SW3210301_Design Calculations (Stormwater - Phase 3)_20211118

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STORMWATER MANAGEMENT REPORT
FOR:
CRESSWIND WESLEY CHAPEL - PHASE 03
E A L
WESLEY CHAPEL, NC
PREPARED FOR:
KH WESLEY CHAPEL, LLC
IICA�
/
/
THOMAS
& HUTTON
ENGINEERING -
00. _
., No. F-0871 ;
41,
�IlOjlllAO
J - #2 7842.0003
APRIL 1, 2021
REVISED: NOVEMBER 10, 2021
Prepared by:
THOMAS Sc HUTTON

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

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

SECTION 1 - SUMMARY OF RESULTS
Table 1 - Pre Development Runoff Rates
TABLE 1
Summary of Results - Existing Conditions
Storm Event
Outfall 01
(cfs)
2-year
56
10-Year
122
25-Year
160
50-Year
195
Table 2- Post Development Runoff Rates
TABLE 1
Summa of Results - Proposed Conditions
Storm Event
Outfall 01
cfs
2-year
34
10-Year
82
25-Year
110
50-Year
135
H THOMAS & HUTTON
Page 3

SECTION 2 - PROJECT NARRATIVE
Cresswind is a residential subdivision within Wesley Chapel, North Carolina. Phase 3 consists of
approximately 129 single family detached units. The site is located in Union County along Potter
Road, north of Newtown Road and south of Weddington Road. It should be noted that a portion
of Phase 4 lots and impervious area is included in the post development calculations for the
proposed pond.
The majority of the site is currently wooded with an understory of brush. Pre -development run-
off is discharged into an existing wetland system and FEMA Floodplain. The pre -development
drainage basins have been delineated and are illustrated on the Pre -Development Drainage
Exhibit found at the end of this report.
For the purpose of this report we will compare the predevelopment runoff rates to the post
development runoff rates as shown in the summary at the beginning of this report. The pre -
development basin will be routed through one wet detention pond during post development
conditions and outfall into the existing wetlands and floodplain.
The post -development sub -basins were delineated and are illustrated on the Post -Development
Drainage Exhibit found at the end of this report. All design information for ponds and associated
drainage pipes and structures can be found in the appendices of this report.
The soils on this site consist of type B, C and D hydrologic soil groups which are shown on the
attached NRCS soils map within Appendix A.
SECTION 3 - PURPOSE
The purposes of this report are:
1. To delineate all pre -development basins that are within this project and determine
which drainage basins will be affected by the proposed development.
2. To develop a stormwater model that will:
a. Be in compliance with the NCDEQ stormwater regulations.
b. Simulate the pre- and post -development conditions for the project.
c. Predict water elevations for all proposed ponds.
d. Demonstrate that all culverts are of adequate size for drainage under post -
development conditions.
e. Provide design flows (under future build out conditions) for the major drainage
structures that can be used to properly size improvements, if needed.
3. To document that the stormwater management measures and equipment installed
on site will be adequate for all existing and proposed development on the site.
Two drainage models are included in this report;
• Pre -Development: examines the drainage basin prior to any development within the site.
• Post -Development: examines the drainage basin after site improvements have been
installed. The model may need to be revised and updated for each phase that is
permitted.
H THOMAS & HUTTON
Page 4

SECTION 4 - REGULATORY SUMMARY
NCDEQ - Stormwater
The North Carolina Department of Environmental Quality (NCDEQ) is responsible for
administering the storm water management program.
Development or re -development activities are required to apply for and receive a stormwater
permit from NCDEQ. These permits address water quality and quantity.
NCDEQ regulations require that peak post -development discharge rates from the basin shall be
at or below pre -development rates for the 10 and 25-year storms events. The regulations also
specify the 1-inch volume drawdown shall be released over a time of 48 to 120 hours to minimize
hydrologic impacts to the receiving channel. See attached Exhibit E for post -development peak
flow control calculations, and Exhibit F for water quality calculations.
The stormwater treatment shall be designed to achieve average annual 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.
H THOMAS & HUTTON
Page 5

The model's hydraulic input data consists of a system of nodes and links. Nodes represent
locations where flows enter or exit the system, pipe or channel characteristics change, or where
stage/storage/time relationships are provided. Links represent traditional types of hydraulic
conveyance such as pipes, channels, control structures, weirs, etc. The sizes, inverts, lengths, and
Manning "n" values for all pipes connecting the ponds or lakes are input into the model. In
addition to pipe information, all pond, lake, and detention area stage -area information and the
respective control structure information is input into the model. The node and link conditions are
analyzed within the model for a given storm, and flow conditions are determined.
Hydrographs for each drainage area are merged within the SSA program, and the hydrologic
results are then combined with the hydraulic information to model the hydraulic interactions of
the entire drainage system. The results include pond area and discharge rates and stage/storage
information during the storm events.
The storm drainage infrastructure onsite was modelled using the Storm Sewers program developed
by Autodesk. This program utilizes the model rainfall and stormwater runoff through the storm
drainage infrastructure to provide hydraulic grade line calculations and profiles for analyzing the
proposed storm drain network.
SECTION 6 - HYDROLOGY
■ SCS TR-55 Method was used.
The rainfall 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
- 10-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
- 100-year, 24-hour Design Storm
= 7.50 inches
SCS Type II Statistical Rainfall Distribution was used. This distribution pattern is determined
by the Soil Conservation Service comparing regional rain -gage data.
Soils present on site consist of the following:
- Badin channery silty clay loam, 2 to 8 percent slopes (BdB2) - HSG C
- Chewacla silt loam, 0 to 2 percent slopes (ChA) - HSG B/D
- Goldstone-Badin complex (GsC), 8 to 15 percent slopes - HSG C
- Tarrus gravelly silty clay loam, 2 to 8 percent slopes (TbB2) - HSG B
SECTION 7 - RUNOFF CALCULATIONS
Peak flow rates for the watersheds were calculated by the SSA Program for each design storm. The
pre- and post -development drainage basins are shown in appendicies that follow this report.
Curve Numbers
H THOMAS & HUTTON
Page 6

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
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)a.s
t1 — P2 0.05 X S
0.4
Shallow Concentrated Flow: (hr)
L
_
tZ 3600 X V
Channel Flow: (hr)
L
_
t3 3600 X V
Time of Concentration: (hr)
t, = t1 + tZ + t3
Symbol
Dimension
Units
n
Manning's n
--
L
Length of flow
ft
P2
2 yr event
rainfall
in
S
Slope
ft/ft
Symbol
Dimension
Units
L
Length of flow
ft
V*
Velocity
ft/s
*Based on TR-55 velocity -slope relationship
Symbol
Dimension
Units
L
Length of flow
ft
V*
Velocity
ft/s
*Assumed to be 2 ft/s
Appendices C and E with time of concentration information are attached.
Mr.
THOMAS & HUTTON
Page 7

SECTION 8 - EXISTING CONDITIONS
The total acreage of the drainage basins analyzed in the stormwater calculations is
approximately 55 acres. The existing conditions described in this narrative will refer to the pre -
development condition of the site. The pre -development conditions for the site consists
predominantly of woods with an understory of brush.
Stormwater runoff on the site was delineated according to the existing drainage patterns found
at the site and upon the field topographic survey completed within the site. The watershed
delineation was conducted to provide a comparison for pre -development and post -
development flows. Outfall "01 " discharges into an existing wetland (See Pre Development
Drainage Map - Appendix B) .
SECTION 9 - POST - DEVELOPMENT CONDITIONS
The post -development drainage basins are shown on the Post -Development conditions
watershed map located in Appendix D of this report. The total post -development watershed
area analyzed for this project is approximately 18 acres. This site maintains all pre -development
discharge points in the post -development condition. Post -development peak flows are less than
pre -development conditions for the 2-yr, 10-yr, and 25-yr storm events. See Appendices B
through H for pre- and post -development SSA model input and results. See Summary of pre -
development versus post -development results at the beginning of report.
After development, the site will consist of approximately 76 single family lots in Phase 2 and 96 lots
in a future phase, public roads, private driveways, and stormwater management features such
as drainage swales and stormwater detention ponds. It should be noted that a portion of Phase
4 lots and impervious area is included in the post development calculations for the proposed
pond. Stormwater runoff from site will be conveyed to a proposed wet detention pond. The
detention pond will meet NCDEQ pre- and post -development flows and meet freeboard
requirements for the ten (10) year, twenty-five (25) year, and fifty (50) year storm events.
The proposed detention ponds were designed to meet criteria found in the NCDEQ BMP Design
Manual. Additionally, the required freeboard has been provided beneath the emergency
spillways and the pond embankments for the (50) year storm event. The following tables illustrate
the maximum water surface elevation for the two (2) year, ten (10) year, twenty-five (25) year, and
fifty (50) year storm events both ponds.
H THOMAS & HUTTON

Table 3 - Wet Detention Pond 04
Bottom of Pond = 562.50
Crest of Emergency Spillway = 572.75
Top of Embankment = 573.00
Wet Detention Pond 04
Storm Event
Max Elevation
(ft)
10-Year
570.53
25-Year
571.12
50-Year
571.62
100-Year
571.99
H THOMAS & HUTTON
Page 9

STORMWATER MANAGEMENT REPORT
CRESSWIND WESLEY CHAPEL - PHASE 03
APPENDIX A
PROJECT MAPPING
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Hydrologic Soil Group —Union County, North Carolina
(SHP)
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Soil MaN may not he valiel at this Scale.
34o 58' 53" N
529700 529800 529900 530000 530100 530200
Map Scale: 1:5,100 if printed on A landscape (11" x 8.5") sheet.
Meters
$ N 0 50 100 200 300
Feet
0 200 400 800 1200
Map projection: Web Mercator Conermordinates: WGS84 Edge tics: UTM Zone 17N WGS84
usoA Natural Resources Web Soil Survey
Conservation Service National Cooperative Soil Survey
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530700
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Pagel of 4

Hydrologic Soil Group —Union County, North Carolina
(SHP)
MAP LEGEND
Area of Interest (AOI)
0
Area of Interest (AOI)
Soils
Soil Rating
Polygons
0
A
0
A/D
0
B
0
B/D
C
0
C/D
0
D
0
Not rated or not available
Soil Rating
Lines
r 0
A
r 0
A/D
B
B/D
N 0
C
r 0
C/D
r 0
D
r 0
Not rated or not available
Soil Rating
Points
0
A
0
A/D
0
B
0
B/D
❑ C
0 C/D
0 D
❑ Not rated or not available
Water Features
Streams and Canals
Transportation
— Rails
­0 Interstate Highways
US Routes
Major Roads
Local Roads
Background
D6 Aerial Photography
MAP INFORMATION
The soil surveys that comprise your AOI were mapped at
1:24,000.
Warning: Soil Map may not be valid at this scale.
Enlargement of maps beyond the scale of mapping can cause
misunderstanding of the detail of mapping and accuracy of soil
line placement. The maps do not show the small areas of
contrasting soils that could have been shown at a more detailed
scale.
Please rely on the bar scale on each map sheet for map
measurements.
Source of Map: Natural Resources Conservation Service
Web Soil Survey URL:
Coordinate System: Web Mercator (EPSG:3857)
Maps from the Web Soil Survey are based on the Web Mercator
projection, which preserves direction and shape but distorts
distance and area. A projection that preserves area, such as the
Albers equal-area conic projection, should be used if more
accurate calculations of distance or area are required.
This product is generated from the USDA-NRCS certified data as
of the version date(s) listed below.
Soil Survey Area: Union County, North Carolina
Survey Area Data: Version 20, Jun 3, 2020
Soil map units are labeled (as space allows) for map scales
1:50,000 or larger.
Date(s) aerial images were photographed: Jul 18, 2011—Oct 30,
2018
The orthophoto or other base map on which the soil lines were
compiled and digitized probably differs from the background
imagery displayed on these maps. As a result, some minor
shifting of map unit boundaries may be evident.
usoA Natural Resources Web Soil Survey 2/22/2021
Conservation Service National Cooperative Soil Survey Page 2 of 4

Hydrologic Soil Group —Union County, North Carolina
1.9:1N
Hydrologic Soil Group
Map unit symbol
Map unit name
Rating
Acres in AOI
Percent of AOI
BdB2
Badin channery silty
C
28.5
51.8%
clay loam, 2 to 8
percent slopes,
moderately eroded
ChA
Chewacla silt loam, 0 to
B/D
7.1
12.9%
2 percent slopes,
frequently flooded
GsC
Goldston-Badin
D
8.9
16.1 %
complex, 8 to 15
percent slopes
TbB2
Tarrus gravelly silty clay
B
10.6
19.2%
loam, 2 to 8 percent
slopes, moderately
eroded
Totals for Area of Interest
66.1
100.0%
USDA Natural Resources Web Soil Survey 2/22/2021
Conservation Service National Cooperative Soil Survey Page 3 of 4

Hydrologic Soil Group —Union County, North Carolina
1.9:1N
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 2/22/2021
Conservation Service National Cooperative Soil Survey Page 4 of 4

National Flood Hazard Layer FI RMette
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FEMA
mob-
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Zone E '
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0 250 500 1,000 1,500 2,000
Basemap: USGS National Map: Orthoimagery: Data refreshed October, 2020
Legend
SEE FIS REPORT FOR DETAILED LEGEND AND INDEX MAP FOR FIRM PANEL LAYOUT
Without Base Flood Elevation (BFE)
Zone A, V, A99
SPECIAL FLOOD
With BFE or Depth ZoneAE, AO, AH, VE, AR
HAZARD AREAS
Regulatory Floodway
OTHER AREAS OF
FLOOD HAZARD
0.2% Annual Chance Flood Hazard, Areas
of 1% annual chance flood with average
depth less than one foot or with drainage
areas of less than one square mile Zonex
Future Conditions 1% Annual
4 '- Chance Flood Hazard Zonex
"Area with Reduced Flood Risk due to
Levee. See Notes. zone
" Area with Flood Risk due to Leveezone D
NO SCREEN Area of Minimal Flood Hazard
Q Effective LOMRs
OTHER AREAS
Area of Undetermined Flood Hazard
GENERAL
- — - - Channel, Culvert, or Storm Sewer
STRUCTURES
IIIIIII Levee, Dike, or Floodwall
e zo.z Cross Sections with 1% Annual Chance
17.5 Water Surface Elevation
a - - - Coastal Transect
—sfa— Base Flood Elevation Line (BFE)
Limit of Study
Jurisdiction Boundary
— --- Coastal Transect Baseline
OTHER
_ Profile Baseline
FEATURES
Hydrographic Feature
Digital Data Available AN
0 No Digital Data Available
MAP PANELS
® Unmapped
QThe
pin displayed on the map is an approximate
point selected by the user and does not represent
an authoritative property location.
This map complies with FEMA's standards for the use of
digital flood maps if it is not void as described below.
The basemap shown complies with FEMA's basemap
accuracy standards
The flood hazard information is derived directly from the
authoritative NFHL web services provided by FEMA. This map
was exported on 2/22/2021 at 6:05 PM and does not
reflect changes or amendments subsequent to this date and
time. The NFHL and effective information may change or
become superseded by new data overtime.
This map image is void if the one or more of the following map
elements do not appear: basemap imagery, flood zone labels,
legend, scale bar, map creation date, community identifiers,
FIRM panel number, and FIRM effective date. Map images for
unmapped and unmodernized areas cannot be used for
regulatory purposes.

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

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/ - - BASIN
\�\ suB-03
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Tc: 36
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S
PRE -DEVELOPMENT
DRAINAGE EXHIBIT
E
CRESSWIND PHASE 2
MONROE, NC
PREPARED FOR:
KH WESLEY CHAPEL, LLC
PREPARED BY:
\ THOMAS
HUTTON
1020 Euclid Avenue
Charlotte, NC 28202 • 980.201.5505
w vw.thomasandhutton.com
JOB NO:
J-27842.0002
DATE:
2/16/2021
DRAWN:
KSC
SCALE:
1"= 180'
REVIEWED:
MSK
SHEET:
N/A

STORMWATER MANAGEMENT REPORT
CRESSWIND WESLEY CHAPEL - PHASE 03
APPENDIX C
PRE -DEVELOPMENT CONDITIONS
DRAINAGE CALCULATIONS
27842.0003
Fq THOMAS Sc HUTTON

27842.0003
CRESSWIND WESLEY CHAPEL - PHASE 03
PRE -DEVELOPMENT BASINS MODEL

Post -Development 002 - Year Page 1
Project Description
File Name .................................................... 27842.0003 - PRE.SPF
Project Options
Flow Units ---------------------------------------------------
CFS
Elevation Type
Elevation
Hydrology Method .
SCS TR-55
Time of Concentration (TOC) Method --------
SCS TR-55
Link Routing Method
Hydrodynamic
Enable Overflow Ponding at Nodes ------------
YES
Skip Steady State Analysis Time Periods ---
NO
Analysis Options
Start Analysis On .
Dec 03, 2019
00:00:00
End Analysis On .
Dec 04, 2019
00:00:00
Start Reporting On .
Dec 03, 2019
00:00:00
Antecedent Dry Days
0
days
Runoff (Dry Weather) Time Step ----------------
0 01:00:00
days hh:mm:ss
Runoff (Wet Weather) Time Step ---------------
0 00:05:00
days hh:mm:ss
Reporting Time Step -----------------------------------
0 00:05:00
days hh:mm:ss
Routing Time Step --------------------------------------
15
seconds
Number of Elements
Qty
Rain Gages
1
Subbasins
1
Nodes
1
Junctions
0
Outfalls
1
Flow Diversions
0
Inlets
0
Storage Nodes
0
Links
0
Channels
0
Pipes
0
Pumps
0
Orifices
0
Weirs
0
Outlets
0
Pollutants
0
Land Uses
0
Rainfall Details
SN Rain Gage Data Data Source Rainfall Rain State County Return Rainfall Rainfall
ID Source ID Type Units Period Depth Distribution
(years) (inches)
1 Time Series TS-002 Intensity inches North Carolina Union 2 3.50 SCS Type II 247hr

Post -Development 002 - Year Page 2
Subbasin Summary
SN Subbasin Area Peak Rate Weighted
ID Factor Curve
Number
Total Total Total Peak Time of
Rainfall Runoff Runoff Runoff Concentration
Volume
(ac) (in) (in) (ac-in) (cfs) (days hh:mm:ss)
1 SUB-01 55.97 0.00 73.00 3.50 1.18 66.04 56.55 0 0028:45

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

Post -Development 002 - Year
Subbasin Hydrology
Page 4
Subbasin : SUB-01
Input Data
Area(ac)------------------------------------------------------------------------
55-97
Peak Rate Factor-----------------------------------------------------------
0-00
Weighted Curve Number-----------------------------------------------
73-00
Rain Gage ID
Composite Curve Number
Area
Soil Curve
Soil/Surface Description
(acres)
Group Number
55-97
- 73-00
Composite Area & Weighted CN
55-97
73-00
Time of Concentration
TOC Method : SCS TR-55
Sheet Flow Equation :
Tc = (0-007 * ((n * Lf)^0-8)) / ((P^0-5) * (Sf^0-4))
Where :
Tc =
Time of Concentration (hr)
n =
Manning's roughness
Lf =
Flow Length (ft)
P =
2 yr, 24 hr Rainfall (inches)
Sf =
Slope (ft/ft)
Shallow Concentrated Flow Equation :
V = 16-1345 * (Sf^0-5) (unpaved surface)
V = 20-3282 * (Sf^0-5) (paved surface)
V = 15-0 * (Sf^0-5) (grassed waterway surface)
V = 10-0 * (Sf^0-5) (nearly bare & untilled surface)
V = 9-0 * (Sf^0-5) (cultivated straight rows surface)
V = 7-0 * (Sf^0-5) (short grass pasture surface)
V = 5-0 * (Sf^0-5) (woodland surface)
V = 2-5 * (Sf^0-5) (forest w/heavy litter surface)
Tc = (Lf / V) / (3600 sec/hr)
Where
Tc = Time of Concentration (hr)
Lf = Flow Length (ft)
V = Velocity (ft/sec)
Sf = Slope (ft/ft)
Channel Flow Equation:
V = (1-49 * (R^(2/3)) * (Sf^0-5)) / n
R =Aq/Wp
Tc = (Lf / V) / (3600 sec/hr)
Where :
Tc =
Time of Concentration (hr)
Lf =
Flow Length (ft)
R =
Hydraulic Radius (ft)
Aq =
Flow Area (W)
Wp
= Wetted Perimeter (ft)
V =
Velocity (ft/sec)
Sf =
Slope (ft/ft)
n =
Manning's roughness

