9809_WilsonCDLF_3ErosionPlan_20220705

DocuSign Envelope ID: 965902A3-FOC6-4C20-8257-5D3CO3CO373E
Attachment
Erosion and Sedimentation Control Plan
Site Study and Permit to Construct Application
Westside CAD Landfill — Area 1 and 2
Wilson, North Carolina

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Erosion and Sedimentation Control Plan
Westside CEO Landfill — Area 2
Wilson, North Carolina
Prepared for:
Wilson County Solid Waste Services Department
Wilson, North Carolina
C
July 2020
(Revised June 2022)
Prepared by:
SMITH GARDNER
14 N. Boylan Avenue, Raleigh NC 27603 1 919.828.0577
Pa INTF� ON i00?- RECCL En PAPER
RARTLETr
ENGFNEENINN a SURVEYING. PC
© 2022 Smith C-erdner, Inc.
This document is intended for the sole use of the client for which it was prepared and
for the purpose agreed upon by the client and Smith Coroner, Inc.

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Erosion and Sedimentation Control Plan
Westside CEO Landfill — Area 2
Wilson, North Carolina
Prepared For:
Wilson County Solid Waste Services Department
Wilson, North Carolina
S+G Project No. Wilson-20-1
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Matthew M. Jones, E.I.
Staff Engineer
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W. Michael Brinchek, P.E.
Senior Project Manager
July2020
(Revised June 2022)
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14 N. Boylan Avenue, Raleigh NC 27603 1 919.828.0577

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Westside CAD Landfill — Area 2
Wilson, North Carolina
Erosion and Sedimentation Control Plan
Table of Contents
Paqe
1.0 NARRATIVE...................................................................................................................
1.1 Project Description....................................................................................................
1.2 Site Location...............................................................................................................
1.3 Contact Information...................................................................................................
1.3.1 Engineer.........................................................................................................
1.3.2 Ovrner.............................................................................................................
1.4 Existing Site Conditions.............................................................................................
1.5 Adjacent Areas...........................................................................................................
1.6 Site Soils Information................................................................................................
2.0 DESIGN GUIDELINES AND PROCEDURES...................................................................
3.0 RUNOFF CALCULATIONS.............................................................................................
3.1 Pre -Developed Conditions........................................................................................
3.2 Post -Developed Conditions.......................................................................................
4.0 EROSION AND SEDIMENTATION CONTROL MEASURES- INITIAL .............................
4.1 Sediment Basin..........................................................................................................
4.2 Drainage Channels....................................................................................................
4.3 Culverts......................................................................................................................
4.4 Drop Inlets..................................................................................................................
4.5 Si It Fence....................................................................................................................
4.6 Vegetative Stabilization.............................................................................................
5.0 EROSION AND SEDIMENTATION CONTROL MEASURES- FINAL ...............................
5.1 Side Slope Swale........................................................................................................
5.2 Down Pipes.................................................................................................................
6.0 SCHEDULE FOR IMPLEMENTATION............................................................................
7.0 INSPECTION AND MAINTENANCE...............................................................................
FIGURES
Figure 1
APPENDICES
Appendix A
Appendix B
USGS Map (Wilson Quadrangle)
1
1
1
1
1
2
2
2
2
2
3
3
3
3
4
4
4
5
5
5
5
5
5
6
6
Erosion and Sedimentation Control Calculations
Erosion and Sedimentation Control and Stormwater Permits & Approvals
Wilson County Westside C&D Landfill -Area 2 Erosion and Sedimentation Control Plan
July 2020 (Revised June 2022) Table of Contents Page i

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Wilson County Westside CH Landfill —Area 2
July 2020 (Revised June 2022)
Erosion and Sedimentation Control Plan
Table of Contents Page ii

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1.0 NARRATIVE
1.1 Project Description
Wilson County plans to construct an expansion (Area 2) of their existing construction and
demolition (C&D) landfill at their landfill facility located off of Highway42 East in Wilson,
North Carolina. The construction and operation of the landfill expansion will require the
disturbance of approximately 44.2 acres. This plan discusses both the initial and long
term (final) erosion and sedimentation control measures used on this project.
1.2 Site Location
The attached USGS map (Wilson Quadrangle) shows the approximate location of the site
and the location of stormwater outfalls for this project. Additional information is as
fol I ows:
1.3
Address:
2400 NC42 East
Wilson, NC27893
Coordinates
(Site Entrance):
Latitude: 35.732 degrees
Longitude:-77.865 degrees
River Basin:
Neuse
Receiving Stream(s)
Toisnot Swamp (Other)
(Stream Classification):
Contact Information
1.3.1 En ineer
For questions regarding this erosion and sedimentation control plan, please
contact the following:
Smith Gardner, Inc.
Attn.: W. Michael Brinchek, P.E.
14 N. Boylan Ave.
Raleigh, NC 27603
Phone: [phone]
Fax: [phone]
Email: mikeamithgardnerinc.com.
Wilson County Westside C&D Landfill- Area 2 Erosion and Sedimentation Control Plan
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1.3.2 Owner
The owner of the site and the person to contact should sediment control issues
arise during the land -disturbing activity is as follows:
Wilson County Solid Waste Services
Attn.: Andy Davis, Director
2400 NC Hwy 42 East
Wilson, NC27893
Phone: [phone]
Fax: [phone].
1.4 Existing Site Conditions
The proposed site occupies an open field on the existing solid waste property,
approximately 2,000 feet northwest of the currently active C&D landfill disposal area.
Existing ground surface elevations varyfrom El. 110 (feet) at the northern end of the
project area and El. 92 at the southern edge of the project area.
1.5 Adjacent Areas
The proposed site lies within County -owned property on all sides. Toisnot swamp, lies
just to the south of the proposed site. The site wil I be accessed from Highway 42 East at
the north end of the site.
1.6 Site Soils Information
The native surficial soils at the site fall under the categories of Wagram loamy sand
(WaB) and Tomotley fine sandy loam (Tt) according to the USDA Natural Resources
Conservation Service soil survey (see Appendix A soil survey map (USDA NRCS Soils
Map)). The Wagram soils can be classified as being in hydrologic soil group (HSG) "A",
and the Tomotley soils can be classified as HSG"B". The majority of borrow soils to be
used in site construction can be classified as being in HSG"A' or "B". For purposes of
runoff calculations soils were conservatively classified as HSG"B".
2.0 DESIGN GUIDELINES AND PROCEDURES
The erosion and sediment control design for the landfill was conducted based on guidelines and
procedures as set forth in the following references:
A. HydroCAD Software Solutions, LLC (2006), HydroCAD Stormwater Modeling System
Owner's Manual - Version 8, Chocorua, NH.
B. Malcom, H. Rooney (1989 & 2003 Supplement), Elements of Urban Stormwater Design,
NC State Univ., Raleigh, NC.
Wilson County Westside C&D Landfill- Area 2 Erosion and Sedimentation Control Plan
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C. North Carolina Division of Land Resources (2013 Update), North Carolina Erosion &
Sediment Control Planning & Design Manual, Raleigh, NC.
3.0 RUNOFF CALCULATIONS
All stormwater flow volumes were calculated using the HydroCAD computer program (utilizing
USDA-NRCS (SCS) methods) based on a 25-year 24-hour design storm event. This storm event,
which is a requirement of current North Carolina solid waste regulations, exceeds the 10-year
24-hour design storm event required by current North Carolina Sediment Control regulations.
Rainfall quantities and/or intensities used in the analyses were derived from an analysis of
design storms for the site. Drainage areas were determined using a planimeter and/or
AutoCAD on topographic sheets of the project area. For each drainage area, runoff curve
numbers (SCS methods) were selected based on ground cover conditions. Times of
concentration were calculated by HydroCAD using SCS methods.
The peak discharge from the 25-year 24-hour storm design storm event was evaluated for both
pre -developed and post developed conditions as described below. The goal of the post -
developed conditions was to limit the peak discharge to no more than pre -developed conditions.
3.1 Pre -Developed Conditions
Pre -developed conditions were modeled in HydroCAD. The total site discharge for pre -
developed conditions was determined to be approximately 21 cfs.
3.2 Post-Develooed Conditions
Post -developed conditions were modeled in HydroCAD. The total site discharge for pre -
developed conditions was determined to be 9 cfs and is, thus, below the peak discharge
for pre -developed conditions.
4.0 EROSION AND SEDIMENTATION CONTROL MEASURES - INITIAL
The following erosion and sedimentation control measures are to be constructed as part of the
proposed construction. Appendices Ato this plan include calculations for each of these
measures. Plans and details for sedimentation control measures area included in the
Engineering Drawings.
In most cases, the following erosion and sedimentation control measures were designed using
the final drainage areas which were found to represent a worst case for design. Each
calculation indicates what condition was used in the analysis.
Wilson County Westside Chi) Landfill -Area 2 Erosion and Sedimentation Control Plan
July 2020 (Revised June 2022) Page 3

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4.1 Sediment Basin
There is one permanent (Sediment Basins 1) sediment basin which will serve the site.
Sediment Basin 1 is to be located on the southern side of the project area. This basin
was designed in accordance with E&SCP&DM Section 6.61.
Sediment basins are subject to several design requirements. Each sediment basin must
have a basin volume of 1,800 ft3/acre of disturbed area and should have a surface area
(measured at crest of principal spillway (riser)) of 0.01 acres/cfs (based on the peak flow
from the 10-year storm). Each basin must include a riser/barrel principal spillway and
must have an emergency spillway (preferably a weir type spillway). The crest of the
emergency spillway is set one foot above the invert of the riser and the spillway must
pass the peak runoff from the design storm event with one foot (min.) of freeboard to
the crest of berm. Each riser/barrel assembly must be provided with an anchor
displacing a buoyant weight of at least 1.1 times the weight of water displaced by the
riser. Each riser must also be provided with a method of dewatering the basin. In
addition to E&SCP&DM requirements, each sediment basin was designed to have an
adequate surface area to achieve an 80% settling efficiency of a 40 micron (silt size)
particle at the peak discharge from the design storm. Each sediment basin was
modeled with the HydroCAD computer program and a spreadsheet was used to verify
the design requirements.
4.2 Drainage Channels
Drainage channel calculations were conducted using a reformulation of Manning's
Equation in a spreadsheet format. The calculations determine the normal depth of flow
based on the peak discharge from the design storm (from HydroCAD) and assumed
channel dimensions/slope(s). Both temporary and/or permanent channel linings were
chosen, as appropriate, based on the calculated velocity and/or shear stress. Steeper
rip rap lined channels (if specified) were analyzed as rock chutes in accordance with
NRCS procedures. Temporary channel linings (if specified) were designed based on the
peak discharge from a 2-year 24-hour design storm.
4.3 Culverts
There are several culverts which will be used at the site to convey flow beneath
roadways and embankments. Culverts were designed either using HydroCAD or a
spreadsheet based on an analysis of inlet and outlet control under the influence of the
design storm to determine the maximum headwater elevation. Where required, culvert
outlets were designed for outlet stabilization based on criteria set forth in E&SCP&DM,
Section 6.41. Culverts draining disturbed areas, which are not routed to a sediment
basin, were designed with a stone filter berm placed around the inlet to trap sediment.
Wilson County Westside CH Landfill -Area 2 Erosion and Sedimentation Control Plan
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4.4 Drop Inlets
Weir -type drop inlets will be used in the perimeter drainage channel. These drop inlets
were designed either using HydroCAD or a spreadsheet based on an analysis of the flow
capacity of the open sides (weirs) of the drop inlet compared to the maximum flow from
the design storm. Prior to vegetative stabilization of the perimeter channel, each drop
inlet wil I be protected from sedimentation by a placing a wire mesh and coarse
aggregate filter around all sides of the drop inlet.
4.5 Silt Fence
Silt fencing design was based on criteria set forth in E&SCP&DM, Section 6.62 including
the limitation of 100 feet of fencing for each'/4 acre of drainage area.
4.6 Vegetative Stabilization
Vegetative stabilization wil I be in accordance with the seeding schedule on the project
drawings and/or in the project specifications.
5.0 EROSION AND SEDIMENTATION CONTROL MEASURES - FINAL
The following erosion and sedimentation control measures are to be constructed as part of final
cover construction. Appendices A, B, and Cto this plan include calculations, technical
specifications, and plans and details (project drawings) for each of these measures,
respectively.
5.1 Side Slooe Swale
A side slope swale wil I be placed near the slope break of the final cover where the 4H:1V
side slopes break to a flatter grade. Flow from the side slope swale is directed to the
down pipes. The capacity and need for lining the side slope swale was checked using the
same procedures as described above for drainage channels.
5.2 Down Pipes
Down pipes wil I be used to carry flows from side slope swales to the bottom of final
cover slopes. Down pipes were designed based on an analysis of inlet and outlet control
under the influence of the design storm to determine the governing headwater condition.
Down pipes will be adequately anchored to the landfill side slopes by use of a soil cover
and each will be outleted directly to perimeter channels (with rip rap outlet protection).
Wilson County Westside CH Landfill -Area 2 Erosion and Sedimentation Control Plan
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6.0 SCHEDULE FOR IMPLEMENTATION
Erosion and sedimentation control measures will be established prior to, or as soon as practical
thereafter, any land disturbance or construction activities may begin in that portion of the site
which drains to the erosion control measures. The following general schedule wil I be followed
for this project:
A. Flag the clearing limits and identify any tree protection areas.
B. Install temporary gravel construction entrance/exit.
C. Clear the vegetated portion of the site and install silt and stone filter fencing prior to
stripping/grubbing.
D. Only strip/grub areas required for installation of structures, berms, and drainage
channels. Other areas wil I be stripped/grubbed once the sediment basin is completed.
E. Install sediment basin outlet structure; outlet protection and/or channel, berm, and
emergency spil Iway.
F. Perform earthwork as required for construction.
G. Perform fine grading and establish permanent vegetation on completed areas.
H. After stabilization, remove silt and stone filter fencing and other temporary measures
and install permanent vegetation on the disturbed areas.
Soil stabilization will be achieved on any area of the site where land disturbing activities have
temporarily or permanently ceased according to the following schedule:
A. All perimeter dikes, swales, ditches, perimeter slopes, and all slopes steeper than 3
horizontal to 1 vertical (31-1:1\� will be provided temporary or permanent stabilization
with ground cover as soon as practicable but in any event within 7 calendar days from
the last land disturbing activity.
B. All other disturbed areas will be provided temporary or permanent stabilization with
ground cover as soon as practicable but in any event within 14 calendar days from the
last land disturbing activity.
C. Basins, traps, channels, and diversions will be lined with anchored rolled erosion control
products or rip rap and/or vegetated upon construction.
D. Permanent ground cover for all disturbed areas will be established within 15 working
days or 90 calendar days (whichever is shorter) following completion of construction or
development.
7.0 INSPECTION AND MAINTENANCE
All erosion and sedimentation control measures will be inspected at least once every 7 calendar
days and within 24 hours after any storm event of greater than 0.5 inches of rain per 24 hour
period and appropriate maintenance conducted. A rain gauge wil I be maintained on the site and
a record of the rainfall amounts and dates wil I be kept.
During inspections, any stormwater discharges from the site wil I be observed for stormwater
discharge characteristics to evaluate the effectiveness of the erosion and sedimentation control
Wilson County Westside CH Landfill- Area 2 Erosion and Sedimentation Control Plan
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measures incorporating Best Management Practices (BMPs). If visible sedimentation is leaving
the disturbed limits of the site, corrective action will be taken immediatelyto control the
discharge of sediments.
Maintenance activities will include, but not be limited to the following:
A. The removal and satisfactory disposal of trapped or deposited sediments from basins,
traps, barriers, filters, and/or drainage features/devices;
B. Replacement of filter fabrics used for silt fences upon loss of efficiency; and
C. Replacement of any other components which are damage or cannot serve the intended
use.
Wilson County Westside CH Landfill -Area 2 Erosion and Sedimentation Control Plan
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Wilson County Westside CH Landfill —Area 2
July 2020 (Revised June 2022)
Erosion and Sedimentation Control Plan
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TITLED "WILSON" AND "SARATOGA", DATED 2019.
PREPARED BY: NO LIC. N0. F-1370 [ENGINEERING]
SC COA NO. C01488
SITE LOCATION MAP SMITH GARDNER
14 N. Boylan Avenue, Raleigh NC 27603 1919.828.0577
1526 Richland St., Columbia SC 29201
DRAWN: APPROVED: SCALE: DATE: PROJECT NO.: FIGURE NO.: FILE NAME:
R.V.M. S.W.H. AS SHOWN Jul 2020 WILSON 20-1 1 WILSON-AO016
© 2020 Smith Gardner, Inc.

