SW3240201_Stormwater Report_20240603

STORMWATER MANAGEMENT REPORT
FOR:
CRESSWIND WESLEY CHAPEL - PHASE 05
WESLEY CHAPEL, NC
PREPARED FOR:
KH WESLEY CHAPEL, LLC
„. THUTT0
//1S9484. N HUTTOS N -#27842.0005
049480 - _ ENGINEERING : _
6/.3/24 F`• No. F-087I ' o
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REVISED: MAY 29, 2024
Prepared by:
HT THOMAS & HUTTON

STORMWATER MANAGEMENT REPORT
Cresswind Wesley Chapel - Phase 05
Project: Cresswind Wesley Chapel - Phase 05
T&H Job Number: J-27842.0005
Location: Potter Road
Wesley Chapel, NC 28173
Date Prepared: February 17, 2023
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
Section 3- Purpose Page 4
Section 4- Regulatory Summary Page 5
Section 5-Methodology Page 5
Section 6- Hydrology Page 6
Section 7- Runoff Calculations Page 6
Section 8- Existing Conditions Page 8
Section 9- Post Development Conditions Page 8
APPENDICES
Project Mapping Appendix A
Aerial Location Map Exhibit A
FEMA Map Exhibit B
Wetlands Map Exhibit D
Soils Map 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 Ouffall 01
(cfs)
2-year 40
10-Year 88
25-Year 116
50-Year 141
Table 2- Post Development Runoff Rates
TABLE 1
Summary of Results- Proposed Conditions
Storm Event Outfall 01
(cfs)
2-year 8
10-Year 28
25-Year 44
50-Year 61
H THOMAS & HUTTON
Page 3

SECTION 2 - PROJECT NARRATIVE
Cresswind is a residential subdivision within Wesley Chapel, North Carolina. Phase 5 consists of
approximately 104 single family detached units. The site is located in Union County along Potter
Road, north of Newtown Road and south of Weddington Road.
The majority of the site is currently wooded with an understory of brush. Pre-development run-
off is discharged into an existing wetland system and FEMA Floodplain. The pre-development
drainage basins have been delineated and are illustrated on the Pre-Development Drainage
Exhibit found at the end of this report.
For the purpose of this report, we will compare the 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, and B/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.
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
H THOMAS & HUTTON
Page 5

conveyance such as pipes, channels, control structures, weirs, etc. The sizes, inverts, lengths, and
Manning "n" values for all pipes connecting the ponds or lakes are input into the model. In
addition to pipe information, all pond, lake, and detention area stage-area information and the
respective control structure information is input into the model. The node and link conditions are
analyzed within the model for a given storm, and flow conditions are determined.
Hydrographs for each drainage area are merged within the SSA program, and the hydrologic
results are then combined with the hydraulic information to model the hydraulic interactions of
the entire drainage system. The results include pond area and discharge rates and stage/storage
information during the storm events.
The storm drainage infrastructure onsite was modelled using the Storm Sewers program developed
by Autodesk. This program utilizes the model rainfall and stormwater runoff through the storm
drainage infrastructure to provide hydraulic grade line calculations and profiles for analyzing the
proposed storm drain network.
SECTION 6 - HYDROLOGY
• 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
Curve numbers were generated according to procedures set forth in SCS Technical
Release 55. The composite curve numbers for each drainage basin were calculated
H THOMAS & HUTTON
Page 6

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) Symbol Dimension Units
0.007(nL)°,8 n Manning's n --
t1 — P 0.05 X S°4 L Length of flow ft
2 2 yr event
P2 rainfall in
S Slope ft/ft
Shallow Concentrated Flow: (hr) Symbol Dimension Units
L L Length of flow ft
t2 3600 X V V* Velocity ft/s
*Based on TR-55 velocity-slope relationship
Channel Flow: (hr) Symbol Dimension Units
L L Length of flow ft
t3 3600 X V V* Velocity ft/s
*Assumed to be 2 ft/s
Time of Concentration: (hr)
tc = tl + t2 + t3
Appendices C and E with time of concentration information are attached.
H THOMAS & HUTTON
Page 7

SECTION 8 - EXISTING CONDITIONS
The total acreage of the drainage basins analyzed in the stormwater calculations is
approximately 40 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 40 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 101 single family lots in Phase 5 and
associated 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 pond was designed to meet criteria found in the NCDEQ BMP Design
Manual. Additionally, the required freeboard has been provided beneath the emergency
spillways and the pond embankments for the (50) year storm event. The following tables illustrate
the maximum water surface elevation for the two (2) year, ten (10) year, twenty-five (25) year, fifty
(50) year, and one hundred (100) year storms.
H THOMAS & HUTTON
Page 8

Table 3-Wet Detention Pond 06
Bottom of Pond = 577.50
Normal Pool = 582.50
Crest of Emergency Spillway = 586.50
Top of Embankment = 588.00
Wet Detention Pond 04
Max Elevation
Storm Event
(ftf)
2-Year 584.53
10-Year 585.56
25-Year 586.12
50-Year 586.58
100-Year 586.79
H THOMAS & HUTTON
Page 9

STORMWATER MANAGEMENT REPORT
CRESSWIND WESLEY CHAPEL - PHASE 05
APPENDIX A
PROJECT MAPPING
27842.0005
1.11
THOMAS & HUTTON

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a Hydrologic Soil Group—Union County,North Carolina
(Soils) fn
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Meters
8 N 0 50 100 200 300 8
Feet
0 300 600 m oo 1200 1800
Map projection:Web Mer ator Coer ordirlates:WG584 Edge tics:UTM Zone 17N WGS84
USDA Natural Resources Web Soil Survey 12/3/2021
111-1-11 Conservation Service National Cooperative Soil Survey Page 1 of 4

Hydrologic Soil Group—Union County,North Carolina
(Soils)
MAP LEGEND MAP INFORMATION
Area of Interest(AOI) p c The soil surveys that comprise your AOI were mapped at
Area of Interest(AOI) 1:24,000.
0 CID
Soils • D Warning:Soil Map may not be valid at this scale.
Soil Rating Polygons
l A p Not rated or not available Enlargement of maps beyond the scale of mapping can cause
misunderstanding of the detail of mapping and accuracy of soil
n A/D Water Features line placement.The maps do not show the small areas of
Streams and Canals contrasting soils that could have been shown at a more detailed
n B scale.
Transportation
Q B/D
r4-1. Rails Please rely on the bar scale on each map sheet for map
n C measurements.
ti Interstate Highways
n CID US Routes Source of Map: Natural Resources Conservation Service
Web Soil Survey URL:
0 D Major Roads Coordinate System: Web Mercator(EPSG:3857)
n Not rated or not available Local Roads
Maps from the Web Soil Survey are based on the Web Mercator
Soil Rating Lines Background projection,which preserves direction and shape but distorts
• • A distance and area.A projection that preserves area,such as the
1111 Aerial Photography Albers equal-area conic projection,should be used if more
• • A/D accurate calculations of distance or area are required.
^r B This product is generated from the USDA-NRCS certified data as
.v B/D of the version date(s)listed below.
• r C Soil Survey Area: Union County, North Carolina
Survey Area Data: Version 21,Sep 15,2021
• • CID
Soil map units are labeled(as space allows)for map scales
• • D 1:50,000 or larger.
• w Not rated or not available Date(s)aerial images were photographed: Jul 18,2011—Oct 30,
Soil Rating Points 2018
p A The orthophoto or other base map on which the soil lines were
compiled and digitized probably differs from the background
O A/D imagery displayed on these maps.As a result,some minor
• B shifting of map unit boundaries may be evident.
• B/D
USDA Natural Resources Web Soil Survey 12/3/2021
Conservation Service National Cooperative Soil Survey Page 2 of 4

Hydrologic Soil Group—Union County, North Carolina Soils
Hydrologic Soil Group
Map unit symbol Map unit name Rating Acres in AOI Percent of AOI
BdB2 Badin channery silty C 16.4 16.0%
clay loam,2 to 8
percent slopes,
moderately eroded
ChA Chewacla silt loam,0 to B/D 11.6 11.3%
2 percent slopes,
frequently flooded
GsC Goldston-Badin D 5.4 5.3%
complex,8 to 15
percent slopes
TbB2 Tarrus gravelly silty clay B 69.1 67.4%
loam,2 to 8 percent
slopes,moderately
eroded
Totals for Area of Interest 102.6 100.0%
USDA Natural Resources Web Soil Survey 12/3/2021
1111-1. Conservation Service National Cooperative Soil Survey Page 3 of 4

STORMWATER MANAGEMENT REPORT
CRESSWIND WESLEY CHAPEL - PHASE 05
APPENDIX B
PRE-DEVELOPMENT DRAINAGE MAP
27842.0005
1.11
THOMAS & HUTTON

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ll�ll/ 11)J�°(/� 1 CN:72 ..n '\---.,� �� OUTF ALL 01; '�-
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www.thomasandhutton.com
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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 05
APPENDIX C
PRE-DEVELOPMENT CONDITIONS
DRAINAGE CALCULATIONS
27842.0005
1-
H
THOMAS & HUTTON

Pre-Development 02-Year Page 1
Project Description
File Name 27842.0005-Pre dvelopment.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 00:00:00 0:00:00
End Analysis On 00:00:00 0:00:00
Start Reporting On 00:00:00 0:00:00
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 1 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)
49 Time Series TS-002 Intensity inches North Carolina Union 2.00 3.50 SCS Type II 24-hr

Pre-Development 02-Year Page 2
Subbasin Summary
SN Subbasin Area Peak Rate Weighted Total Total Total Peak Time of
ID Factor Curve Rainfall Runoff Runoff Runoff Concentration
Number Volume
(ac) (in) (in) (ac-in) (cfs) (days hh:mm:ss)
1 Sub-36 40.66 484.00 73.05 3.50 1.18 48.10 40.93 0 00:29:07

Pre-Development 02-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-28 Outfall 0.00 0.00 0.00

Pre-Development 02-Year Page 4
Subbasin Hydrology
Subbasin:Sub-36
Input Data
Area(ac) 40.66
Peak Rate Factor 484
Weighted Curve Number 73.05
Rain Gage ID Rain Gage-001
Composite Curve Number
32 Area Soil Curve
Soil/Surface Description (acres) Group Number
Woods&grass combination,Poor 40.49 B 73
Woods&grass combination,Poor 0.17 D 86
Composite Area&Weighted CN 40.66 73.05
Time of Concentration
TOC Method:SCS TR-55
Sheet Flow Equation:
Tc=(0.007*((n*Lf)^0.8))/(0^0.5)*(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

Pre-Development 02-Year Page 5
Subarea Subarea Subarea
Sheet Flow Computations A B C
Manning's Roughness: 0.4 0 0
Flow Length(ft): 100 0 0
Slope(%): 1.5 0 0
2 yr,24 hr Rainfall(in): 3.5 0 0
Velocity(ft/sec): 0.07 0 0
Computed Flow Time(min): 23.04 0 0
Subarea Subarea Subarea
Shallow Concentrated Flow Computations A B C
Flow Length(ft): 1128 0 0
Slope(%): 3.67 0 0
Surface Type: Unpaved Unpaved Unpaved
Velocity(ft/sec): 3.09 0 0
Computed Flow Time(min): 6.08 0 0
Total TOC(min) 29.12
Subbasin Runoff Results
Total Rainfall(in) 3.5
Total Runoff(in) 1.18
Peak Runoff(cfs) 40.93
Weighted Curve Number 73.05
Time of Concentration(days hh:mm:ss) 0 00:29:07

Pre-Development 02-Year Page 6
Subbasin:Sub-36
Rainfall Intensity Graph
5
4.81
4.6.
4.4
4.2
4
3.8
3.47
3.2-
3
L 2.8
c
2.6
m 2.4-
c
if 2.2
0! 2
1.8
1.6
1.4
1.2
1
0.8
0.6
0.4
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
44
42
40-
38
36-
34-
32-
30-
28
26-
y 24
U
22-
o
7 20-
CC
18
16-
14
12-
10
8
6-
4
2-
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23
Time(hrs)

Pre-Development 10-Year Page 1
Project Description
File Name 27842.0005-Pre dvelopment.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 00:00:00 0:00:00
End Analysis On 00:00:00 0:00:00
Start Reporting On 00:00:00 0:00:00
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 1 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)
49 Time Series TS-010 Intensity inches North Carolina Union 10.00 5.20 SCS Type II 24-hr

Pre-Development 10-Year Page 2
Subbasin Summary
SN Subbasin Area Peak Rate Weighted Total Total Total Peak Time of
ID Factor Curve Rainfall Runoff Runoff Runoff Concentration
Number Volume
(ac) (in) (in) (ac-in) (cfs) (days hh:mm:ss)
1 Sub-36 40.66 484.00 73.05 5.20 2.44 99.33 88.53 0 00:29:07

Pre-Development 10-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-28 Outfall 0.00 0.00 0.00

Pre-Development 10-Year Page 4
Subbasin Hydrology
Subbasin:Sub-36
Input Data
Area(ac) 40.66
Peak Rate Factor 484
Weighted Curve Number 73.05
Rain Gage ID Rain Gage-001
Composite Curve Number
32 Area Soil Curve
Soil/Surface Description (acres) Group Number
Woods&grass combination,Poor 40.49 B 73
Woods&grass combination,Poor 0.17 D 86
Composite Area&Weighted CN 40.66 73.05
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

Pre-Development 10-Year Page 5
Subarea Subarea Subarea
Sheet Flow Computations A B C
Manning's Roughness: 0.4 0 0
Flow Length(ft): 100 0 0
Slope(%): 1.5 0 0
2 yr,24 hr Rainfall(in): 3.5 0 0
Velocity(ft/sec): 0.07 0 0
Computed Flow Time(min): 23.04 0 0
Subarea Subarea Subarea
Shallow Concentrated Flow Computations A B C
Flow Length(ft): 1128 0 0
Slope(%): 3.67 0 0
Surface Type: Unpaved Unpaved Unpaved
Velocity(ft/sec): 3.09 0 0
Computed Flow Time(min): 6.08 0 0
Total TOC(min) 29.12
Subbasin Runoff Results
Total Rainfall(in) 5.2
Total Runoff(in) 2.44
Peak Runoff(cfs) 88.53
Weighted Curve Number 73.05
Time of Concentration(days hh:mm:ss) 0 00:29:07

Pre-Development 10-Year Page 6
Subbasin:Sub-36
Rainfall Intensity Graph
7.5
7-
6.5-
6
5.5
5 •
L4.5-
- �
c 4
m
-c 3.5
•m
0! 3
2.5
2
1.5 •
1
0.5
O 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
95
90
75-
65
- 55-
N
50
0 45-
z
• 40
35
30-
25
20
15-
10
O 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23
Time(hrs)

Pre-Development 25-Year Page 1
Project Description
File Name 27842.0005-Pre dvelopment.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 00:00:00 0:00:00
End Analysis On 00:00:00 0:00:00
Start Reporting On 00:00:00 0:00:00
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 1 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)
49 Time Series TS-025 Intensity inches North Carolina Union 25.00 6.10 SCS Type II 24-hr

Pre-Development 25-Year Page 2
Subbasin Summary
SN Subbasin Area Peak Rate Weighted Total Total Total Peak Time of
ID Factor Curve Rainfall Runoff Runoff Runoff Concentration
Number Volume
(ac) (in) (in) (ac-in) (cfs) (days hh:mm:ss)
1 Sub-36 40.66 484.00 73.05 6.10 3.18 129.18 115.97 0 00:29:07

