SW3210301_Design Calculations (Stormwater - Phase 2)_20210602

.1r.
Iq
STORMWATER MANAGEMENT REPORT
FOR:
CRESSWIND WESLEY CHAPEL - PHASE02
I I I I I I I
E S S/O/�..
WESLEY CHAPEL., NC
PREPARED FOR:
KH WESLEY CHAPEL.. LLC
�A C
0�
T H 0 M A S
HUTTON
ENGINEERING
co
N F-0871
R\�
1,, 4
OF
J-#27842.0002
FEBUARARY 16..2021
LATEST REVISION: JUNE 1., 2021
Prepared by:
THOMAS & HUTTON

STORMWATER MANAGEMENT REPORT
Cresswind Wesley Chapel - Phase 02
Project: Cresswind Wesley Chapel - Phase 02
T&H Job Number: J-27842.0002
Location: Potter Road
Wesley Chapel, NC 28173
Date Prepared: February 16, 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]
FJ 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
FJ THOMAS & HUTTON
Page 2

SECTION I - SUMMARY OF RESULTS
Table I - Pre Development Runoff Rates
TABLE I
Summary of Results - Existing Conditions
Storm Event
Ouffaill 01
Ouffaill 02
Combined
(cfs)
(cfs)
(cfs)
2-year
66
14
80
1 0-Year
134
31
16
25-Year
173
41
214
50-Year
208
51
259
Table 2 - Post Development Runoff Rates
TABLE I
Summary of Results - Proposed Conditions
Storm Event
Ouffaill 01
Ouffaill 02
Combined
(cfs)
WS)
WS)
2-year
60
9
69
1 0-Year
129
19
148
25-Year
172
25
197
50-Year
184
31
215
Fj THOMAS & HUTTON
Page 3

SECTION 2 - PROJECT NARRATIVE
Cresswind is a residential subdivision within Wesley Chapel, North Carolina. Phase 2 consists of
approximately 76 single family detached units. 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 preclevelopment runoff rates to the post
development runoff rates as shown in the summary at the beginning of this report. The pre -
development basins SUB-01 and SUB-02 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.
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 for
each phase that is permitted.
FJ 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-clevelopment 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 I -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 85% 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
Fj THOMAS & HUTTON
Page 5

conveyance such as pipes, channels, control structures, weirs, etc. The sizes, inverts, lengths, and
Manning "n" values for all pipes connecting the ponds or lakes are input into the model. In
addition to pipe information, all pond, lake, and detention area stage -area information and the
respective control structure information is input into the model. The node and link conditions are
analyzed within the model for a given storm, and flow conditions are determined.
Hydrographs for each drainage area are merged within the SSA program, and the hydrologic
results are then combined with the hydraulic information to model the hydraulic interactions of
the entire drainage system. The results include pond area and discharge rates and stage/storage
information during the storm events.
The storm drainage infrastructure onsite was modelled using the 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
0 SCS TR-55 Method was used.
The rainfall distribution 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, 24-hour Design Storm =
3.50 inches
- 1 0-year, 24-hour Design Storm =
5.20 inches
- 25-year, 24-hour Design Storm =
6. 10 inches
- 50-year, 24-hour Design Storm =
6.90 inches
- I 00-year, 24-hour Design Storm
7.50 inches
SCS Type 11 Statistical Rainfall Distribution was used. This distribution pattern is determined
by the Soil Conservation Service comparing regional rain -gage data.
0 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 appenclicies 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
Fj THOMAS & HUTTON
Page 6

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)
0.007(nL)')-8
ti � P2 0.05 x S 0.4
Shallow Concentrated Flow: (hr)
L
t2 - -
3600 X V
Channel Flow: (hr)
L
t3 - -
3600 X V
Time of Concentration: (hr)
t, � t1 + t2 + 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
f t/s
*Based on TR-55 velocity -slope relationship
Symbol
Dimension
Units
L
Length of flow
ft
V*
Velocity
f t/s
*Assumed to be 2 ft/s
Appendices C and E with time of concentration information are attached.
Mr.
14 THOMAS & HUTTON
Page 7

SECTION 8 - EXISTING CONDITIONS
The total acreage of the drainage basins analyzed in the stormwater calculations is
approximately 81 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" and Outfall "02" discharge 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 82 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, fifty (50) year and one hundred (100) 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, fifty
(50) and one hundred (100) year storm events.
FJ THOMAS & HUTTON

Table 3 - Wet Detention Pond 03
Bottom of Pond = 559.00
Crest of Emergency Spillway = 571.00
Top of Embankment = 571.50
Wet Detention Pond 03
Storm Event
Max Elevation
(ft)
1 0-Year
568.94
25-Year
569.31
50-Year
569.75
1 00-Year
570.13
Fj THOMAS & HUTTON
Page 9

STORMWATER MANAGEMENT REPORT
CRESSWIND WESLEY CHAPEL - PHASE 02
APPENDix A
PROJECT MAPPING
27842.0002
Fq THOMAS & HUTTON

N
ai
u
N
m
N U
ro
c
u
u
UD
-0
m
r,4 u
ro
ai
-0
E
D
c
ai
E
c
co
<
D
C"
ai
ro 0
u
'j
Q-
< OJ -0
N
<
0
-c'
<
ai
<
El
19
19 El
0
0
0 0
>
ai
M'j
El
LU
Ad <
4P.- .1
- N"N
Lu
pm
7
91

co
N
M
N
C'4 E
U-)
ro
ro 0
< u M
C" 'j
ai Q_
<
1:119 19 El
ai
u
N U
ro
OJ -0
N
_C,
0
0
0 W
ai
>
ai
Mj
E
<
El
am
0
LL.
Lij
LLI
LU

Q
'20 -aC No
10
x
N
c
N
4)
_1
No
x CL
CL
CL
m c
E
E
wo
S
CL c
16
0 c 0
Vo
c
c;
.2
-0 (0
x F= 0
8
(0
4) CL
E 0 0
E '0' '21
E
(0
>
00 00 B-
cc , .0
(NO
0
.0
(0
0 E
2 .0 (0
N .0
LLI
0 0
0
4) 4) —
< No 00 .0�
R '2 E 10
'0
0
'0
4)
o
-Z
.0
'a - %
(0
1=1 z 0
:00
- .0
0
UR
-0 (0
N
'00 0
CO CC) 0
(o o c
N
4) i
.E
E
0 0
2
(0 (00
M(O
(0
(CO 00
E
11
(00
�2 .1.1 -0.
(co
00
E
0
F, 4) 00
(o
=0 2
(N
o
, .0
0 1 2 s
70 .
-7
M
4) >
—
0 4) 0
4)
(>O
4) -p
. -C
'0 0
t: .0 (L E
'0
4) 4) E 'o
4)
Z -0 '0 0 0
0
o 0 z F,
E
. c
4) 0
0 LL, CO
z
c 0
CL
0 2
W, 2
.0 Lu
4) (D 'o -Z
'40) 4)
.
0
0 > 0
E
0
LL,
c
0 0
0 4)
.—
10 z C
o U)
(0 CL
(o
(0
4)
-0 CL
4) m
CO
> 6
.> 0 .0 E >
- 0
8 CL (o (,0,
c (CO 4)
< -
4)
>
0 z
0
75
c
4)
U) U)
o
0 -
CL
0.
(0
4)
>
(0 .-
4i6
.0
I-
0 (0
S
4) (0 '0
E C
z
<
=0
R
CL
(o
0
C
(o
0 M
(o
2
i5
-a 0
E
7a S
0 :t!
0
> 40)
0 C -0
.5 4)
OC
4) 0 2 '0
IN,
C, "0' (o
2
o (0
u co
o
u IL
0 z
c
za
'0
C 75
LL, 0 7EL
E 3:
4) 4)
.0 (00
— .0 4) E
0
CL
0 c
CL (0
E
o
0
3:
Eo -.0 C-1, 'C' C.
4) 0) E 2
(o .0
�L- �3 8
.0 m CL -0
CIL (0 0
0> CL E E
3: -ow
CL 0 —
c - -, — .
; = 0 (0
. (0 -, C
'a (o '- -(oo
E E CL
�z ol - 4)
4)
o za E 0
M
LL
0
< LLI
LLI LLI
-1
0
> 4) z CL
0 M
-0 (o — CL
'0
w
(n <
N
LLI
LLI
LLI
z
0 0 E
CL 2 4)
(0 - .
CCO
'0 0 2 0
o CL 4)
U 0 4) 1
CL c 4)
S
(o (o CL
0
LL
LLI <
z
LLI C.)
E
0 8) 0 E
E - F
—i
m
LLI
LL
CL
:t!
0
0
E E
t"D
C.)
0
(00
715,
LLI N
CL
LLI 0
LL
0
80o4O'4.87"W
CD
CD
CD
cq
Lo
0
Lo
N

o
007zsc ONZzec 000zzsc OD6�ZSC 002�zsc ooz�zsc 009�zsc oc&zsc OOKZSC ooc�zsc
M../VkE .08
0
z
0
2
0
U)
0
2
M..si7.0t, .08
00=2 ONZZsc 000zzsc OD6�ZSC om�zsc ooz.�zsc 0ONZsc OD9�zsc OOKZSC ODUZK
o
Z� 2
M..IVLE .08 0 0
0)
(U
IL
U)
U)
0
U) CL
00
.0
z
Ll
Ln
00
x
>
C/)
Lf)
0.
0 0
>
0
C)
z iiijc
0
z

z
2
0
LL
z
CL
a
z
LU
0
LU
—j
CL
CL
CL
m
E
0
0
An
L
E
0
0
00
(N.
0
0
0) E
C:
6 EL (u
CL
E cu
E
0) 0
U)
(U CL 0 C:
cu = a)
E to
cu
>
c >
cu
-0 0
0
CL
(U 0
cu to E
E cL
C- cu 0 2)
CU E
tc/) (i) E o)
E
'E 2'c -a 2 q)
(1) -� -Fu
c 0 0
LCLJ: - I = 0 (n_
U)
(n
0
'o
CL
OE
U)
a) 2
m
E
U)
U)
0
C/)
06
o E
LO
2 a)
U) C)r
U)
E
m
u) -a o
a) `�
a)
m CM0
U) =; a
a) a)
0
!G
2
3
--)
=a) —
— = — c
0 L -0 "
z
o
m N
CL
cu
(n U)
c IL
101) (1) -0 M
U) -5 m
0
3:
!E 2
E
0
U) 0 W
U)
-r-
-2
-�u
CL
IQ)
U)
0
Z
a)
2
U)
0 —a) < �;,
2 m
o
m 0
0
a)
>�
0
m
a-
0)
0
CL uj M
m E
2
0
>, ol
-�=
0
E
—
S
cL
E m u)
0
a2
o
70 = m
0-
0
U)
(u
-(Qu E
a)
w 0 2 -�5
U) a) -�� CL
�: ,
a)
C)
c2: .2
(UU) -0 a)
0 to
u)
= L 2 )—
a)
2)
'
a)
a)
3:
'T
-i
0 a) Q-'E 0
U) U) U)
—
2
:C:): >
z
U)
=
C: 0
z E
a)
0 0
-0 'E
a)
0) m
�6 wm
E
0 0 (D
In
a) -E
U)
-Fu
.2 -0 C L
-0
0 C
a)
m U)
U)
0
cm -FU
<
�;, (au)
=
0 m
= c Ln E
E
a)
0
E
0 0 (1) (1)
W
<
0
CL 0
CL M
0 4E
U) U)
(1) 0
2
41= .- (.) j�
U)
2 >
a)
a)
m o
E C�
co
0 EL c
a) a)
09 o
a)
(u 2 Ln -2
mn
0
0
LP
0)-
a) E m 15
FL E
cn
CL -0 < m
U) (7)
uo)
N
Oo.E I
to
>
CL
0
.0
0
0 to
0 0
0 m 0-
m 0 FZ
U) 0
0
0 z <
.2
El 0 0 13 LL
0
r_ u
'It
>
0 Z:
0)
0
0
2,
'a)
ao
m
0 0
0 Z
0)
S
16
F
0
0
0
41
.— 0
a.
m 6-0 o z 0) < m ib
S
El El 13 13
0
U)
Z� 2
0 0
0)
m
IL
U)
U)
0
U) CL
0
0
0
0
m
z
>
Cl)
o
. 0
>
0

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
3wl 2
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
a-= 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 02
APPENDIX B
PRE -DEVELOPMENT DRAINAGE MAP
27842.0002
Fq THOMAS & HUTTON

(Alz
P x

STORMWATER MANAGEMENT REPORT
CRESSWIND WESLEY CHAPEL - PHASE 02
APPENDIX C
PRE -DEVELOPMENT CONDITIONS
DRAINAGE CALCULATIONS
27842.0002
Fq THOMAS & HUTTON

277842.0002
CRESSWIND WESLEY CHAPEL - PHASE 02
PRE -DEVELOPMENT BASINS MODEL

Pre -Development 002 - Year Page 1
Project Description
File Name .................................................... 27842.0002 - Pre Development.SPF
Project Options
Flow Units ...................................................
CIFS
Elevation Type ............................................
Elevation
Hydrology Method .......................................
SCS TR-55
Time of Concentration (TOC) Method ........
SCS TR-55
Link Routing Method ...................................
Hydrodynamic
Enable Overflow Poncling at Nodes ............
YES
Skip Steady State Analysis Time Periods
NO
Analysis Options
Start Analysis On ........................................
Dec 03, 2019
000000
End Analysis On ..........................................
Dec 04, 2019
000000
Start Reporting On ......................................
Dec 03, 2019
000000
Antecedent Dry Days ..................................
0
days
Runoff (Dry Weather) Time Step ................
001 0000
days hh:mm:ss
Runoff (Wet Weather) Time Step ...............
0000500
days hh:mm:ss
Reporting Time Step ...................................
0000500
days hh:mm:ss
Routing Time Step ......................................
15
seconds
Number of Elements
Qty
RainGages .................................................
1
Subbasins....................................................
2
Nodes...........................................................
2
Junctions --------------------------------------------
0
Outfalls -----------------------------------------------
2
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
SIN 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 NorthCarolina Union 2 3.50 SCS Type 11 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-01
63.74 484.00 75.96
3.50
1.36
86.88
65.63
0 003613
2 SUB-02
17.12 484.00 71.63
3.50
1.10
18.84
13.90
0 003502

Pre -Development 002 - Year Page 3
Node Summary
SIN Element Element
Invert Ground/Rim
Initial Surcharge Poncled Peak Max HGL
Max
Min Time of
Total Total Time
ID Type
Elevation
(Max)
Water Elevation Area Inflow Elevation Surcharge Freeboard Peak
Flooded Flooded
Elevation Elevation Attained
Depth
Attained Flooding
Volume
Attained
Occurrence
(ft)
(ft)
(ft) (ft) (ft') (cfs) (ft)
(ft)
(ft) (days hh:mm)
(ac-in) (min)
1 Out-01 Outfall
540.00
0.00 0.00
2 Out-02 Outfall
556.00
0.00 0.00

Pre -Development 002 - Year
Subbasin Hydrology
Page 4
Subbasin : SUB-01
Input Data
Area(ac) ........................................................................
63.74
Peak Rate Factor ...........................................................
484.00
Weighted Curve Number ...............................................
75.96
Rain Gage I D .................................................................
Rain Gage-001
Composite Curve Number
Area
Soil
Curve
Soii/Surface Description
(acres)
Group
Number
Woods, Fair
14.32
D
79.00
Woods, Fair
10.68
D
79.00
Pasture, grassland, or range, Good
38.74
C
74.00
Composite Area & Weighted CN
63.74
75.96
Time of Concentration
TOC Method SCSTR-55
Sheet Flow Equation :
Tc = (0.007 * ((n * Lf)^0.8)) / ((PAO.5) * (SfAO.4))
Where
Tc =
Time of Concentration (hr)
n =
Manning's roughness
Lf =Flow
Length (ft)
P =
2 yr, 24 hr Rainfall (inches)
Sf =Slope
(fVft)
Shallow Concentrated Flow Equation
V =
16.1345 (SfAO.5) (unpaved surface)
V =
20.3282 (SfAO.5) (paved surface)
V =
15.0 (SfAO.5) (grassed waterway surface)
V =
10.0 (SfAO.5) (nearly bare & untilled surface)
V =
9 0 (SfAO.5) (cultivated straight rows surface)
V =
7.0 (SfAO.5) (short grass pasture surface)
V =
5.0 (SfAO.5) (woodland surface)
V =
2.5 (SfAO.5) (forest w/heavy litter surface)
Tc
= (U V) / (3600 sec/hr)
Where
Tc Time of Concentration (hr)
Lf Flow Length (ft)
V Velocity (fVsec)
Sf Slope (fVft)
Channel Flow Equation:
* = (1.49 - (RA(2/3)) * (SfAO.5)) / n
* =Aq/Wp
Tc = (U / 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 (fVsec)
Sf =
Slope (ft/ft)
n =
Manning's roughness

Pre -Development
Sheet Flow Computations
Manning's Roughness:
Flow Length (ft):
Slope (%):
2 yr, 24 hr Rainfall (in)
Velocity (ft/sec) :
Computed Flow Time (min):
Shallow Concentrated Flow Computations
Flow Length (ft):
Slope (%):
Surface Type
Velocity (ft/sec)
Computed Flow Time (min):
Total TOC (min) .................. 36.23
Subbasin Runoff Results
002 - Year Page 5
Flowpath Flowpath Flowpath
A B C
0.4 0.00 0.00
100 0.00 0.00
1 0.00 0.00
3.50 0.00 0.00
0.06 0.00 0.00
27.09 0.00 0.00
Flowpath Flowpath Flowpath
A B C
1771 0.00 0.00
4 0.00 0.00
Unpaved Unpaved Unpaved
3.23 0.00 0.00
9.14 0.00 0.00
Total Rainfall (in) ............................................................
3.50
Total Runoff (in) .............................................................
1.36
Peak Runoff (cfs) ...........................................................
65.63
Weighted Curve Number ...............................................
75.96
Time of Concentration (days hh:mm:ss) ........................
0003614

Pre -Development 002 - Year Page 6
Subbasin : SUB-01
5
4.8
4.6
44
4.2
4
3.8
3.6
3.4
3.2
3
2.8
2.b
2.4
m 22
ry
2
1.8
1.6
1.4
1.2
1
0.8
0.6
04
0.2
75
70
BF,
60
55
50
45
40
35
ry
30
25
20
15
10
F,
Rainfall Intensity Graph
0 1 2 3 4 F, 6 7 a 9 in 11 12 13 14 1 F, 16 17 18 19 20 21 22 23
Time (hrs)
Runoff Hydrograph
01234567891011121314151617181920212223
Time (hrs)

