SW3210301_Design Calculations (Stormwater - Phase 3)_20210511

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STORMWATER MANAGEMENT REPORT
FOR:
CRESSWIND WESLEY CHAPEL - PHASE 03
WESLEY CHAPEL, NC
PREPARED FOR:
KH WESLEY CHAPEL, LLC
APRIL 1, 2021
THOMAS
& HUTTON
ENGINEERING -
co
No F-0871 0
O %IIIIII1111 �O
Prepared by:
THOMAS Sc HUTTON

STORMWATER MANAGEMENT REPORT
Cresswind Wesley Chapel - Phase 03
Project: Cresswind Wesley Chapel - Phase 03
T&H Job Number: J-27842.0003
Location: Potter Road
Wesley Chapel, NC 28173
Date Prepared: April 1, 2021
Owner: KH Wesley Chapel, LLC
Owner Address: 8913 Silver Springs Court Drive
Charlotte, NC 28215
Engineer: Thomas & Hutton
Engineer Address: 1020 Euclid Avenue
Charlotte, NC 28203
Phone: [phone]
H THOMAS & HUTTON
Page 1

TABLE OF CONTENTS
Section 1 - Summary of Results....................................................................................................... Page 3
Section 2 - Project Narrative...........................................................................................................
Page 4
Section3 - Purpose...........................................................................................................................
Page 4
Section 4 - Regulatory Summary....................................................................................................
Page 5
Section5- Methodology.................................................................................................................Page
5
Section6- Hydrology.......................................................................................................................Page
6
Section 7- Runoff Calculations......................................................................................................Page
6
Section 8- Existing Conditions........................................................................................................Page
8
Section 9 - Post Development Conditions.....................................................................................Page
8
APPENDICES
ProjectMapping......................................................................................................................
Appendix A
Aerial Location Map..........................................................................................................
Exhibit A
FEMAMap...........................................................................................................................
Exhibit B
WetlandsMap....................................................................................................................
Exhibit D
SoilsMap..............................................................................................................................
Exhibit E
Pre Development Drainage Map...........................................................................................Appendix
B
Pre Development Conditions Drainage Calculations.........................................................
Appendix C
Post Development Drainage Map........................................................................................
Appendix D
Post Development Conditions Drainage Calculations........................................................Appendix
E
Water Quality Calculations......................................................................................................
Appendix F
H THOMAS & HUTTON
Page 2

SECTION 1 - SUMMARY OF RESULTS
Table 1 - Pre Development Runoff Rates
TABLE 1
Summary of Results - Existing Conditions
Storm Event
Outfall 01
cfs
2-year
41
10-Year
88
25-Year
114
50-Year
138
Table 2 - Post Development Runoff Rates
TABLE 1
Summary of Results - Proposed Conditions
Storm Event
Outfall 01
cfs
2-year
33
10-Year
78
25-Year
112
50-Year
148
SECTION 2 - PROJECT NARRATIVE
H THOMAS & HUTTON
Page 3

Cresswind is a residential subdivision within Wesley Chapel, North Carolina. Phase 3 consists of
approximately 157 single family detached units, with a portion draining to the exisiting pond in
Phase 2 and the remaining draining to the proposed pond in Phase 3. The site is located in Union
County along Potter Road, north of Newtown Road and south of Weddington Road.
The majority of the site is currently wooded with an understory of brush. Pre -development run-
off is discharged into an existing wetland system and FEMA Floodplain. The pre -development
drainage basins have been delineated and are illustrated on the Pre -Development Drainage
Exhibit found at the end of this report.
For the purpose of this report we will compare the predevelopment runoff rates to the post
development runoff rates as shown in the summary at the beginning of this report. The pre -
development basin SUB-01 will be routed through one wet detention ponds during post
development conditions and outfall into the existing wetlands and floodplain.
The post -development sub -basins were delineated and are illustrated on the Post -Development
Drainage Exhibit found at the end of this report. All design information for ponds and associated
drainage pipes and structures can be found in the appendices of this report.
The soils on this site consist of type B, C and D hydrologic soil groups which are shown on the
attached NRCS soils map within Appendix A.
SECTION 3 - PURPOSE
The purposes of this report are:
1. To delineate all pre -development basins that are within this project and determine
which drainage basins will be affected by the proposed development.
2. To develop a stormwater model that will:
a. Be in compliance with the NCDEQ stormwater regulations.
b. Simulate the pre- and post -development conditions for the project.
c. Predict water elevations for all proposed ponds.
d. Demonstrate that all culverts are of adequate size for drainage under post -
development conditions.
e. Provide design flows (under future build out conditions) for the major drainage
structures that can be used to properly size improvements, if needed.
3. To document that the stormwater management measures and equipment installed
on site will be adequate for all existing and proposed development on the site.
Two drainage models are included in this report;
• Pre -Development: examines the drainage basin prior to any development within the site.
• Post -Development: examines the drainage basin after site improvements have been
installed. The model may need to be revised and updated as the site plan evolves.
H THOMAS & HUTTON
Page 4

SECTION 4 - REGULATORY SUMMARY
NCDEQ - Stormwater
The North Carolina Department of Environmental Quality (NCDEQ) is responsible for
administering the storm water management program.
Development or re -development activities are required to apply for and receive a stormwater
permit from NCDEQ. These permits address water quality and quantity.
NCDEQ regulations require that peak post -development discharge rates from the basin shall be
at or below pre -development rates for the 10 and 25-year storms events. The regulations also
specify the 1-inch volume drawdown shall be released over a time of 48 to 120 hours to minimize
hydrologic impacts to the receiving channel. See attached Exhibit E for post -development peak
flow control calculations, and Exhibit F for water quality calculations.
The stormwater treatment shall be designed to achieve average annual 857o Total Suspended
Solids (TSS) removal and must apply to the volume of post -development runoff resulting from the
one -inch rainfall. See attached Exhibit E for post -development peak flow control calculations,
and Exhibit F for water quality and channel protection calculations.
SECTION 5 - 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
H THOMAS & HUTTON
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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 Storm Sewers 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.
SECTION 6 - HYDROLOGY
■ SCS TR-55 Method was used.
■ The rainfall intensity used for each storm event was obtained from rainfall data publicly
available for Union County, NC. The following design storms are used in the model
simulations:
- 2-year, 6-hour Design Storm =
3.50 inches
- 10-year, 6-hour Design Storm =
5.20 inches
- 25-year, 6-hour Design Storm =
6.10 inches
- 50-year, 6-hour Design Storm =
6.90 inches
- 100-year, 6-hour Design Storm=
7.50 inches
■ SCS Type II Statistical Rainfall Distribution was used. This distribution pattern is determined
by the Soil Conservation Service comparing regional rain -gage data.
■ Soils present on site consist of the following:
- Badin channery silty clay loam, 2 to 8 percent slopes (BdB2) - HSG C
- Chewacla silt loam, 0 to 2 percent slopes (ChA) - HSG B/D
- Goldstone-Badin complex (GsC), 8 to 15 percent slopes - HSG C
- Tarrus gravelly silty clay loam, 2 to 8 percent slopes (TbB2) - HSG B
SECTION 7 - RUNOFF CALCULATIONS
Peak flow rates for the watersheds were calculated by the SSA Program for each design storm. The
pre- and post -development drainage basins are shown in appendicies 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 of Union County, NC provided by The United
H THOMAS & HUTTON
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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:
Sheet Flow: (hr)
0.00 7(n.L) a.s
t1 — Pz 0.05 X S
a.4
Shallow Concentrated Flow: (hr)
L
_
tz 3600 x V
Channel Flow: (hr)
L
i3 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.
Mr.
THOMAS & HUTTON
Page 7

SECTION 8 - EXISTING CONDITIONS
The total acreage of the drainage basins analyzed in the stormwater calculations is
approximately 55 acres. The existing conditions described in this narrative will refer to the pre -
development condition of the site. The pre -development conditions for the site consists
predominantly of woods with an understory of brush.
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 into an existing wetland (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 18 acres. This site maintains all pre -development
discharge points in the post -development condition. Post -development peak flows are less than
pre -development conditions for the 2-yr, 10-yr, and 25-yr storm events. See Appendices B
through H for pre- and post -development SSA model input and results. See Summary of pre -
development versus post -development results at the beginning of report.
After development, the site will consist of approximately 76 single family lots in Phase 2 and 96 lots
in a future phase, public roads, private driveways, and stormwater management features such
as drainage swales and stormwater detention ponds. Stormwater runoff from site will be
conveyed to a proposed wet detention pond. The detention pond will meet NCDEQ pre- and
post -development flows and meet freeboard requirements for the ten (10) year, twenty-five (25)
year, and fifty (50) year storm events.
The proposed detention ponds were designed to meet criteria found in the NCDEQ BMP Design
Manual. Additionally, the required freeboard has been provided beneath the emergency
spillways and the pond embankments for the (50) year storm event. The following tables illustrate
the maximum water surface elevation for the two (2) year, ten (10) year, twenty-five (25) year, and
fifty (50) year storm events both ponds.
H THOMAS & HUTTON
Page 8

Table 3 - Wet Detention Pond 04
Bottom of Pond = 563.5
Crest of Emergency Spillway = 572.75
Top of Embankment = 573.00
Wet Detention Pond 04
Storm Event
Max Elevation
(f0
10-Year
572.49
25-Year
573.04
50-Year
573.27
H THOMAS & HUTTON
Page 9

STORMWATER MANAGEMENT REPORT
CRESSWIND WESLEY CHAPEL - PHASE 03
APPENDIX A
PROJECT MAPPING
27842.0003
H THOMAS Sc HUTTON

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Hydrologic Soil Group —Union County, North Carolina
Hydrologic Soil Group
Map unit symbol
Map unit name
Rating
Acres in AOI
Percent of AOI
2mx85
Badin channery silty
C
52.7
65.2%
clay loam, 2 to 8
percent slopes,
moderately eroded
2mx8q
Tarrus gravelly silty clay
B
3.1
3.9%
loam, 2 to 8 percent
slopes, moderately
eroded
3wOp
Chewacla silt loam, 0 to
B/D
14.3
17.7%
2 percent slopes,
frequently flooded
3w12
Goldston-Badin
D
10.7
13.2%
complex, 8 to 15
percent slopes
Totals for Area of Interest
80.9
100.0%
USDA Natural Resources Web Soil Survey 2/17/2021
Conservation Service National Cooperative Soil Survey Page 3 of 4

Hydrologic Soil Group —Union County, North Carolina
Description
Hydrologic soil groups are based on estimates of runoff potential. Soils are
assigned to one of four groups according to the rate of water infiltration when the
soils are not protected by vegetation, are thoroughly wet, and receive
precipitation from long -duration storms.
The soils in the United States are assigned to four groups (A, B, C, and D) and
three dual classes (A/D, B/D, and C/D). The groups are defined as follows:
Group A. Soils having a high infiltration rate (low runoff potential) when
thoroughly wet. These consist mainly of deep, well drained to excessively
drained sands or gravelly sands. These soils have a high rate of water
transmission.
Group B. Soils having a moderate infiltration rate when thoroughly wet. These
consist chiefly of moderately deep or deep, moderately well drained or well
drained soils that have moderately fine texture to moderately coarse texture.
These soils have a moderate rate of water transmission.
Group C. Soils having a slow infiltration rate when thoroughly wet. These consist
chiefly of soils having a layer that impedes the downward movement of water or
soils of moderately fine texture or fine texture. These soils have a slow rate of
water transmission.
Group D. Soils having a very slow infiltration rate (high runoff potential) when
thoroughly wet. These consist chiefly of clays that have a high shrink -swell
potential, soils that have a high water table, soils that have a claypan or clay
layer at or near the surface, and soils that are shallow over nearly impervious
material. These soils have a very slow rate of water transmission.
If a soil is assigned to a dual hydrologic group (A/D, B/D, or C/D), the first letter is
for drained areas and the second is for undrained areas. Only the soils that in
their natural condition are in group D are assigned to dual classes.
Rating Options
Aggregation Method: Dominant Condition
Component Percent Cutoff.- None Specified
Tie -break Rule: Higher
USDA Natural Resources Web Soil Survey 2/17/2021
Conservation Service National Cooperative Soil Survey Page 4 of 4