Pre-Development 25-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-28 Outfall 0.00 0.00 0.00

Pre-Development 25-Year Page 4
Subbasin Hydrology
Subbasin:Sub-36
Input Data
Area(ac) 40.66
Peak Rate Factor 484
Weighted Curve Number 73.05
Rain Gage ID Rain Gage-001
Composite Curve Number
32 Area Soil Curve
Soil/Surface Description (acres) Group Number
Woods&grass combination,Poor 40.49 B 73
Woods&grass combination,Poor 0.17 D 86
Composite Area&Weighted CN 40.66 73.05
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

Pre-Development 25-Year Page 5
Subarea Subarea Subarea
Sheet Flow Computations A B C
Manning's Roughness: 0.4 0 0
Flow Length(ft): 100 0 0
Slope(%): 1.5 0 0
2 yr,24 hr Rainfall(in): 3.5 0 0
Velocity(ft/sec): 0.07 0 0
Computed Flow Time(min): 23.04 0 0
Subarea Subarea Subarea
Shallow Concentrated Flow Computations A B C
Flow Length(ft): 1128 0 0
Slope(%): 3.67 0 0
Surface Type: Unpaved Unpaved Unpaved
Velocity(ft/sec): 3.09 0 0
Computed Flow Time(min): 6.08 0 0
Total TOC(min) 29.12
Subbasin Runoff Results
Total Rainfall(in) 6.1
Total Runoff(in) 3.18
Peak Runoff(cfs) 115.97
Weighted Curve Number 73.05
Time of Concentration(days hh:mm:ss) 0 00:29:07

Pre-Development 25-Year Page 6
Subbasin:Sub-36
Rainfall Intensity Graph
85
8—
7.5
7
6.5—
6
5.5
5
t _
4.5
@ 4
0!▪ 3.5
3
2.5
2
1.5—
1
0.5
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)
Runoff Hydrograph
125
120
115
110
105
100
95
90
85
80
75
n 70
- 65
O 60
0!
• 55
50
45
40
35
30
25
20
15
10
5
i
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23
Time(hrs)

Pre-Development 25-Year Page 1
Project Description
File Name 27842.0005-Pre dvelopment.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 00:00:00 0:00:00
End Analysis On 00:00:00 0:00:00
Start Reporting On 00:00:00 0:00:00
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 1 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)
49 Time Series TS-050 Intensity inches North Carolina Union 50.00 6.90 SCS Type II 24-hr

Pre-Development 25-Year Page 2
Subbasin Summary
SN Subbasin Area Peak Rate Weighted Total Total Total Peak Time of
ID Factor Curve Rainfall Runoff Runoff Runoff Concentration
Number Volume
(ac) (in) (in) (ac-in) (cfs) (days hh:mm:ss)
1 Sub-36 40.66 484.00 73.05 6.90 3.85 156.70 140.98 0 00:29:07

Pre-Development 25-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-28 Outfall 0.00 0.00 0.00

Pre-Development 25-Year Page 4
Subbasin Hydrology
Subbasin:Sub-36
Input Data
Area(ac) 40.66
Peak Rate Factor 484
Weighted Curve Number 73.05
Rain Gage ID Rain Gage-001
Composite Curve Number
32 Area Soil Curve
Soil/Surface Description (acres) Group Number
Woods&grass combination,Poor 40.49 B 73
Woods&grass combination,Poor 0.17 D 86
Composite Area&Weighted CN 40.66 73.05
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

Pre-Development 25-Year Page 5
Subarea Subarea Subarea
Sheet Flow Computations A B C
Manning's Roughness: 0.4 0 0
Flow Length(ft): 100 0 0
Slope(%): 1.5 0 0
2 yr,24 hr Rainfall(in): 3.5 0 0
Velocity(ft/sec): 0.07 0 0
Computed Flow Time(min): 23.04 0 0
Subarea Subarea Subarea
Shallow Concentrated Flow Computations A B C
Flow Length(ft): 1128 0 0
Slope(%): 3.67 0 0
Surface Type: Unpaved Unpaved Unpaved
Velocity(ft/sec): 3.09 0 0
Computed Flow Time(min): 6.08 0 0
Total TOC(min) 29.12
Subbasin Runoff Results
Total Rainfall(in) 6.9
Total Runoff(in) 3.85
Peak Runoff(cfs) 140.98
Weighted Curve Number 73.05
Time of Concentration(days hh:mm:ss) 0 00:29:07

Pre-Development 25-Year Page 6
Subbasin:Sub-36
Rainfall Intensity Graph
9.5
9
8.5-
8-
7.5-
7_
6.5
6-
t 5.5-
5
4.5-
cm
ix 4
3.5
3-
2.5
2
1.5-
1
0.5
F
O 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
155
150
145
140
135
130
125
120
115
110
105
100
95 -
• 90
w 85
• 80
0 75
S 70
6! 65 —
60
55
50
45
40
35
30
25
20
15
10
5
O 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23
Time(hrs)

Pre-Development 100-Year Page 1
Project Description
File Name 27842.0005-Pre dvelopment.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 00:00:00 0:00:00
End Analysis On 00:00:00 0:00:00
Start Reporting On 00:00:00 0:00:00
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 1 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)
49 Time Series TS-100 Intensity inches North Carolina Union 100.00 7.50 SCS Type II 24-hr

Pre-Development 100-Year Page 2
Subbasin Summary
SN Subbasin Area Peak Rate Weighted Total Total Total Peak Time of
ID Factor Curve Rainfall Runoff Runoff Runoff Concentration
Number Volume
(ac) (in) (in) (ac-in) (cfs) (days hh:mm:ss)
1 Sub-36 40.66 484.00 73.05 7.50 4.38 177.89 160.08 0 00:29:07

Pre-Development 100-Year Page 3
Node Summary
SN Element Element Invert Ground/Rim Initial Surcharge Ponded Peak Max HGL Max Min Time of Total Total Time
ID Type Elevation (Max) Water Elevation Area Inflow Elevation Surcharge Freeboard Peak Flooded Flooded
Elevation Elevation Attained Depth Attained Flooding Volume
Attained Occurrence
(ft) (ft) (ft) (ft) (ft') (cfs) (ft) (ft) (ft)(days hh:mm) (ac-in) (min)
1 Out-28 Outfall 0.00 0.00 0.00

Pre-Development 100-Year Page 4
Subbasin Hydrology
Subbasin:Sub-36
Input Data
Area(ac) 40.66
Peak Rate Factor 484
Weighted Curve Number 73.05
Rain Gage ID Rain Gage-001
Composite Curve Number
32 Area Soil Curve
Soil/Surface Description (acres) Group Number
Woods&grass combination,Poor 40.49 B 73
Woods&grass combination,Poor 0.17 D 86
Composite Area&Weighted CN 40.66 73.05
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

Pre-Development 100-Year Page 5
Subarea Subarea Subarea
Sheet Flow Computations A B C
Manning's Roughness: 0.4 0 0
Flow Length(ft): 100 0 0
Slope(%): 1.5 0 0
2 yr,24 hr Rainfall(in): 3.5 0 0
Velocity(ft/sec): 0.07 0 0
Computed Flow Time(min): 23.04 0 0
Subarea Subarea Subarea
Shallow Concentrated Flow Computations A B C
Flow Length(ft): 1128 0 0
Slope(%): 3.67 0 0
Surface Type: Unpaved Unpaved Unpaved
Velocity(ft/sec): 3.09 0 0
Computed Flow Time(min): 6.08 0 0
Total TOC(min) 29.12
Subbasin Runoff Results
Total Rainfall(in) 7.5
Total Runoff(in) 4.38
Peak Runoff(cfs) 160.08
Weighted Curve Number 73.05
Time of Concentration(days hh:mm:ss) 0 00:29:07

Pre-Development 100-Year Page 6
Subbasin:Sub-36
Rainfall Intensity Graph
10.5
10
9.5
9
8.5
8
7.5-
L.
7
6.5 •
t 6_ •
c 5.5 •
-
-
5
ce
4.5
4
3.5
3-
2.5-
2-
1.5-
1-
0.5-
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)
Runoff Hydrograph
170
160
150-
140
130-
120
110-
100
n -
90
c 80
z
0! "
70
60
50
40
30-
20-
10-
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23
Time(hrs)

STORMWATER MANAGEMENT REPORT
CRESSWIND WESLEY CHAPEL - PHASE 05
APPENDIX D
POST-DEVELOPMENT
DRAINAGE MAP
27842.0005
1.11
THOMAS & HUTTON

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STORMWATER MANAGEMENT REPORT
CRESSWIND WESLEY CHAPEL - PHASE 05
APPENDIX E
POST-DEVELOPMENT CONDITIONS
DRAINAGE CALCULATIONS
27842.0005
T
THOMAS & HUTTON

i

Post-Development 002-Year Page 1
Project Description
File Name 27842.0005-Post.SPF
Project Options
Flow Units CFS
Elevation Type Elevation
HydrologyMethod SCS TR 55
Time of Concentration('IOC)Ivvthod SCS TR 55
link Routing Ivlthod Hydrodynamic
Enable OwrflowPonding at Nodes YES
Skip Steady State Analysis Time Periods NO
Analysis Options
Start Analysis On 00:00:00 0:00:00
End Analysis On 00:00:00 0:00:00
Start Reporting On 00:00:00 0:00:00
Antecedent DryDays 0 days
Runoff(Dry Weather)Time Step 0 01:00:00 days hh:mm:ss
Runoff(Wet Weather)Tune Step 0 00:05:00 days hh:mm:ss
Reporting lime Step 0 00:05:00 days hh:mm:ss
Routing Time Step 1 seconds
Number of Elements
ety
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
Wens 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)
49 Time Series 1S-002 Intensity inches North Carolina Union 2.00 3.50 SCS Type uI24-hr

Post-Development 002-Year Page 2
Subbasin Summary
SN Subbasin Area PeakRate Weighted Total Total Total Peak Time of
ID Factor Curve Rainfall Runoff Runoff Runoff Concentration
Number Volume
(ac) (in) (in) (ac-in) (cfs) (days hh:mm:ss)
1 Sub-53 11.43 484.00 65.42 3.50 0.77 8.83 8.53 0 00:05:00
2 Sub-55 30.93 484.00 82.75 3.50 1.84 56.88 59.59 0 00:05:00

Post-Development 002-Year Page 3
Node Summary
SN Element Element Invert Ground/Rim Initial Surcharge Ponded Peak IvhxHGL Max Mn Time of Total Total lime
ID Type Elevation (Ivhx) Water Elevation Area Inflow Elevation Surcharge Freeboard Peak Hooded Flooded
Elevation Elevation Attained Depth Attained Flooding Volume
Attained Occurrence
(It) (fl) (fl) (0) (ft') (cfs) (0) (0) (0) (days hh:mm) (ac-in) (min)
1 CS-05 Junction 578.00 586.50 582.50 999.00 1.00 4.44 582.49 0.00 4.01 0 00:00 0.00 0.00
2 Out-29 Outfall 574.20 46.43 575.61
3 Out-spillway-03 Outfall 574.20 0.00 574.20
4 Pond-06 Storage Node 578.00 588.00 582.50 1.00 58.35 584.53 0.00 0.00

Post-Development 002-Year Page 4
link Summary
SNElement 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
(8) (It) (It) (%) (in) (cfs) (cfs) (ft/sec) (6) (min)
1 L nk-05 Pipe CS-05 Out-29 83.52 578.00 574.20 4.5500 30.000 0.0150 46.43 75.83 0.61 15.46 0.43 0.78 0.00 Calculated
2 CS-RIM-05 Orifice Pond-06 CS-05 578.00 578.00 60.000 0.00
3 Orifice-05 Orifice Pond-06 CS-05 578.00 578.00 4.000 0.59
4 FMERSPILLWAY-05 Weir Pond-06 Out-spillway-03 578.00 574.20 0.00
5 WEIR-OS Weir Pond-06 CS-05 578.00 578.00 3.85

Post-Development 002-Year Page 5
Subbas in Hydrology
Subbasin:Sub-53
Input Data
Area(ac) 11.43
Peak Rate Factor 484
Weighted Curve Number 65.42
Rain Gage ID
Composite Curve Number
32 Area Soil Curve
Soil/Surface Description (acres) Group Number
>75%grass cover,Good 9.98 B 61
>75%grass cover,Good 0.17 D 80
Paved roads with curbs&sewers 1.28 A 98
Composite Area&Weighted CN 11.43 65.42
Time of Concentration
TOC Ivbthod:SCS TR 55
Sheet Flow Equation:
Tc=(0.007*((n*If)^0.8))/((P^0.5)*(SP0.4))
Where:
Tc=Time of Concentration(hr)
n =Ivfanning's roughness
If=Flow Length(ft)
P =2 yr,24 hr Rainfall(inches)
Sf=Slope(ft/ft)
Shallow Concentrated Flow Equation:
V=16.1345*(SP0.5)(unpaved surface)
V=20.3282*(Sf 0.5)(paved surface)
V=15.0*(SP0.5)(grassed waterway surface)
V=10.0*(Sf 0.5)(nearlybare&untitled surface)
V=9.0*(S1n0.5)(cultivated straight rows surface)
V=7.0*(S14.5)(short grass pasture surface)
V=5.0*(Sf`0.5)(woodland surface)
V=2.5*(SP`0.5)(forest w/heavy litter surface)
Tc=(If/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))*(SP`0.5))/n
R=AI/Wp
Tc=(Lf/\ /(3600sec/hr)
Where:
Tc=Time of Concentration(hr)
Lf=Flow Length(ft)
R=Hydraulic Radius(ft)
Aq=Flow Area(ft5)
Wp=Wetted Perimeter(ft)
V=Velocity(ft/sec)
Sf=Slope(ft/ft)
n=Ivhnningsroughness
User-Defined TOC override(minutes):5
Subbasin RunoffRe sults
Total Rainfall(in) 3.5
Total Runoff(in) 0.77

Post-Development 002-Year Page 6
Peak Runoff(cfs) 8.53
Weighted Curve Number 65.42
Tune of Concentration(days hh:mm:ss) 000:05:00

Post-Development 002-Year Page 7
Subbasin:Sub-53
Rainfall Intensity Graph
3
2.9-
2.8- _
2.7
2.6
2.5
2.4
2.3
2.2
2.1
2
1.8
t 1.7
1.6
- 1.5 —
o
`c 1.4
• 1.3
IX 1.2
1.1
1 ,
0.9
0.8
0.7
0.4
0.3
0.2
0.1
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
8.5
8
7.5-
7
6.5
6-
5.5
5
w -
• 4.5-
c 4
z
3.5-
3-
2.5
1
0.5
.. . . .
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 002-Year Page 8
Subbasin:Sub-55
Input Data
Area(ac) 30.93
Peak Rate Factor 484
Weighted Curve Number 82.75
Rain Gage ID
Composite Curve Number
32 Area Soil Curve
Soil/Surface Description (acres) Group Number
>75%grass cover,Good 12.75 B 61
Paved parking&roofs 18.18 C 98
Composite Area&Weighted CN 30.93 82.75
Time ofConcentration
User-Defined TDC override(minutes):5.00
Subbasin Runoff Results
Total Rainfall(in) 3.5
Total Runoff(in) 1.84
Peak Runoff(cfs) 59.59
Weighted Curve Number 82.75
Time of Concentration(days hh:mm:ss) 0 00:05:00