Pre -Development 002 - Year
Subbasin : SUB-02
Page 7
Input Data
Area(ac) ........................................................................ 17.12
Peak Rate Factor ........................................................... 484.00
Weighted Curve Number ............................................... 71.63
Rain Gage I D ................................................................. Rain Gage-001
Composite Curve Number
Area
Soil Curve
Soil/Surface Description
(acres)
Group Number
Pasture, grassland, or range, Good
14.00
C 74.00
Pasture, grassland, or range, Good
3.12
B 61.00
Composite Area & Weighted CN
17.12
71.63
Time of Concentration
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 (%):
1.11
0.00 0.00
2 yr, 24 hr Rainfall (in)
3.50
0.00 0.00
Velocity (fUsec) :
0.06
0.00 0.00
Computed Flow Time (min):
25.99
0.00 0.00
Flowpath
Flowpath Flowpath
Shallow Concentrated Flow Computations
A
B C
Flow Length (ft):
1531.55
0.00 0.00
Slope (%):
3.06
0.00 0.00
Surface Type
Unpaved
Unpaved Unpaved
Velocity (fUsec)
2.82
0.00 0.00
Computed Flow Time (min):
9.05
0.00 0.00
Total TOC (min) .................. 35.04
Subbasin Runoff Results
Total Rainfall (in) ............................................................
3.50
Total Runoff (in) .............................................................
1.10
Peak Runoff (cfs) ...........................................................
13.90
Weighted Curve Number ...............................................
71.63
Time of Concentration (days hh:mm:ss) ........................
0003502

Pre -Development 002 - Year Page 8
Subbasin : SUB-02
5
4.8
4.6
44
4.2
4
3.8
3.6
3.4
3.2
3
2.8
2.b
2.4
m 22
ry
2
1.8
1.6
1.4
1.2
1
0.8
0.6
04
0.2
14.5
14
13.5
13
12.5
12
11.5
11
in JI
10
9.5
9
8.5
8
7.5
7
6.5
ry
5.5
5
4.5
4
3.5
3
2.5
2
1 JI
0.5
Rainfall Intensity Graph
0 1 2 3 4 F, 6 7 a 9 in 11 12 13 14 1 F, 16 17 18 19 20 21 22 23
Time (hrs)
Runoff Hydrograph
01234567891011121314151617181920212223
Time (hrs)

Pre -Development 010 - Year Page 1
Project Description
File Name .................................................... 27842.0002 - Pre Development.SPF
Project Options
Flow Units ...................................................
CIFS
Elevation Type ............................................
Elevation
Hydrology Method .......................................
SCS TR-55
Time of Concentration (TOC) Method ........
SCS TR-55
Link Routing Method ...................................
Hydrodynamic
Enable Overflow Poncling at Nodes ............
YES
Skip Steady State Analysis Time Periods
NO
Analysis Options
Start Analysis On ........................................
Dec 03, 2019
000000
End Analysis On ..........................................
Dec 04, 2019
000000
Start Reporting On ......................................
Dec 03, 2019
000000
Antecedent Dry Days ..................................
0
days
Runoff (Dry Weather) Time Step ................
001 0000
days hh:mm:ss
Runoff (Wet Weather) Time Step ...............
0000500
days hh:mm:ss
Reporting Time Step ...................................
0000500
days hh:mm:ss
Routing Time Step ......................................
15
seconds
Number of Elements
Qty
RainGages .................................................
1
Subbasins....................................................
2
Nodes...........................................................
2
Junctions --------------------------------------------
0
Outfalls -----------------------------------------------
2
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
SIN 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 NorthCarolina Union 10 5.20 SCS Type 11 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-01
63.74 484.00 75.96
5.20
2.70
171.97 134.44
0 003613
2 SUB-02
17.12 484.00 71.63
5.20
2.32
39.76 31.33
0 003502

Pre -Development 010 - Year Page 3
Node Summary
SIN Element Element
Invert Ground/Rim
Initial Surcharge Poncled Peak Max HGL
Max
Min Time of
Total Total Time
ID Type
Elevation
(Max)
Water Elevation Area Inflow Elevation Surcharge Freeboard Peak
Flooded Flooded
Elevation Elevation Attained
Depth
Attained Flooding
Volume
Attained
Occurrence
(ft)
(ft)
(ft) (ft) (ft') (cfs) (ft)
(ft)
(ft) (days hh:mm)
(ac-in) (min)
1 Out-01 Outfall
540.00
0.00 0.00
2 Out-02 Outfall
556.00
0.00 0.00

Pre -Development 010 - Year
Subbasin Hydrology
Page 4
Subbasin : SUB-01
Input Data
Area(ac) ........................................................................
63.74
Peak Rate Factor ...........................................................
484.00
Weighted Curve Number ...............................................
75.96
Rain Gage I D .................................................................
Rain Gage-001
Composite Curve Number
Area
Soil
Curve
Soii/Surface Description
(acres)
Group
Number
Woods, Fair
14.32
D
79.00
Woods, Fair
10.68
D
79.00
Pasture, grassland, or range, Good
38.74
C
74.00
Composite Area & Weighted CN
63.74
75.96
Time of Concentration
TOC Method SCSTR-55
Sheet Flow Equation :
Tc = (0.007 * ((n * Lf)^0.8)) / ((PAO.5) * (SfAO.4))
Where
Tc =
Time of Concentration (hr)
n =
Manning's roughness
Lf =Flow
Length (ft)
P =
2 yr, 24 hr Rainfall (inches)
Sf =Slope
(fVft)
Shallow Concentrated Flow Equation
V =
16.1345 (SfAO.5) (unpaved surface)
V =
20.3282 (SfAO.5) (paved surface)
V =
15.0 (SfAO.5) (grassed waterway surface)
V =
10.0 (SfAO.5) (nearly bare & untilled surface)
V =
9 0 (SfAO.5) (cultivated straight rows surface)
V =
7.0 (SfAO.5) (short grass pasture surface)
V =
5.0 (SfAO.5) (woodland surface)
V =
2.5 (SfAO.5) (forest w/heavy litter surface)
Tc
= (U V) / (3600 sec/hr)
Where
Tc Time of Concentration (hr)
Lf Flow Length (ft)
V Velocity (fVsec)
Sf Slope (fVft)
Channel Flow Equation:
* = (1.49 - (RA(2/3)) * (SfAO.5)) / n
* =Aq/Wp
Tc = (U / 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 (fVsec)
Sf =
Slope (ft/ft)
n =
Manning's roughness

Pre -Development
Sheet Flow Computations
Manning's Roughness:
Flow Length (ft):
Slope (%):
2 yr, 24 hr Rainfall (in)
Velocity (ft/sec) :
Computed Flow Time (min):
Shallow Concentrated Flow Computations
Flow Length (ft):
Slope (%):
Surface Type
Velocity (ft/sec)
Computed Flow Time (min):
Total TOC (min) .................. 36.23
Subbasin Runoff Results
010 - Year Page 5
Flowpath Flowpath Flowpath
A B C
0.4 0.00 0.00
100 0.00 0.00
1 0.00 0.00
3.50 0.00 0.00
0.06 0.00 0.00
27.09 0.00 0.00
Flowpath Flowpath Flowpath
A B C
1771 0.00 0.00
4 0.00 0.00
Unpaved Unpaved Unpaved
3.23 0.00 0.00
9.14 0.00 0.00
Total Rainfall (in) ............................................................
5.20
Total Runoff (in) .............................................................
2.70
Peak Runoff (cfs) ...........................................................
134.44
Weighted Curve Number ...............................................
75.96
Time of Concentration (days hh:mm:ss) ........................
0003614

Pre -Development 010 - Year Page 6
Subbasin : SUB-01
7.5
7
6.5
6
5.5
5
4.5
-E 3.5
3
2.5
2
0.5
140
135
130
125
120
115
110
105
100
95
90
85
00
75
70
65
60
55
50
46
40
35
30
25
20
15
10
5
Rainfall Intensity Graph
0 1 2 3 4 F, 6 7 a 9 in 11 12 13 14 1 F, 16 17 18 19 20 21 22 23
Time (hrs)
Runoff Hydrograph
01234567891011121314151617181920212223
Time (hrs)

Pre -Development 010 - Year
Subbasin : SUB-02
Page 7
Input Data
Area(ac) ........................................................................ 17.12
Peak Rate Factor ........................................................... 484.00
Weighted Curve Number ............................................... 71.63
Rain Gage I D ................................................................. Rain Gage-001
Composite Curve Number
Area
Soil Curve
Soil/Surface Description
(acres)
Group Number
Pasture, grassland, or range, Good
14.00
C 74.00
Pasture, grassland, or range, Good
3.12
B 61.00
Composite Area & Weighted CN
17.12
71.63
Time of Concentration
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 (%):
1.11
0.00 0.00
2 yr, 24 hr Rainfall (in)
3.50
0.00 0.00
Velocity (fUsec) :
0.06
0.00 0.00
Computed Flow Time (min):
25.99
0.00 0.00
Flowpath
Flowpath Flowpath
Shallow Concentrated Flow Computations
A
B C
Flow Length (ft):
1531.55
0.00 0.00
Slope (%):
3.06
0.00 0.00
Surface Type
Unpaved
Unpaved Unpaved
Velocity (fUsec)
2.82
0.00 0.00
Computed Flow Time (min):
9.05
0.00 0.00
Total TOC (min) .................. 35.04
Subbasin Runoff Results
Total Rainfall (in) ............................................................
5.20
Total Runoff (in) .............................................................
2.32
Peak Runoff (cfs) ...........................................................
31.33
Weighted Curve Number ...............................................
71.63
Time of Concentration (days hh:mm:ss) ........................
0003502

Pre -Development 010 - Year Page 8
Subbasin : SUB-02
8
7.5
7
6.5
6
5.5
4.5
4
3.5
ry
3
2.5
2
0.5
34
32
30
28
26
24
22
20
18
16
ry
14
12
in
8
6
4
2
Rainfall Intensity Graph
0 1 2 3 4 F, 6 7 a 9 in 11 12 13 14 1 F, 16 17 18 19 20 21 22 23
Time (hrs)
Runoff Hydrograph
01234567891011121314151617181920212223
Time (hrs)

Pre -Development 025 - Year Page 1
Project Description
File Name .................................................... 27842.0002 - Pre Development.SPF
Project Options
Flow Units ...................................................
CIFS
Elevation Type ............................................
Elevation
Hydrology Method .......................................
SCS TR-55
Time of Concentration (TOC) Method ........
SCS TR-55
Link Routing Method ...................................
Hydrodynamic
Enable Overflow Poncling at Nodes ............
YES
Skip Steady State Analysis Time Periods
NO
Analysis Options
Start Analysis On ........................................
Dec 03, 2019
000000
End Analysis On ..........................................
Dec 04, 2019
000000
Start Reporting On ......................................
Dec 03, 2019
000000
Antecedent Dry Days ..................................
0
days
Runoff (Dry Weather) Time Step ................
001 0000
days hh:mm:ss
Runoff (Wet Weather) Time Step ...............
0000500
days hh:mm:ss
Reporting Time Step ...................................
0000500
days hh:mm:ss
Routing Time Step ......................................
15
seconds
Number of Elements
Qty
RainGages .................................................
1
Subbasins....................................................
2
Nodes...........................................................
2
Junctions --------------------------------------------
0
Outfalls -----------------------------------------------
2
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
SIN 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 NorthCarolina Union 25 6.10 SCS Type 11 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-01
63.74 484.00 75.96
6.10
3.46
220.73 173.39
0 003613
2 SUB-02
17.12 484.00 71.63
6.10
3.04
52.06 41.46
0 003502

Pre -Development 025 - Year Page 3
Node Summary
SIN Element Element
Invert Ground/Rim
Initial Surcharge Poncled Peak Max HGL
Max
Min Time of
Total Total Time
ID Type
Elevation
(Max)
Water Elevation Area Inflow Elevation Surcharge Freeboard Peak
Flooded Flooded
Elevation Elevation Attained
Depth
Attained Flooding
Volume
Attained
Occurrence
(ft)
(ft)
(ft) (ft) (ft') (cfs) (ft)
(ft)
(ft) (days hh:mm)
(ac-in) (min)
1 Out-01 Outfall
540.00
0.00 0.00
2 Out-02 Outfall
556.00
0.00 0.00

Pre -Development 025 - Year
Subbasin Hydrology
Page 4
Subbasin : SUB-01
Input Data
Area(ac) ........................................................................
63.74
Peak Rate Factor ...........................................................
484.00
Weighted Curve Number ...............................................
75.96
Rain Gage I D .................................................................
Rain Gage-001
Composite Curve Number
Area
Soil
Curve
Soii/Surface Description
(acres)
Group
Number
Woods, Fair
14.32
D
79.00
Woods, Fair
10.68
D
79.00
Pasture, grassland, or range, Good
38.74
C
74.00
Composite Area & Weighted CN
63.74
75.96
Time of Concentration
TOC Method SCSTR-55
Sheet Flow Equation :
Tc = (0.007 * ((n * Lf)^0.8)) / ((PAO.5) * (SfAO.4))
Where
Tc =
Time of Concentration (hr)
n =
Manning's roughness
Lf =Flow
Length (ft)
P =
2 yr, 24 hr Rainfall (inches)
Sf =Slope
(fVft)
Shallow Concentrated Flow Equation
V =
16.1345 (SfAO.5) (unpaved surface)
V =
20.3282 (SfAO.5) (paved surface)
V =
15.0 (SfAO.5) (grassed waterway surface)
V =
10.0 (SfAO.5) (nearly bare & untilled surface)
V =
9 0 (SfAO.5) (cultivated straight rows surface)
V =
7.0 (SfAO.5) (short grass pasture surface)
V =
5.0 (SfAO.5) (woodland surface)
V =
2.5 (SfAO.5) (forest w/heavy litter surface)
Tc
= (U V) / (3600 sec/hr)
Where
Tc Time of Concentration (hr)
Lf Flow Length (ft)
V Velocity (fVsec)
Sf Slope (fVft)
Channel Flow Equation:
* = (1.49 - (RA(2/3)) * (SfAO.5)) / n
* =Aq/Wp
Tc = (U / 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 (fVsec)
Sf =
Slope (ft/ft)
n =
Manning's roughness

Pre -Development
Sheet Flow Computations
Manning's Roughness:
Flow Length (ft):
Slope (%):
2 yr, 24 hr Rainfall (in)
Velocity (ft/sec) :
Computed Flow Time (min):
Shallow Concentrated Flow Computations
Flow Length (ft):
Slope (%):
Surface Type
Velocity (ft/sec)
Computed Flow Time (min):
Total TOC (min) .................. 36.23
Subbasin Runoff Results
025 - Year Page 5
Flowpath Flowpath Flowpath
A B C
0.4 0.00 0.00
100 0.00 0.00
1 0.00 0.00
3.50 0.00 0.00
0.06 0.00 0.00
27.09 0.00 0.00
Flowpath Flowpath Flowpath
A B C
1771 0.00 0.00
4 0.00 0.00
Unpaved Unpaved Unpaved
3.23 0.00 0.00
9.14 0.00 0.00
Total Rainfall (in) ............................................................
6.10
Total Runoff (in) .............................................................
3.46
Peak Runoff (cfs) ...........................................................
173.39
Weighted Curve Number ...............................................
75.96
Time of Concentration (days hh:mm:ss) ........................
0003614

Pre -Development 025 - Year Page 6
Subbasin : SUB-01
7.5
7
6.5
6
5.5
5
4.5
-E 4
3.6
3
2.5
2
1 JI
0.5
190
180
170
160
150
140
130
120
110
100
90
80
70
60
60
40
30
20
in
Rainfall Intensity Graph
0 1 2 3 4 F, 6 7 a 9 in 11 12 13 14 1 F, 16 17 18 19 20 21 22 23
Time (hrs)
Runoff Hydrograph
01234567891011121314151617181920212223
Time (hrs)

Pre -Development 025 - Year
Subbasin : SUB-02
Page 7
Input Data
Area(ac) ........................................................................ 17.12
Peak Rate Factor ........................................................... 484.00
Weighted Curve Number ............................................... 71.63
Rain Gage I D ................................................................. Rain Gage-001
Composite Curve Number
Area
Soil Curve
Soil/Surface Description
(acres)
Group Number
Pasture, grassland, or range, Good
14.00
C 74.00
Pasture, grassland, or range, Good
3.12
B 61.00
Composite Area & Weighted CN
17.12
71.63
Time of Concentration
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 (%):
1.11
0.00 0.00
2 yr, 24 hr Rainfall (in)
3.50
0.00 0.00
Velocity (fUsec) :
0.06
0.00 0.00
Computed Flow Time (min):
25.99
0.00 0.00
Flowpath
Flowpath Flowpath
Shallow Concentrated Flow Computations
A
B C
Flow Length (ft):
1531.55
0.00 0.00
Slope (%):
3.06
0.00 0.00
Surface Type
Unpaved
Unpaved Unpaved
Velocity (fUsec)
2.82
0.00 0.00
Computed Flow Time (min):
9.05
0.00 0.00
Total TOC (min) .................. 35.04
Subbasin Runoff Results
Total Rainfall (in) ............................................................
6.10
Total Runoff (in) .............................................................
3.04
Peak Runoff (cfs) ...........................................................
41.46
Weighted Curve Number ...............................................
71.63
Time of Concentration (days hh:mm:ss) ........................
0003502

Pre -Development 025 - Year Page 8
Subbasin : SUB-02
9
8.5
8
7.5
7
6.6
6
5.5
5
4.5
4
ry
3 F,
3
2.5
2
1.5
0 F,
44
42
40
38
36
34
32
30
28
26
24
22
o
20
ry 18
16
14
12
10
8
6
4
2
Rainfall Intensity Graph
0 1 2 3 4 F, 6 7 a 9 in 11 12 13 14 1 F, 16 17 18 19 20 21 22 23
Time (hrs)
Runoff Hydrograph
01234567891011121314151617181920212223
Time (hrs)