STORMWATER MANAGEMENT REPORT
CRESSWIND WESLEY CHAPEL - PHASE 03
APPENDIX B
PRE -DEVELOPMENT DRAINAGE MAP
27842.0003
H THOMAS Sc HUTTON

cV
w
U
oz
w
6
fdF _
OLT
Q r Q
oQ
F=
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Y
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STORMWATER MANAGEMENT REPORT
CRESSWIND WESLEY CHAPEL - PHASE 03
APPENDIX C
PRE -DEVELOPMENT CONDITIONS
DRAINAGE CALCULATIONS
27842.0003
H THOMAS Sc HUTTON

277842.0003
CRESSWIND WESLEY CHAPEL - PHASE 03
PRE -DEVELOPMENT BASINS MODEL

Pre -Development 002 - Year
Project Description
Page 1
File Name .................................................... 27842.0003 - PRE.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 ........................................
Dec 03, 2020
00:00:00
End Analysis On ..........................................
Dec 04, 2020
00:00:00
Start Reporting On ......................................
Dec 03, 2020
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 ......................................
15
seconds
Number of Elements
Qty
RainGages .................................................
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
LandUses ...................................................
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 Union 2 3.50 SCS Type III 24-hr

Pre -Development 002 - Year Page 2
Subbasin Summary
SN Subbasin Area Peak Rate Weighted
Total
Total
Total
Peak
Time of
ID Factor Curve Rainfall Runoff
Runoff
Runoff
Concentration
Number
Volume
(ac)
(in)
(in)
(ac-in)
(cfs)
(days hh:mm:ss)
1 Sub-44 55.11 0.00 73.26
3.50
1.20
65.86
41.21
0 00:31:57

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) (ft2) (cfs) (ft)
(ft)
(ft) (days hh:mm)
(ac-in) (min)
1 Out-21 Outfall 0.00
0.00 0.00

Pre -Development 002 - Year
Subbasin Hydrology
Page 4
Subbasin : Sub-44
Input Data
Area(ac)........................................................................ 55.11
Peak Rate Factor........................................................... 0.00
Weighted Curve Number ............................................... 73.26
RainGage ID.................................................................
Composite Curve Number
Area
Soil
Curve
Soil/Surface Description
(acres)
Group
Number
Pasture, grassland, or range, Good
16.05
D
80.00
Pasture, grassland, or range, Good
28.53
C
74.00
Pasture, grassland, or range, Good
10.53
B
61.00
Composite Area & Weighted CN
55.11
73.26
Time of Concentration
TOC Method : SCS TR-55
Sheet Flow Equation
Tc = (0.007 ' ((n ' Lf)A0.8)) / ((PA0.5) ' (SfA0.4))
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' (SfA0.5) (unpaved surface)
V = 20.3282' (SfA0.5) (paved surface)
V = 15.0' (SfA0.5) (grassed waterway surface)
V = 10.0' (SfA0.5) (nearly bare & untilled surface)
V = 9.0' (SfA0.5) (cultivated straight rows surface)
V = 7.0' (SfA0.5) (short grass pasture surface)
V = 5.0' (SfA0.5) (woodland surface)
V = 2.5 ' (SfA0.5) (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' (RA(2/3))' (SfA0.5)) / 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 (ft2)
Wp
= Wetted Perimeter (ft)
V =
Velocity (ft/sec)
Sf =
Slope (ft/ft)
n =
Manning's roughness

Pre -Development 002 - Year Page 5
Flowpath
Flowpath Flowpath
Sheet Flow Computations
A
B C
Manning's Roughness :
.4
0.00 0.00
Flow Length (ft) :
100
0.00 0.00
Slope (%) :
4
0.00 0.00
2 yr, 24 hr Rainfall (in) :
3.50
0.00 0.00
Velocity (ft/sec) :
0.11
0.00 0.00
Computed Flow Time (min) :
15.56
0.00 0.00
Flowpath
Flowpath Flowpath
Shallow Concentrated Flow Computations
A
B C
Flow Length (ft) :
2460
0.00 0.00
Slope (%) :
2.4
0.00 0.00
Surface Type:
Unpaved
Unpaved Unpaved
Velocity (ft/sec) :
2.50
0.00 0.00
Computed Flow Time (min) :
16.40
0.00 0.00
Total TOC (min) ..................31.96
Subbasin Runoff Results
Total Rainfall (in)............................................................ 3.50
Total Runoff (in)............................................................. 1.20
Peak Runoff (cfs)........................................................... 41.21
Weighted Curve Number ............................................... 73.26
Time of Concentration (days hh:mm:ss) ........................ 0 00:31:58

Pre -Development 002 - Year Page 6
Subbasin : Sub-44
3
2.9
2.8
2.7
2.6
2.5
2.4
2.3
2.2
2.1
2
1.9
1.8
1.7
1.6
co 1.5
E 1.4
� 1.3
1.2
1.1
1
0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
44
42
40
30
36
34
32
30
28
26
N
V �Q
0
22
20
CY
10
16
14
12
10
8
6
4
2
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 010 - Year
Project Description
Page 1
File Name .................................................... 27842.0003 - PRE.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 ........................................
Dec 03, 2020
00:00:00
End Analysis On ..........................................
Dec 04, 2020
00:00:00
Start Reporting On ......................................
Dec 03, 2020
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 ......................................
15
seconds
Number of Elements
Qty
RainGages .................................................
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
LandUses ...................................................
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 Union 10 5.20 SCS Type III 24-hr

Pre -Development 010 - Year Page 2
Subbasin Summary
SN Subbasin Area Peak Rate Weighted Total Total Total Peak Time of
ID Factor Curve Rainfall Runoff Runoff Runoff Concentration
Number Volume
(ac) (in) (in) (ac-in) (cfs) (days hh:mm:ss)
1 Sub-44 55.11 0.00 73.26 5.20 2.46 135.63 88.28 0 00:31:57

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-21 Outfall
0.00
0.00 0.00

Pre -Development 010 - Year
Subbasin Hydrology
Page 4
Subbasin : Sub-44
Input Data
Area(ac)........................................................................ 55.11
Peak Rate Factor........................................................... 0.00
Weighted Curve Number ............................................... 73.26
RainGage ID.................................................................
Composite Curve Number
Area
Soil
Curve
Soil/Surface Description
(acres)
Group
Number
Pasture, grassland, or range, Good
16.05
D
80.00
Pasture, grassland, or range, Good
28.53
C
74.00
Pasture, grassland, or range, Good
10.53
B
61.00
Composite Area & Weighted CN
55.11
73.26
Time of Concentration
TOC Method : SCS TR-55
Sheet Flow Equation
Tc = (0.007 ' ((n ' Lf)A0.8)) / ((PA0.5) ' (SfA0.4))
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' (SfA0.5) (unpaved surface)
V = 20.3282' (SfA0.5) (paved surface)
V = 15.0' (SfA0.5) (grassed waterway surface)
V = 10.0' (SfA0.5) (nearly bare & untilled surface)
V = 9.0' (SfA0.5) (cultivated straight rows surface)
V = 7.0' (SfA0.5) (short grass pasture surface)
V = 5.0' (SfA0.5) (woodland surface)
V = 2.5 ' (SfA0.5) (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' (RA(2/3))' (SfA0.5)) / 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 (ft2)
Wp
= Wetted Perimeter (ft)
V =
Velocity (ft/sec)
Sf =
Slope (ft/ft)
n =
Manning's roughness

Pre -Development 010 - Year Page 5
Flowpath
Flowpath Flowpath
Sheet Flow Computations
A
B C
Manning's Roughness :
.4
0.00 0.00
Flow Length (ft) :
100
0.00 0.00
Slope (%) :
4
0.00 0.00
2 yr, 24 hr Rainfall (in) :
3.50
0.00 0.00
Velocity (ft/sec) :
0.11
0.00 0.00
Computed Flow Time (min) :
15.56
0.00 0.00
Flowpath
Flowpath Flowpath
Shallow Concentrated Flow Computations
A
B C
Flow Length (ft) :
2460
0.00 0.00
Slope (%) :
2.4
0.00 0.00
Surface Type:
Unpaved
Unpaved Unpaved
Velocity (ft/sec) :
2.50
0.00 0.00
Computed Flow Time (min) :
16.40
0.00 0.00
Total TOC (min) ..................31.96
Subbasin Runoff Results
Total Rainfall (in)............................................................ 5.20
Total Runoff (in)............................................................. 2.46
Peak Runoff (cfs)........................................................... 88.28
Weighted Curve Number ............................................... 73.26
Time of Concentration (days hh:mm:ss) ........................ 0 00:31:58

Pre -Development 010 - Year Page 6
Subbasin : Sub-44
4.4
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
95
90
85
80
75
70
65
60
65
60
0 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]

Pre -Development 025 - Year
Project Description
Page 1
File Name .................................................... 27842.0003 - PRE.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 ........................................
Dec 03, 2020
00:00:00
End Analysis On ..........................................
Dec 04, 2020
00:00:00
Start Reporting On ......................................
Dec 03, 2020
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 ......................................
15
seconds
Number of Elements
Qty
RainGages .................................................
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
LandUses ...................................................
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 Union 25 6.10 SCS Type III 24-hr

Pre -Development 025 - Year Page 2
Subbasin Summary
SN Subbasin Area Peak Rate Weighted Total Total Total Peak Time of
ID Factor Curve Rainfall Runoff Runoff Runoff Concentration
Number Volume
(ac) (in) (in) (ac-in) (cfs) (days hh:mm:ss)
1 Sub-44 55.11 0.00 73.26 6.10 3.20 176.19 115.31 0 00:31:57

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-21 Outfall
0.00
0.00 0.00

Pre -Development 025 - Year
Subbasin Hydrology
Page 4
Subbasin : Sub-44
Input Data
Area(ac)........................................................................ 55.11
Peak Rate Factor........................................................... 0.00
Weighted Curve Number ............................................... 73.26
RainGage ID.................................................................
Composite Curve Number
Area
Soil
Curve
Soil/Surface Description
(acres)
Group
Number
Pasture, grassland, or range, Good
16.05
D
80.00
Pasture, grassland, or range, Good
28.53
C
74.00
Pasture, grassland, or range, Good
10.53
B
61.00
Composite Area & Weighted CN
55.11
73.26
Time of Concentration
TOC Method : SCS TR-55
Sheet Flow Equation
Tc = (0.007 ' ((n ' Lf)A0.8)) / ((PA0.5) ' (SfA0.4))
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' (SfA0.5) (unpaved surface)
V = 20.3282' (SfA0.5) (paved surface)
V = 15.0' (SfA0.5) (grassed waterway surface)
V = 10.0' (SfA0.5) (nearly bare & untilled surface)
V = 9.0' (SfA0.5) (cultivated straight rows surface)
V = 7.0' (SfA0.5) (short grass pasture surface)
V = 5.0' (SfA0.5) (woodland surface)
V = 2.5 ' (SfA0.5) (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' (RA(2/3))' (SfA0.5)) / 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 (ft2)
Wp
= Wetted Perimeter (ft)
V =
Velocity (ft/sec)
Sf =
Slope (ft/ft)
n =
Manning's roughness