Post-Development 002-Year Page 9
Subbasin:Sub-55
Rainfall Intensity Graph
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
s
• 1.7
1.6
8 1.5
c 1.4
ce 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 L I
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23
Time(hrs)
Runoff Hydrograph
62
60
58
56
54
52
50
48
46
44
42
40
38
- 36
wU 34
32
0 30
S 28
• 26
24
22
20
18
16
14
12
10
8
6
4
2
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 10
Pipe Input
SN Element Length Inlet Inlet Outlet Outlet Total Average Pipe Pipe Pipe Manning's Entrance Exit/Bend Additional Initial Flap No.of
ID Invert Invert Invert Invert Drop Slope Shape Diameter or Width Roughness Losses Losses Losses Flow Gate Barrels
Elevation Offset Elevation Offset Height
(It) (It) (ft) (8) (8) (It) (%) (m) (in) (cI)
1 Link-05 83.52 578.00 0.00 574.20 0.00 3.80 4.5500 CIRCULAR 30.000 30.000 0.0150 0.5000 0.5000 0.0000 0.00 No 1

Post-Development 002-Year Page 11
Pipe Results
SN Element Peak Time of Design Flow Peak Flow/ Peak Flow Trawl Peak Flow Peak Flow Total Tune 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) (mm) (ft) (mm)
1 L nk-05 46.43 0 00:00 75.83 0.61 15.46 0.09 0.43 0.78 0.00 Calculated

Post-Development 002-Year Page 12
Storage Nodes
Storage Node:Pond-06
Input Data
Invert Elevation(ft) 578.00
Max(Rim)Elevation(ft) 588.00
Max(Rim)Offs et(&) 10.00
Initial Water Elevation(ft) 582.50
Initial Water Depth(ft) 4.50
Ponded Area(ft2) 1.00
Evaporation less 0.00
Outflow Weirs
SN Element Weir Flap Crest Crest Length Weir Total Discharge
ID Type Gate Elevation Offset Height Coefficient
(ft) (ft) (ft) (ft)
1 EMER SPILLWAY05 Trapezoidal No 586.50 8.50 20.00 999.00 3.33
2 WEIR-05 Rectangular No 584.00 6.00 3.00 2.50 3.33
Outflow Orifices
SN Element Orifice Orifice Flap Circular Rectangular Rectangular Orifice Orifice
ID Type Shape Gate Orifice Orifice Orifice Invert Coefficient
Diameter Height Width Elevation
(m) (in) (m) (ft)
1 CS-RIM05 Bottom Rectangular No 60.00 60.00 586.50 0.63
2 Orifice-05 Side CIRCULAR No 4.00 582.50 0.61
Output Summary Results
Peak Inflow(cfs) 58.35
Peak Lateral Inflow(cfs) 58.35
PeakOutflow(cfs) 4.44
Peak Fxflltration Flow Rate(cfm) 0
MaxHGLElevation Attained(ft) 584.53
Max HGLDepth Attained(ft) 6.53
Average HGLElevation Attained(ft) 583.42
Average HGLDepth Attained(ft) 5.42
Time of MaxHGLOccurrence(days hh:mm) 0 14:01
Total Exfiltration Volume(1000-fl) 0
Total Flooded Volume(ac-in) 0
Total lime Flooded(min) 0
Total Retention lime(sec) 0

Post-Development 010-Year Page 1
Project Description
File Name 27842.0005-Post.SPF
Project Options
Flow Units CFS
Elevation Type Elevation
HydrologyMethod SCS TR 55
Time of Concentration('IOC)Ivvthod SCS TR 55
link Routing Ivlthod Hydrodynamic
Enable OwrflowPonding at Nodes YES
Skip Steady State Analysis Time Periods NO
Analysis Options
Start Analysis On 00:00:00 0:00:00
End Analysis On 00:00:00 0:00:00
Start Reporting On 00:00:00 0:00:00
Antecedent DryDays 0 days
Runoff(Dry Weather)Time Step 0 01:00:00 days hh:mm:ss
Runoff(Wet Weather)Tune Step 0 00:05:00 days hh:mm:ss
Reporting lime Step 0 00:05:00 days hh:mm:ss
Routing Time Step 1 seconds
Number of Elements
ety
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
Wens 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)
49 Time Series 1S-010 Intensity inches North Carolina Union 10.00 5.20 SCS Type uI24-hr

Post-Development 010-Year Page 2
Subbasin Summary
SN Subbasin Area PeakRate Weighted Total Total Total Peak Time of
ID Factor Curve Rainfall Runoff Runoff Runoff Concentration
Number Volume
(ac) (in) (in) (ac-in) (cfs) (days hh:mm:ss)
1 Sub-53 11.43 484.00 65.42 5.20 1.82 20.81 21.69 0 00:05:00
2 Sub-55 30.93 484.00 82.75 5.20 3.33 103.03 105.77 0 00:05:00

Post-Development 010-Year Page 3
Node Summary
SN Element Element Invert Ground/Rim Initial Surcharge Ponded Peak IvhxHGL Max Mn Time of Total Total lime
ID Type Elevation (Ivhx) Water Elevation Area Inflow Elevation Surcharge Freeboard Peak Flooded Flooded
Elevation Elevation Attained Depth .Attained Flooding Volume
Attained Occurrence
(It) (ft) (ft) (ft) (ft') (cfs) (0) (ft) (It) (days hh:mm) (ac-in) (min)
1 CS-05 Junction 578.00 586.50 582.50 999.00 1.00 20.17 582.49 0.00 4.01 0 00:00 0.00 0.00
2 Out-29 Outfall 574.20 46.43 575.61
3 Out-spillway-03 Outfall 574.20 0.00 574.20
4 Pond-06 Storage Node 578.00 588.00 582.50 1.00 104.36 585.56 0.00 0.00

Post-Development 010-Year Page 4
link Summary
SNElement Element From To(Outlet) Length Inlet Outlet Average Diameter or Mhnning'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
(0) (It) (It) (%) (in) (cfs) (cfs) (ft/sec) (6) (min)
1 L nk-05 Pipe CS-05 Out-29 83.52 578.00 574.20 4.5500 30.000 0.0150 46.43 75.83 0.61 15.46 0.97 0.78 0.00 Calculated
2 CS-RIM-05 Orifice Pond-06 CS-05 578.00 578.00 60.000 0.00
3 Orifice-05 Orifice Pond-06 CS-05 578.00 578.00 4.000 0.73
4 FMERSPILLWAY-05 Weir Pond-06 Out-spillway-03 578.00 574.20 0.00
5 WEIR-OS Weir Pond-06 CS-05 578.00 578.00 19.44

Post-Development 010-Year Page 5
Subbas in Hydrology
Subbasin:Sub-53
Input Data
Area(ac) 11.43
Peak Rate Factor 484
Weighted Curve Number 65.42
Rain Gage ID
Composite Curve Number
32 Area Soil Curve
Soil/Surface Description (acres) Group Number
>75%grass cover,Good 9.98 B 61
>75%grass cover,Good 0.17 D 80
Paved roads with curbs&sewers 1.28 A 98
Composite Area&Weighted CN 11.43 65.42
Time of Concentration
TOC Ivbthod:SCS TR 55
Sheet Flow Equation:
Tc=(0.007*((n*If)^0.8))/((P^0.5)*(SP0.4))
Where:
Tc=Time of Concentration(hr)
n =Ivfanning's roughness
If=Flow Length(ft)
P =2 yr,24 hr Rainfall(inches)
Sf=Slope(ft/ft)
Shallow Concentrated Flow Equation:
V=16.1345*(SP0.5)(unpaved surface)
V=20.3282*(Sf 0.5)(paved surface)
V=15.0*(SP0.5)(grassed waterway surface)
V=10.0*(Sf 0.5)(nearlybare&untilled surface)
V=9.0*(S1n0.5)(cultivated straight rows surface)
V=7.0*(S14.5)(short grass pasture surface)
V=5.0*(SP`0.5)(woodland surface)
V=2.5*(SP`0.5)(forest w/heavy litter surface)
Tc=(If/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))*(SP`0.5))/n
R=AI/Wp
Tc=(Lf/\ /(3600sec/hr)
Where:
Tc=Time of Concentration(hr)
Lf=Flow Length(ft)
R=Hydraulic Radius(ft)
Aq=Flow Area(ft2)
Wp=Wetted Perimeter(ft)
V=Velocity(ft/sec)
Sf=Slope(ft/ft)
n=Ivhnningsroughness
User-Defined TOC override(minutes):5
Subbasin RunoffRe sults
Total Rainfall(in) 5.2
Total Runoff(in) 1.82

Post-Development
010-Year Page 6
Peak Runoff(cfs) 21.69
Weighted Curve Number 65.42
Tune of Concentration(days hh:mm:ss) 0 00:05:00

Post-Development 010-Year Page 7
Subbasin:Sub-53
Rainfall Intensity Graph
4.4
4.2
4
3.8
3.6
3.4
3.2
3
2.8
2.6
c 2.4
m2.2
•
c 2
Ce 1.8
1.6
1.4
1.2
1
0.8
0.4
0.2-
O▪ 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
22
21-
20-
19
18
17
16
15
14
13
12
o
11
0
o 10
9
8
6
5-
4-
3
2
O 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 8
Subbasin:Sub-55
Input Data
Area(ac) 30.93
Peak Rate Factor 484
Weighted Curve Number 82.75
Rain Gage ID
Composite Curve Number
32 Area Soil Curve
Soil/Surface Description (acres) Group Number
>75%grass cover,Good 12.75 B 61
Paved parking&roofs 18.18 C 98
Composite Area&Weighted CN 30.93 82.75
Time ofConcentration
User-Defined TDC override(minutes):5.00
Subbasin Runoff Results
Total Rainfall(in) 5.2
Total Runoff(in) 3.33
Peak Runoff(cfs) 105.77
Weighted Curve Number 82.75
Time of Concentration(days hh:mm:ss) 0 00:05:00

Post-Development 010-Year Page 9
Subbasin:Sub-55
Rainfall Intensity Graph
4.6
4.4- _
4.2
4
3.8
3.6
3.4
3.2
3
2.8
t 2.6
c
2.4
m 2.2 . .
c
@ 2
1.8
1.6
1.4
1.2
1
0.8
0.6
0.4
-ram
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
110
105:
100-
95
90
85
80
75
70
65
U 60
55
0
S 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 010-Year Page 10
Pipe Input
SN Element Length Inlet Inlet Outlet Outlet Total Average Pipe Pipe Pipe Manning's Entrance Exit/Bend Additional Initial Flap No.of
ID Invert Invert Invert Invert Drop Slope Shape Diameter or Width Roughness Losses Losses Losses Flow Gate Barrels
Elevation Offset Elevation Offset Height
(It) (It) (ft) (8) (8) (It) (%) (m) (in) (cI)
1 Link-05 83.52 578.00 0.00 574.20 0.00 3.80 4.5500 CIRCULAR 30.000 30.000 0.0150 0.5000 0.5000 0.0000 0.00 No 1

Post-Development 010-Year Page 11
Pipe Results
SN Element Peak Time of Design Flow Peak Flow/ Peak Flow Trawl Peak Flow Peak Flow Total Tune 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) (mm) (ft) (mm)
1 L nk-05 46.43 0 00:00 75.83 0.61 15.46 0.09 0.97 0.78 0.00 Calculated

Post-Development 010-Year Page 12
Storage Nodes
Storage Node:Pond-06
Input Data
Invert Elevation(ft) 578.00
Max(Rim)Elevation(ft) 588.00
Max(Rim)Offs et(&) 10.00
Initial Water Elevation(ft) 582.50
Initial Water Depth(ft) 4.50
Ponded Area(ft2) 1.00
Evaporation less 0.00
Outflow Weirs
SN Element Weir Flap Crest Crest Length Weir Total Discharge
ID Type Gate Elevation Offset Height Coefficient
(ft) (ft) (ft) (ft)
1 EMER SPILLWAY05 Trapezoidal No 586.50 8.50 20.00 999.00 3.33
2 WEIR-05 Rectangular No 584.00 6.00 3.00 2.50 3.33
Outflow Orifices
SN Element Orifice Orifice Flap Circular Rectangular Rectangular Orifice Orifice
ID Type Shape Gate Orifice Orifice Orifice Invert Coefficient
Diameter Height Width Elevation
(m) (in) (m) (ft)
1 CS-RIM05 Bottom Rectangular No 60.00 60.00 586.50 0.63
2 Orifice-05 Side CIRCULAR No 4.00 582.50 0.61
Output Summary Results
Peak Inflow(cfs) 104.36
Peak Lateral Inflow(cfs) 104.36
PeakOutflow(cfs) 20.17
Peak Fxflltration Flow Rate(cfm) 0
MaxHGLElevation Attained(ft) 585.56
Max HGLDepth Attained(ft) 7.56
Average HGLElevation Attained(ft) 583.61
Average HGLDepth Attained(ft) 5.61
Time of MaxHGLOccurrence(days hh:mm) 0 12:37
Total Exfiltration Volume(1000-fl) 0
Total Flooded Volume(ac-in) 0
Total lime Flooded(min) 0
Total Retention Time(sec) 0

Post-Development 025-Year Page 1
Project Description
File Name 27842.0005-Post.SPF
Project Options
Flow Units CFS
Elevation Type Elevation
HydrologyMethod SCS TR 55
Time of Concentration('IOC)Ivvthod SCS TR 55
link Routing Ivlthod Hydrodynamic
Enable OwrflowPonding at Nodes YES
Skip Steady State Analysis Time Periods NO
Analysis Options
Start Analysis On 00:00:00 0:00:00
End Analysis On 00:00:00 0:00:00
Start Reporting On 00:00:00 0:00:00
Antecedent DryDays 0 days
Runoff(Dry Weather)Time Step 0 01:00:00 days hh:mm:ss
Runoff(Wet Weather)Tune Step 0 00:05:00 days hh:mm:ss
Reporting lime Step 0 00:05:00 days hh:mm:ss
Routing Time Step 1 seconds
Number of Elements
ety
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
Wens 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)
49 Time Series 1S-025 Intensity inches North Carolina Union 25.00 6.10 SCS Type uI24-hr

Post-Development 025-Year Page 2
Subbasin Summary
SN Subbasin Area PeakRate Weighted Total Total Total Peak Time of
ID Factor Curve Rainfall Runoff Runoff Runoff Concentration
Number Volume
(ac) (in) (in) (ac-in) (cfs) (days hh:mm:ss)
1 Sub-53 11.43 484.00 65.42 6.10 2.46 28.15 29.56 0 00:05:00
2 Sub-55 30.93 484.00 82.75 6.10 4.16 128.61 130.56 0 00:05:00

Post-Development 025-Year Page 3
Node Summary
SN Element Element Invert Ground/Rim Initial Surcharge Ponded Peak IvhxHGL Max Mn Time of Total Total lime
ID Type Elevation (Ivhx) Water Elevation Area Inflow Elevation Surcharge Freeboard Peak Flooded Flooded
Elevation Elevation Attained Depth .Attained Flooding Volume
Attained Occurrence
(It) (fl) (fl) (fl) (It) (cfs) (0) (ft) (It) (days hh:mm) (ac-in) (min)
1 CS-05 Junction 578.00 586.50 582.50 999.00 1.00 31.68 582.49 0.00 4.01 0 00:00 0.00 0.00
2 Out-29 Outfall 574.20 46.43 575.61
3 Out-spillway-03 Outfall 574.20 0.00 574.20
4 Pond-06 Storage Node 578.00 588.00 582.50 1.00 129.12 586.12 0.00 0.00