Pre -Development 050 - Year Page 1
Project Description
File Name .................................................... 27842.0002 - Pre Development.SPF
Project Options
Flow Units ...................................................
CIFS
Elevation Type ............................................
Elevation
Hydrology Method .......................................
SCS TR-55
Time of Concentration (TOC) Method ........
SCS TR-55
Link Routing Method ...................................
Hydrodynamic
Enable Overflow Poncling at Nodes ............
YES
Skip Steady State Analysis Time Periods
NO
Analysis Options
Start Analysis On ........................................
Dec 03, 2019
000000
End Analysis On ..........................................
Dec 04, 2019
000000
Start Reporting On ......................................
Dec 03, 2019
000000
Antecedent Dry Days ..................................
0
days
Runoff (Dry Weather) Time Step ................
001 0000
days hh:mm:ss
Runoff (Wet Weather) Time Step ...............
0000500
days hh:mm:ss
Reporting Time Step ...................................
0000500
days hh:mm:ss
Routing Time Step ......................................
15
seconds
Number of Elements
Qty
RainGages .................................................
1
Subbasins....................................................
2
Nodes...........................................................
2
Junctions --------------------------------------------
0
Outfalls -----------------------------------------------
2
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
SIN 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 NorthCarolina Union 50 6.90 SCS Type 11 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-01
63.74 484.00 75.96
6.90
4.16
265.41 208.73
0 003613
2 SUB-02
17.12 484.00 71.63
6.90
3.71
63.44 50.84
0 003502

Pre -Development 050 - Year Page 3
Node Summary
SIN Element Element
Invert Ground/Rim
Initial Surcharge Poncled Peak Max HGL
Max
Min Time of
Total Total Time
ID Type
Elevation
(Max)
Water Elevation Area Inflow Elevation Surcharge Freeboard Peak
Flooded Flooded
Elevation Elevation Attained
Depth
Attained Flooding
Volume
Attained
Occurrence
(ft)
(ft)
(ft) (ft) (ft') (cfs) (ft)
(ft)
(ft) (days hh:mm)
(ac-in) (min)
1 Out-01 Outfall
540.00
0.00 0.00
2 Out-02 Outfall
556.00
0.00 0.00

Pre -Development 050 - Year
Subbasin Hydrology
Page 4
Subbasin : SUB-01
Input Data
Area(ac) ........................................................................
63.74
Peak Rate Factor ...........................................................
484.00
Weighted Curve Number ...............................................
75.96
Rain Gage I D .................................................................
Rain Gage-001
Composite Curve Number
Area
Soil
Curve
Soii/Surface Description
(acres)
Group
Number
Woods, Fair
14.32
D
79.00
Woods, Fair
10.68
D
79.00
Pasture, grassland, or range, Good
38.74
C
74.00
Composite Area & Weighted CN
63.74
75.96
Time of Concentration
TOC Method SCSTR-55
Sheet Flow Equation :
Tc = (0.007 * ((n * Lf)^0.8)) / ((PAO.5) * (SfAO.4))
Where
Tc =
Time of Concentration (hr)
n =
Manning's roughness
Lf =Flow
Length (ft)
P =
2 yr, 24 hr Rainfall (inches)
Sf =Slope
(fVft)
Shallow Concentrated Flow Equation
V =
16.1345 (SfAO.5) (unpaved surface)
V =
20.3282 (SfAO.5) (paved surface)
V =
15.0 (SfAO.5) (grassed waterway surface)
V =
10.0 (SfAO.5) (nearly bare & untilled surface)
V =
9 0 (SfAO.5) (cultivated straight rows surface)
V =
7.0 (SfAO.5) (short grass pasture surface)
V =
5.0 (SfAO.5) (woodland surface)
V =
2.5 (SfAO.5) (forest w/heavy litter surface)
Tc
= (U V) / (3600 sec/hr)
Where
Tc Time of Concentration (hr)
Lf Flow Length (ft)
V Velocity (fVsec)
Sf Slope (fVft)
Channel Flow Equation:
* = (1.49 - (RA(2/3)) * (SfAO.5)) / n
* =Aq/Wp
Tc = (U / 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 (fVsec)
Sf =
Slope (ft/ft)
n =
Manning's roughness

Pre -Development
Sheet Flow Computations
Manning's Roughness:
Flow Length (ft):
Slope (%):
2 yr, 24 hr Rainfall (in)
Velocity (ft/sec) :
Computed Flow Time (min):
Shallow Concentrated Flow Computations
Flow Length (ft):
Slope (%):
Surface Type
Velocity (ft/sec)
Computed Flow Time (min):
Total TOC (min) .................. 36.23
Subbasin Runoff Results
050 - Year Page 5
Flowpath Flowpath Flowpath
A B C
0.4 0.00 0.00
100 0.00 0.00
1 0.00 0.00
3.50 0.00 0.00
0.06 0.00 0.00
27.09 0.00 0.00
Flowpath Flowpath Flowpath
A B C
1771 0.00 0.00
4 0.00 0.00
Unpaved Unpaved Unpaved
3.23 0.00 0.00
9.14 0.00 0.00
Total Rainfall (in) ............................................................
6.90
Total Runoff (in) .............................................................
4.16
Peak Runoff (cfs) ...........................................................
208.73
Weighted Curve Number ...............................................
75.96
Time of Concentration (days hh:mm:ss) ........................
0003614

Pre -Development 050 - Year Page 6
Subbasin : SUB-01
8
7.5
7
6.5
6
5.5
5
4.5
ry 4
3.5
3
2.5
2
1.5
1
0.5
220
210
200
190
180
170
160
160
140
130
120
110
o
100
ry
90
an
70
60
60
40
30
20
10
Rainfall Intensity Graph
0 1 2 3 4 F, 6 7 a 9 in 11 12 13 14 1 F, 16 17 18 19 20 21 22 23
Time (hrs)
Runoff Hydrograph
01234567891011121314151617181920212223
Time (hrs)

Pre -Development 050 - Year
Subbasin : SUB-02
Page 7
Input Data
Area(ac) ........................................................................ 17.12
Peak Rate Factor ........................................................... 484.00
Weighted Curve Number ............................................... 71.63
Rain Gage I D ................................................................. Rain Gage-001
Composite Curve Number
Area
Soil Curve
Soil/Surface Description
(acres)
Group Number
Pasture, grassland, or range, Good
14.00
C 74.00
Pasture, grassland, or range, Good
3.12
B 61.00
Composite Area & Weighted CN
17.12
71.63
Time of Concentration
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 (%):
1.11
0.00 0.00
2 yr, 24 hr Rainfall (in)
3.50
0.00 0.00
Velocity (fUsec) :
0.06
0.00 0.00
Computed Flow Time (min):
25.99
0.00 0.00
Flowpath
Flowpath Flowpath
Shallow Concentrated Flow Computations
A
B C
Flow Length (ft):
1531.55
0.00 0.00
Slope (%):
3.06
0.00 0.00
Surface Type
Unpaved
Unpaved Unpaved
Velocity (fUsec)
2.82
0.00 0.00
Computed Flow Time (min):
9.05
0.00 0.00
Total TOC (min) .................. 35.04
Subbasin Runoff Results
Total Rainfall (in) ............................................................
6.90
Total Runoff (in) .............................................................
3.71
Peak Runoff (cfs) ...........................................................
50.84
Weighted Curve Number ...............................................
71.63
Time of Concentration (days hh:mm:ss) ........................
0003502

Pre -Development 050 - Year Page 8
Subbasin : SUB-02
10
9.5
9
8.6
8
7 F,
7
6.5
6
5.5
5
4.5
ry
4
3.6
3
2.5
2
1.6
1
0.6
54
52
50
48
46
44
42
40
30
36
34
32
F 30
28
26
r ' 24
y
22
20
18
16
14
12
in
8
6
4
2
Rainfall Intensity Graph
0 1 2 3 4 F, 6 7 a 9 in 11 12 13 14 1 F, 16 17 18 19 20 21 22 23
Time (hrs)
Runoff Hydrograph
01234567891011121314151617181920212223
Time (hrs)

STORMWATER MANAGEMENT REPORT
CRESSWIND WESLEY CHAPEL - PHASE 02
APPENDix D
POST- DEVELOPMENT
DRAINAGE MAP
A THOMAS & HUTTON

t
0 z
4- g
�Al
'14
III

STORMWATER MANAGEMENT REPORT
CRESSWIND WESLEY CHAPEL - PHASE 02
APPENDix E
POST- DEVELOPMENT CONDITIONS
DRAINAGE CALCULATIONS
A THOMAS & HUTTON

277842.0002
CRESSWIND WESLEY CHAPEL - PHASE 02
POST -DEVELOPMENT BASINS MODEL

Post -Development 002 - Year Page 1
Project Description
File Name .................................................... 27842.0002 - Post Development.SPF
Project Options
Flow Units ...................................................
CIFS
Elevation Type ............................................
Elevation
Hydrology Method .......................................
SCS TR-55
Time of Concentration (TOC) Method ........
SCS TR-55
Link Routing Method ...................................
Hydrodynamic
Enable Overflow Poncling at Nodes ............
YES
Skip Steady State Analysis Time Periods
NO
Analysis Options
Start Analysis On ........................................
Dec 03, 2020
000000
End Analysis On ..........................................
Dec 04, 2020
000000
Start Reporting On ......................................
Dec 03, 2020
000000
Antecedent Dry Days ..................................
0
days
Runoff (Dry Weather) Time Step ................
001 0000
days hh:mm:ss
Runoff (Wet Weather) Time Step ...............
0000500
days hh:mm:ss
Reporting Time Step ...................................
0000500
days hh:mm:ss
Routing Time Step ......................................
1
seconds
Number of Elements
Qty
RainGages .................................................
1
Subbasins....................................................
3
Nodes...........................................................
5
Junctions --------------------------------------------
2
Outfalls -----------------------------------------------
2
Flow Diversions ----------------------------------
0
Inlets---------------------------------------------------
0
Storage Nodes -----------------------------------
1
Links.............................................................
6
Channels --------------------------------------------
1
Pipes--------------------------------------------------
1
Pumps------------------------------------------------
0
Orifices-----------------------------------------------
2
Weirs--------------------------------------------------
2
Outlets------------------------------------------------
0
Pollutants....................................................
0
LandUses ...................................................
0
Rainfall Details
SIN 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 NorthCarolina 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 POST-DEVELOPMENT-BASIN-SUB-01B
45.50
484.00
85.92
3.50
2.09
95.19 98.63
0 000500
2 UNDISTURBED-BASIN-SUB-01A
23.79
484.00
79.00
3.50
1.57
37.25 22.56
0 003657
3 UNDISTURBED-BASIN-SUB-02
13.14
484.00
70.54
3.50
1.04
13.64 8.32
0 003148

Post -Development 002 - Year Page 3
Node Summary
SIN Element Element
Invert Ground/Rim
Initial Surcharge Poncled Peak Max HGL
Max
Min
Time of
Total Total Time
ID
Type
Elevation
(Max)
Water
Elevation
Area I nflow
Elevation Surcharge Freeboard
Peak Flooded
Flooded
Elevation Elevation
Attained
Depth
Attained
Flooding
Volume
Attained
Occurrence
(ft)
(ft)
(ft)
(ft)
(ft) (cfs)
(ft)
(ft)
(ft)
(days hh:mm)
(ac-in)
(min)
1 CS
Junction
555.00
570.20
558.00
999.00
0.00 43.89
558.00
0.00
12.20
0 0000
0.00
0.00
2 Jun-03
Junction
559.00
570.20
559.00
999.00
0.00 21.64
559.79
0.00
10.41
0 0000
0.00
0.00
3 Out-01
Outfall
553.30
59.58
553.30
4 Out-02
Outfall
560.00
8.32
560.00
5 Pond-03 Storage Node
559.00
571.50
565.00
0.00 97.05
567.99
0.00
0.00

0
0
E
0
0
0-
w o
0 1
w 0
w 1 0 0
E w 00
E o o
0
0 m m
0 0
m o o
0
W 0
3:
0 M. 0
0
>
3:.o m
o 0 00
o o
0
w
0 0 N
mo t000 00
W
M 0 0 0
0 N
ol
�2 0
00
00
0
0 0 00
0 0 0 0
W 0000
z N 00
E 0
m
. C,
w
00
00
m 0 00
> 00
E000000
om0000
0 � m m 0 m
> 000000
w 000000
w
Z4,fg E000000
Ew000000
>
000000
000000
w
0 0
tt� 0 0
00
00
C? C? C?
U)
0
U)
0 0 0
m
m C? C? C? C?
E C? . . . .
2w.'o U)
C? C?
w m w m
C? I C? <
N E In
0 C?
E wE W
U) w 0 0 U')
U)
r

Post -Development 002 - Year
Subbasin Hydrology
Page 5
Subbasin : POST-DEVELOPMENT-BASIN-SUB-01B
Input Data
Area(ac) ........................................................................
45.50
Peak Rate Factor ...........................................................
484.00
Weighted Curve Number ...............................................
85.92
Rain Gage I D .................................................................
Rain Gage-001
Composite Curve Number
Area
Soil
Curve
Sol/Surface Description
(acres)
Group
Number
Paved parking & roofs
13.67
B
98.00
� 75% grass cover, Good
14.69
B
61.00
Future -Paved parking & roofs
16.63
B
98.00
Composite Area & Weighted CN
44.99
85.92
Time of Concentration
TOC Method SCSTR-55
Sheet Flow Equation :
Tc = (0.007 * ((n * Lf)^0.8)) / ((PAO.5) * (SfAO.4))
Where
Tc =
Time of Concentration (hr)
n =
Manning's roughness
Lf =Flow
Length (ft)
P =
2 yr, 24 hr Rainfall (inches)
Sf =Slope
(fVft)
Shallow Concentrated Flow Equation
V =
16.1345 (SfAO.5) (unpaved surface)
V =
20.3282 (SfAO.5) (paved surface)
V =
15.0 (SfAO.5) (grassed waterway surface)
V =
10.0 (SfAO.5) (nearly bare & untilled surface)
V =
9 0 (SfAO.5) (cultivated straight rows surface)
V =
7.0 (SfAO.5) (short grass pasture surface)
V =
5.0 (SfAO.5) (woodland surface)
V =
2.5 (SfAO.5) (forest w/heavy litter surface)
Tc
= (Lf V) / (3600 sec/hr)
Where
Tc Time of Concentration (hr)
Lf Flow Length (ft)
V Velocity (fVsec)
Sf Slope (fVft)
Channel Flow Equation:
* = (1.49 - (RA(2/3)) * (SfAO.5)) / n
* =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 (fVsec)
Sf =
Slope (ft/ft)
n =
Manning's roughness
User -Defined TOC override (minutes): 5.00
Subbasin Runoff Results
Total Rainfall (in) ............................................................ 3.50
Total Runoff (in) ............................................................. 2.09
Peak Runoff (cfs) ........................................................... 98.63
Weighted Curve Number ............................................... 85.92
Time of Concentration (days hh:mm:ss) ........................ 0000500

Post -Development 002 - Year Page 6
Subbasin : POST-DEVELOPMENT-BASIN-SUB-01B
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
-E 1.4
r m 1.3
y
1.2
1.1
1
0.9
0.8
0.7
06
0.5
0.4
0.3
0.2
0.1
105
100
95
90
05
80
75
70
65
60
55
50
45
40
35
30
25
20
15
10
5
Rainfall Intensity Graph
0 1 2 3 4 41 6 7 a 9 in 11 12 13 14 1 F, 16 17 18 19 20 21 22 23
Time (hrs)
Ru n off Hyd ro g raph
01234567891011121314151617181920212223
Time (hrs)

Post -Development 002 - Year
Subbasin : UNDISTURBED-BASIN-SUB-01A
Page 7
Input Data
Area(ac) ........................................................................ 23.79
Peak Rate Factor ........................................................... 484.00
Weighted Curve Number ............................................... 79.00
Rain Gage I D ................................................................. Rain Gage-001
Composite Curve Number
Area
Soil Curve
Soil/Surface Description
(acres)
Group Number
Woods, Fair
23.79
D 79.00
Composite Area & Weighted CN
23.79
79.00
Time of Concentration
Subarea
Subarea
Subarea
Sheet Flow Computations
A
B
C
Manning's Roughness:
.4
0.00
0.00
Flow Length (ft):
100
0.00
0.00
Slope (%):
9.5
0.00
0.00
2 yr, 24 hr Rainfall (in)
3.50
0.00
0.00
Velocity (fUsec) :
0.15
0.00
0.00
Computed Flow Time (min)
11.01
0.00
0.00
Subarea
Subarea
Subarea
Shallow Concentrated Flow Computations
A
B
C
Flow Length (ft):
1370
0.00
0.00
Slope (%):
.3
0.00
0.00
Surface Type
Unpaved
Unpaved
Unpaved
Velocity (fUsec)
0.88
0.00
0.00
Computed Flow Time (min):
25.95
0.00
0.00
Total TOC (min) .................. 36.96
Subbasin Runoff Results
Total Rainfall (in) ............................................................
3.50
Total Runoff (in) .............................................................
1.57
Peak Runoff (cfs) ...........................................................
22.56
Weighted Curve Number ...............................................
79.00
Time of Concentration (days hh:mm:ss) ........................
0003658

Post -Development 002 - Year Page 8
Subbasin : UNDISTURBED-BASIN-SUB-01A
3.1
3
2.9
28
2.7
2.6
2.5
24
2.3
2.2
2.1
2
1.9
1.8
E 1.7
1.6
1.6
1 4
ry 1.3
1.2
1 1
1
0.9
0.8
0.7
0.6
0.5
04
0.3
0.2
0 1
24
23
22
21
20
19
18
17
16
15
14
13
12
o
11 11
ch 10
9
8
7
6
F,
4
3
2
1
Rainfall Intensity Graph
0 1 2 3 4 41 6 7 a 9 in 11 12 13 14 1 F, 16 17 18 19 20 21 22 23
Time (hrs)
Ru n off Hyd ro g raph
01234567891011121314151617181920212223
Time (hrs)