Pre -Development 025 - Year Page 5
Flowpath
Flowpath Flowpath
Sheet Flow Computations
A
B C
Manning's Roughness :
.4
0.00 0.00
Flow Length (ft) :
100
0.00 0.00
Slope (%) :
4
0.00 0.00
2 yr, 24 hr Rainfall (in) :
3.50
0.00 0.00
Velocity (ft/sec) :
0.11
0.00 0.00
Computed Flow Time (min) :
15.56
0.00 0.00
Flowpath
Flowpath Flowpath
Shallow Concentrated Flow Computations
A
B C
Flow Length (ft) :
2460
0.00 0.00
Slope (%) :
2.4
0.00 0.00
Surface Type:
Unpaved
Unpaved Unpaved
Velocity (ft/sec) :
2.50
0.00 0.00
Computed Flow Time (min) :
16.40
0.00 0.00
Total TOC (min) ..................31.96
Subbasin Runoff Results
Total Rainfall (in)............................................................ 6.10
Total Runoff (in)............................................................. 3.20
Peak Runoff (cfs)........................................................... 115.31
Weighted Curve Number ............................................... 73.26
Time of Concentration (days hh:mm:ss) ........................ 0 00:31:58

Pre -Development 025 - Year Page 6
Subbasin : Sub-44
5.2
5
4.8
4.6
4.4
4.2
4
3.8
3.6
3.4
3.2
3
E 2.8
2.6
'E 2.4
2.2
2
1.8
1.6
1.4
1.2
1
0.8
0.6
0.4
0.2
120
115
110
105
100
95
90
85
80
75
70
65
0
60
65
60
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 8 J 8 9 10 11 12 13 14 15 18 I 18 19 20 21 22 23
Time [hrs]

Pre -Development 050 - Year
Project Description
Page 1
File Name .................................................... 27842.0003 - PRE.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 ........................................
Dec 03, 2020
00:00:00
End Analysis On ..........................................
Dec 04, 2020
00:00:00
Start Reporting On ......................................
Dec 03, 2020
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 ......................................
15
seconds
Number of Elements
Qty
RainGages .................................................
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
LandUses ...................................................
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 Union 50 6.90 SCS Type III 24-hr

Pre -Development 050 - Year Page 2
Subbasin Summary
SN Subbasin Area Peak Rate Weighted
Total
Total
Total Peak
Time of
ID Factor Curve Rainfall Runoff
Runoff Runoff
Concentration
Number
Volume
(ac)
(in)
(in)
(ac-in) (cfs)
(days hh:mm:ss)
1 Sub-44 55.11 0.00 73.26
6.90
3.88
213.66 139.90
0 00:31:57

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-21 Outfall 0.00
0.00 0.00

Pre -Development 050 - Year
Subbasin Hydrology
Page 4
Subbasin : Sub-44
Input Data
Area(ac)........................................................................ 55.11
Peak Rate Factor........................................................... 0.00
Weighted Curve Number ............................................... 73.26
RainGage ID.................................................................
Composite Curve Number
Area
Soil
Curve
Soil/Surface Description
(acres)
Group
Number
Pasture, grassland, or range, Good
16.05
D
80.00
Pasture, grassland, or range, Good
28.53
C
74.00
Pasture, grassland, or range, Good
10.53
B
61.00
Composite Area & Weighted CN
55.11
73.26
Time of Concentration
TOC Method : SCS TR-55
Sheet Flow Equation
Tc = (0.007 ' ((n ' Lf)A0.8)) / ((PA0.5) ' (SfA0.4))
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' (SfA0.5) (unpaved surface)
V = 20.3282' (SfA0.5) (paved surface)
V = 15.0' (SfA0.5) (grassed waterway surface)
V = 10.0' (SfA0.5) (nearly bare & untilled surface)
V = 9.0' (SfA0.5) (cultivated straight rows surface)
V = 7.0' (SfA0.5) (short grass pasture surface)
V = 5.0' (SfA0.5) (woodland surface)
V = 2.5 ' (SfA0.5) (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' (RA(2/3))' (SfA0.5)) / 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 (ft2)
Wp
= Wetted Perimeter (ft)
V =
Velocity (ft/sec)
Sf =
Slope (ft/ft)
n =
Manning's roughness

Pre -Development 050 - Year Page 5
Flowpath
Flowpath Flowpath
Sheet Flow Computations
A
B C
Manning's Roughness :
.4
0.00 0.00
Flow Length (ft) :
100
0.00 0.00
Slope (%) :
4
0.00 0.00
2 yr, 24 hr Rainfall (in) :
3.50
0.00 0.00
Velocity (ft/sec) :
0.11
0.00 0.00
Computed Flow Time (min) :
15.56
0.00 0.00
Flowpath
Flowpath Flowpath
Shallow Concentrated Flow Computations
A
B C
Flow Length (ft) :
2460
0.00 0.00
Slope (%) :
2.4
0.00 0.00
Surface Type:
Unpaved
Unpaved Unpaved
Velocity (ft/sec) :
2.50
0.00 0.00
Computed Flow Time (min) :
16.40
0.00 0.00
Total TOC (min) ..................31.96
Subbasin Runoff Results
Total Rainfall (in)............................................................ 6.90
Total Runoff (in)............................................................. 3.88
Peak Runoff (cfs)........................................................... 139.90
Weighted Curve Number ............................................... 73.26
Time of Concentration (days hh:mm:ss) ........................ 0 00:31:58

Pre -Development 050 - Year Page 6
Subbasin : Sub-44
6
5.8
5.6
5.4
5.2
5
4.0
4.6
4.4
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
145
140
135
130
125
120
115
110
105
100
95
90
_ 85
N 80
T5
o TO
65
fy
60
55
50
45
40
35
3n
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
CRESSWIND WESLEY CHAPEL - PHASE 03
APPENDIX D
POST -DEVELOPMENT
DRAINAGE MAP
m: . oZlZsk3
A THOMAS Sc HUTTON

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STORMWATER MANAGEMENT REPORT
CRESSWIND WESLEY CHAPEL - PHASE 03
APPENDIX E
POST -DEVELOPMENT CONDITIONS
DRAINAGE CALCULATIONS
A THOMAS Sc HUTTON

277842.0003
CRESSWIND WESLEY CHAPEL - PHASE 03
POST -DEVELOPMENT BASINS MODEL

Post -Development 002 - Year
Project Description
Page 1
File Name .................................................... 27842.003 - POST.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 ........................................
Dec 03, 2020
00:00:00
End Analysis On ..........................................
Dec 04, 2020
00:00:00
Start Reporting On ......................................
Dec 03, 2020
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 ......................................
15
seconds
Number of Elements
Qty
RainGages .................................................
1
Subbasins....................................................
2
Nodes...........................................................
4
Junctions ............................................
1
Outfalls...............................................
2
Flow Diversions ..................................
0
Inlets...................................................
0
Storage Nodes ...................................
1
Links.............................................................
5
Channels ............................................
0
Pipes...................................................
1
Pumps................................................
0
Orifices...............................................
2
Weirs..................................................
2
Outlets................................................
0
Pollutants....................................................
0
LandUses ...................................................
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 Union 2 3.50 SCS Type III 24-hr

Post -Development 002 - Year Page 2
Subbasin Summary
SN Subbasin
Area Peak Rate Weighted
Total
Total
Total
Peak
Time of
ID
Factor Curve Rainfall
Runoff
Runoff
Runoff
Concentration
Number
Volume
(ac)
(in)
(in)
(ac-in)
(cfs)
(days hh:mm:ss)
1 Sub-47
37.02 0.00 73.00
3.50
1.18
43.68
27.29
0 003200
2 Sub-48
19.86 0.00 86.19
3.50
2.11
41.98
43.45
0 00:05:00

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)
(ft2) (cfs) (ft)
(ft)
(ft)
(days hh:mm) (ac-in)
(min)
1 CONTROL -STRUCTURE Junction
568.00
573.00
0.00 0.00
1.00 6.45 569.27
0.00
7.23
0 0000 0.00
0.00
2 Emergency-Outffall
Outfall
560.00
0.00 560.00
3 Out-02
Outfall
560.00
32.87 560.00
4 Pond-04
Storage Node
564.50
573.50
568.00
1.00 42.76 571.02
0.00
0.00

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Post -Development 002 - Year Page 5
Subbasin Hydrology
Subbasin : Sub-47
Input Data
Area(ac)........................................................................
37.02
Peak Rate Factor...........................................................
0.00
Weighted Curve Number ...............................................
73.00
RainGage ID.................................................................
Composite Curve Number
Area Soil Curve
Soil/Surface Description
(acres) Group Number
37.02 73.00
Composite Area & Weighted CN
37.02 73.00
Time of Concentration
TOC Method : SCS TR-55
Sheet Flow Equation
Tc = (0.007 ' ((n ' Lf)A0.8)) / ((PAO.5) ' (SfA0.4))
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' (SfA0.5) (unpaved surface)
V = 20.3282' (SfA0.5) (paved surface)
V = 15.0' (SfA0.5) (grassed waterway surface)
V = 10.0' (SfA0.5) (nearly bare & untilled surface)
V = 9.0' (SfA0.5) (cultivated straight rows surface)
V = 7.0' (SfA0.5) (short grass pasture surface)
V = 5.0' (SfA0.5) (woodland surface)
V = 2.5 ' (SfA0.5) (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' (RA(2/3))(SfA0.5)) / 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 (ft2)
Wp = Wetted Perimeter (ft)
V = Velocity (ft/sec)
Sf = Slope (ft/ft)
n = Manning's roughness
User -Defined TOC override (minutes): 32
Subbasin Runoff Results
Total Rainfall (in)............................................................ 3.50
Total Runoff (in)............................................................. 1.18
Peak Runoff (cfs)........................................................... 27.29
Weighted Curve Number ............................................... 73.00
Time of Concentration (days hh:mm:ss) ........................ 0003200

Post -Development 002 - Year Page 6
Subbasin : Sub-47
3
2.9
2.8
2.7
2.6
2.5
2.4
2.3
2.2
2.1
2
1.9
1.8
1.7
1.6
1.5
0 1.4
1.3
1.2
1.1
1
0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
29
28
27
26
25
24
23
22
21
20
19
18
_ 17
16
15
0 14
13
12
11
10
9
8
7
6
5
4
3
2
1
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 6 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23
Time (hrs)

Post -Development 002 - Year
Subbasin : Sub-48
Page 7
Input Data
Area(ac)........................................................................ 19.86
Peak Rate Factor........................................................... 0.00
Weighted Curve Number ............................................... 86.19
RainGage ID.................................................................
Composite Curve Number
Area
Soil
Curve
Soil/Surface Description
(acres)
Group
Number
> 75 % grass cover, Good
6.34
B
61.00
Paved parking & roofs
8.38
A
98.00
Paved parking & roofs
2.09
A
98.00
Paved roads with curbs & sewers
0.71
C
98.00
Paved roads with curbs & sewers
2.06
C
98.00
Paved roads with curbs & sewers
0.28
C
98.00
Composite Area & Weighted CN
19.86
86.19
Time of Concentration
User -Defined TOC override (minutes): 5
Subbasin Runoff Results
Total Rainfall (in)............................................................ 3.50
Total Runoff (in)............................................................. 2.11
Peak Runoff (cfs)........................................................... 43.45
Weighted Curve Number ............................................... 86.19
Time of Concentration (days hh:mm:ss) ........................ 0000500

Post -Development 002 - Year Page 8
Subbasin : Sub-48
3.1
3
2.9
2.8
2.7
2.6
2.5
2.4
2.3
2.2
2.1
2
1.9
1.8
1.7
1.6
1.5
1.4
1.3
1.2
1.1
1
0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
46
44
42
40
38
36
34
32
30
28
n 26
-- 24
0 22
20
18
16
14
12
10
8
6
4
2
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 6 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23
Time (hrs)