Post-Development 025-Year Page 4
link Summary
SNElement 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
(8) (It) (It) (%) (in) (cfs) (cfs) (ft/sec) (6) (min)
1 L nk-05 Pipe CS-05 Out-29 83.52 578.00 574.20 4.5500 30.000 0.0150 46.43 75.83 0.61 15.46 1.28 0.78 0.00 Calculated
2 CS-RIM-05 Orifice Pond-06 CS-05 578.00 578.00 60.000 0.00
3 Orifice-05 Orifice Pond-06 CS-05 578.00 578.00 4.000 0.80
4 FMERSPILLWAY-05 Weir Pond-06 Out-spillway-03 578.00 574.20 0.00
5 WEIR-OS Weir Pond-06 CS-05 578.00 578.00 30.88

Post-Development 025-Year Page 5
Subbas in Hydrology
Subbasin:Sub-53
Input Data
Area(ac) 11.43
Peak Rate Factor 484
Weighted Curve Number 65.42
Rain Gage ID
Composite Curve Number
32 Area Soil Curve
Soil/Surface Description (acres) Group Number
>75%grass cover,Good 9.98 B 61
>75%grass cover,Good 0.17 D 80
Paved roads with curbs&sewers 1.28 A 98
Composite Area&Weighted CN 11.43 65.42
Time of Concentration
TOC Ivbthod:SCS TR 55
Sheet Flow Equation:
Tc=(0.007*((n*If)^0.8))/((P^0.5)*(SP0.4))
Where:
Tc=Time of Concentration(hr)
n =Ivfanning's roughness
If=Flow Length(ft)
P =2 yr,24 hr Rainfall(inches)
Sf=Slope(ft/ft)
Shallow Concentrated Flow Equation:
V=16.1345*(SP0.5)(unpaved surface)
V=20.3282*(Sf 0.5)(paved surface)
V=15.0*(SP0.5)(grassed waterway surface)
V=10.0*(Sf 0.5)(nearlybare&untitled surface)
V=9.0*(S1n0.5)(cultivated straight rows surface)
V=7.0*(S14.5)(short grass pasture surface)
V=5.0*(Sf`0.5)(woodland surface)
V=2.5*(SP`0.5)(forest w/heavy litter surface)
Tc=(If/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))*(SP`0.5))/n
R=AI/Wp
Tc=(Lf/\ /(3600sec/hr)
Where:
Tc=Time of Concentration(hr)
Lf=Flow Length(ft)
R=Hydraulic Radius(ft)
Aq=Flow Area(ft5)
Wp=Wetted Perimeter(ft)
V=Velocity(ft/sec)
Sf=Slope(ft/ft)
n=Ivhnningsroughness
User-Defined TOC override(minutes):5
Subbasin RunoffRe sults
Total Rainfall(in) 6.1
Total Runoff(in) 2.46

Post-Development
025-Year Page 6
Peak Runoff(cfs) 29.56
Weighted Curve Number 65.42
Tune of Concentration(days hh:mm:ss) 0 00:05:00

Post-Development 025-Year Page 7
Subbasin:Sub-53
Rainfall Intensity Graph
5.2
5
4.8
4.6
4.4
4.2
4
3.8
3.6
3.4
3.2
s 3
c 2.8
2.6 -
2.4
2.2
2 -
1.8 -
1.6
1.4 -
1.2
1
0.8
0.4
0.2.
O▪ 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
31
30
29
28
27
26
25
24
23
22
21
20
19
- 18 -
U• 17 —
`-' 16
0 15
c 14
• 13
12
11
10
9
8
7
6
5
4
3
2
1
O 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 8
Subbasin:Sub-55
Input Data
Area(ac) 30.93
Peak Rate Factor 484
Weighted Curve Number 82.75
Rain Gage ID
Composite Curve Number
32 Area Soil Curve
Soil/Surface Description (acres) Group Number
>75%grass cover,Good 12.75 B 61
Paved parking&roofs 18.18 C 98
Composite Area&Weighted CN 30.93 82.75
Time ofConcentration
User-Defined TDC override(minutes):5.00
Subbasin Runoff Results
Total Rainfall(in) 6.1
Total Runoff(in) 4.16
Peak Runoff(cfs) 130.56
Weighted Curve Number 82.75
Time of Concentration(days hh:mm:ss) 0 00:05:00

Post-Development 025-Year Page 9
Subbasin:Sub-55
Rainfall Intensity Graph
5.4
5.2
5
4.8
4.6 -
4.4
4.2
4 -
3.8
3.6 —
3.4
3.2
-c 3
c
2.8
m 2.6
2.4
Ce 2.2
2
1.8
1.6
1.4 —
1.2
1
0.6
0.2
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
135
130-
125
120
115
110
105
100
95
90
85
80
. 75
• 70
0 65
, •
K• 60
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 025-Year Page 10
Pipe Input
SN Element Length Inlet Inlet Outlet Outlet Total Average Pipe Pipe Pipe Manning's Entrance Exit/Bend Additional Initial Flap No.of
ID Invert Invert Invert Invert Drop Slope Shape Diameter or Width Roughness Losses Losses Losses Flow Gate Barrels
Elevation Offset Elevation Offset Height
(It) (It) (ft) (8) (8) (It) (%) (m) (in) (cI)
1 Link-05 83.52 578.00 0.00 574.20 0.00 3.80 4.5500 CIRCULAR 30.000 30.000 0.0150 0.5000 0.5000 0.0000 0.00 No 1

Post-Development 025-Year Page 11
Pipe Results
SN Element Peak Time of Design Flow Peak Flow/ Peak Flow Trawl Peak Flow Peak Flow Total Tune 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) (mm) (ft) (mm)
1 L nk-05 46.43 0 00:00 75.83 0.61 15.46 0.09 1.28 0.78 0.00 Calculated

Post-Development 025-Year Page 12
Storage Nodes
Storage Node:Pond-06
Input Data
Invert Elevation(ft) 578.00
Max(Rim)Elevation(ft) 588.00
Max(Rim)Offs et(&) 10.00
Initial Water Elevation(ft) 582.50
Initial Water Depth(ft) 4.50
Ponded Area(ft2) 1.00
Evaporation less 0.00
Outflow Weirs
SN Element Weir Flap Crest Crest Length Weir Total Discharge
ID Type Gate Elevation Offset Height Coefficient
(ft) (ft) (ft) (ft)
1 EMER SPILLWAY05 Trapezoidal No 586.50 8.50 20.00 999.00 3.33
2 WEIR-05 Rectangular No 584.00 6.00 3.00 2.50 3.33
Outflow Orifices
SN Element Orifice Orifice Flap Circular Rectangular Rectangular Orifice Orifice
ID Type Shape Gate Orifice Orifice Orifice Invert Coefficient
Diameter Height Width Elevation
(m) (in) (m) (ft)
1 CS-RIM05 Bottom Rectangular No 60.00 60.00 586.50 0.63
2 Orifice-05 Side CIRCULAR No 4.00 582.50 0.61
Output Summary Results
Peak Inflow(cfs) 129.12
Peak Lateral Inflow(cfs) 129.12
PeakOutflow(cfs) 31.68
Peak Fxflltration Flow Rate(cfm) 0
Max HGLElevation Attained(ft) 586.12
Max HGLDepth Attained(ft) 8.12
Average HGLElevation Attained(ft) 583.71
Average HGLDepth Attained(ft) 5.71
Time of MaxHGLOccurrence(days hh:mm) 0 12:34
Total Exfiltration Volume(1000-fl) 0
Total Flooded Volume(ac-in) 0
Total lime Flooded(min) 0
Total Retention Time(sec) 0

Post-Development 050-Year Page 1
Project Description
File Name 27842.0005-Post.SPF
Project Options
Flow Units CFS
Elevation Type Elevation
HydrologyMethod SCS TR 55
Time of Concentration('IOC)Ivvthod SCS TR 55
link Routing Ivlthod Hydrodynamic
Enable OwrflowPonding at Nodes YES
Skip Steady State Analysis Time Periods NO
Analysis Options
Start Analysis On 00:00:00 0:00:00
End Analysis On 00:00:00 0:00:00
Start Reporting On 00:00:00 0:00:00
Antecedent DryDays 0 days
Runoff(Dry Weather)Time Step 0 01:00:00 days hh:mm:ss
Runoff(Wet Weather)Tune Step 0 00:05:00 days hh:mm:ss
Reporting lime Step 0 00:05:00 days hh:mm:ss
Routing Time Step 1 seconds
Number of Elements
ety
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
Wens 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)
49 Time Series 1S-050 Intensity inches North Carolina Union 50.00 6.90 SCS Type uI24-hr

Post-Development 050-Year Page 2
Subbasin Summary
SN Subbasin Area PeakRate Weighted Total Total Total Peak Time of
ID Factor Curve Rainfall Runoff Runoff Runoff Concentration
Number Volume
(ac) (in) (in) (ac-in) (cfs) (days hh:mm:ss)
1 Sub-53 11.43 484.00 65.42 6.90 3.07 35.08 36.88 0 00:05:00
2 Sub-55 30.93 484.00 82.75 6.90 4.91 151.74 152.72 0 00:05:00

Post-Development 050-Year Page 3
Node Summary
SN Element Element Invert Ground/Rim Initial Surcharge Ponded Peak IvhxHGL Max Mn Time of Total Total lime
ID Type Elevation (Ivhx) Water Elevation Area Inflow Elevation Surcharge Freeboard Peak Flooded Flooded
Elevation Elevation Attained Depth .Attained Flooding Volume
Attained Occurrence
(It) (ft) (ft) (ft) (ft') (cfs) (0) (ft) (It) (days hh:mm) (ac-in) (min)
1 CS-05 Junction 578.00 586.50 582.50 999.00 1.00 43.16 582.49 0.00 4.01 0 00:00 0.00 0.00
2 Out-29 Outfall 574.20 59.65 575.61
3 Out-spillway-03 Outfall 574.20 1.57 574.20
4 Pond-06 Storage Node 578.00 588.00 582.50 1.00 151.24 586.58 0.00 0.00

Post-Development 050-Year Page 4
link Summary
SNElement 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
(0) (It) (It) (%) (in) (cfs) (cfs) (ft/sec) (6) (min)
1 L nk-05 Pipe CS-05 Out-29 83.52 578.00 574.20 4.5500 30.000 0.0150 46.43 75.83 0.61 15.46 1.58 0.78 0.00 Calculated
2 CS-RIM-05 Orifice Pond-06 CS-05 578.00 578.00 60.000 1.55
3 Orifice-05 Orifice Pond-06 CS-05 578.00 578.00 4.000 0.85
4 ElMIERSPILLWAY-05 Weir Pond-06 Out-spillway-03 578.00 574.20 1.57
5 WEIR-OS Weir Pond-06 CS-05 578.00 578.00 40.76

Post-Development 050-Year Page 5
Subbas in Hydrology
Subbasin:Sub-53
Input Data
Area(ac) 11.43
Peak Rate Factor 484
Weighted Curve Number 65.42
Rain Gage ID
Composite Curve Number
32 Area Soil Curve
Soil/Surface Description (acres) Group Number
>75%grass cover,Good 9.98 B 61
>75%grass cover,Good 0.17 D 80
Paved roads with curbs&sewers 1.28 A 98
Composite Area&Weighted CN 11.43 65.42
Time of Concentration
TOC Ivbthod:SCS TR 55
Sheet Flow Equation:
Tc=(0.007*((n*If)^0.8))/((P^0.5)*(SP0.4))
Where:
Tc=Time of Concentration(hr)
n =Ivfanning's roughness
If=Flow Length(ft)
P =2 yr,24 hr Rainfall(inches)
Sf=Slope(ft/ft)
Shallow Concentrated Flow Equation:
V=16.1345*(SP0.5)(unpaved surface)
V=20.3282*(Sf 0.5)(paved surface)
V=15.0*(SP0.5)(grassed waterway surface)
V=10.0*(Sf 0.5)(nearlybare&untitled surface)
V=9.0*(S1n0.5)(cultivated straight rows surface)
V=7.0*(S14.5)(short grass pasture surface)
V=5.0*(Sf`0.5)(woodland surface)
V=2.5*(SP`0.5)(forest w/heavy litter surface)
Tc=(If/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))*(SP`0.5))/n
R=AI/Wp
Tc=(Lf/\ /(3600sec/hr)
Where:
Tc=Time of Concentration(hr)
Lf=Flow Length(ft)
R=Hydraulic Radius(ft)
Aq=Flow Area(ft5)
Wp=Wetted Perimeter(ft)
V=Velocity(ft/sec)
Sf=Slope(ft/ft)
n=Ivhnningsroughness
User-Defined TOC override(minutes):5
Subbasin RunoffRe sults
Total Rainfall(in) 6.9
Total Runoff(in) 3.07

Post-Development 050-Year Page 6
Peak Runoff(cfs) 36.88
Weighted Curve Number 65.42
Tune of Concentration(days hh:mm:ss) 0 00:05:00

Post-Development 050-Year Page 7
Subbasin:Sub-53
Rainfall Intensity Graph
6
5.8-
5.6-
5.4
5.2
5
4.8
4.6
4.4
4.2
4
3.8 3.6
t 3.4
• 3.2
3
▪ 2.8
• 2.6
IX 2.4
2.2
2
1.8
1.6
1.4
0.8
0.6
0.4
0.2
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
38
36
34
32-
30-
28-
26-
24-
- 22
w
20
18-
z
K 16-
14-
12
10
8
6
4
2
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 8
Subbasin:Sub-55
Input Data
Area(ac) 30.93
Peak Rate Factor 484
Weighted Curve Number 82.75
Rain Gage ID
Composite Curve Number
32 Area Soil Curve
Soil/Surface Description (acres) Group Number
>75%grass cover,Good 12.75 B 61
Paved parking&roofs 18.18 C 98
Composite Area&Weighted CN 30.93 82.75
Time ofConcentration
User-Defined TDC override(minutes):5.00
Subbasin Runoff Results
Total Rainfall(in) 6.9
Total Runoff(in) 4.91
Peak Runoff(cfs) 152.72
Weighted Curve Number 82.75
Time of Concentration(days hh:mm:ss) 0 00:05:00

Post-Development 050-Year Page 9
Subbasin:Sub-55
Rainfall Intensity Graph
6.2
6 — - —
5.8 1
5.6_-
5.4
5.2
5
4.8
4.6
4.4
3.8
3.6
s
3.4
3.2
m 3
c 2.8
ce 2.6
2.4
2.2
2
1.8
1.6
1.4
1.2
1
0.8
0.6
0.4
O▪ 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
170
160
150
140
130
120-
110 -
100
w -
46 90 -
c 80
z
70
60
50
40
30
20
10
O 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 10
Pipe Input
SN Element Length Inlet Inlet Outlet Outlet Total Average Pipe Pipe Pipe Manning's Entrance Exit/Bend Additional Initial Flap No.of
ID Invert Invert Invert Invert Drop Slope Shape Diameter or Width Roughness Losses Losses Losses Flow Gate Barrels
Elevation Offset Elevation Offset Height
(It) (It) (ft) (8) (8) (It) (%) (m) (in) (cI)
1 Link-05 83.52 578.00 0.00 574.20 0.00 3.80 4.5500 CIRCULAR 30.000 30.000 0.0150 0.5000 0.5000 0.0000 0.00 No 1