Post -Development 002 - Year Page 5

Post -Development 002 - Year Page 6
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) ------------------
Subbasin Runoff Results
Flowpath
Flowpath Flowpath
A
B
C
3
0.00
0.00
100
0.00
0.00
4
0.00
0.00
3.50
0.00
0.00
0.13
0.00
0.00
12.36
0.00
0.00
Flowpath
Flowpath
Flowpath
A
B
C
2460
0.00
0.00
2.4
0.00
0.00
Unpaved
Unpaved
Unpaved
2.50
0.00
0.00
16.40
0.00
0.00
Total Rainfall (in)------------------------------------------------------------ 3.50
Total Runoff (in)------------------------------------------------------------- 1.18
Peak Runoff (cfs)----------------------------------------------------------- 56.55
Weighted Curve Number----------------------------------------------- 73.00
Time of Concentration (days hh:mm:ss)------------------------ 0 0028:46

Post -Development 002 - Year Page 7

Post -Development 002 - Year Page 8
Subbasin : SUB-01
5
4.8
4.6
4.4
4.2
4
3.8
3.6
3.4
3.2
3
-E� 2.8
_— 2.6
2.4
2.2
Fr, 2
1.8
1.6
1.4
1.2
1
0.8
0.6
0.4
02
N
L]
Rainfall Intensity Graph
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23
Time (hrs)
Runoff Hydrograph
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23
Time (hrs)

Post -Development 002 - Year Page 9

Post -Development 010 - Year Page 1
Project Description
File Name .................................................... 27842.0003 - PRE.SPF
Project Options
Flow Units ---------------------------------------------------
CFS
Elevation Type
Elevation
Hydrology Method .
SCS TR-55
Time of Concentration (TOC) Method --------
SCS TR-55
Link Routing Method
Hydrodynamic
Enable Overflow Ponding at Nodes ------------
YES
Skip Steady State Analysis Time Periods ---
NO
Analysis Options
Start Analysis On .
Dec 03, 2019
00:00:00
End Analysis On .
Dec 04, 2019
00:00:00
Start Reporting On .
Dec 03, 2019
00:00:00
Antecedent Dry Days
0
days
Runoff (Dry Weather) Time Step ----------------
0 01:00:00
days hh:mm:ss
Runoff (Wet Weather) Time Step ---------------
0 00:05:00
days hh:mm:ss
Reporting Time Step -----------------------------------
0 00:05:00
days hh:mm:ss
Routing Time Step --------------------------------------
15
seconds
Number of Elements
Qty
Rain Gages
1
Subbasins
1
Nodes
1
Junctions
0
Outfalls
1
Flow Diversions
0
Inlets
0
Storage Nodes
0
Links
0
Channels
0
Pipes
0
Pumps
0
Orifices
0
Weirs
0
Outlets
0
Pollutants
0
Land Uses
0
Rainfall Details
SN Rain Gage Data Data Source Rainfall Rain State County Return Rainfall Rainfall
ID Source ID Type Units Period Depth Distribution
(years) (inches)
1 Time Series TS-010 Intensity inches North Carolina Union 10 520 SCS Type II 247hr

Post -Development 010 - Year Page 2
Subbasin Summary
SIN Subbasin Area Peak Rate Weighted
ID Factor Curve
Number
Total Total Total Peak Time of
Rainfall Runoff Runoff Runoff Concentration
Volume
(ac) (in) (in) (ac-in) (cfs) (days hh:mm:ss)
1 SUB-01 55.97 0.00 73.00 5.20 2.44 136.45 122.70 0 00:28:45

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

Post -Development 010 - Year
Subbasin Hydrology
Page 4
Subbasin : SUB-01
Input Data
Area(ac)------------------------------------------------------------------------
55-97
Peak Rate Factor-----------------------------------------------------------
0-00
Weighted Curve Number-----------------------------------------------
73-00
Rain Gage ID
Composite Curve Number
Area
Soil Curve
Soil/Surface Description
(acres)
Group Number
55-97
- 73-00
Composite Area & Weighted CN
55-97
73-00
Time of Concentration
TOC Method : SCS TR-55
Sheet Flow Equation :
Tc = (0-007 * ((n * Lf)^0-8)) / ((P^0-5) * (Sf^0-4))
Where :
Tc =
Time of Concentration (hr)
n =
Manning's roughness
Lf =
Flow Length (ft)
P =
2 yr, 24 hr Rainfall (inches)
Sf =
Slope (ft/ft)
Shallow Concentrated Flow Equation :
V = 16-1345 * (Sf^0-5) (unpaved surface)
V = 20-3282 * (Sf^0-5) (paved surface)
V = 15-0 * (Sf^0-5) (grassed waterway surface)
V = 10-0 * (Sf^0-5) (nearly bare & untilled surface)
V = 9-0 * (Sf^0-5) (cultivated straight rows surface)
V = 7-0 * (Sf^0-5) (short grass pasture surface)
V = 5-0 * (Sf^0-5) (woodland surface)
V = 2-5 * (Sf^0-5) (forest w/heavy litter surface)
Tc = (Lf / V) / (3600 sec/hr)
Where
Tc = Time of Concentration (hr)
Lf = Flow Length (ft)
V = Velocity (ft/sec)
Sf = Slope (ft/ft)
Channel Flow Equation:
V = (1-49 * (R^(2/3)) * (Sf^0-5)) / n
R =Aq/Wp
Tc = (Lf / V) / (3600 sec/hr)
Where :
Tc =
Time of Concentration (hr)
Lf =
Flow Length (ft)
R =
Hydraulic Radius (ft)
Aq =
Flow Area (W)
Wp
= Wetted Perimeter (ft)
V =
Velocity (ft/sec)
Sf =
Slope (ft/ft)
n =
Manning's roughness

Post -Development 010 - Year Page 5

Post -Development 010 - Year Page 6
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) ------------------
Subbasin Runoff Results
Flowpath
Flowpath Flowpath
A
B
C
3
0.00
0.00
100
0.00
0.00
4
0.00
0.00
3.50
0.00
0.00
0.13
0.00
0.00
12.36
0.00
0.00
Flowpath
Flowpath
Flowpath
A
B
C
2460
0.00
0.00
2.4
0.00
0.00
Unpaved
Unpaved
Unpaved
2.50
0.00
0.00
16.40
0.00
0.00
Total Rainfall (in)------------------------------------------------------------ 520
Total Runoff (in)------------------------------------------------------------- 2.44
Peak Runoff (cfs)----------------------------------------------------------- 122.70
Weighted Curve Number----------------------------------------------- 73.00
Time of Concentration (days hh:mm:ss)------------------------ 0 0028:46

Post -Development 010 - Year Page 7

Post -Development 010 - Year Page 8
Subbasin : SUB-01
7.5
7
6.5
6
5.5
5
4.6
4
3.5
Fr, 3
2.5
2
1.5
0.5
125
120
115
110
105
100
95
90
85
80
75
N
70
65
0
60
55
50
45
40
35
30
25
20
15
10
5
Rainfall Intensity Graph
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23
Time (hrs)
Runoff Hydrograph
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23
Time (hrs)

Post -Development 010 - Year Page 9

Post -Development 025 - Year Page 1
Project Description
File Name .................................................... 27842.0003 - PRE.SPF
Project Options
Flow Units ---------------------------------------------------
CFS
Elevation Type
Elevation
Hydrology Method .
SCS TR-55
Time of Concentration (TOC) Method --------
SCS TR-55
Link Routing Method
Hydrodynamic
Enable Overflow Ponding at Nodes ------------
YES
Skip Steady State Analysis Time Periods ---
NO
Analysis Options
Start Analysis On .
Dec 03, 2019
00:00:00
End Analysis On .
Dec 04, 2019
00:00:00
Start Reporting On .
Dec 03, 2019
00:00:00
Antecedent Dry Days
0
days
Runoff (Dry Weather) Time Step ----------------
0 01:00:00
days hh:mm:ss
Runoff (Wet Weather) Time Step ---------------
0 00:05:00
days hh:mm:ss
Reporting Time Step -----------------------------------
0 00:05:00
days hh:mm:ss
Routing Time Step --------------------------------------
15
seconds
Number of Elements
Qty
Rain Gages
1
Subbasins
1
Nodes
1
Junctions
0
Outfalls
1
Flow Diversions
0
Inlets
0
Storage Nodes
0
Links
0
Channels
0
Pipes
0
Pumps
0
Orifices
0
Weirs
0
Outlets
0
Pollutants
0
Land Uses
0
Rainfall Details
SN Rain Gage Data Data Source Rainfall Rain State County Return Rainfall Rainfall
ID Source ID Type Units Period Depth Distribution
(years) (inches)
1 Time Series TS-025 Intensity inches North Carolina Union 25 6.10 SCS Type II 247hr

Post -Development 025 - Year Page 2
Subbasin Summary
SN Subbasin Area Peak Rate Weighted
ID Factor Curve
Number
Total Total Total Peak Time of
Rainfall Runoff Runoff Runoff Concentration
Volume
(ac) (in) (in) (ac-in) (cfs) (days hh:mm:ss)
1 SUB-01 55.97 0.00 73.00 6.10 3.17 177.54 160.63 0 0028:45

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

Post -Development 025 - Year
Subbasin Hydrology
Page 4
Subbasin : SUB-01
Input Data
Area(ac)------------------------------------------------------------------------
55-97
Peak Rate Factor-----------------------------------------------------------
0-00
Weighted Curve Number-----------------------------------------------
73-00
Rain Gage ID
Composite Curve Number
Area
Soil Curve
Soil/Surface Description
(acres)
Group Number
55-97
- 73-00
Composite Area & Weighted CN
55-97
73-00
Time of Concentration
TOC Method : SCS TR-55
Sheet Flow Equation :
Tc = (0-007 * ((n * Lf)^0-8)) / ((P^0-5) * (Sf^0-4))
Where :
Tc =
Time of Concentration (hr)
n =
Manning's roughness
Lf =
Flow Length (ft)
P =
2 yr, 24 hr Rainfall (inches)
Sf =
Slope (ft/ft)
Shallow Concentrated Flow Equation :
V = 16-1345 * (Sf^0-5) (unpaved surface)
V = 20-3282 * (Sf^0-5) (paved surface)
V = 15-0 * (Sf^0-5) (grassed waterway surface)
V = 10-0 * (Sf^0-5) (nearly bare & untilled surface)
V = 9-0 * (Sf^0-5) (cultivated straight rows surface)
V = 7-0 * (Sf^0-5) (short grass pasture surface)
V = 5-0 * (Sf^0-5) (woodland surface)
V = 2-5 * (Sf^0-5) (forest w/heavy litter surface)
Tc = (Lf / V) / (3600 sec/hr)
Where
Tc = Time of Concentration (hr)
Lf = Flow Length (ft)
V = Velocity (ft/sec)
Sf = Slope (ft/ft)
Channel Flow Equation:
V = (1-49 * (R^(2/3)) * (Sf^0-5)) / n
R =Aq/Wp
Tc = (Lf / V) / (3600 sec/hr)
Where :
Tc =
Time of Concentration (hr)
Lf =
Flow Length (ft)
R =
Hydraulic Radius (ft)
Aq =
Flow Area (W)
Wp
= Wetted Perimeter (ft)
V =
Velocity (ft/sec)
Sf =
Slope (ft/ft)
n =
Manning's roughness

Post -Development 025 - Year Page 5

Post -Development 025 - Year Page 6
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) ------------------
Subbasin Runoff Results
Flowpath
Flowpath Flowpath
A
B
C
3
0.00
0.00
100
0.00
0.00
4
0.00
0.00
3.50
0.00
0.00
0.13
0.00
0.00
12.36
0.00
0.00
Flowpath
Flowpath
Flowpath
A
B
C
2460
0.00
0.00
2.4
0.00
0.00
Unpaved
Unpaved
Unpaved
2.50
0.00
0.00
16.40
0.00
0.00
Total Rainfall (in)------------------------------------------------------------ 6.10
Total Runoff (in)------------------------------------------------------------- 3.17
Peak Runoff (cfs)----------------------------------------------------------- 160.63
Weighted Curve Number----------------------------------------------- 73.00
Time of Concentration (days hh:mm:ss)------------------------ 0 0028:46

Post -Development 025 - Year Page 7

Post -Development 025 - Year Page 8
Subbasin : SUB-01
8.5
8
7.5
7
6.5
6
5.5
5
4.5
4
3.5
3
2.5
2
1.5
0.5
180
170
160
150
140
130
120
110
100
0
90
80
70
60
50
40
30
20
10
Rainfall Intensity Graph
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23
Time (hrs)
Runoff Hydrograph
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23
Time (hrs)

Post -Development 025 - Year Page 9

Post -Development 050 - Year Page 1
Project Description
File Name .................................................... 27842.0003 - PRE.SPF
Project Options
Flow Units ---------------------------------------------------
CFS
Elevation Type
Elevation
Hydrology Method .
SCS TR-55
Time of Concentration (TOC) Method --------
SCS TR-55
Link Routing Method
Hydrodynamic
Enable Overflow Ponding at Nodes ------------
YES
Skip Steady State Analysis Time Periods ---
NO
Analysis Options
Start Analysis On .
Dec 03, 2019
00:00:00
End Analysis On .
Dec 04, 2019
00:00:00
Start Reporting On .
Dec 03, 2019
00:00:00
Antecedent Dry Days
0
days
Runoff (Dry Weather) Time Step ----------------
0 01:00:00
days hh:mm:ss
Runoff (Wet Weather) Time Step ---------------
0 00:05:00
days hh:mm:ss
Reporting Time Step -----------------------------------
0 00:05:00
days hh:mm:ss
Routing Time Step --------------------------------------
15
seconds
Number of Elements
Qty
Rain Gages
1
Subbasins
1
Nodes
1
Junctions
0
Outfalls
1
Flow Diversions
0
Inlets
0
Storage Nodes
0
Links
0
Channels
0
Pipes
0
Pumps
0
Orifices
0
Weirs
0
Outlets
0
Pollutants
0
Land Uses
0
Rainfall Details
SN Rain Gage Data Data Source Rainfall Rain State County Return Rainfall Rainfall
ID Source ID Type Units Period Depth Distribution
(years) (inches)
1 Time Series TS-050 Intensity inches North Carolina Union 50 6.90 SCS Type II 247hr

Post -Development 050 - Year Page 2
Subbasin Summary
SIN Subbasin Area Peak Rate Weighted
ID Factor Curve
Number
Total Total Total Peak Time of
Rainfall Runoff Runoff Runoff Concentration
Volume
(ac) (in) (in) (ac-in) (cfs) (days hh:mm:ss)
1 SUB-01 55.97 0.00 73.00 6.90 3.85 215.43 195.04 0 00:28:45

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

Post -Development 050 - Year
Subbasin Hydrology
Page 4
Subbasin : SUB-01
Input Data
Area(ac)------------------------------------------------------------------------
55-97
Peak Rate Factor-----------------------------------------------------------
0-00
Weighted Curve Number-----------------------------------------------
73-00
Rain Gage ID
Composite Curve Number
Area
Soil Curve
Soil/Surface Description
(acres)
Group Number
55-97
- 73-00
Composite Area & Weighted CN
55-97
73-00
Time of Concentration
TOC Method : SCS TR-55
Sheet Flow Equation :
Tc = (0-007 * ((n * Lf)^0-8)) / ((P^0-5) * (Sf^0-4))
Where :
Tc =
Time of Concentration (hr)
n =
Manning's roughness
Lf =
Flow Length (ft)
P =
2 yr, 24 hr Rainfall (inches)
Sf =
Slope (ft/ft)
Shallow Concentrated Flow Equation :
V = 16-1345 * (Sf^0-5) (unpaved surface)
V = 20-3282 * (Sf^0-5) (paved surface)
V = 15-0 * (Sf^0-5) (grassed waterway surface)
V = 10-0 * (Sf^0-5) (nearly bare & untilled surface)
V = 9-0 * (Sf^0-5) (cultivated straight rows surface)
V = 7-0 * (Sf^0-5) (short grass pasture surface)
V = 5-0 * (Sf^0-5) (woodland surface)
V = 2-5 * (Sf^0-5) (forest w/heavy litter surface)
Tc = (Lf / V) / (3600 sec/hr)
Where
Tc = Time of Concentration (hr)
Lf = Flow Length (ft)
V = Velocity (ft/sec)
Sf = Slope (ft/ft)
Channel Flow Equation:
V = (1-49 * (R^(2/3)) * (Sf^0-5)) / n
R =Aq/Wp
Tc = (Lf / V) / (3600 sec/hr)
Where :
Tc =
Time of Concentration (hr)
Lf =
Flow Length (ft)
R =
Hydraulic Radius (ft)
Aq =
Flow Area (W)
Wp
= Wetted Perimeter (ft)
V =
Velocity (ft/sec)
Sf =
Slope (ft/ft)
n =
Manning's roughness

Post -Development 050 - Year Page 5

Post -Development 050 - Year Page 6
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) ------------------
Subbasin Runoff Results
Flowpath
Flowpath Flowpath
A
B
C
3
0.00
0.00
100
0.00
0.00
4
0.00
0.00
3.50
0.00
0.00
0.13
0.00
0.00
12.36
0.00
0.00
Flowpath
Flowpath
Flowpath
A
B
C
2460
0.00
0.00
2.4
0.00
0.00
Unpaved
Unpaved
Unpaved
2.50
0.00
0.00
16.40
0.00
0.00
Total Rainfall (in)------------------------------------------------------------ 6.90
Total Runoff (in)------------------------------------------------------------- 3.85
Peak Runoff (cfs)----------------------------------------------------------- 195.04
Weighted Curve Number----------------------------------------------- 73.00
Time of Concentration (days hh:mm:ss)------------------------ 0 0028:46

Post -Development 050 - Year Page 7

Post -Development 050 - Year Page 8
Subbasin : SUB-01
9.5
9
8.5
8
7.5
7
6.5
6
5.5
5
° 4.5
4
3.5
3
2.5
2
1.5
0.5
210
200
190
180
170
160
150
140
130
N 120
110
100
90
80
70
60
50
40
30
20
10
Rainfall Intensity Graph
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23
Time (hrs)
Runoff Hydrograph
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23
Time (hrs)

Post -Development 050 - Year Page 9

STORMWATER MANAGEMENT REPORT
CRESSWIND WESLEY CHAPEL - PHASE 03
APPENDIX D
POST -DEVELOPMENT
DRAINAGE MAP
►�:�►��I�I�Ii3
A THOMAS Sc HUTTON