Post -Development 002 - Year Page 9
Pipe Input
SN Element Length Inlet Inlet Outlet Outlet Total Average Pipe
ID Invert Invert Invert Invert Drop Slope Shape
Pipe Pipe Manning's Entrance Exit/Bend Additional Initial Flap No. of
Diameter or Width Roughness Losses Losses Losses Flow Gate Barrels
Elevation Offset Elevation Offset Height
(ft) (ft) (ft) (ft) (ft) (ft) N (in) (in) (cfs)
1 Outlet -Pipe 95.00 568.00 8.00 567.00 -1.00 1.00 1.0500 CIRCULAR 36.000 36.000 0.0150 0.5000 0.5000 0.0000 0.00 No 1

Post -Development 002 - Year Page 10
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 Outlet -Pipe 6.45 0 12:44 1.88 3.44 3.00 0.53 1.03 0.34 0.00 > CAPACITY

Post -Development 002 - Year Page 11
Storage Nodes
Storage Node : Pond-04
Input Data
Invert Elevation (ft)....................................................................
564.50
Max (Rim) Elevation (ft)............................................................
573.50
Max (Rim) Offset (ft)..................................................................
9.00
Initial Water Elevation (ft)..........................................................
568.00
Initial Water Depth (ft)...............................................................
3.50
Ponded Area (ft2).......................................................................
1.00
Evaporation Loss.......................................................................
0.00
Outflow Weirs
Outflow Orifices
SN Element
Weir Flap
Crest
Crest
Length
Weir Total Discharge
ID
Type Gate
Elevation
Offset
Height Coefficient
(ft)
(ft)
(ft)
(ft)
1 Spillway-04
Trapezoidal No
572.75
8.25
20.00
1.00 3.33
2 Weir-04
Rectangular No
570.00
5.50
2.00
3.00 3.33
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 CS -RIM Bottom
Rectangular
No
60.00
60.00
573.00 0.63
2 WQ-Orifice-04 Side
CIRCULAR
No
3.00
568.00 0.61
Output Summary Results
Peak Inflow (cfs)........................................................................
42.76
Peak Lateral Inflow (cfs)............................................................
42.76
Peak Outflow (cfs).....................................................................
6.45
Peak Exfiltration Flow Rate (cfm)..............................................
0.00
Max HGL Elevation Attained (ft)................................................
571.02
Max HGL Depth Attained (ft).....................................................
6.52
Average HGL Elevation Attained (ft).........................................
569.37
Average HGL Depth Attained (ft)..............................................
4.87
Time of Max HGL Occurrence (days hh:mm) ............................
0 1244
Total Exfiltration Volume (1000-ft')...........................................
0.000
Total Flooded Volume (ac-in)....................................................
0
Total Time Flooded (min)..........................................................
0
Total Retention Time (sec) ........................................................
0.00

Post -Development 010 - Year
Project Description
Page 1
File Name .................................................... 27842.003 - POST.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 ........................................
Dec 03, 2020
00:00:00
End Analysis On ..........................................
Dec 04, 2020
00:00:00
Start Reporting On ......................................
Dec 03, 2020
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 ......................................
15
seconds
Number of Elements
Qty
RainGages .................................................
1
Subbasins....................................................
2
Nodes...........................................................
4
Junctions ............................................
1
Outfalls...............................................
2
Flow Diversions ..................................
0
Inlets...................................................
0
Storage Nodes ...................................
1
Links.............................................................
5
Channels ............................................
0
Pipes...................................................
1
Pumps................................................
0
Orifices...............................................
2
Weirs..................................................
2
Outlets................................................
0
Pollutants....................................................
0
LandUses ...................................................
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 Union 10 5.20 SCS Type III 24-hr

Post -Development 010 - Year Page 2
Subbasin Summary
SN Subbasin
Area Peak Rate Weighted
Total
Total
Total
Peak
Time of
ID
Factor Curve Rainfall
Runoff
Runoff
Runoff
Concentration
Number
Volume
(ac)
(in)
(in)
(ac-in)
(cfs)
(days hh:mm:ss)
1 Sub-47
37.02 0.00 73.00
5.20
2.44
90.25
58.71
0 003200
2 Sub-48
19.86 0.00 86.19
5.20
3.67
72.95
73.51
0 00:05:00

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 CONTROL -STRUCTURE Junction
568.00
573.00
0.00 0.00
1.00 19.83 570.22
0.00
6.28
0 0000 0.00
0.00
2 Emergency-Outffall
Outfall
560.00
0.00 560.00
3 Out-02
Outfall
560.00
78.07 560.00
4 Pond-04
Storage Node
564.50
573.50
568.00
1.00 72.73 572.49
0.00
0.00

Y 0
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Lo Lo Lo Lo
L° L° L° L°
W W W
Ir 01 ry
D D
H H H
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Post -Development 010 - Year Page 5
Subbasin Hydrology
Subbasin : Sub-47
Input Data
Area(ac)........................................................................
37.02
Peak Rate Factor...........................................................
0.00
Weighted Curve Number ...............................................
73.00
RainGage ID.................................................................
Composite Curve Number
Area Soil Curve
Soil/Surface Description
(acres) Group Number
37.02 73.00
Composite Area & Weighted CN
37.02 73.00
Time of Concentration
TOC Method : SCS TR-55
Sheet Flow Equation
Tc = (0.007 ' ((n ' Lf)A0.8)) / ((PAO.5) ' (SfA0.4))
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' (SfA0.5) (unpaved surface)
V = 20.3282' (SfA0.5) (paved surface)
V = 15.0' (SfA0.5) (grassed waterway surface)
V = 10.0' (SfA0.5) (nearly bare & untilled surface)
V = 9.0' (SfA0.5) (cultivated straight rows surface)
V = 7.0' (SfA0.5) (short grass pasture surface)
V = 5.0' (SfA0.5) (woodland surface)
V = 2.5 ' (SfA0.5) (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' (RA(2/3))(SfA0.5)) / 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 (ft2)
Wp = Wetted Perimeter (ft)
V = Velocity (ft/sec)
Sf = Slope (ft/ft)
n = Manning's roughness
User -Defined TOC override (minutes): 32
Subbasin Runoff Results
Total Rainfall (in)............................................................ 5.20
Total Runoff (in)............................................................. 2.44
Peak Runoff (cfs)........................................................... 58.71
Weighted Curve Number ............................................... 73.00
Time of Concentration (days hh:mm:ss) ........................ 0003200

Post -Development 010 - Year Page 6
Subbasin : Sub-47
4.4
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
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
62
60
58
56
54
52
50
48
46
44
42
40
38
36
34
32
0 30
� 28
26
24
22---
20---
18-
16-
0 1 2 3 4 6 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23
Time (hrs)

Post -Development 010 - Year
Subbasin : Sub-48
Page 7
Input Data
Area(ac)........................................................................ 19.86
Peak Rate Factor........................................................... 0.00
Weighted Curve Number ............................................... 86.19
RainGage ID.................................................................
Composite Curve Number
Area
Soil
Curve
Soil/Surface Description
(acres)
Group
Number
> 75 % grass cover, Good
6.34
B
61.00
Paved parking & roofs
8.38
A
98.00
Paved parking & roofs
2.09
A
98.00
Paved roads with curbs & sewers
0.71
C
98.00
Paved roads with curbs & sewers
2.06
C
98.00
Paved roads with curbs & sewers
0.28
C
98.00
Composite Area & Weighted CN
19.86
86.19
Time of Concentration
User -Defined TOC override (minutes): 5
Subbasin Runoff Results
Total Rainfall (in)............................................................ 5.20
Total Runoff (in)............................................................. 3.67
Peak Runoff (cfs)........................................................... 73.51
Weighted Curve Number ............................................... 86.19
Time of Concentration (days hh:mm:ss) ........................ 0000500

Post -Development 010 - Year Page 8
Subbasin : Sub-48
4.6
4.4
4.2
4
3.8
3.6
3.4
3.2
3
2.8
2.6
2.4
2 2.2
M 2
0
1.8
1.6
1.4
1.2
1
0.8
0.6
0.4
0.2
80
75
70
65
60
55
50
n 45
40
0
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 6 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23
Time (hrs)

Post -Development 010 - Year Page 9
Pipe Input
SN Element Length Inlet Inlet Outlet Outlet Total Average Pipe
ID Invert Invert Invert Invert Drop Slope Shape
Pipe Pipe Manning's Entrance Exit/Bend Additional Initial Flap No. of
Diameter or Width Roughness Losses Losses Losses Flow Gate Barrels
Elevation Offset Elevation Offset Height
(ft) (ft) (ft) (ft) (ft) (ft) N (in) (in) (cfs)
1 Outlet -Pipe 95.00 568.00 8.00 567.00 -1.00 1.00 1.0500 CIRCULAR 36.000 36.000 0.0150 0.5000 0.5000 0.0000 0.00 No 1

Post -Development 010 - Year Page 10
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 Outlet -Pipe 19.83 0 12:32 1.88 10.57 4.41 0.36 1.82 0.61 0.00 > CAPACITY

Post -Development 010 - Year Page 11
Storage Nodes
Storage Node : Pond-04
Input Data
Invert Elevation (ft)....................................................................
564.50
Max (Rim) Elevation (ft)............................................................
573.50
Max (Rim) Offset (ft)..................................................................
9.00
Initial Water Elevation (ft)..........................................................
568.00
Initial Water Depth (ft)...............................................................
3.50
Ponded Area (ft2).......................................................................
1.00
Evaporation Loss.......................................................................
0.00
Outflow Weirs
Outflow Orifices
SN Element
Weir Flap
Crest
Crest
Length
Weir Total Discharge
ID
Type Gate
Elevation
Offset
Height Coefficient
(ft)
(ft)
(ft)
(ft)
1 Spillway-04
Trapezoidal No
572.75
8.25
20.00
1.00 3.33
2 Weir-04
Rectangular No
570.00
5.50
2.00
3.00 3.33
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 CS -RIM Bottom
Rectangular
No
60.00
60.00
573.00 0.63
2 WQ-Orifice-04 Side
CIRCULAR
No
3.00
568.00 0.61
Output Summary Results
Peak Inflow (cfs)........................................................................
72.73
Peak Lateral Inflow (cfs)............................................................
72.73
Peak Outflow (cfs).....................................................................
19.83
Peak Exfiltration Flow Rate (cfm)..............................................
0.00
Max HGL Elevation Attained (ft)................................................
572.49
Max HGL Depth Attained (ft).....................................................
7.99
Average HGL Elevation Attained (ft).........................................
569.79
Average HGL Depth Attained (ft)..............................................
5.29
Time of Max HGL Occurrence (days hh:mm) ............................
0 1232
Total Exfiltration Volume (1000-ft')...........................................
0.000
Total Flooded Volume (ac-in)....................................................
0
Total Time Flooded (min)..........................................................
0
Total Retention Time (sec) ........................................................
0.00

Post -Development 025 - Year
Project Description
Page 1
File Name .................................................... 27842.003 - POST.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 ........................................
Dec 03, 2020
00:00:00
End Analysis On ..........................................
Dec 04, 2020
00:00:00
Start Reporting On ......................................
Dec 03, 2020
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 ......................................
15
seconds
Number of Elements
Qty
RainGages .................................................
1
Subbasins....................................................
2
Nodes...........................................................
4
Junctions ............................................
1
Outfalls...............................................
2
Flow Diversions ..................................
0
Inlets...................................................
0
Storage Nodes ...................................
1
Links.............................................................
5
Channels ............................................
0
Pipes...................................................
1
Pumps................................................
0
Orifices...............................................
2
Weirs..................................................
2
Outlets................................................
0
Pollutants....................................................
0
LandUses ...................................................
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 Union 25 6.10 SCS Type III 24-hr