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Appendix A
Erosion and Sedimentation Control
Calculations
Erosion and Sedimentation Control Plan
Westside CAD Landfill — Area 2
Wilson, North Carolina

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Erosion and Sedimentation Control Plan
Appendix A: Erosion and Sedimentation Control Calculations
Table of Contents
1.0 Drainage and E&S Control Calculations - Overview
2.0 Analysis of Design Storms
3.0 Drainage Area Figure
4.0 USDA Soil Survey Map
5.0 Stormwater Routing (HydroCAD output)*
• 25-Year 24-Hour Storm
• 100-Year 24-Hour Storm
6.0 Drainage Channel Analysis
7.0 Down Pipe Analysis
8.0 Sedimentation Basin Analysis
9.0 Outlet Protection Analysis
*The design of culverts is included in the HydroCAD output.
Wilson County Westside CH Landfill- Area 2 Erosion and Sedimentation Control Plan
July 2020 (Revised October 2021) Appendix A: Table of Contents Page Al

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July 2020 (Revised October 2021) Appendix A: Table of Contents Page A2

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ADDRESS
TEL I WEB
14 N. Bovlan Avenue, Raleigh, NC27603 1 919.828.0577 1 www.smithgardnerinc.com
PROJECT Westside C&D Landfill -Area 2 SHEET 1 OF 2
SUBJECT Drainage & E&SC Cal Gs. -Overview
JOB # WILSON-20-1
DATE 6/17/2020
COMPUTED BY SWH
CHECKED BY WMB
OBJECTIVE: To design stormwater conveyance, detention, and erosion and sedimentation control measures to remove
and contain stormwater flow from the design storm. The design of these measures will be based on:
Design storm information for the site;
Peak discharge calculations using the Rational Method and/or USDA-NRCS (SCS) Methods; and
Stormwater routing using USDA- NRCS (SCS) or other methods.
REFERENCES: Debo, T.N., and Reese, A.J. (1995), Municipal Storm Water Management, Lewis Publishers, Boca Raton,
FL.
Federal Highway Administration (2001), Urban Drainage Design Manual, Hydraulic Engineering Circular
No. 22, FHWA NHI-01-021, Second Ed., U.S. Dept. of Transportation, Washington, D.C.
Georgia Soil and Water Conservation Commission (2000), Manual for Erosion and Sediment Control in
Georgia, Fifth Edition, Athens, GA.
HydroCAD Software Solutions, LLC(2006), HydroCAD Stormwater Modeling System Owner's Manual -
Version 8, Chocorua, NH.
Malcom, H. Rooney (1989 & 2003 Supplement), Elements of Urban Stormwater Design, NC State Univ.,
Raleigh, NC.
North Carolina Division of Land Resources (2013 Updates), North Carolina Erosion & Sediment Control
Planning & Design Manual, Raleigh, NC.
North Carolina Division of Water Quality (July2005) Updated Draft Manual of Stormwater Best
Management Practices, (Public Comment Version), Raleigh, NC.
Pennsylvania DEP Bureau of Watershed Protection (2000), Erosion and Sediment Pollution Control
Program Manual.
USDA-NRCS (1992), Computer Program for Project Formulation Hydrology(TR-20).
USDA-NRCS (1986 & 1999 Update), Urban Hydrologyfor Small Watersheds (TR-55).
Virginia Department of Conservation and Recreation (1992), Virginia Erosion & Sediment Control
Handbook, Third Edition, Richmond, VA.
ANALYSIS: The main design criteria will be to ensure that all stormwater conveyance and detention measures will be
able to accommodate the runoff from the design storm. Drainage channels, culverts, etc. were designed
based on the peak discharge to each measure. Detention measures were designed based on stormwater
routing methods and/or State/local criteria.
CALCULATIONS:
- Peak Discharge Calculations:
USDA-NRCS(SCS) Methods:
Use HydroCAD program to determine the peak discharge to each device or structure. HydroCAD is based
on the SCS unit hydrograph procedure, which is a principal component of NRCS TR-20. Alternatively
spreadsheets can be used to determine flow rates using the procedures detailed in NRCSTR-55.
SMITH GARDNER,INC. D&E&SCOVERMEWSG

DocuSign Envelope ID: F45A7F90-6A55-4F1A-89A4-806E1A91C808
PROJECT Westside C&D Landfill -Area 2 SHEET 2 OF 2 DATE 6/17/2020
COMPUTED BY SWH
SUBJECT Drainage & E&SC Cal Gs. -Overview JOB # WILSON-20-1 CHECKED BY WMB
Rational Method:
Q= CIA
(Malcom Eq. I -1)
where: C = peak discharge (cfs)
C = rational runoff coefficient
i = applicable rainfall intensity (in/hr) of storm event (based on time of concentration)
A = drainage area (acres)
Time of Concentration:
The time of concentration for use in determining the peak discharge in the NRCS and/or Rational methods
can be determined by the methods detailed in NRCSTR-55 or other methods. HydroCAD uses the NRCS
methods.
- Stormwater Routing:
Stormwater routing was accomplished using the HydroCAD program, which is based on USDA-NRCS (SCS) methods.
Unless otherwise specified, the unit hydrograph method was used. The storm type (i.e. Type 124-hr., Type II 24-hr.,
etc.) was selected as appropriate for the project location.
�11rIll�t<N1�1�i1I
�.11i11111t�L' Ill lJ►i
SMITH GARDNER,INC. D&E&SCOVERMEWSG

DocuSign Envelope ID: F45A7F90-6A55-4F1A-89A4-806E1A91C808
ADDRESS TEL WEB
14 N. Bovlan Avenue, Raleiqh, NC27603 919.828.0577 www.smithgardnerinc.com
PROJECT Westside C&D Landfill -Area 2 SHEET 1 OF 2 DATE 6/17/2020
COMPUTED BY SWH
SUBJECT Analysis of Design Storms JOB # WILSON-20-1 CHECKED BY WMB
OBJECTIVE: To compile the expected design storm depths and intensities over various return periods. These design
storm values will be used in various calculations.
REFERENCES: Rainfall data was obtained from the followinq references:
Frederick, R.H., V.A. Myers, and E.P. Anciel Io (1977), "Five to 60-Minute Precipitation Frequency for the
Eastern and Central United States," NOAATechnical Memo. NWSITYDRO-35, National Weather Service,
NOAA, U.S. Dept. Of Commerce, Silver Spring, MD.
U.S. Weather Bureau (1961), "Rainfall Frequency Atlas of the United States for Durations from 30 Minutes
to 24 Hours and Return Periods from 1 to 100 Years," U.S. Weather Bureau Technical Paper 40.
SMITH GARDNER, INC. DESIGN STORMS SG

DocuSign Envelope ID: F45A7F90-6A55-4F1A-89A4-806E1A91C808
PROJECT Westside C&D Landfill -Area 2
SHEET
2/2
JOB #
WILSCN-20-1
SUBJECT Analysis of Design Storms
DATE
6/17/2020
COMPUTED BY
SWH
CHECKED BY
WMB
LOCATION: Wilson, NC
RETURN PERIOD
2-YR P
100-YR P
SOURCE
DURATION
(in)
(in)
5min
0.48
0.83
NOAAHYDRO-35
15 min
0.97
1.67
NOAAHYDRO-35
60 min
1.69
3.52
NOAAHYDRO-35
2 hr to 24 hr Rainfall Events =
USER INPUT
USWB TP-40
DEPTH -DURATION -FREQUENCY TABLE:
RETURN PERIOD
2-YR
5-YR
10-YR
25-YR
50-YR
100-YR
DURATION
(in)
(in)
(in)
(in)
(in)
(in)
5min
0.48
0.56
0.61
0.70
0.76
0.83
10 m i n
0.77
0.89
0.98
1.11
1.22
1.33
15 m i n
0.97
1.12
1.23
1.40
1.54
1.67
30 min
1.32
1.61
1.81
2.11
2.34
2.58
60 min
1.69
2.12
2.42
2.85
3.19
3.52
2 hr
1.97
2.42
2.90
3.49
4.04
4.60
3 hr
2.09
2.58
3.11
3.79
4.43
5.10
6 hr
2.49
3.08
3.72
4.55
5.33
6.16
12 hr
2.92
3.62
4.39
5.41
6.40
7.43
24 hr
3.51
4.54
5.43
6.79
7.99
9.34
1 INTENSITY- DURATION- FREQUENCY TABLE:
RETURN PERIOD
2-YR
5-YR
10-YR
25-YR
50-YR
100-YR
DURATION
(in/hr)
(in/hr)
(in/hr)
(in/hr)
(in/hr)
(in/hr)
5 min
5.81
6.69
7.36
8.37
9.17
9.97
10 m i n
4.63
5.33
5.87
6.68
7.32
7.96
15 m i n
3.89
4.48
4.93
5.61
6.15
6.68
30 min
2.65
3.22
3.63
4.22
4.69
5.15
60 min
1.69
2.12
2.42
2.85
3.19
3.52
2 hr
0.99
1.21
1.45
1.75
2.02
2.30
3 hr
0.70
0.86
1.04
1.26
1.48
1.70
6 hr
0.42
0.51
0.62
0.76
0.89
1.03
12 hr
0.24
0.30
0.37
0.45
0.53
0.62
24 hr
0.15
0.19
0.23
0.28
0.33
0.39
SMITH GARDNER, INC. DESIGN STORMS SG

DocuSign Envelope ID: F45A7F90-6A55-4F1A-89A4-806E1A91C808
4 7Rboo0 � \
/ C_
■
'00
l\/50' UNDISTU BM WETLA D i l ii i 1
�& STREAM BUFFER I I JI III
IIII
I
LEGEND
EXISTING 10' CONTOUR
(SEE REFERENCE 1)
EXISTING 2' CONTOUR
(SEE REFERENCE 1)
110 PROPOSED 10' CONTOUR
PROPOSED 2' CONTOUR
APPROXIMATE PROPERTY LINE
(SEE REFERENCES 1)
APPROXIMA TE STREAM CENTER LINE
(SEE REFERENCE 2)
5OFT WETLAND AND STREAM BUFFER
20OFT WETLAND AND STREAM BUFFER
TACK ON DIVERSION BERM
DOWN PIPE
C-1
CULVERT
DI-1 ❑
DROP INLET
DC-1
DRAINAGE CHANNEL
FLOOD HAZARD ZONE (0.2PCT ANNUAL
CHANCE) (SEE REFERENCE 3)
FLOOD HAZARD ZONE AE
(SEE REFERENCE 3)
OF P07EN77AL LOGICAL SIGNIFICANCE
R\—M
(TOEA
BE RESERVED) (SEE REFERENCE 6)
FLOOD WA Y
(SEE REFERENCE 3)
WETLANDS
(SEE REFERENCE 4)
BORROW AREA
LIMITS OF GEOMEMBRANE
O GV-13 LANDFILL GAS VENT
*GP-6
PROPOSED LANDFILL GAS MONITORING PROBE
GMW-1
EXISTING C&D LANDFILL AREA 1 GROUNDWA TER
MONITORING WELL (SEE REFERENCE 5)
EXISTING PIEZOME7ER
• P-108
(SEE REFERENCE 5)
EXISTING MONITORING WELL
9 MW-1 A
(SEE REFERENCE 5)
NOTES
1. DRAINAGE CHANNEL INDICATOR REPRESENTS THE START (UPSTREAM) OF
THE CHANNEL CROSS—SECTION.
REFERENCES
1. PARCEL BOUNDARIES, WETLAND AND STREAM LOCATIONS PROVIDED BY
BARTLETT ENGINEERING & SURVEYING, PC. BASED ON FIELD SURVEY DATED
AUGUST 5, 2020.
2. EXISTING TOPOGRAPHY IN ACTIVE AREAS PROVIDED BY BARTLETT ENGINEERING
& SURVEYING, PC. BASED ON FIELD SURVEY DATED AUGUST 5, 2020.
SUPPLEMENTAL TOPOGRAPHY FOR AREAS OUTSIDE OF ACTIVE AREAS PROVIDED
BY FLOOD RISK INFORMATION SYSTEM (FRIS) LiDAR. FEMA MAP NUMBERS
3720373100J AND 3720373200J, DATED 04/16/13.
3. FLOOD HAZARD INFORMATION FROM NORTH CAROLINA FLOODPLAIN MAPPING
PROGRAM, FEMA FIRM MAP NO. 3720373100J, 3772037200J, AND 3720374100J.
4. WETLAND SURVEY AND STREAM DELINEATION DATED MARCH 2O20 FROM SOIL &
ENVIRONMENTAL CONSULTANTS, PA.
5. WELL AND BORING LOCATION PROVIDED BY BARTLETT ENGINEERING &
SURVEYING, PC. BASED ON FIELD SURVEY DATED MAY 27, 2020.
6. ARCHAEOLOGICAL STUDY DATED MAY 2020 FROM ARCHAEOLOGICAL
CONSULTANTS OF THE CAROLINAS, INC.
PERMIT ISSUE
PREPARED FOR:
OF
Kel
PREPARED BY:
VL _IC. NO. F-1370 [ENGINEERING],
SC COA NO. C01488
S M ITH+
GARDNER
:NGINEERS
14 N. Boylan Avenue, Raleigh INC 27603 1 919.828.0577
1526 Richland St., Columbia SC 29201
`EAL
SEAL
REV. DATE DESCRIPTION
10/11/21 RESPONSE TO COMMENTS
DATED 5/3/21
Electronic files are instruments of service provided by Srr tl
Gardner, Inc. for the convenience of the intended recipient; ,, anc
no warranty is ei. ,p- expressed or implied. Any reuse or
redistribution of this document in whole or part without the
written authorization of Smith Gardner, Inc., will be at the sole
risk of the recipient. If there is a discrepancy between the
electronic files and the signed and sealed hard copies, the hard
-opies shall govern. Use of any electronic files generated or
provided by Smith Gardner, Inc., constitutes an acceptance of
these terms and conditions.
PROJECT TITLE:
WILSON COUNTY SOLID WASTE
WESTSIDE CEO LANDFILL
AREA
DRAWING TITLE:
FINAL COVER
GRADING AND
DRAINAGE PLAN
S.W.H. WILSON 20-1
DRAWN: SCALE:
R.V.M. AS SHOWN
APPROVED: DATE:
JULY 2020
FILENAME:
WILSON-DO012
© 2021 Smith Gardner, Inc.
NOT FOR CONSTRUCTION
4 I S3

i
4--d
`-
ro
c
O
4-d
CD
4-a
CD
M

DocuSign Envelope ID: F45A7F90-6A55-4F1A-89A4-806E1A91C808
Custom Soil Resource Report
3 Soil Map
o
240700 240800 240900 241000 241100 241200
35° 4331" N
35° 42' 50" N
240600 240700 240800 240900 241000 241100 241200
3
v
N Map Scale: 1:6,160 if printed on A portrait (8.5" x 11") sheet.
Meters N
0 50 100 200 300
Feet
0 250 500 1000 1500
Map projection: Web Mercator Comer coordinates: WGS84 Edge tics: UTM Zone 18N WGS84
9
N
P,
241300 241400 241500
241300 241400
35° 4331" N
I
r
g
M
8
35° 42' 50" N
241500
3
io
N

DocuSign Envelope ID: F45A7F90-6A55-4F1A-89A4-806E1A91C808
This page intentionally left blank.

