamic system as
the water elevation rises and falls. The wet ponds provide the required Water Quality Storage
Volume. Water Quality Storage Volume does not include the forebay areas. The stormwater
modeling and design is governed by both Rowan County Ordinances and NCDEQ stormwater
design requirements and the design of the ponds meets the stormwater quality and quantity
requirements of these two agencies.
A summary of the modeling results are provided below:
TABLE 1
Summary of Results - Peak Runoff (Site Only)
Condition
Site Peak Runoff (cfs)
2-yr
10-yr
25-yr
50-yr
100-yr
PRE -development
22.4 cfs
48.3 cfs
64.0 cfs
73.3 cfs
86.3 cfs
POST -development
13.2 cfs
35.9 cfs
50.2 cfs
73.0 cfs
135.1 cfs
TABLE 2
Summary of Results - Peak Pond Stages
Pond #
NWL
(ft)
TOB
(ft)
Peak Pond Stage (ft)
for Storm Events
2-yr
10-yr
25-yr
50-yr
100-yr
Pond # 1
764.0'
770.0'
766.7'
767.9'
768.5'
768.8'
769.0'
Pond #2
764.0'
770.0'
766.7'
767.9'
768.5'
768.8'
769.0'
Pond #3
764.0'
770.0'
766.7'
768.0'
768.6'
768.9'
769.0'
Pond #4
764.0'
770.0'
766.7'
768.0'
768.6'
768.9'
769.0'
Note: Recovery or Bleed Down time is the time it takes for the detention basin to return to within
1-2 inches of its initial stage.
HPAGE 1
THOMAS & HUTTON

1-85 COMMERCE CENTER PRELMINARY STORMWATER MANAGEMENT REPORT
SECTION 2 - PROJECT NARRATIVE
The 1-85 Commerce Park project is a ±41.87 acre tract located at 410 Webb Road (PID 409-022).
The project development includes a proposed 676,000 sf spec -building and associated drives,
parking areas, loading areas, and stormwater BMPs. The owner of the project is NorthPoint
Development. The site is located in Rowan County, near the city of Salisbury, North Carolina. The
site is within the jurisdictional authority of Rowan County. Specific requirements are noted below,
but do not include the entirety of the applicable requirements or regulations.
SECTION 3 - PURPOSE
To define the limits of the drainage basin or basins that contain this project.
To document that major drainage infrastructure such as road crossings, drainage
connectors, ponds, and outfalls are adequate for all existing, proposed, and future
development within the project site.
To document compliance with regulatory requirements of Rowan County and NCDEQ
(North Carolina Department of Environmental Quality) summarized as follows:
Rowan County Stormwater Requirements:
• Rowan County's Ordinance, Chaper 18 - Soil Erosion and Sedimentation
Ordinance
o Ch. 18, Section 24.c Sewershed Areas, Item (5), specifically for the Town
Creek District, "The peak stormwater runoff leaving any site for the two-
year/24-hour storm shall be no greater for post -development conditions
than pre -development conditions."
o Ch. 18, Section 25 Stormwater Outlet Protection. Refer to ordinance for
detailed requirements.
• The project site lies within Rowan County's Phase II stormwater area and is also
subject to compliance with applicable standards of the NCDEQ (North Carolina
Department of Environmental Quality).
Stormwater Design Requirements per NCDEQ:
• Water Quality shall be maintained by retaining the 1-inch treatmen volume from
the project site. The Water Quality drawdown time for the treatment volume shall
be greater than 48-hours and less than 120-hours.
• Post -Development Runoff must be less than the Pre -Development Runoff for the
25-year storm event.
• 1-foot of freeboard is required above the water stage elevation for the 100-year
storm event.
• A combination of dry and wet ponds may be used in the final stormwater system
design and will conform to NCDEQ requirements.
• Sediment shall be prevented from leaving the site during construction.
• The Pond outfall pipe(s) shall be sized to accommodate the flow and HGL for the
100-year storm event.
• Discharge velocity analysis shall be performed for the 10-year storm event and
the flow dissipated and dispersed to prevent erosion using approved methods.
PAGE 2
H THOMAS & HUTTON

1-85 COMMERCE CENTER
PRELMINARY STORMWATER MANAGEMENT REPORT
Watershed Information:
The project site flows into Town Creek to the east. Town Creek's Stream Index
number is # 12-1 15-3 and is Classification "C" per NCDENR's Water Supply
Watersheds online mapping system. See screenshot image below.
wcm R:Z
SECTION 4 - PROPOSED DRAINAGE SYSTEM
Stro InfomwtWn:
Stream Index
12-115-3
sueam Hama
Town Cr"k
De piton-
From worn to Cron
Crack
c4auincatw+-
C
Dose of Clan.
Aug6w 31, 1974
What don chit Clan
More i
mean,
River Bann:
Yadkin Pr*-Das
Iomtn
...
The components of the proposed system consist of the proposed building, on -site roads, swales,
inlets, stormwater pipe network, wet ponds, pond outfall structures, and associated systems.
Roads, drives, parking, and open areas shall provide positive drainage away from the building. A
piped drainage system will convey runoff from the developed site area to a series of wet ponds
with forebays, outfall structures, and emergency overflow weir systems.
H THOMAS & HUTTON PAGE 3

1-85 COMMERCE CENTER PRELMINARY STORMWATER MANAGEMENT REPORT
SECTION 5 - STORMWATER QUANTITY METHODOLOGY
The pre- and post -development conditions of the site were analyzed using the Storm and Sanitary
Analysis (SSA) program developed by Autodesk. The program is used to model rainfall and
stormwater runoff and to perform hydraulic routing through the storm drainage system (including
existing and proposed storage/detention features such as wetlands, ponds, and lakes).
SSA is an advanced, powerful, and comprehensive modeling package for analyzing and
designing drainage systems, stormwater sewers, and sanitary sewers. The software can
simultaneously model complex hydrology, hydraulics, and water quality. The SSA program is built
on the highly tested and widely utilized SWMM methodologies. For this application of the SSA
program, the hydrology was simulated using the NRCS (SCS) TR-55 methodology. The hydraulics
was simulated utilizing hydrodynamic routing. Hydrodynamic routing solves the complete St.
Venant equations throughout the drainage network and includes modeling of backwater effects,
flow reversal, surcharging, looped connections, pressure flow, tidal outfalls, and interconnected
ponds.
The SSA program graphical user interface (GUI) allows for the input of hydrologic data for each
drainage sub -basin. See the appendices for input variables including runoff curve number, rainfall
distribution pattern, hydrograph peaking factor, area of each drainage sub -basin, and time of
concentration. The SSA program generates runoff hydrographs for each sub -basin based on
these user -specified variables. Hydrographs are generated by SSA using the NRCS Unit
Hydrograph (TR-55) Method.
The model's hydraulic input data consists of a system of nodes and links. Nodes represent
locations where flows enter or exit the system, pipe or channel characteristics change, or where
stage/storage/time relationships are provided. Links represent traditional types of hydraulic
conveyance such as pipes, channels, control structures, weirs, etc. The sizes, inverts, lengths, and
Manning "n" values for all pipes connecting the ponds or lakes are input into the model. In addition
to pipe information, all pond, lake, and detention area stage -area information and the respective
control structure information is input into the model. The node and link conditions are analyzed
within the model for a given storm, and flow conditions are determined.
Hydrographs for each drainage area are merged within the SSA program, and the hydrologic
results are then combined with the hydraulic information to model the hydraulic interactions of
the entire drainage system. The results include pond area and discharge rates and stage/storage
information during the storm events.
The storm drainage infrastructure onsite was modelled using the Analyze Gravity Networks program
developed by Autodesk. This program utilizes the model rainfall and stormwater runoff through the
storm drainage infrastructure to provide hydraulic grade line calculations and profiles for analyzing
the proposed storm drain network.
H THOMAS & HUTTON PAGE 4

1-85 COMMERCE CENTER PRELMINARY STORMWATER MANAGEMENT REPORT
SECTION 6 - HYDROLOGY
■ SCS TR-55 Method was used.
The rainfall intensity used for each storm event was obtained from NOAA precipitation records
for the Rowan County area. The following design storms may be used for model simulations
or as may apply per regulations:
- 2-year, 24-hour Design Storm =
- 10-year, 24-hour Design Storm =
- 25-year, 24-hour Design Storm =
- 50-year, 24-hour Design Storm =
- 100-year, 24-hour Design Storm=
3.5 inches (Required modeling)
5.1 inches (Required for modeling pipes)
6.0 inches (Required modeling)
6.5 inches (optional modeling)
7.2 inches (Required modeling)
SCS Type II, 24 hour rainfall distribution was used. This distribution pattern is determined by
the Soil Conservation Service comparing regional rain -gage data.
Soils primarily present on site consist of the following:
- (CeB2) Cecil sandy loam, 2 to 8 percent slopes HSG B
- (MbB) Mecklenburg loam, 2 to 8 percent slopes HSG C
- (SeB) Sedgefield fine sandy loam, 1 to 6 percent slopes HSG C/D
- (WaA) Warne loam, 0 to 2 percent slopes HSG C/D
SECTION 7 - RUNOFF CALCULATIONS
Peak flow rates for the watersheds were calculated by the SSA Program for applicable design
storms. The pre- and post -development drainage basins are shown in appendices that follow this
report.
Curve Numbers
Curve numbers were generated according to procedures set forth in SCS Technical
Release 55. The composite curve numbers for each drainage basin were calculated using
soils information from the Soil Survey for the county of the project site per The United States
Department of Agriculture Soil Conservation Service. Curve numbers were weighted
based on the land use and soil group within each basin.
Time of Concentration
Times of concentration were calculated according to procedures set forth in SCS
technical Release (TR) 55. The travel times (Tt) for overland flow, shallow concentrated
flow, and channel flow are added together for the drainage basin to get the time of
concentration Tc.
Basin information for the area of interest was collected for use in the SSA models. Basins
were delineated using surveyed topographic information. Basins were drawn and the
longest flow paths were found. The times of concentration were calculated based on the
NRCS, three part travel time method documented in TR-55. The three equations used are
summarized below:
HPAGE 5
THOMAS & HUTTON

1-85 COMMERCE CENTER
PRELMINARY STORMWATER MANAGEMENT REPORT
Sheet Flow: (hr.)
_ 0.007(nL)a,a
t1-Pz 0.05XS
0.4
Shallow Concentrated Flow: (hr.)
L
_
tz 3600 X V
Channel Flow: (hr.)
L
_
t3 3600 X V
Time of Concentration: (hr.)
t, = t1 + tZ + t3
Symbol
Dimension
Units
n
Manning's n
--
L
Length of flow
ft
P2
2 yr event
rainfall
in
S
Slope
ft/ft
Symbol
Dimension
Units
L
Length of flow
ft
V*
Velocity
ft/s
*Based on TR-55 velocity -slope relationship
Symbol
Dimension
Units
L
Length of flow
ft
V*
Velocity
ft/s
*Assumed to be 2 ft/s
Appendices C and E with time of concentration information are attached.
SECTION 8 - PRE -DEVELOPMENT CONDITIONS
The total acreage of the drainage basins analyzed in the stormwater calculations is approximately
±40.5 acres. The pre -development conditions for the site consists of a combination of woods with
an understory of brush and open grass field.
Stormwater runoff on the site was delineated according to the existing drainage patterns found
at the site and upon the field topographic survey completed within the site. The watershed
delineation was conducted to provide a comparison for pre -development and post -
development flows. Outfall "01" discharges eastward to Town Creek,w which flows northward.
(See Pre -Development Drainage Map - Appendix B).
SECTION 9 - POST -DEVELOPMENT CONDITIONS
The post -development drainage basins are shown on the Post -Development conditions
watershed map located in Appendix D of this report. The total post -development watershed area
analyzed for this project is approximately ±40 acres.
The post -development site will consist of an approximately ±676,000 sf spec -building and
associated private drives/roads, parking areas, truck loading areas, and four (4) new wet ponds.
Stormwater runoff from the site will be conveyed to the new wet ponds for water quality and
quantity purposes. The flow will be released through a series of orifices and weirs for the wet
ponds' outlet control structures. The proposed wet ponds are designed to meet criteria per Rowan
County and NCDEQ. Additionally, the required minimum freeboard of 1-foot has been provided
H THOMAS & HUTTON PAGE 6

1-85 COMMERCE CENTER PRELMINARY STORMWATER MANAGEMENT REPORT
beneath the top of the pond embankments for the 100-year storm event. Table 2 above depicts
the maximum water surface elevations for the 2-year, 10-year, 25-year, 50-year, and 100-year 24-
hour storm events for the ponds.
Stormwater conveyance (storm pipes, etc.) and inlet structures will be modeled and sized for the
10-year storm event using AutoDesk Civil 3D's "Analyze Gravity Network" program using the HEC-
22 method. The stormwater conveyance calculations are not provided for this preliminary
stormwater report.
Post -development peak flows are less than pre -development peak flows as required by Rowan
County for the 2-year, 24 hour storm event and for the 25-year storm, 24-hour storm event per
NCDEQ. See Appendices C and E for pre -development and post -development calculation results
from the SSA software modeling. Also, refer to the Summary of Results (Pre -Development vs. Post -
Development Conditions) at the beginning of this report in Table 1.
The Water Quality Calculations are provided in Appendix F. The Water Quality Calculations are
performed using a spreadsheet to determine the 1-inch water quality treatment volume (WQv),
which is calculated to be WQv = 104,471 cubic feet based on NCDEQ guidelines.
The Time vs. Stage drawdown plot from the SSA software model is provided in Appendix G to depict
the release rate of the 1 " treatment volume over time. The drawdown time is shown to be
approximately 50 hours, which is between the required timeframe of 48 to 120 hours. This is
performed in the model by setting the pond stage to the 1 " water quality volume elevation and
letting the pond drain through the pond outlet control structure.
H THOMAS & HUTTON PAGE

STORMWATER MANAGEMENT REPORT
1-85 COMMERCE CENTER
APPENDIX A
PROJECT MAPPING
Fj THOMAS & HUTTON

National Flood Hazard Layer FI RMette
8092'39"W 359626"N
r
•. Mr # %
IdrAt
raw
s-
+ ,
110554700J
: ff.'6/16/20WO k _ _ J16
FEMA
Legend
SEE FIS REPORT FOR DETAILED LEGEND AND INDEX MAP FOR FIRM PANEL LAYOUT
Without Base Flood Elevation (BFE)
Zone A, V, A99
SPECIAL FLOOD
With BFE or Depth ZoneAE, AD, AH, Ve, Aa
•
HAZARD AREAS
Regulatory Floodway
f �
s-t
0.2% Annual Chance Flood Hazard, Areas
of 1% annual chance flood with average
depth less than one foot or with drainage
areas of less than one square mile Zonex
Future Conditions 1% Annual
4 '- Chance Flood Hazard Zonex
" Area with Reduced Flood Risk due to
OTHER AREAS OF
Levee. See Notes. Zone
FLOOD HAZARD
Area with Flood Risk due to Leveezone D
NO SCREEN Area of Minimal Flood Hazard
+
Q Effective LOMRs
OTHER AREAS
Area of Undetermined Flood Hazard
•
GENERAL
- — - - Channel, Culvert, or Storm Sewer
STRUCTURES
i i i i i i i Levee, Dike, or Floodwall
zo.z Cross Sections with 1% Annual Chance
4.
77.5 Water Surface Elevation
- - - Coastal Transect
—sf3^•^•« Base Flood Elevation Line (BFE)
{
Limit of Study
Jurisdiction Boundary
— --- Coastal Transect Baseline
74 _
OTHER
_ Profile Baseline
FEATURES
Hydrographic Feature
Of72lE
i•� *'{?Q
i
10
LET
�y
y A
Feet 1.61000 8092'1"W 359557"N
0 250 500 1,000 1,500 2,000
Basemap: USGS National Map: Orthoimagery: Data refreshed October, 2020
❑ Digital Data Available
0 No Digital Data Available
AN
MAP PANELS ® Unmapped
PA
The pin displayed on the map is an
approximate
point selected by the user and does not represent
an authoritative property location.
This map complies with FEMA's standards for the use of
digital flood maps if it is not void as described below.
The basemap shown complies with FEMA's basemap
accuracy standards
The flood hazard information is derived directly from the
authoritative NFHL web services provided by FEMA. This map
was exported on 4/13/2021 at 4:14 PM and does not
reflect changes or amendments subsequent to this date and
time. The NFHL and effective information may change or
become superseded by new data overtime.
This map image is void if the one or more of the following map
elements do not appear: basemap imagery, flood zone labels,
legend, scale bar, map creation date, community identifiers,
FIRM panel number, and FIRM effective date. Map images for
unmapped and unmodernized areas cannot be used for
regulatory purposes.

541450
35o 36' 15" N
x
35o 35' 59" N
541450 541530 541610 541690 541770 541850
Map Scale: 1:3,550 if printed on A landscape (11" x 8.5") sheet.
Meters
$ N 0 50 100 200 300
Feet
0 150 300 E00 900
Map projection: Web Mercator Conermordinates: WGS84 Edge tics: UTM Zone 17N WGS84
USDA Natural Resources Web Soil Survey
Conservation Service National Cooperative Soil Survey
Hydrologic Soil Group —Rowan County, North Carolina
(SITE)
541530 541610 541690 541770 541850 541930
542010 542090
541930 542010 542090
542170
35o 36' 15" N
35o 35' 59" N
542170
4/13/2021
Page 1 of 3

Hydrologic Soil Group —Rowan County, North Carolina
(SITE)
MAP LEGEND
Area of Interest (AOI)
0
Area of Interest (AOI)
Soils
Soil Rating
Polygons
0
A
0
A/D
0
B
0
B/D
C
0
C/D
0
D
0
Not rated or not available
Soil Rating
Lines
r 0
A
r 0
A/D
B
B/D
N 0
C
r 0
C/D
r 0
D
r 0
Not rated or not available
Soil Rating
Points
0
A
0
A/D
0
B
0
B/D
❑ C
0 C/D
0 D
❑ Not rated or not available
Water Features
Streams and Canals
Transportation
— Rails
­0 Interstate Highways
US Routes
Major Roads
Local Roads
Background
D6 Aerial Photography
MAP INFORMATION
The soil surveys that comprise your AOI were mapped at
1:24,000.
Warning: Soil Map may not be valid at this scale.
Enlargement of maps beyond the scale of mapping can cause
misunderstanding of the detail of mapping and accuracy of soil
line placement. The maps do not show the small areas of
contrasting soils that could have been shown at a more detailed
scale.
Please rely on the bar scale on each map sheet for map
measurements.
Source of Map: Natural Resources Conservation Service
Web Soil Survey URL:
Coordinate System: Web Mercator (EPSG:3857)
Maps from the Web Soil Survey are based on the Web Mercator
projection, which preserves direction and shape but distorts
distance and area. A projection that preserves area, such as the
Albers equal-area conic projection, should be used if more
accurate calculations of distance or area are required.
This product is generated from the USDA-NRCS certified data as
of the version date(s) listed below.
Soil Survey Area: Rowan County, North Carolina
Survey Area Data: Version 17, Jun 3, 2020
Soil map units are labeled (as space allows) for map scales
1:50,000 or larger.
Date(s) aerial images were photographed: Oct 28, 2018—Oct
30, 2018
The orthophoto or other base map on which the soil lines were
compiled and digitized probably differs from the background
imagery displayed on these maps. As a result, some minor
shifting of map unit boundaries may be evident.
usoA Natural Resources Web Soil Survey 4/13/2021
Conservation Service National Cooperative Soil Survey Page 2 of 3

Hydrologic Soil Group —Rowan County, North Carolina
�yrra
Hydrologic Soil Group
Map unit symbol
Map unit name
Rating
Acres in AOI
Percent of AOI
CeB2
Cecil sandy clay loam, 2
B
8.6
20.6%
to 8 percent slopes,
moderately eroded
CfB
Cecil -Urban land
B
0.4
0.9%
complex, 2 to 8
percent slopes
ChA
Chewacla loam, 0 to 2
B/D
0.1
0.2%
percent slopes,
frequently flooded
LdB2
Lloyd clay loam, 2 to 8
B
0.0
0.0%
percent slopes,
moderately eroded
MbB
Mecklenburg loam, 2 to
C
15.1
36.0%
8 percent slopes
SeB
Sedgefield fine sandy
C/D
9.3
22.3%
loam, 1 to 6 percent
slopes
Ud
Udorthents, loamy
C
0.8
2.0%
WaA
Warne loam, 0 to 2
C/D
7.5
17.9%
percent slopes,
occasionally flooded
Totals for Area of Interest
41.9
100.0%
Rating Options
Aggregation Method: Dominant Condition
Component Percent Cutoff.- None Specified
Tie -break Rule: Higher
USDA Natural Resources Web Soil Survey 4/13/2021
am Conservation Service National Cooperative Soil Survey Page 3 of 3

STORMWATER MANAGEMENT REPORT
1-85 COMMERCE CENTER
APPENDIX B
PRE -DEVELOPMENT
DRAINAGE EXHIBIT
Fq THOMAS & HUTTON

/
/
fr
EGi806.0-
AEG -803.3 ��
71
�S fly EG 784.7 j s� �ti f •A$w °<, o e ��7ao� " `� «�
100 LF OF"l
tia
SHEET FLOW = ; (w ��� �l}�1��t1S� �Q L 1 �✓ ��5'� l BASIN 1
/ S y"7 ° 41.87 ACRES
2.11% sr p 438 LF OF f� ?�St *ter sr ✓,/ ;' { �z f \
r r SHEET
4. 8% f r CN: 72.39
��/� i� �� `(� �r % TOC: 96.38 MIN.
4-7
-1 Zt
o'o I��� 11( { I��L (_ :a x, �i i. qr N 4 1/�/ ✓/fir
/ y �� �(� \ C i�r `��� 7 �rf �• of •vim r° ��° i. r- rt
00I � /��•- r^ �, ;i, �:-: �' JJ l l) f � ..I �ti�\ •��-� i t,�' a4 .� � { � � ,,� _-,;w 1 J � .�6s f� Y /
790
LO
! � /• ' l { �� � f �' �� v '' �f � r � f � 11•'"d%% � t d R }° Z a L' i � . �� r ;,,. °M. ,.,. �„• µ' �� . S � � o J
� \ �� \l `�� �`� /� l l � �, `"••=-,F� "—� f ro n ��o y�( y {� (�', �f �s l � ''°� ' .� � -, .� s•s''' c a %� .�` � i { �
1225 LF OF �o ° s a EG, 7611?6o i
SHEET FLOW
Jim.
r• 255 LF OF �� w
CHANNEL FLOW
g / dNEW ® 1.64%SRI
/ I
I �
of R/W VARIESJi
� I I
I
—� —L
1-85 COMMERCE CENTER
STORMWATER REPORT
PRE DEVELOPMENT EXHIBIT
CLIENT:
NORTHPOINT DEVELOPMENT
LOCATION: 410 WEBB RD, SALISBURY, NC 28146
DATE: June 30, 2021 DRAWN BY: NH
JOB NUMBER: J-29101.0000 REVIEWED BY: WBS
SHEET: 1
SCALE: 1 " = 300'
wis
T THOMAS
H HUTTON
1020 Euclid Avenue
Charlotte, NC 28202 • 980.201.5505
www.thomasandhutton.com

SSA NETWORK DIAGRAM
PRE -DEVELOPMENT

STORMWATER MANAGEMENT REPORT
1-85 COMMERCE CENTER
APPENDIX C
PRE -DEVELOPMENT CONDITIONS
DRAINAGE CALCULATIONS
A THOMAS & HUTTON

Pre -Development 002 - Year Page 1
Project Description
File Name .................................................... 29101.0000 - Pre Development.SPF
Project Options
Flow Units ---------------------------------------------------
CFS
Elevation Type
Elevation
Hydrology Method .
SCS TR-55
Time of Concentration (TOC) Method --------
SCS TR-55
Link Routing Method
Hydrodynamic
Enable Overflow Ponding at Nodes ------------
YES
Skip Steady State Analysis Time Periods ---
NO
Analysis Options
Start Analysis On .
Mar 30, 2021
00:00:00
End Analysis On .
Mar 31, 2021
00:00:00
Start Reporting On .
Mar 30, 2021
00:00:00
Antecedent Dry Days
0
days
Runoff (Dry Weather) Time Step ----------------
0 01:00:00
days hh:mm:ss
Runoff (Wet Weather) Time Step ---------------
0 00:05:00
days hh:mm:ss
Reporting Time Step -----------------------------------
0 00:05:00
days hh:mm:ss
Routing Time Step --------------------------------------
30
seconds
Number of Elements
Qty
Rain Gages
1
Subbasins
1
Nodes
1
Junctions
0
Outfalls
1
Flow Diversions
0
Inlets
0
Storage Nodes
0
Links
0
Channels
0
Pipes
0
Pumps
0
Orifices
0
Weirs
0
Outlets
0
Pollutants
0
Land Uses
0
Rainfall Details
SN Rain Gage Data Data Source Rainfall Rain State County Return Rainfall Rainfall
ID Source ID Type Units Period Depth Distribution
(years) (inches)
1 Time Series TS-002 Intensity inches North Carolina Rowan 2 3.50 SCS Type II 247hr

Pre -Development 002 - Year Page 2
Subbasin Summary
SN Subbasin Area Peak Rate Weighted
ID Factor Curve
Number
Total Total Total Peak Time of
Rainfall Runoff Runoff Runoff Concentration
Volume
(ac) (in) (in) (ac-in) (cfs) (days hh:mm:ss)
1 Sub-01 40.50 484.00 7224 3.50 1.14 45.97 22.36 0 01-03-49

Pre -Development 002 - Year Page 3
Node Summary
SN Element Element Invert Ground/Rim
Initial Surcharge Ponded Peak Max HGL
Max
Min Time of
Total Total Time
ID Type Elevation (Max)
Water Elevation Area Inflow Elevation Surcharge Freeboard Peak
Flooded Flooded
Elevation Elevation Attained
Depth
Attained Flooding
Volume
Attained
Occurrence
(ft) (ft)
(ft) (ft) (ft') (cfs) (ft)
(ft)
(ft) (days hh:mm)
(ac-in) (min)
1 Out-01 Outfall 758.00
0.00 0.00

Pre -Development 002 - Year
Subbasin Hydrology
Page 4
Subbasin : Sub-01
Input Data
Area(ac)------------------------------------------------------------------------
40.50
Peak Rate Factor-----------------------------------------------------------
484.00
Weighted Curve Number-----------------------------------------------
7224
Rain Gage ID .
Rain Gage-001
Composite Curve Number
Area
Soil
Curve
Soil/Surface Description
(acres)
Group Number
> 75 % grass cover, Good
9.07
B
61.00
> 75 % grass cover, Good
15.90
C
74.00
Woods, Good
15.53
D
77.00
Composite Area & Weighted CN
40.50
7224
Time of Concentration
TOC Method : SCS TR-55
Sheet Flow Equation :
Tc = (0.007 * ((n * Lf)^0.8)) / ((P^0.5) * (Sf^0.4))
Where :
Tc =
Time of Concentration (hr)
n =
Manning's roughness
Lf =
Flow Length (ft)
P =
2 yr, 24 hr Rainfall (inches)
Sf =
Slope (ft/ft)
Shallow Concentrated Flow Equation :
V = 16.1345 * (Sf^0.5) (unpaved surface)
V = 20.3282 * (Sf^0.5) (paved surface)
V = 15.0 * (Sf^0.5) (grassed waterway surface)
V = 10.0 * (Sf^0.5) (nearly bare & untilled surface)
V = 9.0 * (Sf^0.5) (cultivated straight rows surface)
V = 7.0 * (Sf^0.5) (short grass pasture surface)
V = 5.0 * (Sf^0.5) (woodland surface)
V = 2.5 * (Sf^0.5) (forest w/heavy litter surface)
Tc = (Lf / V) / (3600 sec/hr)
Where
Tc = Time of Concentration (hr)
Lf = Flow Length (ft)
V = Velocity (ft/sec)
Sf = Slope (ft/ft)
Channel Flow Equation:
V = (1.49 * (R^(2/3)) * (Sf^0.5)) / n
R =Aq/Wp
Tc = (Lf / V) / (3600 sec/hr)
Where :
Tc =
Time of Concentration (hr)
Lf =
Flow Length (ft)
R =
Hydraulic Radius (ft)
Aq =
Flow Area (W)
Wp
= Wetted Perimeter (ft)
V =
Velocity (ft/sec)
Sf =
Slope (ft/ft)
n =
Manning's roughness

Pre -Development
002 - Year
Subarea
Subarea
Subarea
Sheet Flow Computations
A
B
C
Manning's Roughness :
0-4
0-00
0-00
Flow Length (ft) :
100
0-00
0-00
Slope (%) :
2-11
0-00
0-00
2 yr, 24 hr Rainfall (in) :
3-50
0-00
0-00
Velocity (ft/sec) :
0-08
0-00
0-00
Computed Flow Time (min) :
20-10
0-00
0-00
Subarea
Subarea
Subarea
Shallow Concentrated Flow Computations
A
B
C
Flow Length (ft) :
438
1225
0-00
Slope (%) :
4-38
1-87
0-00
Surface Type :
Grass pasture Woodland
Unpaved
Velocity (ft/sec) :
1-46
0-68
0-00
Computed Flow Time (min) :
5-00
30-02
0-00
Subarea
Subarea
Subarea
Channel Flow Computations
A
B
C
Manning's Roughness :
027
0-00
0-00
Flow Length (ft) :
255
0-00
0-00
Channel Slope (%) :
1-64
0-00
0-00
Cross Section Area (ft2) :
31
0-00
0-00
Wetted Perimeter (ft) :
54
0-00
0-00
Velocity (ft/sec) :
0-49
0-00
0-00
Computed Flow Time (min) :
8-71
0-00
0-00
Total TOC (min)------------------63-83
Subbasin Runoff Results
Total Rainfall (in)------------------------------------------------------------ 3-50
Total Runoff (in)------------------------------------------------------------- 1-14
Peak Runoff (cfs)----------------------------------------------------------- 22-36
Weighted Curve Number----------------------------------------------- 7224
Time of Concentration (days hh:mm:ss)------------------------ 0 01-03-50
Page 5

Pre -Development 002 - Year Page 6
Subbasin : Sub-01
6
4.8
4.6
44
4.2
4
3.8
3.6
3.4
3.2
3
2.8
2.6
2.4
2.2
2
1.8
1.6
1.4
1.2
1
0.8
0.6
0.4
0.2
24
23
22
21
20
19
18
17
16
16
14
N
13
w 12
0
11
10
9
8
7
6
6
4
3
2
1
Rainfall Intensity Graph
0 1 2 3 4 6 6 7 8 9 10 11 12 13 14 16 16 17 18 19 20 21 22 23
Time [hrs]
Runoff Hydrograph
0 1 2 3 4 6 6 7 8 9 10 11 12 13 14 16 16 17 18 19 20 21 22 23
Time [hrs]

Pre -Development 010 - Year Page 1
Project Description
File Name .................................................... 29101.0000 - Pre Development.SPF
Project Options
Flow Units ---------------------------------------------------
CFS
Elevation Type
Elevation
Hydrology Method .
SCS TR-55
Time of Concentration (TOC) Method --------
SCS TR-55
Link Routing Method
Hydrodynamic
Enable Overflow Ponding at Nodes ------------
YES
Skip Steady State Analysis Time Periods ---
NO
Analysis Options
Start Analysis On .
Mar 30, 2021
00:00:00
End Analysis On .
Mar 31, 2021
00:00:00
Start Reporting On .
Mar 30, 2021
00:00:00
Antecedent Dry Days
0
days
Runoff (Dry Weather) Time Step ----------------
0 01:00:00
days hh:mm:ss
Runoff (Wet Weather) Time Step ---------------
0 00:05:00
days hh:mm:ss
Reporting Time Step -----------------------------------
0 00:05:00
days hh:mm:ss
Routing Time Step --------------------------------------
30
seconds
Number of Elements
Qty
Rain Gages
1
Subbasins
1
Nodes
1
Junctions
0
Outfalls
1
Flow Diversions
0
Inlets
0
Storage Nodes
0
Links
0
Channels
0
Pipes
0
Pumps
0
Orifices
0
Weirs
0
Outlets
0
Pollutants
0
Land Uses
0
Rainfall Details
SN Rain Gage Data Data Source Rainfall Rain State County Return Rainfall Rainfall
ID Source ID Type Units Period Depth Distribution
(years) (inches)
1 Time Series TS-010 Intensity inches North Carolina Rowan 10 5.10 SCS Type II 247hr