Post -Development 025 - Year Page 2
Subbasin Summary
SN Subbasin
Area Peak Rate Weighted
Total
Total
Total
Peak
Time of
ID
Factor Curve Rainfall
Runoff
Runoff
Runoff
Concentration
Number
Volume
(ac)
(in)
(in)
(ac-in)
(cfs)
(days hh:mm:ss)
1 Sub-47
37.02 0.00 73.00
6.10
3.17
117.43
76.85
0 003200
2 Sub-48
19.86 0.00 86.19
6.10
4.53
89.87
89.43
0 00:05:00

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 CONTROL -STRUCTURE Junction
568.00
573.00
0.00 0.00
1.00
25.57 570.56
0.00
5.94
0 0000 0.00
0.00
2 Emergency-Outffall
Outfall
560.00
10.71 560.00
3 Out-02
Outfall
560.00
101.24 560.00
4 Pond-04
Storage Node
564.50
573.50
568.00
1.00
88.66 573.04
0.00
0.00

Y 0
� O
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C
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O L
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0 0
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a
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C
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E °
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C
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E
O E
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a Y zn
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0 0 o v
N
O 00
00
O M
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0000
0000
CO CO O CO
O O O O
Lo Lo Lo Lo
0000
Lo Lo Lo Lo
V V V V
Lo Lo Lo Lo
L° L° L° L°
W W W
Ir 01 ry
D D
H H H
O O - O
S S S
ry
O �
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O O C O
d d N d'
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0 0 0 0
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a aaa

Post -Development 025 - Year Page 5
Subbasin Hydrology
Subbasin : Sub-47
Input Data
Area(ac)........................................................................
37.02
Peak Rate Factor...........................................................
0.00
Weighted Curve Number ...............................................
73.00
RainGage ID.................................................................
Composite Curve Number
Area Soil Curve
Soil/Surface Description
(acres) Group Number
37.02 73.00
Composite Area & Weighted CN
37.02 73.00
Time of Concentration
TOC Method : SCS TR-55
Sheet Flow Equation
Tc = (0.007 ' ((n ' Lf)A0.8)) / ((PAO.5) ' (SfA0.4))
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' (SfA0.5) (unpaved surface)
V = 20.3282' (SfA0.5) (paved surface)
V = 15.0' (SfA0.5) (grassed waterway surface)
V = 10.0' (SfA0.5) (nearly bare & untilled surface)
V = 9.0' (SfA0.5) (cultivated straight rows surface)
V = 7.0' (SfA0.5) (short grass pasture surface)
V = 5.0' (SfA0.5) (woodland surface)
V = 2.5 ' (SfA0.5) (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' (RA(2/3))(SfA0.5)) / 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 (ft2)
Wp = Wetted Perimeter (ft)
V = Velocity (ft/sec)
Sf = Slope (ft/ft)
n = Manning's roughness
User -Defined TOC override (minutes): 32
Subbasin Runoff Results
Total Rainfall (in)............................................................ 6.10
Total Runoff (in)............................................................. 3.17
Peak Runoff (cfs)........................................................... 76.85
Weighted Curve Number ............................................... 73.00
Time of Concentration (days hh:mm:ss) ........................ 0003200

Post -Development 025 - Year Page 6
Subbasin : Sub-47
5.2
5
4.8
4.6
4.4
4.2
4
3.8
3.6
3.4
3.2
3
E 2.8
2.6
'E 2.4
2.2
2
1.8
1.6
1.4
1.2
1
0.8
0.6
0.4
0.2
85
80
75
70
65
60
55
50
45
40
o✓
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 6 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23
Time (hrs)

Post -Development 025 - Year
Subbasin : Sub-48
Page 7
Input Data
Area(ac)........................................................................ 19.86
Peak Rate Factor........................................................... 0.00
Weighted Curve Number ............................................... 86.19
RainGage ID.................................................................
Composite Curve Number
Area
Soil
Curve
Soil/Surface Description
(acres)
Group
Number
> 75 % grass cover, Good
6.34
B
61.00
Paved parking & roofs
8.38
A
98.00
Paved parking & roofs
2.09
A
98.00
Paved roads with curbs & sewers
0.71
C
98.00
Paved roads with curbs & sewers
2.06
C
98.00
Paved roads with curbs & sewers
0.28
C
98.00
Composite Area & Weighted CN
19.86
86.19
Time of Concentration
User -Defined TOC override (minutes): 5
Subbasin Runoff Results
Total Rainfall (in)............................................................ 6.10
Total Runoff (in)............................................................. 4.53
Peak Runoff (cfs)........................................................... 89.43
Weighted Curve Number ............................................... 86.19
Time of Concentration (days hh:mm:ss) ........................ 0000500

Post -Development 025 - Year Page 8
Subbasin : Sub-48
5.4
5.2
5
4.8
4.6
4.4
4.2
4
3.8
3.6
3.4
3.2
3
28
m 2.6
F, 2.4
2.2
2
1.8
1.6
1.4
1.2
1
0.8
0.6
0.4
0.2
95
90
85
80
75
70
65
60
55
50
0 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)

Post -Development 025 - Year Page 9
Pipe Input
SN Element Length Inlet Inlet Outlet Outlet Total Average Pipe
ID Invert Invert Invert Invert Drop Slope Shape
Pipe Pipe Manning's Entrance Exit/Bend Additional Initial Flap No. of
Diameter or Width Roughness Losses Losses Losses Flow Gate Barrels
Elevation Offset Elevation Offset Height
(ft) (ft) (ft) (ft) (ft) (ft) N (in) (in) (cfs)
1 Outlet -Pipe 95.00 568.00 8.00 567.00 -1.00 1.00 1.0500 CIRCULAR 36.000 36.000 0.0150 0.5000 0.5000 0.0000 0.00 No 1

Post -Development 025 - Year Page 10
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 Outlet -Pipe 25.57 0 12:25 1.88 13.63 4.85 0.33 2.09 0.70 0.00 > CAPACITY

Post -Development 025 - Year Page 11
Storage Nodes
Storage Node : Pond-04
Input Data
Invert Elevation (ft)....................................................................
564.50
Max (Rim) Elevation (ft)............................................................
573.50
Max (Rim) Offset (ft)..................................................................
9.00
Initial Water Elevation (ft)..........................................................
568.00
Initial Water Depth (ft)...............................................................
3.50
Ponded Area (ft2).......................................................................
1.00
Evaporation Loss.......................................................................
0.00
Outflow Weirs
Outflow Orifices
SN Element
Weir Flap
Crest
Crest
Length
Weir Total Discharge
ID
Type Gate
Elevation
Offset
Height Coefficient
(ft)
(ft)
(ft)
(ft)
1 Spillway-04
Trapezoidal No
572.75
8.25
20.00
1.00 3.33
2 Weir-04
Rectangular No
570.00
5.50
2.00
3.00 3.33
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 CS -RIM Bottom
Rectangular
No
60.00
60.00
573.00 0.63
2 WQ-Orifice-04 Side
CIRCULAR
No
3.00
568.00 0.61
Output Summary Results
Peak Inflow (cfs)........................................................................
88.66
Peak Lateral Inflow (cfs)............................................................
88.66
Peak Outflow (cfs).....................................................................
36.28
Peak Exfiltration Flow Rate (cfm)..............................................
0.00
Max HGL Elevation Attained (ft)................................................
573.04
Max HGL Depth Attained (ft).....................................................
8.54
Average HGL Elevation Attained (ft).........................................
569.98
Average HGL Depth Attained (ft)..............................................
5.48
Time of Max HGL Occurrence (days hh:mm) ............................
0 1225
Total Exfiltration Volume (1000-ft')...........................................
0.000
Total Flooded Volume (ac-in)....................................................
0
Total Time Flooded (min)..........................................................
0
Total Retention Time (sec) ........................................................
0.00

Post -Development 050 - Year
Project Description
Page 1
File Name .................................................... 27842.003 - POST.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 ........................................
Dec 03, 2020
00:00:00
End Analysis On ..........................................
Dec 04, 2020
00:00:00
Start Reporting On ......................................
Dec 03, 2020
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 ......................................
15
seconds
Number of Elements
Qty
RainGages .................................................
1
Subbasins....................................................
2
Nodes...........................................................
4
Junctions ............................................
1
Outfalls...............................................
2
Flow Diversions ..................................
0
Inlets...................................................
0
Storage Nodes ...................................
1
Links.............................................................
5
Channels ............................................
0
Pipes...................................................
1
Pumps................................................
0
Orifices...............................................
2
Weirs..................................................
2
Outlets................................................
0
Pollutants....................................................
0
LandUses ...................................................
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 Union 50 6.90 SCS Type III 24-hr

Post -Development 050 - Year Page 2
Subbasin Summary
SN Subbasin
Area Peak Rate Weighted
Total
Total
Total Peak
Time of
ID
Factor Curve Rainfall
Runoff
Runoff Runoff
Concentration
Number
Volume
(ac)
(in)
(in)
(ac-in) (cfs)
(days hh:mm:ss)
1 Sub-47
37.02 0.00 73.00
6.90
3.85
142.49 93.34
0 003200
2 Sub-48
19.86 0.00 86.19
6.90
5.29
105.08 103.58
0 00:05:00

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 CONTROL -STRUCTURE Junction
568.00
573.00
0.00 0.00
1.00
35.86 571.15
0.00
5.35
0 0000 0.00
0.00
2 Emergency-Outffall
Outfall
560.00
25.19 560.00
3 Out-02
Outfall
560.00
123.29 560.00
4 Pond-04
Storage Node
564.50
573.50
568.00
1.00
102.77 573.27
0.00
0.00

N
r
0
O
Y 0
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C
ry
O L
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NS
E
m
N
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a
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a
2 C O
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C
N
E °
o �
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C
N
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3 U
o in W
a Y zn
J
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N M M
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N N
O 00
00
O M
O
0000
0000
CO CO O CO
O O O O
Lo Lo Lo Lo
0000
Lo Lo Lo Lo
V V V V
Lo Lo Lo Lo
L° L° L° L°
W W W
Ir 01 ry
D D
H H H
O O - O
S S S
ry
O �
T
O O C O
d d N d'
zz Nz O
00 E O
O O W O
v v v v
0 0 0 0
a a a a
O O O O
a aaa

Post -Development 050 - Year Page 5
Subbasin Hydrology
Subbasin : Sub-47
Input Data
Area(ac)........................................................................
37.02
Peak Rate Factor...........................................................
0.00
Weighted Curve Number ...............................................
73.00
RainGage ID.................................................................
Composite Curve Number
Area Soil Curve
Soil/Surface Description
(acres) Group Number
37.02 73.00
Composite Area & Weighted CN
37.02 73.00
Time of Concentration
TOC Method : SCS TR-55
Sheet Flow Equation
Tc = (0.007 ' ((n ' Lf)A0.8)) / ((PAO.5) ' (SfA0.4))
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' (SfA0.5) (unpaved surface)
V = 20.3282' (SfA0.5) (paved surface)
V = 15.0' (SfA0.5) (grassed waterway surface)
V = 10.0' (SfA0.5) (nearly bare & untilled surface)
V = 9.0' (SfA0.5) (cultivated straight rows surface)
V = 7.0' (SfA0.5) (short grass pasture surface)
V = 5.0' (SfA0.5) (woodland surface)
V = 2.5 ' (SfA0.5) (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' (RA(2/3))(SfA0.5)) / 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 (ft2)
Wp = Wetted Perimeter (ft)
V = Velocity (ft/sec)
Sf = Slope (ft/ft)
n = Manning's roughness
User -Defined TOC override (minutes): 32
Subbasin Runoff Results
Total Rainfall (in)............................................................ 6.90
Total Runoff (in)............................................................. 3.85
Peak Runoff (cfs)........................................................... 93.34
Weighted Curve Number ............................................... 73.00
Time of Concentration (days hh:mm:ss) ........................ 0003200