Post -Development 002 - Year
Subbasin : UNDISTURBED-BASIN-SUB-02
Page 9
Input Data
Area(ac) ........................................................................ 13.14
Peak Rate Factor ........................................................... 484.00
Weighted Curve Number ............................................... 70.54
Rain Gage I D ................................................................. Rain Gage-001
Composite Curve Number
Area
Soil Curve
Soil/Surface Description
(acres)
Group Number
Pasture, grassland, or range, Good
3.13
B 61.00
9.65
74.00
0.37
61.00
Composite Area & Weighted CN
13.15
70.54
Time of Concentration
Sheet Flow Computations
Manning's Roughness:
Flow Length (ft):
Slope (%):
2 yr, 24 hr Rainfall (in)
Velocity (fUsec) :
Computed Flow Time (min):
Total TOC (min) .................. 31.80
Subbasin Runoff Results
Subarea
Subarea
Subarea
A
B
C
.4
0.00
0.00
100
0.00
0.00
.67
0.00
0.00
3.50
0.00
0.00
0.05
0.00
0.00
31.80
0.00
0.00
Total Rainfall (in) ............................................................
3.50
Total Runoff (in) .............................................................
1.04
Peak Runoff (cfs) ...........................................................
8.32
Weighted Curve Number ...............................................
70.54
Time of Concentration (days hh:mm:ss) ........................
00031 48

Post -Development 002 - Year Page 10
Subbasin : UNDISTURBED-BASIN-SUB-02
3.1
3
2.9
28
2.7
2.6
2.5
24
2.3
2.2
2.1
2
1.9
1.8
E 1.7
1.6
1.6
1 4
ry 1.3
1.2
1 1
1
0.9
0.8
0.7
0.6
0.5
04
0.3
0.2
0 1
9
7.5
7
6.5
6
5.5
4.5
o
4
ry
3.5
3
2.5
2
1.5
1
0.5
Rainfall Intensity Graph
0 1 2 3 4 41 6 7 a 9 in 11 12 13 14 1 F, 16 17 18 19 20 21 22 23
Time (hrs)
Ru n off Hyd ro g raph
01234567891011121314151617181920212223
Time (hrs)

Post -Development 002 - Year Page 11
Channel Input
SIN Element Length Inlet Inlet
Outlet Outlet Total Average Shape
Height Width Manning's Entrance Exit/Bend Additional Initial Flap
ID Invert Invert
Invert Invert Drop
Slope
Roughness Losses Losses Losses Flow Gate
Elevation Offset Elevation Offset
(ft) (ft) (ft)
(ft) (ft) (ft)
(%)
(ft) (ft) (cfs)
1 Link-02 50.00 555.00 0.00
554.90 1.60 0.10
0.2000 Rectangular
2.000 5.000 0.0010 0.5000 0.5000 0.0000 0.00 No

Post -Development 002 - Year Page 12
Channel Results
SN Element Peak Time of Design Flow Peak Flow/ Peak Flow Travel Peak Flow Peak Flow Total Time Froucle Reported
ID Flow Peak Flow Capacity Design Flow Velocity Time Depth Depth/ Surcharged NumberConclition
Occurrence Ratio Total Depth
Ratio
(cfs) (days hh:mm) (cfs) (fUsec) (min) (ft) (min)
1 Link-02 59.58 0 0000 712.92 0.08 15.05 0.06 0.97 0.59 0.00

Post -Development 002 - Year Page 13
Pipe Input
SIN Element Length Inlet Inlet Outlet Outlet Total Average Pipe Pipe Pipe Manning's Entrance Exit/Bend Additional Initial Flap
ID Invert Invert Invert Invert Drop Slope Shape Diameteror Width Roughness Losses Losses Losses Flow Gate
Elevation Offset Elevation Offset Height
(ft) (ft) (ft) (ft) (ft) (ft) (%) (in) (in) (cfs)
1 Outlet-Pipe-03 65.00 559.00 0.00 555.00 0.00 4.00 6.1500 CIRCULAR 42.000 42.000 0.0130 0.5000 0.5000 0.0000 0.00 No

Post -Development 002 - Year Page 14
No. of
Barrels

Post -Development 002 - Year Page 15
Pipe Results
SN Element Peak Time of Design Flow Peak Flow/ Peak Flow Travel Peak Flow Peak Flow Total Time Froucle Reported
ID Flow Peak Flow Capacity Design Flow Velocity Time Depth Depth/ Surcharged NumberConclition
Occurrence Ratio Total Depth
Ratio
(cfs) (days hh:mm) (cfs) (fUsec) (min) (ft) (min)
1 Outlet-Pipe-03 21.64 0 1235 249.58 0.09 8.98 0.12 1.21 0.43 0.00 Calculated

Post -Development 002 - Year Page 16
Storage Nodes
Storage Node : Pond-03
Input Data
Invert Elevation (ft) ....................................................................
559.00
Max (Rim) Elevation (ft) ............................................................
571.50
Max (Rim) Offset (ft) .................................................................
12.50
Initial Water Elevation (ft) ..........................................................
565.00
Initial Water Depth (ft) ...............................................................
6.00
Poncled Area (ft2) .......................................................................
0.00
Evaporation Loss .......................................................................
0.00
OutflowWeirs
SIN Element
Weir Flap
Crest
Crest
Length
WeirTotal Discharge
ID
Type Gate
Elevation
Offset
Height Coefficient
(ft)
(ft)
(ft)
(ft)
1 Spillway-03
Trapezoidal No
571.00
12.00
50.00
0.50 3.33
2 Weir-03A
Rectangular No
566.80
7.80
5.00
1.20 3.33
Outflow Orifices
SIN 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-03 Bottom
Rectangular No
60.00
60.00
568.00 0.63
2 WQ-Orifice-03 Side
CIRCULAR No
5.00
565.00 0.61
Output Summary Results
Peak Inflow (cfs) ........................................................................
97.05
Peak Lateral Inflow (cfs) ............................................................
97.05
Peak Outflow (cfs) .....................................................................
21.64
Peak Exfiftration Flow Rate (cfm) ..............................................
0.00
Max HGL Elevation Attained (ft) ................................................
567.99
Max HGL Depth Attained (ft) .....................................................
8.99
Average HGL Elevation Attained (ft) .........................................
566.13
Average HGL Depth Attained (ft) ..............................................
7.13
Time of Max HGL Occurrence (days hh:mm) ...........................
0 1235
Total Exfiltration Volume (1 000-ft3) ...........................................
0.000
Total Flooded Volume (ac-in) ....................................................
0
Total Time Flooded (min) ..........................................................
0
Total Retention Time (sec) ........................................................
0.00

Post -Development 010 - Year Page 1
Project Description
File Name .................................................... 27842.0002 - Post Development.SPF
Project Options
Flow Units ...................................................
CIFS
Elevation Type ............................................
Elevation
Hydrology Method .......................................
SCS TR-55
Time of Concentration (TOC) Method ........
SCS TR-55
Link Routing Method ...................................
Hydrodynamic
Enable Overflow Poncling at Nodes ............
YES
Skip Steady State Analysis Time Periods
NO
Analysis Options
Start Analysis On ........................................
Dec 03, 2020
000000
End Analysis On ..........................................
Dec 04, 2020
000000
Start Reporting On ......................................
Dec 03, 2020
000000
Antecedent Dry Days ..................................
0
days
Runoff (Dry Weather) Time Step ................
001 0000
days hh:mm:ss
Runoff (Wet Weather) Time Step ...............
0000500
days hh:mm:ss
Reporting Time Step ...................................
0000500
days hh:mm:ss
Routing Time Step ......................................
1
seconds
Number of Elements
Qty
RainGages .................................................
1
Subbasins....................................................
3
Nodes...........................................................
5
Junctions --------------------------------------------
2
Outfalls -----------------------------------------------
2
Flow Diversions ----------------------------------
0
Inlets---------------------------------------------------
0
Storage Nodes -----------------------------------
1
Links.............................................................
6
Channels --------------------------------------------
1
Pipes--------------------------------------------------
1
Pumps------------------------------------------------
0
Orifices-----------------------------------------------
2
Weirs--------------------------------------------------
2
Outlets------------------------------------------------
0
Pollutants....................................................
0
LandUses ...................................................
0
Rainfall Details
SIN 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 NorthCarolina 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 POST-DEVELOPMENT-BASIN-SUB-01B
45.50
484.00
85.92
5.20
3.65
165.89 167.52
0 000500
2 UNDISTURBED-BASIN-SUB-01A
23.79
484.00
79.00
5.20
2.98
70.77 43.39
0 003657
3 UNDISTURBED-BASIN-SUB-02
13.14
484.00
70.54
5.20
2.23
29.30 18.96
0 003148

Post -Development 010 - Year Page 3
Node Summary
SIN Element Element
Invert Ground/Rim
Initial Surcharge Poncled
Peak Max HGL
Max
Min
Time of
Total Total Time
ID
Type
Elevation
(Max)
Water
Elevation
Area
I nflow
Elevation Surcharge Freeboard
Peak Flooded
Flooded
Elevation Elevation
Attained
Depth
Attained
Flooding
Volume
Attained
Occurrence
(ft)
(ft)
(ft)
(ft)
(ft')
(cfs)
(ft)
(ft)
(ft)
(days hh:mm)
(ac-in)
(min)
1 CS
Junction
555.00
570.20
558.00
999.00
0.00
129.39
561.01
0.00
9.19
0 0000
0.00
0.00
2 Jun-03
Junction
559.00
570.20
559.00
999.00
0.00
94.90
563.04
0.00
7.16
0 0000
0.00
0.00
3 Out-01
Outfall
553.30
129.37
553.30
4 Out-02
Outfall
560.00
18.85
560.00
5 Pond-03 Storage Node
559.00
571.50
565.00
0.00
165.82
568.94
0.00
0.00

0
E
0
0
0-
o
0
w 0 D
Ir 0 U)
w , 0 0
E w 0 0
—0 0
0
0 00
0 � 00
w m —0
1 Ir
m
0
0
3:
0 w cq
0
>
3:.o
0 0 4,� M
0 0
0
'3:
mo t�MNMOM
W
m 0 0 m
N 0
0 c
�2 0
0 0
00
0
0 0 0 0
0 0 0 0
W 0000
z N 0 0
E 0
m
. C,
w
00
00
m 0 00
> 00
g000000
om0000
0 � m m 0 m
> 000000
w 000000
w
Z4,fg g000000
-Ew000000
>
000000
000000
w
0 0
tt� 0 0
00
00
C? C? C?
U)
0
U)
0 0 0
C? C? C? C?
E C? . . . .
2 'o U) 'o 'o 'o 'o
C? C?
C? I C? <
N E In
0 C?
E wE
U) w 0 0 ?: U') ?:
U)
r

Post -Development 010 - Year
Subbasin Hydrology
Page 5
Subbasin : POST-DEVELOPMENT-BASIN-SUB-01B
Input Data
Area(ac) ........................................................................
45.50
Peak Rate Factor ...........................................................
484.00
Weighted Curve Number ...............................................
85.92
Rain Gage I D .................................................................
Rain Gage-001
Composite Curve Number
Area
Soil
Curve
Sol/Surface Description
(acres)
Group
Number
Paved parking & roofs
13.67
B
98.00
� 75% grass cover, Good
14.69
B
61.00
Future -Paved parking & roofs
16.63
B
98.00
Composite Area & Weighted CN
44.99
85.92
Time of Concentration
TOC Method SCSTR-55
Sheet Flow Equation :
Tc = (0.007 * ((n * Lf)^0.8)) / ((PAO.5) * (SfAO.4))
Where
Tc =
Time of Concentration (hr)
n =
Manning's roughness
Lf =Flow
Length (ft)
P =
2 yr, 24 hr Rainfall (inches)
Sf =Slope
(fVft)
Shallow Concentrated Flow Equation
V =
16.1345 (SfAO.5) (unpaved surface)
V =
20.3282 (SfAO.5) (paved surface)
V =
15.0 (SfAO.5) (grassed waterway surface)
V =
10.0 (SfAO.5) (nearly bare & untilled surface)
V =
9 0 (SfAO.5) (cultivated straight rows surface)
V =
7.0 (SfAO.5) (short grass pasture surface)
V =
5.0 (SfAO.5) (woodland surface)
V =
2.5 (SfAO.5) (forest w/heavy litter surface)
Tc
= (Lf V) / (3600 sec/hr)
Where
Tc Time of Concentration (hr)
Lf Flow Length (ft)
V Velocity (fVsec)
Sf Slope (fVft)
Channel Flow Equation:
* = (1.49 - (RA(2/3)) * (SfAO.5)) / n
* =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 (fVsec)
Sf =
Slope (ft/ft)
n =
Manning's roughness
User -Defined TOC override (minutes): 5.00
Subbasin Runoff Results
Total Rainfall (in) ............................................................ 5.20
Total Runoff (in) ............................................................. 3.65
Peak Runoff (cfs) ........................................................... 167.52
Weighted Curve Number ............................................... 85.92
Time of Concentration (days hh:mm:ss) ........................ 0000500

Post -Development 010 - Year Page 6
Subbasin : POST-DEVELOPMENT-BASIN-SUB-01B
4.4
4.2
4
3.8
3.6
3.4
3.2
3
2.8
2.6
E 2.4
2.2
S 2
1.8
1.6
1 4
1.2
1
0.8
0.6
0.4
02
100
170
160
150
140
130
120
110
100
90
o
r 1 80
y
70
60
50
40
30
20
10
Rainfall Intensity Graph
0 1 2 3 4 41 6 7 a 9 in 11 12 13 14 1 F, 16 17 18 19 20 21 22 23
Time (hrs)
Ru n off Hyd ro g raph
01234567891011121314151617181920212223
Time (hrs)

Post -Development 010 - Year
Subbasin : UNDISTURBED-BASIN-SUB-01A
Page 7
Input Data
Area(ac) ........................................................................ 23.79
Peak Rate Factor ........................................................... 484.00
Weighted Curve Number ............................................... 79.00
Rain Gage I D ................................................................. Rain Gage-001
Composite Curve Number
Area
Soil Curve
Soil/Surface Description
(acres)
Group Number
Woods, Fair
23.79
D 79.00
Composite Area & Weighted CN
23.79
79.00
Time of Concentration
Subarea
Subarea
Subarea
Sheet Flow Computations
A
B
C
Manning's Roughness:
.4
0.00
0.00
Flow Length (ft):
100
0.00
0.00
Slope (%):
9.5
0.00
0.00
2 yr, 24 hr Rainfall (in)
3.50
0.00
0.00
Velocity (fUsec) :
0.15
0.00
0.00
Computed Flow Time (min)
11.01
0.00
0.00
Subarea
Subarea
Subarea
Shallow Concentrated Flow Computations
A
B
C
Flow Length (ft):
1370
0.00
0.00
Slope (%):
.3
0.00
0.00
Surface Type
Unpaved
Unpaved
Unpaved
Velocity (fUsec)
0.88
0.00
0.00
Computed Flow Time (min):
25.95
0.00
0.00
Total TOC (min) .................. 36.96
Subbasin Runoff Results
Total Rainfall (in) ............................................................
5.20
Total Runoff (in) .............................................................
2.98
Peak Runoff (cfs) ...........................................................
43.39
Weighted Curve Number ...............................................
79.00
Time of Concentration (days hh:mm:ss) ........................
0003658

Post -Development 010 - Year Page 8
Subbasin : UNDISTURBED-BASIN-SUB-01A
4.6
4.4
4.2
4
3.8
3.6
3.4
3.2
3
2.8
2.6
Z 4
2.2
2
ry
1.8
1.6
1.4
1.2
1
0.8
0.6
0.4
0.2
46
44
42
40
38
36
34
32
30
20
-u� 26
24
22
20
10
16
14
12
10
a
6
4
2
Rai nfal I I nte n s ity G rap h
0 1 2 3 4 41 6 7 a 9 in 11 12 13 14 1 F, 16 17 18 19 20 21 22 23
Time (hrs)
Ru n off Hyd ro g raph
01234567891011121314151617181920212223
Time (hrs)

Post -Development 010 - Year
Subbasin : UNDISTURBED-BASIN-SUB-02
Page 9
Input Data
Area(ac) ........................................................................ 13.14
Peak Rate Factor ........................................................... 484.00
Weighted Curve Number ............................................... 70.54
Rain Gage I D ................................................................. Rain Gage-001
Composite Curve Number
Area
Soil Curve
Soil/Surface Description
(acres)
Group Number
Pasture, grassland, or range, Good
3.13
B 61.00
9.65
74.00
0.37
61.00
Composite Area & Weighted CN
13.15
70.54
Time of Concentration
Sheet Flow Computations
Manning's Roughness:
Flow Length (ft):
Slope (%):
2 yr, 24 hr Rainfall (in)
Velocity (fUsec) :
Computed Flow Time (min):
Total TOC (min) .................. 31.80
Subbasin Runoff Results
Subarea
Subarea
Subarea
A
B
C
.4
0.00
0.00
100
0.00
0.00
.67
0.00
0.00
3.50
0.00
0.00
0.05
0.00
0.00
31.80
0.00
0.00
Total Rainfall (in) ............................................................
5.20
Total Runoff (in) .............................................................
2.23
Peak Runoff (cfs) ...........................................................
18.96
Weighted Curve Number ...............................................
70.54
Time of Concentration (days hh:mm:ss) ........................
00031 48

Post -Development 010 - Year Page 10
Subbasin : UNDISTURBED-BASIN-SUB-02
4.6
4.4
4.2
4
3.8
3.6
3.4
3.2
3
2.8
2.6
Z 4
2.2
2
ry
1.8
1.6
1.4
1.2
1
0.8
0.6
0.4
0.2
20
19
18
17
16
15
14
13
12
11
10
o
ry
7
6
5
4
3
2
1
Rai nfal I I nte n s ity G rap h
0 1 2 3 4 41 6 7 a 9 in 11 12 13 14 1 F, 16 17 18 19 20 21 22 23
Time (hrs)
Ru n off Hyd ro g raph
01234567891011121314151617181920212223
Time (hrs)

Post -Development 010 - Year Page 11
Channel Input
SIN Element Length Inlet Inlet
Outlet Outlet Total Average Shape
Height Width Manning's Entrance Exit/Bend Additional Initial Flap
ID Invert Invert
Invert Invert Drop
Slope
Roughness Losses Losses Losses Flow Gate
Elevation Offset Elevation Offset
(ft) (ft) (ft)
(ft) (ft) (ft)
(%)
(ft) (ft) (cfs)
1 Link-02 50.00 555.00 0.00
554.90 1.60 0.10
0.2000 Rectangular
2.000 5.000 0.0010 0.5000 0.5000 0.0000 0.00 No

Post -Development 010 - Year Page 12
Channel Results
SN Element Peak Time of Design Flow Peak Flow/ Peak Flow Travel Peak Flow Peak Flow Total Time Froucle Reported
ID Flow Peak Flow Capacity Design Flow Velocity Time Depth Depth/ Surcharged NumberConclition
Occurrence Ratio Total Depth
Ratio
(cfs) (days hh:mm) (cfs) (fUsec) (min) (ft) (min)
1 Link-02 129.37 0 1221 712.92 0.18 19.75 0.04 1.31 0.66 0.00