-• ::fie:. / < / / / < / / � ' _ _ / __/ _/ " _ /
WET DETEN ••::��w\_� �'e" .. :.
•-:I•-,-L LI--
/ POND I
VIA
OUTFALL 02
WET DETENTIO
POND
SHALLOW
CONCENTRATED/
FLOW: 1102'
\ SHEET FLOW: -�\\r
100' �v I I -_ - vLOW PATH v v
HATCH LEGEND
PHASE 2 BUA TO POND 03
A <\ / A `�.A �� A<,�� EXISTING /�� / \
('•' h/
PHASE I / /
PHASE 3 BUA TO POND 03 / � -:.•:/ �---: - - `----��'--� ' _
4
PHASE 3 BUA TO POND 04 _ ' \
I — — I• / _ _ SHEET FLOW /
PHASE 4 BUA TO POND 04 / :'/ t �' , — — — L BMP ACCESS EASEMENT
EX \ \
�L __— _ TEND OUT TO EXISTING \
/ ' UNDISTURBED
POTTER ROAD RIGHT OF WAY \ �\� _
y
AREA: 13.14 AC. \
..
_—_
I _ OUGHBY ROA
_ �• : \ _�...... MIN. - '• "' \ \WILL
RIW
o / --�
:;...:
, y� - \I �_— II II'I I'I I'I ;'I lil / �' A
RAINTED HEVRON
PATH -_ -_ -_ - — II pl 1, / / \ // \ \. \ \ / % IN INTRSE TION
;.: �3� j / / - - - - - - L � L _j J L J L J L J � JI'l \� / FUTURE / \ //
II WITH PK NAIL)
' - i L - :x ' .:...................... /% / �/ \ AMENITY /\
' ELEV. s31.
/ :i: _ - - - i •• •• •••••••••••••• ` /r �C PROJECTBENMARK
/� - / \ < > CENTER
y �% < I L — — I ICI \/i •�
�/ y 1- �� - - - �I _ 1. ��. PHASE 2 BASIN TO POND 03 < \/ �,/��•_ / \\ \\\ / \ /
I / / y i - _ = SUB-03
SHALLOW /yI-i - - - - _ AREA. 45.3 AC. /,'/ �// �•� / / \ --
y
/ CONCENTRATED _ _ _ - �� -' CN: 86 G/ \, / ;� ' � i/'\ - I ,,,
/ FLOW: 1370;i_ / Tc: 5 MIN.
- � E �T/ING
// e.<.::'i < - - •I J�J�� // / \ \.\ / /i ./ ��_ \ \ PHASE I r \
--� 1r
/ / •�:... _- - i- - - �f • ICI � l v�v' _�. < /, i �,vyv \\, ��� i .\� / pl Iq � �-- '"" � / vv
4 \ —
IWET DETENTION
UNDISTURBED BASIN POND 03 SUB-02 ry�/
ry / / \ \ / J
AREA: 23.79 AC.
�I Tc: 37 MIN. i l \ r l•l �\ \ \ \ / , I I,I II `II \1 \`\ / \ / \ \ / II 1...,..n,:
IA �NN
' r
< v /
2_ \ UNDISTURBED BASIN / \:
SUB-05
AREA: 43.5 AC. c. _
CN: 73 FUTURE
•/ / � \/ �AyA�_"' �"y/ � VAS � < � . 1 \ _ �' V �v�� � Tc: 32 MIN. PHASE
7k
/
000
< VA VA
�AV A ✓'" ' � \
PHASE 3 BASIN TO POND 04--
�
AREA:--
CN: 86
Tc: 5 MIN.T\\ \\\ \ • - - - - / --
\ I
--
WET DETENTION
POND 04 / IT - I -
FUTURE I FUTURE _
- - -E- _
PHASE- ---T- -
f � ,
\ \ -i
FUTURE STORMWATER
MANAGEMENT \� FUTURE ST MWA R I
BMP \ MANAGEM T
\ \ \ BMP - I
POND 4 I
��- � POND 5 �
�=
OUTFACE 03 —
`' --- -- GRAPHIC SCALE
200 0 100 2 10 400
�
( IN FEET )
� I inch = 200 ft.
,
800
N
W
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a -
JOB NO:
J-27842.0003
DATE:
4/5/21
DRAWN:
KSC
DESIGNED:
DAC
REVIEWED:
MSK
APPROVED:
MSK
SCALE:
I" = 200'
C3*30IIIIIIIIIIIIIIIIIII

STORMWATER MANAGEMENT REPORT
CRESSWIND WESLEY CHAPEL - PHASE 03
APPENDIX E
POST -DEVELOPMENT CONDITIONS
DRAINAGE CALCULATIONS
27842.0003
Fq THOMAS Sc HUTTON

27842.0003
CRESSWIND WESLEY CHAPEL - PHASE 03
POST -DEVELOPMENT BASINS MODEL

Post -Development 002 - Year Page 1
Project Description
File Name .................................................... 27842.0003 - POST.SPF
Project Options
Flow Units ---------------------------------------------------
CFS
Elevation Type
Elevation
Hydrology Method .
SCS TR-55
Time of Concentration (TOC) Method --------
SCS TR-55
Link Routing Method
Hydrodynamic
Enable Overflow Ponding at Nodes ------------
YES
Skip Steady State Analysis Time Periods ---
NO
Analysis Options
Start Analysis On .
Dec 03, 2020
00:00:00
End Analysis On .
Dec 04, 2020
00:00:00
Start Reporting On .
Dec 03, 2020
00:00:00
Antecedent Dry Days
0
days
Runoff (Dry Weather) Time Step ----------------
0 01:00:00
days hh:mm:ss
Runoff (Wet Weather) Time Step ---------------
0 00:05:00
days hh:mm:ss
Reporting Time Step -----------------------------------
0 00:05:00
days hh:mm:ss
Routing Time Step --------------------------------------
15
seconds
Number of Elements
Qty
Rain Gages
1
Subbasins
2
Nodes
4
Junctions
1
Outfalls
2
Flow Diversions
0
Inlets
0
Storage Nodes
1
Links
5
Channels
0
Pipes
1
Pumps
0
Orifices
2
Weirs
2
Outlets
0
Pollutants
0
Land Uses
0
Rainfall Details
SN Rain Gage Data Data Source Rainfall Rain State County Return Rainfall Rainfall
ID Source ID Type Units Period Depth Distribution
(years) (inches)
1 Time Series TS-002 Intensity inches North Carolina Union 2 3.50 SCS Type III 24-hr

Post -Development 002 - Year Page 2
Subbasin Summary
SN Subbasin Area Peak Rate Weighted
ID Factor Curve
Number
Total Total Total Peak Time of
Rainfall Runoff Runoff Runoff Concentration
Volume
(ac) (in) (in) (ac-in) (cfs) (days hh:mm:ss)
1 SUB-04 17.91 0.00 88.62 3.50 2.32 41.60 42.47 0 00-05-00
2 SUB-05 43.54 0.00 73.00 3.50 1.18 51.38 33.54 0 0028:45

Post -Development 002 - Year Page 3
Node Summary
SN Element
Element
Invert Ground/Rim
Initial Surcharge Ponded Peak Max HGL
Max
Min
Time of Total
ID
Type
Elevation
(Max)
Water Elevation
Area Inflow Elevation Surcharge Freeboard
Peak Flooded
Elevation Elevation
Attained
Depth
Attained
Flooding Volume
Attained
Occurrence
(ft)
(ft)
(ft) (ft)
(ft') (cfs) (ft)
(ft)
(ft) (days hh:mm) (ac-in)
1 CONTROL -STRUCTURE
Junction
567.00
573.00
0.00 0.00
1.00 2.65 567.84
0.00
9.66
0 00:00 0.00
2 Emergency-Outffall
Outffall
560.00
0.00 560.00
3 Out-02
Outffall
560.00
33.60 560.00
4 Pond-04
Storage Node
562.50
573.50
567.00
1.00 41.94 569.51
0.00

Post -Development
Total Time
Flooded
(min)
0.00
0.00
002 - Year
Page 4

Post -Development 002 - Year
Page 5
Link Summary
SN Element Element From To (Outlet) Length Inlet Outlet Average Diameter or Manning's Peak Design Flow Peak Flow/ Peak Flow Peak Flow Peak Flow Total Time Reported
ID Type (Inlet) Node Invert Invert Slope Height Roughness Flow Capacity Design Flow Velocity Depth Depth/ Surcharged Condition
Node Elevation Elevation Ratio Total Depth
Ratio
(ft)
(ft)
(ft) ( % )
(in)
(cfs) (cfs) (ft/sec) (ft) (min)
1 Outlet -Pipe Pipe
Out-02 CONTROL -STRUCTURE 89.00
567.00
566.64 0.4000
36.000
0.0150 2.65 1.94 1.37 224 0.67 022 0.00 > CAPACITY
2 CS -RIM Orifice
Pond-04 CONTROL -STRUCTURE
562.50
567.00
60.000
0.00
3 WQ-Orifice-04 Orifice
Pond-04 CONTROL -STRUCTURE
562.50
567.00
3.000
0.32
4 Spillway-04 Weir
Pond-04 Emergency-Outffall
562.50
560.00
0.00
5 Weir-04 Weir
Pond-04 CONTROL -STRUCTURE
562.50
567.00
2.33

Post -Development 002 - Year
Subbasin Hydrology
Page 6
Subbasin : SUB-04
Input Data
Area(ac)------------------------------------------------------------------------
17-91
Peak Rate Factor-----------------------------------------------------------
0-00
Weighted Curve Number-----------------------------------------------
88-62
Rain Gage ID
Composite Curve Number
Area
Soil
Curve
Soil/Surface Description
(acres)
Group
Number
Paved parking & roofs
12.08
B
98-00
Future -Paved parking & roofs
1.29
B
98-00
> 75 % grass cover, Good
4.54
B
61-00
Composite Area & Weighted CN
17.91
88-62
Time of Concentration
TOC Method : SCS TR-55
Sheet Flow Equation :
Tc = (0-007 * ((n * Lf)^0-8)) / ((P^0-5) * (Sf^0-4))
Where :
Tc =
Time of Concentration (hr)
n =
Manning's roughness
Lf =
Flow Length (ft)
P =
2 yr, 24 hr Rainfall (inches)
Sf =
Slope (ft/ft)
Shallow Concentrated Flow Equation :
V = 16-1345 * (Sf^0-5) (unpaved surface)
V = 20-3282 * (Sf^0-5) (paved surface)
V = 15-0 * (Sf^0-5) (grassed waterway surface)
V = 10-0 * (Sf^0-5) (nearly bare & untilled surface)
V = 9-0 * (Sf^0-5) (cultivated straight rows surface)
V = 7-0 * (Sf^0-5) (short grass pasture surface)
V = 5-0 * (Sf^0-5) (woodland surface)
V = 2-5 * (Sf^0-5) (forest w/heavy litter surface)
Tc = (Lf / V) / (3600 sec/hr)
Where
Tc = Time of Concentration (hr)
Lf = Flow Length (ft)
V = Velocity (ft/sec)
Sf = Slope (ft/ft)
Channel Flow Equation:
V = (1-49 * (R^(2/3)) * (Sf^0-5)) / n
R =Aq/Wp
Tc = (Lf / V) / (3600 sec/hr)
Where :
Tc =
Time of Concentration (hr)
Lf =
Flow Length (ft)
R =
Hydraulic Radius (ft)
Aq =
Flow Area (ft)
Wp
= Wetted Perimeter (ft)
V =
Velocity (ft/sec)
Sf =
Slope (ft/ft)
n =
Manning's roughness
User -Defined TOC override (minutes): 5
Subbasin Runoff Results
Total Rainfall (in)------------------------------------------------------------ 3-50
Total Runoff (in)------------------------------------------------------------- 2-32
Peak Runoff (cfs)----------------------------------------------------------- 42-47
Weighted Curve Number----------------------------------------------- 88-62
Time of Concentration (days hh:mm:ss)------------------------ 0 00-05-00

Post -Development 002 - Year Page 7

Post -Development 002 - Year Page 8
Subbasin : SUB-04
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
� 1.3
1.2
1.1
1
0.9
0.8
0.7
0.6
0.5
0.4
0.3
02
0.1
44
42
40
38
36
34
32
30
28
26
� 24
v 22
0
20
18
16
14
12
10
8
6
4
2
Rainfall Intensity Graph
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23
Time [hrs]
Runoff Hydrograph
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23
Time [hrs]

Post -Development 002 - Year Page 9

Post -Development 002 - Year
Subbasin : SUB-05
Page 10
Input Data
Area(ac)------------------------------------------------------------------------ 43.54
Peak Rate Factor----------------------------------------------------------- 0.00
Weighted Curve Number----------------------------------------------- 73.00
RainGage ID-----------------------------------------------------------------
Composite Curve Number
Area Soil Curve
Soil/Surface Description (acres) Group Number
43.54 - 73.00
Composite Area & Weighted CN 43.54 73.00
Time of Concentration
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) ------------------
Subbasin Runoff Results
Flowpath
Flowpath
Flowpath
A
B
C
3
0.00
0.00
100
0.00
0.00
4
0.00
0.00
3.50
0.00
0.00
0.13
0.00
0.00
12.36
0.00
0.00
Flowpath
Flowpath
Flowpath
A
B
C
2460
0.00
0.00
2.4
0.00
0.00
Unpaved
Unpaved
Unpaved
2.50
0.00
0.00
16.40
0.00
0.00
Total Rainfall (in)------------------------------------------------------------ 3.50
Total Runoff (in)------------------------------------------------------------- 1.18
Peak Runoff (cfs)----------------------------------------------------------- 33.54
Weighted Curve Number----------------------------------------------- 73.00
Time of Concentration (days hh:mm:ss)------------------------ 0 0028:46

Post -Development 002 - Year Page 11

Post -Development 002 - Year Page 12
Subbasin : SUB-05
3.1
3
2.9
2.8
2.7
2.6
2.5
2.4
2.3
2.2
2.1
2
1.9
1.8
1.7
v 1.6
1.5
1.4
1.3
1.2
1.1
1
0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
36
34
32
30
28
26
24
22
20
v 18
0
16
14
12
10
8
6
4
2
Rainfall Intensity Graph
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23
Time [hrs]
Runoff Hydrograph
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23
Time [hrs]

Post -Development 002 - Year Page 13

Post -Development 002 - Year Page 14
Pipe Input
SN Element Length Inlet Inlet Outlet Outlet Total Average Pipe Pipe Pipe Manning's Entrance Exit/Bend Additional Initial Flap
ID Invert Invert Invert Invert Drop Slope Shape Diameteror Width Roughness Losses Losses Losses Flow Gate
Elevation Offset Elevation Offset Height
(ft) (ft) (ft) (ft) (ft) (ft) ( % ) (in) (in) (cfs)
1 Outlet -Pipe 89.00 567.00 7.00 566.64 -0.36 0.36 0.4000 CIRCULAR 36.000 36.000 0.0150 0.5000 0.5000 0.0000 0.00 No

Post -Development 002 - Year Page 15
No. of
Barrels

Post -Development 002 - Year Page 16
Pipe Results
SN Element Peak Time of Design Flow Peak Flow/ Peak Flow Travel Peak Flow Peak Flow Total Time Froude Reported
ID Flow Peak Flow Capacity Design Flow Velocity Time Depth Depth/ Surcharged Number Condition
Occurrence Ratio Total Depth
Ratio
(cfs) (days hh:mm) (cfs) (ft/sec) (min) (ft) (min)
1 Outlet -Pipe 2.65 0 1420 1.94 1.37 224 0.66 0.67 022 0.00 > CAPACITY

Post -Development 002 - Year Page 17
Storage Nodes
Storage Node : Pond-04
Input Data
Invert Elevation (ft)--------------------------------------------------------------------
562-50
Max (Rim) Elevation (ft)------------------------------------------------------------
573-50
Max (Rim) Offset (ft)-----------------------------------------------------------------
11-00
Initial Water Elevation (ft)----------------------------------------------------------
567-00
Initial Water Depth (ft)---------------------------------------------------------------
4-50
Ponded Area (ft) -----------------------------------------------------------------------
1-00
Evaporation Loss-----------------------------------------------------------------------
0-00
Outflow Weirs
SIN Element
Weir Flap
Crest
Crest
Length
Weir Total Discharge
ID
Type Gate
Elevation
Offset
Height Coefficient
(ft)
(ft)
(ft)
(ft)
1 Spillway-04
Trapezoidal No
572-75
1025
20-00
0-75 3-33
2 Weir-04
Rectangular No
569-00
6-50
2-00
4-00 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 Bottom
Rectangular No
60-00
60-00
573-00 0-63
2 WQ-Orifice-04 Side
CIRCULAR
No
3-00
567-00 0-61
Output Summary Results
Peak Inflow (cfs)------------------------------------------------------------------------
41-94
Peak Lateral Inflow (cfs)------------------------------------------------------------
41-94
Peak Outflow (cfs)---------------------------------------------------------------------
2-65
Peak Exfiltration Flow Rate (cfm)----------------------------------------------
0-00
Max HGL Elevation Attained (ft)------------------------------------------------
569-51
Max HGL Depth Attained (ft)-----------------------------------------------------
7-01
Average HGL Elevation Attained (ft)-----------------------------------------
56828
Average HGL Depth Attained (ft)----------------------------------------------
5-78
Time of Max HGL Occurrence (days hh:mm)---------------------------
0 14-19
Total Exfiltration Volume (1000-ft3)-------------------------------------------
0-000
Total Flooded Volume (ac-in) -
0
Total Time Flooded (min)
0
Total Retention Time (sec) --------------------------------------------------------
0-00

Post -Development 010 - Year Page 1
Project Description
File Name .................................................... 27842.0003 - POST.SPF
Project Options
Flow Units ---------------------------------------------------
CFS
Elevation Type
Elevation
Hydrology Method .
SCS TR-55
Time of Concentration (TOC) Method --------
SCS TR-55
Link Routing Method
Hydrodynamic
Enable Overflow Ponding at Nodes ------------
YES
Skip Steady State Analysis Time Periods ---
NO
Analysis Options
Start Analysis On .
Dec 03, 2020
00:00:00
End Analysis On .
Dec 04, 2020
00:00:00
Start Reporting On .
Dec 03, 2020
00:00:00
Antecedent Dry Days
0
days
Runoff (Dry Weather) Time Step ----------------
0 01:00:00
days hh:mm:ss
Runoff (Wet Weather) Time Step ---------------
0 00:05:00
days hh:mm:ss
Reporting Time Step -----------------------------------
0 00:05:00
days hh:mm:ss
Routing Time Step --------------------------------------
15
seconds
Number of Elements
Qty
Rain Gages
1
Subbasins
2
Nodes
4
Junctions
1
Outfalls
2
Flow Diversions
0
Inlets
0
Storage Nodes
1
Links
5
Channels
0
Pipes
1
Pumps
0
Orifices
2
Weirs
2
Outlets
0
Pollutants
0
Land Uses
0
Rainfall Details
SN Rain Gage Data Data Source Rainfall Rain State County Return Rainfall Rainfall
ID Source ID Type Units Period Depth Distribution
(years) (inches)
1 Time Series TS-010 Intensity inches North Carolina Union 10 520 SCS Type III 24-hr

Post -Development 010 - Year Page 2
Subbasin Summary
SN Subbasin Area Peak Rate Weighted
ID Factor Curve
Number
Total Total Total Peak Time of
Rainfall Runoff Runoff Runoff Concentration
Volume
(ac) (in) (in) (ac-in) (cfs) (days hh:mm:ss)
1 SUB-04 17.91 0.00 88.62 520 3.92 7028 69.61 0 00-05-00
2 SUB-05 43.54 0.00 73.00 520 2.44 106.15 72.31 0 0028:45

Post -Development 010 - Year Page 3
Node Summary
SN Element
Element
Invert Ground/Rim
Initial Surcharge Ponded Peak Max HGL
Max
Min
Time of Total
ID
Type
Elevation
(Max)
Water Elevation
Area Inflow Elevation Surcharge Freeboard
Peak Flooded
Elevation Elevation
Attained
Depth
Attained
Flooding Volume
Attained
Occurrence
(ft)
(ft)
(ft) (ft)
(ft') (cfs) (ft)
(ft)
(ft) (days hh:mm) (ac-in)
1 CONTROL -STRUCTURE
Junction
567.00
573.00
0.00 0.00
1.00 11.05 568.63
0.00
8.87
0 00:00 0.00
2 Emergency-Outffall
Outffall
560.00
0.00 560.00
3 Out-02
Outffall
560.00
81.52 560.00
4 Pond-04
Storage Node
562.50
573.50
567.00
1.00 68.94 570.53
0.00

Post -Development
Total Time
Flooded
(min)
0.00
0.00
010 - Year
Page 4

Post -Development 010 - Year
Page 5
Link Summary
SN Element Element From To (Outlet) Length Inlet Outlet Average Diameter or Manning's Peak Design Flow Peak Flow/ Peak Flow Peak Flow Peak Flow Total Time Reported
ID Type (Inlet) Node Invert Invert Slope Height Roughness Flow Capacity Design Flow Velocity Depth Depth/ Surcharged Condition
Node Elevation Elevation Ratio Total Depth
Ratio
(ft)
(ft)
(ft) ( % )
(in)
(cfs) (cfs) (ft/sec) (ft) (min)
1 Outlet -Pipe Pipe
Out-02 CONTROL -STRUCTURE 89.00
567.00
566.64 0.4000
36.000
0.0150 11.05 1.94 5.70 3.61 1.34 0.45 0.00 > CAPACITY
2 CS -RIM Orifice
Pond-04 CONTROL -STRUCTURE
562.50
567.00
60.000
0.00
3 WQ-Orifice-04 Orifice
Pond-04 CONTROL -STRUCTURE
562.50
567.00
3.000
0.33
4 Spillway-04 Weir
Pond-04 Emergency-Outffall
562.50
560.00
0.00
5 Weir-04 Weir
Pond-04 CONTROL -STRUCTURE
562.50
567.00
10.71