Post -Development 050 - Year Page 6
Subbasin : Sub-47
6
5.8
5.6
5.4
5.2
5
4.8
4.6
4.4
4.2
4
3.8
3.6
3.4
3.2
3
2.8
nm 2.6
2.4
2.2
2
1.8
1.6
1.4
1.2
1
0.8
0.6
0.4
0.2
100
95
90
85
80
75
70
65
60
55
50
0
45
O✓
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 6 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23
Time (hrs)

Post -Development 050 - Year
Subbasin : Sub-48
Page 7
Input Data
Area(ac)........................................................................ 19.86
Peak Rate Factor........................................................... 0.00
Weighted Curve Number ............................................... 86.19
RainGage ID.................................................................
Composite Curve Number
Area
Soil
Curve
Soil/Surface Description
(acres)
Group
Number
> 75 % grass cover, Good
6.34
B
61.00
Paved parking & roofs
8.38
A
98.00
Paved parking & roofs
2.09
A
98.00
Paved roads with curbs & sewers
0.71
C
98.00
Paved roads with curbs & sewers
2.06
C
98.00
Paved roads with curbs & sewers
0.28
C
98.00
Composite Area & Weighted CN
19.86
86.19
Time of Concentration
User -Defined TOC override (minutes): 5
Subbasin Runoff Results
Total Rainfall (in)............................................................ 6.90
Total Runoff (in)............................................................. 5.29
Peak Runoff (cfs)........................................................... 103.58
Weighted Curve Number ............................................... 86.19
Time of Concentration (days hh:mm:ss) ........................ 0000500

Post -Development 050 - Year Page 8
Subbasin : Sub-48
6.2
6
5.8
5.6
5.4
5.2
5
4.8
4.6
4.4
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
110
105
100
95
90
85
80
75
70
65
� 60
0
55
50
o✓
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
11 1 2 3 4 5 6 J 8 9 1U 11 12 13 14 15 18 I 18 19 2U 21 22 23
Time (hrs)

Post -Development 050 - Year Page 9
Pipe Input
SN Element Length Inlet Inlet Outlet Outlet Total Average Pipe
ID Invert Invert Invert Invert Drop Slope Shape
Pipe Pipe Manning's Entrance Exit/Bend Additional Initial Flap No. of
Diameter or Width Roughness Losses Losses Losses Flow Gate Barrels
Elevation Offset Elevation Offset Height
(ft) (ft) (ft) (ft) (ft) (ft) N (in) (in) (cfs)
1 Outlet -Pipe 95.00 568.00 8.00 567.00 -1.00 1.00 1.0500 CIRCULAR 36.000 36.000 0.0150 0.5000 0.5000 0.0000 0.00 No 1

Post -Development 050 - Year Page 10
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 Outlet -Pipe 35.86 0 12:18 1.88 19.12 5.75 0.28 2.46 0.82 0.00 > CAPACITY

Post -Development 050 - Year Page 11
Storage Nodes
Storage Node : Pond-04
Input Data
Invert Elevation (ft)....................................................................
564.50
Max (Rim) Elevation (ft)............................................................
573.50
Max (Rim) Offset (ft)..................................................................
9.00
Initial Water Elevation (ft)..........................................................
568.00
Initial Water Depth (ft)...............................................................
3.50
Ponded Area (ft2).......................................................................
1.00
Evaporation Loss.......................................................................
0.00
Outflow Weirs
Outflow Orifices
SN Element
Weir Flap
Crest
Crest
Length
Weir Total Discharge
ID
Type Gate
Elevation
Offset
Height Coefficient
(ft)
(ft)
(ft)
(ft)
1 Spillway-04
Trapezoidal No
572.75
8.25
20.00
1.00 3.33
2 Weir-04
Rectangular No
570.00
5.50
2.00
3.00 3.33
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 CS -RIM Bottom
Rectangular
No
60.00
60.00
573.00 0.63
2 WQ-Orifice-04 Side
CIRCULAR
No
3.00
568.00 0.61
Output Summary Results
Peak Inflow (cfs)........................................................................
102.77
Peak Lateral Inflow (cfs)............................................................
102.77
Peak Outflow (cfs).....................................................................
61.05
Peak Exfiltration Flow Rate (cfm)..............................................
0.00
Max HGL Elevation Attained (ft)................................................
573.27
Max HGL Depth Attained (ft).....................................................
8.77
Average HGL Elevation Attained (ft).........................................
570.11
Average HGL Depth Attained (ft)..............................................
5.61
Time of Max HGL Occurrence (days hh:mm) ............................
0 12:17
Total Exfiltration Volume (1000-ft')...........................................
0.000
Total Flooded Volume (ac-in)....................................................
0
Total Time Flooded (min)..........................................................
0
Total Retention Time (sec) ........................................................
0.00

25-YR
CAPACITY

H EC-22
Energy Grade Line Computations
Struct.
Q
EGLo
HGLo
Total Pipe
EGLi
HGLi
Ea
EGLa
Surface Elev.
ID
(cfs)
(ft)
(ft)
Loss
(ft)
(ft)
(ft)
(ft)
(ft)
(ft)
1 (41) 1 576.78
576.78
581.17
583.01
1
579.37
1 (39)
5.81
579.32
578.77
580.62
2.1
581.75
586.56
1 (38)
2.81
581.78
581.70
582.54
1.0
583.01
593.64
3
570.22
570.22
568.66
1
48.3
570.45
570.22
0.14
570.59
570.36
5.9
570.72
584.43
12
37.9
570.81
570.57
0.21
571.02
570.781
5.3
571.141
584.99
13
32.7
571.21
571.03
0.03
571.24
571.06
5.4
571.40
585.35
1 (15)
7.0
574.59
574.09
0.35
574.95
574.44
2.0
575.23
578.65
1 (13)
3.11
575.27
575.17
0.36
575.63
575.54
1.7
575.72
579.80
14
25.91
571.48
571.27
0.19
571.67
571.46
5.1
571.74
582.76
31
1.1
571.74
571.73
0.01
571.75
571.74
5.0
571.77
582.76
14
20.1
571.79
571.66
0.13
571.92
571.791
4.6
571.95
579.82
15
18.8
572.04
571.81
0.44
572.47
572.25
4.4
572.61
576.04
18
7.2
572.64
572.56
0.16
572.81
572.72
3.6
572.83
580.44
19
7.1
575.10
574.46
575.37
574.74
2.0
575.86
582.00
19
6.5
575.95
575.74
0.18
576.12
575.91
2.0
576.26
581.65
21
5.3
576.38
576.08
0.81
577.19
576.90
1.9
577.421
580.25
22
3.6
577.48
577.34
0.11
577.59
577.451
1.8
577.67
580.30
38
7.0
572.71
572.47
0.67
573.37
573.13
3.5
573.49
574.73
38
1.3
573.49
573.48
0.02
573.51
573.50
2.8
573.52
577.96
17
3.6
572.67
572.53
0.09
572.76
572.62
3.9
572.85
576.04
35
1.21
574.95
574.80
0.14
575.09
574.94
0.7
575.23
579.82
34
5.0
571.79
571.66
0.06
571.85
571.73
5.0
571.921
581.11
32
4.9
572.02
571.77
0.57
572.59
572.351
4.9
572.85
579.16
32
2.5
572.87
572.81
0.04
572.91
572.85
4.8
572.99
579.16
27
4.1
578.64
578.35
579.44
579.15
1.0
579.44
587.95
28
4.0
579.50
579.34
579.84
579.55
1.2
580.01
587.09
29
3.91
580.05
579.95
0.50
580.55
580.27
1.5
580.79
585.98
30
1.4
580.80
580.78
0.01
580.81
580.80
1.41
580.83
585.98
2
10.3
570.72
570.71
0.01
570.74
570.72
5.1
570.74
581.91
3
9.7
570.75
570.72
0.03
570.78
570.75
4.0
570.79
578.90
4
8.8
570.80
570.78
0.03
570.83
570.80
3.0
570.84
575.81
6
6.0
570.85
570.83
0.03
570.88
570.86
1.9
570.89
576.78
7
5.3
570.90
570.87
571.03
570.62
1.1
571.03
577.39
8
4.8
571.64
571.23
572.26
571.85
1.1
572.26
579.07
9
4.1
572.29
572.21
573.39
573.02
1.0
573.39
579.77
10
3.3
573.44
573.33
574.12
573.77
1.1
574.20
578.82
11
1.1
574.20
574.19
575.04
574.85
0.5
575.04
580.88
39
574.38
574.38
1
1 571.30
124
23.5
574.47
574.38
0.09
574.57
574.47
6.3
574.64
582.99
125
16.6
574.65
574.61
0.01
574.66
574.62
6.0
574.67
582.93
130
14.9
574.70
574.63
0.04
574.74
574.67
4.9
574.78
579.55
43
10.4
574.79
574.76
0.02
574.81
574.78
3.7
574.84
580.79
44
6.4
574.85
574.82
0.04
574.89
574.86
1.4
575.33
582.60
143
3.21
575.81
575.43
577.63
577.251
0.9
577.631
584.50
50
2.1
576.59
576.42
0.66
577.25
577.09
1.0
577.46
585.17
49
5.9
575.24
574.92
575.92
575.60
1.0
575.92
584.36
47
2.3
575.93
575.91
576.55
576.36
0.7
576.55
586.43
147
0.9
576.56
576.55
0.12
576.68
576.58
0.8
576.77
586.45
153
1.8
576.64
576.46
0.17
576.80
576.62
1.0
577.06
584.64
159
11.91
574.39
574.38
574.40
574.381
7.0
574.401
580.64
52
9.2
574.41
574.40
574.41
574.40
5.4
574.41
581.37
53
5.9
574.42
574.41
0.01
574.43
574.42
3.0
574.44
584.83
165
3.4
574.44
574.43
574.44
574.44
1.1
574.44
591.33
55
0.5
574.44
574.44
575.41
575.25
0.3
575.41
597.27
56
0.2
575.41
575.41
576.39
576.29
0.2
576.39
599.58
177
1 0.11
576.39
576.39
576.8
.801
0.2
576.871
599.58
107
1 2.01
584.37
584.19
0.161
584.53
584.351
1.01
584.771
591.33
iq THOMAS s HUTTON
Z:127842127842.00031 Engineering I Calculations and Reportsl Storm Waterl HEC-22127842.0003 - HEC-22 Reporting.xlsm