Pre -Development 010 - Year Page 2
Subbasin Summary
SN Subbasin Area Peak Rate Weighted
ID Factor Curve
Number
Total Total Total Peak Time of
Rainfall Runoff Runoff Runoff Concentration
Volume
(ac) (in) (in) (ac-in) (cfs) (days hh:mm:ss)
1 Sub-01 40.50 484.00 7224 5.10 2.30 92.95 4828 0 01-03-49

Pre -Development 010 - Year Page 3
Node Summary
SN Element Element Invert Ground/Rim
Initial Surcharge Ponded Peak Max HGL
Max
Min Time of
Total Total Time
ID Type Elevation (Max)
Water Elevation Area Inflow Elevation Surcharge Freeboard Peak
Flooded Flooded
Elevation Elevation Attained
Depth
Attained Flooding
Volume
Attained
Occurrence
(ft) (ft)
(ft) (ft) (ft') (cfs) (ft)
(ft)
(ft) (days hh:mm)
(ac-in) (min)
1 Out-01 Outfall 758.00
0.00 0.00

Pre -Development 010 - Year
Subbasin Hydrology
Page 4
Subbasin : Sub-01
Input Data
Area(ac)------------------------------------------------------------------------
40.50
Peak Rate Factor-----------------------------------------------------------
484.00
Weighted Curve Number-----------------------------------------------
7224
Rain Gage ID .
Rain Gage-001
Composite Curve Number
Area
Soil
Curve
Soil/Surface Description
(acres)
Group Number
> 75 % grass cover, Good
9.07
B
61.00
> 75 % grass cover, Good
15.90
C
74.00
Woods, Good
15.53
D
77.00
Composite Area & Weighted CN
40.50
7224
Time of Concentration
TOC Method : SCS TR-55
Sheet Flow Equation :
Tc = (0.007 * ((n * Lf)^0.8)) / ((P^0.5) * (Sf^0.4))
Where :
Tc =
Time of Concentration (hr)
n =
Manning's roughness
Lf =
Flow Length (ft)
P =
2 yr, 24 hr Rainfall (inches)
Sf =
Slope (ft/ft)
Shallow Concentrated Flow Equation :
V = 16.1345 * (Sf^0.5) (unpaved surface)
V = 20.3282 * (Sf^0.5) (paved surface)
V = 15.0 * (Sf^0.5) (grassed waterway surface)
V = 10.0 * (Sf^0.5) (nearly bare & untilled surface)
V = 9.0 * (Sf^0.5) (cultivated straight rows surface)
V = 7.0 * (Sf^0.5) (short grass pasture surface)
V = 5.0 * (Sf^0.5) (woodland surface)
V = 2.5 * (Sf^0.5) (forest w/heavy litter surface)
Tc = (Lf / V) / (3600 sec/hr)
Where
Tc = Time of Concentration (hr)
Lf = Flow Length (ft)
V = Velocity (ft/sec)
Sf = Slope (ft/ft)
Channel Flow Equation:
V = (1.49 * (R^(2/3)) * (Sf^0.5)) / n
R =Aq/Wp
Tc = (Lf / V) / (3600 sec/hr)
Where :
Tc =
Time of Concentration (hr)
Lf =
Flow Length (ft)
R =
Hydraulic Radius (ft)
Aq =
Flow Area (W)
Wp
= Wetted Perimeter (ft)
V =
Velocity (ft/sec)
Sf =
Slope (ft/ft)
n =
Manning's roughness

Pre -Development
010 - Year
Subarea
Subarea
Subarea
Sheet Flow Computations
A
B
C
Manning's Roughness :
0-4
0-00
0-00
Flow Length (ft) :
100
0-00
0-00
Slope (%) :
2-11
0-00
0-00
2 yr, 24 hr Rainfall (in) :
3-50
0-00
0-00
Velocity (ft/sec) :
0-08
0-00
0-00
Computed Flow Time (min) :
20-10
0-00
0-00
Subarea
Subarea
Subarea
Shallow Concentrated Flow Computations
A
B
C
Flow Length (ft) :
438
1225
0-00
Slope (%) :
4-38
1-87
0-00
Surface Type :
Grass pasture Woodland
Unpaved
Velocity (ft/sec) :
1-46
0-68
0-00
Computed Flow Time (min) :
5-00
30-02
0-00
Subarea
Subarea
Subarea
Channel Flow Computations
A
B
C
Manning's Roughness :
027
0-00
0-00
Flow Length (ft) :
255
0-00
0-00
Channel Slope (%) :
1-64
0-00
0-00
Cross Section Area (ft2) :
31
0-00
0-00
Wetted Perimeter (ft) :
54
0-00
0-00
Velocity (ft/sec) :
0-49
0-00
0-00
Computed Flow Time (min) :
8-71
0-00
0-00
Total TOC (min)------------------63-83
Subbasin Runoff Results
Total Rainfall (in)------------------------------------------------------------ 5-10
Total Runoff (in)------------------------------------------------------------- 2-30
Peak Runoff (cfs)----------------------------------------------------------- 4828
Weighted Curve Number----------------------------------------------- 7224
Time of Concentration (days hh:mm:ss)------------------------ 0 01-03-50
Page 5

Pre -Development 010 - Year Page 6
Subbasin : Sub-01
7.6
7
6.6
6
5.6
6
4.6
4
3.6
3
2.6
2
1.6
0.6
60
48
46
44
42
40
38
36
34
32
30
N 28
L�
26
0 24
22
20
18
16
14
12
10
8
6
4
2
Rainfall Intensity Graph
0 1 2 3 4 6 6 7 8 9 10 11 12 13 14 16 16 17 18 19 20 21 22 23
Time [hrs]
Runoff Hydrograph
0 1 2 3 4 6 6 7 8 9 10 11 12 13 14 16 16 17 18 19 20 21 22 23
Time [hrs]

Pre -Development 025 - Year Page 1
Project Description
File Name .................................................... 29101.0000 - Pre Development.SPF
Project Options
Flow Units ---------------------------------------------------
CFS
Elevation Type
Elevation
Hydrology Method .
SCS TR-55
Time of Concentration (TOC) Method --------
SCS TR-55
Link Routing Method
Hydrodynamic
Enable Overflow Ponding at Nodes ------------
YES
Skip Steady State Analysis Time Periods ---
NO
Analysis Options
Start Analysis On .
Mar 30, 2021
00:00:00
End Analysis On .
Mar 31, 2021
00:00:00
Start Reporting On .
Mar 30, 2021
00:00:00
Antecedent Dry Days
0
days
Runoff (Dry Weather) Time Step ----------------
0 01:00:00
days hh:mm:ss
Runoff (Wet Weather) Time Step ---------------
0 00:05:00
days hh:mm:ss
Reporting Time Step -----------------------------------
0 00:05:00
days hh:mm:ss
Routing Time Step --------------------------------------
30
seconds
Number of Elements
Qty
Rain Gages
1
Subbasins
1
Nodes
1
Junctions
0
Outfalls
1
Flow Diversions
0
Inlets
0
Storage Nodes
0
Links
0
Channels
0
Pipes
0
Pumps
0
Orifices
0
Weirs
0
Outlets
0
Pollutants
0
Land Uses
0
Rainfall Details
SN Rain Gage Data Data Source Rainfall Rain State County Return Rainfall Rainfall
ID Source ID Type Units Period Depth Distribution
(years) (inches)
1 Time Series TS-025 Intensity inches North Carolina Rowan 25 6.00 SCS Type II 247hr

Pre -Development 025 - Year Page 2
Subbasin Summary
SN Subbasin Area Peak Rate Weighted
ID Factor Curve
Number
Total Total Total Peak Time of
Rainfall Runoff Runoff Runoff Concentration
Volume
(ac) (in) (in) (ac-in) (cfs) (days hh:mm:ss)
1 Sub-01 40.50 484.00 7224 6.00 3.02 122.15 63.98 0 01-03-49

Pre -Development 025 - Year Page 3
Node Summary
SN Element Element Invert Ground/Rim
Initial Surcharge Ponded Peak Max HGL
Max
Min Time of
Total Total Time
ID Type Elevation (Max)
Water Elevation Area Inflow Elevation Surcharge Freeboard Peak
Flooded Flooded
Elevation Elevation Attained
Depth
Attained Flooding
Volume
Attained
Occurrence
(ft) (ft)
(ft) (ft) (ft2) (cfs) (ft)
(ft)
(ft) (days hh:mm)
(ac-in) (min)
1 Out-01 Outfall 758.00
0.00 0.00

Pre -Development 025 - Year
Subbasin Hydrology
Page 4
Subbasin : Sub-01
Input Data
Area(ac)------------------------------------------------------------------------
40.50
Peak Rate Factor-----------------------------------------------------------
484.00
Weighted Curve Number-----------------------------------------------
7224
Rain Gage ID .
Rain Gage-001
Composite Curve Number
Area
Soil
Curve
Soil/Surface Description
(acres)
Group Number
> 75 % grass cover, Good
9.07
B
61.00
> 75 % grass cover, Good
15.90
C
74.00
Woods, Good
15.53
D
77.00
Composite Area & Weighted CN
40.50
7224
Time of Concentration
TOC Method : SCS TR-55
Sheet Flow Equation :
Tc = (0.007 * ((n * Lf)^0.8)) / ((P^0.5) * (Sf^0.4))
Where :
Tc =
Time of Concentration (hr)
n =
Manning's roughness
Lf =
Flow Length (ft)
P =
2 yr, 24 hr Rainfall (inches)
Sf =
Slope (ft/ft)
Shallow Concentrated Flow Equation :
V = 16.1345 * (Sf^0.5) (unpaved surface)
V = 20.3282 * (Sf^0.5) (paved surface)
V = 15.0 * (Sf^0.5) (grassed waterway surface)
V = 10.0 * (Sf^0.5) (nearly bare & untilled surface)
V = 9.0 * (Sf^0.5) (cultivated straight rows surface)
V = 7.0 * (Sf^0.5) (short grass pasture surface)
V = 5.0 * (Sf^0.5) (woodland surface)
V = 2.5 * (Sf^0.5) (forest w/heavy litter surface)
Tc = (Lf / V) / (3600 sec/hr)
Where
Tc = Time of Concentration (hr)
Lf = Flow Length (ft)
V = Velocity (ft/sec)
Sf = Slope (ft/ft)
Channel Flow Equation:
V = (1.49 * (R^(2/3)) * (Sf^0.5)) / n
R =Aq/Wp
Tc = (Lf / V) / (3600 sec/hr)
Where :
Tc =
Time of Concentration (hr)
Lf =
Flow Length (ft)
R =
Hydraulic Radius (ft)
Aq =
Flow Area (W)
Wp
= Wetted Perimeter (ft)
V =
Velocity (ft/sec)
Sf =
Slope (ft/ft)
n =
Manning's roughness

Pre -Development
025 - Year
Subarea
Subarea
Subarea
Sheet Flow Computations
A
B
C
Manning's Roughness :
0-4
0-00
0-00
Flow Length (ft) :
100
0-00
0-00
Slope (%) :
2-11
0-00
0-00
2 yr, 24 hr Rainfall (in) :
3-50
0-00
0-00
Velocity (ft/sec) :
0-08
0-00
0-00
Computed Flow Time (min) :
20-10
0-00
0-00
Subarea
Subarea
Subarea
Shallow Concentrated Flow Computations
A
B
C
Flow Length (ft) :
438
1225
0-00
Slope (%) :
4-38
1-87
0-00
Surface Type :
Grass pasture Woodland
Unpaved
Velocity (ft/sec) :
1-46
0-68
0-00
Computed Flow Time (min) :
5-00
30-02
0-00
Subarea
Subarea
Subarea
Channel Flow Computations
A
B
C
Manning's Roughness :
027
0-00
0-00
Flow Length (ft) :
255
0-00
0-00
Channel Slope (%) :
1-64
0-00
0-00
Cross Section Area (ft2) :
31
0-00
0-00
Wetted Perimeter (ft) :
54
0-00
0-00
Velocity (ft/sec) :
0-49
0-00
0-00
Computed Flow Time (min) :
8-71
0-00
0-00
Total TOC (min)------------------63-83
Subbasin Runoff Results
Total Rainfall (in)------------------------------------------------------------ 6-00
Total Runoff (in)------------------------------------------------------------- 3-02
Peak Runoff (cfs)----------------------------------------------------------- 63-98
Weighted Curve Number----------------------------------------------- 7224
Time of Concentration (days hh:mm:ss)------------------------ 0 01-03-50
Page 5

Pre -Development 025 - Year Page 6
Subbasin : Sub-01
s.5
s
7.6
7
65
6
5.6
5
v 4.6
4
3.5
3
2.5
2
1.6
0.6
70
65
60
55
50
45
N 40
w 35
0
30
25
20
15
10
5
Rainfall Intensity Graph
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23
Time [hrs]
Runoff Hydrograph
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23
Time [hrs]

Pre -Development 050 - Year Page 1
Project Description
File Name .................................................... 29101.0000 - Pre Development.SPF
Project Options
Flow Units ---------------------------------------------------
CFS
Elevation Type
Elevation
Hydrology Method .
SCS TR-55
Time of Concentration (TOC) Method --------
SCS TR-55
Link Routing Method
Hydrodynamic
Enable Overflow Ponding at Nodes ------------
YES
Skip Steady State Analysis Time Periods ---
NO
Analysis Options
Start Analysis On .
Mar 30, 2021
00:00:00
End Analysis On .
Mar 31, 2021
00:00:00
Start Reporting On .
Mar 30, 2021
00:00:00
Antecedent Dry Days
0
days
Runoff (Dry Weather) Time Step ----------------
0 01:00:00
days hh:mm:ss
Runoff (Wet Weather) Time Step ---------------
0 00:05:00
days hh:mm:ss
Reporting Time Step -----------------------------------
0 00:05:00
days hh:mm:ss
Routing Time Step --------------------------------------
30
seconds
Number of Elements
Qty
Rain Gages
1
Subbasins
1
Nodes
1
Junctions
0
Outfalls
1
Flow Diversions
0
Inlets
0
Storage Nodes
0
Links
0
Channels
0
Pipes
0
Pumps
0
Orifices
0
Weirs
0
Outlets
0
Pollutants
0
Land Uses
0
Rainfall Details
SN Rain Gage Data Data Source Rainfall Rain State County Return Rainfall Rainfall
ID Source ID Type Units Period Depth Distribution
(years) (inches)
1 Time Series TS-050 Intensity inches North Carolina Rowan 50 6.50 SCS Type II 247hr

Pre -Development 050 - Year Page 2
Subbasin Summary
SN Subbasin Area Peak Rate Weighted
ID Factor Curve
Number
Total Total Total Peak Time of
Rainfall Runoff Runoff Runoff Concentration
Volume
(ac) (in) (in) (ac-in) (cfs) (days hh:mm:ss)
1 Sub-01 40.50 484.00 7224 6.50 3.43 138.96 7327 0 01-03-49

Pre -Development 050 - Year Page 3
Node Summary
SN Element Element Invert Ground/Rim
Initial Surcharge Ponded Peak Max HGL
Max
Min Time of
Total Total Time
ID Type Elevation (Max)
Water Elevation Area Inflow Elevation Surcharge Freeboard Peak
Flooded Flooded
Elevation Elevation Attained
Depth
Attained Flooding
Volume
Attained
Occurrence
(ft) (ft)
(ft) (ft) (ft') (cfs) (ft)
(ft)
(ft) (days hh:mm)
(ac-in) (min)
1 Out-01 Outfall 758.00
0.00 0.00

Pre -Development 050 - Year
Subbasin Hydrology
Page 4
Subbasin : Sub-01
Input Data
Area(ac)------------------------------------------------------------------------
40.50
Peak Rate Factor-----------------------------------------------------------
484.00
Weighted Curve Number-----------------------------------------------
7224
Rain Gage ID .
Rain Gage-001
Composite Curve Number
Area
Soil
Curve
Soil/Surface Description
(acres)
Group Number
> 75 % grass cover, Good
9.07
B
61.00
> 75 % grass cover, Good
15.90
C
74.00
Woods, Good
15.53
D
77.00
Composite Area & Weighted CN
40.50
7224
Time of Concentration
TOC Method : SCS TR-55
Sheet Flow Equation :
Tc = (0.007 * ((n * Lf)^0.8)) / ((P^0.5) * (Sf^0.4))
Where :
Tc =
Time of Concentration (hr)
n =
Manning's roughness
Lf =
Flow Length (ft)
P =
2 yr, 24 hr Rainfall (inches)
Sf =
Slope (ft/ft)
Shallow Concentrated Flow Equation :
V = 16.1345 * (Sf^0.5) (unpaved surface)
V = 20.3282 * (Sf^0.5) (paved surface)
V = 15.0 * (Sf^0.5) (grassed waterway surface)
V = 10.0 * (Sf^0.5) (nearly bare & untilled surface)
V = 9.0 * (Sf^0.5) (cultivated straight rows surface)
V = 7.0 * (Sf^0.5) (short grass pasture surface)
V = 5.0 * (Sf^0.5) (woodland surface)
V = 2.5 * (Sf^0.5) (forest w/heavy litter surface)
Tc = (Lf / V) / (3600 sec/hr)
Where
Tc = Time of Concentration (hr)
Lf = Flow Length (ft)
V = Velocity (ft/sec)
Sf = Slope (ft/ft)
Channel Flow Equation:
V = (1.49 * (R^(2/3)) * (Sf^0.5)) / n
R =Aq/Wp
Tc = (Lf / V) / (3600 sec/hr)
Where :
Tc =
Time of Concentration (hr)
Lf =
Flow Length (ft)
R =
Hydraulic Radius (ft)
Aq =
Flow Area (W)
Wp
= Wetted Perimeter (ft)
V =
Velocity (ft/sec)
Sf =
Slope (ft/ft)
n =
Manning's roughness

Pre -Development
050 - Year
Subarea
Subarea
Subarea
Sheet Flow Computations
A
B
C
Manning's Roughness :
0-4
0-00
0-00
Flow Length (ft) :
100
0-00
0-00
Slope (%) :
2-11
0-00
0-00
2 yr, 24 hr Rainfall (in) :
3-50
0-00
0-00
Velocity (ft/sec) :
0-08
0-00
0-00
Computed Flow Time (min) :
20-10
0-00
0-00
Subarea
Subarea
Subarea
Shallow Concentrated Flow Computations
A
B
C
Flow Length (ft) :
438
1225
0-00
Slope (%) :
4-38
1-87
0-00
Surface Type :
Grass pasture Woodland
Unpaved
Velocity (ft/sec) :
1-46
0-68
0-00
Computed Flow Time (min) :
5-00
30-02
0-00
Subarea
Subarea
Subarea
Channel Flow Computations
A
B
C
Manning's Roughness :
027
0-00
0-00
Flow Length (ft) :
255
0-00
0-00
Channel Slope (%) :
1-64
0-00
0-00
Cross Section Area (ft2) :
31
0-00
0-00
Wetted Perimeter (ft) :
54
0-00
0-00
Velocity (ft/sec) :
0-49
0-00
0-00
Computed Flow Time (min) :
8-71
0-00
0-00
Total TOC (min)------------------63-83
Subbasin Runoff Results
Total Rainfall (in)------------------------------------------------------------ 6-50
Total Runoff (in)------------------------------------------------------------- 3-43
Peak Runoff (cfs)----------------------------------------------------------- 7327
Weighted Curve Number----------------------------------------------- 7224
Time of Concentration (days hh:mm:ss)------------------------ 0 01-03-50
Page 5

Pre -Development 050 - Year Page 6
Subbasin : Sub-01
9
8.5
8
7.6
7
6.6
6
5.6
� 5
4.6
4
Or
3.6
3
2.6
2
1.6
0.6
80
75
70
65
60
55
50
N 45
L�
w 40
O
C
35
30
25
20
15
10
5
Rainfall Intensity Graph
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23
Time [hrs]
Runoff Hydrograph
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23
Time [hrs]

Pre -Development 050 - Year Page 1
Project Description
File Name .................................................... 29101.0000 - Pre Development.SPF
Project Options
Flow Units ---------------------------------------------------
CFS
Elevation Type
Elevation
Hydrology Method .
SCS TR-55
Time of Concentration (TOC) Method --------
SCS TR-55
Link Routing Method
Hydrodynamic
Enable Overflow Ponding at Nodes ------------
YES
Skip Steady State Analysis Time Periods ---
NO
Analysis Options
Start Analysis On .
Mar 30, 2021
00:00:00
End Analysis On .
Mar 31, 2021
00:00:00
Start Reporting On .
Mar 30, 2021
00:00:00
Antecedent Dry Days
0
days
Runoff (Dry Weather) Time Step ----------------
0 01:00:00
days hh:mm:ss
Runoff (Wet Weather) Time Step ---------------
0 00:05:00
days hh:mm:ss
Reporting Time Step -----------------------------------
0 00:05:00
days hh:mm:ss
Routing Time Step --------------------------------------
30
seconds
Number of Elements
Qty
Rain Gages
1
Subbasins
1
Nodes
1
Junctions
0
Outfalls
1
Flow Diversions
0
Inlets
0
Storage Nodes
0
Links
0
Channels
0
Pipes
0
Pumps
0
Orifices
0
Weirs
0
Outlets
0
Pollutants
0
Land Uses
0
Rainfall Details
SN Rain Gage Data Data Source Rainfall Rain State County Return Rainfall Rainfall
ID Source ID Type Units Period Depth Distribution
(years) (inches)
1 Time Series TS-100 Intensity inches North Carolina Rowan 100 720 SCS Type II 247

Pre -Development 050 - Year Page 2
Subbasin Summary
SN Subbasin Area Peak Rate Weighted
ID Factor Curve
Number
Total Total Total Peak Time of
Rainfall Runoff Runoff Runoff Concentration
Volume
(ac) (in) (in) (ac-in) (cfs) (days hh:mm:ss)
1 Sub-01 40.50 484.00 7224 720 4.03 163.05 86.30 0 01-03-49

Pre -Development 050 - Year Page 3
Node Summary
SN Element Element Invert Ground/Rim
Initial Surcharge Ponded Peak Max HGL
Max
Min Time of
Total Total Time
ID Type Elevation (Max)
Water Elevation Area Inflow Elevation Surcharge Freeboard Peak
Flooded Flooded
Elevation Elevation Attained
Depth
Attained Flooding
Volume
Attained
Occurrence
(ft) (ft)
(ft) (ft) (ft') (cfs) (ft)
(ft)
(ft) (days hh:mm)
(ac-in) (min)
1 Out-01 Outfall 758.00
0.00 0.00

Pre -Development 050 - Year
Subbasin Hydrology
Page 4
Subbasin : Sub-01
Input Data
Area(ac)------------------------------------------------------------------------
40.50
Peak Rate Factor-----------------------------------------------------------
484.00
Weighted Curve Number-----------------------------------------------
7224
Rain Gage ID .
Rain Gage-001
Composite Curve Number
Area
Soil
Curve
Soil/Surface Description
(acres)
Group Number
> 75 % grass cover, Good
9.07
B
61.00
> 75 % grass cover, Good
15.90
C
74.00
Woods, Good
15.53
D
77.00
Composite Area & Weighted CN
40.50
7224
Time of Concentration
TOC Method : SCS TR-55
Sheet Flow Equation :
Tc = (0.007 * ((n * Lf)^0.8)) / ((P^0.5) * (Sf^0.4))
Where :
Tc =
Time of Concentration (hr)
n =
Manning's roughness
Lf =
Flow Length (ft)
P =
2 yr, 24 hr Rainfall (inches)
Sf =
Slope (ft/ft)
Shallow Concentrated Flow Equation :
V = 16.1345 * (Sf^0.5) (unpaved surface)
V = 20.3282 * (Sf^0.5) (paved surface)
V = 15.0 * (Sf^0.5) (grassed waterway surface)
V = 10.0 * (Sf^0.5) (nearly bare & untilled surface)
V = 9.0 * (Sf^0.5) (cultivated straight rows surface)
V = 7.0 * (Sf^0.5) (short grass pasture surface)
V = 5.0 * (Sf^0.5) (woodland surface)
V = 2.5 * (Sf^0.5) (forest w/heavy litter surface)
Tc = (Lf / V) / (3600 sec/hr)
Where
Tc = Time of Concentration (hr)
Lf = Flow Length (ft)
V = Velocity (ft/sec)
Sf = Slope (ft/ft)
Channel Flow Equation:
V = (1.49 * (R^(2/3)) * (Sf^0.5)) / n
R =Aq/Wp
Tc = (Lf / V) / (3600 sec/hr)
Where :
Tc =
Time of Concentration (hr)
Lf =
Flow Length (ft)
R =
Hydraulic Radius (ft)
Aq =
Flow Area (W)
Wp
= Wetted Perimeter (ft)
V =
Velocity (ft/sec)
Sf =
Slope (ft/ft)
n =
Manning's roughness

Pre -Development
050 - Year
Subarea
Subarea
Subarea
Sheet Flow Computations
A
B
C
Manning's Roughness :
0-4
0-00
0-00
Flow Length (ft) :
100
0-00
0-00
Slope (%) :
2-11
0-00
0-00
2 yr, 24 hr Rainfall (in) :
3-50
0-00
0-00
Velocity (ft/sec) :
0-08
0-00
0-00
Computed Flow Time (min) :
20-10
0-00
0-00
Subarea
Subarea
Subarea
Shallow Concentrated Flow Computations
A
B
C
Flow Length (ft) :
438
1225
0-00
Slope (%) :
4-38
1-87
0-00
Surface Type :
Grass pasture Woodland
Unpaved
Velocity (ft/sec) :
1-46
0-68
0-00
Computed Flow Time (min) :
5-00
30-02
0-00
Subarea
Subarea
Subarea
Channel Flow Computations
A
B
C
Manning's Roughness :
027
0-00
0-00
Flow Length (ft) :
255
0-00
0-00
Channel Slope (%) :
1-64
0-00
0-00
Cross Section Area (ft2) :
31
0-00
0-00
Wetted Perimeter (ft) :
54
0-00
0-00
Velocity (ft/sec) :
0-49
0-00
0-00
Computed Flow Time (min) :
8-71
0-00
0-00
Total TOC (min)------------------63-83
Subbasin Runoff Results
Total Rainfall (in)------------------------------------------------------------ 720
Total Runoff (in)------------------------------------------------------------- 4-03
Peak Runoff (cfs)----------------------------------------------------------- 86-30
Weighted Curve Number----------------------------------------------- 7224
Time of Concentration (days hh:mm:ss)------------------------ 0 01-03-50
Page 5

Pre -Development 050 - Year Page 6
Subbasin : Sub-01
10
9.6
9
8.6
8
7.5
7
6.6
6
� 5.5
6
4.6
4
3.5
3
2.6
2
1.6
0.6
95
90
85
80
75
70
65
60
55
N
50
45
40
35
30
25
20
15
10
5
Rainfall Intensity Graph
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23
Time [hrs]
Runoff Hydrograph
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23
Time [hrs]

STORMWATER MANAGEMENT REPORT
1-85 COMMERCE CENTER
APPENDIX D
POST -DEVELOPMENT
DRAINAGE MAP
A THOMAS & HUTTON

fr
° POND 1 N
TOP: 770.0 ,
NWL: 764.0 c
l �9ti BTM: 759.0
e
/j/�/�� �f _ s•'�, '�� �_•!� III �6II' •' � �
l� ail i �I n...,�,�����.,,.co. i _ •
l
•
�I
c I�
O�t►
\\ �, � �� i/ ie_. , � , � 'il . � it i�l � � 1J J � `/ •i
VL
I
Will
Will
1-85 COMMERCE CENTER
STORMWATER REPORT
POST DEVELOPMENT EXHIBIT
CLIENT:
NP 185 COMMERCE CENTER INDUSTRIAL, LLC
LOCATION: 410 WEBB RD, SALISBURY, INC 28146
DATE: November 15, 2021 DRAWN BY: NH SHEET: 1
JOB NUMBER: J-29101.0000 REVIEWED BY: WBS SCALE: 1"= 300'
T THOMAS
H HUTTON
1020 Euclid Avenue
Charlotte, INC 28202 • 980.201.5505
www.thomasandhutton.com

SSA NETWORK DIAGRAM
POST -DEVELOPMENT

STORMWATER MANAGEMENT REPORT
1-85 COMMERCE CENTER
APPENDIX E
POST -DEVELOPMENT CONDITIONS
DRAINAGE CALCULATIONS
A THOMAS & HUTTON

Post -Development 002 - Year Page 1
Project Description
File Name .................................................... 29101.0000 - Post Development.SPF
Project Options
Flow Units ---------------------------------------------------
CFS
Elevation Type
Elevation
Hydrology Method .
SCS TR-55
Time of Concentration (TOC) Method --------
SCS TR-55
Link Routing Method
Hydrodynamic
Enable Overflow Ponding at Nodes ------------
YES
Skip Steady State Analysis Time Periods ---
NO
Analysis Options
Start Analysis On .
Mar 30, 2021
00:00:00
End Analysis On .
Apr 04, 2021
00:00:00
Start Reporting On .
Mar 30, 2021
00:00:00
Antecedent Dry Days
0
days
Runoff (Dry Weather) Time Step ----------------
0 01:00:00
days hh:mm:ss
Runoff (Wet Weather) Time Step ---------------
0 00:05:00
days hh:mm:ss
Reporting Time Step -----------------------------------
0 00:05:00
days hh:mm:ss
Routing Time Step --------------------------------------
10
seconds
Number of Elements
Qty
Rain Gages
1
Subbasins
2
Nodes
S
Junctions
2
Outfalls
2
Flow Diversions
0
Inlets
0
Storage Nodes
4
Links
10
Channels
1
Pipes
4
Pumps
0
Orifices
2
Weirs
3
Outlets
0
Pollutants
0
Land Uses
0
Rainfall Details
SN Rain Gage Data Data Source Rainfall Rain State County Return Rainfall Rainfall
ID Source ID Type Units Period Depth Distribution
(years) (inches)
1 Time Series TS-002 Intensity inches North Carolina Rowan 2 3.50 SCS Type II 247hr

Post -Development 002 - Year Page 2
Subbasin Summary
SN Subbasin Area Peak Rate Weighted
ID Factor Curve
Number
Total Total Total Peak Time of
Rainfall Runoff Runoff Runoff Concentration
Volume
(ac) (in) (in) (ac-in) (cfs) (days hh:mm:ss)
1 Sub-01 1916.484.00 90.73 3.50 2.52 4821 72.51 0 00-06-00
2 Sub-02 2006.484.00 90.81 3.50 2.52 50.61 76.05 0 00-06-00

Post -Development 002 - Year Page 3
Node Summary
SN Element Element
Invert Ground/Rim
Initial Surcharge Ponded Peak Max HGL
Max
Min
Time of
Total Total Time
ID Type
Elevation
(Max)
Water
Elevation
Area Inflow
Elevation Surcharge Freeboard
Peak Flooded
Flooded
Elevation Elevation
Attained
Depth
Attained
Flooding
Volume
Attained
Occurrence
(ft)
(ft)
(ft)
(ft)
(ft') (cfs)
(ft)
(ft)
(ft) (days hh:mm)
(ac-in)
(min)
1 CS-01 Junction
761.50
770.00
761.50
999.00
0.00 1320
762.62
0.00
11.73
0 00:00
0.00
0.00
2 Jun-01 Junction
760.50
772.00
760.50
999.00
0.00 1320
760.92
0.00
13.59
0 00:00
0.00
0.00
3 Out-01 Outfall
760.40
1320
760.50
4 Out-02 Outfall
768.00
0.00
768.00
5 Pond-01 Storage Node
759.00
770.00
764.00
0.00 11.36
766.74
0.00
0.00
6 Pond-02 Storage Node
756.00
770.00
764.00
0.00 9329
766.74
0.00
0.00
7 Pond-03 Storage Node
756.00
770.00
764.00
0.00 7524
766.75
0.00
0.00
8 Pond-04 Storage Node
759.00
770.00
764.00
0.00 3327
766.75
0.00
0.00