DocuSign Envelope ID: F45A7F90-6A55-4F1A-89A4-806E1A91C808
Existing Conditions
OSubca Reach and Lin k

DocuSign Envelope ID: F45A7F90-6A55-4F1A-89A4-806E1A91C808
Westside C&D LF - Existing
Prepared by Smith Gardner, Inc. Page 2
HydroCADO 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC 10/12/2021
Area Listing (all nodes)
Area (acres) CN Description (subcats)
23.610 61 >75% Grass cover, Good, HSG B (1 S)
23.610

DocuSign Envelope ID: F45A7F90-6A55-4F1A-89A4-806E1A91C808
Westside C&D LF - Existing Type 11 24-hr 2 Yr - 24 Hr Rainfall=3.51 "
Prepared by Smith Gardner, Inc. Page 3
HydroCADO 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC 10/12/2021
Time span=5.00-20.00 hrs, dt=0.05 hrs, 301 points
Runoff by SCS TR-20 method, UH=SCS
Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method
Subcatchment 1S: Existing Conditions Runoff Area=23.610 ac Runoff Depth>0.47"
Flow Length=3,500' Slope=0.0100 7' Tc=99.0 min CN=61 Runoff=3.62 cfs 0.923 of
Total Runoff Area = 23.610 ac Runoff Volume = 0.923 of Average Runoff Depth = 0.47"
100.00% Pervious Area = 23.610 ac 0.00% Impervious Area = 0.000 ac

DocuSign Envelope ID: F45A7F90-6A55-4F1A-89A4-806E1A91C808
Westside C&D LF - Existing Type 11 24-hr 2 Yr - 24 Hr Rainfall=3.51 "
Prepared by Smith Gardner, Inc. Page 4
HydroCADO 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC 10/12/2021
Subcatchment 1S: Existing Conditions
Runoff = 3.62 cfs @ 13.34 hrs, Volume= 0.923 af, Depth> 0.47"
Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs
Type II 24-hr 2 Yr - 24 Hr Rainfall=3.51"
Area (ac) CN Description
23.610 61 >75% Grass cover, Good, HSG B
23.610 Pervious Area
Tc Length
Slope
Velocity Capacity
Description
(min) (feet)
(ft/ft)
(ft/sec) (cfs)
18.0 100
0.0100
0.09
Sheet Flow,
Grass: Dense n= 0.240 P2= 3.51"
81.0 3,400
0.0100
0.70
Shallow Concentrated Flow,
Short Grass Pasture Kv= 7.0 fos
99.0 3,500 Total
Subcatchment 1S: Existing Conditions
Hydrograph
❑ Runoff
3.62 cfs
Type 11 24-h r 2 Yr": 24 H r
Rainfa11=3.51 "'
3 Runoff Area=23.610 ac
Runoff Volume=0 923' of
Runoff Depth>0.47'
2 Flow Length=3,500'
U-
Slope : 0.0'100',7
TG=99'.0 min
1 CN=61
viiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiir
5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
Time (hours)

DocuSign Envelope ID: F45A7F90-6A55-4F1A-89A4-806E1A91C808
Westside C&D LF - Existing Type 11 24-hr 25 Yr - 24 Hr Rainfall=6.79"
Prepared by Smith Gardner, Inc. Page 5
HydroCADO 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC 10/12/2021
Time span=5.00-20.00 hrs, dt=0.05 hrs, 301 points
Runoff by SCS TR-20 method, UH=SCS
Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method
Subcatchment 1S: Existing Conditions Runoff Area=23.610 ac Runoff Depth>2.21"
Flow Length=3,500' Slope=0.0100 7' Tc=99.0 min CN=61 Runoff=20.79 cfs 4.356 of
Total Runoff Area = 23.610 ac Runoff Volume = 4.356 of Average Runoff Depth = 2.21"
100.00% Pervious Area = 23.610 ac 0.00% Impervious Area = 0.000 ac

DocuSign Envelope ID: F45A7F90-6A55-4F1A-89A4-806E1A91C808
Westside C&D LF - Existing Type 11 24-hr 25 Yr - 24 Hr Rainfall=6.79"
Prepared by Smith Gardner, Inc. Page 6
HydroCADO 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC 10/12/2021
Subcatchment 1S: Existing Conditions
Runoff = 20.79 cfs @ 13.20 hrs, Volume= 4.356 af, Depth> 2.21"
Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs
Type 11 24-hr 25 Yr - 24 Hr Rainfall=6.79"
Area (ac) CN Description
23.610 61 >75% Grass cover, Good, HSG B
23.610 Pervious Area
Tc Length
Slope
Velocity Capacity
Description
(min) (feet)
(ft/ft)
(ft/sec) (cfs)
18.0 100
0.0100
0.09
Sheet Flow,
Grass: Dense n= 0.240 P2= 3.51"
81.0 3,400
0.0100
0.70
Shallow Concentrated Flow,
Short Grass Pasture Kv= 7.0 fos
99.0 3,500 Total
Subcatchment 1S: Existing Conditions

DocuSign Envelope ID: F45A7F90-6A55-4F1A-89A4-806E1A91C808
Westside C&D LF - Existing Type 11 24-hr 100 Yr- 24 Hr Rainfall= 9.34 "
Prepared by Smith Gardner, Inc. Page 7
HydroCADO 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC 10/12/2021
Time span=5.00-20.00 hrs, dt=0.05 hrs, 301 points
Runoff by SCS TR-20 method, UH=SCS
Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method
Subcatchment 1S: Existing Conditions Runoff Area=23.610 ac Runoff Depth>3.97"
Flow Length=3,500' Slope=0.0100 7' Tc=99.0 min CN=61 Runoff=38.13 cfs 7.808 of
Total Runoff Area = 23.610 ac Runoff Volume = 7.808 of Average Runoff Depth = 3.97"
100.00% Pervious Area = 23.610 ac 0.00% Impervious Area = 0.000 ac

DocuSign Envelope ID: F45A7F90-6A55-4F1A-89A4-806E1A91C808
Westside C&D LF - Existing Type 11 24-hr 100 Yr- 24 Hr Rainfall= 9.34 "
Prepared by Smith Gardner, Inc. Page 8
HydroCADO 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC 10/12/2021
Subcatchment 1S: Existing Conditions
Runoff = 38.13 cfs @ 13.13 hrs, Volume= 7.808 af, Depth> 3.97"
Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs
Type 11 24-hr 100 Yr - 24 Hr Rainfall=9.34"
Area (ac) CN Description
23.610 61 >75% Grass cover, Good, HSG B
23.610 Pervious Area
Tc Length
Slope
Velocity Capacity
Description
(min) (feet)
(ft/ft)
(ft/sec) (cfs)
18.0 100
0.0100
0.09
Sheet Flow,
Grass: Dense n= 0.240 P2= 3.51"
81.0 3,400
0.0100
0.70
Shallow Concentrated Flow,
Short Grass Pasture Kv= 7.0 fos
99.0 3,500 Total
Subcatchment 1S: Existing Conditions

DocuSign Envelope ID: F45A7F90-6A55-4F1A-89A4-806E1A91C808
DC-7 'L DC-1
I
DA-7
DC-6
A9P
DI-1
1S � 10P
Pond Area Basin 1
OSubca Reach and Link
DA-1
DA-2
v
DC-2
DA-3
DA-4
DC-3
DC-4

DocuSign Envelope ID: F45A7F90-6A55-4F1A-89A4-806E1A91C808
Westside C&D LF PTC
Prepared by Smith Gardner, Inc. Page 2
HydroCADO 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC 10/12/2021
Area Listing (all nodes)
Area (acres) CN Description (subcats)
19.839 69 50-75% Grass cover, Fair, HSG B(DA-1,DA-2,DA-3,DA-4,DA-5,DA-6,DA-7)
1.600 85 Gravel roads, HSG B(DA-1,DA-2,DA-3,DA-4,DA-5,DA-6,DA-7)
2.172 98 Paved parking & roofs (1S)
23.611

DocuSign Envelope ID: F45A7F90-6A55-4F1A-89A4-806E1A91C808
Westside C&D LF PTC Type 1124-hr 25 YR - 24 HR Rainfall=6.79"
Prepared by Smith Gardner, Inc. Page 3
HydroCADO 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC 10/12/2021
Time span=5.00-20.00 hrs, dt=0.05 hrs, 301 points
Runoff by SCS TR-20 method, UH=SCS
Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method
Subcatchment 1S: Pond Area Runoff Area=94,600 sf Runoff Depth>5.98"
Tc=5.0 min CN=98 Runoff=21.26 cfs 1.082 of
Subcatchment DA-1: Runoff Area=123,000 sf Runoff Depth>3.17"
Tc=5.0 min CN=70 Runoff=17.48 cfs 0.747 of
Subcatchment DA-2: Runoff Area=100,200 sf Runoff Depth>3.17"
Tc=5.0 min CN=70 Runoff=14.24 cfs 0.608 of
Subcatchment DA-3: Runoff Area=41,400 sf Runoff Depth>3.37"
Tc=5.0 min CN=72 Runoff=6.21 cfs 0.267 of
Subcatchment DA-4: Runoff Area=238,800 sf Runoff Depth>3.17"
Tc=5.0 min CN=70 Runoff=33.94 cfs 1.450 of
Subcatchment DA-5: Runoff Area=65,800 sf Runoff Depth>3.37"
Tc=5.0 min CN=72 Runoff=9.88 cfs 0.425 of
Subcatchment DA-6: Runoff Area=215,300 sf Runoff Depth>3.17"
Tc=5.0 min CN=70 Runoff=30.60 cfs 1.307 of
Subcatchment DA-7: Runoff Area=149,400 sf Runoff Depth>3.17"
Tc=5.0 min CN=70 Runoff=21.23 cfs 0.907 of
Reach DC-1: Avg. Depth=1.40' Max Vet=2.32 fps Inflow=28.45 cfs 1.352 of
n=0.030 L=390.0' S=0.0026 '/' Capacity=139.20 cfs Outflow=26.47 cfs 1.346 of
Reach DC-2: Avg. Depth=0.75' Max Vet=2.86 fps Inflow=14.24 cfs 0.608 of
n=0.030 L=390.0' S=0.0077 '/' Capacity=241.11 cfs Outflow=12.86 cfs 0.606 of
Reach DC-3: Avg. Depth=0.37' Max Vet=3.11 fps Inflow=6.21 cfs 0.267 of
n=0.030 L=400.0' S=0.0200 '/' Capacity=388.78 cfs Outflow=5.65 cfs 0.266 of
Reach DC-4: Avg. Depth=1.23' Max Vet=3.93 fps Inflow=38.59 cfs 1.716 of
n=0.030 L=470.0' S=0.0085 '/' Capacity=253.61 cfs Outflow=35.30 cfs 1.709 of
Reach DC-5: Avg. Depth=1.30' Max Vet=4.56 fps Inflow=47.07 cfs 3.940 of
n=0.030 L=560.0' S=0.0107 '/' Capacity=284.56 cfs Outflow=46.26 cfs 3.926 of
Reach DC-6: Avg. Depth=1.93' Max Vet=2.40 fps Inflow=51.04 cfs 3.545 of
n=0.050 L=750.0' S=0.0053 '/' Capacity=120.46 cfs Outflow=45.61 cfs 3.515 of
Reach DC-7: Avg. Depth=1.75' Max Vet=2.32 fps Inflow=40.75 cfs 2.253 of
n=0.050 L=540.0' S=0.0056 '/' Capacity=122.94 cfs Outflow=36.81 cfs 2.238 of

DocuSign Envelope ID: F45A7F90-6A55-4F1A-89A4-806E1A91C808
Westside C&D LF PTC
Type 11 24-hr 25 YR - 24 HR Rainfall=6.79"
Prepared by Smith Gardner, Inc. Page 4
HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC 10/12/2021
Pond 9P: DI-1
Peak EIev=102.49' Inflow=64.49 cfs 5.635 of
Outflow=64.49 cfs 5.635 of
Pond 10P: Basin 1 Peak EIev=96.28' Storage=182,351 cf Inflow=76.39 cfs 6.717 of
Primary=8.93 cfs 2.792 of Secondary=0.00 cfs 0.000 of Outflow=8.93 cfs 2.792 of
Total Runoff Area = 23.611 ac Runoff Volume = 6.793 of Average Runoff Depth = 3.45"
90.80% Pervious Area = 21.439 ac 9.20% Impervious Area = 2.172 ac