Post -Development 010 - Year Page 13
Pipe Input
SIN Element Length Inlet Inlet Outlet Outlet Total Average Pipe Pipe Pipe Manning's Entrance Exit/Bend Additional Initial Flap
ID Invert Invert Invert Invert Drop Slope Shape Diameteror Width Roughness Losses Losses Losses Flow Gate
Elevation Offset Elevation Offset Height
(ft) (ft) (ft) (ft) (ft) (ft) (%) (in) (in) (cfs)
1 Outlet-Pipe-03 65.00 559.00 0.00 555.00 0.00 4.00 6.1500 CIRCULAR 42.000 42.000 0.0130 0.5000 0.5000 0.0000 0.00 No

Post -Development 010 - Year Page 14
No. of
Barrels

Post -Development 010 - Year Page 15
Pipe Results
SN Element Peak Time of Design Flow Peak Flow/ Peak Flow Travel Peak Flow Peak Flow Total Time Froucle Reported
ID Flow Peak Flow Capacity Design Flow Velocity Time Depth Depth/ Surcharged NumberConclition
Occurrence Ratio Total Depth
Ratio
(cfs) (days hh:mm) (cfs) (fUsec) (min) (ft) (min)
1 Outlet-Pipe-03 94.78 0 1218 249.58 0.38 9.85 0.11 3.50 1.00 10.00 SURCHARGED

Post -Development 010 - Year Page 16
Storage Nodes
Storage Node : Pond-03
Input Data
Invert Elevation (ft) ....................................................................
559.00
Max (Rim) Elevation (ft) ............................................................
571.50
Max (Rim) Offset (ft) .................................................................
12.50
Initial Water Elevation (ft) ..........................................................
565.00
Initial Water Depth (ft) ...............................................................
6.00
Poncled Area (ft2) .......................................................................
0.00
Evaporation Loss .......................................................................
0.00
OutflowWeirs
SIN Element
Weir Flap
Crest
Crest
Length
WeirTotal Discharge
ID
Type Gate
Elevation
Offset
Height Coefficient
(ft)
(ft)
(ft)
(ft)
1 Spillway-03
Trapezoidal No
571.00
12.00
50.00
0.50 3.33
2 Weir-03A
Rectangular No
566.80
7.80
5.00
1.20 3.33
Outflow Orifices
SIN 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-03 Bottom
Rectangular No
60.00
60.00
568.00 0.63
2 WQ-Orifice-03 Side
CIRCULAR No
5.00
565.00 0.61
Output Summary Results
Peak Inflow (cfs) ........................................................................
165.82
Peak Lateral Inflow (cfs) ............................................................
165.82
Peak Outflow (cfs) .....................................................................
94.90
Peak Exfiftration Flow Rate (cfm) ..............................................
0.00
Max HGL Elevation Attained (ft) ................................................
568.94
Max HGL Depth Attained (ft) .....................................................
9.94
Average HGL Elevation Attained (ft) .........................................
566.31
Average HGL Depth Attained (ft) ..............................................
7.31
Time of Max HGL Occurrence (days hh:mm) ...........................
0 1218
Total Exfiltration Volume (1 000-ft3) ...........................................
0.000
Total Flooded Volume (ac-in) ....................................................
0
Total Time Flooded (min) ..........................................................
0
Total Retention Time (sec) ........................................................
0.00

Post -Development 025 - Year Page 1
Project Description
File Name .................................................... 27842.0002 - Post Development.SPF
Project Options
Flow Units ...................................................
CIFS
Elevation Type ............................................
Elevation
Hydrology Method .......................................
SCS TR-55
Time of Concentration (TOC) Method ........
SCS TR-55
Link Routing Method ...................................
Hydrodynamic
Enable Overflow Poncling at Nodes ............
YES
Skip Steady State Analysis Time Periods
NO
Analysis Options
Start Analysis On ........................................
Dec 03, 2020
000000
End Analysis On ..........................................
Dec 04, 2020
000000
Start Reporting On ......................................
Dec 03, 2020
000000
Antecedent Dry Days ..................................
0
days
Runoff (Dry Weather) Time Step ................
001 0000
days hh:mm:ss
Runoff (Wet Weather) Time Step ...............
0000500
days hh:mm:ss
Reporting Time Step ...................................
0000500
days hh:mm:ss
Routing Time Step ......................................
1
seconds
Number of Elements
Qty
RainGages .................................................
1
Subbasins....................................................
3
Nodes...........................................................
5
Junctions --------------------------------------------
2
Outfalls -----------------------------------------------
2
Flow Diversions ----------------------------------
0
Inlets---------------------------------------------------
0
Storage Nodes -----------------------------------
1
Links.............................................................
6
Channels --------------------------------------------
1
Pipes--------------------------------------------------
1
Pumps------------------------------------------------
0
Orifices-----------------------------------------------
2
Weirs--------------------------------------------------
2
Outlets------------------------------------------------
0
Pollutants....................................................
0
LandUses ...................................................
0
Rainfall Details
SIN 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 NorthCarolina 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 POST-DEVELOPMENT-BASIN-SUB-01B
45.50
484.00
85.92
6.10
4.50
204.57 203.91
0 000500
2 UNDISTURBED-BASIN-SUB-01A
23.79
484.00
79.00
6.10
3.77
89.65 54.85
0 003657
3 UNDISTURBED-BASIN-SUB-02
13.14
484.00
70.54
6.10
2.94
38.58 25.20
0 003148

Post -Development 025 - Year Page 3
Node Summary
SIN Element Element
Invert Ground/Rim
Initial Surcharge Poncled Peak Max HGL
Max
Min
Time of
Total Total Time
ID
Type
Elevation
(Max)
Water
Elevation
Area I nflow
Elevation Surcharge Freeboard
Peak Flooded
Flooded
Elevation Elevation
Attained
Depth
Attained
Flooding
Volume
Attained
Occurrence
(ft)
(ft)
(ft)
(ft)
(ft) (cfs)
(ft)
(ft)
(ft)
(days hh:mm)
(ac-in)
(min)
1 CS
Junction
555.00
570.20
558.00
999.00
0.00 172.53
564.13
0.00
6.07
0 0000
0.00
0.00
2 Jun-03
Junction
559.00
570.20
559.00
999.00
0.00 132.53
567.97
0.00
2.23
0 0000
0.00
0.00
3 Out-01
Outfall
553.30
172.45
553.30
4 Out-02
Outfall
560.00
24.96
560.00
5 Pond-03 Storage Node
559.00
571.50
565.00
0.00 202.24
569.31
0.00
0.00

0
E
0
0
0-
o
0
w 0 D
Ir 0 U)
w , 0 0
E w 0 0
0
0
0 0 m
0 � 00
w m —0
1 Ir
m
0
0
3:
0
0
>
3:.o m
0 0 4C� 0
0 0
0
'3: -j��Oomop
m 0 t M M 0
W
N N m 00
�2 �� m m
0 c
�2 0
0 0
00
0
0 0 00
0 0 0 0
W 0000
z N 00
E 0
m
. C,
w
00
00
m 0 00
> 00
g000000
om0000
0 � m m 0 m
> 000000
w 000000
w
Z4,fg g000000
-Ew000000
>
000000
000000
w
0 0
tt� 0 0
00
00
C? C? C?
U)
0
U)
0 0 0
m
m C? C? C? C?
E C? . . . .
2 'o U) 'o 'o 'o 'o
C? C?
m w m
C? I C? <
N E In
0 C?
E wE
U) w 0 0 ?: U') ?:
U)
r

Post -Development 025 - Year
Subbasin Hydrology
Page 5
Subbasin : POST-DEVELOPMENT-BASIN-SUB-01B
Input Data
Area(ac) ........................................................................
45.50
Peak Rate Factor ...........................................................
484.00
Weighted Curve Number ...............................................
85.92
Rain Gage I D .................................................................
Rain Gage-001
Composite Curve Number
Area
Soil
Curve
Sol/Surface Description
(acres)
Group
Number
Paved parking & roofs
13.67
B
98.00
� 75% grass cover, Good
14.69
B
61.00
Future -Paved parking & roofs
16.63
B
98.00
Composite Area & Weighted CN
44.99
85.92
Time of Concentration
TOC Method SCSTR-55
Sheet Flow Equation :
Tc = (0.007 * ((n * Lf)^0.8)) / ((PAO.5) * (SfAO.4))
Where
Tc =
Time of Concentration (hr)
n =
Manning's roughness
Lf =Flow
Length (ft)
P =
2 yr, 24 hr Rainfall (inches)
Sf =Slope
(fVft)
Shallow Concentrated Flow Equation
V =
16.1345 (SfAO.5) (unpaved surface)
V =
20.3282 (SfAO.5) (paved surface)
V =
15.0 (SfAO.5) (grassed waterway surface)
V =
10.0 (SfAO.5) (nearly bare & untilled surface)
V =
9 0 (SfAO.5) (cultivated straight rows surface)
V =
7.0 (SfAO.5) (short grass pasture surface)
V =
5.0 (SfAO.5) (woodland surface)
V =
2.5 (SfAO.5) (forest w/heavy litter surface)
Tc
= (Lf V) / (3600 sec/hr)
Where
Tc Time of Concentration (hr)
Lf Flow Length (ft)
V Velocity (fVsec)
Sf Slope (fVft)
Channel Flow Equation:
* = (1.49 - (RA(2/3)) * (SfAO.5)) / n
* =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 (fVsec)
Sf =
Slope (ft/ft)
n =
Manning's roughness
User -Defined TOC override (minutes): 5.00
Subbasin Runoff Results
Total Rainfall (in) ............................................................ 6.10
Total Runoff (in) ............................................................. 4.50
Peak Runoff (cfs) ........................................................... 203.91
Weighted Curve Number ............................................... 85.92
Time of Concentration (days hh:mm:ss) ........................ 0000500

Post -Development 025 - Year Page 6
Subbasin : POST-DEVELOPMENT-BASIN-SUB-01B
5.2
5
4.8
4.6
4.4
42
4
3.8
3.6
34
3.2
3
E 2.8
2.6
.'E 2.4
m
ry 2.2
2
1.0
1 6
1.4
1.2
1
na
06
0.4
0.2
220
210
200
190
180
170
160
160
140
130
120
110
o
100
ry
90
an
70
60
60
40
30
20
10
Rainfall Intensity Graph
0 1 2 3 4 41 6 7 a 9 in 11 12 13 14 1 F, 16 17 18 19 20 21 22 23
Time (hrs)
Ru n off Hyd ro g raph
01234567891011121314151617181920212223
Time (hrs)

Post -Development 025 - Year
Subbasin : UNDISTURBED-BASIN-SUB-01A
Page 7
Input Data
Area(ac) ........................................................................ 23.79
Peak Rate Factor ........................................................... 484.00
Weighted Curve Number ............................................... 79.00
Rain Gage I D ................................................................. Rain Gage-001
Composite Curve Number
Area
Soil Curve
Soil/Surface Description
(acres)
Group Number
Woods, Fair
23.79
D 79.00
Composite Area & Weighted CN
23.79
79.00
Time of Concentration
Subarea
Subarea
Subarea
Sheet Flow Computations
A
B
C
Manning's Roughness:
.4
0.00
0.00
Flow Length (ft):
100
0.00
0.00
Slope (%):
9.5
0.00
0.00
2 yr, 24 hr Rainfall (in)
3.50
0.00
0.00
Velocity (fUsec) :
0.15
0.00
0.00
Computed Flow Time (min)
11.01
0.00
0.00
Subarea
Subarea
Subarea
Shallow Concentrated Flow Computations
A
B
C
Flow Length (ft):
1370
0.00
0.00
Slope (%):
.3
0.00
0.00
Surface Type
Unpaved
Unpaved
Unpaved
Velocity (fUsec)
0.88
0.00
0.00
Computed Flow Time (min):
25.95
0.00
0.00
Total TOC (min) .................. 36.96
Subbasin Runoff Results
Total Rainfall (in) ............................................................
6.10
Total Runoff (in) .............................................................
3.77
Peak Runoff (cfs) ...........................................................
54.85
Weighted Curve Number ...............................................
79.00
Time of Concentration (days hh:mm:ss) ........................
0003658

Post -Development 025 - Year Page 8
Subbasin : UNDISTURBED-BASIN-SUB-01A
5.4
F, 2
6
4.8
4.6
4.4
4.2
4
3.8
3.6
34
3.2
3
2.0
m 2.b
2.4
2.2
2
1.0
1 6
1 4
1 2
1
0.8
0.6
0.4
0.2
ry
Rai nfal I I nte n s ity G rap h
0 1 2 3 4 41 6 7 a 9 in 11 12 13 14 1 F, 16 17 18 19 20 21 22 23
Time (hrs)
Ru n off Hyd ro g raph
01234567891011121314151617181920212223
Time (hrs)

Post -Development 025 - Year
Subbasin : UNDISTURBED-BASIN-SUB-02
Page 9
Input Data
Area(ac) ........................................................................ 13.14
Peak Rate Factor ........................................................... 484.00
Weighted Curve Number ............................................... 70.54
Rain Gage I D ................................................................. Rain Gage-001
Composite Curve Number
Area
Soil Curve
Soil/Surface Description
(acres)
Group Number
Pasture, grassland, or range, Good
3.13
B 61.00
9.65
74.00
0.37
61.00
Composite Area & Weighted CN
13.15
70.54
Time of Concentration
Sheet Flow Computations
Manning's Roughness:
Flow Length (ft):
Slope (%):
2 yr, 24 hr Rainfall (in)
Velocity (fUsec) :
Computed Flow Time (min):
Total TOC (min) .................. 31.80
Subbasin Runoff Results
Subarea
Subarea
Subarea
A
B
C
.4
0.00
0.00
100
0.00
0.00
.67
0.00
0.00
3.50
0.00
0.00
0.05
0.00
0.00
31.80
0.00
0.00
Total Rainfall (in) ............................................................
6.10
Total Runoff (in) .............................................................
2.94
Peak Runoff (cfs) ...........................................................
25.20
Weighted Curve Number ...............................................
70.54
Time of Concentration (days hh:mm:ss) ........................
00031 48

Post -Development 025 - Year Page 10
Subbasin : UNDISTURBED-BASIN-SUB-02
5.4
F, 2
6
4.8
4.6
4.4
4.2
4
3.8
3.6
34
3.2
3
2.0
m 2.b
2.4
2.2
2
1.0
1 6
1 4
1 2
1
0.8
0.6
0.4
0.2
26
2F,
24
23
22
21
20
19
18
17
16
15
14
13
o
' 12
cl� i i
10
9
0
7
6
5
4
3
2
1
Rainfall Intensity Graph
0 1 2 3 4 41 6 7 a 9 in 11 12 13 14 1 F, 16 17 18 19 20 21 22 23
Time (hrs)
Ru n off Hyd ro g raph
01234567891011121314151617181920212223
Time (hrs)

Post -Development 025 - Year Page 11
Channel Input
SIN Element Length Inlet Inlet
Outlet Outlet Total Average Shape
Height Width Manning's Entrance Exit/Bend Additional Initial Flap
ID Invert Invert
Invert Invert Drop
Slope
Roughness Losses Losses Losses Flow Gate
Elevation Offset Elevation Offset
(ft) (ft) (ft)
(ft) (ft) (ft)
(%)
(ft) (ft) (cfs)
1 Link-02 50.00 555.00 0.00
554.90 1.60 0.10
0.2000 Rectangular
2.000 5.000 0.0010 0.5000 0.5000 0.0000 0.00 No

Post -Development 025 - Year Page 12
Channel Results
SN Element Peak Time of Design Flow Peak Flow/ Peak Flow Travel Peak Flow Peak Flow Total Time Froucle Reported
ID Flow Peak Flow Capacity Design Flow Velocity Time Depth Depth/ Surcharged NumberConclition
Occurrence Ratio Total Depth
Ratio
(cfs) (days hh:mm) (cfs) (fUsec) (min) (ft) (min)
1 Link-02 172.45 0 1220 712.92 0.24 25.09 0.03 1.37 0.69 0.00

Post -Development 025 - Year Page 13
Pipe Input
SIN Element Length Inlet Inlet Outlet Outlet Total Average Pipe Pipe Pipe Manning's Entrance Exit/Bend Additional Initial Flap
ID Invert Invert Invert Invert Drop Slope Shape Diameteror Width Roughness Losses Losses Losses Flow Gate
Elevation Offset Elevation Offset Height
(ft) (ft) (ft) (ft) (ft) (ft) (%) (in) (in) (cfs)
1 Outlet-Pipe-03 65.00 559.00 0.00 555.00 0.00 4.00 6.1500 CIRCULAR 42.000 42.000 0.0130 0.5000 0.5000 0.0000 0.00 No

Post -Development 025 - Year Page 14
No. of
Barrels

Post -Development 025 - Year Page 15
Pipe Results
SN Element Peak Time of Design Flow Peak Flow/ Peak Flow Travel Peak Flow Peak Flow Total Time Froucle Reported
ID Flow Peak Flow Capacity Design Flow Velocity Time Depth Depth/ Surcharged NumberConclition
Occurrence Ratio Total Depth
Ratio
(cfs) (days hh:mm) (cfs) (fUsec) (min) (ft) (min)
1 Outlet-Pipe-03 132.34 0 1214 249.58 0.53 13.75 0.08 3.50 1.00 28.00 SURCHARGED

Post -Development 025 - Year Page 16
Storage Nodes
Storage Node : Pond-03
Input Data
Invert Elevation (ft) ....................................................................
559.00
Max (Rim) Elevation (ft) ............................................................
571.50
Max (Rim) Offset (ft) .................................................................
12.50
Initial Water Elevation (ft) ..........................................................
565.00
Initial Water Depth (ft) ...............................................................
6.00
Poncled Area (ft2) .......................................................................
0.00
Evaporation Loss .......................................................................
0.00
OutflowWeirs
SIN Element
Weir Flap
Crest
Crest
Length
WeirTotal Discharge
ID
Type Gate
Elevation
Offset
Height Coefficient
(ft)
(ft)
(ft)
(ft)
1 Spillway-03
Trapezoidal No
571.00
12.00
50.00
0.50 3.33
2 Weir-03A
Rectangular No
566.80
7.80
5.00
1.20 3.33
Outflow Orifices
SIN 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-03 Bottom
Rectangular No
60.00
60.00
568.00 0.63
2 WQ-Orifice-03 Side
CIRCULAR No
5.00
565.00 0.61
Output Summary Results
Peak Inflow (cfs) ........................................................................
202.24
Peak Lateral Inflow (cfs) ............................................................
202.24
Peak Outflow (cfs) .....................................................................
132.53
Peak Exfiftration Flow Rate (cfm) ..............................................
0.00
Max HGL Elevation Attained (ft) ................................................
569.31
Max HGL Depth Attained (ft) .....................................................
10.31
Average HGL Elevation Attained (ft) .........................................
566.40
Average HGL Depth Attained (ft) ..............................................
7.4
Time of Max HGL Occurrence (days hh:mm) ...........................
0 1216
Total Exfiltration Volume (1 000-ft3) ...........................................
0.000
Total Flooded Volume (ac-in) ....................................................
0
Total Time Flooded (min) ..........................................................
0
Total Retention Time (sec) ........................................................
0.00