Post -Development 010 - Year
Subbasin Hydrology
Page 6
Subbasin : SUB-04
Input Data
Area(ac)------------------------------------------------------------------------
17-91
Peak Rate Factor-----------------------------------------------------------
0-00
Weighted Curve Number-----------------------------------------------
88-62
Rain Gage ID
Composite Curve Number
Area
Soil
Curve
Soil/Surface Description
(acres)
Group
Number
Paved parking & roofs
12.08
B
98-00
Future -Paved parking & roofs
1.29
B
98-00
> 75 % grass cover, Good
4.54
B
61-00
Composite Area & Weighted CN
17.91
88-62
Time of Concentration
TOC Method : SCS TR-55
Sheet Flow Equation :
Tc = (0-007 * ((n * Lf)^0-8)) / ((P^0-5) * (Sf^0-4))
Where :
Tc =
Time of Concentration (hr)
n =
Manning's roughness
Lf =
Flow Length (ft)
P =
2 yr, 24 hr Rainfall (inches)
Sf =
Slope (ft/ft)
Shallow Concentrated Flow Equation :
V = 16-1345 * (Sf^0-5) (unpaved surface)
V = 20-3282 * (Sf^0-5) (paved surface)
V = 15-0 * (Sf^0-5) (grassed waterway surface)
V = 10-0 * (Sf^0-5) (nearly bare & untilled surface)
V = 9-0 * (Sf^0-5) (cultivated straight rows surface)
V = 7-0 * (Sf^0-5) (short grass pasture surface)
V = 5-0 * (Sf^0-5) (woodland surface)
V = 2-5 * (Sf^0-5) (forest w/heavy litter surface)
Tc = (Lf / V) / (3600 sec/hr)
Where
Tc = Time of Concentration (hr)
Lf = Flow Length (ft)
V = Velocity (ft/sec)
Sf = Slope (ft/ft)
Channel Flow Equation:
V = (1-49 * (R^(2/3)) * (Sf^0-5)) / n
R =Aq/Wp
Tc = (Lf / V) / (3600 sec/hr)
Where :
Tc =
Time of Concentration (hr)
Lf =
Flow Length (ft)
R =
Hydraulic Radius (ft)
Aq =
Flow Area (ft)
Wp
= Wetted Perimeter (ft)
V =
Velocity (ft/sec)
Sf =
Slope (ft/ft)
n =
Manning's roughness
User -Defined TOC override (minutes): 5
Subbasin Runoff Results
Total Rainfall (in)------------------------------------------------------------ 520
Total Runoff (in)------------------------------------------------------------- 3-92
Peak Runoff (cfs)----------------------------------------------------------- 69-61
Weighted Curve Number----------------------------------------------- 88-62
Time of Concentration (days hh:mm:ss)------------------------ 0 00-05-00

Post -Development 010 - Year Page 7

Post -Development 010 - Year Page 8
Subbasin : SUB-04
4.4
4.2
4
3.8
3.6
3.4
3.2
3
2.8
2.6
2.4
2.2
2
1.8
1.6
1.4
1.2
1
0.8
0.6
0.4
0.2
75
70
65
60
55
50
45
40
0
� 35
30
25
20
15
10
5
Rainfall Intensity Graph
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23
Time [hrs]
Runoff Hydrograph
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23
Time [hrs]

Post -Development 010 - Year Page 9

Post -Development 010 - Year
Subbasin : SUB-05
Page 10
Input Data
Area(ac)------------------------------------------------------------------------ 43.54
Peak Rate Factor----------------------------------------------------------- 0.00
Weighted Curve Number----------------------------------------------- 73.00
RainGage ID-----------------------------------------------------------------
Composite Curve Number
Area Soil Curve
Soil/Surface Description (acres) Group Number
43.54 - 73.00
Composite Area & Weighted CN 43.54 73.00
Time of Concentration
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) ------------------
Subbasin Runoff Results
Flowpath
Flowpath
Flowpath
A
B
C
3
0.00
0.00
100
0.00
0.00
4
0.00
0.00
3.50
0.00
0.00
0.13
0.00
0.00
12.36
0.00
0.00
Flowpath
Flowpath
Flowpath
A
B
C
2460
0.00
0.00
2.4
0.00
0.00
Unpaved
Unpaved
Unpaved
2.50
0.00
0.00
16.40
0.00
0.00
Total Rainfall (in)------------------------------------------------------------ 520
Total Runoff (in)------------------------------------------------------------- 2.44
Peak Runoff (cfs)----------------------------------------------------------- 72.31
Weighted Curve Number----------------------------------------------- 73.00
Time of Concentration (days hh:mm:ss)------------------------ 0 0028:46

Post -Development 010 - Year Page 11

Post -Development 010 - Year Page 12
Subbasin : SUB-05
4.6
4.4
4.2
4
3.8
3.6
3.4
3.2
3
2.8
2.6
2.4
2.2
2
1.8
1.6
1.4
1.2
1
0.8
0.6
0.4
0.2
so
75
70
65
60
55
5o
45
v 40
0
35
30
25
20
15
10
5
Rainfall Intensity Graph
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23
Time [hrs]
Runoff Hydrograph
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23
Time [hrs]

Post -Development 010 - Year Page 13

Post -Development 010 - Year Page 14
Pipe Input
SN Element Length Inlet Inlet Outlet Outlet Total Average Pipe Pipe Pipe Manning's Entrance Exit/Bend Additional Initial Flap
ID Invert Invert Invert Invert Drop Slope Shape Diameteror Width Roughness Losses Losses Losses Flow Gate
Elevation Offset Elevation Offset Height
(ft) (ft) (ft) (ft) (ft) (ft) ( % ) (in) (in) (cfs)
1 Outlet -Pipe 89.00 567.00 7.00 566.64 -0.36 0.36 0.4000 CIRCULAR 36.000 36.000 0.0150 0.5000 0.5000 0.0000 0.00 No

Post -Development 010 - Year Page 15
No. of
Barrels

Post -Development 010 - Year Page 16
Pipe Results
SN Element Peak Time of Design Flow Peak Flow/ Peak Flow Travel Peak Flow Peak Flow Total Time Froude Reported
ID Flow Peak Flow Capacity Design Flow Velocity Time Depth Depth/ Surcharged Number Condition
Occurrence Ratio Total Depth
Ratio
(cfs) (days hh:mm) (cfs) (ft/sec) (min) (ft) (min)
1 Outlet -Pipe 11.05 0 12:40 1.94 5.70 3.61 0.41 1.34 0.45 0.00 > CAPACITY

Post -Development 010 - Year Page 17
Storage Nodes
Storage Node : Pond-04
Input Data
Invert Elevation (ft)--------------------------------------------------------------------
562-50
Max (Rim) Elevation (ft)------------------------------------------------------------
573-50
Max (Rim) Offset (ft)-----------------------------------------------------------------
11-00
Initial Water Elevation (ft)----------------------------------------------------------
567-00
Initial Water Depth (ft)---------------------------------------------------------------
4-50
Ponded Area (ft) -----------------------------------------------------------------------
1-00
Evaporation Loss-----------------------------------------------------------------------
0-00
Outflow Weirs
SIN Element
Weir Flap
Crest
Crest
Length
Weir Total Discharge
ID
Type Gate
Elevation
Offset
Height Coefficient
(ft)
(ft)
(ft)
(ft)
1 Spillway-04
Trapezoidal No
572-75
1025
20-00
0-75 3-33
2 Weir-04
Rectangular No
569-00
6-50
2-00
4-00 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 Bottom
Rectangular No
60-00
60-00
573-00 0-63
2 WQ-Orifice-04 Side
CIRCULAR
No
3-00
567-00 0-61
Output Summary Results
Peak Inflow (cfs)------------------------------------------------------------------------
68-94
Peak Lateral Inflow (cfs)------------------------------------------------------------
68-94
Peak Outflow (cfs)---------------------------------------------------------------------
11-05
Peak Exfiltration Flow Rate (cfm)----------------------------------------------
0-00
Max HGL Elevation Attained (ft)------------------------------------------------
570-53
Max HGL Depth Attained (ft)-----------------------------------------------------
8-03
Average HGL Elevation Attained (ft)-----------------------------------------
568-69
Average HGL Depth Attained (ft)----------------------------------------------
6-19
Time of Max HGL Occurrence (days hh:mm)---------------------------
0 12-39
Total Exfiltration Volume (1000-ft3)-------------------------------------------
0-000
Total Flooded Volume (ac-in) -
0
Total Time Flooded (min)
0
Total Retention Time (sec) --------------------------------------------------------
0-00

Post -Development 025 - Year Page 1
Project Description
File Name .................................................... 27842.0003 - POST.SPF
Project Options
Flow Units ---------------------------------------------------
CFS
Elevation Type
Elevation
Hydrology Method .
SCS TR-55
Time of Concentration (TOC) Method --------
SCS TR-55
Link Routing Method
Hydrodynamic
Enable Overflow Ponding at Nodes ------------
YES
Skip Steady State Analysis Time Periods ---
NO
Analysis Options
Start Analysis On .
Dec 03, 2020
00:00:00
End Analysis On .
Dec 04, 2020
00:00:00
Start Reporting On .
Dec 03, 2020
00:00:00
Antecedent Dry Days
0
days
Runoff (Dry Weather) Time Step ----------------
0 01:00:00
days hh:mm:ss
Runoff (Wet Weather) Time Step ---------------
0 00:05:00
days hh:mm:ss
Reporting Time Step -----------------------------------
0 00:05:00
days hh:mm:ss
Routing Time Step --------------------------------------
15
seconds
Number of Elements
Qty
Rain Gages
1
Subbasins
2
Nodes
4
Junctions
1
Outfalls
2
Flow Diversions
0
Inlets
0
Storage Nodes
1
Links
5
Channels
0
Pipes
1
Pumps
0
Orifices
2
Weirs
2
Outlets
0
Pollutants
0
Land Uses
0
Rainfall Details
SN Rain Gage Data Data Source Rainfall Rain State County Return Rainfall Rainfall
ID Source ID Type Units Period Depth Distribution
(years) (inches)
1 Time Series TS-025 Intensity inches North Carolina Union 25 6.10 SCS Type III 24-hr

Post -Development 025 - Year Page 2
Subbasin Summary
SN Subbasin Area Peak Rate Weighted
ID Factor Curve
Number
Total Total Total Peak Time of
Rainfall Runoff Runoff Runoff Concentration
Volume
(ac) (in) (in) (ac-in) (cfs) (days hh:mm:ss)
1 SUB-04 17.91 0.00 88.62 6.10 4.79 85.79 83.90 0 00-05-00
2 SUB-05 43.54 0.00 73.00 6.10 3.17 138.11 94.59 0 0028:45

Post -Development 025 - Year Page 3
Node Summary
SN Element
Element
Invert Ground/Rim
Initial Surcharge Ponded
Peak Max HGL
Max
Min
Time of Total
ID
Type
Elevation
(Max)
Water Elevation
Area
Inflow
Elevation Surcharge
Freeboard
Peak Flooded
Elevation Elevation
Attained
Depth
Attained
Flooding Volume
Attained
Occurrence
(ft)
(ft)
(ft) (ft)
(ft2)
(cfs)
(ft)
(ft)
(ft) (days hh:mm) (ac-in)
1 CONTROL -STRUCTURE
Junction
567.00
573.00
0.00 0.00
1.00
16.53
569.00
0.00
8.50
0 00:00 0.00
2 Emergency-Outffall
Outffall
560.00
0.00
560.00
3 Out-02
Outffall
560.00
109.58
560.00
4 Pond-04
Storage Node
562.50
573.50
567.00
1.00
8324
571.12
0.00

Post -Development
Total Time
Flooded
(min)
0.00
0.00
025 - Year
Page 4

Post -Development 025 - Year
Page 5
Link Summary
SN Element Element From To (Outlet) Length Inlet Outlet Average Diameter or Manning's Peak Design Flow Peak Flow/ Peak Flow Peak Flow Peak Flow Total Time Reported
ID Type (Inlet) Node Invert Invert Slope Height Roughness Flow Capacity Design Flow Velocity Depth Depth/ Surcharged Condition
Node Elevation Elevation Ratio Total Depth
Ratio
(ft)
(ft)
(ft) ( % )
(in)
(cfs) (cfs) (ft/sec) (ft) (min)
1 Outlet -Pipe Pipe
Out-02 CONTROL -STRUCTURE 89.00
567.00
566.64 0.4000
36.000
0.0150 16.53 1.94 8.53 4.15 1.65 0.55 0.00 > CAPACITY
2 CS -RIM Orifice
Pond-04 CONTROL -STRUCTURE
562.50
567.00
60.000
0.00
3 WQ-Orifice-04 Orifice
Pond-04 CONTROL -STRUCTURE
562.50
567.00
3.000
0.35
4 Spillway-04 Weir
Pond-04 Emergency-Outffall
562.50
560.00
0.00
5 Weir-04 Weir
Pond-04 CONTROL -STRUCTURE
562.50
567.00
16.18

Post -Development 025 - Year
Subbasin Hydrology
Page 6
Subbasin : SUB-04
Input Data
Area(ac)------------------------------------------------------------------------
17-91
Peak Rate Factor-----------------------------------------------------------
0-00
Weighted Curve Number-----------------------------------------------
88-62
Rain Gage ID
Composite Curve Number
Area
Soil
Curve
Soil/Surface Description
(acres)
Group
Number
Paved parking & roofs
12.08
B
98-00
Future -Paved parking & roofs
1.29
B
98-00
> 75 % grass cover, Good
4.54
B
61-00
Composite Area & Weighted CN
17.91
88-62
Time of Concentration
TOC Method : SCS TR-55
Sheet Flow Equation :
Tc = (0-007 * ((n * Lf)^0-8)) / ((P^0-5) * (Sf^0-4))
Where :
Tc =
Time of Concentration (hr)
n =
Manning's roughness
Lf =
Flow Length (ft)
P =
2 yr, 24 hr Rainfall (inches)
Sf =
Slope (ft/ft)
Shallow Concentrated Flow Equation :
V = 16-1345 * (Sf^0-5) (unpaved surface)
V = 20-3282 * (Sf^0-5) (paved surface)
V = 15-0 * (Sf^0-5) (grassed waterway surface)
V = 10-0 * (Sf^0-5) (nearly bare & untilled surface)
V = 9-0 * (Sf^0-5) (cultivated straight rows surface)
V = 7-0 * (Sf^0-5) (short grass pasture surface)
V = 5-0 * (Sf^0-5) (woodland surface)
V = 2-5 * (Sf^0-5) (forest w/heavy litter surface)
Tc = (Lf / V) / (3600 sec/hr)
Where
Tc = Time of Concentration (hr)
Lf = Flow Length (ft)
V = Velocity (ft/sec)
Sf = Slope (ft/ft)
Channel Flow Equation:
V = (1-49 * (R^(2/3)) * (Sf^0-5)) / n
R =Aq/Wp
Tc = (Lf / V) / (3600 sec/hr)
Where :
Tc =
Time of Concentration (hr)
Lf =
Flow Length (ft)
R =
Hydraulic Radius (ft)
Aq =
Flow Area (ft)
Wp
= Wetted Perimeter (ft)
V =
Velocity (ft/sec)
Sf =
Slope (ft/ft)
n =
Manning's roughness
User -Defined TOC override (minutes): 5
Subbasin Runoff Results
Total Rainfall (in)------------------------------------------------------------ 6-10
Total Runoff (in)------------------------------------------------------------- 4-79
Peak Runoff (cfs)----------------------------------------------------------- 83-90
Weighted Curve Number----------------------------------------------- 88-62
Time of Concentration (days hh:mm:ss)------------------------ 0 00-05-00

Post -Development 025 - Year Page 7

Post -Development 025 - Year Page 8
Subbasin : SUB-04
5.2
5
4.0
4.6
4.4
4.2
4
3.8
3.6
3.4
3.2
3
2.8
2.6
2.4
ry 2.2
2
1.8
1.6
1.4
1.2
1
0.8
0.6
0.4
0.2
90
85
80
75
70
65
60
55
50
v 45
0
40
35
30
25
20
15
10
5
Rainfall Intensity Graph
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23
Time [hrs]
Runoff Hydrograph
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23
Time [hrs]

Post -Development 025 - Year Page 9

Post -Development 025 - Year
Subbasin : SUB-05
Page 10
Input Data
Area(ac)------------------------------------------------------------------------ 43.54
Peak Rate Factor----------------------------------------------------------- 0.00
Weighted Curve Number----------------------------------------------- 73.00
RainGage ID-----------------------------------------------------------------
Composite Curve Number
Area Soil Curve
Soil/Surface Description (acres) Group Number
43.54 - 73.00
Composite Area & Weighted CN 43.54 73.00
Time of Concentration
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) ------------------
Subbasin Runoff Results
Flowpath
Flowpath
Flowpath
A
B
C
3
0.00
0.00
100
0.00
0.00
4
0.00
0.00
3.50
0.00
0.00
0.13
0.00
0.00
12.36
0.00
0.00
Flowpath
Flowpath
Flowpath
A
B
C
2460
0.00
0.00
2.4
0.00
0.00
Unpaved
Unpaved
Unpaved
2.50
0.00
0.00
16.40
0.00
0.00
Total Rainfall (in)------------------------------------------------------------ 6.10
Total Runoff (in)------------------------------------------------------------- 3.17
Peak Runoff (cfs)----------------------------------------------------------- 94.59
Weighted Curve Number----------------------------------------------- 73.00
Time of Concentration (days hh:mm:ss)------------------------ 0 0028:46

Post -Development 025 - Year Page 11

Post -Development 025 - Year Page 12
Subbasin : SUB-05
5.4
5.2
5
4.8
4.6
4.4
4.2
4
3.8
3.6
3.4
3.2
3
28
2.6
F, 2.4
2.2
2
1.8
1.6
14
1.2
1
0.8
0.6
0.4
0.2
100
95
90
85
80
75
70
65
60
55
v 50
0
45
40
35
30
25
20
15
10
5
Rainfall Intensity Graph
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23
Time [hrs]
Runoff Hydrograph
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23
Time [hrs]

Post -Development 025 - Year Page 13

Post -Development 025 - Year Page 14
Pipe Input
SN Element Length Inlet Inlet Outlet Outlet Total Average Pipe Pipe Pipe Manning's Entrance Exit/Bend Additional Initial Flap
ID Invert Invert Invert Invert Drop Slope Shape Diameteror Width Roughness Losses Losses Losses Flow Gate
Elevation Offset Elevation Offset Height
(ft) (ft) (ft) (ft) (ft) (ft) ( % ) (in) (in) (cfs)
1 Outlet -Pipe 89.00 567.00 7.00 566.64 -0.36 0.36 0.4000 CIRCULAR 36.000 36.000 0.0150 0.5000 0.5000 0.0000 0.00 No

Post -Development 025 - Year Page 15
No. of
Barrels

Post -Development 025 - Year Page 16
Pipe Results
SN Element Peak Time of Design Flow Peak Flow/ Peak Flow Travel Peak Flow Peak Flow Total Time Froude Reported
ID Flow Peak Flow Capacity Design Flow Velocity Time Depth Depth/ Surcharged Number Condition
Occurrence Ratio Total Depth
Ratio
(cfs) (days hh:mm) (cfs) (ft/sec) (min) (ft) (min)
1 Outlet -Pipe 16.53 0 12:36 1.94 8.53 4.15 0.36 1.65 0.55 0.00 > CAPACITY

Post -Development 025 - Year Page 17
Storage Nodes
Storage Node : Pond-04
Input Data
Invert Elevation (ft)--------------------------------------------------------------------
562-50
Max (Rim) Elevation (ft)------------------------------------------------------------
573-50
Max (Rim) Offset (ft)-----------------------------------------------------------------
11-00
Initial Water Elevation (ft)----------------------------------------------------------
567-00
Initial Water Depth (ft)---------------------------------------------------------------
4-50
Ponded Area (ft) -----------------------------------------------------------------------
1-00
Evaporation Loss-----------------------------------------------------------------------
0-00
Outflow Weirs
SIN Element
Weir Flap
Crest
Crest
Length
Weir Total Discharge
ID
Type Gate
Elevation
Offset
Height Coefficient
(ft)
(ft)
(ft)
(ft)
1 Spillway-04
Trapezoidal No
572-75
1025
20-00
0-75 3-33
2 Weir-04
Rectangular No
569-00
6-50
2-00
4-00 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 Bottom
Rectangular No
60-00
60-00
573-00 0-63
2 WQ-Orifice-04 Side
CIRCULAR
No
3-00
567-00 0-61
Output Summary Results
Peak Inflow (cfs)------------------------------------------------------------------------
8324
Peak Lateral Inflow (cfs)------------------------------------------------------------
8324
Peak Outflow (cfs)---------------------------------------------------------------------
16-53
Peak Exfiltration Flow Rate (cfm)----------------------------------------------
0-00
Max HGL Elevation Attained (ft)------------------------------------------------
571-12
Max HGL Depth Attained (ft)-----------------------------------------------------
8-62
Average HGL Elevation Attained (ft)-----------------------------------------
568-88
Average HGL Depth Attained (ft)----------------------------------------------
6-38
Time of Max HGL Occurrence (days hh:mm)---------------------------
0 12-36
Total Exfiltration Volume (1000-ft3)-------------------------------------------
0-000
Total Flooded Volume (ac-in) -
0
Total Time Flooded (min)
0
Total Retention Time (sec) --------------------------------------------------------
0-00