Post -Development 002 - Year
Page 4
Link Summary
SN Element Element From To (Outlet) Length Inlet Outlet Average Diameter or Manning's Peak Design Flow Peak Flow/ Peak Flow Peak Flow Peak Flow Total Time Reported
ID Type (Inlet) Node Invert Invert Slope Height Roughness Flow Capacity Design Flow Velocity Depth Depth/ Surcharged Condition
Node Elevation Elevation Ratio Total Depth
Ratio
(ft)
(ft)
(ft)
( % )
(in)
(cfs)
(cfs)
(ft/sec)
(ft)
(min)
1 Pipe_01
Pipe
CS-01 Jun-01
68.00
761.50
760.50
1.4700
36.000
0.0130 1320
80.88
0.16
926
0.77
026
0.00 Calculated
2 Pipe01-Overflow
Pipe
Pond-02 Pond-01
50.00
764.00
763.90
02000
36.000
0.0150 11.36
51.70
022
1.19
2.79
0.93
0.00 Calculated
3 Pipe-02-Overflow
Pipe
Pond-03 Pond-04
50.00
764.00
763.90
02000
36.000
0.0150 3327
51.70
0.64
3.40
2.79
0.93
0.00 Calculated
4 Pipe-WQ
Pipe
Pond-03 Pond-02
300.00
756.00
756.10
-0.0300
54.000
0.0150 22.41
31.12
0.72
1.41
4.50
1.00
7200.00 SURCHARGED
5 DummyLink_CHNL-01 Channel
Jun-01 Out-01
50.00
760.50
760.40
02000
24.000
0.0010 1320
1685.90
0.01
5.16
026
0.13
0.00
6 TOBox-01
Orifice
Pond-02 CS-01
756.00
761.50
60.000
0.00
7 WQ-01
Orifice
Pond-02 CS-01
756.00
761.50
5.000
1.07
8 ESW-01
Weir
Pond-02 Jun-01
756.00
760.50
0.00
9 ESW-02
Weir
Pond-03 Out-02
756.00
768.00
0.00
10 Weir-01
Weir
Pond-02 CS-01
756.00
761.50
12.13

Post -Development 002 - Year
Subbasin Hydrology
Page 5
Subbasin : Sub-01
Input Data
Area(ac)------------------------------------------------------------------------
1916.
Peak Rate Factor-----------------------------------------------------------
484.00
Weighted Curve Number-----------------------------------------------
90.73
Rain Gage ID .
Rain Gage-001
Composite Curve Number
Area
Soil
Curve
Soil/Surface Description
(acres)
Group
Number
Paved parking & roofs
14.14
C
98.00
> 75 % grass cover, Good
1.45
B
61.00
> 75 % grass cover, Good
3.57
C
74.00
Composite Area & Weighted CN
1916.
90.73
Time of Concentration
TOC Method : SCS TR-55
Sheet Flow Equation :
Tc = (0.007 * ((n * Lf)^0.8)) / ((P^0.5) * (Sf^0.4))
Where :
Tc =
Time of Concentration (hr)
n =
Manning's roughness
Lf =
Flow Length (ft)
P =
2 yr, 24 hr Rainfall (inches)
Sf =
Slope (ft/ft)
Shallow Concentrated Flow Equation :
V = 16.1345 * (Sf^0.5) (unpaved surface)
V = 20.3282 * (Sf^0.5) (paved surface)
V = 15.0 * (Sf^0.5) (grassed waterway surface)
V = 10.0 * (Sf^0.5) (nearly bare & untilled surface)
V = 9.0 * (Sf^0.5) (cultivated straight rows surface)
V = 7.0 * (Sf^0.5) (short grass pasture surface)
V = 5.0 * (Sf^0.5) (woodland surface)
V = 2.5 * (Sf^0.5) (forest w/heavy litter surface)
Tc = (Lf / V) / (3600 sec/hr)
Where
Tc = Time of Concentration (hr)
Lf = Flow Length (ft)
V = Velocity (ft/sec)
Sf = Slope (ft/ft)
Channel Flow Equation:
V = (1.49 * (R^(2/3)) * (Sf^0.5)) / n
R =Aq/Wp
Tc = (Lf / V) / (3600 sec/hr)
Where :
Tc =
Time of Concentration (hr)
Lf =
Flow Length (ft)
R =
Hydraulic Radius (ft)
Aq =
Flow Area (ft)
Wp
= Wetted Perimeter (ft)
V =
Velocity (ft/sec)
Sf =
Slope (ft/ft)
n =
Manning's roughness
User -Defined TOC override (minutes): 6
Subbasin Runoff Results
Total Rainfall (in)------------------------------------------------------------ 3.50
Total Runoff (in)------------------------------------------------------------- 2.52
Peak Runoff (cfs)----------------------------------------------------------- 72.51
Weighted Curve Number----------------------------------------------- 90.73
Time of Concentration (days hh:mm:ss)------------------------ 0 00-06-00

Post -Development 002 - Year Page 6
Subbasin : Sub-01
5
4.8
4.6
44
4.2
4
3.8
3.6
3.4
3.2
3
2.8
2.6
2.4
2.2
2
1.8
1.6
1.4
1.2
1
0.8
0.6
0.4
0.2
Rainfall Intensity Graph
Time [hrs]
Runoff Hydrograph
80
75
70
65
60
65
60
N 45
C]
u 40
O
C
35
30
25
20
15
10
6
0 6 10 15 20 25 30 35 40 45 50 55 60 65 70 76 80 85 90 95 100 105 110 115
Time [hrs]

Post -Development 002 - Year
Subbasin : Sub-02
Page 7
Input Data
Area(ac)------------------------------------------------------------------------ 20-06
Peak Rate Factor----------------------------------------------------------- 484-00
Weighted Curve Number----------------------------------------------- 90-81
Rain Gage ID----------------------------------------------------------------- Rain Gage-001
Composite Curve Number
Area
Soil
Curve
Soil/Surface Description
(acres)
Group
Number
Paved parking & roofs
15-11
A
98-00
> 75 % grass cover, Good
1-95
B
61-00
> 75 % grass cover, Good
3-00
C
74-00
Composite Area & Weighted CN
20-06
90-81
Time of Concentration
User -Defined TOC override (minutes): 6
Subbasin Runoff Results
Total Rainfall (in)------------------------------------------------------------ 3-50
Total Runoff (in)------------------------------------------------------------- 2-52
Peak Runoff (cfs)----------------------------------------------------------- 76-05
Weighted Curve Number----------------------------------------------- 90-81
Time of Concentration (days hh:mm:ss)------------------------ 0 00-06-00

Post -Development 002 - Year Page 8
Subbasin : Sub-02
5
4.8
4.6
44
4.2
4
3.8
3.6
3.4
3.2
3
2.8
2.6
2.4
m 2.2
F 2
1.8
1.6
1.4
1.2
1
0.8
0.6
0.4
0.2
Rainfall Intensity Graph
Time [hrs]
Runoff Hydrograph
85
80
75
70
65
60
55
_ 50
N
C] Q5
40
1h
35
30
25
20
15
10
5
0 6 10 15 20 25 30 35 40 45 50 55 60 65 70 76 80 85 90 95 100 105 110 115
Time [hrs]

Post -Development 002 - Year Page 9
Channel Input
SN Element Length Inlet Inlet
Outlet Outlet Total Average Shape
Height Width Manning's Entrance Exit/Bend Additional Initial
ID Invert Invert
Invert Invert Drop
Slope
Roughness Losses Losses Losses Flow
Elevation Offset Elevation Offset
(ft) (ft) (ft)
(ft) (ft) (ft)
( % )
(ft) (ft) (cfs)
1 DummyLin"HNL-01 50.00 760.50 0.00
760.40 0.00 0.10
02000 Rectangular
2000.10.000 0.0010 0.5000 0.5000 0.0000 0.00

Post -Development 002 - Year Page 11
Channel Results
SN Element Peak Time of Design Flow Peak Flow/ Peak Flow Travel Peak Flow Peak Flow Total Time Froude Reported
ID Flow Peak Flow Capacity Design Flow Velocity Time Depth Depth/ Surcharged Number Condition
Occurrence Ratio Total Depth
Ratio
(cfs) (days hh:mm) (cfs) (ft/sec) (min) (ft) (min)
1 DummyLink_CHNL-01 1320 0 12:34 1685.90 0.01 5.16 0.16 026 0.13 0.00

Post -Development 002 - Year Page 12
Pipe Input
SN Element
Length
Inlet
Inlet
Outlet Outlet Total Average Pipe
Pipe Pipe
Manning's Entrance Exit/Bend Additional Initial Flap
ID
Invert
Invert
Invert Invert Drop
Slope Shape
Diameteror Width
Roughness
Losses
Losses
Losses Flow Gate
Elevation Offset Elevation Offset
Height
(ft)
(ft)
(ft)
(ft) (ft) (ft)
( % )
(in) (in)
(cfs)
1 Pipe_01
68.00
761.50
0.00
760.50 0.00 1.00
1.4700 CIRCULAR
36.000 36.000
0.0130
0.5000
0.5000
0.0000 0.00 No
2 Pipe01-Overflow
50.00
764.00
8.00
763.90 4.90 0.10
02000 CIRCULAR
36.000 36.000
0.0150
0.5000
0.5000
0.0000 0.00 No
3 Pipe-02-Overflow
50.00
764.00
8.00
763.90 4.90 0.10
02000 CIRCULAR
36.000 36.000
0.0150
0.5000
0.5000
0.0000 0.00 No
4 Pipe-WQ
300.00
756.00
0.00
756.10 0.10 -0.10
-0.0300 CIRCULAR
54.000 54.000
0.0150
0.5000
0.5000
0.0000 0.00 No

Post -Development 002 - Year Page 14
Pipe Results
SN Element
Peak
Time of Design Flow
Peak Flow/ Peak Flow Travel Peak Flow
Peak Flow
Total Time
Froude Reported
ID
Flow
Peak Flow
Capacity
Design Flow
Velocity Time
Depth
Depth/
Surcharged
Number Condition
Occurrence
Ratio
Total Depth
Ratio
(cfs) (days hh:mm)
(cfs)
(ft/sec) (min)
(ft)
(min)
1 Pipe_01
1320
0 12:34
80.88
0.16
926 0.12
0.77
026
0.00
Calculated
2 Pipe01-Overflow
11.36
0 12:00
51.70
022
1.19 0.70
2.79
0.93
0.00
Calculated
3 Pipe-02-Overflow
3327
0 12:02
51.70
0.64
3.40 025
2.79
0.93
0.00
Calculated
4 Pipe-WQ
22.41
0 12:01
31.12
0.72
1.41 3.55
4.50
1.00
7200.00
SURCHARGED

Post -Development 002 - Year Page 15
Storage Nodes
Storage Node : Pond-01
Input Data
Invert Elevation (ft)-------------------------------------------------------------
759-00
Max (Rim) Elevation (ft)------------------------------------------------------
770-00
Max (Rim) Offset (ft)-----------------------------------------------------------
11-00
Initial Water Elevation (ft)---------------------------------------------------
764-00
Initial Water Depth (ft)--------------------------------------------------------
5-00
Ponded Area (ftt)----------------------------------------------------------------
0-00
Evaporation Loss----------------------------------------------------------------
0-00
Output Summary Results
Peak Inflow (cfs)-----------------------------------------------------------------
11-36
Peak Lateral Inflow (cfs)-----------------------------------------------------
0-00
Peak Outflow (cfs)--------------------------------------------------------------
0-40
Peak Exfiltration Flow Rate (cfm)---------------------------------------
0-00
Max HGL Elevation Attained (ft)-----------------------------------------
766-74
Max HGL Depth Attained (ft)----------------------------------------------
7-74
Average HGL Elevation Attained (ft)----------------------------------
764-80
Average HGL Depth Attained (ft)---------------------------------------
5-8
Time of Max HGL Occurrence (days hh:mm)--------------------
0 12-34
Total Exfiltration Volume (1000-ft3)------------------------------------
0-000
Total Flooded Volume (ac-in) -
0
Total Time Flooded (min)
0
Total Retention Time (sec) -------------------------------------------------
0-00

Post -Development
002 - Year
Storage Node : Pond-02
Input Data
Invert Elevation (ft)-------------------------------------------------------------
756-00
Max (Rim) Elevation (ft)------------------------------------------------------
770-00
Max (Rim) Offset (ft)-----------------------------------------------------------
14-00
Initial Water Elevation (ft)---------------------------------------------------
764-00
Initial Water Depth (ft)--------------------------------------------------------
8-00
Ponded Area (ft) ----------------------------------------------------------------
0-00
Evaporation Loss----------------------------------------------------------------
0-00
Outflow Weirs
SN Element
Weir Flap
Crest
Crest
Length
Weir Total Discharge
ID
Type Gate
Elevation
Offset
Height Coefficient
(ft)
(ft)
(ft)
(ft)
1 ESW-01
Trapezoidal No
768-71
12-71
60-00
1-30 3-33
2 Weir-01
Rectangular No
765-60
9-60
3-00
325 3-33
Outflow Orifices
SN Element Orifice
Orifice
Flap
Circular Rectangular Rectangular
Orifice Orifice
ID Type
Shape
Gate
Orifice
Orifice
Orifice
Invert Coefficient
Diameter
Height
Width
Elevation
(in)
(in)
(in)
(ft)
1 TOBox-01 Bottom
Rectangular No
60-00
60-00
768-85 0-63
2 WQ-01 Side
CIRCULAR
No
5-00
764-00 0-61
Output Summary Results
Peak Inflow (cfs)-----------------------------------------------------------------
9329
Peak Lateral Inflow (cfs)-----------------------------------------------------
71-78
Peak Outflow (cfs)--------------------------------------------------------------
15-66
Peak Exfiltration Flow Rate (cfm)---------------------------------------
0-00
Max HGL Elevation Attained (ft)-----------------------------------------
766-74
Max HGL Depth Attained (ft)----------------------------------------------
10-74
Average HGL Elevation Attained (ft)----------------------------------
764-80
Average HGL Depth Attained (ft)---------------------------------------
8-8
Time of Max HGL Occurrence (days hh:mm)--------------------
0 12-34
Total Exfiltration Volume (1000-ft3)------------------------------------
0-000
Total Flooded Volume (ac-in) -
0
Total Time Flooded (min)
0
Total Retention Time (sec) -------------------------------------------------
0-00
Page 16

Post -Development 002 - Year
Page 17
Storage Node : Pond-03
Input Data
Invert Elevation (ft)-------------------------------------------------------------
756-00
Max (Rim) Elevation (ft)------------------------------------------------------
770-00
Max (Rim) Offset (ft)-----------------------------------------------------------
14-00
Initial Water Elevation (ft)---------------------------------------------------
764-00
Initial Water Depth (ft)--------------------------------------------------------
8-00
Ponded Area (ft) ----------------------------------------------------------------
0-00
Evaporation Loss----------------------------------------------------------------
0-00
Outflow Weirs
SN Element Weir Flap Crest Crest
ID Type Gate Elevation Offset
(ft) (ft)
1 ESW-02 Trapezoidal No 768-71 12-71
Output Summary Results
Peak Inflow (cfs)-----------------------------------------------------------------
7524
Peak Lateral Inflow (cfs)-----------------------------------------------------
7524
Peak Outflow (cfs)--------------------------------------------------------------
55-15
Peak Exfiltration Flow Rate (cfm)---------------------------------------
0-00
Max HGL Elevation Attained (ft)-----------------------------------------
766-75
Max HGL Depth Attained (ft)----------------------------------------------
10-75
Average HGL Elevation Attained (ft)----------------------------------
764-80
Average HGL Depth Attained (ft)---------------------------------------
8-8
Time of Max HGL Occurrence (days hh:mm)--------------------
0 12-34
Total Exfiltration Volume (1000-ft3)------------------------------------
0-000
Total Flooded Volume (ac-in) -
0
Total Time Flooded (min)
0
Total Retention Time (sec) -------------------------------------------------
0-00
Length Weir Total Discharge
Height Coefficient
(ft) (ft)
70-00 1-30 3-33

Post -Development 002 - Year Page 18
Storage Node : Pond-04
Input Data
Invert Elevation (ft)-------------------------------------------------------------
759-00
Max (Rim) Elevation (ft)------------------------------------------------------
770-00
Max (Rim) Offset (ft)-----------------------------------------------------------
11-00
Initial Water Elevation (ft)---------------------------------------------------
764-00
Initial Water Depth (ft)--------------------------------------------------------
5-00
Ponded Area (ftt)----------------------------------------------------------------
0-00
Evaporation Loss----------------------------------------------------------------
0-00
Output Summary Results
Peak Inflow (cfs)-----------------------------------------------------------------
3327
Peak Lateral Inflow (cfs)-----------------------------------------------------
0-00
Peak Outflow (cfs)--------------------------------------------------------------
1-07
Peak Exfiltration Flow Rate (cfm)---------------------------------------
0-00
Max HGL Elevation Attained (ft)-----------------------------------------
766-75
Max HGL Depth Attained (ft)----------------------------------------------
7-75
Average HGL Elevation Attained (ft)----------------------------------
764-79
Average HGL Depth Attained (ft)---------------------------------------
5-79
Time of Max HGL Occurrence (days hh:mm)--------------------
0 12-36
Total Exfiltration Volume (1000-ft3)------------------------------------
0-000
Total Flooded Volume (ac-in) -
0
Total Time Flooded (min)
0
Total Retention Time (sec) -------------------------------------------------
0-00

Post -Development 010 - Year Page 1
Project Description
File Name .................................................... 29101.0000 - Post Development.SPF
Project Options
Flow Units ---------------------------------------------------
CFS
Elevation Type
Elevation
Hydrology Method .
SCS TR-55
Time of Concentration (TOC) Method --------
SCS TR-55
Link Routing Method
Hydrodynamic
Enable Overflow Ponding at Nodes ------------
YES
Skip Steady State Analysis Time Periods ---
NO
Analysis Options
Start Analysis On .
Mar 30, 2021
00:00:00
End Analysis On .
Apr 04, 2021
00:00:00
Start Reporting On .
Mar 30, 2021
00:00:00
Antecedent Dry Days
0
days
Runoff (Dry Weather) Time Step ----------------
0 01:00:00
days hh:mm:ss
Runoff (Wet Weather) Time Step ---------------
0 00:05:00
days hh:mm:ss
Reporting Time Step -----------------------------------
0 00:05:00
days hh:mm:ss
Routing Time Step --------------------------------------
10
seconds
Number of Elements
Qty
Rain Gages
1
Subbasins
2
Nodes
S
Junctions
2
Outfalls
2
Flow Diversions
0
Inlets
0
Storage Nodes
4
Links
10
Channels
1
Pipes
4
Pumps
0
Orifices
2
Weirs
3
Outlets
0
Pollutants
0
Land Uses
0
Rainfall Details
SN Rain Gage Data Data Source Rainfall Rain State County Return Rainfall Rainfall
ID Source ID Type Units Period Depth Distribution
(years) (inches)
1 Time Series TS-010 Intensity inches North Carolina Rowan 10 5.10 SCS Type II 247hr

Post -Development 010 - Year Page 2
Subbasin Summary
SN Subbasin Area Peak Rate Weighted
ID Factor Curve
Number
Total Total Total Peak Time of
Rainfall Runoff Runoff Runoff Concentration
Volume
(ac) (in) (in) (ac-in) (cfs) (days hh:mm:ss)
1 Sub-01 1916.484.00 90.73 5.10 4.05 77.60 113.90 0 00-06-00
2 Sub-02 2006.484.00 90.81 5.10 4.06 81.42 119.41 0 00-06-00

Post -Development 010 - Year Page 3
Node Summary
SN Element Element
Invert Ground/Rim
Initial Surcharge Ponded
Peak Max HGL
Max
Min
Time of
Total Total Time
ID Type
Elevation
(Max)
Water
Elevation
Area
Inflow
Elevation Surcharge Freeboard
Peak Flooded
Flooded
Elevation Elevation
Attained
Depth
Attained
Flooding
Volume
Attained
Occurrence
(ft)
(ft)
(ft)
(ft)
(ft')
(cfs)
(ft)
(ft)
(ft) (days hh:mm)
(ac-in)
(min)
1 CS-01 Junction
761.50
770.00
761.50
999.00
0.00
35.87
763.47
0.00
10.88
0 00:00
0.00
0.00
2 Jun-01 Junction
760.50
772.00
760.50
999.00
0.00
35.87
761.37
0.00
13.14
0 00:00
0.00
0.00
3 Out-01 Outfall
760.40
35.87
760.58
4 Out-02 Outfall
768.00
0.00
768.00
5 Pond-01 Storage Node
759.00
770.00
764.00
0.00
16.61
767.89
0.00
0.00
6 Pond-02 Storage Node
756.00
770.00
764.00
0.00
144.95
767.89
0.00
0.00
7 Pond-03 Storage Node
756.00
770.00
764.00
0.00
118.52
767.95
0.00
0.00
8 Pond-04 Storage Node
759.00
770.00
764.00
0.00
49.00
767.95
0.00
0.00

Post -Development 010 - Year
Page 4
Link Summary
SN Element Element From To (Outlet) Length Inlet Outlet Average Diameter or Manning's Peak Design Flow Peak Flow/ Peak Flow Peak Flow Peak Flow Total Time Reported
ID Type (Inlet) Node Invert Invert Slope Height Roughness Flow Capacity Design Flow Velocity Depth Depth/ Surcharged Condition
Node Elevation Elevation Ratio Total Depth
Ratio
(ft)
(ft)
(ft)
( % )
(in)
(cfs)
(cfs)
(ft/sec)
(ft)
(min)
1 Pipe_01
Pipe
CS-01 Jun-01
68.00
761.50
760.50
1.4700
36.000
0.0130 35.87
80.88
0.44
10.89
1.42
0.47
0.00 Calculated
2 Pipe01-Overflow
Pipe
Pond-02 Pond-01
50.00
764.00
763.90
02000
36.000
0.0150 16.61
51.70
0.32
1.18
3.00
1.00
127.00 SURCHARGED
3 Pipe-02-Overflow
Pipe
Pond-03 Pond-04
50.00
764.00
763.90
02000
36.000
0.0150 49.00
51.70
0.95
3.47
3.00
1.00
129.00 SURCHARGED
4 Pipe-WQ
Pipe
Pond-03 Pond-02
300.00
756.00
756.10
-0.0300
54.000
0.0150 34.76
31.12
1.12
2.19
4.50
1.00
7200.00 SURCHARGED
5 DummyLink_CHNL-01 Channel
Jun-01 Out-01
50.00
760.50
760.40
02000
24.000
0.0010 35.87
1685.90
0.02
6.89
0.52
026
0.00
6 TOBox-01
Orifice
Pond-02 CS-01
756.00
761.50
60.000
0.00
7 WQ-01
Orifice
Pond-02 CS-01
756.00
761.50
5.000
129
8 ESW-01
Weir
Pond-02 Jun-01
756.00
760.50
0.00
9 ESW-02
Weir
Pond-03 Out-02
756.00
768.00
0.00
10 Weir-01
Weir
Pond-02 CS-01
756.00
761.50
34.58

Post -Development 010 - Year
Subbasin Hydrology
Page 5
Subbasin : Sub-01
Input Data
Area(ac)------------------------------------------------------------------------
1916.
Peak Rate Factor-----------------------------------------------------------
484.00
Weighted Curve Number-----------------------------------------------
90.73
Rain Gage ID .
Rain Gage-001
Composite Curve Number
Area
Soil
Curve
Soil/Surface Description
(acres)
Group
Number
Paved parking & roofs
14.14
C
98.00
> 75 % grass cover, Good
1.45
B
61.00
> 75 % grass cover, Good
3.57
C
74.00
Composite Area & Weighted CN
1916.
90.73
Time of Concentration
TOC Method : SCS TR-55
Sheet Flow Equation :
Tc = (0.007 * ((n * Lf)^0.8)) / ((P^0.5) * (Sf^0.4))
Where :
Tc =
Time of Concentration (hr)
n =
Manning's roughness
Lf =
Flow Length (ft)
P =
2 yr, 24 hr Rainfall (inches)
Sf =
Slope (ft/ft)
Shallow Concentrated Flow Equation :
V = 16.1345 * (Sf^0.5) (unpaved surface)
V = 20.3282 * (Sf^0.5) (paved surface)
V = 15.0 * (Sf^0.5) (grassed waterway surface)
V = 10.0 * (Sf^0.5) (nearly bare & untilled surface)
V = 9.0 * (Sf^0.5) (cultivated straight rows surface)
V = 7.0 * (Sf^0.5) (short grass pasture surface)
V = 5.0 * (Sf^0.5) (woodland surface)
V = 2.5 * (Sf^0.5) (forest w/heavy litter surface)
Tc = (Lf / V) / (3600 sec/hr)
Where
Tc = Time of Concentration (hr)
Lf = Flow Length (ft)
V = Velocity (ft/sec)
Sf = Slope (ft/ft)
Channel Flow Equation:
V = (1.49 * (R^(2/3)) * (Sf^0.5)) / n
R =Aq/Wp
Tc = (Lf / V) / (3600 sec/hr)
Where :
Tc =
Time of Concentration (hr)
Lf =
Flow Length (ft)
R =
Hydraulic Radius (ft)
Aq =
Flow Area (ft)
Wp
= Wetted Perimeter (ft)
V =
Velocity (ft/sec)
Sf =
Slope (ft/ft)
n =
Manning's roughness
User -Defined TOC override (minutes): 6
Subbasin Runoff Results
Total Rainfall (in)------------------------------------------------------------ 5.10
Total Runoff (in)------------------------------------------------------------- 4.05
Peak Runoff (cfs)----------------------------------------------------------- 113.90
Weighted Curve Number----------------------------------------------- 90.73
Time of Concentration (days hh:mm:ss)------------------------ 0 00-06-00

Post -Development 010 - Year Page 6
Subbasin : Sub-01
7.5
7
6.5
6
5.5
5
4.5
4
3.5
M
F 3
2.5
2
1.5
1
0.5
120
115
110
106
100
95
90
85
80
75
70
N
65
u 60
0
55
1h 50
45
40
35
30
25
20
15
10
5
Rainfall Intensity Graph
Time [hrs]
Runoff Hydrograph
0 6 10 15 20 25 30 35 40 45 50 55 60 65 70 76 80 85 90 95 100 105 110 115
Time [hrs]

Post -Development 010 - Year
Subbasin : Sub-02
Page 7
Input Data
Area(ac)------------------------------------------------------------------------ 20-06
Peak Rate Factor----------------------------------------------------------- 484-00
Weighted Curve Number----------------------------------------------- 90-81
Rain Gage ID----------------------------------------------------------------- Rain Gage-001
Composite Curve Number
Area
Soil
Curve
Soil/Surface Description
(acres)
Group
Number
Paved parking & roofs
15-11
A
98-00
> 75 % grass cover, Good
1-95
B
61-00
> 75 % grass cover, Good
3-00
C
74-00
Composite Area & Weighted CN
20-06
90-81
Time of Concentration
User -Defined TOC override (minutes): 6
Subbasin Runoff Results
Total Rainfall (in)------------------------------------------------------------ 5-10
Total Runoff (in)------------------------------------------------------------- 4-06
Peak Runoff (cfs)----------------------------------------------------------- 119-41
Weighted Curve Number----------------------------------------------- 90-81
Time of Concentration (days hh:mm:ss)------------------------ 0 00-06-00

Post -Development 010 - Year Page 8
Subbasin : Sub-02
7.5
7
6.5
6
5.5
5
4.5
4
3.5
3
2.5
2
1.5
1
0.5
125
120
115
110
105
100
95
90
85
80
75
N 70
65
60
55
50
45
40
35
30
25
20
15
10
5
Rainfall Intensity Graph
Time [hrs]
Runoff Hydrograph
0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 105 110 115
Time [hrs]

Post -Development 010 - Year Page 9
Channel Input
SN Element Length Inlet Inlet
Outlet Outlet Total Average Shape
Height Width Manning's Entrance Exit/Bend Additional Initial
ID Invert Invert
Invert Invert Drop
Slope
Roughness Losses Losses Losses Flow
Elevation Offset Elevation Offset
(ft) (ft) (ft)
(ft) (ft) (ft)
( % )
(ft) (ft) (cfs)
1 DummyLin"HNL-01 50.00 760.50 0.00
760.40 0.00 0.10
02000 Rectangular
2000.10.000 0.0010 0.5000 0.5000 0.0000 0.00

Post -Development 010 - Year Page 11
Channel Results
SN Element Peak Time of Design Flow Peak Flow/ Peak Flow Travel Peak Flow Peak Flow Total Time Froude Reported
ID Flow Peak Flow Capacity Design Flow Velocity Time Depth Depth/ Surcharged Number Condition
Occurrence Ratio Total Depth
Ratio
(cfs) (days hh:mm) (cfs) (ft/sec) (min) (ft) (min)
1 DummyLink_CHNL-01 35.87 0 12:18 1685.90 0.02 6.89 0.12 0.52 026 0.00

Post -Development 010 - Year Page 12
Pipe Input
SN Element
Length
Inlet
Inlet
Outlet Outlet Total Average Pipe
Pipe Pipe
Manning's Entrance Exit/Bend Additional Initial Flap
ID
Invert
Invert
Invert Invert Drop
Slope Shape
Diameteror Width
Roughness
Losses
Losses
Losses Flow Gate
Elevation Offset Elevation Offset
Height
(ft)
(ft)
(ft)
(ft) (ft) (ft)
( % )
(in) (in)
(cfs)
1 Pipe_01
68.00
761.50
0.00
760.50 0.00 1.00
1.4700 CIRCULAR
36.000 36.000
0.0130
0.5000
0.5000
0.0000 0.00 No
2 Pipe01-Overflow
50.00
764.00
8.00
763.90 4.90 0.10
02000 CIRCULAR
36.000 36.000
0.0150
0.5000
0.5000
0.0000 0.00 No
3 Pipe-02-Overflow
50.00
764.00
8.00
763.90 4.90 0.10
02000 CIRCULAR
36.000 36.000
0.0150
0.5000
0.5000
0.0000 0.00 No
4 Pipe-WQ
300.00
756.00
0.00
756.10 0.10 -0.10
-0.0300 CIRCULAR
54.000 54.000
0.0150
0.5000
0.5000
0.0000 0.00 No

Post -Development 010 - Year Page 14
Pipe Results
SN Element
Peak
Time of Design Flow
Peak Flow/ Peak Flow Travel Peak Flow
Peak Flow
Total Time
Froude Reported
ID
Flow
Peak Flow
Capacity
Design Flow
Velocity Time
Depth
Depth/
Surcharged
Number Condition
Occurrence
Ratio
Total Depth
Ratio
(cfs) (days hh:mm)
(cfs)
(ft/sec) (min)
(ft)
(min)
1 Pipe_01
35.87
0 12:18
80.88
0.44
10.89 0.10
1.42
0.47
0.00
Calculated
2 Pipe01-Overflow
16.61
0 12:00
51.70
0.32
1.18 0.71
3.00
1.00
127.00
SURCHARGED
3 Pipe-02-Overflow
49.00
0 12:00
51.70
0.95
3.47 024
3.00
1.00
129.00
SURCHARGED
4 Pipe-WQ
34.76
0 12:02
31.12
1.12
2.19 228
4.50
1.00
7200.00
SURCHARGED

Post -Development 010 - Year Page 15
Storage Nodes
Storage Node : Pond-01
Input Data
Invert Elevation (ft)-------------------------------------------------------------
759-00
Max (Rim) Elevation (ft)------------------------------------------------------
770-00
Max (Rim) Offset (ft)-----------------------------------------------------------
11-00
Initial Water Elevation (ft)---------------------------------------------------
764-00
Initial Water Depth (ft)--------------------------------------------------------
5-00
Ponded Area (ftt)----------------------------------------------------------------
0-00
Evaporation Loss----------------------------------------------------------------
0-00
Output Summary Results
Peak Inflow (cfs)-----------------------------------------------------------------
16-61
Peak Lateral Inflow (cfs)-----------------------------------------------------
0-00
Peak Outflow (cfs)--------------------------------------------------------------
1-33
Peak Exfiltration Flow Rate (cfm)---------------------------------------
0-00
Max HGL Elevation Attained (ft)-----------------------------------------
767-89
Max HGL Depth Attained (ft)----------------------------------------------
8-89
Average HGL Elevation Attained (ft)----------------------------------
764-95
Average HGL Depth Attained (ft)---------------------------------------
5-95
Time of Max HGL Occurrence (days hh:mm)--------------------
0 12-18
Total Exfiltration Volume (1000-ft3)------------------------------------
0-000
Total Flooded Volume (ac-in) -
0
Total Time Flooded (min)
0
Total Retention Time (sec) -------------------------------------------------
0-00