Post -Development 050 - Year Page 1
Project Description
File Name .................................................... 27842.0002 - Post Development.SPF
Project Options
Flow Units ...................................................
CIFS
Elevation Type ............................................
Elevation
Hydrology Method .......................................
SCS TR-55
Time of Concentration (TOC) Method ........
SCS TR-55
Link Routing Method ...................................
Hydrodynamic
Enable Overflow Poncling at Nodes ............
YES
Skip Steady State Analysis Time Periods
NO
Analysis Options
Start Analysis On ........................................
Dec 03, 2020
000000
End Analysis On ..........................................
Dec 04, 2020
000000
Start Reporting On ......................................
Dec 03, 2020
000000
Antecedent Dry Days ..................................
0
days
Runoff (Dry Weather) Time Step ................
001 0000
days hh:mm:ss
Runoff (Wet Weather) Time Step ...............
0000500
days hh:mm:ss
Reporting Time Step ...................................
0000500
days hh:mm:ss
Routing Time Step ......................................
1
seconds
Number of Elements
Qty
RainGages .................................................
1
Subbasins....................................................
3
Nodes...........................................................
5
Junctions --------------------------------------------
2
Outfalls -----------------------------------------------
2
Flow Diversions ----------------------------------
0
Inlets---------------------------------------------------
0
Storage Nodes -----------------------------------
1
Links.............................................................
6
Channels --------------------------------------------
1
Pipes--------------------------------------------------
1
Pumps------------------------------------------------
0
Orifices-----------------------------------------------
2
Weirs--------------------------------------------------
2
Outlets------------------------------------------------
0
Pollutants....................................................
0
LandUses ...................................................
0
Rainfall Details
SIN 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 NorthCarolina 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 POST-DEVELOPMENT-BASIN-SUB-01B
45.50
484.00
85.92
6.90
5.26
239.38 236.38
0 000500
2 UNDISTURBED-BASIN-SUB-01A
23.79
484.00
79.00
6.90
4.49
106.88 65.23
0 003657
3 UNDISTURBED-BASIN-SUB-02
13.14
484.00
70.54
6.90
3.59
47.19 30.95
0 003148

Post -Development 050 - Year Page 3
Node Summary
SIN Element Element
Invert Ground/Rim
Initial Surcharge Poncled Peak Max HGL
Max
Min
Time of
Total Total Time
ID
Type
Elevation
(Max)
Water
Elevation
Area I nflow
Elevation Surcharge Freeboard
Peak Flooded
Flooded
Elevation Elevation
Attained
Depth
Attained
Flooding
Volume
Attained
Occurrence
(ft)
(ft)
(ft)
(ft)
(ft) (cfs)
(ft)
(ft)
(ft)
(days hh:mm)
(ac-in)
(min)
1 CS
Junction
555.00
570.20
558.00
999.00
0.00 183.78
565.02
0.00
5.18
0 0000
0.00
0.00
2 Jun-03
Junction
559.00
570.20
559.00
999.00
0.00 137.79
568.43
0.00
1.77
0 0000
0.00
0.00
3 Out-01
Outfall
553.30
183.77
553.30
4 Out-02
Outfall
560.00
30.60
560.00
5 Pond-03 Storage Node
559.00
571.50
565.00
0.00 234.58
569.75
0.00
0.00

0
0
0
E
0
0
0-
o
0
w 0 D
Ir 0 U)
w , 0 0
E w 0 0
0
0
0 00
0 � 0 �
w m —0
1 Ir
m
0 m
0
3:
0.5
0
>
3:.o 00
0 0 4,� 0 N
0 0
0
m 0 m
mo tN�Omoo
W
� m 0- 0
�2 �2 12 m
0 c
�2 0
0 0
00
0
0 0 00
0 0 0 0
W 0000
z N 0 0
E 0
m
. C,
w
00
00
m 0 00
> 00
g000000
om0000
0 � m m 0 m
> 000000
w 000000
w
Z4,fg g000000
—Ew000000
>
000000
000000
w
0 0
tt� 0 0
00
00
C? C? C?
U)
0
U)
0 0 0
C? C? C? C?
E C? . . . .
2 'o U) 'o 'o 'o 'o
C? C?
C? I C? <
N E In
0 C?
E wE
U) w 0 0 ?: U') ?:
U)
r

Post -Development 050 - Year
Subbasin Hydrology
Page 5
Subbasin : POST-DEVELOPMENT-BASIN-SUB-01B
Input Data
Area(ac) ........................................................................
45.50
Peak Rate Factor ...........................................................
484.00
Weighted Curve Number ...............................................
85.92
Rain Gage I D .................................................................
Rain Gage-001
Composite Curve Number
Area
Soil
Curve
Sol/Surface Description
(acres)
Group
Number
Paved parking & roofs
13.67
B
98.00
� 75% grass cover, Good
14.69
B
61.00
Future -Paved parking & roofs
16.63
B
98.00
Composite Area & Weighted CN
44.99
85.92
Time of Concentration
TOC Method SCSTR-55
Sheet Flow Equation :
Tc = (0.007 * ((n * Lf)^0.8)) / ((PAO.5) * (SfAO.4))
Where
Tc =
Time of Concentration (hr)
n =
Manning's roughness
Lf =Flow
Length (ft)
P =
2 yr, 24 hr Rainfall (inches)
Sf =Slope
(fVft)
Shallow Concentrated Flow Equation
V =
16.1345 (SfAO.5) (unpaved surface)
V =
20.3282 (SfAO.5) (paved surface)
V =
15.0 (SfAO.5) (grassed waterway surface)
V =
10.0 (SfAO.5) (nearly bare & untilled surface)
V =
9 0 (SfAO.5) (cultivated straight rows surface)
V =
7.0 (SfAO.5) (short grass pasture surface)
V =
5.0 (SfAO.5) (woodland surface)
V =
2.5 (SfAO.5) (forest w/heavy litter surface)
Tc
= (Lf V) / (3600 sec/hr)
Where
Tc Time of Concentration (hr)
Lf Flow Length (ft)
V Velocity (fVsec)
Sf Slope (fVft)
Channel Flow Equation:
* = (1.49 - (RA(2/3)) * (SfAO.5)) / n
* =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 (fVsec)
Sf =
Slope (ft/ft)
n =
Manning's roughness
User -Defined TOC override (minutes): 5.00
Subbasin Runoff Results
Total Rainfall (in) ............................................................ 6.90
Total Runoff (in) ............................................................. 5.26
Peak Runoff (cfs) ........................................................... 236.38
Weighted Curve Number ............................................... 85.92
Time of Concentration (days hh:mm:ss) ........................ 0000500

Post -Development 050 - Year Page 6
Subbasin : POST-DEVELOPMENT-BASIN-SUB-01B
6
5.0
5.6
5.4
5.2
5
4.8
4.6
4.4
4.2
4
3.0
3.6
�z 3.4
32
3
-E 2.0
r m 2.6
y
2.4
2.2
2
1.8
1.6
1.4
1 2
1
0.8
0.6
0.4
0.2
250
240
230
220
210
200
190
180
170
160
150
140
130
120
ry 110
ion
90
00
70
60
50
40
30
20
10
Rainfall Intensity Graph
0 1 2 3 4 41 6 7 a 9 in 11 12 13 14 1 F, 16 17 18 19 20 21 22 23
Time (hrs)
Ru n off Hyd ro g raph
01234567891011121314151617181920212223
Time (hrs)

Post -Development 050 - Year
Subbasin : UNDISTURBED-BASIN-SUB-01A
Page 7
Input Data
Area(ac) ........................................................................ 23.79
Peak Rate Factor ........................................................... 484.00
Weighted Curve Number ............................................... 79.00
Rain Gage I D ................................................................. Rain Gage-001
Composite Curve Number
Area
Soil Curve
Soil/Surface Description
(acres)
Group Number
Woods, Fair
23.79
D 79.00
Composite Area & Weighted CN
23.79
79.00
Time of Concentration
Subarea
Subarea
Subarea
Sheet Flow Computations
A
B
C
Manning's Roughness:
.4
0.00
0.00
Flow Length (ft):
100
0.00
0.00
Slope (%):
9.5
0.00
0.00
2 yr, 24 hr Rainfall (in)
3.50
0.00
0.00
Velocity (fUsec) :
0.15
0.00
0.00
Computed Flow Time (min)
11.01
0.00
0.00
Subarea
Subarea
Subarea
Shallow Concentrated Flow Computations
A
B
C
Flow Length (ft):
1370
0.00
0.00
Slope (%):
.3
0.00
0.00
Surface Type
Unpaved
Unpaved
Unpaved
Velocity (fUsec)
0.88
0.00
0.00
Computed Flow Time (min):
25.95
0.00
0.00
Total TOC (min) .................. 36.96
Subbasin Runoff Results
Total Rainfall (in) ............................................................
6.90
Total Runoff (in) .............................................................
4.49
Peak Runoff (cfs) ...........................................................
65.23
Weighted Curve Number ...............................................
79.00
Time of Concentration (days hh:mm:ss) ........................
0003658

Post -Development 050 - Year Page 8
Subbasin : UNDISTURBED-BASIN-SUB-01A
6.2
6
5.8
F, 6
5.4
6.2
5
48
4.6
4.4
4.2
4
3.8
3.6
E 3.4
3.2
3
28
ry 2.6
2.4
22
2
1.8
1.6
1.4
1.2
1
08
0.6
0.4
02
75
70
BF,
60
55
50
45
40
35
ry
30
25
20
15
10
F,
Rai nfal I I nte n s ity G rap h
0 1 2 3 4 41 6 7 a 9 in 11 12 13 14 1 F, 16 17 18 19 20 21 22 23
Time (hrs)
Ru n off Hyd ro g raph
01234567891011121314151617181920212223
Time (hrs)

Post -Development 050 - Year
Subbasin : UNDISTURBED-BASIN-SUB-02
Page 9
Input Data
Area(ac) ........................................................................ 13.14
Peak Rate Factor ........................................................... 484.00
Weighted Curve Number ............................................... 70.54
Rain Gage I D ................................................................. Rain Gage-001
Composite Curve Number
Area
Soil Curve
Soil/Surface Description
(acres)
Group Number
Pasture, grassland, or range, Good
3.13
B 61.00
9.65
74.00
0.37
61.00
Composite Area & Weighted CN
13.15
70.54
Time of Concentration
Sheet Flow Computations
Manning's Roughness:
Flow Length (ft):
Slope (%):
2 yr, 24 hr Rainfall (in)
Velocity (fUsec) :
Computed Flow Time (min):
Total TOC (min) .................. 31.80
Subbasin Runoff Results
Subarea
Subarea
Subarea
A
B
C
.4
0.00
0.00
100
0.00
0.00
.67
0.00
0.00
3.50
0.00
0.00
0.05
0.00
0.00
31.80
0.00
0.00
Total Rainfall (in) ............................................................
6.90
Total Runoff (in) .............................................................
3.59
Peak Runoff (cfs) ...........................................................
30.95
Weighted Curve Number ...............................................
70.54
Time of Concentration (days hh:mm:ss) ........................
00031 48

Post -Development 050 - Year Page 10
Subbasin : UNDISTURBED-BASIN-SUB-02
6.2
6
5.8
F, 6
5.4
6.2
5
48
4.6
4.4
4.2
4
3.8
3.6
E 3.4
3.2
3
28
ry 2.6
2.4
22
2
1.8
1.6
1.4
1.2
1
08
0.6
0.4
02
34
32
30
28
26
24
22
20
18
16
ry
14
12
in
8
6
4
2
Rai nfal I I nte n s ity G rap h
0 1 2 3 4 41 6 7 a 9 in 11 12 13 14 1 F, 16 17 18 19 20 21 22 23
Time (hrs)
Ru n off Hyd ro g raph
01234567891011121314151617181920212223
Time (hrs)

Post -Development 050 - Year Page 11
Channel Input
SIN Element Length Inlet Inlet
Outlet Outlet Total Average Shape
Height Width Manning's Entrance Exit/Bend Additional Initial Flap
ID Invert Invert
Invert Invert Drop
Slope
Roughness Losses Losses Losses Flow Gate
Elevation Offset Elevation Offset
(ft) (ft) (ft)
(ft) (ft) (ft)
(%)
(ft) (ft) (cfs)
1 Link-02 50.00 555.00 0.00
554.90 1.60 0.10
0.2000 Rectangular
2.000 5.000 0.0010 0.5000 0.5000 0.0000 0.00 No

Post -Development 050 - Year Page 12
Channel Results
SN Element Peak Time of Design Flow Peak Flow/ Peak Flow Travel Peak Flow Peak Flow Total Time Froucle Reported
ID Flow Peak Flow Capacity Design Flow Velocity Time Depth Depth/ Surcharged NumberConclition
Occurrence Ratio Total Depth
Ratio
(cfs) (days hh:mm) (cfs) (fUsec) (min) (ft) (min)
1 Link-02 183.77 0 1230 712.92 0.26 26.43 0.03 1.39 0.70 0.00

Post -Development 050 - Year Page 13
Pipe Input
SIN Element Length Inlet Inlet Outlet Outlet Total Average Pipe Pipe Pipe Manning's Entrance Exit/Bend Additional Initial Flap
ID Invert Invert Invert Invert Drop Slope Shape Diameteror Width Roughness Losses Losses Losses Flow Gate
Elevation Offset Elevation Offset Height
(ft) (ft) (ft) (ft) (ft) (ft) (%) (in) (in) (cfs)
1 Outlet-Pipe-03 65.00 559.00 0.00 555.00 0.00 4.00 6.1500 CIRCULAR 42.000 42.000 0.0130 0.5000 0.5000 0.0000 0.00 No

Post -Development 050 - Year Page 14
No. of
Barrels

Post -Development 050 - Year Page 15
Pipe Results
SN Element Peak Time of Design Flow Peak Flow/ Peak Flow Travel Peak Flow Peak Flow Total Time Froucle Reported
ID Flow Peak Flow Capacity Design Flow Velocity Time Depth Depth/ Surcharged NumberConclition
Occurrence Ratio Total Depth
Ratio
(cfs) (days hh:mm) (cfs) (fUsec) (min) (ft) (min)
1 Outlet-Pipe-03 137.24 0 1209 249.58 0.55 14.26 0.08 3.50 1.00 38.00 SURCHARGED

Post -Development 050 - Year Page 16
Storage Nodes
Storage Node : Pond-03
Input Data
Invert Elevation (ft) ....................................................................
559.00
Max (Rim) Elevation (ft) ............................................................
571.50
Max (Rim) Offset (ft) .................................................................
12.50
Initial Water Elevation (ft) ..........................................................
565.00
Initial Water Depth (ft) ...............................................................
6.00
Poncled Area (ft2) .......................................................................
0.00
Evaporation Loss .......................................................................
0.00
OutflowWeirs
SIN Element
Weir Flap
Crest
Crest
Length
WeirTotal Discharge
ID
Type Gate
Elevation
Offset
Height Coefficient
(ft)
(ft)
(ft)
(ft)
1 Spillway-03
Trapezoidal No
571.00
12.00
50.00
0.50 3.33
2 Weir-03A
Rectangular No
566.80
7.80
5.00
1.20 3.33
Outflow Orifices
SIN 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-03 Bottom
Rectangular No
60.00
60.00
568.00 0.63
2 WQ-Orifice-03 Side
CIRCULAR No
5.00
565.00 0.61
Output Summary Results
Peak Inflow (cfs) ........................................................................
234.58
Peak Lateral Inflow (cfs) ............................................................
234.58
Peak Outflow (cfs) .....................................................................
137.79
Peak Exfiftration Flow Rate (cfm) ..............................................
0.00
Max HGL Elevation Attained (ft) ................................................
569.75
Max HGL Depth Attained (ft) .....................................................
10.75
Average HGL Elevation Attained (ft) .........................................
566.48
Average HGL Depth Attained (ft) ..............................................
7.48
Time of Max HGL Occurrence (days hh:mm) ...........................
0 1218
Total Exfiltration Volume (1 000-ft3) ...........................................
0.000
Total Flooded Volume (ac-in) ....................................................
0
Total Time Flooded (min) ..........................................................
0
Total Retention Time (sec) ........................................................
0.00

Post -Development 100 - Year Page 1
Project Description
File Name .................................................... 27842.0002 - Post Development.SPF
Project Options
Flow Units ...................................................
CIFS
Elevation Type ............................................
Elevation
Hydrology Method .......................................
SCS TR-55
Time of Concentration (TOC) Method ........
SCS TR-55
Link Routing Method ...................................
Hydrodynamic
Enable Overflow Poncling at Nodes ............
YES
Skip Steady State Analysis Time Periods
NO
Analysis Options
Start Analysis On ........................................
Dec 03, 2020
000000
End Analysis On ..........................................
Dec 04, 2020
000000
Start Reporting On ......................................
Dec 03, 2020
000000
Antecedent Dry Days ..................................
0
days
Runoff (Dry Weather) Time Step ................
001 0000
days hh:mm:ss
Runoff (Wet Weather) Time Step ...............
0000500
days hh:mm:ss
Reporting Time Step ...................................
0000500
days hh:mm:ss
Routing Time Step ......................................
1
seconds
Number of Elements
Qty
RainGages .................................................
1
Subbasins....................................................
3
Nodes...........................................................
5
Junctions --------------------------------------------
2
Outfalls -----------------------------------------------
2
Flow Diversions ----------------------------------
0
Inlets---------------------------------------------------
0
Storage Nodes -----------------------------------
1
Links.............................................................
6
Channels --------------------------------------------
1
Pipes--------------------------------------------------
1
Pumps------------------------------------------------
0
Orifices-----------------------------------------------
2
Weirs--------------------------------------------------
2
Outlets------------------------------------------------
0
Pollutants....................................................
0
LandUses ...................................................
0
Rainfall Details
SIN Rain Gage Data Data Source Rainfall Rain State County Return Rainfall Rainfall
ID Source ID Type Units Period Depth Distribution
(years) (inches)
1 Time Series TS-100 Intensity inches NorthCarolina Union 100 7.50 SCS Type III 24-hr