Post -Development 050 - Year Page 1
Project Description
File Name .................................................... 27842.0003 - POST.SPF
Project Options
Flow Units ---------------------------------------------------
CFS
Elevation Type
Elevation
Hydrology Method .
SCS TR-55
Time of Concentration (TOC) Method --------
SCS TR-55
Link Routing Method
Hydrodynamic
Enable Overflow Ponding at Nodes ------------
YES
Skip Steady State Analysis Time Periods ---
NO
Analysis Options
Start Analysis On .
Dec 03, 2020
00:00:00
End Analysis On .
Dec 04, 2020
00:00:00
Start Reporting On .
Dec 03, 2020
00:00:00
Antecedent Dry Days
0
days
Runoff (Dry Weather) Time Step ----------------
0 01:00:00
days hh:mm:ss
Runoff (Wet Weather) Time Step ---------------
0 00:05:00
days hh:mm:ss
Reporting Time Step -----------------------------------
0 00:05:00
days hh:mm:ss
Routing Time Step --------------------------------------
15
seconds
Number of Elements
Qty
Rain Gages
1
Subbasins
2
Nodes
4
Junctions
1
Outfalls
2
Flow Diversions
0
Inlets
0
Storage Nodes
1
Links
5
Channels
0
Pipes
1
Pumps
0
Orifices
2
Weirs
2
Outlets
0
Pollutants
0
Land Uses
0
Rainfall Details
SN Rain Gage Data Data Source Rainfall Rain State County Return Rainfall Rainfall
ID Source ID Type Units Period Depth Distribution
(years) (inches)
1 Time Series TS-050 Intensity inches North Carolina Union 50 6.90 SCS Type III 24-hr

Post -Development 050 - Year Page 2
Subbasin Summary
SN Subbasin Area Peak Rate Weighted
ID Factor Curve
Number
Total Total Total Peak Time of
Rainfall Runoff Runoff Runoff Concentration
Volume
(ac) (in) (in) (ac-in) (cfs) (days hh:mm:ss)
1 SUB-04 17.91 0.00 88.62 6.90 5.57 99.70 96.54 0 00-05-00
2 SUB-05 43.54 0.00 73.00 6.90 3.85 167.59 114.94 0 0028:45

Post -Development 050 - Year Page 3
Node Summary
SN Element
Element
Invert Ground/Rim
Initial Surcharge Ponded
Peak Max HGL
Max
Min
Time of Total
ID
Type
Elevation
(Max)
Water Elevation
Area
Inflow
Elevation Surcharge
Freeboard
Peak Flooded
Elevation Elevation
Attained
Depth
Attained
Flooding Volume
Attained
Occurrence
(ft)
(ft)
(ft) (ft)
(ft')
(cfs)
(ft)
(ft)
(ft) (days hh:mm) (ac-in)
1 CONTROL -STRUCTURE
Junction
567.00
573.00
0.00 0.00
1.00
2095.
56927
0.00
823
0 00:00 0.00
2 Emergency-Outffall
Outffall
560.00
0.00
560.00
3 Out-02
Outffall
560.00
134.76
560.00
4 Pond-04
Storage Node
562.50
573.50
567.00
1.00
95.95
571.62
0.00

Post -Development
Total Time
Flooded
(min)
0.00
0.00
050 - Year
Page 4

Post -Development 050 - Year
Page 5
Link Summary
SN Element Element From To (Outlet) Length Inlet Outlet Average Diameter or Manning's Peak Design Flow Peak Flow/ Peak Flow Peak Flow Peak Flow Total Time Reported
ID Type (Inlet) Node Invert Invert Slope Height Roughness Flow Capacity Design Flow Velocity Depth Depth/ Surcharged Condition
Node Elevation Elevation Ratio Total Depth
Ratio
(ft)
(ft)
(ft) ( % )
(in)
(cfs) (cfs) (ft/sec) (ft) (min)
1 Outlet -Pipe Pipe
Out-02 CONTROL -STRUCTURE 89.00
567.00
566.64 0.4000
36.000
0.0150 2095.1.94 10.81 4.52 1.87 0.62 0.00 > CAPACITY
2 CS -RIM Orifice
Pond-04 CONTROL -STRUCTURE
562.50
567.00
60.000
0.00
3 WQ-Orifice-04 Orifice
Pond-04 CONTROL -STRUCTURE
562.50
567.00
3.000
0.37
4 Spillway-04 Weir
Pond-04 Emergency-Outffall
562.50
560.00
0.00
5 Weir-04 Weir
Pond-04 CONTROL -STRUCTURE
562.50
567.00
2058.

Post -Development 050 - Year
Subbasin Hydrology
Page 6
Subbasin : SUB-04
Input Data
Area(ac)------------------------------------------------------------------------
17-91
Peak Rate Factor-----------------------------------------------------------
0-00
Weighted Curve Number-----------------------------------------------
88-62
Rain Gage ID
Composite Curve Number
Area
Soil
Curve
Soil/Surface Description
(acres)
Group
Number
Paved parking & roofs
12.08
B
98-00
Future -Paved parking & roofs
1.29
B
98-00
> 75 % grass cover, Good
4.54
B
61-00
Composite Area & Weighted CN
17.91
88-62
Time of Concentration
TOC Method : SCS TR-55
Sheet Flow Equation :
Tc = (0-007 * ((n * Lf)^0-8)) / ((P^0-5) * (Sf^0-4))
Where :
Tc =
Time of Concentration (hr)
n =
Manning's roughness
Lf =
Flow Length (ft)
P =
2 yr, 24 hr Rainfall (inches)
Sf =
Slope (ft/ft)
Shallow Concentrated Flow Equation :
V = 16-1345 * (Sf^0-5) (unpaved surface)
V = 20-3282 * (Sf^0-5) (paved surface)
V = 15-0 * (Sf^0-5) (grassed waterway surface)
V = 10-0 * (Sf^0-5) (nearly bare & untilled surface)
V = 9-0 * (Sf^0-5) (cultivated straight rows surface)
V = 7-0 * (Sf^0-5) (short grass pasture surface)
V = 5-0 * (Sf^0-5) (woodland surface)
V = 2-5 * (Sf^0-5) (forest w/heavy litter surface)
Tc = (Lf / V) / (3600 sec/hr)
Where
Tc = Time of Concentration (hr)
Lf = Flow Length (ft)
V = Velocity (ft/sec)
Sf = Slope (ft/ft)
Channel Flow Equation:
V = (1-49 * (R^(2/3)) * (Sf^0-5)) / n
R =Aq/Wp
Tc = (Lf / V) / (3600 sec/hr)
Where :
Tc =
Time of Concentration (hr)
Lf =
Flow Length (ft)
R =
Hydraulic Radius (ft)
Aq =
Flow Area (ft)
Wp
= Wetted Perimeter (ft)
V =
Velocity (ft/sec)
Sf =
Slope (ft/ft)
n =
Manning's roughness
User -Defined TOC override (minutes): 5
Subbasin Runoff Results
Total Rainfall (in)------------------------------------------------------------ 6-90
Total Runoff (in)------------------------------------------------------------- 5-57
Peak Runoff (cfs)----------------------------------------------------------- 96-54
Weighted Curve Number----------------------------------------------- 88-62
Time of Concentration (days hh:mm:ss)------------------------ 0 00-05-00

Post -Development 050 - Year Page 7

Post -Development 050 - Year Page 8
Subbasin : SUB-04
6
5.8
5.6
5.4
5.2
5
4.8
4.6
4.4
4.2
4
3.8
3.6
3.4
3.2
v 3
2.8
� 2.6
2.4
2.2
2
1.8
1.6
1.4
1.2
1
0.8
0.6
04
0.2
105
100
95
90
85
80
75
70
65
60
55
50
45
40
35
30
25
20
15
10
5
Rainfall Intensity Graph
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23
Time [hrs]
Runoff Hydrograph
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23
Time [hrs]

Post -Development 050 - Year Page 9

Post -Development 050 - Year
Subbasin : SUB-05
Page 10
Input Data
Area(ac)------------------------------------------------------------------------ 43.54
Peak Rate Factor----------------------------------------------------------- 0.00
Weighted Curve Number----------------------------------------------- 73.00
RainGage ID-----------------------------------------------------------------
Composite Curve Number
Area Soil Curve
Soil/Surface Description (acres) Group Number
43.54 - 73.00
Composite Area & Weighted CN 43.54 73.00
Time of Concentration
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) ------------------
Subbasin Runoff Results
Flowpath
Flowpath
Flowpath
A
B
C
3
0.00
0.00
100
0.00
0.00
4
0.00
0.00
3.50
0.00
0.00
0.13
0.00
0.00
12.36
0.00
0.00
Flowpath
Flowpath
Flowpath
A
B
C
2460
0.00
0.00
2.4
0.00
0.00
Unpaved
Unpaved
Unpaved
2.50
0.00
0.00
16.40
0.00
0.00
Total Rainfall (in)------------------------------------------------------------ 6.90
Total Runoff (in)------------------------------------------------------------- 3.85
Peak Runoff (cfs)----------------------------------------------------------- 114.94
Weighted Curve Number----------------------------------------------- 73.00
Time of Concentration (days hh:mm:ss)------------------------ 0 0028:46

Post -Development 050 - Year Page 11

Post -Development 050 - Year Page 12
Subbasin : SUB-05
6.2
6
5.8
5.6
5.4
5.2
5
4.8
4.6
4.4
4.2
4
3.8
3.6
3.4
v 3.2
3
2.8
2.6
2.4
2.2
2
1.8
1.6
1.4
1.2
1
0.8
0.6
0.4
0.2
120
115
110
106
100
95
90
85
80
75
70
65
v 60
0
55
50
45
40
35
30
25
20
15
10
5
Rainfall Intensity Graph
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23
Time [hrs]
Runoff Hydrograph
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23
Time [hrs]

Post -Development 050 - Year Page 13

Post -Development 050 - Year Page 14
Pipe Input
SN Element Length Inlet Inlet Outlet Outlet Total Average Pipe Pipe Pipe Manning's Entrance Exit/Bend Additional Initial Flap
ID Invert Invert Invert Invert Drop Slope Shape Diameteror Width Roughness Losses Losses Losses Flow Gate
Elevation Offset Elevation Offset Height
(ft) (ft) (ft) (ft) (ft) (ft) ( % ) (in) (in) (cfs)
1 Outlet -Pipe 89.00 567.00 7.00 566.64 -0.36 0.36 0.4000 CIRCULAR 36.000 36.000 0.0150 0.5000 0.5000 0.0000 0.00 No

Post -Development 050 - Year Page 15
No. of
Barrels

Post -Development 050 - Year Page 16
Pipe Results
SN Element Peak Time of Design Flow Peak Flow/ Peak Flow Travel Peak Flow Peak Flow Total Time Froude Reported
ID Flow Peak Flow Capacity Design Flow Velocity Time Depth Depth/ Surcharged Number Condition
Occurrence Ratio Total Depth
Ratio
(cfs) (days hh:mm) (cfs) (ft/sec) (min) (ft) (min)
1 Outlet -Pipe 2095.0 12:35 1.94 10.81 4.52 0.33 1.87 0.62 0.00 > CAPACITY

Post -Development 050 - Year Page 17
Storage Nodes
Storage Node : Pond-04
Input Data
Invert Elevation (ft)--------------------------------------------------------------------
562-50
Max (Rim) Elevation (ft)------------------------------------------------------------
573-50
Max (Rim) Offset (ft)-----------------------------------------------------------------
11-00
Initial Water Elevation (ft)----------------------------------------------------------
567-00
Initial Water Depth (ft)---------------------------------------------------------------
4-50
Ponded Area (ft) -----------------------------------------------------------------------
1-00
Evaporation Loss-----------------------------------------------------------------------
0-00
Outflow Weirs
SIN Element
Weir Flap
Crest
Crest
Length
Weir Total Discharge
ID
Type Gate
Elevation
Offset
Height Coefficient
(ft)
(ft)
(ft)
(ft)
1 Spillway-04
Trapezoidal No
572-75
1025
20-00
0-75 3-33
2 Weir-04
Rectangular No
569-00
6-50
2-00
4-00 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 Bottom
Rectangular No
60-00
60-00
573-00 0-63
2 WQ-Orifice-04 Side
CIRCULAR
No
3-00
567-00 0-61
Output Summary Results
Peak Inflow (cfs)------------------------------------------------------------------------
95-95
Peak Lateral Inflow (cfs)------------------------------------------------------------
95-95
Peak Outflow (cfs)---------------------------------------------------------------------
20-95
Peak Exfiltration Flow Rate (cfm)----------------------------------------------
0-00
Max HGL Elevation Attained (ft)------------------------------------------------
571-62
Max HGL Depth Attained (ft)-----------------------------------------------------
9-12
Average HGL Elevation Attained (ft)-----------------------------------------
569-05
Average HGL Depth Attained (ft)----------------------------------------------
6-55
Time of Max HGL Occurrence (days hh:mm)---------------------------
0 12-34
Total Exfiltration Volume (1000-ft3)-------------------------------------------
0-000
Total Flooded Volume (ac-in) -
0
Total Time Flooded (min)
0
Total Retention Time (sec) --------------------------------------------------------
0-00

Post -Development 100 - Year Page 1
Project Description
File Name .................................................... 27842.0003 - POST.SPF
Project Options
Flow Units ---------------------------------------------------
CFS
Elevation Type
Elevation
Hydrology Method .
SCS TR-55
Time of Concentration (TOC) Method --------
SCS TR-55
Link Routing Method
Hydrodynamic
Enable Overflow Ponding at Nodes ------------
YES
Skip Steady State Analysis Time Periods ---
NO
Analysis Options
Start Analysis On .
Dec 03, 2020
00:00:00
End Analysis On .
Dec 04, 2020
00:00:00
Start Reporting On .
Dec 03, 2020
00:00:00
Antecedent Dry Days
0
days
Runoff (Dry Weather) Time Step ----------------
0 01:00:00
days hh:mm:ss
Runoff (Wet Weather) Time Step ---------------
0 00:05:00
days hh:mm:ss
Reporting Time Step -----------------------------------
0 00:05:00
days hh:mm:ss
Routing Time Step --------------------------------------
15
seconds
Number of Elements
Qty
Rain Gages
1
Subbasins
2
Nodes
4
Junctions
1
Outfalls
2
Flow Diversions
0
Inlets
0
Storage Nodes
1
Links
5
Channels
0
Pipes
1
Pumps
0
Orifices
2
Weirs
2
Outlets
0
Pollutants
0
Land Uses
0
Rainfall Details
SN Rain Gage Data Data Source Rainfall Rain State County Return Rainfall Rainfall
ID Source ID Type Units Period Depth Distribution
(years) (inches)
1 Time Series TS-100 Intensity inches North Carolina Union 100 7.50 SCS Type III 24-hr

Post -Development 100 - Year Page 2
Subbasin Summary
SN Subbasin Area Peak Rate Weighted
ID Factor Curve
Number
Total Total Total Peak Time of
Rainfall Runoff Runoff Runoff Concentration
Volume
(ac) (in) (in) (ac-in) (cfs) (days hh:mm:ss)
1 SUB-04 17.91 0.00 88.62 7.50 6.15 110.18 106.00 0 00-05-00
2 SUB-05 43.54 0.00 73.00 7.50 4.37 19027 130.49 0 0028:45

Post -Development 100 - Year Page 3
Node Summary
SN Element
Element
Invert Ground/Rim
Initial Surcharge Ponded
Peak Max HGL
Max
Min
Time of Total
ID
Type
Elevation
(Max)
Water Elevation
Area
Inflow
Elevation Surcharge
Freeboard
Peak Flooded
Elevation Elevation
Attained
Depth
Attained
Flooding Volume
Attained
Occurrence
(ft)
(ft)
(ft) (ft)
(ft')
(cfs)
(ft)
(ft)
(ft) (days hh:mm) (ac-in)
1 CONTROL -STRUCTURE
Junction
567.00
573.00
0.00 0.00
1.00
23.98
569.45
0.00
8.05
0 00:00 0.00
2 Emergency-Outffall
Outffall
560.00
0.00
560.00
3 Out-02
Outffall
560.00
153.43
560.00
4 Pond-04
Storage Node
562.50
573.50
567.00
1.00
105.41
571.99
0.00

Post -Development
Total Time
Flooded
(min)
0.00
0.00
100 - Year
Page 4

Post -Development 100 - Year
Page 5
Link Summary
SN Element Element From To (Outlet) Length Inlet Outlet Average Diameter or Manning's Peak Design Flow Peak Flow/ Peak Flow Peak Flow Peak Flow Total Time Reported
ID Type (Inlet) Node Invert Invert Slope Height Roughness Flow Capacity Design Flow Velocity Depth Depth/ Surcharged Condition
Node Elevation Elevation Ratio Total Depth
Ratio
(ft)
(ft)
(ft) ( % )
(in)
(cfs) (cfs) (ft/sec) (ft) (min)
1 Outlet -Pipe Pipe
Out-02 CONTROL -STRUCTURE 89.00
567.00
566.64 0.4000
36.000
0.0150 23.98 1.94 12.37 4.75 2.01 0.67 0.00 > CAPACITY
2 CS -RIM Orifice
Pond-04 CONTROL -STRUCTURE
562.50
567.00
60.000
0.00
3 WQ-Orifice-04 Orifice
Pond-04 CONTROL -STRUCTURE
562.50
567.00
3.000
0.39
4 Spillway-04 Weir
Pond-04 Emergency-Outffall
562.50
560.00
0.00
5 Weir-04 Weir
Pond-04 CONTROL -STRUCTURE
562.50
567.00
23.59

Post -Development 100 - Year
Subbasin Hydrology
Page 6
Subbasin : SUB-04
Input Data
Area(ac)------------------------------------------------------------------------
17-91
Peak Rate Factor-----------------------------------------------------------
0-00
Weighted Curve Number-----------------------------------------------
88-62
Rain Gage ID
Composite Curve Number
Area
Soil
Curve
Soil/Surface Description
(acres)
Group
Number
Paved parking & roofs
12.08
B
98-00
Future -Paved parking & roofs
1.29
B
98-00
> 75 % grass cover, Good
4.54
B
61-00
Composite Area & Weighted CN
17.91
88-62
Time of Concentration
TOC Method : SCS TR-55
Sheet Flow Equation :
Tc = (0-007 * ((n * Lf)^0-8)) / ((P^0-5) * (Sf^0-4))
Where :
Tc =
Time of Concentration (hr)
n =
Manning's roughness
Lf =
Flow Length (ft)
P =
2 yr, 24 hr Rainfall (inches)
Sf =
Slope (ft/ft)
Shallow Concentrated Flow Equation :
V = 16-1345 * (Sf^0-5) (unpaved surface)
V = 20-3282 * (Sf^0-5) (paved surface)
V = 15-0 * (Sf^0-5) (grassed waterway surface)
V = 10-0 * (Sf^0-5) (nearly bare & untilled surface)
V = 9-0 * (Sf^0-5) (cultivated straight rows surface)
V = 7-0 * (Sf^0-5) (short grass pasture surface)
V = 5-0 * (Sf^0-5) (woodland surface)
V = 2-5 * (Sf^0-5) (forest w/heavy litter surface)
Tc = (Lf / V) / (3600 sec/hr)
Where
Tc = Time of Concentration (hr)
Lf = Flow Length (ft)
V = Velocity (ft/sec)
Sf = Slope (ft/ft)
Channel Flow Equation:
V = (1-49 * (R^(2/3)) * (Sf^0-5)) / n
R =Aq/Wp
Tc = (Lf / V) / (3600 sec/hr)
Where :
Tc =
Time of Concentration (hr)
Lf =
Flow Length (ft)
R =
Hydraulic Radius (ft)
Aq =
Flow Area (ft)
Wp
= Wetted Perimeter (ft)
V =
Velocity (ft/sec)
Sf =
Slope (ft/ft)
n =
Manning's roughness
User -Defined TOC override (minutes): 5
Subbasin Runoff Results
Total Rainfall (in)------------------------------------------------------------ 7-50
Total Runoff (in)------------------------------------------------------------- 6-15
Peak Runoff (cfs)----------------------------------------------------------- 106-00
Weighted Curve Number----------------------------------------------- 88-62
Time of Concentration (days hh:mm:ss)------------------------ 0 00-05-00

Post -Development 100 - Year Page 7

Post -Development 100 - Year Page 8
Subbasin : SUB-04
6.5
6
5.5
5
4.5
4
E 3.5
3
2.5
2
1.5
0.5
Rainfall Intensity Graph
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23
Time [hrs]
Runoff Hydrograph
115
110
105
100
95
90
85
80
75
70
n 65
-- 60
0 55
50
45
40
35
30
25
20
15
10
5
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23
Time [hrs]