Post -Development
010 - Year
Storage Node : Pond-02
Input Data
Invert Elevation (ft)-------------------------------------------------------------
756-00
Max (Rim) Elevation (ft)------------------------------------------------------
770-00
Max (Rim) Offset (ft)-----------------------------------------------------------
14-00
Initial Water Elevation (ft)---------------------------------------------------
764-00
Initial Water Depth (ft)--------------------------------------------------------
8-00
Ponded Area (ft) ----------------------------------------------------------------
0-00
Evaporation Loss----------------------------------------------------------------
0-00
Outflow Weirs
SN Element
Weir Flap
Crest
Crest
Length
Weir Total Discharge
ID
Type Gate
Elevation
Offset
Height Coefficient
(ft)
(ft)
(ft)
(ft)
1 ESW-01
Trapezoidal No
768-71
12-71
60-00
1-30 3-33
2 Weir-01
Rectangular No
765-60
9-60
3-00
325 3-33
Outflow Orifices
SN Element Orifice
Orifice
Flap
Circular Rectangular Rectangular
Orifice Orifice
ID Type
Shape
Gate
Orifice
Orifice
Orifice
Invert Coefficient
Diameter
Height
Width
Elevation
(in)
(in)
(in)
(ft)
1 TOBox-01 Bottom
Rectangular No
60-00
60-00
768-85 0-63
2 WQ-01 Side
CIRCULAR
No
5-00
764-00 0-61
Output Summary Results
Peak Inflow (cfs)-----------------------------------------------------------------
144-95
Peak Lateral Inflow (cfs)-----------------------------------------------------
113-04
Peak Outflow (cfs)--------------------------------------------------------------
40-88
Peak Exfiltration Flow Rate (cfm)---------------------------------------
0-00
Max HGL Elevation Attained (ft)-----------------------------------------
767-89
Max HGL Depth Attained (ft)----------------------------------------------
11-89
Average HGL Elevation Attained (ft)----------------------------------
764-95
Average HGL Depth Attained (ft)---------------------------------------
8-95
Time of Max HGL Occurrence (days hh:mm)--------------------
0 12-18
Total Exfiltration Volume (1000-ft3)------------------------------------
0-000
Total Flooded Volume (ac-in) -
0
Total Time Flooded (min)
0
Total Retention Time (sec) -------------------------------------------------
0-00
Page 16

Post -Development 010 - Year
Page 17
Storage Node : Pond-03
Input Data
Invert Elevation (ft)-------------------------------------------------------------
756-00
Max (Rim) Elevation (ft)------------------------------------------------------
770-00
Max (Rim) Offset (ft)-----------------------------------------------------------
14-00
Initial Water Elevation (ft)---------------------------------------------------
764-00
Initial Water Depth (ft)--------------------------------------------------------
8-00
Ponded Area (ft) ----------------------------------------------------------------
0-00
Evaporation Loss----------------------------------------------------------------
0-00
Outflow Weirs
SN Element Weir Flap Crest Crest
ID Type Gate Elevation Offset
(ft) (ft)
1 ESW-02 Trapezoidal No 768-71 12-71
Output Summary Results
Peak Inflow (cfs)-----------------------------------------------------------------
118-52
Peak Lateral Inflow (cfs)-----------------------------------------------------
118-52
Peak Outflow (cfs)--------------------------------------------------------------
83-09
Peak Exfiltration Flow Rate (cfm)---------------------------------------
0-00
Max HGL Elevation Attained (ft)-----------------------------------------
767-95
Max HGL Depth Attained (ft)----------------------------------------------
11-95
Average HGL Elevation Attained (ft)----------------------------------
764-95
Average HGL Depth Attained (ft)---------------------------------------
8-95
Time of Max HGL Occurrence (days hh:mm)--------------------
0 12-16
Total Exfiltration Volume (1000-ft3)------------------------------------
0-000
Total Flooded Volume (ac-in) -
0
Total Time Flooded (min)
0
Total Retention Time (sec) -------------------------------------------------
0-00
Length Weir Total Discharge
Height Coefficient
(ft) (ft)
70-00 1-30 3-33

Post -Development 010 - Year Page 18
Storage Node : Pond-04
Input Data
Invert Elevation (ft)-------------------------------------------------------------
759-00
Max (Rim) Elevation (ft)------------------------------------------------------
770-00
Max (Rim) Offset (ft)-----------------------------------------------------------
11-00
Initial Water Elevation (ft)---------------------------------------------------
764-00
Initial Water Depth (ft)--------------------------------------------------------
5-00
Ponded Area (ftt)----------------------------------------------------------------
0-00
Evaporation Loss----------------------------------------------------------------
0-00
Output Summary Results
Peak Inflow (cfs)-----------------------------------------------------------------
49-00
Peak Lateral Inflow (cfs)-----------------------------------------------------
0-00
Peak Outflow (cfs)--------------------------------------------------------------
3-92
Peak Exfiltration Flow Rate (cfm)---------------------------------------
0-00
Max HGL Elevation Attained (ft)-----------------------------------------
767-95
Max HGL Depth Attained (ft)----------------------------------------------
8-95
Average HGL Elevation Attained (ft)----------------------------------
764-95
Average HGL Depth Attained (ft)---------------------------------------
5-95
Time of Max HGL Occurrence (days hh:mm)--------------------
0 12-15
Total Exfiltration Volume (1000-ft3)------------------------------------
0-000
Total Flooded Volume (ac-in) -
0
Total Time Flooded (min)
0
Total Retention Time (sec) -------------------------------------------------
0-00

Post -Development 025 - Year Page 1
Project Description
File Name .................................................... 29101.0000 - Post Development.SPF
Project Options
Flow Units ---------------------------------------------------
CFS
Elevation Type
Elevation
Hydrology Method .
SCS TR-55
Time of Concentration (TOC) Method --------
SCS TR-55
Link Routing Method
Hydrodynamic
Enable Overflow Ponding at Nodes ------------
YES
Skip Steady State Analysis Time Periods ---
NO
Analysis Options
Start Analysis On .
Mar 30, 2021
00:00:00
End Analysis On .
Apr 04, 2021
00:00:00
Start Reporting On .
Mar 30, 2021
00:00:00
Antecedent Dry Days
0
days
Runoff (Dry Weather) Time Step ----------------
0 01:00:00
days hh:mm:ss
Runoff (Wet Weather) Time Step ---------------
0 00:05:00
days hh:mm:ss
Reporting Time Step -----------------------------------
0 00:05:00
days hh:mm:ss
Routing Time Step --------------------------------------
10
seconds
Number of Elements
Qty
Rain Gages
1
Subbasins
2
Nodes
S
Junctions
2
Outfalls
2
Flow Diversions
0
Inlets
0
Storage Nodes
4
Links
10
Channels
1
Pipes
4
Pumps
0
Orifices
2
Weirs
3
Outlets
0
Pollutants
0
Land Uses
0
Rainfall Details
SN Rain Gage Data Data Source Rainfall Rain State County Return Rainfall Rainfall
ID Source ID Type Units Period Depth Distribution
(years) (inches)
1 Time Series TS-025 Intensity inches North Carolina Rowan 25 6.00 SCS Type II 247hr

Post -Development 025 - Year Page 2
Subbasin Summary
SN Subbasin Area Peak Rate Weighted
ID Factor Curve
Number
Total Total Total Peak Time of
Rainfall Runoff Runoff Runoff Concentration
Volume
(ac) (in) (in) (ac-in) (cfs) (days hh:mm:ss)
1 Sub-01 1916.484.00 90.73 6.00 4.93 94.40 137.02 0 00-06-00
2 Sub-02 2006.484.00 90.81 6.00 4.94 99.02 143.58 0 00-06-00

Post -Development 025 - Year Page 3
Node Summary
SN Element Element
Invert Ground/Rim
Initial Surcharge Ponded
Peak Max HGL
Max
Min
Time of
Total Total Time
ID Type
Elevation
(Max)
Water
Elevation
Area
Inflow
Elevation Surcharge Freeboard
Peak Flooded
Flooded
Elevation Elevation
Attained
Depth
Attained
Flooding
Volume
Attained
Occurrence
(ft)
(ft)
(ft)
(ft)
(ft2)
(cfs)
(ft)
(ft)
(ft) (days hh:mm)
(ac-in)
(min)
1 CS-01 Junction
761.50
770.00
761.50
999.00
0.00
5022
763.98
0.00
10.37
0 00:00
0.00
0.00
2 Jun-01 Junction
760.50
772.00
760.50
999.00
0.00
5022
761.60
0.00
12.91
0 00:00
0.00
0.00
3 Out-01 Outfall
760.40
5023
760.62
4 Out-02 Outfall
768.00
0.00
768.00
5 Pond-01 Storage Node
759.00
770.00
764.00
0.00
1980.
768.48
0.00
0.00
6 Pond-02 Storage Node
756.00
770.00
764.00
0.00
175.46
768.48
0.00
0.00
7 Pond-03 Storage Node
756.00
770.00
764.00
0.00
142.60
768.60
0.00
0.00
8 Pond-04 Storage Node
759.00
770.00
764.00
0.00
56.68
768.60
0.00
0.00

Post -Development 025 - Year
Page 4
Link Summary
SN Element Element From To (Outlet) Length Inlet Outlet Average Diameter or Manning's Peak Design Flow Peak Flow/ Peak Flow Peak Flow Peak Flow Total Time Reported
ID Type (Inlet) Node Invert Invert Slope Height Roughness Flow Capacity Design Flow Velocity Depth Depth/ Surcharged Condition
Node Elevation Elevation Ratio Total Depth
Ratio
(ft)
(ft)
(ft)
( % )
(in)
(cfs)
(cfs)
(ft/sec)
(ft)
(min)
1 Pipe_01
Pipe
CS-01 Jun-01
68.00
761.50
760.50
1.4700
36.000
0.0130 5022
80.88
0.62
11.42
1.79
0.60
0.00 Calculated
2 Pipe01-Overflow
Pipe
Pond-02 Pond-01
50.00
764.00
763.90
02000
36.000
0.0150 1980.
51.70
0.38
1.40
3.00
1.00
163.00 SURCHARGED
3 Pipe-02-Overflow
Pipe
Pond-03 Pond-04
50.00
764.00
763.90
02000
36.000
0.0150 56.68
51.70
1.10
4.01
3.00
1.00
165.00 SURCHARGED
4 Pipe-WQ
Pipe
Pond-03 Pond-02
300.00
756.00
756.10
-0.0300
54.000
0.0150 43.35
31.12
1.39
2.73
4.50
1.00
7200.00 SURCHARGED
5 DummyLink_CHNL-01 Channel
Jun-01 Out-01
50.00
760.50
760.40
02000
24.000
0.0010 5023
1685.90
0.03
7.62
0.66
0.33
0.00
6 TOBox-01
Orifice
Pond-02 CS-01
756.00
761.50
60.000
0.00
7 WQ-01
Orifice
Pond-02 CS-01
756.00
761.50
5.000
1.39
8 ESW-01
Weir
Pond-02 Jun-01
756.00
760.50
0.00
9 ESW-02
Weir
Pond-03 Out-02
756.00
768.00
0.00
10 Weir-01
Weir
Pond-02 CS-01
756.00
761.50
48.84

Post -Development 025 - Year
Subbasin Hydrology
Page 5
Subbasin : Sub-01
Input Data
Area(ac)------------------------------------------------------------------------
1916.
Peak Rate Factor-----------------------------------------------------------
484.00
Weighted Curve Number-----------------------------------------------
90.73
Rain Gage ID .
Rain Gage-001
Composite Curve Number
Area
Soil
Curve
Soil/Surface Description
(acres)
Group
Number
Paved parking & roofs
14.14
C
98.00
> 75 % grass cover, Good
1.45
B
61.00
> 75 % grass cover, Good
3.57
C
74.00
Composite Area & Weighted CN
1916.
90.73
Time of Concentration
TOC Method : SCS TR-55
Sheet Flow Equation :
Tc = (0.007 * ((n * Lf)^0.8)) / ((P^0.5) * (Sf^0.4))
Where :
Tc =
Time of Concentration (hr)
n =
Manning's roughness
Lf =
Flow Length (ft)
P =
2 yr, 24 hr Rainfall (inches)
Sf =
Slope (ft/ft)
Shallow Concentrated Flow Equation :
V = 16.1345 * (Sf^0.5) (unpaved surface)
V = 20.3282 * (Sf^0.5) (paved surface)
V = 15.0 * (Sf^0.5) (grassed waterway surface)
V = 10.0 * (Sf^0.5) (nearly bare & untilled surface)
V = 9.0 * (Sf^0.5) (cultivated straight rows surface)
V = 7.0 * (Sf^0.5) (short grass pasture surface)
V = 5.0 * (Sf^0.5) (woodland surface)
V = 2.5 * (Sf^0.5) (forest w/heavy litter surface)
Tc = (Lf / V) / (3600 sec/hr)
Where
Tc = Time of Concentration (hr)
Lf = Flow Length (ft)
V = Velocity (ft/sec)
Sf = Slope (ft/ft)
Channel Flow Equation:
V = (1.49 * (R^(2/3)) * (Sf^0.5)) / n
R =Aq/Wp
Tc = (Lf / V) / (3600 sec/hr)
Where :
Tc =
Time of Concentration (hr)
Lf =
Flow Length (ft)
R =
Hydraulic Radius (ft)
Aq =
Flow Area (ft)
Wp
= Wetted Perimeter (ft)
V =
Velocity (ft/sec)
Sf =
Slope (ft/ft)
n =
Manning's roughness
User -Defined TOC override (minutes): 6
Subbasin Runoff Results
Total Rainfall (in)------------------------------------------------------------ 6.00
Total Runoff (in)------------------------------------------------------------- 4.93
Peak Runoff (cfs)----------------------------------------------------------- 137.02
Weighted Curve Number----------------------------------------------- 90.73
Time of Concentration (days hh:mm:ss)------------------------ 0 00-06-00

Post -Development 025 - Year Page 6
Subbasin : Sub-01
8.5
8
7.5
7
65
6
5.5
5
u 4.5
4
3.6
3
2.6
2
1.5
1
0.5
145
140
135
130
125
120
115
110
105
100
95
90
_ 85
N 80
75
0 70
65
60
55
50
45
40
35
30
25
20
15
10
5
Rainfall Intensity Graph
Time [hrs]
Runoff Hydrograph
0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 105 110 115
Time [hrs]

Post -Development 025 - Year
Subbasin : Sub-02
Page 7
Input Data
Area(ac)------------------------------------------------------------------------ 20-06
Peak Rate Factor----------------------------------------------------------- 484-00
Weighted Curve Number----------------------------------------------- 90-81
Rain Gage ID----------------------------------------------------------------- Rain Gage-001
Composite Curve Number
Area
Soil
Curve
Soil/Surface Description
(acres)
Group
Number
Paved parking & roofs
15-11
A
98-00
> 75 % grass cover, Good
1-95
B
61-00
> 75 % grass cover, Good
3-00
C
74-00
Composite Area & Weighted CN
20-06
90-81
Time of Concentration
User -Defined TOC override (minutes): 6
Subbasin Runoff Results
Total Rainfall (in)------------------------------------------------------------
6-00
Total Runoff (in)-------------------------------------------------------------
4-94
Peak Runoff (cfs)-----------------------------------------------------------
143-58
Weighted Curve Number-----------------------------------------------
90-81
Time of Concentration (days hh:mm:ss)------------------------
0 00-06-00

Post -Development 025 - Year Page 8
Subbasin : Sub-02
9
8.5
8
7.5
7
6.5
6
5.5
5
4.5
M
4
8
3.5
3
2.5
2
1.5
1
0.5
155
150
145
140
135
130
125
120
115
110
105
100
95
90
85
80
0 75
� 70
1h 65
60
55
50
45
40
35
30
25
20
15
10
5
Rainfall Intensity Graph
Time [hrs]
Runoff Hydrograph
0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 105 110 115
Time [hrs]

Post -Development 025 - Year Page 9
Channel Input
SN Element Length Inlet Inlet
Outlet Outlet Total Average Shape
Height Width Manning's Entrance Exit/Bend Additional Initial
ID Invert Invert
Invert Invert Drop
Slope
Roughness Losses Losses Losses Flow
Elevation Offset Elevation Offset
(ft) (ft) (ft)
(ft) (ft) (ft)
( % )
(ft) (ft) (cfs)
1 DummyLin"HNL-01 50.00 760.50 0.00
760.40 0.00 0.10
02000 Rectangular
2000.10.000 0.0010 0.5000 0.5000 0.0000 0.00

Post -Development 025 - Year Page 11
Channel Results
SN Element Peak Time of Design Flow Peak Flow/ Peak Flow Travel Peak Flow Peak Flow Total Time Froude Reported
ID Flow Peak Flow Capacity Design Flow Velocity Time Depth Depth/ Surcharged Number Condition
Occurrence Ratio Total Depth
Ratio
(cfs) (days hh:mm) (cfs) (ft/sec) (min) (ft) (min)
1 DummyLink_CHNL-01 5023 0 12:15 1685.90 0.03 7.62 0.11 0.66 0.33 0.00

Post -Development 025 - Year Page 12
Pipe Input
SN Element
Length
Inlet
Inlet
Outlet Outlet Total Average Pipe
Pipe Pipe
Manning's Entrance Exit/Bend Additional Initial Flap
ID
Invert
Invert
Invert Invert Drop
Slope Shape
Diameteror Width
Roughness
Losses
Losses
Losses Flow Gate
Elevation Offset Elevation Offset
Height
(ft)
(ft)
(ft)
(ft) (ft) (ft)
( % )
(in) (in)
(cfs)
1 Pipe_01
68.00
761.50
0.00
760.50 0.00 1.00
1.4700 CIRCULAR
36.000 36.000
0.0130
0.5000
0.5000
0.0000 0.00 No
2 Pipe01-Overflow
50.00
764.00
8.00
763.90 4.90 0.10
02000 CIRCULAR
36.000 36.000
0.0150
0.5000
0.5000
0.0000 0.00 No
3 Pipe-02-Overflow
50.00
764.00
8.00
763.90 4.90 0.10
02000 CIRCULAR
36.000 36.000
0.0150
0.5000
0.5000
0.0000 0.00 No
4 Pipe-WQ
300.00
756.00
0.00
756.10 0.10 -0.10
-0.0300 CIRCULAR
54.000 54.000
0.0150
0.5000
0.5000
0.0000 0.00 No

Post -Development 025 - Year Page 14
Pipe Results
SN Element
Peak
Time of Design Flow
Peak Flow/ Peak Flow Travel Peak Flow
Peak Flow
Total Time
Froude Reported
ID
Flow
Peak Flow
Capacity
Design Flow
Velocity Time
Depth
Depth/
Surcharged
Number Condition
Occurrence
Ratio
Total Depth
Ratio
(cfs) (days hh:mm)
(cfs)
(ft/sec) (min)
(ft)
(min)
1 Pipe_01
5022
0 12:15
80.88
0.62
11.42 0.10
1.79
0.60
0.00
Calculated
2 Pipe01-Overflow
1980.
0 12:00
51.70
0.38
1.40 0.60
3.00
1.00
163.00
SURCHARGED
3 Pipe-02-Overflow
56.68
0 12:01
51.70
1.10
4.01 021
3.00
1.00
165.00
SURCHARGED
4 Pipe-WQ
43.35
0 12:02
31.12
1.39
2.73 1.83
4.50
1.00
7200.00
SURCHARGED

Post -Development 025 - Year Page 15
Storage Nodes
Storage Node : Pond-01
Input Data
Invert Elevation (ft)-------------------------------------------------------------
759-00
Max (Rim) Elevation (ft)------------------------------------------------------
770-00
Max (Rim) Offset (ft)-----------------------------------------------------------
11-00
Initial Water Elevation (ft)---------------------------------------------------
764-00
Initial Water Depth (ft)--------------------------------------------------------
5-00
Ponded Area (ftt)----------------------------------------------------------------
0-00
Evaporation Loss----------------------------------------------------------------
0-00
Output Summary Results
Peak Inflow (cfs)-----------------------------------------------------------------
19-80
Peak Lateral Inflow (cfs)-----------------------------------------------------
0-00
Peak Outflow (cfs)--------------------------------------------------------------
1-97
Peak Exfiltration Flow Rate (cfm)---------------------------------------
0-00
Max HGL Elevation Attained (ft)-----------------------------------------
768-48
Max HGL Depth Attained (ft)----------------------------------------------
9-48
Average HGL Elevation Attained (ft)----------------------------------
765-03
Average HGL Depth Attained (ft)---------------------------------------
6-03
Time of Max HGL Occurrence (days hh:mm)--------------------
0 12-15
Total Exfiltration Volume (1000-ft3)------------------------------------
0-000
Total Flooded Volume (ac-in) -
0
Total Time Flooded (min)
0
Total Retention Time (sec) -------------------------------------------------
0-00

Post -Development
025 - Year
Storage Node : Pond-02
Input Data
Invert Elevation (ft)-------------------------------------------------------------
756-00
Max (Rim) Elevation (ft)------------------------------------------------------
770-00
Max (Rim) Offset (ft)-----------------------------------------------------------
14-00
Initial Water Elevation (ft)---------------------------------------------------
764-00
Initial Water Depth (ft)--------------------------------------------------------
8-00
Ponded Area (ft) ----------------------------------------------------------------
0-00
Evaporation Loss----------------------------------------------------------------
0-00
Outflow Weirs
SN Element
Weir Flap
Crest
Crest
Length
Weir Total Discharge
ID
Type Gate
Elevation
Offset
Height Coefficient
(ft)
(ft)
(ft)
(ft)
1 ESW-01
Trapezoidal No
768-71
12-71
60-00
1-30 3-33
2 Weir-01
Rectangular No
765-60
9-60
3-00
325 3-33
Outflow Orifices
SN Element Orifice
Orifice
Flap
Circular Rectangular Rectangular
Orifice Orifice
ID Type
Shape
Gate
Orifice
Orifice
Orifice
Invert Coefficient
Diameter
Height
Width
Elevation
(in)
(in)
(in)
(ft)
1 TOBox-01 Bottom
Rectangular No
60-00
60-00
768-85 0-63
2 WQ-01 Side
CIRCULAR
No
5-00
764-00 0-61
Output Summary Results
Peak Inflow (cfs)-----------------------------------------------------------------
175-46
Peak Lateral Inflow (cfs)-----------------------------------------------------
135-86
Peak Outflow (cfs)--------------------------------------------------------------
56-68
Peak Exfiltration Flow Rate (cfm)---------------------------------------
0-00
Max HGL Elevation Attained (ft)-----------------------------------------
768-48
Max HGL Depth Attained (ft)----------------------------------------------
12-48
Average HGL Elevation Attained (ft)----------------------------------
765-03
Average HGL Depth Attained (ft)---------------------------------------
9-03
Time of Max HGL Occurrence (days hh:mm)--------------------
0 12-14
Total Exfiltration Volume (1000-ft3)------------------------------------
0-000
Total Flooded Volume (ac-in) -
0
Total Time Flooded (min)
0
Total Retention Time (sec) -------------------------------------------------
0-00
Page 16

Post -Development 025 - Year
Page 17
Storage Node : Pond-03
Input Data
Invert Elevation (ft)-------------------------------------------------------------
756.00
Max (Rim) Elevation (ft)------------------------------------------------------
770.00
Max (Rim) Offset (ft)-----------------------------------------------------------
14.00
Initial Water Elevation (ft)---------------------------------------------------
764.00
Initial Water Depth (ft)--------------------------------------------------------
8.00
Ponded Area (ft) ----------------------------------------------------------------
0.00
Evaporation Loss----------------------------------------------------------------
0.00
Outflow Weirs
SN Element Weir Flap Crest Crest
ID Type Gate Elevation Offset
(ft) (ft)
1 ESW-02 Trapezoidal No 768.71 12.71
Output Summary Results
Peak Inflow (cfs)-----------------------------------------------------------------
142.60
Peak Lateral Inflow (cfs)-----------------------------------------------------
142.60
Peak Outflow (cfs)--------------------------------------------------------------
99.68
Peak Exfiltration Flow Rate (cfm)---------------------------------------
0.00
Max HGL Elevation Attained (ft)-----------------------------------------
768.60
Max HGL Depth Attained (ft)----------------------------------------------
12.6
Average HGL Elevation Attained (ft)----------------------------------
765.03
Average HGL Depth Attained (ft)---------------------------------------
9.03
Time of Max HGL Occurrence (days hh:mm)--------------------
0 12-16
Total Exfiltration Volume (1000-ft3)------------------------------------
0.000
Total Flooded Volume (ac-in) .
0
Total Time Flooded (min)
0
Total Retention Time (sec) -------------------------------------------------
0.00
Length Weir Total Discharge
Height Coefficient
(ft) (ft)
70.00 1.30 3.33

Post -Development 025 - Year Page 18
Storage Node : Pond-04
Input Data
Invert Elevation (ft)-------------------------------------------------------------
759-00
Max (Rim) Elevation (ft)------------------------------------------------------
770-00
Max (Rim) Offset (ft)-----------------------------------------------------------
11-00
Initial Water Elevation (ft)---------------------------------------------------
764-00
Initial Water Depth (ft)--------------------------------------------------------
5-00
Ponded Area (ftt)----------------------------------------------------------------
0-00
Evaporation Loss----------------------------------------------------------------
0-00
Output Summary Results
Peak Inflow (cfs)-----------------------------------------------------------------
56-68
Peak Lateral Inflow (cfs)-----------------------------------------------------
0-00
Peak Outflow (cfs)--------------------------------------------------------------
6-10
Peak Exfiltration Flow Rate (cfm)---------------------------------------
0-00
Max HGL Elevation Attained (ft)-----------------------------------------
768-60
Max HGL Depth Attained (ft)----------------------------------------------
9-6
Average HGL Elevation Attained (ft)----------------------------------
765-03
Average HGL Depth Attained (ft)---------------------------------------
6-03
Time of Max HGL Occurrence (days hh:mm)--------------------
0 12-14
Total Exfiltration Volume (1000-ft3)------------------------------------
0-000
Total Flooded Volume (ac-in) -
0
Total Time Flooded (min)
0
Total Retention Time (sec) -------------------------------------------------
0-00

Post -Development 050 - Year Page 1
Project Description
File Name .................................................... 29101.0000 - Post Development.SPF
Project Options
Flow Units ---------------------------------------------------
CFS
Elevation Type
Elevation
Hydrology Method .
SCS TR-55
Time of Concentration (TOC) Method --------
SCS TR-55
Link Routing Method
Hydrodynamic
Enable Overflow Ponding at Nodes ------------
YES
Skip Steady State Analysis Time Periods ---
NO
Analysis Options
Start Analysis On .
Mar 30, 2021
00:00:00
End Analysis On .
Apr 04, 2021
00:00:00
Start Reporting On .
Mar 30, 2021
00:00:00
Antecedent Dry Days
0
days
Runoff (Dry Weather) Time Step ----------------
0 01:00:00
days hh:mm:ss
Runoff (Wet Weather) Time Step ---------------
0 00:05:00
days hh:mm:ss
Reporting Time Step -----------------------------------
0 00:05:00
days hh:mm:ss
Routing Time Step --------------------------------------
10
seconds
Number of Elements
Qty
Rain Gages
1
Subbasins
2
Nodes
S
Junctions
2
Outfalls
2
Flow Diversions
0
Inlets
0
Storage Nodes
4
Links
10
Channels
1
Pipes
4
Pumps
0
Orifices
2
Weirs
3
Outlets
0
Pollutants
0
Land Uses
0
Rainfall Details
SN Rain Gage Data Data Source Rainfall Rain State County Return Rainfall Rainfall
ID Source ID Type Units Period Depth Distribution
(years) (inches)
1 Time Series TS-050 Intensity inches North Carolina Rowan 50 6.50 SCS Type II 247hr

Post -Development 050 - Year Page 2
Subbasin Summary
SN Subbasin Area Peak Rate Weighted
ID Factor Curve
Number
Total Total Total Peak Time of
Rainfall Runoff Runoff Runoff Concentration
Volume
(ac) (in) (in) (ac-in) (cfs) (days hh:mm:ss)
1 Sub-01 1916.484.00 90.73 6.50 5.42 103.79 149.84 0 00-06-00
2 Sub-02 2006.484.00 90.81 6.50 5.43 108.85 156.95 0 00-06-00

Post -Development 050 - Year Page 3
Node Summary
SN Element Element
Invert Ground/Rim
Initial Surcharge Ponded
Peak Max HGL
Max
Min
Time of
Total Total Time
ID Type
Elevation
(Max)
Water
Elevation
Area
Inflow
Elevation Surcharge Freeboard
Peak Flooded
Flooded
Elevation Elevation
Attained
Depth
Attained
Flooding
Volume
Attained
Occurrence
(ft)
(ft)
(ft)
(ft)
(ft')
(cfs)
(ft)
(ft)
(ft) (days hh:mm)
(ac-in)
(min)
1 CS-01 Junction
761.50
770.00
761.50
999.00
0.00
57.42
76425
0.00
10.10
0 00:00
0.00
0.00
2 Jun-01 Junction
760.50
772.00
760.50
999.00
0.00
59.36
761.74
0.00
12.77
0 00:00
0.00
0.00
3 Out-01 Outfall
760.40
59.37
760.64
4 Out-02 Outfall
768.00
13.60
768.00
5 Pond-01 Storage Node
759.00
770.00
764.00
0.00
21.50
768.76
0.00
0.00
6 Pond-02 Storage Node
756.00
770.00
764.00
0.00
192.34
768.76
0.00
0.00
7 Pond-03 Storage Node
756.00
770.00
764.00
0.00
155.97
768.86
0.00
0.00
8 Pond-04 Storage Node
759.00
770.00
764.00
0.00
6122
768.87
0.00
0.00

Post -Development 050 - Year
Page 4
Link Summary
SN Element Element From To (Outlet) Length Inlet Outlet Average Diameter or Manning's Peak Design Flow Peak Flow/ Peak Flow Peak Flow Peak Flow Total Time Reported
ID Type (Inlet) Node Invert Invert Slope Height Roughness Flow Capacity Design Flow Velocity Depth Depth/ Surcharged Condition
Node Elevation Elevation Ratio Total Depth
Ratio
(ft)
(ft)
(ft)
( % )
(in)
(cfs)
(cfs)
(ft/sec)
(ft)
(min)
1 Pipe_01
Pipe
CS-01 Jun-01
68.00
761.50
760.50
1.4700
36.000
0.0130 57.42
80.88
0.71
11.54
1.99
0.67
0.00 Calculated
2 Pipe01-Overflow
Pipe
Pond-02 Pond-01
50.00
764.00
763.90
02000
36.000
0.0150 21.50
51.70
0.42
1.52
3.00
1.00
177.00 SURCHARGED
3 Pipe-02-Overflow
Pipe
Pond-03 Pond-04
50.00
764.00
763.90
02000
36.000
0.0150 6122
51.70
1.18
4.33
3.00
1.00
179.00 SURCHARGED
4 Pipe-WQ
Pipe
Pond-03 Pond-02
300.00
756.00
756.10
-0.0300
54.000
0.0150 47.72
31.12
1.53
3.00
4.50
1.00
7200.00 SURCHARGED
5 DummyLink_CHNL-01 Channel
Jun-01 Out-01
50.00
760.50
760.40
02000
24.000
0.0010 59.37
1685.90
0.04
8.03
0.74
0.37
0.00
6 TOBox-01
Orifice
Pond-02 CS-01
756.00
761.50
60.000
0.00
7 WQ-01
Orifice
Pond-02 CS-01
756.00
761.50
5.000
1.43
8 ESW-01
Weir
Pond-02 Jun-01
756.00
760.50
1.94
9 ESW-02
Weir
Pond-03 Out-02
756.00
768.00
13.60
10 Weir-01
Weir
Pond-02 CS-01
756.00
761.50
56.00