Post -Development 100 - 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 POST-DEVELOPMENT-BASIN-SUB-01B
45.50
484.00
85.92
7.50
5.84
265.63 260.52
0 000500
2 UNDISTURBED-BASIN-SUB-01A
23.79
484.00
79.00
7.50
5.04
119.98 73.04
0 003657
3 UNDISTURBED-BASIN-SUB-02
13.14
484.00
70.54
7.50
4.10
53.83 35.31
0 003148

Post -Development 100 - Year Page 3
Node Summary
SIN Element Element
Invert Ground/Rim
Initial Surcharge Poncled Peak Max HGL
Max
Min
Time of
Total Total Time
ID
Type
Elevation
(Max)
Water
Elevation
Area I nflow
Elevation Surcharge Freeboard
Peak Flooded
Flooded
Elevation Elevation
Attained
Depth
Attained
Flooding
Volume
Attained
Occurrence
(ft)
(ft)
(ft)
(ft)
(ft') (cfs)
(ft)
(ft)
(ft)
(days hh:mm)
(ac-in)
(min)
1 CS
Junction
555.00
570.20
558.00
999.00
0.00 190.20
565.54
0.00
4.66
0 0000
0.00
0.00
2 Jun-03
Junction
559.00
570.20
559.00
999.00
0.00 138.14
568.81
0.00
1.39
0 0000
0.00
0.00
3 Out-01
Outfall
553.30
190.17
553.30
4 Out-02
Outfall
560.00
34.89
560.00
5 Pond-03 Storage Node
559.00
571.50
565.00
0.00 258.69
570.13
0.00
0.00

0
�2
E
0
0
0-
o
0
w 0 D
Ir 0 U)
w , 0 0
E w 0 0
0
0
0 0 0
0 � 0 �
w m —0
1 Ir
m
e� 0 0
0
3:
0
0
>
3:.o 0
0 0 4,� 0
0 0
0
0 m 0
m 0 t 0 M 0 0
W
0 0 0
�2 ',� 12 m
0(
�2 0
00
00
0
0 0 0 0
0 0 0 0
W 0000
z N 0 0
E 0
m
. C,
w
00
00
m 0 00
> 00
E000000
om0000
0 � m m 0 m
> 000000
w 000000
w
Z4,fg E000000
Ew000000
>
000000
000000
w
0 0
tt� 0 0
00
00
C? C? C?
U)
0
U)
0 0 0
m
m C? C? C? C?
E C? . . . .
2 'o U) 'o 'o 'o 'o
C? C?
m w m
C? I C? <
N E In
0 C?
E wE
U) w 0 0 ?: U') ?:
U)
r

Post -Development 100 - Year
Subbasin Hydrology
Page 5
Subbasin : POST-DEVELOPMENT-BASIN-SUB-01B
Input Data
Area(ac) ........................................................................
45.50
Peak Rate Factor ...........................................................
484.00
Weighted Curve Number ...............................................
85.92
Rain Gage I D .................................................................
Rain Gage-001
Composite Curve Number
Area
Soil
Curve
Sol/Surface Description
(acres)
Group
Number
Paved parking & roofs
13.67
B
98.00
� 75% grass cover, Good
14.69
B
61.00
Future -Paved parking & roofs
16.63
B
98.00
Composite Area & Weighted CN
44.99
85.92
Time of Concentration
TOC Method SCSTR-55
Sheet Flow Equation :
Tc = (0.007 * ((n * Lf)^0.8)) / ((PAO.5) * (SfAO.4))
Where
Tc =
Time of Concentration (hr)
n =
Manning's roughness
Lf =Flow
Length (ft)
P =
2 yr, 24 hr Rainfall (inches)
Sf =Slope
(fVft)
Shallow Concentrated Flow Equation
V =
16.1345 (SfAO.5) (unpaved surface)
V =
20.3282 (SfAO.5) (paved surface)
V =
15.0 (SfAO.5) (grassed waterway surface)
V =
10.0 (SfAO.5) (nearly bare & untilled surface)
V =
9 0 (SfAO.5) (cultivated straight rows surface)
V =
7.0 (SfAO.5) (short grass pasture surface)
V =
5.0 (SfAO.5) (woodland surface)
V =
2.5 (SfAO.5) (forest w/heavy litter surface)
Tc
= (Lf V) / (3600 sec/hr)
Where
Tc Time of Concentration (hr)
Lf Flow Length (ft)
V Velocity (fVsec)
Sf Slope (fVft)
Channel Flow Equation:
* = (1.49 - (RA(2/3)) * (SfAO.5)) / n
* =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 (fVsec)
Sf =
Slope (ft/ft)
n =
Manning's roughness
User -Defined TOC override (minutes): 5.00
Subbasin Runoff Results
Total Rainfall (in) ............................................................ 7.50
Total Runoff (in) ............................................................. 5.84
Peak Runoff (cfs) ........................................................... 260.52
Weighted Curve Number ............................................... 85.92
Time of Concentration (days hh:mm:ss) ........................ 0000500

Post -Development 100 - Year Page 6
Subbasin : POST-DEVELOPMENT-BASIN-SUB-01B
6.5
6
5.5
5
4.5
4
3.5
'E 3
2.5
2
1.5
1
0.5
270
260
250
240
230
220
210
200
190
180
170
160
150
140
130
r 1 120
y
110
100
90
00
70
60
Flo
40
30
20
10
Rainfall Intensity Graph
0 1 2 3 4 41 6 7 a 9 in 11 12 13 14 1 F, 16 17 18 19 20 21 22 23
Time (hrs)
Ru n off Hyd ro g raph
01234567891011121314151617181920212223
Time (hrs)

Post -Development 100 - Year
Subbasin : UNDISTURBED-BASIN-SUB-01A
Page 7
Input Data
Area(ac) ........................................................................ 23.79
Peak Rate Factor ........................................................... 484.00
Weighted Curve Number ............................................... 79.00
Rain Gage I D ................................................................. Rain Gage-001
Composite Curve Number
Area
Soil Curve
Soil/Surface Description
(acres)
Group Number
Woods, Fair
23.79
D 79.00
Composite Area & Weighted CN
23.79
79.00
Time of Concentration
Subarea
Subarea
Subarea
Sheet Flow Computations
A
B
C
Manning's Roughness:
.4
0.00
0.00
Flow Length (ft):
100
0.00
0.00
Slope (%):
9.5
0.00
0.00
2 yr, 24 hr Rainfall (in)
3.50
0.00
0.00
Velocity (fUsec) :
0.15
0.00
0.00
Computed Flow Time (min)
11.01
0.00
0.00
Subarea
Subarea
Subarea
Shallow Concentrated Flow Computations
A
B
C
Flow Length (ft):
1370
0.00
0.00
Slope (%):
.3
0.00
0.00
Surface Type
Unpaved
Unpaved
Unpaved
Velocity (fUsec)
0.88
0.00
0.00
Computed Flow Time (min):
25.95
0.00
0.00
Total TOC (min) .................. 36.96
Subbasin Runoff Results
Total Rainfall (in) ............................................................
7.50
Total Runoff (in) .............................................................
5.04
Peak Runoff (cfs) ...........................................................
73.04
Weighted Curve Number ...............................................
79.00
Time of Concentration (days hh:mm:ss) ........................
0003658

Post -Development 100 - Year Page 8
Subbasin : UNDISTURBED-BASIN-SUB-01A
7
6
4
4
3.5
3
ry
2.5
2
1.5
0.5
00
7F,
70
65
60
F; F,
50
45
40
o
ry 3F,
30
25
20
15
10
5
Rai nfal I I nte n s ity G rap h
0 1 2 3 4 41 6 7 a 9 in 11 12 13 14 1 F, 16 17 18 19 20 21 22 23
Time (hrs)
Ru n off Hyd ro g raph
01234567891011121314151617181920212223
Time (hrs)

Post -Development 100 - Year
Subbasin : UNDISTURBED-BASIN-SUB-02
Page 9
Input Data
Area(ac) ........................................................................ 13.14
Peak Rate Factor ........................................................... 484.00
Weighted Curve Number ............................................... 70.54
Rain Gage I D ................................................................. Rain Gage-001
Composite Curve Number
Area
Soil Curve
Soil/Surface Description
(acres)
Group Number
Pasture, grassland, or range, Good
3.13
B 61.00
9.65
74.00
0.37
61.00
Composite Area & Weighted CN
13.15
70.54
Time of Concentration
Sheet Flow Computations
Manning's Roughness:
Flow Length (ft):
Slope (%):
2 yr, 24 hr Rainfall (in)
Velocity (fUsec) :
Computed Flow Time (min):
Total TOC (min) .................. 31.80
Subbasin Runoff Results
Subarea
Subarea
Subarea
A
B
C
.4
0.00
0.00
100
0.00
0.00
.67
0.00
0.00
3.50
0.00
0.00
0.05
0.00
0.00
31.80
0.00
0.00
Total Rainfall (in) ............................................................
7.50
Total Runoff (in) .............................................................
4.10
Peak Runoff (cfs) ...........................................................
35.31
Weighted Curve Number ...............................................
70.54
Time of Concentration (days hh:mm:ss) ........................
00031 48

Post -Development 100 - Year Page 10
Subbasin : UNDISTURBED-BASIN-SUB-02
7
6
4
4
3.5
3
ry
2.5
2
1.5
0.5
30
36
34
32
30
28
26
24
22
20
18
16
14
12
10
8
6
4
2
Rai nfal I I nte n s ity G rap h
0 1 2 3 4 41 6 7 a 9 in 11 12 13 14 1 F, 16 17 18 19 20 21 22 23
Time (hrs)
Ru n off Hyd ro g raph
01234567891011121314151617181920212223
Time (hrs)

Post -Development 100 - Year Page 11
Channel Input
SIN Element Length Inlet Inlet
Outlet Outlet Total Average Shape
Height Width Manning's Entrance Exit/Bend Additional Initial Flap
ID Invert Invert
Invert Invert Drop
Slope
Roughness Losses Losses Losses Flow Gate
Elevation Offset Elevation Offset
(ft) (ft) (ft)
(ft) (ft) (ft)
(%)
(ft) (ft) (cfs)
1 Link-02 50.00 555.00 0.00
554.90 1.60 0.10
0.2000 Rectangular
2.000 5.000 0.0010 0.5000 0.5000 0.0000 0.00 No

Post -Development 100 - Year Page 12
Channel Results
SN Element Peak Time of Design Flow Peak Flow/ Peak Flow Travel Peak Flow Peak Flow Total Time Froucle Reported
ID Flow Peak Flow Capacity Design Flow Velocity Time Depth Depth/ Surcharged NumberConclition
Occurrence Ratio Total Depth
Ratio
(cfs) (days hh:mm) (cfs) (fUsec) (min) (ft) (min)
1 Link-02 190.17 0 1230 712.92 0.27 27.17 0.03 1.40 0.70 0.00

Post -Development 100 - Year Page 13
Pipe Input
SIN Element Length Inlet Inlet Outlet Outlet Total Average Pipe Pipe Pipe Manning's Entrance Exit/Bend Additional Initial Flap
ID Invert Invert Invert Invert Drop Slope Shape Diameteror Width Roughness Losses Losses Losses Flow Gate
Elevation Offset Elevation Offset Height
(ft) (ft) (ft) (ft) (ft) (ft) (%) (in) (in) (cfs)
1 Outlet-Pipe-03 65.00 559.00 0.00 555.00 0.00 4.00 6.1500 CIRCULAR 42.000 42.000 0.0130 0.5000 0.5000 0.0000 0.00 No

Post -Development 100 - Year Page 14
No. of
Barrels

Post -Development 100 - Year Page 15
Pipe Results
SN Element Peak Time of Design Flow Peak Flow/ Peak Flow Travel Peak Flow Peak Flow Total Time Froucle Reported
ID Flow Peak Flow Capacity Design Flow Velocity Time Depth Depth/ Surcharged NumberConclition
Occurrence Ratio Total Depth
Ratio
(cfs) (days hh:mm) (cfs) (fUsec) (min) (ft) (min)
1 Outlet-Pipe-03 137.50 0 1207 249.58 0.55 14.29 0.08 3.50 1.00 47.00 SURCHARGED

Post -Development 100 - Year Page 16
Storage Nodes
Storage Node : Pond-03
Input Data
Invert Elevation (ft) ....................................................................
559.00
Max (Rim) Elevation (ft) ............................................................
571.50
Max (Rim) Offset (ft) .................................................................
12.50
Initial Water Elevation (ft) ..........................................................
565.00
Initial Water Depth (ft) ...............................................................
6.00
Poncled Area (ft2) .......................................................................
0.00
Evaporation Loss .......................................................................
0.00
OutflowWeirs
SIN Element
Weir Flap
Crest
Crest
Length
WeirTotal Discharge
ID
Type Gate
Elevation
Offset
Height Coefficient
(ft)
(ft)
(ft)
(ft)
1 Spillway-03
Trapezoidal No
571.00
12.00
50.00
0.50 3.33
2 Weir-03A
Rectangular No
566.80
7.80
5.00
1.20 3.33
Outflow Orifices
SIN 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-03 Bottom
Rectangular No
60.00
60.00
568.00 0.63
2 WQ-Orifice-03 Side
CIRCULAR No
5.00
565.00 0.61
Output Summary Results
Peak Inflow (cfs) ........................................................................
258.69
Peak Lateral Inflow (cfs) ............................................................
258.69
Peak Outflow (cfs) .....................................................................
138.14
Peak Exfiftration Flow Rate (cfm) ..............................................
0.00
Max HGL Elevation Attained (ft) ................................................
570.13
Max HGL Depth Attained (ft) .....................................................
11.13
Average HGL Elevation Attained (ft) .........................................
566.54
Average HGL Depth Attained (ft) ..............................................
7.54
Time of Max HGL Occurrence (days hh:mm) ...........................
0 1220
Total Exfiltration Volume (1 000-ft3) ...........................................
0.000
Total Flooded Volume (ac-in) ....................................................
0
Total Time Flooded (min) ..........................................................
0
Total Retention Time (sec) ........................................................
0.00

25-YR
CAPACITY

HEC-22
Energy Grade Line Computations
Struct.
ID
Q
(cfs)
I
EGLo
(ft)
I
HGLo
(ft)
I
Total Pipe
Loss
(ft)
EGU
(ft)
HGU
(ft)
Ea
(ft)
EGLa
(ft)
SU face Elev.
(ft)
2 569.31
569.31
569.92
0.37 572.75 571.20 7.5 573.37 580.59
1
141.9
572.38
570.86
3
133.1
573.80
572.71
0.70
574.50
573.41
8.6
575.25
580.87
4
78.2
575.49
574.89
0.18
575.67
575.06
9.2
576.17
580.61
5
77.9
576.41
575.81
0.08
576.49
575.89
9.9
576.99
580.63
6
78.2
577.23
576.63
0.29
577.52
576.92
10.1
577.71
579.77
7
64.3
577.87
577.46
0.32
578.19
577.78,
10.0
578.38,
580.96
8
64.3
578.54
578.14
0.06
578.60
578.19
10.3
578.84
581.33
20
8.4
578.98
578.63
0.23
579.21
578.86
9.3
579.39
581.33
21
7.9
579.51
579.20
0.14
579.66
579.34
9.5
579.80
581.61
22
5.1
579.86
579.72
0.24
580.09
579.96
2.5
580.13
582.44
23
4.2
580.16
580.07
0.16
580.32
580.23
1.8
580.38
583.28
24
2.0
580.38
580.36
0.01
580.40
580.38,
1.4
580.41,
583.42
25
1.9
579.81
579.79
0.01
579.82
579.80
9.3
579.83
581.76
9
55.8
578.96
578.66
0.16
579.12
578.82
6.7
579.23
584.35
10
41.1
579.34
579.06
581.83
578.61
4.4
581.83
593.38
11
40.1
581.93
581.66
585.07
581.89
4.4
585.07
597.70
12
40.0
585.27
584.77
0.85
586.12
585.62
3.8
586.30
596.59
13
36.9
586.47
586.05
588.17
586.37,
3.3
588.17,
595.03
14
31.4
588.29
587.98
0.23
588.52
588.21
3.2
589.08
595.95
15
16.0
589.15
588.96
591.22
590.29
1.9
591.22
600.79
16
15.9
591.32
591.08
592.03
591.08
2.0
592.03
602.46
17
6.0
594.39
593.12
599.47
598.20
1.8
599.47
606.49
18
4.9
599.48
599.44
600.68
600.00
1.3
600.68
609.27
19
1.6
600.69
600.67
601.41
600.80,
0.9
601.41,
609.26,
38
8.2
592.09
591.94
592.76
592.35
1.8
593.09
596.81
39
7.0
593.12
593.03
593.12
592.75
1.6
593.12
596.81
14
13.8
589.20
588.90
0.14
589.34
589.03
3.2
589.49
596.11
34
9.1
589.54
589.41
0.25
589.79
589.66
2.1
589.90
595.08
49
4.8
590.00
589.76
0.73
590.73
590.49
1.9
590.84
593.03
33
1.8
590.85
590.82
591.24
590.99,
0.8
591.26,
595.11
35
4.0
591.24
589.99
593.79
592.54
1.7
593.79
596.73
36
2.9
593.83
593.74
597.72
596.68
1.5
597.72
600.70
50
3.1
588.20
588.12
588.39
588.00
1.0
588.39
595.03
53
1.8
586.31
586.29
0.01
586.32
586.30
3.5
586.35
596.60
9
13.9
579.25
579.19
0.02
579.27
579.21
6.0
579.31
585.71
26
10.7
579.32
579.28
0.04
579.36
579.32,
4.5
579.37,
580.63
28
4.6
579.39
579.35
0.05
579.43
579.40
3.8
579.44
581.28
29
3.2
579.46
579.41
0.10
579.56
579.51
3.3
579.59
582.90
30
1.6
579.60
579.58
0.03
579.63
579.62
2.6
579.63
581.49
31
1.8
579.38
579.36
587.64
586.68
1.2
587.64
593.45
51
10.2
577.77
577.61
0.14
577.92
577.75
4.4
577.97
579.46
52
7.1
578.01
577.93
0.17
578.18
578.10,
3.7
578.22,
581.50
48
3.3
577.73
577.68
0.03
577.76
577.70
6.0
577.78
579.77
43
6.4
573.45
573.24
0.41
573.86
573.65
3.4
573.93
577.47
44
4.5
573.97
573.87
0.27
574.24
574.14
2.2
574.28
578.97
45
3.3
574.33
574.21
0.40
574.72
574.61
1.2
574.77
580.47
46
2.5
574.80
574.73
575.96
575.58
1.0
576.02
579.58
47
0.8
576.02
576.01
577.24,
577.05,
0.5
57
581.33
40
3.4
573.39
573.33
0.10
573.491
573.431
6.4
573.52
581.89
41
1 2.7
573.551
573.47
0.271
573.821
573.741
.2
573.89
584.30
142
1 1.31
573.891
573.881
0.051
573.951
573.931
4.0
573.97
586.29
PiTHOMAS - HUTTON Z.,�27842�27842.0002�Engineering�Calculations and Reports�Ston,n Water�HEC-22�2021-06-01�Copy of HEC-22 Reporting