Post -Development 100 - Year Page 9

Post -Development 100 - Year
Subbasin : SUB-05
Page 10
Input Data
Area(ac)------------------------------------------------------------------------ 43.54
Peak Rate Factor----------------------------------------------------------- 0.00
Weighted Curve Number----------------------------------------------- 73.00
RainGage ID-----------------------------------------------------------------
Composite Curve Number
Area Soil Curve
Soil/Surface Description (acres) Group Number
43.54 - 73.00
Composite Area & Weighted CN 43.54 73.00
Time of Concentration
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) ------------------
Subbasin Runoff Results
Flowpath
Flowpath
Flowpath
A
B
C
3
0.00
0.00
100
0.00
0.00
4
0.00
0.00
3.50
0.00
0.00
0.13
0.00
0.00
12.36
0.00
0.00
Flowpath
Flowpath
Flowpath
A
B
C
2460
0.00
0.00
2.4
0.00
0.00
Unpaved
Unpaved
Unpaved
2.50
0.00
0.00
16.40
0.00
0.00
Total Rainfall (in)------------------------------------------------------------ 7.50
Total Runoff (in)------------------------------------------------------------- 4.37
Peak Runoff (cfs)----------------------------------------------------------- 130.49
Weighted Curve Number----------------------------------------------- 73.00
Time of Concentration (days hh:mm:ss)------------------------ 0 0028:46

Post -Development 100 - Year Page 11

Post -Development 100 - Year Page 12
Subbasin : SUB-05
7
6.6
6
5.5
5
4.5
4
3.5
3
2.6
2
1.5
0.5
140
135
130
125
120
116
110
105
100
95
90
85
80
75
v 70
0
65
60
55
50
45
40
35
30
25
20
15
10
5
Rainfall Intensity Graph
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23
Time [hrs]
Runoff Hydrograph
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23
Time [hrs]

Post -Development 100 - Year Page 13

Post -Development 100 - Year Page 14
Pipe Input
SN Element Length Inlet Inlet Outlet Outlet Total Average Pipe Pipe Pipe Manning's Entrance Exit/Bend Additional Initial Flap
ID Invert Invert Invert Invert Drop Slope Shape Diameteror Width Roughness Losses Losses Losses Flow Gate
Elevation Offset Elevation Offset Height
(ft) (ft) (ft) (ft) (ft) (ft) ( % ) (in) (in) (cfs)
1 Outlet -Pipe 89.00 567.00 7.00 566.64 -0.36 0.36 0.4000 CIRCULAR 36.000 36.000 0.0150 0.5000 0.5000 0.0000 0.00 No

Post -Development 100 - Year Page 15
No. of
Barrels

Post -Development 100 - Year Page 16
Pipe Results
SN Element Peak Time of Design Flow Peak Flow/ Peak Flow Travel Peak Flow
Peak Flow Total Time Froude Reported
ID Flow Peak Flow Capacity Design Flow Velocity Time Depth
Depth/ Surcharged Number Condition
Occurrence Ratio
Total Depth
Ratio
(cfs) (days hh:mm) (cfs) (ft/sec) (min) (ft)
(min)
1 Outlet -Pipe 23.98 0 12:34 1.94 12.37 4.75 0.31 2.01
0.67 0.00 > CAPACITY

Post -Development 100 - Year Page 17
Storage Nodes
Storage Node : Pond-04
Input Data
Invert Elevation (ft)--------------------------------------------------------------------
562-50
Max (Rim) Elevation (ft)------------------------------------------------------------
573-50
Max (Rim) Offset (ft)-----------------------------------------------------------------
11-00
Initial Water Elevation (ft)----------------------------------------------------------
567-00
Initial Water Depth (ft)---------------------------------------------------------------
4-50
Ponded Area (ft) -----------------------------------------------------------------------
1-00
Evaporation Loss-----------------------------------------------------------------------
0-00
Outflow Weirs
SIN Element
Weir Flap
Crest
Crest
Length
Weir Total Discharge
ID
Type Gate
Elevation
Offset
Height Coefficient
(ft)
(ft)
(ft)
(ft)
1 Spillway-04
Trapezoidal No
572-75
1025
20-00
0-75 3-33
2 Weir-04
Rectangular No
569-00
6-50
2-00
4-00 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 Bottom
Rectangular No
60-00
60-00
573-00 0-63
2 WQ-Orifice-04 Side
CIRCULAR
No
3-00
567-00 0-61
Output Summary Results
Peak Inflow (cfs)------------------------------------------------------------------------
105-41
Peak Lateral Inflow (cfs)------------------------------------------------------------
105-41
Peak Outflow (cfs)---------------------------------------------------------------------
23-98
Peak Exfiltration Flow Rate (cfm)----------------------------------------------
0-00
Max HGL Elevation Attained (ft)------------------------------------------------
571-99
Max HGL Depth Attained (ft)-----------------------------------------------------
9-49
Average HGL Elevation Attained (ft)-----------------------------------------
569-18
Average HGL Depth Attained (ft)----------------------------------------------
6-68
Time of Max HGL Occurrence (days hh:mm)---------------------------
0 12-34
Total Exfiltration Volume (1000-ft3)-------------------------------------------
0-000
Total Flooded Volume (ac-in) -
0
Total Time Flooded (min)
0
Total Retention Time (sec) --------------------------------------------------------
0-00

25-YR
CAPACITY

H EC-22
Energy Grade Line Computations
Struct.
Q
EGLo
HGLo
Total Pipe
EGLi
HGLi
Ea
EGLa
Surface Elev.
ID
(cfs)
(ft)
(ft)
Loss
(ft)
(ft)
(ft)
(ft)
(ft)
(ft)
3 570.22
570.22
1
568.66
1
49.2
570.46
570.221
0.14
570.60
570.36
5.9
570.73
584.43
12
38.0
570.83
570.59
0.21
571.04
570.80
5.6
571.15
584.99
13
32.7
571.23
571.05
0.03
571.26
571.08
5.7
571.41
585.35
187
7.0
573.47
572.96
1.19
574.65
574.14
2.1
574.94
578.35
188
3.1
574.98
574.88
0.25
575.23
575.131
1.3
575.321
579.80
14
26.01
571.50
571.29
0.19
571.69
571.48
5.4
571.76
582.76
31
1.1
571.76
571.75
571.76
571.75
4.9
571.77
582.76
14
20.1
571.81
571.68
0.13
571.94
571.81
4.9
571.97
579.82
15
18.8
572.06
571.83
0.44
572.50
572.27
4.5
572.64
576.04
18
7.2
572.67
572.59
0.16
572.83
572.75
3.9
572.85
580.44
19
7.1
575.10
574.46
575.37
574.74
2.0
575.86
582.00
19
6.51
575.95
575.741
0.18
576.12
575.91
2.0
576.26
581.65
21
5.3
576.32
576.18
0.31
576.62
576.48
2.1
577.59
580.25
22
3.6
577.62
577.55
0.04
577.66
577.59
1.8
577.69
580.30
38
7.0
572.73
572.49
0.67
573.40
573.16
4.0
573.51
574.47
38
1.3
573.51
573.50
0.02
573.53
573.52
3.0
573.54
577.96
17
3.6
572.66
572.60
0.03
572.70
572.631
4.3
572.741
576.04
35
1.21
571.97
571.971
571.98
571.97
4.3
571.98
579.82
34
5.0
571.80
571.68
0.06
571.87
571.75
5.0
571.94
581.11
32
4.9
571.99
571.87
0.22
572.20
572.08
4.4
572.32
579.38
32
2.5
572.33
572.30
0.02
572.35
572.32
4.1
572.38
579.38
27
4.2
576.93
576.47
578.53
578.07
1.1
578.53
587.95
28
4.0
578.59
578.45
579.23
578.751
1.2
579.261
587.09
29
3.91
579.31
579.201
580.21
579.74
1.1
580.25
586.01
30
1.4
580.26
580.24
580.26
579.99
0.9
580.26
586.01
2
10.5
570.74
570.72
0.01
570.75
570.74
4.9
570.76
581.91
3
9.9
570.77
570.74
0.03
570.80
570.77
3.6
570.81
578.90
4
8.8
570.82
570.80
0.02
570.84
570.81
2.9
570.85
577.01
5
8.9
570.87
570.82
0.03
570.90
570.851
2.3
570.921
575.91
6
6.21
570.93
570.90
570.93
570.40
1.7
570.93
577.97
7
5.5
570.95
570.91
571.34
570.84
1.1
571.34
577.32
8
5.6
571.38
571.27
572.82
572.32
1.1
572.82
578.76
9
4.6
572.86
572.76
574.29
573.82
1.1
574.29
579.95
10
3.4
574.33
574.23
575.11
574.70
1.0
575.12
578.93
11
1.1
575.12
575.11
575.73
575.51
0.6
575.73
579.97
39
556.64
556.64
571.30
124
23.4
568.92
567.79
570.65
569.52
2.3
570.65
582.99
125
16.6
570.69
570.59
570.69
569.76
2.0
570.69
582.93
130
14.9
570.74
570.61
571.31
570.41
1.9
571.31
579.55
43
10.4
571.38
571.21
572.49
571.761
1.5
572.491
580.79
44
6.41
573.20
572.62
575.03
574.46
1.2
575.03
582.60
143
3.2
575.65
575.27
577.46
577.08
0.9
577.46
584.50
50
2.1
575.53
575.20
577.29
576.95
0.8
577.29
585.17
49
5.8
575.25
574.89
576.06
575.70
1.0
576.06
584.36
207
3.5
576.08
576.03
576.26
575.98
0.8
576.26
585.07
47
2.3
576.28
576.24
576.89
576.67
0.7
576.89
586.43
147
0.91
576.90
576.89
576.90
576.77
0.5
576.90
586.45
153
1.8
576.61
576.30
576.97
576.66
0.7
576.97
584.64
159
11.8
568.33
567.34
569.05
568.07
1.7
569.05
580.64
52
9.1
569.07
569.02
570.44
569.59
1.5
570.44
581.51
53
5.9
570.46
570.41
572.30
571.60
1.3
572.30
584.28
165
3.5
572.31
572.28
574.06
573.551
0.9
574.061
590.70
55
0.51
574.06
574.06
575.56
575.39
0.4
575.56
597.77
56
0.2
575.56
575.56
576.38
576.28
0.2
576.38
599.60
177
0.1
576.38
576.38
576.87
576.80
0.2
576.87
599.73
10
22.0
583.40
583.07
583.80
583.46
0.8
583.80
591.55
105
1.5
576.28
576.00
576.73
576.44
0.7
576.73
585.15
103
2.0
575.171
574.84
1 575.531
575.201
0.81
575.531
581.52
F4 THOMAS s HUTTON
Z: 127842127842.00031 Engineering I Calculations and Reports IStorm Waterl HEC-22127842.0003 - HEC-22 Reporting

H EC-22
Energy Grade Line Computations
Struct.
ID
Q
(cfs)
EGLo
(ft)
HGLo
(ft)
Total Pipe
Loss
(ft)
EGLi
(ft)
HGLi
(ft)
Ea
(ft)
EGLa
(ft)
Surface Elev.
(ft)
159 1.0 574.39
574.16
574.75
574.521
0.61 574.75
580.64
109
573.04
573.04
569.91
112
67.6
573.32
573.04
0.09
573.41
573.13
8.4
573.65
589.42
114
67.4
573.76
573.48
0.18
573.94
573.66
8.2
574.18
588.84
134
1.6
579.63
579.15
583.43
582.95
0.8
583.43
587.04
115
66.41
574.36
573.92
0.32
574.67
574.241
8.3
575.04
589.64
137
1.1
579.62
579.22
582.22
581.82
0.7
582.22
590.83
138
0.5
582.22
582.22
582.65
582.43
0.4
582.65
590.84
115
64.6
575.20
574.79
0.21
575.42
575.01
8.3
575.65
588.64
118
31.8
575.69
575.59
0.11
575.81
575.71
7.4
575.84
586.44
119
27.0
575.89
575.771
0.08
575.97
575.85
7.0
576.02
585.34
121
21.31
576.05
575.97
0.04
576.09
576.01
6.6
576.12
584.46
69
15.2
576.18
576.03
0.16
576.35
576.20
3.6
576.42
583.34
126
10.3
576.45
576.38
0.11
576.56
576.49
2.1
576.59
581.75
127
8.7
576.63
576.51
577.55
576.86
1.6
577.59
580.64
128
0.7
577.59
577.59
577.59
577.49
0.5
577.59
582.38
133
0.2
577.59
577.59
0.18
577.77
577.73
0.6
577.81
582.38
186
4.91
577.64
577.52
0.08
577.72
577.60
1.6
577.79
580.64
182
4.0
576.43
576.40
0.01
576.44
576.42
3.4
576.45
583.34
103
3.7
576.46
576.44
0.04
576.50
576.48
2.7
576.51
583.08
103
0.6
576.51
576.51
576.51
576.51
2.4
576.52
581.12
103
2.5
576.52
576.51
0.02
576.54
576.53
2.0
576.54
579.83
105
1.0
576.54
576.541
576.54
576.421
1.4
576.54
581.39
108
6.61
576.13
576.10
0.04
576.17
576.14
5.9
576.20
583.71
109
6.7
576.21
576.18
0.03
576.24
576.21
5.3
576.25
582.89
208
5.9
576.28
576.22
0.08
576.35
576.30
4.9
576.38
581.12
110
6.0
576.40
576.34
0.08
576.48
576.42
4.4
576.50
580.13
209
4.5
576.51
576.48
0.05
576.56
576.53
3.9
576.57
578.77
111
4.5
576.58
576.551
0.04
576.62
576.591
3.4
576.63
577.72
112
2.51
576.64
576.61
0.07
576.71
576.68
2.9
576.73
579.77
113
1.6
576.74
576.71
0.131
576.87
576.84
2.1
576.89
581.81
176
6.0
576.04
575.98
0.03
576.06
576.01
6.7
576.10
585.34
174
5.4
576.16
576.02
0.09
576.26
576.11
6.6
576.35
584.42
174
5.2
576.41
576.27
0.22
576.63
576.49
6.0
576.69
583.34
178
1.1
576.70
576.69
0.01
576.71
576.691
1.1
576.72
583.33
100
1 3.41
576.72
576.66
0.21
576.93
576.87
4.3
576.98
580.93
100
1.6
576.98
576.97
0.01
576.99
576.98
3.9
577.00
581.29
171
4.3
575.92
575.73
0.16
576.08
575.89
1.6
576.17
586.43
172
3.6
576.23
576.09
578.95
578.34
1.2
578.95
581.32
144
34.3
575.98
575.17
577.03
575.63
3.1
577.22
588.64
144
32.1
577.35
577.03
0.06
577.42
577.101
3.2
577.59
588.48
142
31.71
577.71
577.40
0.06
577.77
577.46
3.4
578.04
588.48
140
30.5
578.28
577.68
0.98
579.25
578.65
4.0
580.39
590.65
146
14.5
580.44
580.31
0.20
580.64
580.51
2.7
580.75
588.50
82
13.3
580.80
580.68
0.03
580.83
580.71
2.4
580.89
588.50
84
13.2
581.00
580.72
0.09
581.09
580.82
2.4
581.26
589.05
155
11.8
581.35
581.13
0.08
581.42
581.20
2.4
581.61
589.05
156
10.61
581.68
581.50
0.21
581.89
581.71
1.9
582.05
590.22
87
9.4
582.23
581.79
1.10
583.33
582.89
2.5
583.58
591.73
88
6.3
583.66
583.46
584.58
583.83
1.6
584.65
593.44
160
3.6
584.68
584.61
585.62
585.17
1.1
585.62
595.15
163
0.8
585.62
585.62
586.55
586.35
0.5
586.55
596.86
91
0.4
586.56
586.55
586.68
586.55
0.3
586.68
596.84
168
1.41
585.63
585.61
585.63
585.36
0.8
585.63
595.13
167
1.4
584.66
584.65
0.01
584.66
584.65
1.3
584.67
593.42
92
1.9
583.59
583.57
0.01
583.60
583.58
2.3
583.62
591.60
201
16.6
580.56
580.13
0.21
580.77
580.34
3.8
581.00
590.44
202
16.4
581.17
580.75
0.41
581.59
581.17
3.21
.80
588.31
203
11.8
581.88
581.66
584.56
583.24
2.2
584.56
590.26
F4 THOMAS s HUTTON
Z: 127842127842.00031 Engineering I Calculations and Reports IStorm Waterl HEC-22127842.0003 - HEC-22 Reporting

H EC-22
Energy Grade Line Computations
Struct.
ID
Q
(cfs)
EGLo
(ft)
HGLo
(ft)
Total Pipe
Loss
(ft)
EGLi
(ft)
HGLi
(ft)
Ea
(ft)
EGLa
(ft)
Surface Elev.
(ft)
204 9.0 584.61
584.48
587.19
586.05
1.9
587.19
591.96
205
1 6.11
587.26
587.08
589.77
588.82
1.61
589.77
593.68
206
1 3.21
589.81
589.70
592.161
591.47
1.21
592.16
595.39
F4 THOMAS s HUTTON
Z: 127842127842.00031 Engineering I Calculations and Reports IStorm Waterl HEC-22127842.0003 - HEC-22 Reporting