H EC-22
Energy Grade Line Computations
Struct.
ID
Q
(cfs)
EGLo
(ft)
HGLo
(ft)
Total Pipe
Loss
(ft)
EGU
(ft)
HGU
(ft)
Ea
(ft)
EGLa
(ft)
Surface Elev.
(ft)
105 1.5 576.541 576.38
0.16
576.70
576.54
0.9
576.941
584.84
103
2.0
575.34
575.16
0.16
575.50
575.32
1.0
575.71
581.38
159
1.0
574.57
574.44
0.16
574.73
574.60
0.7
574.88
580.64
109
573.04
573.04
569.23
112
67.6
573.32
573.041
0.11
573.43
573.151
8.4
573.66
589.42
114
1 67.41
573.77
573.49
0.18
573.96
573.68
8.2
574.20
588.84
134
1.6
581.03
580.55
584.83
584.35
0.8
584.83
587.04
115
66.4
574.37
573.94
0.32
574.69
574.26
8.3
575.05
589.64
137
1.1
579.61
579.21
582.21
581.81
0.7
582.21
590.83
138
0.5
582.21
582.20
582.67
582.44
0.4
582.67
590.84
115
64.6
575.22
574.81
0.21
575.43
575.02
8.4
575.67
588.64
118
31.81
575.71
575.61
0.11
575.82
575.72
7.4
575.86
586.44
119
27.0
575.90
575.78
0.08
575.99
575.87
7.0
576.03
585.34
121
21.3
576.06
575.99
0.04
576.11
576.03
6.6
576.14
584.46
69
15.3
576.20
576.05
0.16
576.36
576.21
6.0
576.44
583.34
126
10.3
576.46
576.40
0.11
576.58
576.51
4.9
576.61
581.75
127
8.8
576.65
576.53
0.22
576.88
576.76
4.1
576.97
580.64
128
0.71
576.97
576.97
576.97
576.97
2.5
576.97
582.38
133
0.2
576.97
576.97
576.97
576.97
2.3
576.97
582.38
186
4.9
577.39
577.11
0.18
577.57
577.29
1.6
577.78
580.64
182
4.0
576.45
576.42
0.01
576.46
576.43
4.7
576.47
583.34
1 (237)
3.7
576.47
576.45
0.04
576.52
576.49
3.4
576.53
583.08
1 (237)
0.6
576.53
576.53
576.53
576.531
2.8
576.53
581.12
1 (237)
2.51
576.53
576.52
0.02
576.55
576.54
2.3
576.56
579.83
105
1.01
576.56
576.56
576.56
576.56
1.8
576.56
581.39
108
6.6
576.15
576.12
0.041
576.19
576.16
5.9
576.21
583.93
109
6.7
576.22
576.19
0.03
576.26
576.23
5.4
576.27
582.31
110
6.0
576.29
576.23
0.16
576.45
576.40
4.4
576.48
579.98
111
4.5
576.49
576.46
0.09
576.58
576.55
3.4
576.59
577.72
112
2.5
576.60
576.57
0.07
576.67
576.64
2.9
576.69
579.77
113
1 1.61
576.70
576.67
0.13
576.82
576.80
2.0
576.85
581.81
176
6.0
576.06
576.00
0.03
576.08
576.02
6.7
576.12
585.34
174
5.4
576.18
576.03
0.09
576.27
576.13
6.6
576.37
584.42
174
5.2
576.42
576.28
0.22
576.64
576.51
6.0
576.71
583.34
178
1.1
576.71
576.70
0.01
576.72
576.71
1.3
576.74
583.33
100
3.4
576.76
576.64
0.56
577.32
577.20
4.8
577.43
580.93
100
1.61
577.44
577.41
0.02
577.46
577.44
4.4
577.48
581.29
171
4.3
575.93
575.74
0.16
576.09
575.90
1.6
576.19
586.43
172
3.6
576.24
576.11
578.95
578.34
1.2
578.95
581.32
144
34.4
575.99
575.19
577.04
575.63
3.1
577.23
588.64
144
32.2
577.36
577.04
0.06
577.42
577.101
3.2
577.59
588.48
142
31.8
577.72
577.41
0.06
577.78
577.47
3.4
578.05
588.48
140
30.51
578.29
577.69
0.98
579.27
578.67
3.9
580.36
590.65
146
14.5
580.41
580.28
0.20
580.61
580.48
2.7
580.73
588.50
82
13.3
580.77
580.66
0.03
580.80
580.69
2.4
580.86
588.50
84
13.2
580.97
580.70
0.09
581.07
580.79
2.4
581.23
589.05
155
11.8
581.32
581.10
0.08
581.40
581.18
2.4
581.59
589.05
156
10.6
581.66
581.48
0.21
581.87
581.69
1.9
582.05
590.15
87
9.81
582.25
581.77
0.79
583.03
582.56
2.3
583.37
591.12
88
6.3
583.45
583.25
584.50
583.90
1.7
584.74
593.38
160
3.6
584.77
584.71
585.62
585.17
1.1
585.62
595.10
163
0.8
585.62
585.62
586.58
586.37
0.5
586.58
596.81
91
0.4
586.58
586.57
586.69
586.56
0.4
586.69
596.79
168
1.4
585.63
585.61
585.63
585.36
0.8
585.63
595.07
167
1.41
586.39
586.22
0.14
586.53
586.36
0.9
586.74
593.36
92
1.9
583.38
583.35
0.02
583.41
583.37
2.1
583.46
591.12
16.6
580.53
580.10
0.21
580.74
580.31
3.8
580.98
590.4
E(2
16.4
581.15
580.72
0.41
581.56
581.14
3.1
581.77
588.31
11.8
581.86
581.63
584.55
583.24
2.2
584.551
590.26
F4 THOMAS s HUTTON
Z:127842127842.00031 Engineering I Calculations and Reportsl Storm Waterl HEC-22127842.0003 - HEC-22 Reporting.xlsm

H EC-22
Energy Grade Line Computations
Struct.
ID
Q
(cfs)
EGLo
(ft)
HGLo
(ft)
Total Pipe
Loss
(ft)
EGU
(ft)
HGU
(ft)
Ea
(ft)
EGLa
(ft)
Surface Elev.
(ft)
1 (248) 9.0 584.61
584.481
1 587.191
586.061
1.91
587.191
591.96
1 (247)
1 6.11
587.26
587.081
1 589.771
588.821
1.61
589.771
593.68
1 (245)
1 3.21
589.81
589.701
1 592.161
591.471
1.21
592.161
595.39
F4 THOMAS s HUTTON
Z:127842127842.00031 Engineering I Calculations and Reportsl Storm Waterl HEC-22127842.0003 - HEC-22 Reporting.xlsm

H EC-22
Storm Drain Computations
Structure ID
Length
(ft)
Drainage
Area
(ac)
Runoff
Coeff "C"
I
Tc
(min)
Rain "I"
(in/hr)
Runoff
"Q"
(cfs)
Known Q
(cfs)
I
Total Q
(cfs)
I
Pipe Dia.
(in)
I
Velocity
Design
I (ft/s)
Invert Elevation
Slope
From To
U/S I D/S
1 (39) 1 (41)
186 0.67 0.551
6
8.13 5.8 5.8 15 6.0 579.70 577.85 1.00%
8.25 2.8 2.8 15 5.5 582.00 579.70 1.25%
7.331 48.3 48.3 481 8.0 564.85 564.24 0.50%
1 (38)
1 (39)
184
0.61
0.55
5
1
3
122
0.44
0.55
9
12
1
146
0.32
0.55
8
7.67
37.9
37.9
42
7.5
565.87
565.14
0.50%
13
12
33
0.09
0.55
8
7.69
32.7
32.7
42
7.2
566.04
565.87
0.50%
1 (15)
113
1 68
0.88
0.551
6
8.10
7.0
7.0
15
5.7
573.19
572.84
0.52%
1 (13)
1 (15)
161
0.67
0.55
5
8.25
3.1
3.1
15
4.0
574.00
573.19
0.50%
14
13
127
0.07
0.55
7
7.76
25.9
25.9
36
6.8
566.67
566.04
0.50%
31
14
24
0.24
0.55
51
8.25
1.1
1.11
15
3.1
566.79
566.67
0.50%
15
14
145
0.10
0.55
7
7.84
20.1
20.1
36
6.4
567.40
566.67
0.50%
17
15
207
0.30
0.55
6
7.98
18.8
18.8
30
5.8
568.24
567.40
0.41%
18
17
158
0.03
0.55
6
8.11
7.2
7.2
24
4.9
569.221
568.44
0.50%
19
18
28
0.14
0.55
6
8.12
7.1
7.1
18
6.4
573.84
573.56
1.00%
20
19
46
0.27
0.55
5
8.15
6.5
6.5
181
6.3
574.30
573.84
1.00%
21
20
120
0.37
0.55
51
8.23
5.3
1 5.3
15
5.9
575.50
574.30
1.00%
22
21
35
0.79
0.55
5
8.25
3.6
3.6
15
5.4
575.85
575.50
1.00%
38
17
152
1.27
0.55
6
8.07
7.0
7.0
18
6.4
569.96
568.44
1.00%
37
38
155
0.28
0.55
5
8.25
1.3
1.3
18
3.2
570.73
569.96
0.50%
36
17
28
0.80
0.55
5
8.25
3.6
3.6
15
4.3
568.96
568.81
0.55%
35
15
28
0.26
0.55
5
8.25
1.2
1.2
151
3.1
574.50
574.36
0.50%
34
14
29
0.03
0.55
5
8.17
5.0
5.0
18
5.9
566.961
566.67
1.00%
32
34
101
0.53
0.55
5
8.23
4.9
4.9
15
5.8
567.96
566.96
1.00%
33
32
28
0.54
0.55
5
8.25
2.5
2.5
15
4.9
568.24
567.96
1.00%
27
12
160
0.04
0.55
6
8.08
4.1
4.1
24
4.3
578.46
577.66
0.50%
28
27
62
0.03
0.55
6
8.13
4.0
4.0
18
4.3
578.77
578.46
0.50%
29
28
1 100
0.55
0.55
5
8.22
3.9
3.9
18
4.2
579.27
578.77
0.50%
30
29
28
0.30
0.55
5
8.25
1.41
1.4
15
3.1
579.391
579.27
0.43%
2
1
111
0.19
0.55
9
7.40
10.3
10.3
42
6.1
565.68
564.86
0.74%
3
2
148
0.25
0.55
8
7.49
9.7
9.7
36
6.1
566.79
565.68
0.74%
4
3
147
0.67
0.55
8
7.59
8.8
8.8
36
5.9
567.88
566.79
0.74%
6
4
149
0.18
0.55
7
7.69
6.0
6.0
30
5.4
568.99
567.88
0.74%
7
6
1 131
0.13
0.55
7
7.79
5.3
1 5.3
301
5.2
569.97
568.99
0.74%
8
7
83
0.17
0.55
7
7.85
4.8
4.8
24
5.1
571.18
570.56
0.74%
9
8
164
0.18
0.55
6
7.98
4.1
4.1
24
4.9
572.40
571.18
0.74%
10
9
100
0.51
0.55
6
8.06
3.3
3.3
18
4.7
573.14
572.40
0.74%
11
10
182
0.24
0.55
5
8.25
1.1
1.1
18
3.5
574.50
573.14
0.74%
124
39
1 173
0.27
0.55
7
7.89
23.5
1 23.5
421
8.5
568.37
566.64
1.00%
125
124
29
0.38
0.55
7
7.91
16.6
16.6
42
7.7
568.66
568.37
1.00%
130
125
78
0.60
0.55
6
7.94
14.9
14.9
36
8.9
569.88
568.66
1.56%
43
130
102
0.92
0.55
6
8.00
10.4
10.4
36
6.1
571.12
570.38
0.73%
44
43
184
0.72
0.55
6
8.12
6.4
6.4
30
6.1
573.96
572.12
1.00%
143
44
182
0.69
0.55
51
8.25
3.2
3.2
30
5.0
576.77
574.96
1.00%
50
130
176
0.46
0.55
5
8.25
2.1
2.1
18
3.3
576.50
575.84
0.38%
49
124
136
0.41
0.55
6
8.00
5.9
5.9
36
4.5
574.89
574.21
0.50%
47
49
198
0.32
0.55
5
8.21
2.3
2.3
30
3.5
575.88
574.89
0.50%
147
47
28
0.19
0.55
5
8.25
0.9
0.9
30
2.5
576.00
575.88
0.43%
153
49
36
0.40
0.55
5
8.25
1.8
1.8
15
3.4
576.06
575.89
0.46%
159
39
48
0.42
0.55
71
7.72
11.9
11.9
48
8.0
567.371
566.64
1.50%
52
159
107
0.34
0.55
7
7.78
9.2
1 9.2
481
7.4
568.98
567.37
1.50%
53
52
163
0.26
0.55
7
7.87
5.9
5.9
36
6.7
571.43
568.98
1.50%
165
53
130
0.22
0.55
6
7.96
3.4
3.4
36
5.7
573.37
571.43
1.50%
55
165
113
0.06
0.55
6
8.08
0.5
0.5
30
3.3
575.07
573.37
1.50%
56
55
73
0.03
0.55
5
8.19
0.2
0.2
30
2.6
576.17
575.07
1.50%
177
56
36
0.03
0.55
51
8.25
0.1
0.1
24
2.2
576.71
576.17
1.50%
107
165
361
0.441
0.55
5
8.25
2.01
1 2.0
15
3.4
583.75
583.59
0.44%
105
53
36
0.33
0.55
5
8.25
1.51
1 1.5
15
3.2
576.03
575.87
0.44%
103
52
36
0.43
0.55
5
8.25
2.0
2.0
15
3.4
574.73
574.57
0.44%
101
159
36
0.231
0.55
5
8.25
1.01
1 1.0
15
2.9
574.181
574.02
0.44%
Pi THOMAS & HUTTON
Z:127842127842.00031 Engineering I Calculations and Reportsl Storm Waterl HEC-22127842.0003 - HEC-22 Reporting.xlsm