HEC-22
Storm Drain Computations
Structure ID
Length
(ft)
Drainage
Area
I (a c)
Runoff
Coeff"C"
Tc
(min)
I
Rain "I"
(in/hr)
Runoff
1. Q1.
I (cfs)
Known Q
(cfs)
I
Total Q
(cfs)
Pipe Dia.
(i n)
I
Velocity
Design
(ft/s)
Invert Elevation
I
Slope
=Fr . :.=
U/S I D/S
2 1 74, 0.01, 0.55, 5. 7.32 75.5 . 141.91 54 10.0 565.87, 565.501 0.50%
3_ 12 1 1521 0.041 0.551 51 738 66.81 55.01 133.11 54, 10.01 566.641 565.871 0.. q5O %
"i" -
1 +1 66.81 1 78.21 481 8.91 566.941 566.641 0
13 1 601 0.091 0.551 5 0.509
r4 7.4 . 500%.
PiTHOMAS - HUTTON Z.,�27842�27842.0002�Engineering�Calculations and Reports�Ston,n Water�HEC-22�2021-06-01�Copy of HEC-22 Reporting

4 IN/HR
INLET
SPREAD

CL)
U u
LLJ
U
4-
CL)
0. u
;:- P
-tr
rn
r,
-i
LD
-i
00
m
m
-i
0
Ln
m
-4
0
-4
m
w
0
.
Ln
.
fli
.
-4
.
0
.
-!
"Zk
N
N
N
a�
N
q
q
-!
"Zk
"
In
-i
-i
00000000
000000000
m 0 cr -u
00
rn
a,
rn
Iq
,I:
,I:
a�
'ZI:
Iq
q
a
6 cs
2
cs
o
-4
o
o
-4
o
o
o
o
_4
ci
6
6
6
�4
ci
ci
ci
�4
�4
ci
ci
ci
ci
�4
ci
'66666
w
u -u
.2
b.0
.
.
.
.
.
.
.
.
.
.
.
.
.
.
N
N
N
.
.
.
.
.
u
.
.
.
.
.
.
.
.
.
.
.
.
.
.
Lr)
Lr)
Lri
Lri
Lri
Lri
m
m
m
m
m
m
m
r�
m
m
m
m
m
m
m
m
m
rn
m
m
r,
u zr-
0 -
I
=
cq
OR
OR
OR
OR
OR
OR
OR
OR
OR
cq
cq
cq
cq
cq
cq
OR
Iq
Iq
Iq
Iq
Iq
Iq
Iq
LO
LO
LO
LO
LO
Iq
Iq
Iq
Iq
Iq
Iq
Iq
Iq
Iq
Iq
cq
cq
cq
cq
cq
cq
cq
cq
cq
cq
cq
cq
cq
cq
cq
cq
cq
LQ
LQ
LQ
LQ
LQ
LQ
LQ
LQ
9
LQ
LQ
LQ
LQ
LQ
LQ
LQ
LQ
LQ
LQ
9
.
.
.
.
.
.
.
.
m
.
rn
.
rn
.
rn
.
rn
.
rn
.
m
.
Ln
m
Ln
m
Ln
m
Ln
m
Ln
m
Ln
m
Ln
m
Ln
m
-4
r,
Ln
m
Ln
m
L6
m
Ln
m
Ln
m
Ln
m
Ln
m
Ln
m
ui
m
Ln
m
Ln
m
Ln
m
-i
r,
r
r
r
r
r
r
r
r
r
r
r
r
r
r
r
r
r
r
r
r
r
r
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
- 0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
F=
Q)
w
w
w
w
w
w
w
w
w
w
w
wwww
Q)
-
-
-
-
-
-
-
I.E
-
I.E
-
I.E
-
-
-
-
I.E
-
I.E
-
-
IS
E
E
E
E
E
E
E
E
E
E
E
E
E
E
E
E
E
E
E
E
E
E
o
o
o
o
o
o
o
o
o
o
o
o
o
o
o
o
o
o
o
o
o
o
rl
Ui
cq
cq
"
"i
Iq
-i
LQ
cq
Ui
a�
Iq
r-�
Ui
r-�
"Zt
"Zt
-i
a�
9
In
In
a�
-i
9
In
Ui
9
"Zt
cq
Iq
C5
0'
-4
0
0
-4
0
0
-4
0
0
0
ci
0
0
0
0
00
'T
LO
'T
0
0
r-:
0
0
m
0
LO
LO
0
0
m
-4
Ln
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
N
N
Ln
In
In
"Zk
N
"Zk
In
N
N
In
N
N
N
N
N
N
N
N
N
N
N
N
N
N
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
C6
0
0
0
0
0
cs
0
0
0
0
w F�
rn
a�
a�
m
ko
T
T
m
;T
ko
o
ko
F,
T
m
w
w
ko
o
o
o
ko
F,
m
m
U
m
F,
o
-i
F,
F,
o
-i
w
cu
o o
o
o
o
In
m
0
0
0
0
0
0
0
0
0
0
0
-u
f
co
cn:��
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
b.2
Ln —
I
rn m
m
m
m
m
r"4
r4
r4
r4
r4
rT
In
rn
rn
In
rn
0
-05
0 0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
010
0
010
0
0
0
0
0
0
b
10
0 0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1-1
1-1
m
m
0
-,
"
Ln
Ln
Ln
1-1
1-1
1-1
1-1
0
0
1-1
0
0 0
0
0
0
4-4-4-4-4,�,�,�,�,�,�00000000,v000000000,v,vo,v
0 Ln
M
c
0
3: 0 cr -u
c
�d
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
u
cq
rl�
In
C�
C�
Ui
In
Iq
"Zt
,I:
C�
"Zt
Iq
I?
Iq
rl�
"Zt
a�
Iq
OR
Iq
Iq
a�
q
LQ
,I:
a�
rn
Iq
a�
rl�
q
li
LQ
LQ
Ln
-4
00
0
0
r4
0
0
-4
0
0
-4
0
0
0
0
-4
0
0
0
0
0
0
-4
0
0
-4
"
-4
0
0
0
0
-4
-4
-4
0
0
0
0
—u
u
p
m
U,
LO
Ln
T
m
0
-4
-4
-4
1-4
CA
1-4
-4
1-1
1-1
co
r-I
LO
a

CL)
U u
LLJ
U
4-
CL)
E
m
0. u
;:- P
co
co
'T
-ZT
0
Ln
m
0
0
0
co
-
-
-
-
-
-
-
-
-
-
-
"
-i
a�
1p
q
a�
cq
-i
1p
r-�
0
0
0
0
"
0
-4
0
0
0
-4
0
u
a
tw
.
.
.
.
.
r1l
-tr
-tr
-tr
-tr
tw
u w
0. W Z7-
0
-
-
-
-
-
-
-
-
-
-
tw
ui
ui
ui
ui
q
q
q
Ln
Ln
Lnn
Ln
Ln
-4
1-1
oo
Ln
rn
r
m
m
r,
r,
rn
u w
0.
o
'W
1p
LP
LP
LP
1p
cq
1p
cq
q
cq
cq
m-a
W
ui
ui
ui
ui
q
cq
q
cq
q
cq
cq
Ln
m
Ln
m
Ln
m
Ln
m
-4
r,
m
"
-4
r,
m
r4
oo
r4
m
"
m
"
ui
m
w
0.
0
0
0
0
0
0
0
0
W
-0
Q)
Q)
-0
E
E
E
E
E
E
E
0
0
0
0
0
u
UO
0
u
0
a
"z,:
q
Lq
"z,:
m
-4
rn
-4
LO
r,
0
Ln
0
-4
r-I
Ln
Ln
r4
r4
r4
o
r4
o
r4
r4
r4
f-I
000000000000
'R
q
ai
cq
'R
C7
76
o
o
o
_4
"
o
_4
o
o
o
_4
0-1
0
.2 —u
0 .2 -Zr
0
0
0
0
0
0
0
0
0
0
Ln
.
q
.
q
.
q
.
q
r4
q
rn
en
r4
q
rn
en
r4
q
r4
q
r4
q
r4
q
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
m
0
0
1-1
0
0
0
0
C�
q
q
q
q
q
q
q
C
.
0
.
0
0
0
0
0
0 Ln
M
c
0
3: 0 cr —u
u
0�
Li
q
le
cq
le
a�
0000-401-40001-40
—u
u
m
Ln
m
Ln
"
1_1
I Ln
I Ln
I Ln
a

STORMWATER MANAGEMENT REPORT
CRESSWIND WESLEY CHAPEL - PHASE 02
APPENDix F
WATER QUALITY
CALCULATIONS
A THOMAS & HUTTON

Water Quality Calculations
Cresswind - Wesley Chapel
Proiect No. 27842.002
WET POND 03
Project/Drainage Area: 45.46 Acres Required Water Quality Volume: 107,241 Cubic Feet
Impervious Area: 3030 Acres (Project Area (Acres) X 43,560 SF X 1"/12 - Required Cubic Feet Volume)
Percent Impervious Runoff Coeifficient: R-05,0.9 (1) - 1 0.65
jined Collection of First I" of Rainfall from the Project Site and Release over a Minimum 48 Hour (Maximum 120 Hours) in Cubic Feet Per Second)
48-Hour Release Rate: CFS Required Orifice Si— Drawdown Time (Hours):
Quality Elevation
Elev.
"e,
Area
Storage
ft)
( ff')
(sf)
(cu. ft)
65.00
5 56500
48,889.00
0.00
571.00
57� 00
72,687.00
364,728.00
,ZWater
Elevation
e'ahrm
Pond Depth
Storage
ff')
fft)
fft
(cu. ft)
565.00
56500
0.00
0.00
566.76
1.76
107,241.09
571.00
6.60
364,728.00
Average Depth Calculation
Vpp Designed @ Elevation
71565.0000
65
190,429.00
SA Designed @ Elevation
39,712.00
Area of wet pond at the bottom ofthe
shelf
36,949.00
Dmax over shelf
0.50
Perimeter of Permanent Pool
1,055.00
Width of submerged part of shelf
3.00
Volumeoverthesh Ifonly
791.25
V;-- —
v .g�a,�
5.13
'W SA/DA Method
Drainage Area
45
-1111011-
Table value
61acres
1�� 8
Surface Area Required
1 33,267.99
Isquare feet
Q-CdA*sqrt(2gh)
Cd -
0.62
(Sharp Orifice
A -
0.136
sf
9-
32.174
ft/s,
h -
1.76
ft
Q-
0.637
cf,;
VPP-Vshelf
D., Abottomofshelf
v, TM,1 & p,r.,.,.t ­1 &01)
—u.. th. —1-1y (--) - — —
A ... f — .111. —1— .1h.
v—, � 0.5 ' DIPth— el---. ­ ' Widft.—­ ­
.h- =­r1tth,d, id,�thllhllfll
d t --t ­1
Wid--- dr, 'r— d"
= f - --rn=n- �1

Stage Storage Calculations
Cresswind - Wesley Chapel
Project No. 27842.0002
WET POND 03
FOREBAY01VOLUME
INC. VOL..AVG.
CUM. VOL. AVG. END
F�w
I!=
END (CU FT.)
(CU. FT.)
559
1,761
N/A
N/A
0
560
2,102
1
1,932
1,932
561
2,474
1
2,288
4,220
562
2,875
1
2,674
6,894
563
3,306
1
3,090
9,984
564
3,766
1
3,536
13,520
564.5
4,128
0.5
1,973
15,493
565
4,647
0.5
2,194
17,687
'MM'
qr
INC. VOL..AVG.
CUM. VOL. AVG. END
F�w
ffm
END (CU FT.)
(CU. FT.)
559
1,074
N/A
N/A
0
560
1,368
1.00
1,221
1,221
561
1,692
1.00
1,530
2,751
562
2,045
1.00
1,869
4,620
563
2,428
1.00
2,237
6,857
564
2,840
1.00
2,634
9,491
564.5
3,137
0.50
1,494
10,985
565
3,667
0.50
1,701
12,686
TOTAL FOREBAY VOLUME: I 30,3731CU. FT.
PERCENTAGE OF PERMANENT POOL VOLUME:j 15.951%
PERMANENT POOL VOLUME
CONTOUR AREA
CONTOUR ELEV
DEPTH (FT)
559
25710
N/A
N/A
0
560
27625
1
26,667
26,667
561
29,582
1
28,603
55,270
562
31,581
1
30,582
85,852
563
33,618
1
32,599
118,451
564
35,690
1
34,654
153,105
564.5
36,949
0.5
18,159
171,264
565
39,712
0.5
19,165
190,429
PERMANENT POOL VOLUME: I
190,4291CU.FT
TEMPORARY PONDING ZONE A&.
CONTOUR ELEV CONTOUR AREA DEPTH (FT) INC. VOL. AVG. CUM. VOL. AVG. END
(SF) END (CU. FT.) (CU. FT.)
565
48,889
N/A N/A
0
565.5
52,395
0.5 25,321
25,321
566
54,139
0.5 26,634
51,955
567
57,738
1 55,939
107,894
568
61,391
1 59,565
167,458
569
65,091
1 63,241
230,699
570
68,845
1 66,968
297,667
571
72,687
1 70,766
368,433
TEMPORARY PONDING ZONE VOLUME: I
368,4331CU. FT.

Cresswind Wesley Chapel - Phase 02 Job: J-27842.0002
KH Wesley Chapel, LLC Date: 2/18/21
Thomas & Hutton Engineering Co. Revised:
Anti -Flotation Design Considerations By: MSK
ANTI -FLOTATION DESIGN CONSIDERATIONS FOR:
Wet Pond 02 1
CONTROL STUCTURE ELEVATIONS
Top Structure Elevation: 570.20
Bottom Structure Elevation: 558.80
CONTROL STRUCTURE FLOTATION
Buoyant Force,
Calculate submerged volume:
Vs = (As x H,$)
Where:
Vs = Submerged volume (cf)
L,s = Length of control structure (ft) 6.00 ft
W,s = Width of Control structure (ft) 6.00 ft
A,s - Cross -sectional area of control structure (ft) 36.00 ft
H,s = Height of control structure (ft) 11.40 ft
Solve equation for Vs:
V, = (A,s x H,$) 410.40 cf
Calculate buoyant force:
Fb = V� X 7w.W,
Where:
Fb = buoyant force (lbf)
y,,,, = Specific weight of water 62.40 lbf/cf
Fb = 25,609 lbf
Z:\27842\27842.0002\Engineering\Calculations and Reports\Storm Water\Anti Flotation\27842.0002 - Wet Pond 03 - Anti Flotation
Design Calculations Pagel of3

Cresswind Wesley Chapel - Phase 02 Job: J-27842.0002
KH Wesley Chapel, LLC Date: 2/18/21
Thomas & Hutton Engineering Co. Revised:
Anti -Flotation Design Considerations By: MSK
Downward Force
Calculate Downward Force of Control Structure
Fdc� = (V.� - V�& - V.rj&�) x yconcrete
Where:
Wt,s =
Weight of control structure (lbs)
,y,on .. t, =
Specific weight of concrete
— 140.00 lbf/cf
A,s =
Cross -sectional area of control structure (ft)
— 36.00 ft
H,s =
Height of control structure (ft)
— 11.40 ft
T,s =
Wall thickness of control structure (ft)
— 0.50 ft
V,, =
Volume of control structure (cf)
— 125.40 cf
W,,i, =
Width of weir (ft)
— 5.00 ft
H,,i,
= Height of weir opening (ft)
— 1.20 ft
A,,i,
= Area of weir opening(ft)
— 6.00 sf
V,,,,
= Volume of weir
— 3.00 cf
DIAO,ifi,,
= Diameter of orifice opening (in)
— 5.00 in
AO,jfj,,
= Area of orifice opening (sf)
— 0.136 sf
VO,jfj,,
= Volume of orifice opening (sf)
— 0.068 cf
Fd,, = 17,126 lbf
Size Anti -Flotation Footing to Resist BoLlyant Force
Fd,s + Fdft > Fb
Fdft = (Lb X Wb x Db) X 7concrete
Where:
Fd,s =
downward force of control structure (Ibf) —
17126 Ibf
Fb =
buoyant force (Ibf) —
25609 Ibf
,y,on,r,, =
Specific weight of concrete —
77.60 Ibf/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 (Ibf) —
11174 Ibf
Z:\27842\27842.0002\Engineering\Calculations and Reports\Storm Water\Anti Flotation\27842.0002 - Wet Pond 03 - Anti Flotation
Design Calculations Page 2 of 3

Cresswind Wesley Chapel - Phase 02
KH Wesley Chapel, LLC
'Ibomas & Hutton Engineering Co.
Job: J-27842.0002
Date: 2/18/21
Revised:
Anti -Flotation Design Considerations By: MSK
Fd, + Fdft = 28301 Ibf > Fb = 25609 IV
Factor of Safety
Confinn anti -flotation block is sized for minimum factor of safe1y (F,) of 1. 10.
Fs (Fdcs + Fdft)/Fb
1.11 > 1.10
Z:\27842\27842.0002\Engineering\Calculations and Reports\Storm Water\Anti Flotation\27842.0002 - Wet Pond 03 - Anti Flotation
Design Calculations Page 3 of 3