Post -Development 050 - Year
Subbasin Hydrology
Page 5
Subbasin : Sub-01
Input Data
Area(ac)------------------------------------------------------------------------
1916.
Peak Rate Factor-----------------------------------------------------------
484.00
Weighted Curve Number-----------------------------------------------
90.73
Rain Gage ID .
Rain Gage-001
Composite Curve Number
Area
Soil
Curve
Soil/Surface Description
(acres)
Group
Number
Paved parking & roofs
14.14
C
98.00
> 75 % grass cover, Good
1.45
B
61.00
> 75 % grass cover, Good
3.57
C
74.00
Composite Area & Weighted CN
1916.
90.73
Time of Concentration
TOC Method : SCS TR-55
Sheet Flow Equation :
Tc = (0.007 * ((n * Lf)^0.8)) / ((P^0.5) * (Sf^0.4))
Where :
Tc =
Time of Concentration (hr)
n =
Manning's roughness
Lf =
Flow Length (ft)
P =
2 yr, 24 hr Rainfall (inches)
Sf =
Slope (ft/ft)
Shallow Concentrated Flow Equation :
V = 16.1345 * (Sf^0.5) (unpaved surface)
V = 20.3282 * (Sf^0.5) (paved surface)
V = 15.0 * (Sf^0.5) (grassed waterway surface)
V = 10.0 * (Sf^0.5) (nearly bare & untilled surface)
V = 9.0 * (Sf^0.5) (cultivated straight rows surface)
V = 7.0 * (Sf^0.5) (short grass pasture surface)
V = 5.0 * (Sf^0.5) (woodland surface)
V = 2.5 * (Sf^0.5) (forest w/heavy litter surface)
Tc = (Lf / V) / (3600 sec/hr)
Where
Tc = Time of Concentration (hr)
Lf = Flow Length (ft)
V = Velocity (ft/sec)
Sf = Slope (ft/ft)
Channel Flow Equation:
V = (1.49 * (R^(2/3)) * (Sf^0.5)) / n
R =Aq/Wp
Tc = (Lf / V) / (3600 sec/hr)
Where :
Tc =
Time of Concentration (hr)
Lf =
Flow Length (ft)
R =
Hydraulic Radius (ft)
Aq =
Flow Area (ft)
Wp
= Wetted Perimeter (ft)
V =
Velocity (ft/sec)
Sf =
Slope (ft/ft)
n =
Manning's roughness
User -Defined TOC override (minutes): 6
Subbasin Runoff Results
Total Rainfall (in)------------------------------------------------------------ 6.50
Total Runoff (in)------------------------------------------------------------- 5.42
Peak Runoff (cfs)----------------------------------------------------------- 149.84
Weighted Curve Number----------------------------------------------- 90.73
Time of Concentration (days hh:mm:ss)------------------------ 0 00-06-00

Post -Development 050 - Year Page 6
Subbasin : Sub-01
9
8.5
8
7.5
7
6.5
6
5.5
5
4.5
M
4
8
3.5
3
2.5
2
1.5
1
0.5
155
150
145
140
135
130
125
120
115
110
105
100
95
90
85
80
0 75
� 70
1h 65
60
55
50
45
40
35
30
25
20
15
10
5
Rainfall Intensity Graph
Time [hrs]
Runoff Hydrograph
0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 105 110 115
Time [hrs]

Post -Development 050 - Year
Subbasin : Sub-02
Page 7
Input Data
Area(ac)------------------------------------------------------------------------ 20-06
Peak Rate Factor----------------------------------------------------------- 484-00
Weighted Curve Number----------------------------------------------- 90-81
Rain Gage ID----------------------------------------------------------------- Rain Gage-001
Composite Curve Number
Area
Soil
Curve
Soil/Surface Description
(acres)
Group
Number
Paved parking & roofs
15-11
A
98-00
> 75 % grass cover, Good
1-95
B
61-00
> 75 % grass cover, Good
3-00
C
74-00
Composite Area & Weighted CN
20-06
90-81
Time of Concentration
User -Defined TOC override (minutes): 6
Subbasin Runoff Results
Total Rainfall (in)------------------------------------------------------------
6-50
Total Runoff (in)-------------------------------------------------------------
5-43
Peak Runoff (cfs)-----------------------------------------------------------
156-95
Weighted Curve Number-----------------------------------------------
90-81
Time of Concentration (days hh:mm:ss)------------------------
0 00-06-00

Post -Development 050 - Year Page 8
Subbasin : Sub-02
9.5
9
8.5
8
7.5
7
6.5
6
5.5
u 5
° 4.5
4
3.5
3
2.5
2
1.5
1
0.5
170
160
150
140
130
120
110
_ 100
N
90
80
70
60
50
40
30
20
10
Rainfall Intensity Graph
Time [hrs]
Runoff Hydrograph
0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 105 110 115
Time [hrs]

Post -Development 050 - Year Page 9
Channel Input
SN Element Length Inlet Inlet
Outlet Outlet Total Average Shape
Height Width Manning's Entrance Exit/Bend Additional Initial
ID Invert Invert
Invert Invert Drop
Slope
Roughness Losses Losses Losses Flow
Elevation Offset Elevation Offset
(ft) (ft) (ft)
(ft) (ft) (ft)
( % )
(ft) (ft) (cfs)
1 DummyLin"HNL-01 50.00 760.50 0.00
760.40 0.00 0.10
02000 Rectangular
2000.10.000 0.0010 0.5000 0.5000 0.0000 0.00

Post -Development 050 - Year Page 11
Channel Results
SN Element Peak Time of Design Flow Peak Flow/ Peak Flow Travel Peak Flow Peak Flow Total Time Froude Reported
ID Flow Peak Flow Capacity Design Flow Velocity Time Depth Depth/ Surcharged Number Condition
Occurrence Ratio Total Depth
Ratio
(cfs) (days hh:mm) (cfs) (ft/sec) (min) (ft) (min)
1 DummyLink_CHNL-01 59.37 0 12:13 1685.90 0.04 8.03 0.10 0.74 0.37 0.00

Post -Development 050 - Year Page 12
Pipe Input
SN Element
Length
Inlet
Inlet
Outlet Outlet Total Average Pipe
Pipe Pipe
Manning's Entrance Exit/Bend Additional Initial Flap
ID
Invert
Invert
Invert Invert Drop
Slope Shape
Diameteror Width
Roughness
Losses
Losses
Losses Flow Gate
Elevation Offset Elevation Offset
Height
(ft)
(ft)
(ft)
(ft) (ft) (ft)
( % )
(in) (in)
(cfs)
1 Pipe_01
68.00
761.50
0.00
760.50 0.00 1.00
1.4700 CIRCULAR
36.000 36.000
0.0130
0.5000
0.5000
0.0000 0.00 No
2 Pipe01-Overflow
50.00
764.00
8.00
763.90 4.90 0.10
02000 CIRCULAR
36.000 36.000
0.0150
0.5000
0.5000
0.0000 0.00 No
3 Pipe-02-Overflow
50.00
764.00
8.00
763.90 4.90 0.10
02000 CIRCULAR
36.000 36.000
0.0150
0.5000
0.5000
0.0000 0.00 No
4 Pipe-WQ
300.00
756.00
0.00
756.10 0.10 -0.10
-0.0300 CIRCULAR
54.000 54.000
0.0150
0.5000
0.5000
0.0000 0.00 No

Post -Development 050 - Year Page 14
Pipe Results
SN Element
Peak
Time of Design Flow
Peak Flow/ Peak Flow Travel Peak Flow
Peak Flow
Total Time
Froude Reported
ID
Flow
Peak Flow
Capacity
Design Flow
Velocity Time
Depth
Depth/
Surcharged
Number Condition
Occurrence
Ratio
Total Depth
Ratio
(cfs) (days hh:mm)
(cfs)
(ft/sec) (min)
(ft)
(min)
1 Pipe_01
57.42
0 12:13
80.88
0.71
11.54 0.10
1.99
0.67
0.00
Calculated
2 Pipe01-Overflow
21.50
0 12:00
51.70
0.42
1.52 0.55
3.00
1.00
177.00
SURCHARGED
3 Pipe-02-Overflow
6122
0 12:01
51.70
1.18
4.33 0.19
3.00
1.00
179.00
SURCHARGED
4 Pipe-WQ
47.72
0 12:02
31.12
1.53
3.00 1.67
4.50
1.00
7200.00
SURCHARGED

Post -Development 050 - Year Page 15
Storage Nodes
Storage Node : Pond-01
Input Data
Invert Elevation (ft)-------------------------------------------------------------
759-00
Max (Rim) Elevation (ft)------------------------------------------------------
770-00
Max (Rim) Offset (ft)-----------------------------------------------------------
11-00
Initial Water Elevation (ft)---------------------------------------------------
764-00
Initial Water Depth (ft)--------------------------------------------------------
5-00
Ponded Area (ftt)----------------------------------------------------------------
0-00
Evaporation Loss----------------------------------------------------------------
0-00
Output Summary Results
Peak Inflow (cfs)-----------------------------------------------------------------
21-50
Peak Lateral Inflow (cfs)-----------------------------------------------------
0-00
Peak Outflow (cfs)--------------------------------------------------------------
220
Peak Exfiltration Flow Rate (cfm)---------------------------------------
0-00
Max HGL Elevation Attained (ft)-----------------------------------------
768-76
Max HGL Depth Attained (ft)----------------------------------------------
9-76
Average HGL Elevation Attained (ft)----------------------------------
765-06
Average HGL Depth Attained (ft)---------------------------------------
6-06
Time of Max HGL Occurrence (days hh:mm)--------------------
0 12-13
Total Exfiltration Volume (1000-ft3)------------------------------------
0-000
Total Flooded Volume (ac-in) -
0
Total Time Flooded (min)
0
Total Retention Time (sec) -------------------------------------------------
0-00

Post -Development
050 - Year
Storage Node : Pond-02
Input Data
Invert Elevation (ft)-------------------------------------------------------------
756-00
Max (Rim) Elevation (ft)------------------------------------------------------
770-00
Max (Rim) Offset (ft)-----------------------------------------------------------
14-00
Initial Water Elevation (ft)---------------------------------------------------
764-00
Initial Water Depth (ft)--------------------------------------------------------
8-00
Ponded Area (ft) ----------------------------------------------------------------
0-00
Evaporation Loss----------------------------------------------------------------
0-00
Outflow Weirs
SN Element
Weir Flap
Crest
Crest
Length
Weir Total Discharge
ID
Type Gate
Elevation
Offset
Height Coefficient
(ft)
(ft)
(ft)
(ft)
1 ESW-01
Trapezoidal No
768-71
12-71
60-00
1-30 3-33
2 Weir-01
Rectangular No
765-60
9-60
3-00
325 3-33
Outflow Orifices
SN Element Orifice
Orifice
Flap
Circular Rectangular Rectangular
Orifice Orifice
ID Type
Shape
Gate
Orifice
Orifice
Orifice
Invert Coefficient
Diameter
Height
Width
Elevation
(in)
(in)
(in)
(ft)
1 TOBox-01 Bottom
Rectangular No
60-00
60-00
768-85 0-63
2 WQ-01 Side
CIRCULAR
No
5-00
764-00 0-61
Output Summary Results
Peak Inflow (cfs)-----------------------------------------------------------------
192-34
Peak Lateral Inflow (cfs)-----------------------------------------------------
148-73
Peak Outflow (cfs)--------------------------------------------------------------
65-44
Peak Exfiltration Flow Rate (cfm)---------------------------------------
0-00
Max HGL Elevation Attained (ft)-----------------------------------------
768-76
Max HGL Depth Attained (ft)----------------------------------------------
12-76
Average HGL Elevation Attained (ft)----------------------------------
765-07
Average HGL Depth Attained (ft)---------------------------------------
9-07
Time of Max HGL Occurrence (days hh:mm)--------------------
0 12-13
Total Exfiltration Volume (1000-ft3)------------------------------------
0-000
Total Flooded Volume (ac-in) -
0
Total Time Flooded (min)
0
Total Retention Time (sec) -------------------------------------------------
0-00
Page 16

Post -Development 050 - Year
Page 17
Storage Node : Pond-03
Input Data
Invert Elevation (ft)-------------------------------------------------------------
756-00
Max (Rim) Elevation (ft)------------------------------------------------------
770-00
Max (Rim) Offset (ft)-----------------------------------------------------------
14-00
Initial Water Elevation (ft)---------------------------------------------------
764-00
Initial Water Depth (ft)--------------------------------------------------------
8-00
Ponded Area (ft) ----------------------------------------------------------------
0-00
Evaporation Loss----------------------------------------------------------------
0-00
Outflow Weirs
SN Element Weir Flap Crest Crest
ID Type Gate Elevation Offset
(ft) (ft)
1 ESW-02 Trapezoidal No 768-71 12-71
Output Summary Results
Peak Inflow (cfs)-----------------------------------------------------------------
155-97
Peak Lateral Inflow (cfs)-----------------------------------------------------
155-97
Peak Outflow (cfs)--------------------------------------------------------------
108-60
Peak Exfiltration Flow Rate (cfm)---------------------------------------
0-00
Max HGL Elevation Attained (ft)-----------------------------------------
768-86
Max HGL Depth Attained (ft)----------------------------------------------
12-86
Average HGL Elevation Attained (ft)----------------------------------
765-07
Average HGL Depth Attained (ft)---------------------------------------
9-07
Time of Max HGL Occurrence (days hh:mm)--------------------
0 12-12
Total Exfiltration Volume (1000-ft3)------------------------------------
0-000
Total Flooded Volume (ac-in) -
0
Total Time Flooded (min)
0
Total Retention Time (sec) -------------------------------------------------
0-00
Length Weir Total Discharge
Height Coefficient
(ft) (ft)
70-00 1-30 3-33

Post -Development 050 - Year Page 18
Storage Node : Pond-04
Input Data
Invert Elevation (ft)-------------------------------------------------------------
759-00
Max (Rim) Elevation (ft)------------------------------------------------------
770-00
Max (Rim) Offset (ft)-----------------------------------------------------------
11-00
Initial Water Elevation (ft)---------------------------------------------------
764-00
Initial Water Depth (ft)--------------------------------------------------------
5-00
Ponded Area (ftt)----------------------------------------------------------------
0-00
Evaporation Loss----------------------------------------------------------------
0-00
Output Summary Results
Peak Inflow (cfs)-----------------------------------------------------------------
6122
Peak Lateral Inflow (cfs)-----------------------------------------------------
0-00
Peak Outflow (cfs)--------------------------------------------------------------
6-90
Peak Exfiltration Flow Rate (cfm)---------------------------------------
0-00
Max HGL Elevation Attained (ft)-----------------------------------------
768-87
Max HGL Depth Attained (ft)----------------------------------------------
9-87
Average HGL Elevation Attained (ft)----------------------------------
765-07
Average HGL Depth Attained (ft)---------------------------------------
6-07
Time of Max HGL Occurrence (days hh:mm)--------------------
0 12-13
Total Exfiltration Volume (1000-ft3)------------------------------------
0-000
Total Flooded Volume (ac-in) -
0
Total Time Flooded (min)
0
Total Retention Time (sec) -------------------------------------------------
0-00

Post -Development 100 - Year Page 1
Project Description
File Name .................................................... 29101.0000 - Post Development.SPF
Project Options
Flow Units ---------------------------------------------------
CFS
Elevation Type
Elevation
Hydrology Method .
SCS TR-55
Time of Concentration (TOC) Method --------
SCS TR-55
Link Routing Method
Hydrodynamic
Enable Overflow Ponding at Nodes ------------
YES
Skip Steady State Analysis Time Periods ---
NO
Analysis Options
Start Analysis On .
Mar 30, 2021
00:00:00
End Analysis On .
Apr 04, 2021
00:00:00
Start Reporting On .
Mar 30, 2021
00:00:00
Antecedent Dry Days
0
days
Runoff (Dry Weather) Time Step ----------------
0 01:00:00
days hh:mm:ss
Runoff (Wet Weather) Time Step ---------------
0 00:05:00
days hh:mm:ss
Reporting Time Step -----------------------------------
0 00:05:00
days hh:mm:ss
Routing Time Step --------------------------------------
10
seconds
Number of Elements
Qty
Rain Gages
1
Subbasins
2
Nodes
S
Junctions
2
Outfalls
2
Flow Diversions
0
Inlets
0
Storage Nodes
4
Links
10
Channels
1
Pipes
4
Pumps
0
Orifices
2
Weirs
3
Outlets
0
Pollutants
0
Land Uses
0
Rainfall Details
SN Rain Gage Data Data Source Rainfall Rain State County Return Rainfall Rainfall
ID Source ID Type Units Period Depth Distribution
(years) (inches)
1 Time Series TS-100 Intensity inches North Carolina Rowan 100 720 SCS Type II 247

Post -Development 100 - Year Page 2
Subbasin Summary
SN Subbasin Area Peak Rate Weighted
ID Factor Curve
Number
Total Total Total Peak Time of
Rainfall Runoff Runoff Runoff Concentration
Volume
(ac) (in) (in) (ac-in) (cfs) (days hh:mm:ss)
1 Sub-01 1916.484.00 90.73 720 6.10 116.95 167.57 0 00-06-00
2 Sub-02 2006.484.00 90.81 720 6.11 122.63 175.61 0 00-06-00

Post -Development 100 - Year Page 3
Node Summary
SN Element Element
Invert Ground/Rim
Initial Surcharge Ponded
Peak Max HGL
Max
Min
Time of
Total Total Time
ID Type
Elevation
(Max)
Water
Elevation
Area
Inflow
Elevation Surcharge Freeboard
Peak Flooded
Flooded
Elevation Elevation
Attained
Depth
Attained
Flooding
Volume
Attained
Occurrence
(ft)
(ft)
(ft)
(ft)
(ft')
(cfs)
(ft)
(ft)
(ft) (days hh:mm)
(ac-in)
(min)
1 CS-01 Junction
761.50
770.00
761.50
999.00
0.00
64.79
764.73
0.00
9.62
0 00:00
0.00
0.00
2 Jun-01 Junction
760.50
772.00
760.50
999.00
0.00
91.34
762.18
0.00
12.33
0 00:00
0.00
0.00
3 Out-01 Outfall
760.40
91.35
760.71
4 Out-02 Outfall
768.00
43.68
768.00
5 Pond-01 Storage Node
759.00
770.00
764.00
0.00
23.77
768.97
0.00
0.00
6 Pond-02 Storage Node
756.00
770.00
764.00
0.00
21521
768.97
0.00
0.00
7 Pond-03 Storage Node
756.00
770.00
764.00
0.00
174.53
769.04
0.00
0.00
8 Pond-04 Storage Node
759.00
770.00
764.00
0.00
67.60
769.05
0.00
0.00

Post -Development 100 - Year
Page 4
Link Summary
SN Element Element From To (Outlet) Length Inlet Outlet Average Diameter or Manning's Peak Design Flow Peak Flow/ Peak Flow Peak Flow Peak Flow Total Time Reported
ID Type (Inlet) Node Invert Invert Slope Height Roughness Flow Capacity Design Flow Velocity Depth Depth/ Surcharged Condition
Node Elevation Elevation Ratio Total Depth
Ratio
(ft)
(ft)
(ft)
( % )
(in)
(cfs)
(cfs)
(ft/sec)
(ft)
(min)
1 Pipe_01
Pipe
CS-01 Jun-01
68.00
761.50
760.50
1.4700
36.000
0.0130 64.79
80.88
0.80
11.54
2.34
0.78
0.00 Calculated
2 Pipe01-Overflow
Pipe
Pond-02 Pond-01
50.00
764.00
763.90
02000
36.000
0.0150 23.77
51.70
0.46
1.68
3.00
1.00
191.00 SURCHARGED
3 Pipe-02-Overflow
Pipe
Pond-03 Pond-04
50.00
764.00
763.90
02000
36.000
0.0150 67.60
51.70
1.31
4.78
3.00
1.00
193.00 SURCHARGED
4 Pipe-WQ
Pipe
Pond-03 Pond-02
300.00
756.00
756.10
-0.0300
54.000
0.0150 53.19
31.12
1.71
3.34
4.50
1.00
7200.00 SURCHARGED
5 DummyLink_CHNL-01 Channel
Jun-01 Out-01
50.00
760.50
760.40
02000
24.000
0.0010 91.35
1685.90
0.05
9.17
1.00
0.50
0.00
6 TOBox-01
Orifice
Pond-02 CS-01
756.00
761.50
60.000
2.76
7 WQ-01
Orifice
Pond-02 CS-01
756.00
761.50
5.000
1.43
8 ESW-01
Weir
Pond-02 Jun-01
756.00
760.50
26.55
9 ESW-02
Weir
Pond-03 Out-02
756.00
768.00
43.68
10 Weir-01
Weir
Pond-02 CS-01
756.00
761.50
60.65

Post -Development 100 - Year
Subbasin Hydrology
Page 5
Subbasin : Sub-01
Input Data
Area(ac)------------------------------------------------------------------------
1916.
Peak Rate Factor-----------------------------------------------------------
484.00
Weighted Curve Number-----------------------------------------------
90.73
Rain Gage ID .
Rain Gage-001
Composite Curve Number
Area
Soil
Curve
Soil/Surface Description
(acres)
Group
Number
Paved parking & roofs
14.14
C
98.00
> 75 % grass cover, Good
1.45
B
61.00
> 75 % grass cover, Good
3.57
C
74.00
Composite Area & Weighted CN
1916.
90.73
Time of Concentration
TOC Method : SCS TR-55
Sheet Flow Equation :
Tc = (0.007 * ((n * Lf)^0.8)) / ((P^0.5) * (Sf^0.4))
Where :
Tc =
Time of Concentration (hr)
n =
Manning's roughness
Lf =
Flow Length (ft)
P =
2 yr, 24 hr Rainfall (inches)
Sf =
Slope (ft/ft)
Shallow Concentrated Flow Equation :
V = 16.1345 * (Sf^0.5) (unpaved surface)
V = 20.3282 * (Sf^0.5) (paved surface)
V = 15.0 * (Sf^0.5) (grassed waterway surface)
V = 10.0 * (Sf^0.5) (nearly bare & untilled surface)
V = 9.0 * (Sf^0.5) (cultivated straight rows surface)
V = 7.0 * (Sf^0.5) (short grass pasture surface)
V = 5.0 * (Sf^0.5) (woodland surface)
V = 2.5 * (Sf^0.5) (forest w/heavy litter surface)
Tc = (Lf / V) / (3600 sec/hr)
Where
Tc = Time of Concentration (hr)
Lf = Flow Length (ft)
V = Velocity (ft/sec)
Sf = Slope (ft/ft)
Channel Flow Equation:
V = (1.49 * (R^(2/3)) * (Sf^0.5)) / n
R =Aq/Wp
Tc = (Lf / V) / (3600 sec/hr)
Where :
Tc =
Time of Concentration (hr)
Lf =
Flow Length (ft)
R =
Hydraulic Radius (ft)
Aq =
Flow Area (ft)
Wp
= Wetted Perimeter (ft)
V =
Velocity (ft/sec)
Sf =
Slope (ft/ft)
n =
Manning's roughness
User -Defined TOC override (minutes): 6
Subbasin Runoff Results
Total Rainfall (in)------------------------------------------------------------ 720
Total Runoff (in)------------------------------------------------------------- 6.10
Peak Runoff (cfs)----------------------------------------------------------- 167.57
Weighted Curve Number----------------------------------------------- 90.73
Time of Concentration (days hh:mm:ss)------------------------ 0 00-06-00

Post -Development 100 - Year Page 6
Subbasin : Sub-01
10
9.5
9
8.5
8
7.5
7
6.5
6
� 5.5
u 5
4.5
4
3.5
3
2.5
2
1.5
1
0.5
180
170
160
150
140
130
120
110
N 100
u 90
0
80
70
60
50
40
30
20
10
Rainfall Intensity Graph
Time [hrs]
Runoff Hydrograph
0 6 10 15 20 25 30 35 40 45 50 55 60 65 70 76 80 85 90 95 100 105 110 115
Time [hrs]

Post -Development 100 - Year
Subbasin : Sub-02
Page 7
Input Data
Area(ac)------------------------------------------------------------------------ 20-06
Peak Rate Factor----------------------------------------------------------- 484-00
Weighted Curve Number----------------------------------------------- 90-81
Rain Gage ID----------------------------------------------------------------- Rain Gage-001
Composite Curve Number
Area
Soil
Curve
Soil/Surface Description
(acres)
Group
Number
Paved parking & roofs
15-11
A
98-00
> 75 % grass cover, Good
1-95
B
61-00
> 75 % grass cover, Good
3-00
C
74-00
Composite Area & Weighted CN
20-06
90-81
Time of Concentration
User -Defined TOC override (minutes): 6
Subbasin Runoff Results
Total Rainfall (in)------------------------------------------------------------ 720
Total Runoff (in)------------------------------------------------------------- 6-11
Peak Runoff (cfs)----------------------------------------------------------- 175-61
Weighted Curve Number----------------------------------------------- 90-81
Time of Concentration (days hh:mm:ss)------------------------ 0 00-06-00

Post -Development 100 - Year Page 8
Subbasin : Sub-02
10.5
10
9.5
9
8.5
8
7.5
7
6.6
� 6
5.5
° 5
4.5
4
3.5
3
2.5
2
1.5
1
0.6
190
180
170
160
150
140
130
120
110
N
100
90
80
70
60
50
40
30
20
10
Rainfall Intensity Graph
Time [hrs]
Runoff Hydrograph
0 6 10 15 20 25 30 35 40 45 50 55 60 65 70 76 80 85 90 95 100 105 110 115
Time [hrs]

Post -Development 100 - Year Page 9
Channel Input
SN Element Length Inlet Inlet
Outlet Outlet Total Average Shape
Height Width Manning's Entrance Exit/Bend Additional Initial
ID Invert Invert
Invert Invert Drop
Slope
Roughness Losses Losses Losses Flow
Elevation Offset Elevation Offset
(ft) (ft) (ft)
(ft) (ft) (ft)
( % )
(ft) (ft) (cfs)
1 DummyLin"HNL-01 50.00 760.50 0.00
760.40 0.00 0.10
02000 Rectangular
2000.10.000 0.0010 0.5000 0.5000 0.0000 0.00

Post -Development 100 - Year Page 11
Channel Results
SN Element Peak Time of Design Flow Peak Flow/ Peak Flow Travel Peak Flow Peak Flow Total Time Froude Reported
ID Flow Peak Flow Capacity Design Flow Velocity Time Depth Depth/ Surcharged Number Condition
Occurrence Ratio Total Depth
Ratio
(cfs) (days hh:mm) (cfs) (ft/sec) (min) (ft) (min)
1 DummyLink_CHNL-01 91.35 0 12:09 1685.90 0.05 9.17 0.09 1.00 0.50 0.00

Post -Development 100 - Year Page 12
Pipe Input
SN Element
Length
Inlet
Inlet
Outlet Outlet Total Average Pipe
Pipe Pipe
Manning's Entrance Exit/Bend Additional Initial Flap
ID
Invert
Invert
Invert Invert Drop
Slope Shape
Diameteror Width
Roughness
Losses
Losses
Losses Flow Gate
Elevation Offset Elevation Offset
Height
(ft)
(ft)
(ft)
(ft) (ft) (ft)
( % )
(in) (in)
(cfs)
1 Pipe_01
68.00
761.50
0.00
760.50 0.00 1.00
1.4700 CIRCULAR
36.000 36.000
0.0130
0.5000
0.5000
0.0000 0.00 No
2 Pipe01-Overflow
50.00
764.00
8.00
763.90 4.90 0.10
02000 CIRCULAR
36.000 36.000
0.0150
0.5000
0.5000
0.0000 0.00 No
3 Pipe-02-Overflow
50.00
764.00
8.00
763.90 4.90 0.10
02000 CIRCULAR
36.000 36.000
0.0150
0.5000
0.5000
0.0000 0.00 No
4 Pipe-WQ
300.00
756.00
0.00
756.10 0.10 -0.10
-0.0300 CIRCULAR
54.000 54.000
0.0150
0.5000
0.5000
0.0000 0.00 No

Post -Development 100 - Year Page 14
Pipe Results
SN Element
Peak
Time of Design Flow
Peak Flow/ Peak Flow Travel Peak Flow
Peak Flow
Total Time
Froude Reported
ID
Flow
Peak Flow
Capacity
Design Flow
Velocity Time
Depth
Depth/
Surcharged
Number Condition
Occurrence
Ratio
Total Depth
Ratio
(cfs) (days hh:mm)
(cfs)
(ft/sec) (min)
(ft)
(min)
1 Pipe_01
64.79
0 12:09
80.88
0.80
11.54 0.10
2.34
0.78
0.00
Calculated
2 Pipe01-Overflow
23.77
0 12:00
51.70
0.46
1.68 0.50
3.00
1.00
191.00
SURCHARGED
3 Pipe-02-Overflow
67.60
0 12:01
51.70
1.31
4.78 0.17
3.00
1.00
193.00
SURCHARGED
4 Pipe-WQ
53.19
0 12:02
31.12
1.71
3.34 1.50
4.50
1.00
7200.00
SURCHARGED

Post -Development 100 - Year Page 15
Storage Nodes
Storage Node : Pond-01
Input Data
Invert Elevation (ft)-------------------------------------------------------------
759-00
Max (Rim) Elevation (ft)------------------------------------------------------
770-00
Max (Rim) Offset (ft)-----------------------------------------------------------
11-00
Initial Water Elevation (ft)---------------------------------------------------
764-00
Initial Water Depth (ft)--------------------------------------------------------
5-00
Ponded Area (ftt)----------------------------------------------------------------
0-00
Evaporation Loss----------------------------------------------------------------
0-00
Output Summary Results
Peak Inflow (cfs)-----------------------------------------------------------------
23-77
Peak Lateral Inflow (cfs)-----------------------------------------------------
0-00
Peak Outflow (cfs)--------------------------------------------------------------
3-92
Peak Exfiltration Flow Rate (cfm)---------------------------------------
0-00
Max HGL Elevation Attained (ft)-----------------------------------------
768-97
Max HGL Depth Attained (ft)----------------------------------------------
9-97
Average HGL Elevation Attained (ft)----------------------------------
765-10
Average HGL Depth Attained (ft)---------------------------------------
6-1
Time of Max HGL Occurrence (days hh:mm)--------------------
0 12-09
Total Exfiltration Volume (1000-ft3)------------------------------------
0-000
Total Flooded Volume (ac-in) -
0
Total Time Flooded (min)
0
Total Retention Time (sec) -------------------------------------------------
0-00

Post -Development
100 - Year
Storage Node : Pond-02
Input Data
Invert Elevation (ft)-------------------------------------------------------------
756-00
Max (Rim) Elevation (ft)------------------------------------------------------
770-00
Max (Rim) Offset (ft)-----------------------------------------------------------
14-00
Initial Water Elevation (ft)---------------------------------------------------
764-00
Initial Water Depth (ft)--------------------------------------------------------
8-00
Ponded Area (ft) ----------------------------------------------------------------
0-00
Evaporation Loss----------------------------------------------------------------
0-00
Outflow Weirs
SN Element
Weir Flap
Crest
Crest
Length
Weir Total Discharge
ID
Type Gate
Elevation
Offset
Height Coefficient
(ft)
(ft)
(ft)
(ft)
1 ESW-01
Trapezoidal No
768-71
12-71
60-00
1-30 3-33
2 Weir-01
Rectangular No
765-60
9-60
3-00
325 3-33
Outflow Orifices
SN Element Orifice
Orifice
Flap
Circular Rectangular Rectangular
Orifice Orifice
ID Type
Shape
Gate
Orifice
Orifice
Orifice
Invert Coefficient
Diameter
Height
Width
Elevation
(in)
(in)
(in)
(ft)
1 TOBox-01 Bottom
Rectangular No
60-00
60-00
768-85 0-63
2 WQ-01 Side
CIRCULAR
No
5-00
764-00 0-61
Output Summary Results
Peak Inflow (cfs)-----------------------------------------------------------------
21521
Peak Lateral Inflow (cfs)-----------------------------------------------------
166-62
Peak Outflow (cfs)--------------------------------------------------------------
92-16
Peak Exfiltration Flow Rate (cfm)---------------------------------------
0-00
Max HGL Elevation Attained (ft)-----------------------------------------
768-97
Max HGL Depth Attained (ft)----------------------------------------------
12-97
Average HGL Elevation Attained (ft)----------------------------------
765-10
Average HGL Depth Attained (ft)---------------------------------------
9-1
Time of Max HGL Occurrence (days hh:mm)--------------------
0 12-09
Total Exfiltration Volume (1000-ft3)------------------------------------
0-000
Total Flooded Volume (ac-in) -
0
Total Time Flooded (min)
0
Total Retention Time (sec) -------------------------------------------------
0-00
Page 16