DocuSign Envelope ID: F45A7F90-6A55-4F1A-89A4-806E1A91C808
Westside C&D LF PTC Type 11 24-hr 25 YR - 24 HR Rainfall=6.79"
Prepared by Smith Gardner, Inc. Page 5
HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC 10/12/2021
Subcatchment 1S: Pond Area
[49] Hint: Tc<2dt may require smaller dt
Runoff = 21.26 cfs @ 11.95 hrs, Volume= 1.082 af, Depth> 5.98"
Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs
Type II 24-hr 25 YR - 24 HR Rainfall=6.79"
Area (sf) CN Description
94,600 98 Paved parking & roofs
94,600 Impervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
5.0 Direct Entry,
Subcatchment 1S: Pond Area
Hydrograph
23
❑Runoff
22
21.26 cfs
21
� e IF 4 h
Type 24 HR
I' 25 YR
20
19
17
Runoff sf
15 16
Run-off - �F- olurme .082 of
w 14
13
I
Runoff bepth*5 98-
12
_0 11
Yc 50 min
10
9
GW98
8
7
6
5
4
0
5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
Time (hours)

DocuSign Envelope ID: F45A7F90-6A55-4F1A-89A4-806E1A91C808
Westside C&D LF PTC Type 11 24-hr 25 YR - 24 HR Rainfall=6.79"
Prepared by Smith Gardner, Inc. Page 6
HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC 10/12/2021
Subcatchment DA-1:
[49] Hint: Tc<2dt may require smaller dt
Runoff = 17.48 cfs @ 11.96 hrs, Volume= 0.747 af, Depth> 3.17"
Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs
Type II 24-hr 25 YR - 24 HR Rainfall=6.79"
Area (sf) CN DescriDtion
115,000
69 50-75% Grass cover, Fair, HSG B
8,000
85 Gravel roads, HSG B
123,000
70 Weighted Average
123,000
Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
5.0 Direct Entry,
Subcatchment DA-1:
5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
Time (hours)

DocuSign Envelope ID: F45A7F90-6A55-4F1A-89A4-806E1A91C808
Westside C&D LF PTC Type 11 24-hr 25 YR - 24 HR Rainfall=6.79"
Prepared by Smith Gardner, Inc. Page 7
HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC 10/12/2021
Subcatchment DA-2:
[49] Hint: Tc<2dt may require smaller dt
Runoff = 14.24 cfs @ 11.96 hrs, Volume= 0.608 af, Depth> 3.17"
Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs
Type II 24-hr 25 YR - 24 HR Rainfall=6.79"
Area (sf) CN Description
91,600
69 50-75% Grass cover, Fair, HSG B
8,600
85 Gravel roads, HSG B
100,200
70 Weighted Average
100,200
Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
5.0 Direct Entry,
Subcatchment DA-2:
5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
Time (hours)

DocuSign Envelope ID: F45A7F90-6A55-4F1A-89A4-806E1A91C808
Westside C&D LF PTC Type 11 24-hr 25 YR - 24 HR Rainfall=6.79"
Prepared by Smith Gardner, Inc. Page 8
HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC 10/12/2021
Subcatchment DA-3:
[49] Hint: Tc<2dt may require smaller dt
Runoff = 6.21 cfs @ 11.96 hrs, Volume= 0.267 af, Depth> 3.37"
Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs
Type II 24-hr 25 YR - 24 HR Rainfall=6.79"
Area (sf) CN DescriDtion
34,000 69 50-75% Grass cover, Fair, HSG B
7,400 85 Gravel roads, HSG B
41,400 72 Weighted Average
41,400 Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
5.0 Direct Entry,
Subcatchment DA-3:
Hydrograph
I I ❑Runoff
6.21 cfs
6 Type fl 24 hr 25 YR - 24 HR
Rainfall=6.79"
5 Runoff Area=41,400 sf
Runoff Volume=0.267 of
4 Runoff Depth>3.37"
3
o Tc=5.0 min
LL 3
CN=72
2
1
5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
Time (hours)

DocuSign Envelope ID: F45A7F90-6A55-4F1A-89A4-806E1A91C808
Westside C&D LF PTC Type 11 24-hr 25 YR - 24 HR Rainfall=6.79"
Prepared by Smith Gardner, Inc. Page 9
HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC 10/12/2021
Subcatchment DA-4:
[49] Hint: Tc<2dt may require smaller dt
Runoff = 33.94 cfs @ 11.96 hrs, Volume= 1.450 af, Depth> 3.17"
Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs
Type II 24-hr 25 YR - 24 HR Rainfall=6.79"
Area (sf) CN DescriDtion
229,400
69 50-75% Grass cover, Fair, HSG B
9,400
85 Gravel roads, HSG B
238,800
70 Weighted Average
238,800
Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
5.0 Direct Entry,
Subcatchment DA-4:
Hydrograph
38
■ Runoff
36
3 3.94 cfs
34
TYp'e 1124-hr 25 ',YR 24 HR
30
Rai
nfall=6 79"
28
Runoff Area-238,800 sf
26
24
+
Runoff -Volume-=1.450
of
w 22
Runoff De th>3 1''
R p
20
3 18
Tc=5.0_min
0
u- 16
EN=70
14
12
10
8
6
..
4
5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
Time (hours)

DocuSign Envelope ID: F45A7F90-6A55-4F1A-89A4-806E1A91C808
Westside C&D LF PTC Type 11 24-hr 25 YR - 24 HR Rainfall=6.79"
Prepared by Smith Gardner, Inc. Page 10
HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC 10/12/2021
Subcatchment DA-5:
[49] Hint: Tc<2dt may require smaller dt
Runoff = 9.88 cfs @ 11.96 hrs, Volume= 0.425 af, Depth> 3.37"
Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs
Type II 24-hr 25 YR - 24 HR Rainfall=6.79"
Area (sf) CN DescriDtion
54,100
69 50-75% Grass cover, Fair, HSG B
11,700
85 Gravel roads, HSG B
65,800
72 Weighted Average
65,800
Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
5.0 Direct Entry,
Subcatchment DA-5:
5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
Time (hours)

DocuSign Envelope ID: F45A7F90-6A55-4F1A-89A4-806E1A91C808
Westside C&D LF PTC Type 11 24-hr 25 YR - 24 HR Rainfall=6.79"
Prepared by Smith Gardner, Inc. Page 11
HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC 10/12/2021
Subcatchment DA-6:
[49] Hint: Tc<2dt may require smaller dt
Runoff = 30.60 cfs @ 11.96 hrs, Volume= 1.307 af, Depth> 3.17"
Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs
Type II 24-hr 25 YR - 24 HR Rainfall=6.79"
Area (sf) CN Description
199,600
69 50-75% Grass cover, Fair, HSG B
15,700
85 Gravel roads, HSG B
215,300
70 Weighted Average
215,300
Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
5.0 Direct Entry,
Subcatchment DA-6:
5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
Time (hours)

DocuSign Envelope ID: F45A7F90-6A55-4F1A-89A4-806E1A91C808
Westside C&D LF PTC Type 11 24-hr 25 YR - 24 HR Rainfall=6.79"
Prepared by Smith Gardner, Inc. Page 12
HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC 10/12/2021
Subcatchment DA-7:
[49] Hint: Tc<2dt may require smaller dt
Runoff = 21.23 cfs @ 11.96 hrs, Volume= 0.907 af, Depth> 3.17"
Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs
Type II 24-hr 25 YR - 24 HR Rainfall=6.79"
Area (sf) CN Description
140,500
69 50-75% Grass cover, Fair, HSG B
8,900
85 Gravel roads, HSG B
149,400
70 Weighted Average
149,400
Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
5.0 Direct Entry,
Subcatchment DA-7:
Hydrograph
23 ■Runoff
22 21.23 cfs
- -- ----------- 24-- '------------
21 ' .-
Type--ii-a4-Fir--25--'YR-*- HR----
20 - pp -------------+------------
19 ' ,.. Rat 6 79
------------ nfal, = -.
18-------------------------
Runoff-Area-49,400 O---- 17 `,
15 --------- Run-v 90T --- ------
16 . � �'� - - -- i�LJnCl - - - , � - j -a� -
14
b�ul'1'�e-a.
',-', r � - epth 3---1
13 - U unoff D
12 "
0 11 -.-0- min----
LL CN=70----
10
9 "
8 "
7
6 '.
5
4 -
3
2
1
0
5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
Time (hours)

DocuSign Envelope ID: F45A7F90-6A55-4F1A-89A4-806E1A91C808
Westside C&D LF PTC Type 11 24-hr 25 YR - 24 HR Rainfall=6.79"
Prepared by Smith Gardner, Inc. Page 13
HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC 10/12/2021
Reach DC-1:
[61] Hint: Submerged 46% of Reach DC-2 bottom
Inflow Area = 5.124 ac, Inflow Depth > 3.17" for 25 YR - 24 HR event
Inflow = 28.45 cfs @ 11.98 hrs, Volume= 1.352 of
Outflow = 26.47 cfs @ 12.06 hrs, Volume= 1.346 af, Atten= 7%, Lag= 4.7 min
Routing by Stor-Ind+Trans method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs
Max. Velocity= 2.32 fps, Min. Travel Time= 2.8 min
Avg. Velocity = 0.78 fps, Avg. Travel Time= 8.3 min
Peak Storage= 4,472 cf @ 12.01 hrs, Average Depth at Peak Storage= 1.40'
Bank -Full Depth= 3.00', Capacity at Bank -Full= 139.20 cfs
4.00' x 3.00' deep channel, n= 0.030 Earth, grassed & winding
Side Slope Z-value= 3.0 7' Top Width= 22.00'
Length= 390.0' Slope= 0.0026 7'
Inlet Invert= 115.00', Outlet Invert= 114.00'
❑ Inflow
❑ Outflow
5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
Time (hours)

DocuSign Envelope ID: F45A7F90-6A55-4F1A-89A4-806E1A91C808
Westside C&D LF PTC Type 11 24-hr 25 YR - 24 HR Rainfall=6.79"
Prepared by Smith Gardner, Inc. Page 14
HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC 10/12/2021
Reach DC-2:
Inflow Area = 2.300 ac, Inflow Depth > 3.17" for 25 YR - 24 HR event
Inflow = 14.24 cfs @ 11.96 hrs, Volume= 0.608 of
Outflow = 12.86 cfs @ 12.02 hrs, Volume= 0.606 af, Atten= 10%, Lag= 4.0 min
Routing by Stor-Ind+Trans method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs
Max. Velocity= 2.86 fps, Min. Travel Time= 2.3 min
Avg. Velocity = 0.86 fps, Avg. Travel Time= 7.5 min
Peak Storage= 1,830 cf @ 11.99 hrs, Average Depth at Peak Storage= 0.75'
Bank -Full Depth= 3.00', Capacity at Bank -Full= 241.11 cfs
4.00' x 3.00' deep channel, n= 0.030 Earth, grassed & winding
Side Slope Z-value= 3.0 7' Top Width= 22.00'
Length= 390.0' Slope= 0.0077 '/'
Inlet Invert= 118.00', Outlet Invert= 115.00'
Reach DC-2:
Hydrograph
Inflow
24 cfs ❑ outflow
-nf1OW'-Area 2. 0 -0c-
15 "
12.'
14 "
86 cfs
-.
13 .9. Depth=Q.7S, -
11 -
- --- - ps
Max Vel�2. 6f
12 "
----------- ----------------------- - ----- ----
10
------- ------------' -----------' ' n— O.OaJQQ-0
L=390.0'
3 8 ".. .
— 77
o - --- - ' - - f --
LL7 .
--
-o.00
"
it24--'
'cs5 apacy----- -
4 "
0
5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
Time (hours)

DocuSign Envelope ID: F45A7F90-6A55-4F1A-89A4-806E1A91C808
Westside C&D LF PTC Type 11 24-hr 25 YR - 24 HR Rainfall=6.79"
Prepared by Smith Gardner, Inc. Page 15
HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC 10/12/2021
Reach DC-3:
Inflow Area = 0.950 ac, Inflow Depth > 3.37" for 25 YR - 24 HR event
Inflow = 6.21 cfs @ 11.96 hrs, Volume= 0.267 of
Outflow = 5.65 cfs @ 12.02 hrs, Volume= 0.266 af, Atten= 9%, Lag= 3.6 min
Routing by Stor-Ind+Trans method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs
Max. Velocity= 3.11 fps, Min. Travel Time= 2.1 min
Avg. Velocity = 0.90 fps, Avg. Travel Time= 7.4 min
Peak Storage= 757 cf @ 11.98 hrs, Average Depth at Peak Storage= 0.37'
Bank -Full Depth= 3.00', Capacity at Bank -Full= 388.78 cfs
4.00' x 3.00' deep channel, n= 0.030 Earth, grassed & winding
Side Slope Z-value= 3.0 7' Top Width= 22.00'
Length= 400.0' Slope= 0.0200 7'
Inlet Invert= 117.00', Outlet Invert= 109.00'
6-
5-
4-
3
2
,
1
Reach DC-3:
Hydrograph
6.21 cfs
5.65 cfs
0
5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
Time (hours)
■ Inflow

DocuSign Envelope ID: F45A7F90-6A55-4F1A-89A4-806E1A91C808
Westside C&D LF PTC Type 11 24-hr 25 YR - 24 HR Rainfall=6.79"
Prepared by Smith Gardner, Inc. Page 16
HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC 10/12/2021
Reach DC-4:
Inflow Area = 6.433 ac, Inflow Depth > 3.20" for 25 YR - 24 HR event
Inflow = 38.59 cfs @ 11.96 hrs, Volume= 1.716 of
Outflow = 35.30 cfs @ 12.02 hrs, Volume= 1.709 af, Atten= 9%, Lag= 3.5 min
Routing by Stor-Ind+Trans method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs
Max. Velocity= 3.93 fps, Min. Travel Time= 2.0 min
Avg. Velocity = 1.24 fps, Avg. Travel Time= 6.3 min
Peak Storage= 4,421 cf @ 11.99 hrs, Average Depth at Peak Storage= 1.23'
Bank -Full Depth= 3.00', Capacity at Bank -Full= 253.61 cfs
4.00' x 3.00' deep channel, n= 0.030 Earth, grassed & winding
Side Slope Z-value= 3.07' Top Width= 22.00'
Length= 470.0' Slope= 0.0085 '/'
Inlet Invert= 105.00', Outlet Invert= 101.00'
Reach DC-4:
Hydrograph
- --
-- - --
■ Inflow
42
" ,'"
3 8.59 cfs -- - -
❑ outflow
40
I of how Ada-6.433c
38
36
%" .
3530 cfs
pp
Deh=2V. 3349 '
32
,
_ ' , �
-- -32 S30 -----------
28
26
----------- -------------------_'
42 24
�- 22
-'
-
------------------------- -
L=470.0'
0 20
-
-----------
LL
18
"" .-"
-- -
S=-.0085--''/'
16
------------ r------------'r
14
: '
- ��
- --- Dacity':=- i, 3 6
�I �i.S
12
-
-------
5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
Time (hours)