H EC-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
112
109
89
0.24
0.55
11
6.89
67.6
67.6
54
8.7
565.25
564.81
0.50%
114
112
156
0.08
0.55
11
6.95
67.4
67.4
54
8.7
566.03
565.25
0.50%
134
114
190
0.34
0.55
5
8.25
1.6
1.6
15
5.6
584.00
580.20
2.00%
115
114
150
0.30
0.55
10
7.02
66.4
66.4
48
8.6
566.78
566.03
0.50%
137
1115
1 130
0.15
0.55
5
8.221
1.1
1.1
15
5.1
581.51
578.92
2.00%
138
137
36
0.10
0.55
5
8.25
0.5
0.51
15
3.9
582.25
581.51
2.03%
118
115
106
0.26
0.55
10
7.07
64.6
64.6
48
8.6
567.31
566.78
0.50%
119
118
234
0.32
0.55
10
7.19
31.8
31.8
48
7.2
568.48
567.31
0.50%
121
119
116
0.10
0.55
9
7.25
27.0
27.0
42
6.9
569.06
568.48
0.50%
69
121
94
0.08
0.55
9
7.31
21.3
21.3
42
6.5
569.53
569.06
0.50%
126
69
119
0.27
0.55
7
7.72
15.3
15.3
30
7.0
570.42
569.53
0.75%
127
126
175
0.38
0.55
7
7.83
10.3
10.3
30
6.3
571.73
570.42
0.75%
128
127
150
0.77
0.55
6
7.92
8.8
8.8
24
6.1
572.86
571.73
0.75%
131
128
213
0.12
0.55
5
8.19
0.7
0.7
24
3.0
574.46
572.86
0.75%
133
131
36
0.04
0.55
5
8.25
0.2
0.2
15
2.1
574.73
574.46
0.75%
186
128
36
1.06
0.55
5
8.25
4.9
4.9
15
4.2
576.17
575.99
0.50%
182
126
1 36
0.091
0.55
7
7.83
4.0
4.0
24
5.2
571.79
571.47
0.87%
1 (237)
182
155
0.13
0.55
6
7.95
3.7
3.7
24
5.1
573.15
571.79
0.87%
104
1 (237)
64
0.14
0.55
5
8.25
0.6
0.6
18
3.1
573.71
573.15
0.87%
105
1 (237)
159
0.35
0.55
6
8.11
2.5
2.5
24
3.7
574.21
573.42
0.50%
106
105
107
0.21
0.55
5
8.25
1.0
1.0
24
2.8
574.75
574.21
0.50%
108
69
149
0.00
0.55
9
7.43
6.6
6.6
30
4.8
570.28
569.53
0.50%
109
108
1 129
0.211
0.55
8
7.53
6.7
1 6.7
30
4.81
570.92
570.28
0.50%
110
109
231
0.37
0.55
7
7.71
6.0
6.0
24
4.7
572.08
570.92
0.50%
111
110
225
0.47
0.55
7
7.91
4.5
4.5
24
4.4
573.20
572.08
0.50%
112
111
122
0.21
0.55
6
8.03
2.5
2.5
18
3.8
573.81
573.20
0.50%
113
112
204
0.35
0.55
5
8.25
1.6
1.6
15
3.4
574.83
573.81
0.50%
176
121
36
0.14
0.55
6
8.00
6.0
6.0
241
6.1
569.44
569.08
1.00%
174
176
36
0.04
0.55
6
8.02
5.4
5.4
18
6.0
569.80
569.44
1.00%
178
174
89
0.18
0.55
61
8.08
5.2
5.2
18
5.9
570.69
569.80
1.00%
102
178
28
0.24
0.55
5
8.25
1.1
1.1
15
3.0
575.49
575.35
0.50%
100
178
198
0.41
0.55
5
8.22
3.4
3.4
15
5.3
572.67
570.69
1.00%
181
100
41
0.34
0.55
5
8.25
1.6
1.6
15
4.3
573.081
572.67
1.00%
171
119
36
0.18
0.55
6
8.13
4.3
4.3
151
6.6
574.63
574.09
1.50%
172
171
208
0.78
0.55
5
8.25
3.6
3.6
15
6.3
577.75
574.63
1.50%
144
118
36
0.54
0.55
81
7.52
34.4
34.4
36
9.5
574.10
573.74
1.00%
142
144
28
0.12
0.55
8
7.53
32.2
32.2
36
9.4
574.38
574.10
1.00%
140
142
28
0.36
0.55
8
7.55
31.8
31.8
36
9.3
574.66
574.38
1.00%
146
140
177
0.06
0.55
8
7.62
30.5
30.5
30
9.2
576.431
574.66
1.00%
150
146
161
0.28
0.55
7
7.70
14.5
14.5
301
7.6
578.04
576.43
1.00%
82
150
28
0.02
0.55
7
7.71
13.3
13.3
30
8.6
578.46
578.04
1.50%
84
82
28
0.33
0.55
71
7.72
13.2
13.2
24
8.7
578.87
578.46
1.50%
155
84
28
0.30
0.55
7
7.74
11.8
11.8
24
7.9
579.22
578.87
1.25%
156
155
95
0.21
0.55
7
7.79
10.6
10.6
24
7.1
580.18
579.22
1.00%
87
156
91
0.42
0.55
7
7.84
9.8
9.8
18
6.8
581.08
580.18
1.00%
88
87
198
0.31
0.55
6
7.96
6.3
6.3
181
6.2
583.07
581.08
1.00%
160
88
1 150
0.31
0.55
6
8.06
3.6
3.6
18
5.4
584.57
583.07
1.00%
163
160
150
0.10
0.55
51
8.22
0.8
0.8
15
3.6
586.07
584.57
1.00%
91
163
28
0.09
0.55
5
8.25
0.4
0.4
15
2.91
586.35
586.07
1.00%
168
160
28
0.31
0.55
5
8.25
1.4
1.4
15
4.2
584.85
584.57
1.00%
167
88
28
0.31
0.55
5
8.25
1.4
1.4
15
3.3
585.88
585.74
0.50%
92
87
28
0.41
0.55
5
8.25
1.9
1.9
15
4.6
581.36
581.08
1.00%
1 (290)
146
1 39
0.05
0.55
6
7.92
16.6
16.6
24
10.0
577.16
576.43
1.88%
1 (266)
1 (290)
79
1.06
0.55
61
7.95
16.4
1 16.4
24
10.0
578.64
577.16
1.88%
1 (252)
1 (266)
199
0.66
0.55
6
8.03
11.8
11.8
24
9.2
582.38
578.64
1.88%
1 (248)
1 (252)
157
0.65
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F4 THOMAS & HUTTON
Z:127842127842.00031 Engineering I Calculations and Reportsl Storm Waterl HEC-22127842.0003 - HEC-22 Reporting.xlsm

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CRESSWIND WESLEY CHAPEL - PHASE 03
APPENDIX F
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— D,th. Node - Pond-04 (27842 0003 --ER QUALITY 2021-04-0211 28.24)
35
Time (hY5)

Cresswind Wesley Chapel - Phase 02 Job: J-27842.0002
T z KH Wesley Chapel, LLC Date: 2/18/21
HP Thomas & Hutton Engineering Co. Revised:
~FEaµ
Anti -Flotation Design Considerations By: MSK
ANTI -FLOTATION DESIGN CONSIDERATIONS FOR:
Wet Pond 02
CONTROL STUCTURE ELEVATIONS
Top Structure Elevation: 570.20
Bottom Structure Elevation: 561.00
CONTROL STRUCTURE FLOTATION
Buoyant Force
Calculate submerged volume:
Vs = (As x H,$)
Where:
VS = Submerged volume (cf)
L,s = Length of control structure (ft) = 6.00 ft
W,s = Width of Control structure (ft) = 6.00 ft
A,s- Cross -sectional area of control structure (ft) = 36.00 ft
H,s = Height of control structure (ft) = 9.20 ft
Solve equation for Vs:
Vs = (A,s x H,$) = 331.20 cf
Calculate buoyant force:
Fb = Vs x 7w.W,
Where:
Fb = buoyant force (lbf)
y,,,, = Specific weight of water = 62.40 lbf/cf
Fb = 20,667 lbf
Z:\27842\27842.0002\Engineering\Calculations and Reports\Storm Water\Anti Flotation\27842.0002 - Wet Pond 03 - Anti Flotation
Design Calculations.xlsx Pagel of 3

Cresswind Wesley Chapel - Phase 02 Job: J-27842.0002
T z KH Wesley Chapel, LLC Date: 2/18/21
HP Thomas & Hutton Engineering Co. Revised:
~FEaµ
Anti -Flotation Design Considerations By: MSK
Downward Force
Calculate Downward Force of Control Structure
Fdcs = (• cs - Vw& - Vorj&c) X Yconcrete
Where:
WteS =
Weight of control structure (lbs)
Yconcrete =
Specific weight of concrete
= 140.00 lbf/cf
Acs =
Cross -sectional area of control structure (ft)
= 36.00 ft
Hcs =
Height of control structure (ft)
= 9.20 ft
Tcs =
Wall thickness of control structure (ft)
= 0.50 It
Vcs =
Volume of control structure (cf)
= 101.20 cf
Wu,eu =
Width of weir (ft)
= 4.00 ft
Hu,eu
= Height of weir opening (ft)
= 3.40 ft
Au,eu
= Area of weir opening(ft)
= 13.60 sf
Vu,e;r
= Volume of weir
= 6.80 cf
DIAorifice
= Diameter of orifice opening (in)
= 5.00 in
Aorifice
= Area of orifice opening (sf)
= 0.136 sf
Vorifice
= Volume of orifice opening (sf)
= 0.068 cf
FdeS = 13,206 lbf
Size Anti -Flotation Footing to Resist Bouyant Force
FdeS + Fdft > Fb
Fdft = (Lb X Wb X Db) X Yconcrete
Where:
FdeS =
downward force of control structure (lbf) =
13206 lbf
Fb =
buoyant force (lbf) =
20667 lbf
Yconcrete =
Specific weight of concrete =
77.60 lbf/cf
Lb
= Length of Concrete Block =
12.00 ft
Wb =
Width of Concrete Block =
12.00 ft
Db
= Depth of Concrete Block =
12.00 in
Fdft =
downward force of anti -flotation footing (lbf) =
11174 lbf
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Design Calculations.xlsx Page 2 of 3

Cresswind Wesley Chapel - Phase 02
KH Wesley Chapel, LLC
Thomas & Hutton Engineering Co.
Job: J-27842.0002
Date: 2/18/21
Revised:
Anti -Flotation Design Considerations By: MSK
Fd, + Fdtt = 24381 lbf > Fb = 20667 lbf _
Factor of Safety
Confirm anti -flotation block is sized for minimum factor of safety (F,) of 1.10.
Fs = (Fdcs + Fdrt)/Fb
1.18 > 1.10 -
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Design Calculations.xlsx Page 3 of 3