Post-Development 050-Year Page 11
Pipe Results
SN Element Peak Time of Design Flow Peak Flow/ Peak Flow Trawl Peak Flow Peak Flow Total Tune 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) (mm) (ft) (mm)
1 L nk-05 46.43 0 00:00 75.83 0.61 15.46 0.09 1.58 0.78 0.00 Calculated

Post-Development 050-Year Page 12
Storage Nodes
Storage Node:Pond-06
Input Data
Invert Elevation(ft) 578.00
Max(Rim)Elevation(ft) 588.00
Max(Rim)Offs et(&) 10.00
Initial Water Elevation(ft) 582.50
Initial Water Depth(ft) 4.50
Ponded Area(ft2) 1.00
Evaporation less 0.00
Outflow Weirs
SN Element Weir Flap Crest Crest Length Weir Total Discharge
ID Type Gate Elevation Offset Height Coefficient
(ft) (ft) (ft) (ft)
1 EMER SPILLWAY05 Trapezoidal No 586.50 8.50 20.00 999.00 3.33
2 WEIR-05 Rectangular No 584.00 6.00 3.00 2.50 3.33
Outflow Orifices
SN Element Orifice Orifice Flap Circular Rectangular Rectangular Orifice Orifice
ID Type Shape Gate Orifice Orifice Orifice Invert Coefficient
Diameter Height Width Elevation
(m) (in) (m) (ft)
1 CS-RIM05 Bottom Rectangular No 60.00 60.00 586.50 0.63
2 Orifice-05 Side CIRCULAR No 4.00 582.50 0.61
Output Summary Results
Peak Inflow(cfs) 151.24
Peak Lateral Inflow(cfs) 151.24
PeakOutflow(cfs) 44.72
Peak Fxflltration Flow Rate(cfm) 0
MaxHGLElevation Attained(ft) 586.58
Max HGLDepth Attained(ft) 8.58
Average HGLElevation Attained(ft) 583.79
Average HGLDepth Attained(ft) 5.79
Time of MaxHGLOccurrence(days hh:mm) 0 12:31
Total Exfiltration Volume(1000-ft3) 0
Total Flooded Volume(ac-in) 0
Total lime Flooded(min) 0
Total Retention Time(sec) 0

Post-Development 100-Year Page 1
Project Description
File Name 27842.0005-Post.SPF
Project Options
Flow Units CFS
Elevation Type Elevation
HydrologyMethod SCS TR 55
Time of Concentration('IOC)Ivvthod SCS TR 55
link Routing Ivlthod Hydrodynamic
Enable OwrflowPonding at Nodes YES
Skip Steady State Analysis Time Periods NO
Analysis Options
Start Analysis On 00:00:00 0:00:00
End Analysis On 00:00:00 0:00:00
Start Reporting On 00:00:00 0:00:00
Antecedent DryDays 0 days
Runoff(Dry Weather)Time Step 0 01:00:00 days hh:mm:ss
Runoff(Wet Weather)Tune Step 0 00:05:00 days hh:mm:ss
Reporting lime Step 0 00:05:00 days hh:mm:ss
Routing Time Step 1 seconds
Number of Elements
ety
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
Wens 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)
49 Time Series 1S-100 Intensity inches North Carolina Union 100.00 7.50 SCS Type DI 24-hr

Post-Development 100-Year Page 2
Subbasin Summary
SN Subbasin Area PeakRate Weighted Total Total Total Peak Time of
ID Factor Curve Rainfall Runoff Runoff Runoff Concentration
Number Volume
(ac) (in) (in) (ac-in) (cfs) (days hh:mm:ss)
1 Sub-53 11.43 484.00 65.42 7.50 3.54 40.46 42.55 0 00:05:00
2 Sub-55 30.93 484.00 82.75 7.50 5.47 169.25 169.25 0 00:05:00

Post-Development 100-Year Page 3
Node Summary
SN Element Element Invert Ground/Rim Initial Surcharge Ponded Peak IvhxHGL Max Mn Time of Total Total lime
ID Type Elevation (Ivhx) Water Elevation Area Inflow Elevation Surcharge Freeboard Peak Flooded Flooded
Elevation Elevation Attained Depth .Attained Flooding Volume
Attained Occurrence
(It) (ft) (ft) (ft) (ft') (cfs) (0) (ft) (It) (days hh:mm) (ac-in) (min)
1 CS-05 Junction 578.00 586.50 582.50 999.00 1.00 55.14 582.49 0.00 4.01 0 00:00 0.00 0.00
2 Out-29 Outfall 574.20 74.47 575.78
3 Out-spillway-03 Outfall 574.20 10.80 574.20
4 Pond-06 Storage Node 578.00 588.00 582.50 1.00 167.76 586.79 0.00 0.00

Post-Development 100-Year Page 4
link Summary
SNElement Element From To(Outlet) Length Inlet Outlet Average Diameter or Munning'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
(8) (It) (It) (%) (in) (cfs) (cfs) (ft/sec) (6) (min)
1 L nk-05 Pipe CS-05 Out-29 83.52 578.00 574.20 4.5500 30.000 0.0150 55.14 75.83 0.73 15.46 1.95 0.78 0.00 Calculated
2 CS-RIM-05 Orifice Pond-06 CS-05 578.00 578.00 60.000 10.42
3 Orifice-05 Orifice Pond-06 CS-05 578.00 578.00 4.000 0.87
4 ElMIERSPILLWAY-05 Weir Pond-06 Out-spillway-03 578.00 574.20 10.80
5 WEIR-OS Weir Pond-06 CS-05 578.00 578.00 43.84

Post-Development 100-Year Page 5
Subbas in Hydrology
Subbasin:Sub-53
Input Data
Area(ac) 11.43
Peak Rate Factor 484
Weighted Curve Number 65.42
Rain Gage ID
Composite Curve Number
32 Area Soil Curve
Soil/Surface Description (acres) Group Number
>75%grass cover,Good 9.98 B 61
>75%grass cover,Good 0.17 D 80
Paved roads with curbs&sewers 1.28 A 98
Composite Area&Weighted CN 11.43 65.42
Time of Concentration
TOC Ivbthod:SCS TR 55
Sheet Flow Equation:
Tc=(0.007*((n*If)^0.8))/((P^0.5)*(SP0.4))
Where:
Tc=Time of Concentration(hr)
n =Ivfanning's roughness
If=Flow Length(ft)
P =2 yr,24 hr Rainfall(inches)
Sf=Slope(ft/ft)
Shallow Concentrated Flow Equation:
V=16.1345*(SP0.5)(unpaved surface)
V=20.3282*(Sf 0.5)(paved surface)
V=15.0*(SP0.5)(grassed waterway surface)
V=10.0*(Sf 0.5)(nearlybare&untilled surface)
V=9.0*(S1n0.5)(cultivated straight rows surface)
V=7.0*(S14.5)(short grass pasture surface)
V=5.0*(SP`0.5)(woodland surface)
V=2.5*(SP`0.5)(forest w/heavy litter surface)
Tc=(If/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))*(SP`0.5))/n
R=AI/Wp
Tc=(Lf/\ /(3600sec/hr)
Where:
Tc=Time of Concentration(hr)
Lf=Flow Length(ft)
R=Hydraulic Radius(ft)
Aq=Flow Area(ft2)
Wp=Wetted Perimeter(ft)
V=Velocity(ft/sec)
Sf=Slope(ft/ft)
n=Ivhnningsroughness
User-Defined TOC override(minutes):5
Subbasin RunoffRe sults
Total Rainfall(in) 7.5
Total Runoff(in) 3.54

Post-Development
100-Year Page 6
Peak Runoff(cfs) 42.55
Weighted Curve Number 65.42
Tune of Concentration(days hh:mm:ss) 0 00:05:00

Post-Development 100-Year Page 7
Subbasin:Sub-53
Rainfall Intensity Graph
6.5
6
5.5
5
4.5
4
c 3.5
m
3
2.5
2
1.5
0.5
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)
Runoff Hydrograph
44
42-
40-
38
36
34
32
30
28
26
U 24
22
o .
7 20
18
16-
14-
12
10-
8-
6
4
r
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 8
Subbasin:Sub-55
Input Data
Area(ac) 30.93
Peak Rate Factor 484
Weighted Curve Number 82.75
Rain Gage ID
Composite Curve Number
32 Area Soil Curve
Soil/Surface Description (acres) Group Number
>75%grass cover,Good 12.75 B 61
Paved parking&roofs 18.18 C 98
Composite Area&Weighted CN 30.93 82.75
Time ofConcentration
User-Defined TDC override(minutes):5.00
Subbasin Runoff Results
Total Rainfall(in) 7.5
Total Runoff(in) 5.47
Peak Runoff(cfs) 169.25
Weighted Curve Number 82.75
Time of Concentration(days hh:mm:ss) 0 00:05:00

Post-Development 100-Year Page 9
Subbasin:Sub-55
Rainfall Intensity Graph
7
6.5
6
5.5
5
4.5-
. 4-
c _
- 3.5
m
c
2.5
2
1.5
1
0.5
O• 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
180
170-
160
150
140
130
120
110
w 100
o
90
O
C
80
70
60
50
40
30 1l\
20
10
O 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 10
Pipe Input
SN Element Length Inlet Inlet Outlet Outlet Total Average Pipe Pipe Pipe Manning's Entrance Exit/Bend Additional Initial Flap No.of
ID Invert Invert Invert Invert Drop Slope Shape Diameter or Width Roughness Losses Losses Losses Flow Gate Barrels
Elevation Offset Elevation Offset Height
(It) (It) (ft) (8) (8) (It) (%) (m) (in) (cI)
1 Link-05 83.52 578.00 0.00 574.20 0.00 3.80 4.5500 CIRCULAR 30.000 30.000 0.0150 0.5000 0.5000 0.0000 0.00 No 1

Post-Development 100-Year Page 11
Pipe Results
SN Element Peak Time of Design Flow Peak Flow/ Peak Flow Trawl Peak Flow Peak Flow Total Tune 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) (mm) (ft) (mm)
1 L nk-05 55.14 0 12:26 75.83 0.73 15.46 0.09 1.95 0.78 0.00 Calculated

Post-Development 100-Year Page 12
Storage Nodes
Storage Node:Pond-06
Input Data
Invert Elevation(ft) 578.00
Max(Rim)Elevation(ft) 588.00
Max(Rim)Offs et(&) 10.00
Initial Water Elevation(ft) 582.50
Initial Water Depth(ft) 4.50
Ponded Area(02) 1.00
Evaporation less 0.00
Outflow Weirs
SN Element Weir Flap Crest Crest Length Weir Total Discharge
ID Type Gate Elevation Offset Height Coefficient
(ft) (ft) (ft) (ft)
1 EMER SPILLWAY05 Trapezoidal No 586.50 8.50 20.00 999.00 3.33
2 WEIR-05 Rectangular No 584.00 6.00 3.00 2.50 3.33
Outflow Orifices
SN Element Orifice Orifice Flap Circular Rectangular Rectangular Orifice Orifice
ID Type Shape Gate Orifice Orifice Orifice Invert Coefficient
Diameter Height Width Elevation
(m) (in) (m) (ft)
1 CS-RIM05 Bottom Rectangular No 60.00 60.00 586.50 0.63
2 Orifice-05 Side CIRCULAR No 4.00 582.50 0.61
Output Summary Results
Peak Inflow(cfs) 167.76
Peak Lateral Inflow(cfs) 167.76
PeakOutflow(cfs) 65.94
Peak Fxflltration Flow Rate(cfm) 0
Max HGLElevation Attained(ft) 586.79
Max HGLDepth Attained(ft) 8.79
Average HGLElevation Attained(ft) 583.84
Average HGLDepth Attained(ft) 5.84
Time of MaxHGLOccurrence(days hh:mm) 0 12:26
Total Exfiltration Volume(1000-fl) 0
Total Flooded Volume(ac-in) 0
Total lime Flooded(min) 0
Total Retention lime(sec) 0

25-YR
CAPACITY

HEC-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)
,16 I 586.12 586.12 585.83
15 25.1 586.32 586.12 0.13 586.45 586.25 2.9 586.56 594.13
14 24.3 586.71 586.33 587.83 586.55 2.9 588.09 593.14
13 23.4 588.23 587.88 589.55 588.30 2.8 589.80 595.29
12 21.4 589.91 589.62 593.62 591.61 3.0 593.62 598.91
11 20.3 593.72 593.46 0.09 593.81 593.54 3.2 593.97 598.84
10 19.1 594.07 593.83 0.06 594.12 593.89 3.3 594.24 598.46
9 17.2 594.32 594.13 600.74 598.28 3.3 600.74 604.06
8 15.2 600.80 600.65 605.26 602.95 3.1 605.26 608.18
7 11.6 605.34 605.13 0.05 605.39 605.18 3.1 605.51 609.05
6 7.7 605.54 605.45 0.03 605.58 605.48 2.9 605.60 609.05
5 7.4 605.71 605.44 0.82 606.54 606.26 2.3 606.63 614.29
94 6.9 606.72 606.49 0.90 607.63 607.39 1.9 607.78 613.65
4 3.2 607.82 607.71 0.22 608.03 607.93 1.6 608.09 615.63
3 2.5 608.11 608.05 0.04 608.16 608.09 1.5 608.20 615.63
2 1.5 608.21 608.19 0.03 608.24 608.22 1.2 608.27 618.37
1 1.0 608.28 608.27 608.28 608.10 1.0 608.28 618.37
95 2.9 607.81 607.73 0.06 607.87 607.78 1.9 607.96 613.65
56 3.2 605.55 605.44 608.07 606.90 1.6 608.07 611.03
55 1.8 608.08 608.05 0.02 608.10 608.07 1.5 608.12 611.02
39 2.2 605.28 605.23 0.04 605.32 605.27 1.4 605.35 608.70
40 1.4 600.75 600.73 0.01 600.77 600.74 1.9 600.78 604.06
41 1.4 594.29 594.17 594.67 594.39 0.7 594.67 598.46
42 0.7 590.85 590.73 0.18 591.03 590.91 0.6 591.13 595.29
79 586.12 586.12 582.79
77 66.4 586.39 586.12 0.10 586.49 586.22 8.5 586.65 595.80
32 64.7 586.75 586.50 0.23 586.98 586.72 7.8 587.06 595.03
31 77.8 587.21 586.84 0.24 587.45 587.08 7.8 587.78 598.01
30 78.4 587.93 587.55 0.24 588.17 587.79 7.7 588.49 599.05
29 67.5 588.67 588.22 0.72 589.38 588.93 7.3 589.70 597.99
28 50.7 590.02 589.22 0.21 590.23 589.43 4.9 590.52 597.99
27 49.3 591.15 589.58 0.49 591.64 590.07 5.8 592.27 596.91
87 47.1 592.84 591.41 1.59 594.43 593.00 5.7 595.04 598.77
73 15.0 595.10 594.95 0.06 595.16 595.02 5.6 595.20 598.34
72 12.8 595.24 595.13 0.10 595.33 595.23 5.3 595.37 600.55
76 9.9 595.39 595.33 0.11 595.50 595.44 4.5 595.52 598.32
71 7.8 595.56 595.46 0.14 595.70 595.60 4.2 595.72 595.98
75 6.7 595.81 595.59 0.24 596.06 595.83 4.2 596.12 596.58
70 4.7 596.21 595.98 0.63 596.83 596.61 4.4 596.91 597.98
69 2.3 596.93 596.88 0.15 597.08 597.03 4.0 597.11 599.17
26 33.0 595.32 594.62 0.56 595.88 595.17 6.2 596.10 600.09
25 30.2 596.33 595.74 0.59 596.92 596.33 6.7 597.27 601.33
24 11.9 597.36 597.14 0.08 597.44 597.21 6.8 597.56 601.33
23 11.3 597.64 597.44 0.05 597.69 597.48 7.0 597.79 602.38
22 9.3 597.96 597.53 600.05 598.64 2.2 600.05 604.12
21 5.7 600.12 599.96 602.45 601.36 1.7 602.45 606.01
96(5) 5.0 602.56 602.30 604.41 603.38 1.7 604.41 607.42
20 4.4 604.49 604.29 605.92 604.95 1.5 605.92 609.50
19 2.4 605.94 605.88 0.05 605.99 605.93 1.5 606.03 608.90
17 1.1 605.92 605.91 607.64 607.18 0.7 607.64 613.23
36 2.6 600.48 600.24 0.15 600.63 600.39 1.1 600.85 604.23
35 1.1 598.46 598.32 0.14 598.61 598.46 0.7 598.73 602.45
53 17.6 597.35 597.15 0.21 597.56 597.36 3.1 597.66 602.94
52 2.2 597.68 597.63 605.78 604.66 1.5 605.78 610.36
51 0.9 605.78 605.78 606.93 606.27 0.9 606.93 611.16
54 13.6 597.78 597.49 0.14 597.92 597.63 3.3 598.09 603.80
90 12.2 598.18 597.95 0.21 598.39 598.16 3.3 598.45 602.87
59 11.0 598.52 598.33 0.18 598.70 598.51 3.3 598.79 602.78
58 6.2 598.95 598.55 601.96 600.03 2.5 601.96 605.13
1T.1 THOMAS&HUTTON
T:\AutoCAD\Reports\HEC-22\HEC-22 Reporting