DocuSign Envelope ID: F45A7F90-6A55-4F1A-89A4-806E1A91C808
Westside C&D LF PTC Type 11 24-hr 25 YR - 24 HR Rainfall=6.79"
Prepared by Smith Gardner, Inc. Page 17
HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC 10/12/2021
Reach DC-5:
[61] Hint: Submerged 32% of Reach DC-6 bottom
Inflow Area = 15.007 ac, Inflow Depth > 3.15" for 25 YR - 24 HR event
Inflow = 47.07 cfs @ 12.17 hrs, Volume= 3.940 of
Outflow = 46.26 cfs @ 12.23 hrs, Volume= 3.926 af, Atten= 2%, Lag= 3.9 min
Routing by Stor-Ind+Trans method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs
Max. Velocity= 4.56 fps, Min. Travel Time= 2.0 min
Avg. Velocity = 1.73 fps, Avg. Travel Time= 5.4 min
Peak Storage= 5,723 cf @ 12.20 hrs, Average Depth at Peak Storage= 1.30'
Bank -Full Depth= 3.00', Capacity at Bank -Full= 284.56 cfs
4.00' x 3.00' deep channel, n= 0.030 Earth, grassed & winding
Side Slope Z-value= 3.0 7' Top Width= 22.00'
Length= 560.0' Slope= 0.0107 '/'
Inlet Invert= 107.00', Outlet Invert= 101.00'
❑ Inflow
❑ Outflow

DocuSign Envelope ID: F45A7F90-6A55-4F1A-89A4-806E1A91C808
Westside C&D LF PTC Type 11 24-hr 25 YR - 24 HR Rainfall=6.79"
Prepared by Smith Gardner, Inc. Page 18
HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC 10/12/2021
Reach DC-6:
[61] Hint: Submerged 64% of Reach DC-7 bottom
Inflow Area = 13.496 ac, Inflow Depth > 3.15" for 25 YR - 24 HR event
Inflow = 51.04 cfs @ 12.00 hrs, Volume= 3.545 of
Outflow = 45.61 cfs @ 12.17 hrs, Volume= 3.515 af, Atten= 11%, Lag= 10.1 min
Routing by Stor-Ind+Trans method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs
Max. Velocity= 2.40 fps, Min. Travel Time= 5.2 min
Avg. Velocity = 0.95 fps, Avg. Travel Time= 13.1 min
Peak Storage= 14,205 cf @ 12.08 hrs, Average Depth at Peak Storage= 1.93'
Bank -Full Depth= 3.00', Capacity at Bank -Full= 120.46 cfs
4.00' x 3.00' deep channel, n= 0.050
Side Slope Z-value= 3.0 7' Top Width= 22.00'
Length= 750.0' Slope= 0.0053 '/'
Inlet Invert= 111.00', Outlet Invert= 107.00'
❑ Inflow
❑ Outflow

DocuSign Envelope ID: F45A7F90-6A55-4F1A-89A4-806E1A91C808
Westside C&D LF PTC Type 11 24-hr 25 YR - 24 HR Rainfall=6.79"
Prepared by Smith Gardner, Inc. Page 19
HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC 10/12/2021
Reach DC-7:
[62] Warning: Submerged 25% of Reach DC-1 inlet
Inflow Area = 8.554 ac, Inflow Depth > 3.16" for 25 YR - 24 HR event
Inflow = 40.75 cfs @ 12.00 hrs, Volume= 2.253 of
Outflow = 36.81 cfs @ 12.11 hrs, Volume= 2.238 af, Atten= 10%, Lag= 6.8 min
Routing by Stor-Ind+Trans method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs
Max. Velocity= 2.32 fps, Min. Travel Time= 3.9 min
Avg. Velocity = 0.84 fps, Avg. Travel Time= 10.7 min
Peak Storage= 8,709 cf @ 12.05 hrs, Average Depth at Peak Storage= 1.75'
Bank -Full Depth= 3.00', Capacity at Bank -Full= 122.94 cfs
4.00' x 3.00' deep channel, n= 0.050
Side Slope Z-value= 3.0 7' Top Width= 22.00'
Length= 540.0' Slope= 0.0056 7'
Inlet Invert= 114.00', Outlet Invert= 111.00'
1
❑ Inflow
❑ Outflow

DocuSign Envelope ID: F45A7F90-6A55-4F1A-89A4-806E1A91C808
Westside C&D LF PTC Type 11 24-hr 25 YR - 24 HR Rainfall=6.79"
Prepared by Smith Gardner, Inc. Page 20
HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC 10/12/2021
Pond 9P: DI-1
[57] Hint: Peaked at 102.49' (Flood elevation advised)
[61] Hint: Submerged 37% of Reach DC-4 bottom
[61] Hint: Submerged 25% of Reach DC-5 bottom
Inflow Area =
21.439 ac,
Inflow Depth > 3.15"
for 25 YR - 24 HR event
Inflow =
64.49 cfs @
12.06 hrs, Volume=
5.635 of
Outflow =
64.49 cfs @
12.06 hrs, Volume=
5.635 af, Atten= 0%, Lag= 0.0 min
Primary =
64.49 cfs @
12.06 hrs, Volume=
5.635 of
Routing by Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs
Peak Elev= 102.49' @ 12.06 hrs
Device Routing Invert Outlet Devices
#1 Primary 93.00' 36.0" x 70.0' long Culvert RCP, square edge headwall, Ke= 0.500
Outlet Invert= 92.00' S= 0.01437' Cc= 0.900
n= 0.011 Concrete pipe, straight & clean
#2 Device 1 101.00' 3.0' long Sharp -Crested Rectangular Weir X 4.00 2 End Contraction(s)
Primary OutFlow Max=63.77 cfs @ 12.06 hrs HW=102.48' (Free Discharge)
L1=Culvert (Passes 63.77 cfs of 96.15 cfs potential flow)
L2=Sharp-Crested Rectangular Weir (Weir Controls 63.77 cfs @ 3.98 fps)
N
V
3
0
LL
Pond 9P: DI-1
Hydrograph
5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
Time (hours)
■ Inflow
❑ Primary

DocuSign Envelope ID: F45A7F90-6A55-4F1A-89A4-806E1A91C808
Westside C&D LF PTC Type 1124-hr 25 YR - 24 HR Rainfall=6.79"
Prepared by Smith Gardner, Inc. Page 21
HydroCADO 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC 10/12/2021
Pond 10P: Basin 1
[82] Warning: Early inflow requires earlier time span
[79] Warning: Submerged Pond 9P Primary device # 1 INLET by 3.28'
Inflow Area =
23.611 ac,
Inflow Depth > 3.41"
for 25 YR - 24 HR event
Inflow =
76.39 cfs @
12.02 hrs,
Volume=
6.717 of
Outflow =
8.93 cfs @
13.20 hrs,
Volume=
2.792 af, Atten= 88%, Lag= 71.0 min
Primary =
8.93 cfs @
13.20 hrs,
Volume=
2.792 of
Secondary =
0.00 cfs @
5.00 hrs,
Volume=
0.000 of
Routing by Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs
Peak Elev= 96.28' @ 13.20 hrs Surf.Area= 52,653 sf Storage= 182,351 cf
Plug -Flow detention time= 211.3 min calculated for 2.792 of (42% of inflow)
Center -of -Mass det. time= 120.9 min ( 911.0 - 790.1 )
Volume Invert Avail.Storage Storage Description
#1 92.00' 279,900 cf Custom Stage Data (Prismatic) Listed below (Recalc)
Elevation Surf.Area Inc.Store Cum.Store
(feet) (sq-ft) (cubic -feet) (cubic -feet)
92.00 32,400 0 0
94.00 42,000 74,400 74,400
96.00 51,300 93,300 167,700
98.00 60,900 112,200 279,900
Device Routing Invert Outlet Devices
#1 Primary 92.00' 18.0" x 60.0' long Culvert RCP, square edge headwall, Ke= 0.500
Outlet Invert= 90.00' S= 0.03337' Cc= 0.900
n= 0.011 Concrete pipe, straight & clean
#2 Device 1 92.10' Special & User -Defined
Head (feet) 0.00 0.10 1.00 10.00
Disch. (cfs) 0.000 1.130 1.130 1.130
#3 Device 1 96.00' 4.0' long Sharp -Crested Rectangular Weir X 4.00 2 End Contraction(s)
#4 Secondary 97.00' 20.0' long x 10.0' breadth Broad -Crested Rectangular Weir
Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60
Coef. (English) 2.49 2.56 2.70 2.69 2.68 2.69 2.67 2.64
Primary OutFlow Max=8.85 cfs @ 13.20 hrs HW=96.28' (Free Discharge)
L1=Culvert (Passes 8.85 cfs of 15.99 cfs potential flow)
t2=Special & User -Defined (Custom Controls 1.13 cfs)
3=Sharp-Crested
Rectangular Weir (Weir Controls 7.72 cfs @ 1.74 fps)
Secondary OutFlow Max=0.00 cfs @ 5.00 hrs HW=92.00' (Free Discharge)
t-4=Broad-Crested Rectangular Weir ( Controls 0.00 cfs)

DocuSign Envelope ID: F45A7F90-6A55-4F1A-89A4-806E1A91C808
Westside C&D LF PTC Type 11 24-hr 25 YR - 24 HR Rainfall=6.79"
Prepared by Smith Gardner, Inc. Page 22
HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC 10/12/2021
Pond 10P: Basin 1
Hydrograph
8.93 cfs
15
10
11 0.00 cfs
5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
Time (hours)

DocuSign Envelope ID: F45A7F90-6A55-4F1A-89A4-806E1A91C808
Westside C&D LF PTC Type 1124-hr 100 YR - 24 HR Rainfall=9.34"
Prepared by Smith Gardner, Inc. Page 23
HydroCADO 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC 10/12/2021
Time span=5.00-20.00 hrs, dt=0.05 hrs, 301 points
Runoff by SCS TR-20 method, UH=SCS
Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method
Subcatchment 1S: Pond Area Runoff Area=94,600 sf Runoff Depth>8.26"
Tc=5.0 min CN=98 Runoff=29.29 cfs 1.495 of
Subcatchment DA-1: Runoff Area=123,000 sf Runoff Depth>5.23"
Tc=5.0 min CN=70 Runoff=28.20 cfs 1.232 of
Subcatchment DA-2: Runoff Area=100,200 sf Runoff Depth>5.23"
Tc=5.0 min CN=70 Runoff=22.97 cfs 1.003 of
Subcatchment DA-3: Runoff Area=41,400 sf Runoff Depth>5.48"
Tc=5.0 min CN=72 Runoff=9.86 cfs 0.434 of
Subcatchment DA-4: Runoff Area=238,800 sf Runoff Depth>5.23"
Tc=5.0 min CN=70 Runoff=54.74 cfs 2.391 of
Subcatchment DA-5: Runoff Area=65,800 sf Runoff Depth>5.48"
Tc=5.0 min CN=72 Runoff=15.67 cfs 0.690 of
Subcatchment DA-6: Runoff Area=215,300 sf Runoff Depth>5.23"
Tc=5.0 min CN=70 Runoff=49.36 cfs 2.156 of
Subcatchment DA-7: Runoff Area=149,400 sf Runoff Depth>5.23"
Tc=5.0 min CN=70 Runoff=34.25 cfs 1.496 of
Reach DC-1: Avg. Depth=1.78' Max Vet=2.66 fps Inflow=46.69 cfs 2.231 of
n=0.030 L=390.0' S=0.0026 '/' Capacity=139.20 cfs Outflow=43.52 cfs 2.222 of
Reach DC-2: Avg. Depth=0.97' Max Vet=3.27 fps Inflow=22.97 cfs 1.003 of
n=0.030 L=390.0' S=0.0077 '/' Capacity=241.11 cfs Outflow=20.93 cfs 1.000 of
Reach DC-3: Avg. Depth=0.48' Max Vet=3.59 fps Inflow=9.86 cfs 0.434 of
n=0.030 L=400.0' S=0.0200 '/' Capacity=388.78 cfs Outflow=9.05 cfs 0.432 of
Reach DC-4: Avg. Depth=1.56' Max Vet=4.47 fps Inflow=62.56 cfs 2.824 of
n=0.030 L=470.0' S=0.0085 '/' Capacity=253.61 cfs Outflow=57.74 cfs 2.815 of
Reach DC-5: Avg. Depth=1.72' Max Vet=5.32 fps Inflow=83.95 cfs 6.505 of
n=0.030 L=560.0' S=0.0107 '/' Capacity=284.56 cfs Outflow=82.57 cfs 6.488 of
Reach DC-6: Avg. Depth=2.54' Max Vet=2.80 fps Inflow=90.06 cfs 5.854 of
n=0.050 L=750.0' S=0.0053 '/' Capacity=120.46 cfs Outflow=81.32 cfs 5.816 of
Reach DC-7: Avg. Depth=2.24' Max Vet=2.66 fps Inflow=68.95 cfs 3.718 of
n=0.050 L=540.0' S=0.0056 '/' Capacity=122.94 cfs Outflow=63.48 cfs 3.699 of

DocuSign Envelope ID: F45A7F90-6A55-4F1A-89A4-806E1A91C808
Westside C&D LF PTC
Type 11 24-hr 100 YR - 24 HR Rainfall=9.34"
Prepared by Smith Gardner, Inc. Page 24
HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC 10/12/2021
Pond 9P: DI-1
Peak EIev=106.02' Inflow=115.54 cfs 9.303 of
Outflow=115.54 cfs 9.303 of
Pond 10P: Basin 1 Peak EIev=97.47' Storage=248,321 cf Inflow=132.27 cfs 10.798 of
Primary=18.49 cfs 6.057 of Secondary=16.90 cfs 0.766 of Outflow=35.38 cfs 6.823 of
Total Runoff Area = 23.611 ac Runoff Volume = 10.896 of Average Runoff Depth = 5.54"
90.80% Pervious Area = 21.439 ac 9.20% Impervious Area = 2.172 ac

DocuSign Envelope ID: F45A7F90-6A55-4F1A-89A4-806E1A91C808
Westside C&D LF PTC Type 11 24-hr 100 YR - 24 HR Rainfall=9.34"
Prepared by Smith Gardner, Inc. Page 25
HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC 10/12/2021
Subcatchment 1S: Pond Area
[49] Hint: Tc<2dt may require smaller dt
Runoff = 29.29 cfs @ 11.95 hrs, Volume= 1.495 af, Depth> 8.26"
Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs
Type II 24-hr 100 YR - 24 HR Rainfall=9.34"
Area (sf) CN Description
94,600 98 Paved parking & roofs
94,600 Impervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
5.0 Direct Entry,
Subcatchment 1S: Pond Area
Hydrograph
32 ❑Runoff
29.29 cfs
30
e tt 24
28 ::Type = 24 HR
-hr,100, YR
nfal
2s
Ra'j 1=9.34"
24 Runoff -Area=94,600 sf -
22 Runoff Volume=1.495 of
20
w 18 Runoff Depth>8 26"
3 16 Tc=5.0 min
LL 14 CN i98
12
10
8
5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
Time (hours)