H EC-22
Storm Drain Computations
Z��
Length
(ft)
Drainage
Area
(ac)
Runoff
Coeff "C"
Tc
(min)
I
Manning's
n
Rain "I"
(in/hr)
Runoff
"Q..
(cfs)
Total Q
(cfs)
Pipe Dia.
(in)
Velocity
Design
(ft/s)
Invert Elevation
Slope
I
U/S
D/S
1
3
1 122
0.44
0.55
5
0.013
7.48
49.2
49.2
48
8.0
564.85
564.24
0.50%
12
1
146
0.32
0.55
5
0.013
7.69
38.0
38.0
42
7.5
565.58
564.85
0.50%
13
12
33
0.09
0.55
5
0.013
7.71
32.7
32.7
42
7.2
565.75
565.58
0.50%
187
13
119
0.88
0.55
5
0.013
8.17
7.0
7.0
15
5.7
572.89
571.71
1.00%
188
187
111
0.67
0.55
5
0.013
8.25
3.1
3.1
15
5.2
574.00
572.89
1.00%
14
13
127
0.07
0.55
5
0.013
7.781
26.0
26.0
36
6.8
566.38
565.75
0.50%
31
14
24
0.24
0.55
5
0.013
8.25
1.1
1.1
18
3.8
566.91
566.67
1.00%
15
14
145
0.10
0.55
5
0.013
7.86
20.1
20.1
36
6.4
567.10
566.38
0.50%
17
15
207
0.30
0.55
5
0.013
7.99
18.8
18.8
30
6.3
568.14
567.10
0.50%
18
17
158
0.03
0.55
5
0.013
8.11
7.2
7.2
24
5.0
568.93
568.14
0.50%
19
18
28
0.14
0.55
5
0.013
8.13
7.1
7.1
18
6.4
573.84
573.56
1.00%
20
19
46
0.27
0.55
5
0.013
8.15
6.5
6.5
18
6.3
574.30
573.84
1.00%
21
20
120
0.37
0.55
5
0.013
8.23
5.3
5.3
18
6.0
575.50
574.30
1.00%
22
21
35
0.79
0.55
5
0.013
8.25
3.6
3.6
18
5.4
575.85
575.50
1.00%
38
17
152
1.27
0.55
5
0.013
8.09
7.0
7.0
18
5.5
569.50
568.44
0.70%
37
38
155
0.28
0.55
5
0.013
8.25
1.3
1.3
18
3.6
570.58
569.50
0.70%
36
17
28
0.80
0.55
5
0.013
8.25
3.6
3.6
18
5.4
568.42
568.14
1.00%
35
15
28
0.26
0.55
5
0.013
8.25
1.2
1.2
18
3.9
567.68
567.40
1.00%
34
14
29
0.03
0.55
5
0.013
8.17
5.0
5.0
18
5.9
566.96
566.67
1.00%
32
34
101
0.53
0.55
5
0.013
8.23
4.9
4.9
18
5.8
567.96
566.96
1.00%
33
32
28
0.54
0.55
5
0.013
8.25
2.5
2.5
18
4.9
568.24
567.96
1.00%
27
12
160
0.04
0.55
5
0.013
8.12
4.2
4.2
24
5.5
577.49
575.89
1.00%
28
27
62
0.03
0.55
5
0.013
8.16
4.0
4.0
18
5.5
578.11
577.49
1.00%
29
28
100
0.55
0.55
5
0.013
8.23
3.9
3.9
18
5.5
579.11
578.11
1.00%
30
29
28
0.30
0.55
5
0.013
8.25
1.4
1.4
15
4.2
579.39
579.11
1.00%
2
1
111
0.19
0.55
5
0.013
7.54
10.5
10.5
42
6.5
565.86
564.86
0.91%
3
2
148
0.25
0.55
5
0.013
7.63
9.9
9.9
36
6.5
567.20
565.86
0.91%
4
3
88
5
0.013
7.68
8.8
8.8
36
6.3
568.00
567.20
0.91%
5
4
70
0.63
0.55
5
0.013
7.72
8.9
8.9
30
6.4
568.63
568.00
0.91%
6
5
70
0.17
0.55
5
0.013
7.77
6.2
6.2
30
5.8
569.27
568.63
0.91%
7
6
104
5
0.013
7.83
5.5
5.5
30
5.6
570.21
569.27
0.91%
8
7
163
0.24
0.55
5
0.013
7.94
5.6
5.6
30
5.7
571.68
570.21
0.91%
9
8
167
0.29
0.55
5
0.013
8.06
4.6
4.6
24
5.5
573.19
571.68
0.91%
10
9
100
0.51
0.55
5
0.013
8.13
3.4
3.4
18
5.1
574.10
573.19
0.91%
11
10
118
0.24
0.55
5
0.013
8.25
1.1
1.1
18
3.7
575.17
574.10
0.91%
124
39
173
0.27
0.55
5
0.013
7.89
23.4
23.4
42
8.5
568.37
566.64
1.00%
125
124
29
0.38
0.55
5
0.013
7.91
16.6
16.6
42
7.7
568.66
568.37
1.00%
130
125
78
0.60
0.55
5
0.013
7.95
14.9
14.9
36
7.6
569.44
568.66
1.00%
43
130
102
0.92
0.55
5
0.013
8.00
10.4
10.4
36
6.9
570.961
569.94
1.00%
44
43
184
0.72
0.55
5
0.013
8.12
6.4
6.4
30
6.1
573.80
571.96
1.00%
143
44
182
0.69
0.55
5
0.013
8.25
3.2
3.2
30
5.0
576.61
574.80
1.00%
50
130
176
0.46
0.55
5
0.013
8.25
2.1
2.1
18
4.6
576.50
574.74
1.00%
49
124
136
0.12
0.55
5
0.013
8.02
5.8
5.8
36
4.8
575.02
574.21
0.60%
207
49
67
0.27
0.55
5
0.013
8.08
3.5
3.5
30
4.3
575.42
575.02
0.60%
47
207
132
0.32
0.55
5
0.013
8.22
2.3
2.3
30
3.8
576.21
575.42
0.60%
147
47
28
0.19
0.55
5
0.013
8.25
0.9
0.9
30
2.8
576.38
576.21
0.60%
153
49
36
0.40
0.55
5
0.013
8.25
1.8
1.8
18
4.5
576.24
575.88
1.00%
159
39
48
0.42
0.55
5
0.013
7.71
11.8
11.8
48
8.0
567.36
566.64
1.50%
52
159
107
0.34
0.55
5
0.013
7.77
9.1
9.1
48
7.4
568.97
567.36
1.50%
53
52
139
0.24
0.55
5
0.013
7.85
5.9
5.9
36
6.7
571.05
568.97
1.50%
165
53
139
0.24
0.55
5
0.013
7.94
3.5
3.5
36
5.7
573.13
571.05
1.50%
55
165
139
0.06
0.55
5
0.013
8.10
0.5
0.5
30
3.3
575.22
573.13
1.50%
56
55
63
0.03
0.55
5
0.013
8.19
0.2
0.2
30
2.6
576.15
575.22
1.50%
177
56
37
0.03
0.55
5
0.013
8.25
0.1
0.1
24
2.2
576.71
576.15
1.50%
107
165
40
0.44
0.55
5
0.013
8.25
2.0
2.0
15
4.6
582.99
582.59
1.00%
105
53
45
0.33
0.55
5
0.013
8.25
1.5
1.5
15
4.3
576.03
575.58
1.00%
103
52
36
0.43
0.55
5
0.013
8.25
2.0
2.0
15
4.6
574.73
574.37
1.00%
101
159
36
0.23
0.55
5
0.013
8.25
1.0
1.0
15
3.9
574.18
573.82
1.00%
112
109
771
0.241
0.551
51
0.013
6.89
67.6
67.6
54
8.7
565.25
564.87
0.50%
114
112
1561
0.081
0.551
51
0.013
6.96
67.4
67.4
54
8.7
566.03
565.25
0.50%
4 THOMAS 6 HUTTON
Z: �27842 �27842.0003 �Engineering� Calculations and Reports�Storm Water�HEC-22�27842.0003 - HEC-22 Reporting

H EC-22
Storm Drain Computations
Structure ID
Length
(ft)
Drainage
Area
(ac)
Runoff
Coeff "C"
Tc
(min)
I
Manning's
n
Rain "I"
(in/hr)
Runoff
"Q..
(cfs)
Total Q
(cfs)
Pipe Dia.
(in)
Velocity
Design
(ft/s)
Invert Elevation
Slope
From
To
I
U/S
D/S
134
114
190
0.34
0.551
51 0.013
8.25
1.6
1.6
15
5.6
582.60
578.80
2.00%
115
114
150
0.30
0.55
5
0.013
7.02
66.4
66.4
48
8.6
566.78
566.03
0.50%
137
115
130
0.15
0.55
5
0.013
8.22
1.1
1.1
15
5.1
581.52
578.93
2.00%
138
137
36
0.10
0.55
5
0.013
8.25
0.5
0.5
18
3.8
582.25
581.52
2.00%
118
115
106
0.26
0.55
5
0.013
7.07
64.6
64.6
48
8.6
567.31
566.78
0.50%
119
118
234
0.32
0.55
5
0.013
7.191
31.8
31.8
48
7.21
568.48
567.31
0.50%
121
119
116
0.10
0.55
5
0.013
7.26
27.0
27.0
42
6.9
569.06
568.48
0.50%
69
121
94
0.08
0.55
5
0.013
7.31
21.3
21.3
42
6.5
569.53
569.06
0.50%
126
69
119
0.27
0.55
5
0.013
7.69
15.2
15.2
30
11.2
572.83
569.53
2.78%
127
126
175
0.38
0.55
5
0.013
7.79
10.3
10.3
30
6.9
574.53
572.83
0.97%
128
127
150
0.77
0.55
5
0.013
7.88
8.7
8.7
24
6.7
575.99
574.53
0.97%
131
128
213
0.12
0.55
5
0.013
8.19
0.7
0.7
24
2.6
577.05
575.99
0.50%
133
131
36
0.04
0.55
5
0.013
8.25
0.2
0.2
18
1.8
577.23
577.05
0.50%
186
128
36
1.06
0.55
5
0.013
8.25
4.9
4.9
18
4.5
576.17
575.99
0.50%
182
126
36
0.09
0.55
5
0.013
7.81
4.0
4.0
24
4.2
573.01
572.83
0.50%
103
182
155
0.13
0.55
5
0.013
7.95
3.7
3.7
24
4.1
573.79
573.01
0.50%
104
103
64
0.14
0.55
5
0.013
8.25
0.6
0.6
18
2.6
574.11
573.79
0.50%
105
103
159
0.35
0.55
5
0.013
8.11
2.5
2.5
24
3.7
574.58
573.79
0.50%
106
105
107
0.21
0.55
5
0.013
8.25
1.0
1.0
24
2.8
575.12
574.58
0.50%
108
69
149
0.00
0.55
5
0.013
7.43
6.6
6.6
30
4.8
570.28
569.53
0.50%
109
108
130
0.21
0.55
5
0.013
7.53
6.7
6.7
30
4.8
570.93
570.28
0.50%
208
109
115
5
0.013
7.62
5.9
5.9
24
4.7
571.50
570.93
0.50%
110
208
115
0.37
0.55
5
0.013
7.71
6.0
6.0
24
4.7
572.08
571.50
0.50%
209
110
119
1
5
0.013
7.82
4.5
4.5
24
4.4
572.68
572.08
0.50%
111
209
105
0.47
0.55
5
0.013
7.91
4.5
4.5
24
4.4
573.20
572.68
0.50%
112
111
122
0.21
0.55
5
0.013
8.03
2.5
2.5
18
3.8
573.81
573.20
0.50%
113
112
204
0.35
0.55
5
0.013
8.25
1.6
1.6
15
3.4
574.83
573.81
0.50%
176
121
36
0.14
0.55
5
0.013
8.00
6.0
6.0
24
6.1
569.44
569.08
1.00%
174
176
36
0.04
0.55
5
0.013
8.02
5.4
5.4
18
6.0
569.80
569.44
1.00%
178
174
89
0.18
0.55
5
0.013
8.08
5.2
5.2
18
5.9
570.69
569.80
1.00%
102
178
28
0.24
0.55
5
0.013
8.25
1.1
1.1
15
3.9
575.63
575.35
1.00%
100
178
198
0.41
0.55
5
0.013
8.22
3.4
3.4
18
5.3
572.67
570.69
1.00%
181
100
41
0.34
0.55
5
0.013
8.25
1.6
1.6
18
4.3
573.08
572.67
1.00%
171
119
36
0.18
0.55
5
0.013
8.13
4.3
4.3
15
6.6
574.63
574.09
1.50%
172
171
208
0.78
0.55
5
0.013
8.25
3.6
3.6
15
6.3
577.75
574.63
1.50%
144
118
36
0.54
0.55
5
0.013
7.51
34.3
34.3
36
9.5
574.10
573.74
1.00%
142
144
28
0.12
0.55
5
0.013
7.52
32.1
32.1
36
9.3
574.38
574.10
1.00%
140
142
28
0.36
0.55
5
0.013
7.53
31.7
31.7
36
9.3
574.66
574.38
1.00%
146
140
177
0.06
0.55
5
0.013
7.60
30.5
30.5
30
9.2
576.43
574.66
1.00%
150
146
161
0.28
0.55
5
0.013
7.68
14.5
14.5
30
7.6
578.04
576.43
1.00%
82
150
28
0.02
0.55
5
0.013
7.70
13.3
13.3
30
8.6
578.46
578.04
1.50%
84
82
28
0.33
0.55
5
0.013
7.71
13.2
13.2
24
8.7
578.87
578.46
1.50%
155
84
28
0.30
0.55
5
0.013
7.72
11.8
11.8
24
7.9
579.22
578.87
1.25%
156
155
95
0.31
0.55
5
0.013
7.77
10.6
10.6
24
7.1
580.18
579.22
1.00%
87
156
138
0.31
0.55
5
0.013
7.87
9.4
9.4
18
5.3
581.08
580.18
0.66%
88
87
150
0.31
0.55
5
0.013
7.95
6.3
6.3
18
6.9
583.07
581.08
1.32%
160
88
150
0.31
0.55
5
0.013
8.06
3.6
3.6
18
5.4
584.57
583.07
1.00%
163
160
150
0.10
0.55
5
0.013
8.22
0.8
0.8
18
3.6
586.07
584.57
1.00%
91
163
28
0.09
0.55
5
0.013
8.25
0.4
0.4
18
2.9
586.35
586.07
1.00%
168
160
28
0.31
0.55
5
0.013
8.25
1.4
1.4
18
4.1
584.85
584.57
1.00%
167
88
28
0.31
0.55
5
0.013
8.25
1.4
1.4
18
4.2
583.35
583.07
1.00%
92
87
29
0.41
0.55
5
0.013
8.25
1.9
1.9
18
4.4
581.36
581.08
0.95%
201
146
39
0.05
0.55
5
0.013
7.92
16.6
16.6
24
10.0
577.16
576.43
1.88%
202
201
79
1.06
0.55
5
0.013
7.95
16.4
16.4
24
10.0
578.64
577.16
1.88%
203
202
199
0.66
0.55
5
0.013
8.03
11.8
11.8
24
9.2
582.38
578.64
1.88%
204
203
157
0.65
0.55
5
0.013
8.10
9.0
9.0
24
8.5
585.32
582.38
1.88.
205
204
150
0.65
0.55
5
0.013
8.17
6.11
6.1
18
7.8
588.131
585.321
1.88%
206
205
150
0.71
0.55
5
0.013
8,251
3.21
3.2
15
6.71
590.951
588.13
3 88%
1 THOMAS 6 HUTTON
Z: �27842 �27842.0003 �Engineering� Calculations and Reports�Storm Water�HEC-22�27842.0003 - HEC-22 Reporting

4 IN/HR
INLET
SPREAD

H EC-22
Inlet Capacity Results
Structure
Q=CIA/Kc
(cfs)
Known
Q
(cfs)
Longitudinal
Slope
SL
(ft/ft)
Cross
Slope
Sx
(ft/ft)
Cross
Slope
SW
(ft/ft)
Prev.
Bypass
Flow
(cfs)
Total
Gutter
Flow
(cfs)
Depth
d
(ft)
Gutter
Width
(ft)
Spread
T
(ft)
Inlet Type
Grate
Length
(in)
Grate
Width
(in)
Curb
Opening
Length
(in)
Curb
Opening
Height
(in)
Intercept
Flow
Qi
(cfs)
Bypass
Flow
Qb
(cfs)
Bypass
Structure
Remark
37
0.6
0.07
0.33
0.51
0.6
3.4
0.2
0.0
0.7
Grate inlet
23.8
23.8
0.1
0.5
38
38
2.9
-1.00
0.33
0.7
0.0
2.0
Grate inlet
23.8
23.8
3.4
188
1.5
0.01
0.33
1.5
0.4
0.0
1.3
Grate inlet
23.8
23.8
0.5
1.0
187
187
2.0
-1.00
0.33
1.0
2.9
0.6
0.0
1.8
Grate inlet
23.8
23.8
2.9
13
0.2
0.02
0.02
0.04
0.2
0.1
2.0
2.2
Combination
35.5
23.6
35.5
4.2
0.2
14
12
0.7
0.021
0.02
0.04
0.7
0.1
2.0
4.4
Combination
35.5
23.61
35.5
4.2
0.6
0.1
31
11
0.5
0.01
0.33
0.5
0.3
0.0
0.9
Grate inlet
23.8
23.8
0.3
0.3
10
10
1.1
-1.00
0.33
0.7
1.81
0.4
0.0
1.3
Grate inlet
23.8
23.8
1.8
9
0.7
0.02
0.33
0.7
0.3
0.0
0.9
Grate inlet
23.8
23.8
0.3
0.4
10
8
0.5
-1.00
0.33
0.5
0.2
0.0
0.6
Grate inlet
23.8
23.8
0.5
22
1.8
-1.00
0.02
0.04
1.8
0.2
2.0
5.5
Combination
71.0
23.6
71.01
4.2
1.8
21
1 0.8
-1.001
0.02
0.041
0.1
0.9
0.1
2.01
2.9
Combination
71.01
23.6
71.0
4.2
0.9
20
0.6
0.01
0.02
0.04
0.6
0.1
2.0
4.6
Combination
35.5
23.6
35.5
4.2
0.5
0.1
21
33
1.2
-1.00
0.02
0.04
1.21
0.1
2.0
3.9
Combination
71.0
23.6
71.0
4.2
1.2
34
0.1
0.04
0.02
0.04
0.1
0.1
2.0
1.2
Combination
35.5
23.6
35.5
4.2
0.1
32
15
0.2
0.02
0.02
0.04
0.2
0.1
2.0
2.4
Combination
35.5
23.6
35.5
4.2
0.21
0.0
17
36
1.8
-1.00
0.02
0.04
0.1
1.9
0.2
2.0
5.7
Combination
71.0
23.6
71.01
4.2
1.9
29
1 1.2
-1.00
0.02
0.041
1.2
0.1
2.0
4.0
Combination
71.0
23.6
71.0
4.2
1.2
28
0.1
0.02
0.02
0.04
0.1
0.1
2.0
1.5
Combination
35.5
23.6
35.5
4.2
0.1
29
27
0.1
0.01
0.02
0.04
0.11
0.1
2.0
1.9
Combination
35.5
23.6
35.5
4.2
0.1
12
30
0.7
-1.00
0.02
0.04
0.7
0.1
2.0
2.0
Combination
71.0
23.6
71.0
4.2
0.7
32
1.2
-1.00
0.02
0.04
1.2
0.1
2.0
3.8
Combination
71.0
23.6
71.0
4.21
1.2
35
0.6
0.021
0.02
0.04
0.1
0.6
0.1
2.01
4.2
Combination
35.51
23.6
35.5
4.2
0.6
0.1
36
31
1 0.5
0.02
0.02
0.041
0.1
0.6
0.1
2.0
4.1
Combination
35.5
23.6
35.5
4.2
0.6
0.1
35
14
0.2
0.02
0.02
0.04
0.2
0.1
2.0
1.9
Combination
35.5
23.6
35.5
4.2
0.2
34
19
0.3
0.01
0.02
0.04
0.31
0.1
2.0
3.3
Combination
35.5
23.6
35.5
4.2
0.3
0.0
18
18
0.1
0.04
0.02
0.04
0.0
0.1
0.1
2.0
1.3
Combination
35.5
23.6
35.51
4.2
0.11
17
17
0.7
-1.00
0.02
0.04
0.0
0.7
0.1
2.0
2.0
Combination
71.0
23.6
71.0
4.2
0.7
207
1 0.6
0.01
0.02
0.041
0.6
0.1
2.0
4.8
Combination
35.5
23.6
35.5
4.2
0.5
0.1
49
143
1.6
0.01
0.33
1.6
0.5
0.0
1.4
Grate inlet
23.8
23.8
0.6
1.0
44
44
1.6
0.01
0.33
1.0
2.61
0.5
0.0
1.7
Grate inlet
23.8
23.8
0.8
1.8
43
43
2.1
-1.00
0.33
1.8
3.8
0.7
0.0
2.2
Grate inlet
23.8
23.8
3.8
130
1.3
-1.00
0.33
0.9
2.2
0.5
0.0
1.5
Grate inlet
23.8
23.8
2.2
125
0.9
0.011
0.02
0.04
0.2
1.0
0.2
2.0
6.1
Combination
35.5
23.6
35.5
4.2
0.8
0.2
159
124
1 0.61
0.01
0.02
0.041
0.0
0.6
0.1
2.0
4.9
Combination
35.51
23.6
35.5
4.2
0.6
0.1
50
1.0
0.09
0.33
1.0
0.3
0.0
0.8
Grate inlet
23.8
23.8
0.2
0.9
130
49
0.3
0.01
0.02
0.04
0.2
0.5
0.1
2.0
4.3
Combination
35.5
23.6
35.5
4.2
0.4
0.0
124
47
0.7
0.01
0.02
0.041
1 0.71
0.2
2.0
5.2
Combination
35.51
23.6
35.5
4.2
0.6
0.1149
F4 THOMAS 6 HUTTON
Z:127842127842.00031 EngineeringlCalculations and ReportslStorm WaterIHEC-22127842.0003 - HEC-22 Reporting