HEC-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)
57 2.7 601.99 601.91 606.74 605.52 1.6 606.74 612.35
60 2.4 598.81 598.75 604.95 603.78 1.5 604.95 610.53
34 2.6 596.12 596.05 0.05 596.17 596.10 5.8 596.23 600.09
50 2.0 592.29 592.25 0.03 592.31 592.27 3.3 592.35 596.91
68 16.9 589.72 589.67 0.06 589.78 589.73 6.3 589.82 590.25
67 16.0 589.88 589.72 0.05 589.94 589.77 5.7 590.02 590.25
66 14.9 590.08 589.93 0.07 590.15 590.00 4.9 590.22 592.48
80 13.1 590.33 590.06 595.76 593.13 3.4 595.76 598.42
81 11.3 595.84 595.64 596.87 595.73 2.0 596.87 600.79
65 9.3 597.05 596.62 599.55 598.52 2.0 599.61 602.90
64 7.1 599.71 599.46 602.09 601.18 1.7 602.09 605.58
63 4.0 602.16 602.00 604.89 604.21 1.3 604.89 608.61
62 1.6 604.90 604.87 609.33 608.77 0.9 609.33 612.97
45 11.2 590.21 589.17 592.57 591.53 2.5 592.99 596.78
89 3.9 593.06 592.90 594.78 594.14 1.3 594.78 598.60
88 1.6 594.79 594.77 0.03 594.82 594.79 1.0 595.25 598.93
47 3.8 593.06 592.89 0.18 593.24 592.97 1.4 593.45 596.78
46 1.6 594.57 594.28 594.93 594.64 0.7 594.93 599.05
33 1.5 591.17 590.79 593.28 592.90 0.8 593.28 597.21
1T.1 THOMAS&HUTTON
T:\AutoCAD\Reports\HEC-22\HEC-22 Reporting

HEC-22
Storm Drain Computations
Structure ID Length Drainage Runoff Tc Rain"I" Runoff Known Q Total Q Pipe Full Q Velocity Velocity Invert Elevation Slope
(ft) Area Coeff"C" (min) (in/hr) "Q" (cfs) (cfs) Dia. (cfs) Full Design
From To (ac) (cfs) (in) (ft/s) (ft/s) U/S D/S
�15 16 93 0.24 0.55 8 7.50 25.1 25.1 36' 74.5 10.54' 9.50 583.65 582.50 1.25%
14 15 140 0.26 0.55 8 7.56 24.3 24.3 30 43.3 8.82 9.07 585.21 583.65 1.11%
13 14 160 0.35 0.55 8 7.62 23.4 23.4 30 43.3 8.82 8.98 586.99 585.21 1.11%
12 13 162 0.27 0.55 8 7.68 21.4 21.4 30 61.2 12.47 11.36 590.59 586.99 2.22%
11 12 35 0.29 0.55 7 7.69 20.3 20.3 30 40.6 8.27 8.26 590.73 590.39 0.98%
10 11 27 0.17 0.55 7 7.71 19.1 19.1 30 38.7 7.88 7.85 590.98 590.73 0.89%
9 10 184 0.15 0.55 7 7.76 17.2 17.2 30 76.8 15.65 12.60 597.47 591.05 3.50%
8 9 135 0.36 0.55 7 7.80 15.2 15.2 30 76.8 15.65 12.18 602.20 597.47 3.50%
7 8 18 0.20 0.55 7 7.81 11.6 11.6 24 22.6 7.21 7.24 602.38 602.20 1.00%
6 7 28 0.09 0.55 7 7.83 7.7 7.7 24 22.6 7.21 6.52 602.66 602.38 1.00%
5 6 166 0.14 0.55 6 7.93 7.4 7.4 18 10.5 5.95 6.44 604.37 602.71 1.00%
94 5 209 0.24 0.50 6 8.07 6.9 6.9 18 8.8 4.98 5.51 605.84 604.38 0.70%
4 94 89 0.15 0.55 5 8.14 3.2 3.2 15 5.4 4.41 4.58 606.46 605.84 0.70%
3 4 28 0.22 0.55 5 8.17 2.5 2.5 15 5.4 4.41 4.32 606.66 606.46 0.70%
2 3 56 0.11 0.55 5 8.22 1.5 1.5 15 5.4 _4.41 3.80 607.05 606.66 0.70%
1 2 28 0.22 0.55 5 8.25 1.0 1.0 15 5.4 4.41 3.39 607.25 607.05 0.70%
95 94 28 0.69 0.50 5 8.25 2.9 2.9 15 5.4 4.41 4.47 606.04 605.84 0.70%
56 7 104 0.31 0.55 5 8.22 3.2 3.2 15 12.8 10.44 8.65 606.48 602.38 3.93%
55 56 28 0.39 0.55 5 8.25 1.8 1.8 15 4.6 3.73 3.49 606.62 606.48 0.50%
39 8 33 0.48 0.55 5 8.25 2.2 2.2 15 6.5 5.27 4.77 603.95 603.63 1.00%
40 9 28 0.32 0.55 5 8.25 1.4 1.4 15 14.5 11.78 7.53 598.87 597.47 5.00%
41 10 28 0.31 0.55 5 8.25 1.4 1.4 15 6.5 5.27 4.22 593.99 593.71 1.00%
42 13 36 0.16 0.55 5 8.25 0.7 0.7 15 4.6 3.73 2.75 590.57 590.39 0.50%
77 79 88 0.32 0.55 5 5.95 66.4 66.4 54 139.2 8.75 8.64 578.19 577.75 0.50%
32 77 211 0.44 0.55 5 5.99 64.7 64.7 544 139.2 8.75 8.59 579.25 578.19 0.50%
31 32 153 0.01 0.50 9 7.36 77.8 77.8 54 139.2 8.75 8.99 580.01 579.25 0.50%
30 31 151 0.13 0.55 9 7.43 78.4 78.4 54 139.2 8.75 9.01 580.77 580.01 0.50%
29 30 325 0.14 0.55 8 7.57 67.5 67.5 48 101.7 8.09 8.65 582.39 580.77 0.50%
28 29 36 0.34 0.55 8 7.62 50.7 50.7 36 103.5 14.65 14.56 585.63 584.76 2.41%
27 28 34 0.14 0.55 8 7.63 49.3 49.3 30 63.7 12.97 14.31 586.44 585.63 2.41%
87 27 120 0.07 0.55 8 7.66 47.1 47.1 30 63.7 12.97 14.19 589.33 586.44 2.41%
73 87 45 0.52 0.55 7 7.69 15.0 15.0 30 29.0 5.91 5.95 589.56 589.33 0.50%
72 73 97 0.73 0.55 7 7.76 12.8 12.8 30 29.0 5.91 5.73 590.04 589.56 0.50%
76 72 187 0.49 0.55 7 7.89 9.9 9.9 30 29.0 5.91 5.34 590.98 590.04 0.50%
71 76 119 0.26 0.55 6 7.98 7.8 7.8 24 16.0 5.10 5.06 591.57 590.98 0.50%
75 71 60 0.47 0.55 6 8.02 6.7 6.7 18 7.4 4.21 4.76 591.87 591.57 0.50%
70 75 121 0.54 0.55 6 8.13 4.7 4.7 15 4.6 3.73 4.24 592.48 591.87 0.50%
69 70 120 0.50 0.55 5 8.25 2.3 2.3 15 4.6 3.73 3.72 593.07 592.48 0.50%
26 87 86 0.12 0.55 6 7.92 33.0 33.0 30 33.3 6.78 7.72 589.90 589.33 0.66%
25 26 108 0.21 0.55 6 7.98 30.2 30.2 30 33.3 6.78 7.68 590.61 589.90 0.66%
24 25 28 0.14 0.55 6 8.00 11.9 11.9 24 16.0 5.10 5.58 590.75 590.61 0.50%
23 24 i 18 0.21 0.55 6 8.01 11.3 11.3 24 16.0 5.10 5.52 590.85 590.75 0.50%
IT.I THOMAS&HUTTON
T:\AutoCAolReports\HEC-221HEC-22 Reporting

HEC-22
Storm Drain Computations
Structure ID Length Drainage Runoff Tc Rain"I" Runoff Known Q Total Q Pipe Full Q Velocity Velocity Invert Elevation Slope
(ft) Area Coeff"C" (min) (in/hr) "Q" (cfs) (cfs) Dia. (cfs) Full Design
From To (ac) (cfs) (in) (ft/s) (ft/s) U/S D/S
'22 23 113 0.25 0.55 6 8.05 _9.3 9.3 18' 16.3 9.22' 9.52 597.83 595.13 2.40%
21 22 121 0.16 0.55 6 8.11 5.7 5.7 18 16.3 9.22 8.40 600.74 597.83 2.40%
96(5) 21 85 0.15 0.55 5 8.15 5.0 5.0 15 10.0 8.13 8.13 602.76 600.74 2.38%
20 96(5) 68 0.18 0.55 5 8.18 4.4 4.4 15 10.0 8.14 7.86 604.38 602.76 2.39%
19 20 33 0.53 0.55 5 8.25 2.4 2.4 15 4.6 3.73 3.77 604.54 604.38 0.50%
17 20 105 0.25 0.55 5 8.25 1.1 1.1 15 10.0 8.16 5.43 606.90 604.38 2.40%
36 22 29 0.57 0.55 5 8.25 2.6 2.6 15 4.7 3.83 3.93 599.72 599.57 0.53%
35 23 28 0.25 0.55 5 8.25 1.1 1.1 15 4.6 3.73 3.10 598.03 597.89 0.50%
53 25 113 0.41 0.55 6 8.05 17.6 17.6 30 29.0 5.91 6.19 594.57 594.00 0.50%
52 53 195 0.29 0.55 5 8.23 2.2 2.2 15 14.5 11.78 8.50 604.33 594.57 5.00%
51 52 35 0.19 0.55 5 8.25 0.9 0.9 15 14.5 11.78 6.51 606.07 604.33 5.00%
54 53 38 0.35 0.55 6 8.07 13.6 13.6 24 16.0 5.10 5.72 594.76 594.57 0.50%
90 54 74 0.26 0.55 6 8.12 12.2 12.2 24 16.0 5.10 5.60 595.12 594.76 0.50%
59 90 74 0.55 0.55 5 8.17 11.0 11.0 24 16.0 5.10 5.49 595.49 595.12 0.50%
58 59 83 0.78 0.55 5 8.20 6.2 6.2 15 14.1 11.51 11.13 599.45 595.49 4.77%
57 58 120 0.59 0.55 5 8.25 2.7 2.7 15 14.1 11.51 8.85 605.15 599.45 4.77%
60 59 160 0.52 0.55 5 8.25 2.4 2.4 15 14.4 11.75 8.67 603.44 595.49 4.98%
34 26 28 0.57 0.55 5 8.25 2.6 2.6 15 9.1 7.45 6.41 590.46 589.90 2.00%
50 27 28 0.43 0.55 5 8.25 2.0 2.0 15 4.6 3.73 3.58 589.08 588.94 0.50%
68 29 222 0.21 0.55 7 7.71 16.9 16.9 42 71.2 7.40 6.06 583.50 582.39 0.50%
67 68 36 0.25 0.55 7 7.72 16.0 16.0 30 61.3 12.48 10.49 584.30 583.50 2.23%
66 67 52 0.45 0.55 7 7.74 14.9 14.9 30 58.1 11.83 9.90 585.33 584.30 2.00%
80 66 158 0.44 0.55 7 7.78 13.1 13.1 24 48.0 15.29 13.01 592.41 585.33 4.50%
81 80 153 0.49 0.55 7 7.85 11.3 11.3 24 28.6 9.12 8.57 594.86 592.41 1.60%
65 81 171 0.51 0.55 6 7.93 9.3 9.3 18 13.3 7.53 8.13 597.60 594.86 1.60%
64 65 175 0.72 0.55 6 8.02 7.1 7.1 18 13.3 7.53 7.65 600.40 597.60 1.60%
63 64 200 0.54 0.55 6 8.13 4.0 4.0 15 8.2 6.67 6.61 603.59 600.40 1.60%
62 63 194 0.34 0.55 5 8.25 1.6 1.6 15 10.2 8.33 6.01 608.44 603.59 2.50%
45 30 157 0.79 0.55 6 8.10 11.2 11.2 18 12.9 7.29 8.20 590.45 588.09 1.50%
89 45 205 0.52 0.55 5 8.22 3.9 3.9 15 7.9 6.45 6.43 593.52 590.45 1.50%
88 89 48 0.34 0.55 5 8.25 1.6 1.6 15 7.9 6.45 5.01 594.24 593.52 1.50%
47 45 36 0.84 0.55 5 8.25 3.8 3.8 15 4.6 3.73 4.18 592.03 591.85 0.50%
46 30 36 0.35 0.55 5 8.25 1.6 1.6 15 6.5 5.27 4.37 594.21 593.85 1.00%
33 77 141 0.33 0.55 5 8.25 1.5 1.5 15 7.9 6.46 4.96 592.53 590.42 1.50%
IT.I THOMAS&HUTTON
T:\AutoCAolReports\HEC-221HEC-22 Reporting