DocuSign Envelope ID: F45A7F90-6A55-4F1A-89A4-806E1A91C808
Westside C&D LF PTC Type 11 24-hr 100 YR - 24 HR Rainfall=9.34"
Prepared by Smith Gardner, Inc. Page 26
HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC 10/12/2021
Subcatchment DA-1:
[49] Hint: Tc<2dt may require smaller dt
Runoff = 28.20 cfs @ 11.96 hrs, Volume= 1.232 af, Depth> 5.23"
Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs
Type II 24-hr 100 YR - 24 HR Rainfall=9.34"
Area (sf) CN DescriDtion
115,000
69 50-75% Grass cover, Fair, HSG B
8,000
85 Gravel roads, HSG B
123,000
70 Weighted Average
123,000
Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
5.0 Direct Entry,
Subcatchment DA-1:
5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
Time (hours)

DocuSign Envelope ID: F45A7F90-6A55-4F1A-89A4-806E1A91C808
Westside C&D LF PTC Type 11 24-hr 100 YR - 24 HR Rainfall=9.34"
Prepared by Smith Gardner, Inc. Page 27
HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC 10/12/2021
Subcatchment DA-2:
[49] Hint: Tc<2dt may require smaller dt
Runoff = 22.97 cfs @ 11.96 hrs, Volume= 1.003 af, Depth> 5.23"
Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs
Type II 24-hr 100 YR - 24 HR Rainfall=9.34"
Area (sf) CN Description
91,600 69 50-75% Grass cover, Fair, HSG B
8,600 85 Gravel roads, HSG B
100,200 70 Weighted Average
100,200 Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
5.0 Direct Entry,
Subcatchment DA-2:
Hydrograph
5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
Time (hours)

DocuSign Envelope ID: F45A7F90-6A55-4F1A-89A4-806E1A91C808
Westside C&D LF PTC Type 11 24-hr 100 YR - 24 HR Rainfall=9.34"
Prepared by Smith Gardner, Inc. Page 28
HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC 10/12/2021
Subcatchment DA-3:
[49] Hint: Tc<2dt may require smaller dt
Runoff = 9.86 cfs @ 11.95 hrs, Volume= 0.434 af, Depth> 5.48"
Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs
Type II 24-hr 100 YR - 24 HR Rainfall=9.34"
Area (sf) CN DescriDtion
34,000 69 50-75% Grass cover, Fair, HSG B
7,400 85 Gravel roads, HSG B
41,400 72 Weighted Average
41,400 Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
5.0 Direct Entry,
Subcatchment DA-3:
Hydrograph
w
3
0
U-
0
5 6 7 8 9 10
9.86 cf ______ ❑Runoff
s
Type II 24-hr,100'YR
' : 24 HR
Rainfall=9.34"
Runoff Area=41,400 sf
RunoffYolume=0.43A of
Runoff Depth>5.48"
Tc=5.0 min
CN=72
11 12 13 14 15 16 17 18 19 20
Time (hours)

DocuSign Envelope ID: F45A7F90-6A55-4F1A-89A4-806E1A91C808
Westside C&D LF PTC Type 11 24-hr 100 YR - 24 HR Rainfall=9.34"
Prepared by Smith Gardner, Inc. Page 29
HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC 10/12/2021
Subcatchment DA-4:
[49] Hint: Tc<2dt may require smaller dt
Runoff = 54.74 cfs @ 11.96 hrs, Volume= 2.391 af, Depth> 5.23"
Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs
Type II 24-hr 100 YR - 24 HR Rainfall=9.34"
Area (sf) CN DescriDtion
229,400
69 50-75% Grass cover, Fair, HSG B
9,400
85 Gravel roads, HSG B
238,800
70 Weighted Average
238,800
Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
5.0 Direct Entry,
Subcatchment DA-4:
5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
Time (hours)

DocuSign Envelope ID: F45A7F90-6A55-4F1A-89A4-806E1A91C808
Westside C&D LF PTC Type 11 24-hr 100 YR - 24 HR Rainfall=9.34"
Prepared by Smith Gardner, Inc. Page 30
HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC 10/12/2021
Subcatchment DA-5:
[49] Hint: Tc<2dt may require smaller dt
Runoff = 15.67 cfs @ 11.95 hrs, Volume= 0.690 af, Depth> 5.48"
Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs
Type II 24-hr 100 YR - 24 HR Rainfall=9.34"
Area (sf) CN DescriDtion
54,100
69 50-75% Grass cover, Fair, HSG B
11,700
85 Gravel roads, HSG B
65,800
72 Weighted Average
65,800
Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
5.0 Direct Entry,
Subcatchment DA-5:
Hydrograph
17-------------
-
16
------------
15
------------------------------
14
------------
13
-------------
12
-------------
11
------------
w 10
- - - -'- - -� ---
o
I I I
r 9
------------
o g
7
- - - -'----------'-------------' -
6
- - - -'----------'-------------' -
5
-------------
4
- - - -'---------'-----------
3
-------- '-------------------------- '
2
-------------
1
.
5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
Time (hours)

DocuSign Envelope ID: F45A7F90-6A55-4F1A-89A4-806E1A91C808
Westside C&D LF PTC Type 11 24-hr 100 YR - 24 HR Rainfall=9.34"
Prepared by Smith Gardner, Inc. Page 31
HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC 10/12/2021
Subcatchment DA-6:
[49] Hint: Tc<2dt may require smaller dt
Runoff = 49.36 cfs @ 11.96 hrs, Volume= 2.156 af, Depth> 5.23"
Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs
Type II 24-hr 100 YR - 24 HR Rainfall=9.34"
Area (sf) CN Description
199,600
69 50-75% Grass cover, Fair, HSG B
15,700
85 Gravel roads, HSG B
215,300
70 Weighted Average
215,300
Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
5.0 Direct Entry,
Subcatchment DA-6:
Hydrograph
5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
Time (hours)

DocuSign Envelope ID: F45A7F90-6A55-4F1A-89A4-806E1A91C808
Westside C&D LF PTC Type 11 24-hr 100 YR - 24 HR Rainfall=9.34"
Prepared by Smith Gardner, Inc. Page 32
HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC 10/12/2021
Subcatchment DA-7:
[49] Hint: Tc<2dt may require smaller dt
Runoff = 34.25 cfs @ 11.96 hrs, Volume= 1.496 af, Depth> 5.23"
Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs
Type II 24-hr 100 YR - 24 HR Rainfall=9.34"
Area (sf) CN DescriDtion
140,500
69 50-75% Grass cover, Fair, HSG B
8,900
85 Gravel roads, HSG B
149,400
70 Weighted Average
149,400
Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
5.0 Direct Entry,
Subcatchment DA-7:
5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
Time (hours)

DocuSign Envelope ID: F45A7F90-6A55-4F1A-89A4-806E1A91C808
Westside C&D LF PTC Type 11 24-hr 100 YR - 24 HR Rainfall=9.34"
Prepared by Smith Gardner, Inc. Page 33
HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC 10/12/2021
Reach DC-1:
[61] Hint: Submerged 59% of Reach DC-2 bottom
Inflow Area = 5.124 ac, Inflow Depth > 5.23" for 100 YR - 24 HR event
Inflow = 46.69 cfs @ 11.98 hrs, Volume= 2.231 of
Outflow = 43.52 cfs @ 12.05 hrs, Volume= 2.222 af, Atten= 7%, Lag= 4.2 min
Routing by Stor-Ind+Trans method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs
Max. Velocity= 2.66 fps, Min. Travel Time= 2.4 min
Avg. Velocity = 0.86 fps, Avg. Travel Time= 7.6 min
Peak Storage= 6,512 cf @ 12.00 hrs, Average Depth at Peak Storage= 1.78'
Bank -Full Depth= 3.00', Capacity at Bank -Full= 139.20 cfs
4.00' x 3.00' deep channel, n= 0.030 Earth, grassed & winding
Side Slope Z-value= 3.07' Top Width= 22.00'
Length= 390.0' Slope= 0.0026 'i'
Inlet Invert= 115.00', Outlet Invert= 114.00'
❑ Inflow
❑ Outflow
5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
Time (hours)

DocuSign Envelope ID: F45A7F90-6A55-4F1A-89A4-806E1A91C808
Westside C&D LF PTC Type 11 24-hr 100 YR - 24 HR Rainfall=9.34"
Prepared by Smith Gardner, Inc. Page 34
HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC 10/12/2021
Reach DC-2:
Inflow Area = 2.300 ac, Inflow Depth > 5.23" for 100 YR - 24 HR event
Inflow = 22.97 cfs @ 11.96 hrs, Volume= 1.003 of
Outflow = 20.93 cfs @ 12.01 hrs, Volume= 1.000 af, Atten= 9%, Lag= 3.3 min
Routing by Stor-Ind+Trans method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs
Max. Velocity= 3.27 fps, Min. Travel Time= 2.0 min
Avg. Velocity = 0.96 fps, Avg. Travel Time= 6.8 min
Peak Storage= 2,597 cf @ 11.98 hrs, Average Depth at Peak Storage= 0.97'
Bank -Full Depth= 3.00', Capacity at Bank -Full= 241.11 cfs
4.00' x 3.00' deep channel, n= 0.030 Earth, grassed & winding
Side Slope Z-value= 3.0 7' Top Width= 22.00'
Length= 390.0' Slope= 0.0077 '/'
Inlet Invert= 118.00', Outlet Invert= 115.00'
Reach DC-2:
Hydrograph
----- - ■ Inflow
22.97 cf
s ❑ outflow
24 1nf1oW: Area=�2.3p0 ac -
22 , 20.93 cfs ---
'
=0.97'Avg Depth 20 718 'axv@�=32;fps
---
16
n=0.03042 -
L=390.0'
n 14
c 12 -
S= LL
©.007-7--'T
8"
--- Capaaity'�=24 1.'1;1 cfs
6 ------------------------------------ -- ------
5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
Time (hours)

DocuSign Envelope ID: F45A7F90-6A55-4F1A-89A4-806E1A91C808
Westside C&D LF PTC Type 11 24-hr 100 YR - 24 HR Rainfall=9.34"
Prepared by Smith Gardner, Inc. Page 35
HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC 10/12/2021
Reach DC-3:
Inflow Area = 0.950 ac, Inflow Depth > 5.48" for 100 YR - 24 HR event
Inflow = 9.86 cfs @ 11.95 hrs, Volume= 0.434 of
Outflow = 9.05 cfs @ 12.01 hrs, Volume= 0.432 af, Atten= 8%, Lag= 3.1 min
Routing by Stor-Ind+Trans method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs
Max. Velocity= 3.59 fps, Min. Travel Time= 1.9 min
Avg. Velocity = 1.00 fps, Avg. Travel Time= 6.7 min
Peak Storage= 1,045 cf @ 11.98 hrs, Average Depth at Peak Storage= 0.48'
Bank -Full Depth= 3.00', Capacity at Bank -Full= 388.78 cfs
4.00' x 3.00' deep channel, n= 0.030 Earth, grassed & winding
Side Slope Z-value= 3.0 '/' Top Width= 22.00'
Length= 400.0' Slope= 0.0200 '/'
Inlet Invert= 117.00', Outlet Invert= 109.00'
0
Reach DC-3:
Hydrograph
5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
Time (hours)
■ Inflow

DocuSign Envelope ID: F45A7F90-6A55-4F1A-89A4-806E1A91C808
Westside C&D LF PTC Type 11 24-hr 100 YR - 24 HR Rainfall=9.34"
Prepared by Smith Gardner, Inc. Page 36
HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC 10/12/2021
Reach DC-4:
Inflow Area = 6.433 ac, Inflow Depth > 5.27" for 100 YR - 24 HR event
Inflow = 62.56 cfs @ 11.96 hrs, Volume= 2.824 of
Outflow = 57.74 cfs @ 12.01 hrs, Volume= 2.815 af, Atten= 8%, Lag= 3.0 min
Routing by Stor-Ind+Trans method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs
Max. Velocity= 4.47 fps, Min. Travel Time= 1.8 min
Avg. Velocity = 1.38 fps, Avg. Travel Time= 5.7 min
Peak Storage= 6,329 cf @ 11.98 hrs, Average Depth at Peak Storage= 1.56'
Bank -Full Depth= 3.00', Capacity at Bank -Full= 253.61 cfs
4.00' x 3.00' deep channel, n= 0.030 Earth, grassed & winding
Side Slope Z-value= 3.0 7' Top Width= 22.00'
Length= 470.0' Slope= 0.0085 '/'
Inlet Invert= 105.00', Outlet Invert= 101.00'
Reach DC-4:
Hydrograph
70
------ �
■ Inflow
62.56 c fs
❑ outflow
65
----33 -
Inflow: ac
60
-'Depth=l.6'
57.74 cfs ----- ----- - -
-Avg.
55
50
Max ite f-4 7 Jps
45
- —
• ' � -'
30
F 40
35
, '
------------', ----------- 4
— IO 'O
o
-
u. 30
.- "
_
S=0.0085''/'
25
-'
- - - - -
--------- {--- Capacity,=253.61 --- cfs
20
15
-
10
5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
Time (hours)

DocuSign Envelope ID: F45A7F90-6A55-4F1A-89A4-806E1A91C808
Westside C&D LF PTC Type 11 24-hr 100 YR - 24 HR Rainfall=9.34"
Prepared by Smith Gardner, Inc. Page 37
HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC 10/12/2021
Reach DC-5:
[61] Hint: Submerged 43% of Reach DC-6 bottom
Inflow Area = 15.007 ac, Inflow Depth > 5.20" for 100 YR - 24 HR event
Inflow = 83.95 cfs @ 12.13 hrs, Volume= 6.505 of
Outflow = 82.57 cfs @ 12.19 hrs, Volume= 6.488 af, Atten= 2%, Lag= 3.2 min
Routing by Stor-Ind+Trans method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs
Max. Velocity= 5.32 fps, Min. Travel Time= 1.8 min
Avg. Velocity = 1.92 fps, Avg. Travel Time= 4.9 min
Peak Storage= 8,785 cf @ 12.16 hrs, Average Depth at Peak Storage= 1.72'
Bank -Full Depth= 3.00', Capacity at Bank -Full= 284.56 cfs
4.00' x 3.00' deep channel, n= 0.030 Earth, grassed & winding
Side Slope Z-value= 3.07' Top Width= 22.00'
Length= 560.0' Slope= 0.0107 'i'
Inlet Invert= 107.00', Outlet Invert= 101.00'
❑ Inflow
❑ Outflow
I
1
1
.
1,
Time (hours)