Post -Development 100 - Year
Page 17
Storage Node : Pond-03
Input Data
Invert Elevation (ft)-------------------------------------------------------------
756-00
Max (Rim) Elevation (ft)------------------------------------------------------
770-00
Max (Rim) Offset (ft)-----------------------------------------------------------
14-00
Initial Water Elevation (ft)---------------------------------------------------
764-00
Initial Water Depth (ft)--------------------------------------------------------
8-00
Ponded Area (ft) ----------------------------------------------------------------
0-00
Evaporation Loss----------------------------------------------------------------
0-00
Outflow Weirs
SN Element Weir Flap Crest Crest
ID Type Gate Elevation Offset
(ft) (ft)
1 ESW-02 Trapezoidal No 768-71 12-71
Output Summary Results
Peak Inflow (cfs)-----------------------------------------------------------------
174-53
Peak Lateral Inflow (cfs)-----------------------------------------------------
174-53
Peak Outflow (cfs)--------------------------------------------------------------
136-43
Peak Exfiltration Flow Rate (cfm)---------------------------------------
0-00
Max HGL Elevation Attained (ft)-----------------------------------------
769-04
Max HGL Depth Attained (ft)----------------------------------------------
13-04
Average HGL Elevation Attained (ft)----------------------------------
765-11
Average HGL Depth Attained (ft)---------------------------------------
9-11
Time of Max HGL Occurrence (days hh:mm)--------------------
0 12-07
Total Exfiltration Volume (1000-ft3)------------------------------------
0-000
Total Flooded Volume (ac-in) -
0
Total Time Flooded (min)
0
Total Retention Time (sec) -------------------------------------------------
0-00
Length Weir Total Discharge
Height Coefficient
(ft) (ft)
70-00 1-30 3-33

Post -Development 100 - Year Page 18
Storage Node : Pond-04
Input Data
Invert Elevation (ft)-------------------------------------------------------------
759-00
Max (Rim) Elevation (ft)------------------------------------------------------
770-00
Max (Rim) Offset (ft)-----------------------------------------------------------
11-00
Initial Water Elevation (ft)---------------------------------------------------
764-00
Initial Water Depth (ft)--------------------------------------------------------
5-00
Ponded Area (ftt)----------------------------------------------------------------
0-00
Evaporation Loss----------------------------------------------------------------
0-00
Output Summary Results
Peak Inflow (cfs)-----------------------------------------------------------------
67-60
Peak Lateral Inflow (cfs)-----------------------------------------------------
0-00
Peak Outflow (cfs)--------------------------------------------------------------
11-44
Peak Exfiltration Flow Rate (cfm)---------------------------------------
0-00
Max HGL Elevation Attained (ft)-----------------------------------------
769-05
Max HGL Depth Attained (ft)----------------------------------------------
10-05
Average HGL Elevation Attained (ft)----------------------------------
765-11
Average HGL Depth Attained (ft)---------------------------------------
6-11
Time of Max HGL Occurrence (days hh:mm)--------------------
0 12-10
Total Exfiltration Volume (1000-ft3)------------------------------------
0-000
Total Flooded Volume (ac-in) -
0
Total Time Flooded (min)
0
Total Retention Time (sec) -------------------------------------------------
0-00

STORMWATER MANAGEMENT REPORT
1-85 COMMERCE CENTER
APPENDIX F
WATER QUALITY DESIGN
Fj THOMAS & HUTTON

Water Quality Calculations
1-85 COMMERCE CENTER
Project No. 29101.0000
WET PONDS (Interconnectec
REVISED 01/21/2022
Project/Drainage Area: Acres Required Water Quality Volume: 1 104,377 Cubic Feet
Impervious Area: Acres (Project Area (Acres) X 43,560 SF X 1"/12 = Required Cubic Feet Volume)
"Percent Impervious Runoff Coeifficient: Rv=.05+0.9 (1) = 0.73
(Required Collection of First 1" of Rainfall from the Project Site and Release over a Minimum 48 Hour (Maximum 120 Hours) in Cubic Feet Per Second)
Min. 48-Hour Release Rate: 0.604 CFS Required Orifice Size: 5.00 Drawdown Time (Hours): 49.56
stage, depth, & vol:
Water Quality Elevation
Elev.
Area
Storage
(ft)
(sf)
(cu. ft)
764.00
57,638.42
0.00
770.00
117,862.09
533,343.09
Elevation
Pond Depth
Storage
(ft)
(ft)
(cu. ft)
764.00
0.00
0.00
765.49
1.49
104,377.02
766.00
2.00
140,088.00
Average Depth Calculation
Vpp Designed @ Elevation
1764.00
207,368.09
SA Designed @ Elevation
1764.00
42,675.63
Area of wet pond at the bottom of the shelf
37,691.34
Dmax over shelf
0.50
Perimeter of Permanent Pool
2,804.00
Width of submerged part of shelf
3.00
Volume over the shelf only
2,103.00
Average Depth
5.45
SA/DA Method
Drainage Area 39.22 acres
Table value 1.86
Surface Area Required 31,776.67 square feet
Orifice Flow Calculation
Q-CdA*sgrt(2gh)
Cd -
0.62 A
(Sharp Orifice)
A =
0.136
sf
g =
32.174
ft/s2
h =
1.49
ft
Q =
0.585
cfs
VPP-Vsheif
Die
AbottoMofshelf
Where:
D. =
Average depth in feet
V, =
Total volume of` -- pool (feet'}
V-" -
Volume o1iBr (hB Shelf Only (1eB1') -see below
A-..-, =
Area d wet pond at the bolMm of the shelf (1eef )
v-„
0.5`Deplh=„- -,
Perlmeter_„-Wldih,,,h=.,y,d w"s ,
Wh-
Dm„_„
- Depth of water at the deep side of the shelf as
measuired sl permenenl pool (feel)
Perimelerw,,,,,,,r,�wy
= Perimeter of Permanent pool at the bottom of the
shelf (feet}
Widi-
Width from the deep side to the dry side of the
she0 as mea d! at Permanent pool (ieet)
Table 1: Pmdmont and Moun tarn SAIDA Table (Adapfev from D-.1J, 7986)
10% o.51
0.43
0.37
0..
0.27 015
20% 0-B4
og0
a61
061
Om 0-0
90% 1.17
0.94
0.04
0.72
0.61 0.55
40% 1.51
1.24
1.09
0.91
0.78 0.71
50%. 1 za
1.1
1.1
1.13
e95 0 B7
50% 2.09
1.7
1.499
1.31
1.12 1.03
To% 2.51
2A9
1.a0
1.55
1.m 1.17
Ao% 2 92
2.41
2.07
1.82
1.62 t AD
100% 3-55 2.79 2.62 2.34 2.04 1-75

STORMWATER MANAGEMENT REPORT
1-85 COMMERCE CENTER
APPENDIX G
TIME VS. STAGE REPORTS
(DRAWDOWN TIME
iq THOMAS & HUTTON

0 5 10 15 20 25 30 35 40 45 50
Time (hrs)
Autodesk Storm and Sanitary Analysis

STORMWATER MANAGEMENT REPORT
1-85 COMMERCE CENTER
APPENDIX H
EROSION CONTROL
CALCULATIONS
A THOMAS & HUTTON

Iq
EROSION CONTROL CALCULATIONS
FOR:
1-85 COMMERCE CENTER
SALISBURY, NC
PREPARED FOR:
NORTHPOINT DEVELOPMENT
J - #2 9101.0000
AUGUST 25, 2021
Prepared by:
THOMAS Sc HUTTON

EROSION CONTROL CALCULATIONS
1-85 Commerce Center
Project: 1-85 Commerce Center
T&H Job Number: J-29101.0000
Location: 410 Webb Rd.
Salisbury, NC 28146
Date Prepared: August 25, 2021
Owner: Northpoint Development
Owner Address: 4805 Montgomery Rd., Suite 310
Cincinnati, OH 45212
Engineer: Thomas & Hutton
Engineer Address: 1020 Euclid Avenue
Charlotte, NC 28203
Phone: [phone]
H THOMAS & HUTTON
Page 1

TABLE OF CONTENTS
Section1.......................................................................................................................... Channel Analysis
Section2................................................................................................................................Slope Analysis
Section 3............................................................................................................Rip Rap Outlet Protection
Section4............................................................................................................................ Sediment Basins
H THOMAS & HUTTON
Page 2

EROSION CONTROL CALCULATIONS
1-85 COMMERCE CENTER
SECTION 1
CHANNEL ANALYSIS
29101.0000
Fq THOMAS Sc HUTTON

8/12/2021
ECMDS 7.0
NORTH
AMERICAN
GREEN
CHANNEL ANALYSIS
> > > Temporary Swale 1
Name
Temporary Swale 1
Discharge
18.61
Channel Slope
0.0234
Channel Bottom Width
2
Left Side Slope
3
Right Side Slope
3
Low Flow Liner
Retardence Class
C 6-12 in
Vegetation Type
Mix (Sod and Bunch)
Vegetation Density
Good 65-79%
Soil Type
Loam (MH)
Unreinforced Vegetation
North American Green
5401 St. Wendel -Cynthiana Rd.
Poseyville, Indiana 47633
Tel. [phone]
>Fax [phone]
www.nagreen.com
ECMDS v7.0
Normal
Permissible
Calculated
Safety
Staple
Phase
Reach
Discharge
9
Velocity
y
Mannin s N
I 9
I
Remarks
I
Depth
Shear Stress
Shear Stress
Factor
Pattern
Unreinforced
Straight 18.61 cfs 3.43 ft/s
1.05 ft
0.049 4 Ibs/ft2
1.54 Ibs/ft2
2.6 STABLE
Vegetation
Underlying
Straight 18.61 cfs 3.43 ft/s
1.05 ft
0.049 2.95 Ibs/ft2
0.92 Ibs/ft2
3.22 STABLE
Substrate
S75BN
Normal
Permissible
Calculated
Safety
Staple
Phase
Reach
Dischar a
9
Velocity
y
Mannin s N
I 9
I
Remarks
I
Depth
Shear Stress
Shear Stress
Factor
Pattern
S75BN
Straight 18.61 cfs 4.77 ft/s
0.85 ft
0.031 1.6 Ibs/ft2
1.25 Ibs/ft2
1.28
STABLE D
Unvegetated
Underlying
Straight 18.61 cfs 4.77 ft/s
0.85 ft
0.031 1.29 Ibs/ft2
0.77 Ibs/ft2
1.67
STABLE D
Substrate
DS75
Normal
Permissible
Calculated
Safety
Staple
Phase
Reach
Dischar a
9
Velocity
y
Mannin s N
I 9
I
Remarks
I
Depth
Shear Stress
Shear Stress
Factor
Pattern
DS75
Straight 18.61 cfs 4.77 ft/s
0.85 ft
0.031 1.6 Ibs/ft2
1.25 Ibs/ft2
1.28
STABLE D
Unvegetated
Underlying
Straight 18.61 cfs 4.77 ft/s
0.85 ft
0.031 1.29 Ibs/ft2
0.77 Ibs/ft2
1.67
STABLE D
Substrate
https://ecmds.com/project/l 48552/channel-analysis/205739/show 1 /1

8/12/2021
ECMDS 7.0
NORTH
AMERICAN
GREEN
ANALYSIS COMPUTATIONS
> > > > View Computation
Inputs
Channel Discharge (Q):
18.61 cfs
Peak Flow Period (H):
hours
Channel Slope (SO):
0.0234 ft/ft
Bottom Width (B):
2 ft
Left Side Slope (ZL):
3 (H : V)
Right Side Slope (ZR):
3 (H : V)
Existing Channel Bend:
No
Bend Coefficient (Kb):
1
Channel Bend Radius:
Retardance Class of Vegetation:
C 6-12 in
Vegetation Type:
Mix (Sod and Bunch)
Vegetation Density:
Good 65-79%
Soil Type:
Loam (MH)
Channel Lining Options
DS75 Protection Type
emporary
S75BN Protection Type
emporary
Basic Relationships
= Cross sectional area, ft2 (m2) _ (B * D) + (ZL/ 2 * D2) + (ZR/ 2 * D2)
Where:
B = Base width of channel, ft (m)
D = Flow depth, ft (m)
ZL= Left side bank slope (H : 1 V)
ZR= Right side bank slope (H : 1 V)
P = Wetted perimeter, ft (m) = B + ZL* D + ZR* D
R = Hydraulic radius, ft (m) = A / P
= Flow velocity, ft/s (m/s) = Q / A
Where:
Q = Channel discharge, cfs (cros)
aua Average bed shear stress, psf (Pa) = 62.4 * R * SO
Where:
SO = Gradient of channel, ft/ft (m/m)
auo = Maximum bed shear stress, psf (Pa) = 62.4 * D * So
Unvegetated Conditions Computations:
n = Manning's n = a * Tauab
and (iteratively solved).
n = 1.486 / Q * A * R(2/3)Soos
Where:
n = Manning's n
a = Product specific coefficient from performance testing
b = Product specific coefficient from performance testing
SFP= Product factor of safety = TauT/ Tauo
Where:
North American Green
5401 St. Wendel -Cynthiana Rd.
Poseyville, Indiana 47633
Tel. [phone]
>Fax [phone]
www.nagreen.com
ECMDS v7.0
https://ecmds.com/project/l 48552/channel-analysis/205739/calculations 1 /2

8/12/2021
ECMDS 7.0
TauT = Permissible shear stress from testing, psf (Pa)
auP= In place permissible shear, psf (Pa) = TauT/ alpha * (Taus+ alpha / 4.3)
Where:
alpha = unit conversion constant, 0.14 English, 6.5 Metric
Taus = Permissible shear stress of soil
SFL = Factor of safety of installed liner = Taup / Taua
Vegetated Computations:
n = Manning's n = alpha * Cn* Taua-0.4
and (iteratively solved).
n = 1.486 / Q * A * R(2/3)So05
Where:
alpha = Unit conversion constant, 0.213 English, 1.0 Metric
Cn = Vegetation retardance coefficient
SFP= Product factor of safety = TaUTv/ Tauo
Where:
TaUTv= Permissible shear stress from testing, psf (Pa)
auP= In place permissible shear, psf (Pa) = Taus/ (1 - CFTRM) * (n / ns)2
Where:
CFrRM = Coefficient of TRIM performance derived from testing Taus= Permissible shear stress of soil
ns= Manning's of soil bed if left unprotected
SFL= Factor of safety of installed liner = Taup/ Tau.
Unreinforced Vegetation
Predicted flow
Cross sectional
Wetted
Hydraulic
Flowvelocity
Froude
Calculated Shear
Phase
Mannings N
I
SFP/SFL
depth (D)
area (A)
perimeter (P)
radius (R)
(V)
number (FR)
Stress
Unreinforced
0.049 1.05 ft
5.42 ft2
8.65 ft
0.63 ft
3.43 ft/s
0.76
1.54 Ibs/ft2
2.6 (SFL)
Vegetation
Underlying
0.049 1.05 ft
5.42 ft2
8.65 ft
0.63 ft
3.43 ft/s
0.76
0.92 Ibs/ft2
3.22 (SFL)
Substrate
S75BN
Predicted flow
Cross sectional
Wetted
Hydraulic
Flowvelocity
Froude
Calculated Shear
Phase
Mannings N
I
SFP/SFL
depth (D)
area (A)
perimeter (P)
radius (R)
(V)
number (FR)
Stress
S75BN
0.031 0.85 ft
3.9 ft2
7.41 ft
0.53 ft
4.77 ft/s
1.16
1.25 Ibs/ft2
1.28 (SFP)
Unvegetated
Underlying
0.031 0.85 ft
3.9 ft2
7.41 ft
0.53 ft
4.77 ft/s
1.16
0.77 Ibs/ft2
1.67 (SFL)
Substrate
DS75
Predicted flow
Cross sectional
Wetted
Hydraulic
Flowvelocity
Froude
Calculated Shear
Phase
Mannings N
I
SFP/SFL
depth (D)
area (A)
perimeter (P)
radius (R)
(V)
number (FR)
Stress
DS75
0.031 0.85 ft
3.9 ft2
7.41 ft
0.53 ft
4.77 ft/s
1.16
1.25 Ibs/ft2
1.28 (SFP)
Unvegetated
Underlying
0.031 0.85 ft
3.9 ft2
7.41 ft
0.53 ft
4.77 ft/s
1.16
0.77 Ibs/ft2
1.67 (SFL)
Substrate
https://ecmds.com/project/l 48552/channel-analysis/205739/calculations 2/2

8/12/2021
ECMDS 7.0
NORTH
AMERICAN
GREEN
CHANNEL ANALYSIS
> > > Temporary Swale 2
Name
Temporary Swale 2
Discharge
68.63
Channel Slope
0.0162
Channel Bottom Width
2
Left Side Slope
3
Right Side Slope
3
Existing Bend Radius
100
Low Flow Liner
Retardence Class
C 6-12 in
Vegetation Type
Mix (Sod and Bunch)
Vegetation Density
Good 65-79%
Soil Type
Loam (MH)
Unreinforced Vegetation
North American Green
5401 St. Wendel -Cynthiana Rd.
Poseyville, Indiana 47633
Tel. [phone]
>Fax [phone]
www.nagreen.com
ECMDS v7.0
Normal
Permissible
Calculated
Safety
Staple
Phase
Reach
Dischar a
9
Velocity
y
Mannin s N
I 9
I
Remarks
I
Depth
Shear Stress
Shear Stress
Factor
Pattern
Unreinforced
Straight
68.63 cfs
4.4 ft/s
1.97 ft
0.045
4 Ibs/ft2
1.99 Ibs/ft2
2.01
STABLE
Vegetation
Underlying
Straight
68.63 cfs
4.4 ft/s
1.97 ft
0.045
2.56 Ibs/ft2
1.09 Ibs/ft2
2.35
STABLE
Substrate
Unreinforced
Bend
68.63 cfs
4.4 ft/s
1.97 ft
0.045
4 Ibs/ft2
2.54 Ibs/ft2
1.58
STABLE
Vegetation
Underlying
Bend
68.63 cfs
4.4 ft/s
1.97 ft
0.045
2.56 Ibs/ft2
1.39 Ibs/ft2
1.85
STABLE
Substrate
S75BN
Normal
Permissible
Calculated
Safety
Staple
Phase
Reach
Dischar a
9
Velocity
y
Mannin s N
I 9
I
Remarks
I
Depth
Shear Stress
Shear Stress
Factor
Pattern
S75BN
Straight
68.63 cfs
5.94 ft/s
1.66 ft
0.03
1.6 Ibs/ft2
1.68 Ibs/ft2
0.95
UNSTABLE
D
Unvegetated
Underlying
Straight
68.63 cfs
5.94 ft/s
1.66 ft
0.03
1.29 Ibs/ft2
0.94 Ibs/ft2
1.37
STABLE
D
Substrate
S75BN
Bend
68.63 cfs
5.94 ft/s
1.66 ft
0.03
1.6 Ibs/ft2
1.96 Ibs/ft2
0.82
UNSTABLE
D
Unvegetated
Underlying
Bend
68.63 cfs
5.94 ft/s
1.66 ft
0.03
1.29 Ibs/ft2
1.09 Ibs/ft2
1.18
STABLE
D
Substrate
DS75
Normal
Permissible
Calculated
Safety
Staple
Phase
Reach
Discharge
9
Velocity
y
Mannin s N
I 9
I
Remarks
I
Depth
Shear Stress
Shear Stress
Factor
Pattern
DS75
Straight
68.63 cfs
5.94 ft/s
1.66 ft
0.03
1.6 Ibs/ft2
1.68 Ibs/ft2
0.95
UNSTABLE
D
Unvegetated
Underlying
Straight
68.63 cfs
5.94 ft/s
1.66 ft
0.03
1.29 Ibs/ft2
0.94 Ibs/ft2
1.37
STABLE
D
Substrate
DS75
Bend
68.63 cfs
5.94 ft/s
1.66 ft
0.03
1.6 Ibs/ft2
1.96 Ibs/ft2
0.82
UNSTABLE
D
Unvegetated
Underlying
Bend
68.63 cfs
5.94 ft/s
1.66 ft
0.03
1.29 Ibs/ft2
1.09 Ibs/ft2
1.18
STABLE
D
Substrate
https://ecmds.com/project/l 48552/channel-analysis/208654/show 1 /2

8/12/2021
ECMDS 7.0
NORTH
AMERICAN
GREEN
ANALYSIS COMPUTATIONS
> > > > View Computation
Inputs
Channel Discharge (Q):
68.63 cfs
Peak Flow Period (H):
hours
Channel Slope (SO):
0.0162 ft/ft
Bottom Width (B):
2 ft
Left Side Slope (ZL):
3 (H : V)
Right Side Slope (ZR):
3 (H : V)
Existing Channel Bend:
Yes
Bend Coefficient (Kb):
Channel Bend Radius:
100 ft
Retardance Class of Vegetation:
C 6-12 in
Vegetation Type:
Mix (Sod and Bunch)
Vegetation Density:
Good 65-79%
Soil Type:
Loam (MH)
Channel Lining Options
DS75 Protection Type
emporary
S75BN Protection Type
emporary
Basic Relationships
= Cross sectional area, ft2 (m2) _ (B * D) + (ZL/ 2 * D2) + (ZR/ 2 * D2)
Where:
B = Base width of channel, ft (m)
D = Flow depth, ft (m)
ZL= Left side bank slope (H : 1 V)
ZR= Right side bank slope (H : 1 V)
P = Wetted perimeter, ft (m) = B + ZL* D + ZR* D
R = Hydraulic radius, ft (m) = A / P
= Flow velocity, ft/s (m/s) = Q / A
Where:
Q = Channel discharge, cfs (cros)
aua Average bed shear stress, psf (Pa) = 62.4 * R * SO
Where:
SO = Gradient of channel, ft/ft (m/m)
auo = Maximum bed shear stress, psf (Pa) = 62.4 * D * So
Unvegetated Conditions Computations:
n = Manning's n = a * Tauab
and (iteratively solved).
n = 1.486 / Q * A * R(2/3)Soos
Where:
n = Manning's n
a = Product specific coefficient from performance testing
b = Product specific coefficient from performance testing
SFP= Product factor of safety = TauT/ Tauo
Where:
North American Green
5401 St. Wendel -Cynthiana Rd.
Poseyville, Indiana 47633
Tel. [phone]
>Fax [phone]
www.nagreen.com
ECMDS v7.0
https://ecmds.com/project/l 48552/channel-analysis/208654/calculations 1 /3

8/12/2021
ECMDS 7.0
TauT = Permissible shear stress from testing, psf (Pa)
auP= In place permissible shear, psf (Pa) = TauT/ alpha * (Taus+ alpha / 4.3)
Where:
alpha = unit conversion constant, 0.14 English, 6.5 Metric
Taus = Permissible shear stress of soil
SFL = Factor of safety of installed liner = Taup / Taua
Vegetated Computations:
n = Manning's n = alpha * Cn* Taua-0.4
and (iteratively solved).
n = 1.486 / Q * A * R(2/3)So05
Where:
alpha = Unit conversion constant, 0.213 English, 1.0 Metric
Cn = Vegetation retardance coefficient
SFP= Product factor of safety = TaUTv/ Tauo
Where:
TaUTv= Permissible shear stress from testing, psf (Pa)
auP= In place permissible shear, psf (Pa) = Taus/ (1 - CFTRM) * (n / ns)2
Where:
CFTRM = Coefficient of TRIM performance derived from testing Taus= Permissible shear stress of soil
ns= Manning's of soil bed if left unprotected
SFL= Factor of safety of installed liner = Taup/ Tau.
Unreinforced Vegetation
Predicted flow
Cross sectional
Wetted
Hydraulic
Flowvelocity
Froude
Calculated Shear
Phase
Mannings N
I
SFP/SFL
depth (D)
area (A)
perimeter (P)
radius (R)
(V)
number (FR)
Stress
Unreinforced
0.045
1.97 ft
15.61 ft2
14.47 ft
1.08 ft
4.4 ft/s
0.75
1.99 Ibs/ft2
2.01 (SFL)
Vegetation
Underlying
0.045
1.97 ft
15.61 ft2
14.47 ft
1.08 ft
4.4 ft/s
0.75
1.09 Ibs/ft2
2.35 (SFL)
Substrate
Unreinforced
0.045
1.97 ft
15.61 ft2
14.47 ft
1.08 ft
4.4 ft/s
0.75
2.54 Ibs/ft2
1.58 (SFL)
Vegetation
Underlying
0.045
1.97 ft
15.61 ft2
14.47 ft
1.08 ft
4.4 ft/s
0.75
1.39 Ibs/ft2
1.85 (SFL)
Substrate
S75BN
Predicted flow
Cross sectional
Wetted
Hydraulic
Flowvelocity
Froude
Calculated Shear
Phase
Mannings N
I
SFP/SFL
depth (D)
area (A)
perimeter (P)
radius (R)
(V)
number (FR)
Stress
S75BN
0.03
1.66 ft
11.57 ft2
12.49 ft
0.93 ft
5.94 ft/s
1.09
1.68 Ibs/ft2
0.95 (SFP)
Unvegetated
Underlying
0.03
1.66 ft
11.57 ft2
12.49 ft
0.93 ft
5.94 ft/s
1.09
0.94 Ibs/ft2
1.37 (SFL)
Substrate
S75BN
0.03
1.66 ft
11.57 ft2
12.49 ft
0.93 ft
5.94 ft/s
1.09
1.96 Ibs/ft2
0.82 (SFP)
Unvegetated
Underlying
0.03
1.66 ft
11.57 ft2
12.49 ft
0.93 ft
5.94 ft/s
1.09
1.09 Ibs/ft2
1.18 (SFL)
Substrate
DS75
Predicted flow
Cross sectional
Wetted
Hydraulic
Flowvelocity
Froude
Calculated Shear
Phase
Mannings N
I
SFP/SFL
depth (D)
area (A)
perimeter (P)
radius (R)
(V)
number (FR)
Stress
DS75
0.03
1.66 ft
11.57 ft2
12.49 ft
0.93 ft
5.94 ft/s
1.09
1.68 Ibs/ft2
0.95 (SFP)
Unvegetated
Underlying
0.03
1.66 ft
11.57 ft2
12.49 ft
0.93 ft
5.94 ft/s
1.09
0.94 Ibs/ft2
1.37 (SFL)
Substrate
DS75
0.03
1.66 ft
11.57 ft2
12.49 ft
0.93 ft
5.94 ft/s
1.09
1.96 Ibs/ft2
0.82 (SFP)
Unvegetated
Underlying
0.03
1.66 ft
11.57 ft2
12.49 ft
0.93 ft
5.94 ft/s
1.09
1.09 Ibs/ft2
1.18 (SFL)
Substrate
https://ecmds.com/project/l 48552/channel-analysis/208654/calculations 2/3

8/12/2021
ECMDS 7.0
NORTH
AMERICAN
GREEN
CHANNEL ANALYSIS
> > > Temporary Swale 3
Name
Temporary Swale 3
Discharge
60.19
Channel Slope
0.0231
Channel Bottom Width
2
Left Side Slope
3
Right Side Slope
3
Low Flow Liner
Retardence Class
C 6-12 in
Vegetation Type
Mix (Sod and Bunch)
Vegetation Density
Good 65-79%
Soil Type
Loam (MH)
Unreinforced Vegetation
North American Green
5401 St. Wendel -Cynthiana Rd.
Poseyville, Indiana 47633
Tel. [phone]
>Fax [phone]
www.nagreen.com
ECMDS v7.0
Normal
Permissible
Calculated
Safety
Staple
Phase
Reach
Discharge
9
Velocity
y
Mannin s N
I 9
I
Remarks
I
Depth
Shear Stress
Shear Stress
Factor
Pattern
Unreinforced
Straight 60.19 cfs 5.16 ft/s
1.67 ft
0.042 4 Ibs/ft2
2.4 Ibs/ft2
1.67 STABLE
Vegetation
Underlying
Straight 60.19 cfs 5.16 ft/s
1.67 ft
0.042 2.17 Ibs/ft2
1.34 Ibs/ft2
1.62 STABLE
Substrate
S75BN
Normal
Permissible
Calculated
Safety
Staple
Phase
Reach
Dischar a
9
Velocity
y
Mannin s N
I 9
I
Remarks
I
Depth
Shear Stress
Shear Stress
Factor
Pattern
S75BN
Straight 60.19 cfs 6.69 ft/s
1.43 ft
0.029 1.6 Ibs/ft2
2.06 Ibs/ft2
0.78
UNSTABLE D
Unvegetated
Underlying
Straight 60.19 cfs 6.69 ft/s
1.43 ft
0.029 1.29 Ibs/ft2
1.17 Ibs/ft2
1.1
STABLE D
Substrate
DS75
Normal
Permissible
Calculated
Safety
Staple
Phase
Reach
Dischar a
9
Velocity
y
Mannin s N
I 9
I
Remarks
I
Depth
Shear Stress
Shear Stress
Factor
Pattern
DS75
Straight 60.19 cfs 6.69 ft/s
1.43 ft
0.029 1.6 Ibs/ft2
2.06 Ibs/ft2
0.78
UNSTABLE D
Unvegetated
Underlying
Straight 60.19 cfs 6.69 ft/s
1.43 ft
0.029 1.29 Ibs/ft2
1.17 Ibs/ft2
1.1
STABLE D
Substrate
https://ecmds.com/project/l 48552/channel-analysis/208655/show 1 /1

8/12/2021
ECMDS 7.0
NORTH
AMERICAN
GREEN
ANALYSIS COMPUTATIONS
> > > > View Computation
Inputs
Channel Discharge (Q):
60.19 cfs
Peak Flow Period (H):
hours
Channel Slope (SO):
0.0231 ft/ft
Bottom Width (B):
2 ft
Left Side Slope (ZL):
3 (H : V)
Right Side Slope (ZR):
3 (H : V)
Existing Channel Bend:
No
Bend Coefficient (Kb):
1
Channel Bend Radius:
100 ft
Retardance Class of Vegetation:
C 6-12 in
Vegetation Type:
Mix (Sod and Bunch)
Vegetation Density:
Good 65-79%
Soil Type:
Loam (MH)
Channel Lining Options
DS75 Protection Type
emporary
S75BN Protection Type
emporary
Basic Relationships
= Cross sectional area, ft2 (m2) _ (B * D) + (ZL/ 2 * D2) + (ZR/ 2 * D2)
Where:
B = Base width of channel, ft (m)
D = Flow depth, ft (m)
ZL= Left side bank slope (H : 1 V)
ZR= Right side bank slope (H : 1 V)
P = Wetted perimeter, ft (m) = B + ZL* D + ZR* D
R = Hydraulic radius, ft (m) = A / P
= Flow velocity, ft/s (m/s) = Q / A
Where:
Q = Channel discharge, cfs (cros)
aua Average bed shear stress, psf (Pa) = 62.4 * R * SO
Where:
SO = Gradient of channel, ft/ft (m/m)
auo = Maximum bed shear stress, psf (Pa) = 62.4 * D * So
Unvegetated Conditions Computations:
n = Manning's n = a * Tauab
and (iteratively solved).
n = 1.486 / Q * A * R(2/3)Soos
Where:
n = Manning's n
a = Product specific coefficient from performance testing
b = Product specific coefficient from performance testing
SFP= Product factor of safety = TauT/ Tauo
Where:
North American Green
5401 St. Wendel -Cynthiana Rd.
Poseyville, Indiana 47633
Tel. [phone]
>Fax [phone]
www.nagreen.com
ECMDS v7.0
https://ecmds.com/project/l 48552/channel-analysis/208655/calculations 1 /2