4 IN/HR
INLET
SPREAD

HEC-22
Inlet Capacity Results
Structure Q=CIA/Kc Known Longitudinal Cross Cross Prey. Total Depth Gutter Spread Inlet Type Grate Grate Curb Curb Intercept Bypass Bypass Remark
(cfs) Q Slope Slope Slope Bypass Gutter d Width T Length Width Opening Opening Flow Flow Structure
(cfs) SL Sx Sw Flow Flow (ft) (ft) (ft) (in) (in) Length Height Qi Qb
(ft/ft) (ft/ft) (ft/ft) (cfs) (cfs) (in) (in) (cfs) (cfs)
94 0.5 -1.00 0.02 0.04 0.0 0.5, 0.1 2.0 1.9 Combination I 56.0 18.0 56.0 4.2 0.5_ _
95 1.4 -1.00 0.02 0.04 0.1 1.5 0.1 2.0 5.1 Combination 56.0 18.0 56.0 4.2 1.5
1 0.5 0.04 0.02 0.041 0.5 0.1 2.0 3.2 Combination 28.0 18.0 28.0 4.2 0.4 0.1 95
2 0.3 0.04 0.02 0.041 0.3 0.1 2.0 2.0 Combination 28.0 18.0 28.0 4.2 0.2 0.0 3
3 0.5 -1.00 0.02 0.04 0.0 0.5 0.1 2.0 2.4 Combination 28.0 18.0 28.0 4.2 0.5
4 0.3 0.03 0.02 0.04 0.3 0.1 2.0 2.8 Combination 28.0 18.0 28.0 4.2 0.3 0.0 94
5 0.3 0.02 0.02 0.04 0.3 0.1 2.0 2.7 Combination 28.0 18.0 28.0 4.2 0.3 0.0 8
6 0.2 -1.00 0.02 0.04 0.3 0.5 0.1 2.0 2.2 Combination 28.0 18.0 28.0 4.2 0.5
7 0.5 0.03 0.02 0.04 0.2 0.6 0.1 2.0 3.8 Combination 28.0 18.0 28.0 4.2 0.5 0.1 8
8 0.8 0.03 0.02 0.04 0.2 1.0 0.1 2.0 4.7 Combination 28.0 18.0 28.0 4.2 0.7 0.3 9
9 0.3 0.03 0.02 0.04 0.3 0.6 0.1 2.0 3.8 Combination 28.0 18.0 28.0 4.2 0.5 0.1 10
10 0.4 -1.00 0.02 0.04 0.1 0.5 0.1 2.0 2.4 Combination 28.0 18.0 28.0 4.2 0.5
11 0.7 0.02 0.02 0.04 0.7 0.1 2.0 4.2 Combination 28.0 18.0 28.0 4.2 0.5 0.2 42
12 0.6 0.02 0.02 0.04 0.6 0.1 2.0 4.1 Combination 28.0 18.0 28.0 4.2 0.5 0.1 13
13 0.8 0.02 0.02 0.04 0.1 0.9 0.1 2.0 4.9 Combination 28.0 18.0 28.0 4.2 0.7 0.3
14 0.6 0.40 0.13 0.6 0.0 2.0 2.3 Grate inlet 23.8 23.8 0.6 0.0
15 0.5 -1.00 0.05 0.5 0.1 2.0 3.8 Grate inlet 23.8 23.8 0.5
39 1.1 0.03 0.02 0.04 1.1 0.1 2.0 5.0 Combination 28.0 18.0 28.0 4.2 0.8 0.3 40
40 0.7 0.03 0.02 0.04 0.3 1.0 0.1 2.0 4.9 Combination 28.0 18.0 28.0 4.2 0.7 0.3 41
41 0.7 0.03 0.02 0.04 0.3 1.0 0.1 2.0 4.8 Combination 28.0 18.0 28.0 4.2 0.7 0.3 42
42 0.4 0.02 0.02 0.04 0.4 0.8 0.1 2.0 4.6 Combination 28.0 18.0 28.0 4.2 0.6 0.2
55 0.9 0.02 0.02 0.04 0.9 0.1 2.0 5.0 Combination 28.0 18.0 28.0 4.2 0.6 0.3 6
56 0.7 0.02 0.02 0.04 0.7 0.1 2.0 4.6 Combination 28.0 18.0 28.0 4.2 0.5 0.2 7
90 0.6 -1.00 0.29 0.6 0.1 2.0 2.3 Grate inlet 23.8 23.8 0.6
96(5) 0.3 0.02 0.02 0.04 0.3 0.1 2.0 2.9 Combination 28.0 18.0 28.0 4.2 0.3 0.0
17 0.6 0.04 0.02 0.04 0.6 0.1 2.0 3.4 Combination 28.0 18.0 28.0 4.2 0.5 0.1 20
19 1.2 0.03 0.02 0.04 1.2 0.1 2.0 4.9 Combination 28.0 18.0 28.0 4.2 0.8 0.4 36
20 0.4 0.04 0.02 0.04 0.1 0.5 0.1 2.0 3.2 Combination 28.0 18.0 28.0 4.2 0.4 0.1 21
21 0.4 0.02 0.02 0.04 0.1 0.4 0.1 2.0 3.7 Combination 28.0 18.0 28.0 4.2 0.4 0.1 22
22 0.6 0.02 0.02 0.04 0.1 0.6 0.1 2.0 4.5 Combination 28.0 18.0 28.0 4.2 0.5 0.2 23
23 0.5 0.02 0.02 0.04 0.2 0.6 0.1 2.0 4.4 Combination 28.0 18.0 28.0 4.2 0.5 0.2 24
24 0.3 0.01 0.02 0.04 0.3 0.7 0.1 2.0 4.7 Combination 28.0 18.0 28.0 4.2 0.5 0.2 25
25 0.5 0.01 0.02 0.04 0.5 0.9 0.2 2.0 6.1 Combination 28.0 18.0 28.0 4.2 0.6 0.3 26
26 0.3 0.02 0.02 0.04 0.3 0.6 0.1 2.0 4.3 Combination 28.0 18.0 28.0 4.2 0.5 0.1 87
27 0.3 0.02 0.02 0.04 0.0 0.3 0.1 2.0 3.2 Combination 28.0 18.0 28.0 4.2 0.3 0.0 28
28 0.8 0.04 0.02 0.04 0.0 0.8 0.1 2.0 4.0 Combination 28.0 18.0 28.0 4.2 0.6 0.2 67
29 0.3 0.04 0.02 0.04 0.3 0.1 2.0 2.3 Combination 28.0 18.0 28.0 4.2 0.3 0.0 68
30 0.3 0.03 0.02 0.04 0.3 0.1 2.0 2.6 Combination 28.0 18.0 28.0 4.2 0.3 0.0 45
11-1 THOMAS&HUTTON
T:\AutoCAolReports\HEC-221HEC-22 Reporting

HEC-22
Inlet Capacity Results
Structure Q=CIA/Kc Known Longitudinal Cross Cross Prey. Total Depth Gutter Spread Inlet Type Grate Grate Curb Curb Intercept Bypass Bypass Remark
(cfs) Q Slope Slope Slope Bypass Gutter d Width T Length Width Opening Opening Flow Flow Structure
(cfs) SL Sx Sw Flow Flow (ft) (ft) (ft) (in) (in) Length Height Qi Qb
(ft/ft) (ft/ft) (ft/ft) (cfs) (cfs) (in) (in) (cfs) (cfs)
'31 0.0 0.09 0.14 0.0 0.0 2.0 2.1 Grate inlet I 23.8 23.8 0.0 _
32 1.0 -1.00 1.0 0.1 2.0 352.1 Grate inlet 23.8 23.8 1.0
33 0.7 0.01 0.05 0.7 0.1 2.0 4.2 Grate inlet 23.8 23.8 0.6 0.2 77
34 1.3 0.02 0.02 0.04 0.5 1.7 0.2 2.0 6.9 Combination 28.0 18.0 28.0 4.2 1.0 0.7 50
35 0.6 0.02 0.02 0.04 0.7 1.2 0.2 2.0 6.0 Combination 28.0 18.0 28.0 4.2 0.8 0.5 34
36 1.3 0.02 0.02 0.04 0.4 1.6 0.2 2.0 6.8 Combination 28.0 18.0 28.0 4.2 1.0 0.7 35
45 1.8 -1.00 0.02 0.04 0.5 2.2 0.2 2.0 6.9 Combination 56.0 18.0 56.0 4.2 2.2
46 0.8 0.03 0.02 0.04 0.8 0.1 2.0 4.4 Combination 28.0 18.0 28.0 4.2 0.6 0.2 47
47 1.9 -1.00 0.02 0.04 0.4 2.3 0.2 2.0 7.0 Combination 56.0 18.0 56.0 4.2 2.3
50 1.0 0.02 0.02 0.04 0.7 1.7 0.2 2.0 6.9 Combination 28.0 18.0 28.0 4.2 1.0 0.7 67
51 0.4 0.04 0.02 0.04 0.4 0.1 2.0 2.8 Combination 28.0 18.0 28.0 4.2 0.4 0.1 54
52 0.6 0.04 0.02 0.04 0.6 0.1 2.0 3.5 Combination 28.0 18.0 28.0 4.2 0.5 0.1 53
53 0.9 0.03 0.02 0.04 0.1 1.0 0.1 2.0 4.7 Combination 28.0 18.0 28.0 4.2 0.7 0.3 25
54 0.8 0.04 0.02 0.04 0.1 0.8 0.1 2.0 4.1 Combination 28.0 18.0 28.0 4.2 0.6 0.2 24
57 1.3 0.07 0.01 1.3 0.1 2.0 6.9 Grate inlet 23.8 23.8 0.7 0.6 58
58 1.7 0.06 0.11 0.6 2.4 0.1 2.0 3.2 Grate inlet 23.8 23.8 2.0 0.4 59
59 1.2 0.01 0.07 1.2 2.4 0.2 2.0 4.9 Grate inlet 23.8 23.8 1.7 0.7 80
60 1.2 0.10 0.00 1.2 0.0 2.0 13.2 Grate inlet 23.8 23.8 0.4 0.8 59
62 0.8 0.02 0.00 0.8 0.0 2.0 33.9 Grate inlet 23.8 23.8 0.1 0.6 63
63 1.2 0.01 0.05 0.6 1.9 0.2 2.0 5.1 Grate inlet 23.8 23.8 1.3 0.6 64
64 1.6 0.03 0.05 0.6 2.2 0.1 2.0 4.9 Grate inlet 23.8 23.8 1.5 0.7 65
65 1.1 0.01 0.00 0.7 1.9 0.1 2.0 55.8 Grate inlet 23.8 23.8 0.2 1.7 81
66 1.0 0.13 0.05 1.9 2.9 0.1 2.0 4.1 Grate inlet 23.8 23.8 2.0 0.9 67
67 0.6 0.02 0.02 0.04 1.8 2.4 0.2 2.0 7.8 Combination 28.0 18.0 28.0 4.2 1.2 1.1
68 0.5 0.02 0.02 0.04 0.0 0.5 0.1 2.0 3.7 Combination 28.0 18.0 28.0 4.2 0.4 0.1
69 1.1 0.03 0.06 1.1 0.1 2.0 3.7 Grate inlet 23.8 23.8 0.9 0.2 70
70 1.2 0.01 0.01 0.2 1.4 0.1 2.0 13.1 Grate inlet 23.8 23.8 0.5 0.9 75
71 0.6 -1.00 0.08 1.0 1.5 0.2 2.0 4.3 Grate inlet 23.8 23.8 1.5
72 1.6 0.02 0.13 1.6 0.2 2.0 3.2 Grate inlet 23.8 23.8 1.4 0.2 73
73 1.2 -1.00 0.13 0.2 1.4 0.2 2.0 3.4 Grate inlet 23.8 23.8 1.4
75 1.0 0.02 0.05 0.9 2.0 0.1 2.0 4.7 Grate inlet 23.8 23.8 1.4 0.6 71
76 1.1 0.05 0.03 1.1 0.1 2.0 4.7 Grate inlet 23.8 23.8 0.7 0.4 71
77 0.7 -1.00 0.2 0.9 0.1 2.0 326.8 Grate inlet 23.8 23.8 0.9
80 1.0 0.02 0.00 1.3 2.3 0.1 2.0 33.5 Grate inlet 23.8 23.8 0.4 1.9 66
81 1.1 0.02 0.12 1.7 2.7 0.2 2.0 3.8 Grate inlet 23.8 23.8 2.2 0.6 80
87 0.1 0.02 0.02 0.04 0.1 0.3 0.1 2.0 2.9 Combination 28.0 18.0 28.0 4.2 0.3 0.0 27
88 0.8 0.01 0.02 0.04 0.8 0.2 2.0 5.2 Combination 28.0 18.0 28.0 4.2 0.5 0.2 47
89 1.2 0.01 0.02 0.04 1.2 0.2 2.0 6.3 Combination 28.0 18.0 28.0 4.2 0.7 0.4 45
IA THOMAS&HUTTON
T:\AutoCADlReports\HEC-22kHEC-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"
42" 90
48" 120
54" 160
60" 200
66" 250
(1) CONCRETE PIPE
(2) CAPACITY (c.f.i.) BASED ON INLET CONTROL
FOR MAXIMUM DEPTH IN STANDARD CATCH BASIN
6/90

RIP RAP
APRON
DESIGN

Rip Rap Apron Design
Project Name: Cresswind PH5-FES-16
Drainage Specialist: DAC Date: May 30, 2024
Checked By: MSK Date: May 30, 2024
Step 1. Determine the tailwater depth from the channel characteristics below the pipe outlet for the
design capacity of the pipe. If the tailwater depth is less than half the outlet pipe diameter, it
is classifies as minimum tailwater conditions. If the tailwater is greater than half the pipe
diameter, it is classified as maximum tailwater conditions. Pipes that outlet onto wide flat
areas with no defined channel are assumed to have a minimum tailwater condition unless
reliable flood stage elevations show otherwise.
Rational Method for Flow
Total Drainage Area(Acres): 8.5
Outlet pipe diameter,Do(in.) 36
Tailwater depth(Feet) 0.5
Tailwater Method To Be Used Min TW(Fig.8.06a)
Discharge(cfs) 21.9
Velocity(ft./s) 9.1
Step 2. Based on the tailwater conditions determined in Step 1, enter Figure 8.06a or Figure 8.06b
and determine the d50 rip rap size and minimum apron length(La). The d50 size is the median
stone size in a well-graded rip rap apron.
Step 3. Determine the apron width at the pipe outlet,the apron shape, and the apron width at the
outlet end from the same figure used in Step 2.
Minimum TW Maximum TW
Riprap d50, (ft.) 0.6
Minimum apron length, La(ft.) ** 20
Apron width at pipe outlet(ft.) 9
Apron shape W=Do+La
Apron width at outlet end(ft.) 23
**-Minimum Apron Length Is 10 Feet per CLDS 20.23
Step 4. Determine the maximum Stone Diameter. D.= 1.5 X d50
Determine the Apron Thickness,Ta= 1.5 X d,nax
Minimum TW Maximum TW
Max Stone Diameter, dmax(Inches): 11
Apron Thickness (Inches): 16 71=
**-Minimum Apron Thickness Is 10 Inches per CLDS 20.23
Step 5. Fit the rip rap apron to the site by making it level for the minimum length La. Extend the
apron farther downstream and along the channel banks until stability is assured. Keep apron
as straight as possible and align it with the flow of the receiving stream. Make any necessary
alignment bends near the pipe outlet so that the entrance into the receiving stream is straight.
Some locations may require lining of the entire channel cross section to assure stability. It
may be necessary to increase the size of the rip rap where protection of the channel side
slopes is necessary. Where overfalls exist at pipe outlets or flows are excessive, a plunge pool
should be considered.