DocuSign Envelope ID: F45A7F90-6A55-4F1A-89A4-806E1A91C808
Westside C&D LF PTC Type 11 24-hr 100 YR - 24 HR Rainfall=9.34"
Prepared by Smith Gardner, Inc. Page 38
HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC 10/12/2021
Reach DC-6:
[61] Hint: Submerged 84% of Reach DC-7 bottom
Inflow Area = 13.496 ac, Inflow Depth > 5.21" for 100 YR - 24 HR event
Inflow = 90.06 cfs @ 12.00 hrs, Volume= 5.854 of
Outflow = 81.32 cfs @ 12.14 hrs, Volume= 5.816 af, Atten= 10%, Lag= 8.5 min
Routing by Stor-Ind+Trans method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs
Max. Velocity= 2.80 fps, Min. Travel Time= 4.5 min
Avg. Velocity = 1.05 fps, Avg. Travel Time= 11.9 min
Peak Storage= 22,097 cf @ 12.06 hrs, Average Depth at Peak Storage= 2.54'
Bank -Full Depth= 3.00', Capacity at Bank -Full= 120.46 cfs
4.00' x 3.00' deep channel, n= 0.050
Side Slope Z-value= 3.07' Top Width= 22.00'
Length= 750.0' Slope= 0.0053 'i'
Inlet Invert= 111.00', Outlet Invert= 107.00'
1
3
0
LL
0
5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
Time (hours)

DocuSign Envelope ID: F45A7F90-6A55-4F1A-89A4-806E1A91C808
Westside C&D LF PTC Type 11 24-hr 100 YR - 24 HR Rainfall=9.34"
Prepared by Smith Gardner, Inc. Page 39
HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC 10/12/2021
Reach DC-7:
[62] Warning: Submerged 41 % of Reach DC-1 inlet
Inflow Area = 8.554 ac, Inflow Depth > 5.22" for 100 YR - 24 HR event
Inflow = 68.95 cfs @ 11.99 hrs, Volume= 3.718 of
Outflow = 63.48 cfs @ 12.09 hrs, Volume= 3.699 af, Atten= 8%, Lag= 5.9 min
Routing by Stor-Ind+Trans method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs
Max. Velocity= 2.66 fps, Min. Travel Time= 3.4 min
Avg. Velocity = 0.93 fps, Avg. Travel Time= 9.7 min
Peak Storage= 12,966 cf @ 12.03 hrs, Average Depth at Peak Storage= 2.24'
Bank -Full Depth= 3.00', Capacity at Bank -Full= 122.94 cfs
4.00' x 3.00' deep channel, n= 0.050
Side Slope Z-value= 3.07' Top Width= 22.00'
Length= 540.0' Slope= 0.0056 'i'
Inlet Invert= 114.00', Outlet Invert= 111.00'
�Mi
❑ Inflow
❑ Outflow

DocuSign Envelope ID: F45A7F90-6A55-4F1A-89A4-806E1A91C808
Westside C&D LF PTC Type 11 24-hr 100 YR - 24 HR Rainfall=9.34"
Prepared by Smith Gardner, Inc. Page 40
HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC 10/12/2021
Pond 9P: DI-1
[57] Hint: Peaked at 106.02' (Flood elevation advised)
[62] Warning: Submerged 33% of Reach DC-4 inlet
[61] Hint: Submerged 83% of Reach DC-5 bottom
Inflow Area = 21.439 ac, Inflow Depth > 5.21" for 100 YR - 24 HR event
Inflow = 115.54 cfs @ 12.06 hrs, Volume= 9.303 of
Outflow = 115.54 cfs @ 12.06 hrs, Volume= 9.303 af, Atten= 0%, Lag= 0.0 min
Primary = 115.54 cfs @ 12.06 hrs, Volume= 9.303 of
Routing by Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs
Peak Elev= 106.02' @ 12.06 hrs
Device Routing Invert Outlet Devices
#1 Primary 93.00' 36.0" x 70.0' long Culvert RCP, square edge headwall, Ke= 0.500
Outlet Invert= 92.00' S= 0.01437' Cc= 0.900
n= 0.011 Concrete pipe, straight & clean
#2 Device 1 101.00' 3.0' long Sharp -Crested Rectangular Weir X 4.00 2 End Contraction(s)
Primary OutFlow Max=114.75 cfs @ 12.06 hrs HW=105.87' (Free Discharge)
L1=Culvert (Inlet Controls 114.75 cfs @ 16.23 fps)
L2=Sharp-Crested Rectangular Weir (Passes 114.75 cfs of 284.64 cfs potential flow)
N
V
3
0
LL
Pond 9P: DI-1
Hydrograph
5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
Time (hours)
■ Inflow
❑ Primary

DocuSign Envelope ID: F45A7F90-6A55-4F1A-89A4-806E1A91C808
Westside C&D LF PTC Type 11 24-hr 100 YR - 24 HR Rainfall=9.34"
Prepared by Smith Gardner, Inc. Page 41
HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC 10/12/2021
Pond 10P: Basin 1
[82] Warning:
Early inflow requires earlier time span
[79] Warning:
Submerged Pond
9P Primary device #
1 INLET by 4.47'
Inflow Area =
23.611 ac,
Inflow Depth > 5.49"
for 100 YR - 24 HR event
Inflow =
132.27 cfs @
12.02 hrs, Volume=
10.798 of
Outflow =
35.38 cfs @
12.55 hrs, Volume=
6.823 af, Atten= 73%, Lag= 31.9 min
Primary =
18.49 cfs @
12.55 hrs, Volume=
6.057 of
Secondary =
16.90 cfs @
12.55 hrs, Volume=
0.766 of
Routing by Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs
Peak Elev= 97.47' @ 12.55 hrs Surf.Area= 58,358 sf Storage= 248,321 cf
Plug -Flow detention time= 150.8 min calculated for 6.823 of (63% of inflow)
Center -of -Mass det. time= 78.5 min ( 859.3 - 780.8 )
Volume Invert Avail.Storage Storage Description
#1 92.00' 279,900 cf Custom Stage Data (Prismatic) Listed below (Recalc)
Elevation Surf.Area Inc.Store Cum.Store
(feet) (sq-ft) (cubic -feet) (cubic -feet)
92.00 32,400 0 0
94.00 42,000 74,400 74,400
96.00 51,300 93,300 167,700
98.00 60,900 112,200 279,900
Device Routing Invert Outlet Devices
#1 Primary 92.00' 18.0" x 60.0' long Culvert RCP, square edge headwall, Ke= 0.500
Outlet Invert= 90.00' S= 0.03337' Cc= 0.900
n= 0.011 Concrete pipe, straight & clean
#2 Device 1 92.10' Special & User -Defined
Head (feet) 0.00 0.10 1.00 10.00
Disch. (cfs) 0.000 1.130 1.130 1.130
#3 Device 1 96.00' 4.0' long Sharp -Crested Rectangular Weir X 4.00 2 End Contraction(s)
#4 Secondary 97.00' 20.0' long x 10.0' breadth Broad -Crested Rectangular Weir
Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60
Coef. (English) 2.49 2.56 2.70 2.69 2.68 2.69 2.67 2.64
Primary OutFlow Max=18.49 cfs @ 12.55 hrs HW=97.47' (Free Discharge)
L1=Culvert (Inlet Controls 18.49 cfs @ 10.46 fps)
�__3=Sharp-Crested
2=Special & User -Defined (Passes < 1.13 cfs potential flow)
Rectangular Weir (Passes < 86.42 cfs potential flow)
Secondary OutFlow Max=16.83 cfs @ 12.55 hrs HW=97.47' (Free Discharge)
L4=Broad-Crested Rectangular Weir (Weir Controls 16.83 cfs @ 1.79 fps)

DocuSign Envelope ID: F45A7F90-6A55-4F1A-89A4-806E1A91C808
Westside C&D LF PTC Type 1124-hr 100 YR - 24 HR Rainfall=9.34"
Prepared by Smith Gardner, Inc. Page 42
HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC 10/12/2021
Pond 10P: Basin 1
Hydrograph
132.27 cfs
- - - --, - --- �'�-----+------ --- - �'� -- ---� -- --- �'� - --- -
utflow
ow' Area=23.61-1_-ac- -��f�
IMInflow
rimary
econdary
140
- eak Efev=97- 47
130
-
Storage-248,321 cf-
120
__
110----
---------------
100 ,' :"
- - --- - -'-- --'---------- �'�-----'-----'----- �'�-----'---- --- --- --- ---
90
----- -- --- ----- ----- ----- ----- ----- -----
42
-� 80
0 70
--- -�---------------------------- ----- -� ----- -
60
35.38 cfs
50 ; "
- - - - - -'--------------------'----------- ------------------------------- '-----------
40
30
18.49 cfs
16.90 cfs
20zz
5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
Time (hours)

DocuSign Envelope ID: F45A7F90-6A55-4F1A-89A4-806E1A91C808
TEL I WEB
14 N. Boylan Avenue, Raleigh, NC27603 919.828.0577 1 www.smithgardnerinc.com
PROJECT Westside C&D Landfill -Area 2 SHEET 1 OF 11
SUBJECT Drainage Channel Analysis JOB # WILSON-20-1
DATE 7/17/2020
COMPUTED BY SWH
CHECKED BY WMB
OBJECTIVE: To design drainage channels, ditches, etc. to handle stormwater flow from the design storm(s). The main
design criteria will be to ensure that all drainage channels, ditches, etc. will be able to accommodate the
peak discharge from the design storm without overtopping and without exceeding the allowable shear
stress and/or velocity of the selected channel lining.
REFERENCES: Federal Highway Administration (2001), Urban Drainage Design Manual, Hydraulic Engineering Circular
No. 22, FHWA NHI-01-021, Second Ed., U.S. Dept. of Transportation, Washington, D.C.
North Carolina Division of Land Resources (2013 Updates), North Carolina Erosion & Sediment Control
Planning & Design Manual, Raleigh, NC.
Malcom, H. Rooney (1989 & 2003 Supplement), Elements of Urban Stormwater Design, NC State Univ.,
Raleigh, NC.
Pennsylvania DEP Bureau of Watershed Protection (2000), Erosion and Sediment Pollution Control
Program Manual.
ANALYSIS: The following approach is used in the design of drainage channels:
1 Determine the peak discharge from the design storm(s) (from HydroCAD or spreadsheet
methods). For permanent linings (Grass, TRM, rip rap, gabions, etc.) use the peak discharge
from the 25-Yr 24-Hr storm unless otherwise specified. For grass lined channels, a smaller
design storm (2-Yr 24-Hr -unless otherwise specified) is used to evaluate temporary linings.
2- Input other design parameters (bottom width side slopes minimum freeboard, min./max.
slopes and channel lining).
3. Based on the design parameters calculate normal depth of flow, velocity, Froude number, and
maximum shear stress for both max./min. slopes. Also determine the critical slope and
corresponding normal depth.
4. Compare the velocity and/or shear stress to allowable values (the maximum slope val ues will
control). If val ues are exceeded, revise design parameters as required.
5. Based on normal depth values and required freeboard (generally use the greater of 6 inches or
25 of the flow depth), determine the minimum channel depth and top width for both max./min.
slopes (the minimum slope values will control).
6. If the channel has a significant curved reach, evaluate the shear stress and superelevation of
the water surface in the bend.
CALCULATIONS:
- Manning s Equation:
1.49AR213S112 AV (HEC-22 Eq. 5-5)
Q=
n
where: Q = discharge (cfs)
n = Manning s roughness coefficient (See Below)
A = cross sectional area of flow (ft2)
R = hydraulic radius (ft) = A/P
P = wetted perimeter
S = slope of channel (ft/ft)
V = average channel velocity (ft/sec)
SMITH GARNER, INC. DRAINAGE CHANNEL-Westside C&DArea 2

DocuSign Envelope ID: F45A7F90-6A55-4F1A-89A4-806E1A91C808
PROJECT Westside C&D Landfill -Area 2 SHEET
SUBJECT Drainage Channel Analysis JOB#
2 OF 11
WI LSON-20-1
- Maximum Shear Stress (Tractive Force Method
zd = )dS (HEC-22 Eq. 5-13)
where: r, = maximum shear stress on channel lining (psf)
y = unit weight of water (62.4 pcf)
d = maximum depth of flow (ft)
S = channel slope (ft/ft)
- Froude Number:
DATE 7/17/2020
COMPUTED BY SWH
CHECKED BY WMB
where: F, = Froude number (dimensionless)
v = flow velocity (ft/sec)
g = acceleration of gravity (32.2 ft/sec`)
A = cross -sectional area of flow (W)
T = top width of flow (ft)
Note that A/T=the hydraulic depth (D). For Fr 1.0, flow is supercritical Fr 1.0, flow is subcritical Fr = 1.0, flow is
critical.
Critical Slope:
The critical slope (Sj is the slope at which Fr = 1.0. When the slope is between 0.7S. and 1.3S. , unstable
flow may occur as small flow disturbances can initiate a change in the flow state. If slopes are within this
range, consider additional freeboard.
- Manning s Roughness Coefficient (n):
Grass:
Rip Ram
R v6
(HEC-22 Eq. 5-6 - 5-10)
n =
[K+ 19.971og(R14SO4)]
where: R =
hydraulic radius (ft)
K =
vegetative coefficient (depending on retardance class)
=15.8 (Class A)
= 23.0 (CI ass B)
= 30.2 (a ass C)
= 34.6 (CI ass D)
= 37.7 (Class E)
S =
slope of channel (ft/ft)
y v6
n=
21.61og( Y + 14
d50
where: y =
050 _
depth of flow (ft)
median si e of rip rap (ft)
(PA DEP Manual Fig. 3)
SMITH GARDNER, INC. DRAINAGE CHAN N EL-Westside C&DArea 2

DocuSign Envelope ID: F45A7F90-6A55-4F1A-89A4-806E1A9lC808
PROJECT Westside C&D Landfill -Area 2 SHEET
SUBJECT Drainage Channel Analysis JOB #
- Curved Channels (WhereApplicable.
Shear Stress in Bend:
Zb = Kb Zd
where: r a =
Kb =
ra =
B=
Superelevation at Outside of Bend:
TVZT
A d = 0.5
gR,
3 OF 11
WI LSON-20-1
(HEC-22 Eq. 5-15)
bend shear stress (psf)
function of Rc/B (use HEC-22 Chart 21)
maximum shear stress on channel lining (psf)
radius to the centerline of the channel (ft)
bottom width of channel (ft)
(HEC-22 Eq. 5-11 modified)
DATE 7/17/2020
COMPUTED BY SWH
CHECKED BY WMB
where: A o = superelevation of water surface between the outer channel bank and the
centerline of the channel (avg. water surface before bend) (ft)
V = average channel velocity (ft/sec)
T = top width of flow (ft)
g = acceleration of gravity (32.2 ft/sec2)
A, = radius to the centerline of the channel (ft)
- Allowable Shear Stress/Velocity:
Grass -Lined Channels:
For grass -lined channels, an allowable velocity approach is applicable for slopes flatter than 10 . For
slopes of 10 and steeper appropriate permanent linings should be used. For use in the evaluation of
curved channels, the following allowable shear stress values (lb/ft2) can be assumed based on retardance
cl ass:
Class A: 3.7
Gass B: 2.1
Class C: 1
Gass D: 0.6
CI ass E: 0.35
Rip Rap -Lined Channels:
For rip rap -lined channels, an allowable velocity approach is applicable for slopes flatter than 10% (see table
below). For slopes of 10% or steeper, use the following equation:
Z7,1/,_ = 4 x dso (HEC-22 Eq. 5-17)
where: rallow = allowable shear stress (psf)
aM = median si a of rip rap (ft)
SMITH GARDNER, INC. DRAINAGE CHANNEL-Westside C&DArea 2