H EC-22
Inlet Capacity Results
Structure
Q=CIA/Kc
(cfs)
Known
Q
(cfs)
Longitudinal
Slope
SL
(ft/ft)
Cross
Slope
Sx
(ft/ft)
Cross
Slope
SW
(ft/ft)
Prev.
Bypass
Flow
(cfs)
Total
Gutter
Flow
(cfs)
Depth
d
(ft)
Gutter
Width
(ft)
Spread
T
(ft)
Inlet Type
Grate
Length
(in)
Grate
Width
(in)
Curb
Opening
Length
(in)
Curb
Opening
Height
(in)
Intercept
Flow
Qi
(cfs)
Bypass
Flow
Qb
(cfs)
Bypass
Structure
Remark
153
0.9
0.01
0.02
0.04 0.0 0.9
0.04 0.4
0.041 1 0.1
0.2
2.0
5.8
Combination
35.5
23.6
35.5
4.2
0.7
0.2
125
147
0.4
0.01
0.02
0.11
2.0
4.0
Combination
35.5
23.6
35.5
4.2
0.4
0.0
153
177
0.1
0.02
0.02
0.1
2.0
1.3
Combination
35.5
23.6
35.5
4.2
0.1
107
56
0.1
0.02
0.02
0.04
0.1
0.1
2.0
1.3
Combination
35.5
23.6
35.5
4.2
0.1
55
0.1
0.04
0.02
0.04
0.1
0.1
2.0
1.6
Combination
35.5
23.6
35.5
4.2
0.1
165
165
0.5
0.051
0.02
0.04
0.5
0.1
2.0
3.0
Combination
35.5
23.61
35.5
4.2
0.5
0.0
53
53
0.5
0.04
0.02
0.04
0.0
0.5
0.1
2.0
3.3
Combination
35.5
23.6
35.5
4.2
0.5
0.0
52
52
0.8
0.02
0.02
0.04
0.0
0.8
0.1
2.0
4.9
Combination
35.5
23.6
35.5
4.2
0.7
0.1
159
159
0.9
-1.00
0.02
0.041
0.3
1.3
0.2
2.0
5.6
Combination
35.5
23.6
35.5
4.2
1.3
101
0.5
-1.00
0.02
0.04
0.2
0.7
0.1
2.0
3.3
Combination
35.5
23.6
35.5
4.2
0.7
103
1.0
0.01
0.02
0.04
0.1
1.0
0.2
2.0
5.7
Combination
35.51
23.6
35.51
4.2
0.8
0.2
101
105
1 0.7
0.041
0.02
0.04
0.7
0.1
2.01
3.9
Combination
35.5
23.6
35.5
4.2
0.7
0.1
103
107
1.0
0.05
0.02
0.04
1 1.0
0.1
2.0
4.1
Combination
35.5
23.6
35.5
4.2
0.9
0.1
104
0.3
0.01
0.33
1 0.1
0.5
0.3
0.0
0.8
Grate inlet
23.8
23.8
0.2
0.2
133
0.1
0.01
0.02
0.04
0.1
0.1
2.0
1.8
Combination
35.5
23.6
35.5
4.2
0.1
186
105
0.8
-1.00
0.33
0.3
1.0
0.3
0.0
0.9
Grate inlet
23.81
23.8
1.0
106
1 0.5
0.011
0.33
0.51
0.3
0.01
0.8
Grate inlet
23.8
23.8
0.2
0.31105
172
1.7
0.01
0.33
1.7
0.5
0.0
1.4
Grate inlet
23.8
23.8
0.6
1.2
134
0.8
0.01
0.33
0.1
0.8
0.4
0.0
1.1
Grate inlet
23.8
23.8
0.4
0.5
114
0.2
0.01
0.33
0.2
0.2
0.0
0.6
Grate inlet
23.8
23.8
0.1
0.1
134
112
0.5
-1.00
0.33
0.4
1.0
0.3
0.0
0.9
Grate inlet
23.8
23.8
1.0
131
0.3
0.01
0.02
0.04
0.3
0.1
2.0
3.3
Combination
35.51
23.6
35.5
4.2
0.3
0.0
128
138
1 0.2
0.011
0.02
0.04
0.21
0.1
2.01
3.0
Combination
35.5
23.6
35.5
4.2
0.2
0.0
144
137
0.3
0.01
0.02
0.04
0.3
0.1
2.0
3.7
Combination
35.5
23.6
35.5
4.2
0.3
0.0
115
118
0.6
0.01
0.02
0.04
0.1
0.7
0.2
2.0
5.1
Combination
35.5
23.6
35.5
4.2
0.6
0.1
119
121
0.2
0.01
0.02
0.041
0.2
0.4
0.1
2.0
3.9
Combination
35.5
23.6
35.5
4.2
0.3
0.0
69
69
0.2
0.01
0.02
0.04
0.0
0.2
0.1
2.0
2.7
Combination
35.5
23.6
35.5
4.2
0.21
0.0
126
126
0.6
0.01
0.02
0.04
0.0
0.6
0.1
2.0
4.9
Combination
35.51
23.6
35.5
4.2
0.5
0.1
127
127
1 0.9
0.01
0.02
0.04
0.1
0.9
0.21
2.0
6.0
Combination
35.5
23.6
35.5
4.2
0.7
0.2
128
128
1.7
-1.00
0.02
0.04
0.2
1.9
0.2
2.0
5.9
Combination
71.0
23.6
71.0
4.2
1.9
186
2.4
-1.00
0.02
0.04
0.0
2.4
0.2
2.0
7.1
Combination
71.0
23.6
71.0
4.2
2.4
182
0.2
0.01
0.02
0.04
0.2
0.1
2.0
2.8
Combination
35.5
23.6
35.5
4.2
0.2
0.01186
176
0.3
0.01
0.02
0.04
0.1
0.4
0.1
2.0
3.9
Combination
35.5
23.6
35.5
4.2
0.3
0.0
174
144
1.2
0.011
0.02
0.04
0.0
1.21
0.2
2.01
6.5
Combination
35.51
23.6
35.5
4.2
0.9
0.3
142
102
1 0.51
0.01
0.02
0.041
0.5
0.1
2.0
4.3
Combination
35.5
23.6
35.5
4.2
0.5
0.1
181
181
0.8
0.01
0.02
0.041
0.1
0.8
0.2
2.0
5.2
Combination
35.5
23.6
35.5
4.2
0.7
0.1
142
0.3
-1.00
0.02
0.04
0.3
0.6
0.1
2.0
2.6
Combination
35.5
23.6
35.5
4.2
0.6
140
0.8
0.02
0.02
0.04
0.0
0.8
0.1
2.0
4.7
Combination
35.5
23.6
35.5
4.2
0.7
0.11171
F4 THOMAS 6 HUTTON
Z:127842127842.00031 EngineeringlCalculations and ReportslStorm WaterIHEC-22127842.0003 - HEC-22 Reporting

H EC-22
Inlet Capacity Results
Structure
Q=CIA/Kc
(cfs)
Known
Q
(cfs)
Longitudinal
Slope
SL
(ft/ft)
Cross
Slope
Sx
(ft/ft)
Cross
Slope
SW
(ft/ft)
Prev.
Bypass
Flow
(cfs)
Total
Gutter
Flow
(cfs)
Depth
d
(ft)
Gutter
Width
(ft)
Spread
T
(ft)
Inlet Type
Grate
Length
(in)
Grate
Width
(in)
Curb
Opening
Length
(in)
Curb
Opening
Height
(in)
Intercept
Flow
Qi
(cfs)
Bypass
Flow
Qb
(cfs)
Bypass
Structure
Remark
146
0.1
0.01
0.02
0.04 0.1
0.04 0.6
0.041 1 0.2
0.1
2.0
2.5
Combination
35.5
23.6
35.5
4.2
0.1
0.0
140
150
0.6
0.02
0.02
0.11
2.0
4.3
Combination
35.5
23.6
35.5
4.2
0.6
0.1
91
0.2
0.01
0.02
0.1
2.0
2.6
Combination
35.5
23.6
35.5
4.2
0.2
0.0
168
163
0.2
0.01
0.02
0.04
0.2
0.1
2.0
2.8
Combination
35.5
23.6
35.5
4.2
0.2
0.0
160
160
0.7
0.01
0.02
0.04
0.0
0.7
0.1
2.0
5.0
Combination
35.5
23.6
35.5
4.2
0.6
0.1
88
88
0.7
0.01
0.02
0.04
0.1
0.8
0.2
2.0
5.2
Combination
35.5
23.61
35.5
4.2
0.7
0.1
87
87
0.7
0.01
0.02
0.04
0.1
0.8
0.2
2.0
5.4
Combination
35.5
23.6
35.5
4.2
0.7
0.1
156
155
0.7
-1.00
0.02
0.04
0.1
0.8
0.1
2.0
3.7
Combination
35.5
23.6
35.5
4.2
0.8
84
0.7
0.01
0.02
0.041
0.2
1.0
0.2
2.0
5.8
Combination
35.5
23.6
35.5
4.2
0.8
0.2
82
82
0.1
0.02
0.02
0.04
0.2
0.3
0.1
2.0
2.6
Combination
35.5
23.6
35.5
4.2
0.3
0.0
156
0.7
0.01
0.02
0.04
0.1
0.8
0.2
2.0
5.4
Combination
35.51
23.6
35.51
4.2
0.7
0.1
155
167
1 0.7
0.011
0.02
0.04
0.1
0.8
0.2
2.01
5.3
Combination
35.5
23.6
35.5
4.2
0.7
0.1
92
168
0.7
0.01
0.02
0.04
0.01
0.7
0.1
2.0
5.0
Combination
35.5
23.6
35.5
4.2
0.6
0.1
167
113
0.8
0.01
0.33
0.8
0.4
0.0
1.1
Grate inlet
23.8
23.8
0.4
0.4
112
112
0.5
0.02
0.33
1
0.5
0.3
0.0
0.8
Grate inlet
23.8
23.8
0.2
0.3
111
111
1.1
-1.00
0.33
0.9
1.9
0.4
0.0
1.4
Grate inlet
23.8
23.8
1.9
110
0.8
0.01
0.33
0.2
1.1
0.4
0.0
1.2
Grate inlet
23.81
23.8
0.4
0.6
111
109
1 0.5
0.011
0.33
0.0
0.51
0.3
0.01
0.9
Grate inlet
23.8
23.8
0.2
0.2
110
108
0.0
0.01
0.33
0.0
0.1
0.0
0.2
Grate inlet
23.8
23.8
0.0
0.0
109
92
0.9
0.01
0.02
0.04
0.1
1.1
0.2
2.0
6.0
Combination
35.5
23.6
35.5
4.2
0.8
0.2
84
178
0.4
0.01
0.02
0.041
0.4
0.1
2.0
3.8
Combination
35.5
23.6
35.5
4.2
0.4
0.0
100
100
0.9
0.01
0.02
0.04
0.0
1.0
0.2
2.0
5.7
Combination
35.5
23.6
35.5
4.21
0.8
0.2
115
0.7
0.01
0.02
0.04
0.0
0.7
0.2
2.0
5.1
Combination
35.51
23.6
35.5
4.2
0.6
0.1
118
174
1 0.1
0.011
0.02
0.04
0.0
0.1
0.1
2.0
1.8
Combination
35.5
23.6
35.5
4.2
0.1
178
171
0.4
0.01
0.02
0.04
0.1
0.5
0.1
2.0
4.5
Combination
35.5
23.6
35.5
4.2
0.5
0.1
176
119
0.7
0.01
0.02
0.04
0.1
0.8
0.2
2.0
5.5
Combination
35.5
23.6
35.5
4.2
0.71
0.2
121
103
0.3
0.01
0.33
0.3
0.2
0.01
0.7
Grate inlet
23.8
23.8
0.2
0.1
104
206
1.6
0.01
0.33
1.6
0.4
0.0
1.3
Grate inlet
23.8
23.8
0.6
1.0
205
1.5
0.01
0.33
1.5
0.4
0.0
1.3
Grate inlet
23.81
23.8
0.5
0.9
204
204
1 1.5
0.01
0.33
0.9
2.4
0.5
0.0
1.5
Grate inlet
23.8
23.8
0.7
1.6
203
203
1.51
0.01
0.33
1.61
3.11
0.6
0.0
1.8
Grate inlet
23.8
23.8
1.0
2.2
202
202
2.4
-1.00
0.33
2.21
4.61
0.8
0.0
2.4
Grate inlet
23.8
23.8
1 4.6
201
0.11
0.01
0.331
1
1 0.11
0.2
0.0
0.5
Combination
35.5
23.6
35.5
4.21
0.11
0.01142
F4 THOMAS 6 HUTTON
Z:127842127842.00031 EngineeringlCalculations and ReportslStorm WaterIHEC-22127842.0003 - HEC-22 Reporting

APPENDIX I ITEM 6
STORM DRAIN PIPE
MAXIMUM CAPACITY TABLE
(1) PIPE SIZE
(2) MAXIMUM CAPACITY
12"
6
15"
9
18"
13
24"
25
30"
43
36"
4
42"
90
48"
120
54"
160
60"
200
66"
250
(1) CONCRETE PIPE
(2) CAPACITY (c.f...) BASED ON INLET CONTROL
FOR MAXIMUM DEPTH IN STANDARD CATCH BASIN
6/90

STORMWATER MANAGEMENT REPORT
CRESSWIND WESLEY CHAPEL - PHASE 03
APPENDIX F
WATER QUALITY
CALCULATIONS
27842.0003
Fq THOMAS Sc HUTTON

Water Quality Calculations
Cresswind - Wesley Chapel
Project No. 27842.0003
WET POND 04
Project/Drainage Area:
Acres
Required Water Quality Volume:
46,929 Cubic Feet
Impervious Area:
Acres
"74.7%
(Project Area (Acres) X 43,560 SF X 1"/12 = Required Cubic Feet Volume)
Percent
Impervious
Runoff Coeifficient:
R-05+0.9 (1) = 0.72
(Required Collection of First 1"
of Rainfall from the Project
Site and Release over a Minimum
48 Hour (Maximum
120 Hours) in Cubic Feet Per Second)
Min. 48-Hour Release Rate:
0.272 CPS
Required Orifice Size: 3.00 Drawdown Time (Hours): 63.22
Water Quality Elevation
Orifice Flow Calculation
Elev.
Area
Storage
Q-C,A*sgrt(2gh)
(ft)
(sf)
(cu. ft)
C,= 0.62 (Sharp Orifice)
NWL
567.00
24,979.00
0.00
A= 0.049 sf
TOP OF BERM
573.50
40,748.00
213,612.75
g= 32.174 ft/sz
Elevation
Pond Depth
Storage
h =J 1.43 Ift
(ft)
(ft)
(cu. ft)
Q= 0.206 cfs
567.00
0.00
0.00
568.43
1.43
46,928.64
573.50
6.50
213,612.75
Average Depth Calculation
Vpp Designed @ Elevation
567.00
74,522.00
Permanent Pool SA Designed @ Elev
567.00
19,948.00
Area of wet pond at the bottom of the shelf
18,357.00
Dmax over shelf
0.50
Pedmeter of Permanent Pool
666.00
Width of submerged part of shelf
3.00
Volume over the shelf only
499.50
Average Depth
4.03
SA/DA Method
Drainage Area 17.90 acres
Table value
2.25
Surface Area Required
1 17,543.79 Isquarefeet
VPP-Vrhel f
AbOttOtlrOf.h1 if
wmra: o..,, - n.erhse aeo�h roes
VW = Tda1'-- paimenmi root llea'1
v— - -L, o erineenem oay lreeial-ee•neiow
we.a—weaxinehaim,aene:nwrni
ve,.,= as•DWhm.,.,..e..•vwimear.".,„,•vnanW.,,..,..,."„,...
wne<e: o...._.., = o�inawem. e�maaaBa eiaemma ehercen
rmi ireai
.neu (reeti
wain -a -.=.tea... w�am ha„me oeac eiaemme ory uoeame
Tablea:Piedmont—Mountains—Table f—'--On. —p

Stage Storage Calculations
Cresswind - Wesley Chapel
Project No. 27842.0002
WET POND 04
FOREBAY 01 VOLUME
CONTOUR
CONTOUR
INC. VOL.
CUM. VOL. AVG.
ELEV
AREA (SF)
DEPTH (FT)
AVG. END
END (CU. FT.)
562.5
2,099
N/A
N/A
0
563.5
2,488
1
2,293
2,293
564.5
2,907
1
2,697
4,990
565.5
3,358
1
3,132
8,122
566.5
3,840
1
3,599
11,721
567
4,540
0.5
2,095
13,816
TOTAL FOREBAY VOLUME: I13,816 CU.FT
PERCENTAGE OF PERMANENT POOL VOLUME: 1 19%
PERMANENT POOL VOLUME
CONTOUR
CONTOUR
INC. VOL.
CUM. VOL. AVG.
DEPTH (FT)
ELEV
AREA (SF)
AVG. END
END (CU. FT.)
562.5
14,190
N/A
N/A
0
563.5
15,191
1
14,690
14,690
564.5
16,219
1
15,702
30,392
565.5
17,275
1
16,744
47,136
566.5
18,357
1
17,813
64,949
567
19,948
0.5
9,573
74,522
PERMANENT POOL VOLUME: I 74,522 CU.FT
TEMPORARY PONDING ZONE
CONTOUR
CONTOUR
INC. VOL.
CUM. VOL. AVG.
DEPTH (FT)
ELEV
AREA (SF)
AVG. END
END (CU. FT.)
567
24,979
N/A
N/A
0
567.5
27,062
0.5
13,010
13,010
568.5
29,202
1
28,132
41,142
569.5
31,398
1
30,300
71,442
570.5
33,651
1
32,525
103,967
571.5
35,960
1
34,806
138,773
572.5
38,326
1
37,143
175,916
573.5
40,748
1
39,538
215,454
TEMPORARY PONDING ZONE VOLUME: 215,454 CU. FT.

Cresswind Wesley Chapel - Phase 04
Job:
J-27842.0003
T
KH Wesley Chapel, LLC
Date:
2/18/21
c
H
Thomas & Hutton Engineering Co.
Revised:
9/9/21
Anti -Flotation Design Considerations
By:
MSK
ANTI -FLOTATION DESIGN CONSIDERATIONS FOR:
Wet Pond 02
CONTROL STUCTURE ELEVATIONS
Top Structure Elevation: 573.00
Bottom Structure Elevation: 562.50
CONTROL STRUCTURE FLOTATION
Buovant Force
Calculate submerged volume:
Vs = (Acs x Hcs)
Where:
VS = Submerged volume (cf)
Les = Length of control structure (ft) = 10.50 ft
Wes = Width of Control structure (ft) = 5.00 ft
Aes- Cross -sectional area of control structure (ft) = 52.50 ft
Hes = Height of control structure (ft) = 10.50 ft
Solve equation for Vs:
VS = (Aes x H. = 551.25 cf
Calculate buoyant force:
Fb = Vs x ywater
Where:
Fb = buoyant force (lbf)
ywater = Specific weight of water = 62.40 lbf/cf
Fb = 34,398 lbf
Z:\27842\27842.0003\Engineering\Calculations and Reports\Storm Water\Anti Flotation\27842.0003 - Wet Pond 04 - Anti Flotation
Design Calculations Page 1 of 3

Cresswind Wesley Chapel - Phase 04
Job:
J-27842.0003
T
KH Wesley Chapel, LLC
Date:
2/18/21
c
H
Thomas & Hutton Engineering Co.
Revised:
9/9/21
Anti -Flotation Design Considerations
By:
MSK
Downward Force
Calculate Downward Force of Control Structure
Fdcs — (Ves — Vweir — Vorifiej X yconcrete
Where:
WteS =
Weight of control structure (lbs)
Yconcrete =
Specific weight of concrete
= 140.00 lbf/cf
Ac, =
Cross -sectional area of control structure (ft)
= 52.50 ft
Hcs =
Height of control structure (ft)
= 10.50 ft
TCS =
Wall thickness of control structure (ft)
= 0.50 ft
VCS =
Volume of control structure (cf)
= 152.25 cf
Wweir =
Width of weir (ft)
= 2.00 ft
Hweir =
Height of weir opening (ft)
= 4.00 ft
Aweir =
Area of weir opening(ft)
= 8.00 sf
Vweir =
Volume of weir
= 4.00 cf
DIAorif,ce =
Diameter of orifice opening (in)
= 3.00 in
Aoriace =
Area of orifice opening (sf)
= 0.049 sf
Vorifee =
Volume of orifice opening (sf)
= 0.025 cf
FdeS = 20,752 lbf
Size Anti -Flotation Footing to Resist Bouyant Force
FdeS + Fdft > Fb
Fdft = (Lb X Wb X Db) X Yco=&r
Where:
FdeS =
downward force of control structure (lbf) =
20752 lbf
Fb =
buoyant force (lbf) =
34398 lbf
Yconcrete =
Specific weight of concrete =
77.60 lbf/cf
Lb =
Length of Concrete Block =
14.00 ft
Wb =
Width of Concrete Block =
14.00 ft
Db =
Depth of Concrete Block =
12.00 in
Fdft =
downward force of anti -flotation footing (lbf) =
15210 lbf
Z:\27842\27842.0003\Engineering\Calculations and Reports\Storm Water\Anti Flotation\27842.0003 - Wet Pond 04 - Anti Flotation
Design Calculations Page 2 of 3

Cresswind Wesley Chapel - Phase 04
Job:
J-27842.0003
T
KH Wesley Chapel, LLC
Date:
2/18/21
c
H
Thomas & Hutton Engineering Co.
Revised:
9/9/21
Anti -Flotation Design Considerations
By:
MSK
Fd,s + Fdit = 35961 IV > Fb = 34398 lbf
Factor of Safety
Confirm anti -flotation block is sized for minimum factor of safety (Fj of 1.10.
Fs = (Fd. + Fdft)/]Fb
1.05 > 1.10 Too SMALL
Z:\27842\27842.0003\Engineering\Calculations and Reports\Storm Water\Anti Flotation\27842.0003 - Wet Pond 04 - Anti Flotation
Design Calculations Page 3 of 3