Figure 8.06a: Design of outlet protection from a round pipe flowing full, minimum
tailwater condition (Tw<0.5 diameter)
I_
IOutlet }
�JI1I 1
•
•
pipe i
�- .r .. 1 • : Nri diameter (Do) `I : �grs� ater < 0. 5Do ogliem
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II 0
3 5 10 20 5'.) 100 200 500 1000
Discharge (ft3/sec)
Curves may not be extrapolated.
Figure 8.06a Design of outlet protection protection from a round pipe flowing full, minimum tailwater condition (Tw < 0.5 diameter)
Rev. 1: 93 8.063

Rip Rap Apron Design
Project Name: Cresswind PH5-FES-79
Drainage Specialist: DAC Date: May 30, 2024
Checked By: MSK Date: May 30, 2024
Step 1. Determine the tailwater depth from the channel characteristics below the pipe outlet for the
design capacity of the pipe. If the tailwater depth is less than half the outlet pipe diameter, it
is classifies as minimum tailwater conditions. If the tailwater is greater than half the pipe
diameter, it is classified as maximum tailwater conditions. Pipes that outlet onto wide flat
areas with no defined channel are assumed to have a minimum tailwater condition unless
reliable flood stage elevations show otherwise.
Rational Method for Flow
Total Drainage Area(Acres): 22.4
Outlet pipe diameter,Do(in.) 54
Tailwater depth(Feet) 0.5
Tailwater Method To Be Used Min TW(Fig.8.06a)
Discharge(cfs) 70.1
Velocity(ft./s) 8.7
Step 2. Based on the tailwater conditions determined in Step 1, enter Figure 8.06a or Figure 8.06b
and determine the d50 rip rap size and minimum apron length(La). The d50 size is the median
stone size in a well-graded rip rap apron.
Step 3. Determine the apron width at the pipe outlet,the apron shape, and the apron width at the
outlet end from the same figure used in Step 2.
Minimum TW Maximum TW
Riprap d50, (ft.) 0.9
Minimum apron length, La(ft.) ** 28
Apron width at pipe outlet(ft.) 14
Apron shape W=Do+La
Apron width at outlet end(ft.) 33
**-Minimum Apron Length Is 10 Feet per CLDS 20.23
Step 4. Determine the maximum Stone Diameter. D.= 1.5 X d50
Determine the Apron Thickness,Ta= 1.5 X d,nax
Minimum TW Maximum TW
Max Stone Diameter, dmax(Inches): 16
Apron Thickness (Inches): 24 71=
**-Minimum Apron Thickness Is 10 Inches per CLDS 20.23
Step 5. Fit the rip rap apron to the site by making it level for the minimum length La. Extend the
apron farther downstream and along the channel banks until stability is assured. Keep apron
as straight as possible and align it with the flow of the receiving stream. Make any necessary
alignment bends near the pipe outlet so that the entrance into the receiving stream is straight.
Some locations may require lining of the entire channel cross section to assure stability. It
may be necessary to increase the size of the rip rap where protection of the channel side
slopes is necessary. Where overfalls exist at pipe outlets or flows are excessive, a plunge pool
should be considered.

Figure 8.06a: Design of outlet protection from a round pipe flowing full, minimum
tailwater condition (Tw<0.5 diameter)
} 1
I Outlet _ .
j •
W ■ Do + a . 1 ::....:.. .1. .. .
pipe r - , ..., . ; -; .9 -r
diameter (Do) - , . . : ::. .:.. ..11/A
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pp. * I • AA* .. ..
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0
3 5 10 20 59 100 200 500 1000
Discharge (ft3/sec)
Curves may not be extrapolated.
Figure 8.06a Design of outlet protection protection from a round pipe flowing full, minimum tailwater condition (Tw < 0.5 diameter)
Rev. 1: 93 8.063

Rip Rap Apron Design
Project Name: Cresswind PH5-FES-93
Drainage Specialist: DAC Date: May 30, 2024
Checked By: MSK Date: May 30, 2024
Step 1. Determine the tailwater depth from the channel characteristics below the pipe outlet for the
design capacity of the pipe. If the tailwater depth is less than half the outlet pipe diameter, it
is classifies as minimum tailwater conditions. If the tailwater is greater than half the pipe
diameter, it is classified as maximum tailwater conditions. Pipes that outlet onto wide flat
areas with no defined channel are assumed to have a minimum tailwater condition unless
reliable flood stage elevations show otherwise.
Rational Method for Flow
Total Drainage Area(Acres): 30.9
Outlet pipe diameter,Do(in.) 30
Tailwater depth(Feet) 0.5
Tailwater Method To Be Used Min TW(Fig.8.06a)
Discharge(cfs) 28.0
Velocity(ft./s) 4.5
Step 2. Based on the tailwater conditions determined in Step 1, enter Figure 8.06a or Figure 8.06b
and determine the d50 rip rap size and minimum apron length(La). The d50 size is the median
stone size in a well-graded rip rap apron.
Step 3. Determine the apron width at the pipe outlet,the apron shape, and the apron width at the
outlet end from the same figure used in Step 2.
Minimum TW Maximum TW
Riprap d50, (ft.) 0.5
Minimum apron length, La(ft.) ** 16
Apron width at pipe outlet(ft.) 8
Apron shape W=Do+La
Apron width at outlet end(ft.) 19
**-Minimum Apron Length Is 10 Feet per CLDS 20.23
Step 4. Determine the maximum Stone Diameter. D.= 1.5 X d50
Determine the Apron Thickness,Ta= 1.5 X d,nax
Minimum TW Maximum TW
Max Stone Diameter, dmax(Inches): 9 71=
Apron Thickness (Inches): 14
**-Minimum Apron Thickness Is 10 Inches per CLDS 20.23
Step 5. Fit the rip rap apron to the site by making it level for the minimum length La. Extend the
apron farther downstream and along the channel banks until stability is assured. Keep apron
as straight as possible and align it with the flow of the receiving stream. Make any necessary
alignment bends near the pipe outlet so that the entrance into the receiving stream is straight.
Some locations may require lining of the entire channel cross section to assure stability. It
may be necessary to increase the size of the rip rap where protection of the channel side
slopes is necessary. Where overfalls exist at pipe outlets or flows are excessive, a plunge pool
should be considered.

Figure 8.06a: Design of outlet protection from a round pipe flowing full, minimum
tailwater condition (Tw<0.5 diameter)
I_
} 1
IOutlet
diameter (Do) •
pipe i r -_� I I ...� •
: :::� 'N�r
_ �J1 ` r' A
• La _� ¶°. NuI
lwater .< 0. 500 gif. .
e • .::
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ro 60
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ans
0
3 5 10 20 50 100 200 500 1000
Discharge (ft3/sec)
Curves may not be extrapolated.
Figure 8.06a Design of outlet protection protection from a round pipe flowing full, minimum tailwater condition (Tw < 0.5 diameter)
Rev. 1: 93 8.063

STORMWATER MANAGEMENT REPORT
CRESSWIND WESLEY CHAPEL - PHASE 05
APPENDIX F
WATER QUALITY
CALCULATIONS
27842.0005
Pl.
THOMAS & HUTTON

Water Quality Calculations
Cresswind-Wesley Chapel(Phase 05)
Project No.27842.0005
WET POND 06
Project/Drainage Area: 30.93 Acres Required Water Quality Volume: I 65,008 I Cubic Feet
Impervious Area: 18.18 Acres (Project Area(Acres)X 43,560 SF X 1"/12=Required Cubic Feet Volume)
58.8%Percent Impervious Runoff Coefficient: Rv=.05+0.9(I)= I 0.58 I
(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: I 0.376ICFS Required Orifice Size:I 4.00 I Drawdown Time(Hours): I 59.47
Water Quality Elevation Orifice Flow Calculation
Elev. Area Storage Q=CdA*sgrt(2gh)
(ft) (sf) (cu.ft) Cd= 0.62 (Sharp Orifice)
NWL 582.50 54,778 0.00 A= 0.087 sf
TOP OF BERM 588.00 76,035 363,211 g= 32.174 ft/s'
Elevation Pond Depth Storage h= 0.98 ft
(ft) (ft) (cu.ft) 7Q= 0.304 cfs
583.48 0.98 65,008
VPP-Vshelf
U,.e- Abottomofshelf
where: 0.w = Average depth In bet
volume of permanent pool(lest')
I Average Depth Calculation v... - Volume over the shell ally(feed)-see below
Ammedee, Area of wet pond el he bottom of the shelf(rear)
Vpp Designed @ Elevation 582.50 172,326 C.t.t ha^o.qn,...„,,,.•.•r.ameb.„,.,,„,•wtdtn,,,,,,,,,,e...a...
Permanent Pool SA Designed @ Elev 582.50 43,743 = Depth of water el.deep side of the shelf es
sure,etpermanenlpool at n,.
Area of wet pond at the bottom of the shelf 51,434 Perlmebr P elf loa a parmanpl pool aurae bamm onn.
Dmax over shelf 0.50 wtaa fn7rot,
tn-••+e„,„m„r- Wtlth s measured
deep aide manhe dry el(e eof the
t)
shelf as mseeur.d et gmlenent pod(feet)
Perimeter of Permanent Pool 1,124
Width of submerged part of shelf 3.00
Volume over the shelf only 843.26 e e , ,,see se ere enrs wae,rad nsm u.;a.ar,fsedl
Average Depth 3.33 -
EalEMEN0EISEMm
SA/DA Method 20% O. 0.69 - 0_40
Drainage Area 30.93 acres , _, ,_ , „
Table value 1.87
Surface Area Required 25,140.82 square feet

Stage Storage Calculations
Cresswind -Wesley Chapel (Phase 05)
Project No. 27842.0005
WET POND 06
FOREBAY VOLUME
CONTOUR CONTOUR DEPTH (FT) INC.VOL. CUM.VOL.AVG.
ELEV AREA(SF) AVG. END END(CU. FT.)
578 5,281 N/A N/A 0
579 6,181 1 5,731 5,731
580 7,146 1 6,664 12,395
581 8,176 1 7,661 20,056
582 9,271 1 8,723 28,779
582.5 10,613 0.5 4,971 33,750
1_ TOTAL FOREBAY VOLUME: 33,750 CU.FT
PERCENTAGE OF PERMANENT POOL VOLUME: 19.59%
PERMANENT POOL VOLUME
CONTOUR CONTOUR DEPTH (FT) INC.VOL. CUM.VOL.AVG.
t ELEV AREA(SF) AVG. END END(CU. FT.)
578 34,228 N/A N/A 0
579 35,969 1 35,098 35,098
580 37,740 1 36,855 71,953
581 39,540 1 38,640 110,594
582 41,369 1 40,455 151,048
582.5 43,743 0.5 21,278 172,326
PERMANENT POOL VOLUME: 172,326 CU.FT
TEMPORARY PONDING ZONE
CONTOUR CONTOUR DEPTH (FT) INC.VOL. CUM.VOL.AVG.
ELEV AREA(SF) AVG. END END(CU. FT.)
582.5 54,778 N/A N/A 0
583 58,180 0.5 28,240 28,240
584 61,638 1 59,909 88,148
585 65,152 1 63,395 151,543
586 68,723 1 66,938 218,481
587 72,351 1 70,537 289,018
588 76,035 1 74,193 363,211
TEMPORARY PONDING ZONE VOLUME: 363,211 CU. FT.

Cresswind Wesley Chapel-Phase 05 Job: J-27842.0005
O� T
z KH Wesley Chapel,LLC Date: 9/5/23
c4 4 Thomas&Hutton Engineering Co. Revised: 5/29/24
Anti-Flotation Design Considerations By: MSK
ANTI-FLOTATION DESIGN CONSIDERATIONS FOR:
Wet Detention Pond 06
CONTROL STUCTURE ELEVATIONS
Top Structure Elevation: 586.50
Bottom Structure Elevation: 577.00
CONTROL STRUCTURE FLOTATION
Buoyant Force
Calculate submerged volume:
Vs= (Acs x Hcs)
Where:
V,= Submerged volume(cf)
Les= Length of control structure(ft) = 6.00 ft
Wes= Width of control structure(ft) = 6.00 ft
Acs= Cross-sectional area of control structure(sf) = 36.00 sf
Lsb= Length of structural base(ft) = 10.00 ft
Wsb= Width of structure base(ft) = 10.00 ft
Tsb= Thickness of structural base(in) = 13.00 in
Asb= Cross-sectional area of extended base(sf) = 100.00 sf
Hes= Height of control structure(ft) = 9.50 ft
Solve equation for Vs:
V,= (AC5 x HeS)+(Asb x Tsb) = 450.33 cf
Calculate buoyant force:
Fb= Vs x Ywater
Where:
Fb=buoyant force(lbf)
Ywater= Specific weight of water = 62.40 lbf/cf
Fb= 28,101 lbf
Z:\27842\27842.0005\Engineering\Calculations and Reports\Storm Water\Antiflotation Calc\27842.0005-Wet Detention Pond 06-Anti-
Flotation Calcs-2024-05-29 Page 1 of 3

Cresswind Wesley Chapel-Phase 05 Job: J-27842.0005
Z KH Wesley Chapel,LLC Date: 9/5/23
2 Thomas&Hutton Engineering Co. Revised: 5/29/24
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Anti-Flotation Design Considerations By: MSK
Downward Force
Calculate Downward Force of Control Structure
Fdos= (Vcs-Vweir-Vorifice)X yconcrete
Where:
WteS= Weight of control structure(lbs)
?concrete= Specific weight of concrete = 150.00 lbf/cf
Aes= Cross-sectional area of control structure(sf) = 36.00 sf
Hes= Height of control structure(ft) = 9.50 ft
Tes= Wall thickness of control structure(ft) = 0.50 ft
Ves= Volume of control structure(cf) = 104.50 cf
Dop= Diameter of SD Outlet Pipe(ft) = 2.50 ft
Aop= Area of SD Outlet Pipe opening(ft) = 4.91 sf
Vop= Volume of weir = 2.45 cf
Wweir= Width of weir(ft) = 3.00 ft
Hweir= Height of weir opening(ft) = 2.50 ft
Aweir= Area of weir opening(ft) = 7.50 sf
Vweir= Volume of weir = 3.75 cf
DlAorifice= Diameter of orifice opening(in) = 4.00 in
Aorifice= Area of orifice opening(sf) = 0.087 sf
Vorifice= Volume of orifice opening(sf) = 0.044 cf
FdCS= 14,738 lbf
Size Anti-Flotation Footing to Resist Bouyant Force
Fd„+Fdft>Fb
Fdft=(Lb X Wb X Db)X?concrete
Where:
FdeS= downward force of control structure(lbf) = 14738 lbf
Fb=buoyant force(lbf) = 28101 lbf
?concrete= Specific weight of concrete = 150.00 lbf/cf
Leb= Length of Extended Base Slab = 10.00 ft
Web= Width of Extended Base Slab = 10.00 ft
Teb= Thickness of Extended Base Slab = 13.00 in
Fdft= downward force of anti-flotation footing(lbf) = 16250 lbf
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Flotation Calcs-2024-05-29 Page 2 of 3

Cresswind Wesley Chapel-Phase 05 Job: J-27842.0005
O�g T
Z KH Wesley Chapel,LLC Date: 9/5/23
2e Thomas&Hutton Engineering Co. Revised: 5/29/24
Anti-Flotation Design Considerations By: MSK
Fd +Fd fr= 30988 lbf>Fb= 28101 lbf
Factor of Safety
Confirm anti-flotation block is sized for minimum factor of safety(FS)of 1.10.
Fs = (Fdcs+Fdft)/Fb
1.10 > 1.10
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Flotation Calcs-2024-05-29 Page 3 of 3