8/12/2021
ECMDS 7.0
TauT = Permissible shear stress from testing, psf (Pa)
auP= In place permissible shear, psf (Pa) = TauT/ alpha * (Taus+ alpha / 4.3)
Where:
alpha = unit conversion constant, 0.14 English, 6.5 Metric
Taus = Permissible shear stress of soil
SFL = Factor of safety of installed liner = Taup / Taua
Vegetated Computations:
n = Manning's n = alpha * Cn* Taua-0.4
and (iteratively solved).
n = 1.486 / Q * A * R(2/3)So05
Where:
alpha = Unit conversion constant, 0.213 English, 1.0 Metric
Cn = Vegetation retardance coefficient
SFP= Product factor of safety = TaUTv/ Tauo
Where:
TaUTv= Permissible shear stress from testing, psf (Pa)
auP= In place permissible shear, psf (Pa) = Taus/ (1 - CFTRM) * (n / ns)2
Where:
CFrRM = Coefficient of TRIM performance derived from testing Taus= Permissible shear stress of soil
ns= Manning's of soil bed if left unprotected
SFL= Factor of safety of installed liner = Taup/ Tau.
Unreinforced Vegetation
Predicted flow
Cross sectional
Wetted
Hydraulic
Flowvelocity
Froude
Calculated Shear
Phase
Mannings N
I
SFP/SFL
depth (D)
area (A)
perimeter (P)
radius (R)
(V)
number (FR)
Stress
Unreinforced
0.042 1.67 ft
11.65 ft2
12.53 ft
0.93 ft
5.16 ft/s
0.94
2.4 Ibs/ft2
1.67 (SFL)
Vegetation
Underlying
0.042 1.67 ft
11.65 ft2
12.53 ft
0.93 ft
5.16 ft/s
0.94
1.34 Ibs/ft2
1.62 (SFL)
Substrate
S75BN
Predicted flow
Cross sectional
Wetted
Hydraulic
Flowvelocity
Froude
Calculated Shear
Phase
Mannings N
I
SFP/SFL
depth (D)
area (A)
perimeter (P)
radius (R)
(V)
number (FR)
Stress
S75BN
0.029 1.43 ft
8.96 ft2
11.02 ft
0.81 ft
6.69 ft/s
1.31
2.06 Ibs/ft2
0.78 (SFP)
Unvegetated
Underlying
0.029 1.43 ft
8.96 ft2
11.02 ft
0.81 ft
6.69 ft/s
1.31
1.17 Ibs/ft2
1.1 (SFL)
Substrate
DS75
Predicted flow
Cross sectional
Wetted
Hydraulic
Flowvelocity
Froude
Calculated Shear
Phase
Mannings N
I
SFP/SFL
depth (D)
area (A)
perimeter (P)
radius (R)
(V)
number (FR)
Stress
DS75
0.029 1.43 ft
8.96 ft2
11.02 ft
0.81 ft
6.69 ft/s
1.31
2.06 Ibs/ft2
0.78 (SFP)
Unvegetated
Underlying
0.029 1.43 ft
8.96 ft2
11.02 ft
0.81 ft
6.69 ft/s
1.31
1.17 Ibs/ft2
1.1 (SFL)
Substrate
https://ecmds.com/project/l 48552/channel-analysis/208655/calculations 2/2

EROSION CONTROL CALCULATIONS
1-85 COMMERCE CENTER
SECTION 2
SLOPE ANALYSIS
29101.0000
Fq THOMAS Sc HUTTON

NORTH
AMERICAN
GREEN
SLOPE ANALYSIS
> > > 2:1 Slopes
North American Green
5401 St. Wendel -Cynthiana Rd.
Poseyville, Indiana 47633
Tel. [phone]
> Fax [phone]
www.nagreen.com
ECMDS v7.0
Country United States
State/Region North Carolina
City Charlotte
Annual R Factor 175.00
Adjusted R Factor 8.75
Total Slope Length 100
Protection Type Permanent
Protection Period 1
Beginning Month March
Slope Gradient (1-1:1) 2
Soil Type Loam
K Factor 0.25
Reach 1
Start: Oft End: 100 ft
Vegetation Type: 65-79%
Material ASL bare ASL mat
MSL bare
MSL mat
Soil Loss
SF
Remarks
Staple / App
Tolerance
Rate
S75BN 0.1 in 0.0 in
0.2 in
0.0 in
0.25 in
>10
STABLE
C
DS75 0.1 in 0.0 in
0.2 in
0.0 in
0.25 in
>10
STABLE
C
Estb. Veg. 2.0 in 0.0 in
N/A in
N/A in
0.03 in
0.734
UNSTABLE
--
https://ecmds.com/project/l 48552/slope-analysis/205780/show 1 /1

11-WINI ail
NORTH
AMERICAN
GREEN
ANALYSIS COMPUTATIONS
> > > > View Computation
Project Parameters
Project Location:
Charlotte, North Carolina United States
Slope Length:
100
Project Start:
March
Protection Period:
1
Slope Gradient (_H:1V):
2
Soil Type:
Loam
Project Analysis - S75BN
Slope Steepness Factor (S factor)
S factor if slope gradient > 9%:
7.01
S factor if slope length < 15 ft:
2.14
S factor Utilized:
7.01
Length Factor (L factor)
Slope Angle (0) =
26.57
Horizontal Slope Distance = A =
96.49
Rill:Interril = p = (sin 6 / 0.0896) / [3.0(sin 6) 0.8 + 0.56] * 2 =
4.67
Slope Length Exponent = m = (3 / ( 1 + (3) =
0.82
L factor =
1.19
RUSLE Variables
Soil Erodibility Factor:
0.25
Slope length & Gradient Factor (LS Factor):
8.33
Periodic Rainfall Factor (R Factor):
8.75
Annual Rainfall Factor:
175
Cover Factor (C Factor):
0.03
Soil Loss Tolerance (SLT):
0.25
Average Soil Loss
ASLBare = 0.00595 * RLSK =
0.108
ASLMat = ASLBare * C factor =
0.003
Maximum Soil Loss (MSL)
MSLBare = ASLBare * 1.73 =
0.19
MSLMat = MSLBare * C factor =
0.006
Safety Factor (SF)
SF = SLT / MSLMat = 43.958
Project Analysis - DS75
Slope Steepness Factor (S factor)
S factor if slope gradient > 9%:
7.01
S factor if slope length < 15 ft:
2.14
S factor Utilized:
7.01
Length Factor (L factor)
Slope Angle (0) =
26.57
Horizontal Slope Distance = A =
96.49
Rill:Interril = p = (sin 6 / 0.0896) / [3.0(sin 6) 0.8 + 0.56] * 2 =
4.67
Slope Length Exponent = m = (3 / ( 1 + (3) =
0.82
L factor =
1.19
RUSLE Variables
North American Green
5401 St. Wendel -Cynthiana Rd.
Poseyville, Indiana 47633
Tel. [phone]
> Fax [phone]
www.nagreen.com
ECMDS v7.0
https://ecmds.com/project/l 48552/slope-analysis/205780/calculations 1 /2

11-WINI ail
Soil Erodibility Factor:
0.25
Slope length & Gradient Factor (LS Factor):
8.33
Periodic Rainfall Factor (R Factor):
8.75
Annual Rainfall Factor:
175
Cover Factor (C Factor):
0.03
Soil Loss Tolerance (SLT):
0.25
Average Soil Loss
ASLBare = 0.00595 * RLSK =
0.108
ASLMat = ASLBare * C factor =
0.003
Maximum Soil Loss (MSL)
MSLBare = ASLBare * 1.73 =
0.19
MSLMat = MSLBare * C factor =
0.006
Safety Factor (SF)
SF = SLT / MSLMat = 43.958
Project Analysis - Estb. Veg.
Slope Steepness Factor (S factor)
S factor if slope gradient > 9%:
7.01
S factor if slope length < 15 ft:
2.14
S factor Utilized:
7.01
Length Factor (L factor)
Slope Angle (0) =
26.57
Horizontal Slope Distance = A =
96.49
Rill:Interril = (3 = (sin 6 / 0.0896) / [3.0(sin 6) 0.8 + 0.56] * 0.5
4.67
Slope Length Exponent = m = (3 / ( 1 + (3) =
0.82
L factor =
1.12
RUSLE Variables
Soil Erodibility Factor:
0.25
Slope length & Gradient Factor (LS Factor):
7.85
Periodic Rainfall Factor (R Factor):
8.75
Annual Rainfall Factor:
175
Cover Factor (C Factor):
0.02
Soil Loss Tolerance (SLT):
0.03
Average Soil Loss
ASLBare = 0.00595 * RLSK =
2.044
ASLMat = ASLBare * C factor =
0.041
Safety Factor (SF)
SF = SLT / MSLMat = 0.734
https://ecmds.com/project/l 48552/slope-analysis/205780/calculations 2/2

NORTH
AMERICAN
GREEN
SLOPE ANALYSIS
> > > 2.5:1 Slopes
North American Green
5401 St. Wendel -Cynthiana Rd.
Poseyville, Indiana 47633
Tel. [phone]
> Fax [phone]
www.nagreen.com
ECMDS v7.0
Country United States
State/Region North Carolina
City Charlotte
Annual R Factor 175.00
Adjusted R Factor 8.75
Total Slope Length 100
Protection Type Permanent
Protection Period 1
Beginning Month March
Slope Gradient (1-1:1) 2.5
Soil Type Loam
K Factor 0.25
Reach 1
Start: Oft End: 100 ft
Vegetation Type: 65-79%
Material ASL bare ASL mat
MSL bare
MSL mat
Soil Loss
SF
Remarks
Staple / App
Tolerance
Rate
S75BN 0.1 in 0.0 in
0.2 in
0.0 in
0.25 in
>10
STABLE
C
DS75 0.1 in 0.0 in
0.2 in
0.0 in
0.25 in
>10
STABLE
C
Estb. Veg. 1.7 in 0.0 in
N/A in
N/A in
0.03 in
0.883
UNSTABLE
--
https://ecmds.com/project/l 48552/slope-analysis/205782/show 1 /1

11-WINI ail
NORTH
AMERICAN
GREEN
ANALYSIS COMPUTATIONS
> > > > View Computation
Project Parameters
Project Location:
Charlotte, North Carolina United States
Slope Length:
100
Project Start:
March
Protection Period:
1
Slope Gradient (_H:1V):
2.5
Soil Type:
Loam
Project Analysis - S75BN
Slope Steepness Factor (S factor)
S factor if slope gradient > 9%:
5.74
S factor if slope length < 15 ft:
1.92
S factor Utilized:
5.74
Length Factor (L factor)
Slope Angle (0) =
21.8
Horizontal Slope Distance = A =
97.63
Rill:Interril = p = (sin 6 / 0.0896) / [3.0(sin 6) 0.8 + 0.56] * 2 =
4.32
Slope Length Exponent = m = (3 / ( 1 + (3) =
0.81
L factor =
1.22
RUSLE Variables
Soil Erodibility Factor:
0.25
Slope length & Gradient Factor (LS Factor):
7.01
Periodic Rainfall Factor (R Factor):
8.75
Annual Rainfall Factor:
175
Cover Factor (C Factor):
0.03
Soil Loss Tolerance (SLT):
0.25
Average Soil Loss
ASLBare = 0.00595 * RLSK =
0.091
ASLMat = ASLBare * C factor =
0.003
Maximum Soil Loss (MSL)
MSLBare = ASLBare * 1.73 =
0.159
MSLMat = MSLBare * C factor =
0.005
Safety Factor (SF)
SF = SLT / MSLMat = 52.541
Project Analysis - DS75
Slope Steepness Factor (S factor)
S factor if slope gradient > 9%:
5.74
S factor if slope length < 15 ft:
1.92
S factor Utilized:
5.74
Length Factor (L factor)
Slope Angle (0) =
21.8
Horizontal Slope Distance = A =
97.63
Rill:Interril = p = (sin 6 / 0.0896) / [3.0(sin 6) 0.8 + 0.56] * 2 =
4.32
Slope Length Exponent = m = (3 / ( 1 + (3) =
0.81
L factor =
1.22
RUSLE Variables
North American Green
5401 St. Wendel -Cynthiana Rd.
Poseyville, Indiana 47633
Tel. [phone]
> Fax [phone]
www.nagreen.com
ECMDS v7.0
https://ecmds.com/project/l 48552/slope-analysis/205782/calculations 1 /2

11-WINI ail
Soil Erodibility Factor:
0.25
Slope length & Gradient Factor (LS Factor):
7.01
Periodic Rainfall Factor (R Factor):
8.75
Annual Rainfall Factor:
175
Cover Factor (C Factor):
0.03
Soil Loss Tolerance (SLT):
0.25
Average Soil Loss
ASLBare = 0.00595 * RLSK =
0.091
ASLMat = ASLBare * C factor =
0.003
Maximum Soil Loss (MSL)
MSLBare = ASLBare * 1.73 =
0.159
MSLMat = MSLBare * C factor =
0.005
Safety Factor (SF)
SF = SLT / MSLMat = 52.541
Project Analysis - Estb. Veg.
Slope Steepness Factor (S factor)
S factor if slope gradient > 9%:
5.74
S factor if slope length < 15 ft:
1.92
S factor Utilized:
5.74
Length Factor (L factor)
Slope Angle (0) =
21.8
Horizontal Slope Distance = A =
97.63
Rill:Interril = (3 = (sin 6 / 0.0896) / [3.0(sin 6) 0.8 + 0.56] * 0.5
4.32
Slope Length Exponent = m = (3 / ( 1 + (3) =
0.81
L factor =
1.14
RUSLE Variables
Soil Erodibility Factor:
0.25
Slope length & Gradient Factor (LS Factor):
6.52
Periodic Rainfall Factor (R Factor):
8.75
Annual Rainfall Factor:
175
Cover Factor (C Factor):
0.02
Soil Loss Tolerance (SLT):
0.03
Average Soil Loss
ASLBare = 0.00595 * RLSK =
1.698
ASLMat = ASLBare * C factor =
0.034
Safety Factor (SF)
SF = SLT / MSLMat = 0.883
https://ecmds.com/project/l 48552/slope-analysis/205782/calculations 2/2

11-fMOZOAil
NORTH
AMERICAN
GREEN
SLOPE ANALYSIS
> > > 3:1 Slopes
North American Green
5401 St. Wendel -Cynthiana Rd.
Poseyville, Indiana 47633
Tel. [phone]
> Fax [phone]
www.nagreen.com
ECMDS v7.0
Country United States
State/Region North Carolina
City Charlotte
Annual R Factor 175.00
Adjusted R Factor 8.75
Total Slope Length 100
Protection Type Permanent
Protection Period 1
Beginning Month March
Slope Gradient (1-1:1) 3
Soil Type Loam
K Factor 0.25
Reach 1
Start: Oft End: 100 ft
Vegetation Type: 65-79%
Material ASL bare ASL mat
MSL bare
MSL mat
Soil Loss
SF
Remarks
Staple / App
Tolerance
Rate
S75BN 0.1 in 0.0 in
0.1 in
0.0 in
0.25 in
>10
STABLE
C
DS75 0.1 in 0.0 in
0.1 in
0.0 in
0.25 in
>10
STABLE
C
Estb. Veg. 1.4 in 0.0 in
N/A in
N/A in
0.03 in
1.047
STABLE
--
https://ecmds.com/project/l 48552/slope-analysis/205783/show 1 /1

11-WINI ail
NORTH
AMERICAN
GREEN
ANALYSIS COMPUTATIONS
> > > > View Computation
Project Parameters
Project Location:
Charlotte, North Carolina United States
Slope Length:
100
Project Start:
March
Protection Period:
1
Slope Gradient (_H:1V):
3
Soil Type:
Loam
Project Analysis - S75BN
Slope Steepness Factor (S factor)
S factor if slope gradient > 9%:
4.81
S factor if slope length < 15 ft:
1.75
S factor Utilized:
4.81
Length Factor (L factor)
Slope Angle (0) =
18.43
Horizontal Slope Distance = A =
98.31
Rill:Interril = p = (sin 6 / 0.0896) / [3.0(sin 6) 0.8 + 0.56] * 2 =
4.02
Slope Length Exponent = m = (3 / ( 1 + (3) =
0.8
L factor =
1.24
RUSLE Variables
Soil Erodibility Factor:
0.25
Slope length & Gradient Factor (LS Factor):
5.96
Periodic Rainfall Factor (R Factor):
8.75
Annual Rainfall Factor:
175
Cover Factor (C Factor):
0.03
Soil Loss Tolerance (SLT):
0.25
Average Soil Loss
ASLBare = 0.00595 * RLSK =
0.078
ASLMat = ASLBare * C factor =
0.002
Maximum Soil Loss (MSL)
MSLBare = ASLBare * 1.73 =
0.134
MSLMat = MSLBare * C factor =
0.004
Safety Factor (SF)
SF = SLT / MSLMat = 62.104
Project Analysis - DS75
Slope Steepness Factor (S factor)
S factor if slope gradient > 9%:
4.81
S factor if slope length < 15 ft:
1.75
S factor Utilized:
4.81
Length Factor (L factor)
Slope Angle (0) =
18.43
Horizontal Slope Distance = A =
98.31
Rill:Interril = p = (sin 6 / 0.0896) / [3.0(sin 6) 0.8 + 0.56] * 2 =
4.02
Slope Length Exponent = m = (3 / ( 1 + (3) =
0.8
L factor =
1.24
RUSLE Variables
North American Green
5401 St. Wendel -Cynthiana Rd.
Poseyville, Indiana 47633
Tel. [phone]
> Fax [phone]
www.nagreen.com
ECMDS v7.0
https://ecmds.com/project/l 48552/slope-analysis/205783/calculations 1 /2

11-WINI ail
Soil Erodibility Factor:
0.25
Slope length & Gradient Factor (LS Factor):
5.96
Periodic Rainfall Factor (R Factor):
8.75
Annual Rainfall Factor:
175
Cover Factor (C Factor):
0.03
Soil Loss Tolerance (SLT):
0.25
Average Soil Loss
ASLBare = 0.00595 * RLSK =
0.078
ASLMat = ASLBare * C factor =
0.002
Maximum Soil Loss (MSL)
MSLBare = ASLBare * 1.73 =
0.134
MSLMat = MSLBare * C factor =
0.004
Safety Factor (SF)
SF = SLT / MSLMat = 62.104
Project Analysis - Estb. Veg.
Slope Steepness Factor (S factor)
S factor if slope gradient > 9%:
4.81
S factor if slope length < 15 ft:
1.75
S factor Utilized:
4.81
Length Factor (L factor)
Slope Angle (0) =
18.43
Horizontal Slope Distance = A =
98.31
Rill:Interril = (3 = (sin 6 / 0.0896) / [3.0(sin 6) 0.8 + 0.56] * 0.5
4.02
Slope Length Exponent = m = (3 / ( 1 + (3) =
0.8
L factor =
1.14
RUSLE Variables
Soil Erodibility Factor:
0.25
Slope length & Gradient Factor (LS Factor):
5.5
Periodic Rainfall Factor (R Factor):
8.75
Annual Rainfall Factor:
175
Cover Factor (C Factor):
0.02
Soil Loss Tolerance (SLT):
0.03
Average Soil Loss
ASLBare = 0.00595 * RLSK =
1.433
ASLMat = ASLBare * C factor =
0.029
Safety Factor (SF)
SF = SLT / MSLMat = 1.047
https://ecmds.com/project/l 48552/slope-analysis/205783/calculations 2/2

EROSION CONTROL CALCULATIONS
1-85 COMMERCE CENTER
SECTION 3
RIP RAP OUTLET PROTECTION
IZIZIZI�
Fq THOMAS Sc HUTTON

Rip Rap Apron Design
Project Name: 29101.0000 - Northpoint
Drainage Specialist: KSC Date: August 25, 2021
Checked By: NH Date: August 25, 2021
Step 1. Determine the tailwater depth from the channel characteristics below the pipe outlet for the
design capacity of the pipe. If the tailwater depth is less than half the outlet pipe diameter, it
is classifies as minimum tailwater conditions. If the tailwater is greater than half the pipe
diameter, it is classified as maximum tailwater conditions. Pipes that outlet onto wide flat
areas with no defined channel are assumed to have a minimum tailwater condition unless
reliable flood stage elevations show otherwise.
Rational Method for Flow
Total Drainage Area (Acres):
40.7
Outlet pipe diameter, Do (in.)
36
Tailwater depth (Feet)
1.7
Tailwater Method To Be Used
Max TW (Fig. 8.06b)
Discharge (cfs)
46.5
Velocity (ft./s)
6.6
Step 2. Based on the tailwater conditions determined in Step 1, enter Figure 8.06a or Figure 8.06b
and determine the d50 rip rap size and minimum apron length (La). The d50 size is the median
stone size in a well -graded rip rap apron.
Step 3. Determine the apron width at the pipe outlet, the apron shape, and the apron width at the
outlet end from the same figure used in Step 2.
Minimum TW Maximum TW
Riprap d50, (ft.) 0.2
Minimum apron length, La (ft.) ** 22 14
Apron width at pipe outlet ft. 9 9
Apron shape `AT = 1 T W = Do + ALa
Apron width at outlet end (ft.) 9
** - Minimum Apron Length Is 10 Feet per CLDS 20.23
Step 4. Determine the maximum Stone Diameter. D.. = 1.5 X d50
Determine the Apron Thickness, Ta = 1.5 X dm.
Minimum TW Maximum TW
Max Stone Diameter, dmax (Inches): - 4
Apron Thickness (Inches): 10
** - Minimum Apron Thickness Is 10 Inches per CLDS 20.23
Step 5. Fit the rip rap apron to the site by making it level for the minimum length La. Extend the
apron farther downstream and along the channel banks until stability is assured. Keep apron
as straight as possible and align it with the flow of the receiving stream. Make any necessary
alignment bends near the pipe outlet so that the entrance into the receiving stream is straight.
Some locations may require lining of the entire channel cross section to assure stability. It
may be necessary to increase the size of the rip rap where protection of the channel side
slopes is necessary. Where overfalls exist at pipe outlets or flows are excessive, a plunge pool
should be considered.

Figure 8.06b: Design of outlet protectic
tailwater condition (Tw>=0.6 diameter)
3 i7°
I
Outlet = Ba + 0.4L8
pipe
diameter (Ibj
lOD
go
30
70
�-
60 .. _ . .. ...........,.
50
20
10
0
Discharge (Olsec)
Curves may not be extrapolated-
FipurO 0.06b Design of outlet protection tram a r—d pipe Sowing full. maximum tailwatercondidon (T a D.5 diameler)-
8.06.4
1Cr
a
a
Rec. L'+9a
1 Adjust Blue line to appropriate discharge
Adjust Green line to line up with either diameter
2 curve or with the bottom of the diameter line if
discharge line and diameter line don't cross.
Read d50 Rip Rap size.
Adjust Red line to line up with either diameter
0 curve or with the bottom of the diameter line if
discharge line and diameter line don't cross.
Read Minimum Apron Length.
Adjust Blue line to appropriate discharge
Adjus[ Green Line to appropriate velocity

EROSION CONTROL CALCULATIONS
1-85 COMMERCE CENTER
SECTION 4
SEDIMENT BASINS
IZIZIZI]
Fq THOMAS Sc HUTTON

Temporary Sediment Basin 03
This structure is intended for less than 3 years of use. Structures intended
for more than 3 years of use should be desinged as permanent structures.
User Input Data
Calculated Value
Reference Data
Designed By: NH Date: 6/22/2021
checked By: WBS Date: 2/3/202C
company: Thomas & Hutton
Project Name: Northpoint
Project No.: 29101.0000
Site Location (City/Town)
Salisbury, NC
Sediment Basin Id.
3
Total Drainage Area (acres)
45
Step 1. Determine peak flow, Q, for the basin drainage area (Appendix 8.03).
Q10 (cfs)
168
Step 2. Determine my site limitations for the sediment pool eleea4asl emergency
spillway or top of the, dam.
Minimum pool elevation (ft)
756
Maximum pool elevation (ft)
770
Step 3. Determine basin volumes:
• Compute nunutrw. —I—, required (1800 flt/sae disturbed).
• Specify sediment clemout level to be marked on riser (one-half the design
wlumc referenced to the top of the user) and sed—t storage area to be
cleared after the dam is built.
Disturbed acreage (ac) 40
Min Volume (ft') 72000
Sediment cleanout elevation (ft) 764
Sediment storage volume (ft') 211332
Step 4. Determine area and shape of basis:
• Check lengiWmcith ratio (should be 2:1 to 6:1).
• Compme the basin surface area at principal spillway elevation.
• Check the ratio of basin surface area to peak inflow rate (should be greater
than or equal to 435 fl'lcfs). Employ diversions with additional traps and
basins to redact area drained,
Determine barrel capacity required for site conditions (im-inum capacity for Qp
is the 2-year peak —ff,, Qc.
Length/width ratio 3
Is length/width ratio between 2-6? YES, PROCEED
Basin surface area @ principal spillway (ft) 78588
Ratio: basin surface area/Qto 467.7857143
Is ratio — 435 ft2/cfs? YES
Step 5. Determine the principal spillway discharge capacity.
• The combined capacities of the principal and emergency spillways most he
at least the 10-year peak flow for the mtize watershed of the basin_
• The principal spillway is analyzed for three possible limiting flow types:
Weir flow. Orifice flow, and (ripe flow_ The principal spillway discharge
capacity is the smallest of these three flow rates. Discharges through a
skimmer should be disregarded during this computation. Weir, orifice and
pipe flow may be determined by the following egaauons,
1. Weir Flow: Q = CLH"
Where.
Q = discharge in cubic feet per second (cfs)
C = weir coefficient, use 3.1 for corrugated metal pipe risers.
L = circumference of the rise to feet
H = head above riser crest in feet

Weir coefficient, C
Riser circumference, L (ft)
Head above riser crest, H (ft)
Q,N (cfs)
2. Orifice Flow: Q = CA (2gHp'
wbae.
0 = discharge in cubic feet per second (cfs)
C =orifice coefficient, use C = 0.6 for corrugated metal pipe nisrns_
A = cross -sectional area of the riser pipe is square feet
g=accelerarwa due to gravity, 32-2 ftluc2
H = head abolr riser crest m feet
Orifice coefficient, Co
Riser cross -sectional area, A (ft2)
Accleration due to gravity, g (fUs2)
Head above riser crest, H (ft)
Discharge, Qo (cfs)
2gh os
3. Pipe Flow: 0 = a b-1- T kl L
where_
Q = discharge m cubic feet per second (cfs)
a = cross -sectional area of the banal in square fat
g = acceleration due to gavty. 32.2 R/see
h = head abore the centedme of the mdet end of the barrel
Km = coefficient of minor losses. can be assumed to be 1.0 for
most principal spillway systems
L = barrel length in feet
Kp = pipe fnchon coefficient:
5087W (See Table a 7 for Kp salves for
= &13 common size of pipe )
n = Manning's coefficient of roughness, use h = 0.025 for
corrugated metal pipe
n = 0.015 for reinforced concrete pipe
di = inside diameter of the barrel is inches
Select riser and barrel dimensions so that the riser has a cross -sectional area
at least 15 times that of the barrel. Spillway hydraulics ace improved by
maximizing wrir Bow and mmimian6 orifice f3 -- See Table g 07b for
recommended mer/barrel proportion,
Barrel diameter (ft)
Barrel cross -sectional area, a (ft2)
Accleration due to gravity, g (fUs2)
Head above outlet end of barrel, h (ft)
Minor loss coefficieint, Km
Barrel length, L (ft)
Mannings coeffienct of roughness, n
Inside diameter of barrel, d, (in)
Pipe friction coefficient, Kp
Discharge, Qo (cfs)
RISER
Selecr trail 6— and beret dwmuaas. V. the ueu. orifice sod pp, ft—,
equations to deunameifd.2.yearpekdischargen passed without acrir-.n g
the emageocv spulway. Determine riser sire from Figure 8,07b, Check +he
head crud sage rcquirerueurs. If the design wage rs too hsph, choox ]weer
dmremsom and rccakulau. As a minimum. ut the eles-anon ofthe riser anhe
same eleranon as the sop of the sediment pool. A nm bright 2 to 5 times the
barrel diametn rs ucommead<d- Select ib<r�e oftrasb guard.
Selecr a dewarmag detiice, U a skimmer ss used, refer ra the mauufacnaen
dew.-.q date. m Table 6,64 b_
3.1 CcmP=3.1 (2 ft)
24
1.45
129.9047223
0.637 CcmP=0.6
36
32.2
1.45
221.5995468
3
7.1
32.2
4.6
1.0 Km=1.0 (typical)
55
0.013 ncmP=0.025 npcp=0.015
36
0.00723 0.0266 Table 8.07a
78.56872834 65.3774526
Table 8.07b

tsrep o. MUP aaaiseep cane_
Fnswe tbst aateseep class are ao closer than s_ ft from a pipe 7oi t CWler
must project al least 1.5 ft fsom the pipe. Indwate wa,ertigbt coaoeclioas.
Step 7. Destge-tiflotmtiaa Meek
Determine the weight of water displaced by the empty riser, and desigp a
block with baoyam weight 1.1 tunes the weight of water displaced,
Weight of water displaced by the empty riser
Buoyant weight
Step S. Design outlet.
Detesmine dixhazge wlm ty from the barrel. Design oode, proleek— to
a —at stable coadinons Riprap placemeat is uwadly a—sam (Appendix
5.06).
Discharge velocity, V (ft/s)
See Appendix 8.06 for riprap sizing, if necessary
Step 9. f7esign emergmcu aPdh,.y_
• Determine du -Fired capacity for dse emeegency sptdway as
0. = om — Op (op z at)
• Fram Table=er Table®ulect the width and depth of she outlet.
depeadrag on sod con&-.,hs general, the —dn bmmm idd. said
lawn slopes me pcef ed to minimize exit—losilm st ,tip —rill -I
Bow.
• Ana acceptable altesaatnv is the tau ofthe tts,n egwtioa
Q = CLH's
LVhere this ophou is used. the maxtmom Salto of C should be ?_S_ L
is the bottom width of the spillway at the crest. said 11 is the depth of
flow abo, a the spell—y nest m feet Note hfaoaiug s ebasmel vp nou
sb—ld not be used to sin she sptlhcaycrest. Howera.it,ta—ldbeused
m dcstga the outlet chamel below the spillway crest.
• The tool of be emergency and principle spillway copse@ies mwt equal
et exceed the tecl-ed 10-yam peak disebazge.
• sel the elei anon of the —t of the emeegeeey sp,Hway a mimmum of I
foot A— the —, of the nun
OPTION 1
Qto
Qp
Emergency spillway capacity, Q. (cfs)
1765
1941.5
11.11520132 9.24901755
Table 8.07c
Table 8.07d
OPTION 2
168 Weir coefficient, C
65.37745261 Bottom width of spillway crest, L (ft)
102.6225474 Depth of flow above spillway crest, H (ft)
Emergency spillway capacity, Q. (cfs)
Qp + Ole 168
Does (Qp+ Qe) equal or exceed Q10? YES, PROCEED
Step to- spWw•ay approach ,reboot
Adjust be spillway alignment so this, the content action mad oulet section
me stea:alit. The enmance width should be 1.5 times the width ofthe control
section with&—litss,nstoon to the width ofdse conrol seetsoo. Approach
channel should slope lou'eN the resm•ou sm less thou 2s e.
Width of control section (ft) 100
Width of entrance (ft) 20
Slope of approach channel (%) 10
Is width of the entrance section 1.5xcontrol section
width? YES, PROCEED
Is approach channel >/= 2%? YES, PROCEED
Step 11, Spillway control uctiw
• Lease the e-1 section m the spillway year where it iate,xcls the
e:suasiau of the c-t.h- of the dam.
• Keep a lml area so extend at least 20 ft ugtseam ftom the emlet said cf
the comrol iassli . to ensure it sts & altg®ent.
• side slap,, should be 3' L
step 12. Design spillway exit section.
• Spillway exit shoud alip with the control sates and bass, the same
bottom -dth said side slopes,
• Slope should be saaffie t to etatatata super ,1-1 flow, ben make sme st
does mt csrute erosi s, ss,lociaes f site coodiaoais. (Stay- withm slope
ranges in appropriate design tables )
• Exsmd the exs, channel re a pomr wbere the westt may h releaud withow
damage.
2.8
50
1.45
244.444
309.822
YES, PROCEED

Step 13. Size the embankment.
• So the design el—ac of the top oflhc dam a minimum of 1 P abo.. the
wner soma.. fm the design flan m 1he e..li y spillway.
• Comttucmd height should be 10ai pseaser dnn the deep to allow fm
sehlcaunt-
• Base top a d1h oc the desvgp hnghl-
• Set stde s14es25.1 or fm,-
• Delesmine depth of cutoff beach Pom stte bonngs. 1! shadd extend to a
stable, nght sad layer (a mimmmn of � P deep),
• Select bo-w s,,,,be emergency sPdwav cut will P.,de ■ aigaificant
am —of fill.
Step 14. Em—control
• L—le and desigp dn,erstons to protect —t,.k eat end spillway
(Pucd,. Smndmds and Sperff itdant, 6.20, Ampmnn Di—M.).
• Select swfim ptott hen measmatocontrolaeoatw(Pvcnce Smndards
and Spaafftc,tm— 610, Tiatpomry S•.d-ag,- 61 a, N fching; and 61 d,
R"P)_
• Select poundcosxr fen emergency spillway to pm,,de protection fox
d.,pt flow relouty and sire aondsnons Riprap stone — geouank
Mix may be requvred in erodsble soils ar wb- the spillway is nit m
ssodishtrbed soils.
Step 15. Safety
• Crmst a fence and install --g asgns as ceded,

8/26/2021
ECMDS 7.0
NORTH
AMERICAN
GREEN
SPILLWAY ANALYSIS
> > > Temporary Sediment Basin 02
Name
Temporary Sediment Basin
02
Discharge
168
Peak Flow Period
34.16
Channel Slope
0.01
Channel Bottom Width
50
Low Flow Liner
Retardence Class C 6-12 in
Vegetation Type Mix (Sod and Bunch)
Vegetation Density Good 65-79%
Soil Type Loam (MH)
North American Green
5401 St. Wendel -Cynthiana Rd.
Poseyville, Indiana 47633
Tel. [phone]
>Fax [phone]
www.nagreen.com
ECMDS v7.0
Unreinforced Vegetation
- Class C -
Mix (Sod & Bunch) - Good 65-79%
Normal
Permissible
Calculated
Safety
Staple
Phase
Reach
Discharge
Velocity
Mannings N
Remarks
Depth
Shear Stress
Shear Stress
Factor
Pattern
Unreinforced Straight
168 cfs
2.91 ft/s 1.15 ft 0.054 4 Ibs/ft2
0.72 Ibs/ft2
5.56 STABLE
Vegetation
Underlying Straight
168 cfs
2.91 ft/s 1.15 ft 0.054 4.44 Ibs/ft2
0.69 Ibs/ft2
6.46 STABLE
Substrate
S75BN
Normal
Permissible
Calculated
Safety
Staple
Phase
Reach
Dischar a
g
Velocity
y
Mannin s N
I g
I
Remarks
I
Depth
Shear Stress
Shear Stress
Factor
Pattern
S75BN
Straight 168 cfs 3.96 ft/s
0.85 ft
0.033 1.6 Ibs/ft2
0.53 Ibs/ft2
3.03
STABLE D
Unvegetated
Underlying
Straight 168 cfs 3.96 ft/s
0.85 ft
0.033 1.29 Ibs/ft2
0.51 Ibs/ft2
2.52
STABLE D
Substrate
DS75
Normal
Permissible
Calculated
Safety
Staple
Phase
Reach
Dischar a
g
Velocity
y
Mannin s N
I g
I
Remarks
I
Depth
Shear Stress
Shear Stress
Factor
Pattern
DS75
Straight 168 cfs 3.96 ft/s
0.85 ft
0.033 1.6 Ibs/ft2
0.53 Ibs/ft2
3.03
STABLE D
Unvegetated
Underlying
Straight 168 cfs 3.96 ft/s
0.85 ft
0.033 1.29 Ibs/ft2
0.51 Ibs/ft2
2.52
STABLE D
Substrate
https://ecmds.com/project/l 48552/spillway-analysis/205788/show 1 /1

8/26/2021
ECMDS 7.0
NORTH
AMERICAN
GREEN
ANALYSIS COMPUTATIONS
> > > > View Computation
Project Parameters
Discharge:
168
Peak Flow Period:
34.16
Left Side Slope (ZL):
0
Right Side Slope (ZR):
0
Bottom Width:
50
Spillway Slope:
0.01
Bend Coefficient (Kb):
1
Retardance Class (A - E):
C 6-12 in
Vegetation Type:
Mix (Sod and Bunch)
Vegetation Density:
Good 65-79%
Soil Type:
Loam (MH)
Channel Lining Options
Protection Type JPermanent
Basic Relationships
= Cross sectional area, ft2 (m2) _ (B * D) + (ZL/ 2 * D2) + (ZR/ 2 * D2)
Where:
B = Base width of channel, ft (m)
D = Flow depth, ft (m)
ZL= Left side bank slope (H : 1 V)
ZR= Right side bank slope (H : 1 V)
P = Wetted perimeter, ft (m) = B + ZL* D + ZR* D
R = Hydraulic radius, ft (m) = A / P
V = Flow velocity, ft/s (m/s) = Q / A
Where:
Q = Channel discharge, cfs (cros)
aua Average bed shear stress, psf (Pa) = 62.4 * R * SO
Where:
SO = Gradient of channel, ft/ft (m/m)
auo = Maximum bed shear stress, psf (Pa) = 62.4 * D * So
Unvegetated Conditions Computations:
n = Manning's n = a * Tauab
and (iteratively solved).
n = 1.486 / Q * A * R(2/3)Soos
Where:
n = Manning's n
a = Product specific coefficient from performance testing
b = Product specific coefficient from performance testing
SFP= Product factor of safety = TauT/ Tauo
Where:
TauT = Permissible shear stress from testing, psf (Pa)
aup= In place permissible shear, psf (Pa) = TauT/ alpha * (Taus+ alpha / 4.3)
North American Green
5401 St. Wendel -Cynthiana Rd.
Poseyville, Indiana 47633
Tel. [phone]
>Fax [phone]
www.nagreen.com
ECMDS v7.0
https://ecmds.com/project/l 48552/spillway-analysis/205788/calculations 1 /2

8/26/2021
ECMDS 7.0
Where:
alpha = unit conversion constant, 0.14 English, 6.5 Metric
Taus = Permissible shear stress of soil
SFL = Factor of safety of installed liner = Taup / Taua
Vegetated Computations:
n = Manning's n = alpha * Cn* Taua-0.4
and (iteratively solved).
n = 1.486 / Q * A * R(2/3)So05
Where:
alpha = Unit conversion constant, 0.213 English, 1.0 Metric
Cn = Vegetation retardance coefficient
SFP= Product factor of safety = TauTV/ Tauo
Where:
TauTV= Permissible shear stress from testing, psf (Pa)
aup= In place permissible shear, psf (Pa) = Taus/ (1 - CFTRM) * (n / ns)2
Where:
CFTRM = Coefficient of TRIM performance derived from testing Taus= Permissible shear stress of soil
ns= Manning's of soil bed if left unprotected
SFL= Factor of safety of installed liner = Taup/ Tau.
Unreinforced Vegetation
- Class C -
Mix (Sod & Bunch) - Good 65-79%
Predicted flow
Cross sectional
Wetted
Hydraulic
Flow velocity
Froude
Calculated Shear
Phase
Mannings N
SFP/SFL
depth (D)
area (A)
perimeter (P)
radius (R)
(V)
number (FR)
Stress
Unreinforced 0.054
1.15 ft
57.63 ft2
52.31 ft
1.1 ft
2.91 ft/s
0.49
0.72 Ibs/ft2
5.56 (SFL)
Vegetation
Underlying 0.054
1.15 ft
57.63 ft2
52.31 ft
1.1 ft
2.91 ft/s
0.49
0.69 Ibs/ft2
6.46 (SFL)
Substrate
S75BN
Predicted flow
Cross sectional
Wetted
Hydraulic
Flowvelocity
Froude
Calculated Shear
Phase
Mannings N
I
I
SFP/SFL
depth (D)
area (A)
perimeter (P)
radius (R)
(V)
number (FR)
Stress
S75BN
0.033 0.85 ft
42.28 ft2
51.69 ft
0.82 ft
3.96 ft/s
0.77
0.53 Ibs/ft2
3.03 (SFP)
Unvegetated
Underlying
0.033 0.85 ft
42.28 ft2
51.69 ft
0.82 ft
3.96 ft/s
0.77
0.51 Ibs/ft2
2.52 (SFL)
Substrate
DS75
Predicted flow
Cross sectional
Wetted
Hydraulic
Flowvelocity
Froude
Calculated Shear
Phase
Mannings N
I
I
SFP/SFL
depth (D)
area (A)
perimeter (P)
radius (R)
(V)
number (FR)
Stress
DS75
0.033 0.85 ft
42.28 ft2
51.69 ft
0.82 ft
3.96 ft/s
0.77
0.53 Ibs/ft2
3.03 (SFP)
Unvegetated
Underlying
0.033 0.85 ft
42.28 ft2
51.69 ft
0.82 ft
3.96 ft/s
0.77
0.51 Ibs/ft2
2.52 (SFL)
Substrate
https://ecmds.com/project/l 48552/spillway-analysis/205788/calculations 2/2

8/26/2021
ECMDS 7.0
NORTH
AMERICAN
GREEN
SPILLWAY ANALYSIS
> > > Temporary Sediment Basin 02
Name
Temporary Sediment Basin
02
Discharge
168
Peak Flow Period
34.16
Channel Slope
0.01
Channel Bottom Width
50
Low Flow Liner
Retardence Class C 6-12 in
Vegetation Type Mix (Sod and Bunch)
Vegetation Density Good 65-79%
Soil Type Loam (MH)
North American Green
5401 St. Wendel -Cynthiana Rd.
Poseyville, Indiana 47633
Tel. [phone]
>Fax [phone]
www.nagreen.com
ECMDS v7.0
Unreinforced Vegetation
- Class C -
Mix (Sod & Bunch) - Good 65-79%
Normal
Permissible
Calculated
Safety
Staple
Phase
Reach
Discharge
Velocity
Mannings N
Remarks
Depth
Shear Stress
Shear Stress
Factor
Pattern
Unreinforced Straight
168 cfs
2.91 ft/s 1.15 ft 0.054 4 Ibs/ft2
0.72 Ibs/ft2
5.56 STABLE
Vegetation
Underlying Straight
168 cfs
2.91 ft/s 1.15 ft 0.054 4.44 Ibs/ft2
0.69 Ibs/ft2
6.46 STABLE
Substrate
S75BN
Normal
Permissible
Calculated
Safety
Staple
Phase
Reach
Dischar a
g
Velocity
y
Mannin s N
I g
I
Remarks
I
Depth
Shear Stress
Shear Stress
Factor
Pattern
S75BN
Straight 168 cfs 3.96 ft/s
0.85 ft
0.033 1.6 Ibs/ft2
0.53 Ibs/ft2
3.03
STABLE D
Unvegetated
Underlying
Straight 168 cfs 3.96 ft/s
0.85 ft
0.033 1.29 Ibs/ft2
0.51 Ibs/ft2
2.52
STABLE D
Substrate
DS75
Normal
Permissible
Calculated
Safety
Staple
Phase
Reach
Dischar a
g
Velocity
y
Mannin s N
I g
I
Remarks
I
Depth
Shear Stress
Shear Stress
Factor
Pattern
DS75
Straight 168 cfs 3.96 ft/s
0.85 ft
0.033 1.6 Ibs/ft2
0.53 Ibs/ft2
3.03
STABLE D
Unvegetated
Underlying
Straight 168 cfs 3.96 ft/s
0.85 ft
0.033 1.29 Ibs/ft2
0.51 Ibs/ft2
2.52
STABLE D
Substrate
https://ecmds.com/project/l 48552/spillway-analysis/205788/show 1 /1

8/26/2021
ECMDS 7.0
NORTH
AMERICAN
GREEN
ANALYSIS COMPUTATIONS
> > > > View Computation
Project Parameters
Discharge:
168
Peak Flow Period:
34.16
Left Side Slope (ZL):
0
Right Side Slope (ZR):
0
Bottom Width:
50
Spillway Slope:
0.01
Bend Coefficient (Kb):
1
Retardance Class (A - E):
C 6-12 in
Vegetation Type:
Mix (Sod and Bunch)
Vegetation Density:
Good 65-79%
Soil Type:
Loam (MH)
Channel Lining Options
Protection Type JPermanent
Basic Relationships
= Cross sectional area, ft2 (m2) _ (B * D) + (ZL/ 2 * D2) + (ZR/ 2 * D2)
Where:
B = Base width of channel, ft (m)
D = Flow depth, ft (m)
ZL= Left side bank slope (H : 1 V)
ZR= Right side bank slope (H : 1 V)
P = Wetted perimeter, ft (m) = B + ZL* D + ZR* D
R = Hydraulic radius, ft (m) = A / P
V = Flow velocity, ft/s (m/s) = Q / A
Where:
Q = Channel discharge, cfs (cros)
aua Average bed shear stress, psf (Pa) = 62.4 * R * SO
Where:
SO = Gradient of channel, ft/ft (m/m)
auo = Maximum bed shear stress, psf (Pa) = 62.4 * D * So
Unvegetated Conditions Computations:
n = Manning's n = a * Tauab
and (iteratively solved).
n = 1.486 / Q * A * R(2/3)Soos
Where:
n = Manning's n
a = Product specific coefficient from performance testing
b = Product specific coefficient from performance testing
SFP= Product factor of safety = TauT/ Tauo
Where:
TauT = Permissible shear stress from testing, psf (Pa)
aup= In place permissible shear, psf (Pa) = TauT/ alpha * (Taus+ alpha / 4.3)
North American Green
5401 St. Wendel -Cynthiana Rd.
Poseyville, Indiana 47633
Tel. [phone]
>Fax [phone]
www.nagreen.com
ECMDS v7.0
https://ecmds.com/project/l 48552/spillway-analysis/205788/calculations 1 /2

8/26/2021
ECMDS 7.0
Where:
alpha = unit conversion constant, 0.14 English, 6.5 Metric
Taus = Permissible shear stress of soil
SFL = Factor of safety of installed liner = Taup / Taua
Vegetated Computations:
n = Manning's n = alpha * Cn* Taua-0.4
and (iteratively solved).
n = 1.486 / Q * A * R(2/3)So05
Where:
alpha = Unit conversion constant, 0.213 English, 1.0 Metric
Cn = Vegetation retardance coefficient
SFP= Product factor of safety = TauTV/ Tauo
Where:
TauTV= Permissible shear stress from testing, psf (Pa)
aup= In place permissible shear, psf (Pa) = Taus/ (1 - CFTRM) * (n / ns)2
Where:
CFTRM = Coefficient of TRIM performance derived from testing Taus= Permissible shear stress of soil
ns= Manning's of soil bed if left unprotected
SFL= Factor of safety of installed liner = Taup/ Tau.
Unreinforced Vegetation
- Class C -
Mix (Sod & Bunch) - Good 65-79%
Predicted flow
Cross sectional
Wetted
Hydraulic
Flow velocity
Froude
Calculated Shear
Phase
Mannings N
SFP/SFL
depth (D)
area (A)
perimeter (P)
radius (R)
(V)
number (FR)
Stress
Unreinforced 0.054
1.15 ft
57.63 ft2
52.31 ft
1.1 ft
2.91 ft/s
0.49
0.72 Ibs/ft2
5.56 (SFL)
Vegetation
Underlying 0.054
1.15 ft
57.63 ft2
52.31 ft
1.1 ft
2.91 ft/s
0.49
0.69 Ibs/ft2
6.46 (SFL)
Substrate
S75BN
Predicted flow
Cross sectional
Wetted
Hydraulic
Flowvelocity
Froude
Calculated Shear
Phase
Mannings N
I
I
SFP/SFL
depth (D)
area (A)
perimeter (P)
radius (R)
(V)
number (FR)
Stress
S75BN
0.033 0.85 ft
42.28 ft2
51.69 ft
0.82 ft
3.96 ft/s
0.77
0.53 Ibs/ft2
3.03 (SFP)
Unvegetated
Underlying
0.033 0.85 ft
42.28 ft2
51.69 ft
0.82 ft
3.96 ft/s
0.77
0.51 Ibs/ft2
2.52 (SFL)
Substrate
DS75
Predicted flow
Cross sectional
Wetted
Hydraulic
Flowvelocity
Froude
Calculated Shear
Phase
Mannings N
I
I
SFP/SFL
depth (D)
area (A)
perimeter (P)
radius (R)
(V)
number (FR)
Stress
DS75
0.033 0.85 ft
42.28 ft2
51.69 ft
0.82 ft
3.96 ft/s
0.77
0.53 Ibs/ft2
3.03 (SFP)
Unvegetated
Underlying
0.033 0.85 ft
42.28 ft2
51.69 ft
0.82 ft
3.96 ft/s
0.77
0.51 Ibs/ft2
2.52 (SFL)
Substrate
https://ecmds.com/project/l 48552/spillway-analysis/205788/calculations 2/2

Pi THOMAS Sc HUTTON

STORMWATER MANAGEMENT REPORT
1-85 COMMERCE CENTER
APPENDIX
POST -DEVELOPMENT STORMWATER PIPING AND
INLET DESIGN CONSIDERATIONS
USING ANALYZE GRAVITY NETWORK
H THOMAS Sc HUTTON

HEC-22
Energy Grade Line Computations
Struct.
Q
EGLo
HGLo
Total Pipe
EGU
HGU
Ea
EGLa
Surface Elev.
ID
(cfs)
(ft)
(ft)
Loss
(ft)
(ft)
(ft)
(ft)
(ft)
(ft)
Pi THOMAS - HUTTON
T:�AutoC4D�Reports�HEC-22�HEC-22 Reporting

HEC-22
Storm Drain Computations
Structure ID
Length
(ft)
Drainage
Area
(ac)
Runoff
Coeff "C"
Tc
(min)
Rain "I"
(in/hr)
Runoff
1.Q"
(cfs)
Known Q
(cfs)
Total Q
(cfs)
Pipe Dia.
(in)
Velocity
Design
(ft/s)
Invert Elevation
Slope
From To
U/S I D/S
2 1 68 0.62 0.50 ill 6.10 47.9 47.91 54 6.6 761.98 761.77 0.30%
3_ 12 107 1.43 0.50 10 6.15� 44.5 44.5 42 7.8 763.51 762.98 0.50%
4 3 150 1.44 0.50 10 6.21 40.5 40.5 42 7.6 764.26 763.51 0.50%
PiTHOMAS- HUTTON
T:�AutoC4D�Reports�HEC-22�HEC-22 Reporting

HEC-22
Inlet Capacity Results
Structure
Q=CIA/Kc
(cfs)
Known
Q
(cfs)
Longitudinal
Slope
SL
(ft/ft)
Cross
Slope
Sx
(ft/ft)
Cross
Slope
SW
(ft/ft)
Prev.
Bypass
Flow
(cfs)
Total
Gutter
Flow
(cfs)
Depth
d
(ft)
Gutter
Width
(ft)
Spread
T
(ft)
Inlet Type
Grate
Length
(in)
Grate
Width
(in)
Curb
Opening
Length
(in)
Curb
Opening
Height
(in)
Intercept
Flow
Qi
(cfs)
Bypass
Flow
Qb
(cfs)
Bypass
Structure
Remark
6
5.2
-1.00
0.02
0.02
0.08
0.081
5.2
5.31
0.4
0.4
1.0
15.8
Combination
40.0
10.9
40.0
4.2
4.2
5.2
5.3
5
5.3
-1.00
1.0
16.1
Combination
40.0
10.9
40.0
4
5.3
-1.00
0.02
0.08
5.3
0.4
1.0
16.1
Combination
40.0
10.9
40.0
4.2
5.3
3
5.2
-1.00
0.02
0.08
5.2
0.4
1.0
15.9
Combination
40.0
10.9
40.0
4.2
5.2
22
2.2
0.02
0.02
0.08
2.2
0.2
1.0
7.5
Combination
20.0
10.9
20.0
4.2
0.9
1.3
2
2.3
0.02
0.02
0.08
2.3
0.2
1.01
7.6
Combination
20.01
10.9
20.01
4.2
0.91
1.4
11
1.0
0.02
0.02
0.08
1.0
0.2
1.0
5.3
Combination
20.0
10.9
20.0
4.2
0.5
0.4
12
0.5
-1.00
0.02
0.081
0.5
0.1
1.0
0.9
Combination
20.0
10.9
20.0
4.2
0.5
14
1.2
0.02
0.02
0.08
1.2
0.2
1.0
5.7
Combination
20.0
10.9
20.0
4.2
0.6
0.6
16
0.4
0.02
0.02
0.08
0.4
0.1
1.0
3.4
Combination
20.0
10.9
20.0
4.2
0.3
0.1
15
0.9
0.021
0.02
0.08
0.91
0.2
1.0
5.1
Combination
20.0
10.9
20.0
4.2
0.5
0.4
13
1 1.2
0.02
0.02
0.08
1.2
0.2
1.0
5.8
Combination
20.0
10.9
20.0
4.2
0.6
0.6
20
1.4
-1.00
0.02
0.02
1.4
-0.1
50.0
9.9
Grate inlet
23.8
23.8
1.4
21
1.0
-1.00
0.02
0.021
1.0
-0.1
50.0
8.0
Grate inlet
23.8
23.8
1.0
17
1.7
-1.00
0.02
0.02
1.7
-0.1
50.0
11.0
Grate inlet
23.8
23.8
1.7
10
5.2
-1.00
0.01
0.02
5.2
0.1
50.0
18.5
Grate inlet
47.5
23.8
5.2
18
0.9
-1.001
0.02
0.02
0.9
-0.1
50.01
7.6
Grate inlet
23.8
23.8
0.9
19
1 1.7
-1.00
0.02
0.02
1.7
-0.1
50.0
11.1
Grate inlet
23.8
23.8
1 1.7
9
4.9
-1.00
0.01
0.02
4.9
0.1
50.0
17.8
Grate inlet
47.5
23.81
4.9
8
4.8
-1.00
0.01
0.021
4.8
0.1
50.0
17.6
Grate inlet
47.5
23.8
4.8
7
4.8
-1.00
0.01
0.02
4.8
0.1
50.0
17.6
Grate inlet
47.5
23.8
4.8
29
4.5
-1.001
0.02
0.02
0.9
5.4
-0.1
50.0
13.4
Grate inlet
47.5
23.8
1
5.4
28
1 6.4
-1.00
0.02
0.02
6.4
-0.1
50.0
14.9
Grate inlet
47.5
23.8
6.4
26
6.5
-1.00
0.02
0.02
6.5
-0.1
50.0
15.0
Grate inlet
47.5
23.8
6.5
25
6.5
-1.00
0.02
0.021
6.5
-0.1
50.0
15.0
Grate inlet
47.5
23.8
6.5
24
6.2
-1.00
0.02
0.02
6.2
-0.1
50.0
14.6
Grate inlet
47.5
23.8
6.2
34
1.1
0.02
0.02
0.08
1.1
0.2
1.0
5.8
Combination
35.5
23.6
35.5
4.2
0.7
0.4
33
33
3.1
-1.001
0.02
0.08
0.8
3.81
0.2
1.0
8.5
Combination
71.0
23.6
71.0
4.2
3.8
32
1 0.9
0.03
0.02
0.08
0.9
0.2
1.0
4.8
Combination
35.5
23.6
35.5
4.2
0.6
0.3
33
31
0.4
0.03
0.02
0.08
0.4
0.11
1.0
3.0
Combination
35.5
23.6
35.5
4.2
0.3
0.1
38
3.7
0.03
0.02
0.081
3.7
0.2
1.0
8.8
Combination
35.5
23.6
35.5
4.2
1.5
2.2
37
4.4
-1.00
0.02
0.08
4.4
0.3
1.0
13.3
Combination
40.0
10.9
40.0
4.2
4.4
39
0.5
-1.00
0.02
0.08
0.5
-0.0
1.0
0.7
Combination
35.5
23.6
35.5
4.2
0.5
40
9.1
-1.001
0.02
0.08
9.11
0.4
1.0
14.4
Combination
71.0
23.6
71.0
4.2
9.1
35
1 0.5
-1.00
0.02
0.08
0.5
0.1
1.0
0.5
Combination
71.0
23.6
71.0
4.2
0.5
36
5.4
-1.00
0.02
0.08
5.4
0.41
1.01
16.4
Combination
40.0
10.9
40.0
4.2
5.4
27
6.5
-1.00
0.021
0.021
6.5
-0.11
50.01
15.0
Grate inlet
47.5
23.8
6.5
30
2.41
0.00
0.021
0.081
2.4
0.31
1.01
10.7
Grate inlet
47.5
23.8
1.5
0.9129
4THOMAS-HUTTON
T: WutoCAD�Reports�HEC-22�HEC-22 Reporting

STORMWATER MANAGEMENT REPORT
1-85 COMMERCE CENTER
APPENDIX J
NCDOT
STORMWATER SYSTEM ANALYSIS
H THOMAS Sc HUTTON

I(h/
f J` (IJ( c��/J ` �I
\<r 1 \ )
S �
1 lr J/I�o 1� � 779')
lJ
780
\ 1 1
I / I BASIN I 1�\I \
( ( 1 j AREA: 1.1 ACRE o I C C \ \ / \ i G
I �1 >ei775
l (
( 762 ! 1 � f � \ f
OH
7—
N,\ _
l % 9 ?
OHP PROP. DITCH I—
�� P CENTERLINE — — s� 49i
786
INV.: 784.01GI #QWIB
I —
\ Leo
o >sy >s— L P QC INT I FR: 787.51 _7 5 — I
/ \ ` �g > — UHP — } INV. IN: 782.60 (NW) —
\ 02 >9j _ > >88 — �a> � • 199 LF x ` HP INV. OUT: 782.60 (S})
` 1
0� 77s 777
/ I' _ d C _ —... • \ _77s'779 780'.781->e/,
I � � �� ,- J � v��rS b .� O WEB
144 LF 18x �
rjr f _ `�g R ► ' — _ _ — •r—.� RCP.® � FES
I I � .� _ , � �� '� I,/ pAp SRISp' � �_ � � '_ ``-; --� �— r '' �. — ,;? • — • -� 5p� INV ?781� 8 — —
`•
V
S V� _-_ W VAR
O
y _
I Lfl ��1 fly �b Ar Sv c — — — J
1-85 COMMERCE CENTER
DRAINAGE AREA EXHIBIT
CLIENT:
NORTHPOINT DEVELOPMENT
LOCATION: 410 WEBB RD, SALISBURY, NC 28146
DATE: 7/12/21 DRAWN BY: SHEET: E1.1
JOB NUMBER: J- 29101.0000 REVIEWED BY: SCALE: 1" = 50'
I'll-
C,16g1
J <�
a
rp\

n
L � /
1 I J ( ) J r/f /o
_
71
/o
0
774
NWL: 764.0
POND 4 _ _ ` BOP: 756.0
— — TOP: 770.0
NWL: 764.0 77' �� 1 �, �✓
— — 7 BOP: 759.0 < S
— 5 �
770 J
BASIN 2 �' 767 766 EX. DITCH 2 ACCESS POINT J
— AREA: 2.5 ACRE - �111� t / CENTERLINE C
_ n Q INV.: 762.00
®0.65�
_ = — �.� _ �_p — -146 LFRCP - _ j
�� —INV.. 762.95 / — 1 _ I
`�' 765 IIIII764 76.3 62
116,
\/ , WEBS `` � 0
R/ W ROAD SRI -
v —
VARIES -
L _
o \ — — — — '�. FR. 7 I
61
1-85 COMMERCE CENTER ��> ` ��;_��— — �� ����
THOMAS
DRAINAGE AREA EXHIBIT I"I HUT TO N a�f �T� / 7' — ~`
CLIENT: � LI
NORTHPOINT DEVELOPMENT 1020 Euclid Avenue - t �I �` ti
LOCATION: 410 WEBB RD, SALISBURY, NC 28146 Charlotte, NC 28202 • 980.201 .5505
DATE: 7/12/21 DRAWN BY: SHEET: E1.2 ^I / �� ^ J �� \
W•thomasandhutton.com
JOB NUMBER: J- 29101.0000 REVIEWED BY: SCALE: 1" = 50'

Channel Report
Hydraflow Express Extension for Autodesk® Civil 3D® by Autodesk, Inc.
Proposed Ditch 1
Triangular
Side Slopes (z:1)
= 3.00, 2.00
Total Depth (ft)
= 2.00
Invert Elev (ft)
= 786.39
Slope (%)
= 2.95
N-Value
= 0.015
Calculations
Compute by:
Known Q
Known Q (cfs)
= 6.20
Elev (ft)
789.00
788.50
788.00
787.50
787.00
786.50
785.50
1 2 3 4 5
Monday, Jul 12 2021
Highlighted
Depth (ft) =
0.59
Q (cfs) =
6.200
Area (sqft) =
0.87
Velocity (ft/s) =
7.12
Wetted Perim (ft) =
3.19
Crit Depth, Yc (ft) =
0.83
Top Width (ft) =
2.95
EGL (ft) =
1.38
Rain Fall Intensity
100 yr - 5 min storm event
i=8.7in/hr
From NOAA 14
Rational Method
Q = CiA
= 0.65 x 8.7 in/hr x 1.1 acres
= 6.2 cfs
Depth (ft)
Section
6
Reach (ft)
7 8 9 10 11 12
G.O 1
2.11
1.61
0.61
0.11
-0.39
■ 2w:z l

Channel Report
Hydraflow Express Extension for Autodesk® Civil 3D® by Autodesk, Inc.
Existing Ditch 2
Triangular
Side Slopes (z:1)
= 3.00, 2.00
Total Depth (ft)
= 2.00
Invert Elev (ft)
= 786.39
Slope (%)
= 2.95
N-Value
= 0.015
Calculations
Compute by:
Known Q
Known Q (cfs)
= 20.40
Elev (ft)
789.00
788.50
788.00
787.50
787.00
786.50
785.50
1 2 3 4 5
Monday, Jul 12 2021
Highlighted
Depth (ft) =
0.93
Q (cfs) =
20.40
Area (sqft) =
2.16
Velocity (ft/s) =
9.43
Wetted Perim (ft) =
5.02
Crit Depth, Yc (ft) =
1.33
Top Width (ft) =
4.65
EGL (ft) =
2.31
Rain Fall Intensity
100 yr - 5 min storm event
i=8.7in/hr
From NOAA 14
Rational Method
Q = CiA
= 0.65 x 8.7 in/hr x 3.6 acres
= 20.4 cfs
Depth (ft)
Section
6
Reach (ft)
7 8 9 10 11 12
G.O 1
2.11
1.61
0.61
0.11
-0.39
■ 2w:z l

HEC-22
Energy Grade Line Computations
Struct.
Q
EGLo
HGLo
Total Pipe
EGU
HGU
Ea
EGLa
Surface Elev.
ID
(cfs)
(ft)
(ft)
Loss
(ft)
(ft)
(ft)
(ft)
(ft)
(ft)
DW1C 1 783.20 783.20 1 1 783.59
DW16 1 7.81 783.551 783.201 0.721 784.271 783.92 1.81 784.441 787.51
DW1A 1 6.21 784.521 784.321 0.701 785.221 785.021 1.71 785.671 786.21
DW26 1 1 763.601 763.601 1 1 1 1 1 763.98
DW2A 1 20.41 764.261 763.601 1.221 765.471 764.821 3.31 765.611 764.73
Pi THOMAS s HUTTON
Z: �29101 �29101.000O�Engineering�Calculations and Reports�Storm Water�HEC-ZZ�HEC-ZZ Reporting Pipes in ROW

HEC-22
Storm Drain Computations
Structure ID
Length
(ft)
Drainage
Area
(ac)
Runoff
Coeff "C"
Tc
(min)
Rain "I"
(in/hr)
Runoff
"Q"
(cfs)
Known Q
(cfs)
Total Q
(cfs)
Pipe Dia.
(in)
Velocity
Design
(ft/s)
Invert Elevation
Slope
From To
U/S I D/S
DW113 DW1C 144 0.32 0.50 5 9.84 1.6
DW1A DW113 199F— 6.2
i
DW2A DW213 1501 1 1 20.4
7.8 18 4.8 782.60 781.88 0.50%
6.2 18 5.4 784.01 782.60 0.71%
20.4 24 6.5 762.35 761.60 0.50%
PiTHOMAS- HUTTON
Z: �29101 �29101.000OJEngineering�Calculations and Reports �$tOrm Water�HEC-22�HEC-22 Reporting Pipes in ROW