DocuSign Envelope ID: F45A7F90-6A55-4F1A-89A4-806E1A91C808
PROJECT Westside CBDLandfil l -Area 2
SHEET
4/15
JOB#
WILSON-20-1
SUBJECT Drainage Channel Analysis (Grass Lined)
DATE
10/11/2021
COMPUTED BY
SWH
Channel No.
DC-1
CHECKEDBY
WMB
Design
Parameters:
PEAK DISCHARGE, Q?=
7.5
ft'/s
Source:
HydroCAD 2-Yr 24-Hr
PEAK DISCHARGE, r225=
28.5
ftl/s
Source:
HydroCAD25-Yr24-Hr
Bottom Width, B =
4.0
ft
Permanent Grass Linina:
Temporary Lining
Left Side Slope, r =
3.0
hori ontal :1 vertical
Grass Retardance=
D
Temporary Lining
Used (Y/N)=
Y
Right Side Slope, a =
3.0
hori ontal :1 vertical
K=
34.6
RECP Product Name =
NA Green - Curlex I, or equal
V_ =
4.5
ft/sec
Manning s Coefficient, n =
0.035
Minimum Freeboard=
0.5
ft
r,,_=
0.60
Ib/ft'
rare=
1.55 Ib/ft,
Maximum Channel Slope, S_ =
0.020
ft/ft
Bare Ground (If Temporary Liner Not Used
Minimum Channel Slope, S do =
0.001
Wit
Manning s Coefficient, n =
0.020
V_ =
2.0
ft/sec
Normal Depth
Depth of Flow
Manning
Area
Wetted
Hydraulic
Top
Hydraulic
Average
Flow
Froude
Maximum
Allowable
Factor
(Norm. Depth)
Roughness
of Fl ow
Perimeter
Radius
Width
Depth
Velocity
Rate
Number
Shear Stress
Vel ocity(V)or
of Safety
Comment
Y„
Coefficient
A
P
R=ArP
T
D=A7T
V
O
F, (Normal)
rd
Sh. Stress (S)
vll,,,,/v„ or
ft
n
ft,
ft
ft
ft
ft
ft/s
ft3/s
#
Ib/ft'
Used
z-,I'd
02
Maximum Slope:
0.46
0.035 2.47
6.91
0.36
6.76
0.37 3.04
7.5
0.88
0.6
S
2.7 0.K.
Minimum Slope:
1.02
0.035 7.15
10.42
0.69
10.09
0.71 1.05
7.5
0.22
0.1
S
24.5 O.K.
025
Maximum Slope:
1.17
0.054 8.73
11.37
0.77
10.99
0.79 3.29
28.7
0.65
1.5
V
1.4 0.K.
Minimum Slope:
2.63
0.068 31.37
20.67
1.52
19.81
1.58 0.91
28.6
0.13
0.2
V
4.9 0.K.
Critical Depth
Depth of Flow
Manning
Area
Wetted
Hydraulic
Top
Hydraulic
Section
Flow
Average
Froude
Uniform -Flow
(Crit. Depth)
Roughness
of Flow
Perimeter
Radius
Width
Depth
Factor
Rate
Velocity
Number
Critical Slope
Comment
Y
Coefficient
A
P
R=A/P
T
O-AiT
O
V,
F, (Qifical)
S,
ft
n
ft,
ft
ft
ft
ft
ft25
ft'/s
ft/s
#
ft/ft
02
0.43
0.035 2.24
6.69
0.34
6.55
0.34 1.31
7.4
3.32
1.00
0.026
Slopes Near Sc- Check Freeboard.
C25
0.92
0.051
6.17
9.79
0.63
9.49
0.65 4.98
28.2
4.58
1.00
0.045
FI ow Is Stable.
Determination of Minimum Channel Depth & Top Width (Based
on 025)
Maximum Slope
Minimum Slope
Minimum
Minimum
Minimum
Minimum
Channel
Top Width
Channel
Top Width
Depth
T
Depth
T
ft
ft
ft
ft
1.67
13.99
3.13
22.81
SMITH GARDNER, INC DC- 1 DRAINAGE CHANNEL-Westside C&D Area 2

DocuSign Envelope ID: F45A7F90-6A55-4F1A-89A4-806E1A91C808
PROJECT Westside CBDLandfil l -Area 2
SHEET
5/15
JOB#
WILSON-20-1
SUBJECT Drainage Channel Analysis (Grass Lined)
DATE
10/11/2021
COMPUTED BY
SWH
Channel No.
DC-2
CHECKEDBY
WMB
Design
Parameters:
PEAK DISCHARGE, Q?=
4.1
ft'/s
Source:
HydroCAD 2-Yr 24-Hr
PEAK DISCHARGE, r225=
14.2
ftl/s
Source:
HydroCAD25-Yr24-Hr
Bottom Wdth, B=
4.0
ft
Permanent Grass Linina:
Temporary Lining
Left Side Slope, r =
3.0
hori ontal :1 vertical
Grass Retardance=
D
Temporary Lining
Used (Y/N)=
Y
Right Side Slope, a =
3.0
hori ontal :1 vertical
K=
34.6
RECP Product Name =
NA Green - Curlex I, or equal
V_ =
4.5
ft/sec
Manning s Coefficient, n =
0.035
Minimum Freeboard=
0.5
ft
r,,_=
0.60
Ib/ft'
rare=
1.55 Ib/ft,
Maximum Channel Slope, S_ =
0.020
Wit
Bare Ground (If Temporary Liner Not Used
Minimum Channel Slope, S do =
0.005
Wit
Manning s Coefficient, n =
0.020
V_ =
2.0
ft/sec
Normal Depth
Depth of Flow
Manning
Area
Wetted
Hydraulic
Top
Hydraulic
Average
Flow
Froude
Maximum
Allowable
Factor
(Norm. Depth)
Roughness
of Fl ow
Perimeter
Radius
Wdth
Depth
Velocity
Rate
Number
Shear Stress
Vel ocity(V)or
of Safety
Comment
Y„
Coefficient
A
P
R=ArP
T
D=AiT
V
O
F, (Normal)
rd
Sh. Stress (S)
vll,,,,/v„ or
ft
n
ft,
ft
ft
ft
ft
ft/s
ft3/s
#
Ib/ft'
Used
z-,I'd
02
Maximum Slope:
0.33
0.035 1.65
6.09
0.27
5.98
0.28 2.52
4.1
0.85
0.4
S
3.8 0.K.
Minimum Slope:
0.48
0.035 2.61
7.04
0.37
6.88
0.38 1.55
4.1
0.44
0.1
S
10.3 O.K.
C25
Maximum Slope:
0.87
0.061 5.75
9.50
0.61
9.22
0.62 2.45
14.1
0.55
1.1
V
1.8 0.K.
Minimum Slope:
1.31
0.069 10.39
12.29
0.85
11.86
0.88 1.37
14.2
0.26
0.4
V
3.3 0.K.
Critical Depth
Depth of Flow
Manning
Area
Wetted
Hydraulic
Top
Hydraulic
Section
Flow
Average
Froude
Uniform -Flow
(Crit. Depth)
Roughness
of Flow
Perimeter
Radius
Width
Depth
Factor
Rate
Velocity
Number
Critical Slope
Comment
Y
Coefficient
A
P
R=A/P
T
O-AiT
O
V,
F, (Qifical)
S,
ft
n
ft,
ft
ft
ft
ft
ft2s
ft'/S
ft/s
#
ft/ft
O2
0.30
0.035 1.47
5.90
0.25
5.80
0.25 0.74
4.2
2.86
1.00
0.029
Flow Is Stable.
025
0.62
0.056
3.63
7.92
0.46
7.72
1 0.47 2.49
14.1
3.89
1.00
0.061
Flow is Stable.
Determination of Minimum Channel Depth 8 Top W dth (Based
on 025)
Maximum Slope
Minimum Slope
Minimum
Minimum
Minimum
Minimum
Channel
Top Width
Channel
Top Width
Depth
T
Depth
T
ft
ft
ft
ft
1.37
12.22
1.81
14.86
SMITH GARDNER, INC DC-2 DRAINAGE CHANNEL-Westside C&D Area 2

DocuSign Envelope ID: F45A7F90-6A55-4F1A-89A4-806E1A91C808
PROJECT Westside CBDLandfil l -Area 2
SHEET
6/10
JOB#
WILSON-20-1
SUBJECT Drainage Channel Analysis (Grass Lined)
DATE
10/11/2021
COMPUTED BY
SWH
Channel No.
DC-3
CHECKEDBY
WMB
Design
Parameters:
PEAK DISCHARGE, L72=
1.9
ft'/s
Source:
HydroCAD 2-Yr 24-Hr
PEAK DISCHARGE, r225=
6.2
ftl/s
Source:
HydroCAD25-Yr24-Hr
Bottom Wdth, B=
4.0
ft
Permanent Grass Linina:
Temporary Lining
Left Side Slope, r =
3.0
hori ontal :1 vertical
Grass Retardance=
D
Temporary Lining
Used (Y/N)=
Y
Right Side Slope, a =
3.0
hori ontal :1 vertical
K=
34.6
RECP Product Name =
NA Green - Curlex I, or equal
V_ =
4.5
ft/sec
Manning s Coefficient, n =
0.035
Minimum Freeboard=
0.5
ft
r,,_=
0.60
Ib/ft'
rare=
1.55 Ib/ft,
Maximum Channel Slope, S_ =
0.020
Wit
Bare Ground (If Temporary Liner Not Used
Minimum Channel Slope, S do =
0.005
Wit
Manning s Coefficient, n =
0.020
V_ =
2.0
ft/sec
Normal Depth
Depth of Flow
Manning
Area
Wetted
Hydraulic
Top
Hydraulic
Average
Flow
Froude
Maximum
Allowable
Factor
(Norm. Depth)
Roughness
of Fl ow
Perimeter
Radius
Wdth
Depth
Velocity
Rate
Number
Shear Stress
Vel ocity(V)or
of Safety
Comment
Y„
Coefficient
A
P
R=A7P
T
D=AiT
V
O
F, (Normal)
rd
Sh. Stress (S)
vll,,,,/v„ or
ft
n
ft,
ft
ft
ft
ft
ft/s
ft3/s
#
Ib/ft'
Used
z-,I'd
C2
Maximum Slope:
0.22
0.035 1.00
5.36
0.19
5.29
0.19 1.96
2.0
0.80
0.3
S
5.8 0.K.
Minimum Slope:
0.32
0.035 1.56
5.99
0.26
5.89
0.26 1.23
1.9
0.42
0.1
S
15.8 O.K.
C25
Maximum Slope:
0.63
0.075 3.67
7.95
0.46
7.75
0.47 1.68
6.2
0.43
0.8
V
2.7 0.K.
Minimum Slope:
0.96
0.084 6.56
10.04
0.65
9.73
0.67 0.94
6.2
0.20
0.3
V
4.8 0.K.
Critical Depth
Depth of Flow
Manning
Area
Wetted
Hydraulic
Top
Hydraulic
Section
Flow
Average
Froude
Uniform -Flow
(Crit. Depth)
Roughness
of Flow
Perimeter
Radius
Width
Depth
Factor
Rate
Velocity
Number
Critical Slope
Comment
Y
Coefficient
A
P
R=A/P
T
O-AiT
O
V,
F, (Qifical)
S,
ft
n
ft,
ft
ft
ft
ft
ft25
ft'/S
ft/s
#
ft/ft
02
0.19
0.035 0.84
5.17
0.16
5.11
0.16 0.34
1.9
2.30
1.00
0.033
Flow Is Stable.
025
0.39
0.068
1.98
6.43
0.31
6.31
1 0.31 1.11
6.3
3.18
1.00
0.101
Flow is Stable.
Determination of Minimum Channel Depth & Top W dth (Based
on 025)
Maximum Slope
Minimum Slope
Minimum
Minimum
Minimum
Minimum
Channel
Top Width
Channel
Top Width
Depth
T
Depth
T
ft
ft
ft
ft
1.13
10.75
1.46
12.73
SMITH GARDNER, INC DC-3 DRAINAGE CHANNEL-Westside C&D Area 2

DocuSign Envelope ID: F45A7F90-6A55-4F1A-89A4-806E1A91C808
PROJECT Westside C&DLandfil l -Area 2
SHEET
7/15
JOB#
WILSON-20-1
SUBJECT Drainage Channel Analysis (Grass Lined)
DATE
10/11/2021
COMPUTED BY
SWH
Channel No.
DC-4
CHECKEDBY
WMB
Design
Parameters:
PEAK DISCHARGE, Q?=
10.9
ft'/s
Source:
HydroCAD 2-Yr 24-Hr
PEAK DISCHARGE, r225=
38.6
ftl/s
Source:
HydroCAD25-Yr24-Hr
Bottom Width, B =
4.0
ft
Permanent Grass Linina:
Temporary Lining
Left Side Slope, r =
3.0
hori ontal :1 vertical
Grass Retardance=
D
Temporary Lining
Used (Y/N)=
Y
Right Side Slope, a =
3.0
hori ontal :1 vertical
K=
34.6
RECP Product Name =
NA Green - Curlex I, or equal
V_ =
4.5
ft/sec
Manning s Coefficient, n =
0.035
Minimum Freeboard=
0.5
ft
r,,_=
0.60
Ib/ft'
rare=
1.55 Ib/ft,
Maximum Channel Slope, S_ =
0.020
Wilt
Bare Ground (If Temporary Liner Not Used
Minimum Channel Slope, S do =
0.005
Wit
Manning s Coefficient, n =
0.020
V_ =
2.0
ft/sec
Normal Depth
Depth of Flow
Manning
Area
Wetted
Hydraulic
Top
Hydraulic
Average
Flow
Froude
Maximum
Allowable
Factor
(Norm. Depth)
Roughness
of Fl ow
Perimeter
Radius
Width
Depth
Velocity
Rate
Number
Shear Stress
Vel ocity(V)or
of Safety
Comment
Y„
Coefficient
A
P
R=ArP
T
D=A7T
V
O
F, (Normal)
rd
Sh. Stress (S)
vll,,,,/v„ or
ft
n
ft,
ft
ft
ft
ft
ft/s
ft3/s
#
Ib/ft'
Used
z-,I'd
02
Maximum Slope:
0.57
0.035 3.22
7.57
0.42
7.39
0.44 3.40
10.9
0.91
0.7
S
2.2 O.K.
Minimum Slope:
0.82
0.035 5.25
9.15
0.57
8.89
0.59 2.08
10.9
0.48
0.3
S
6.1 O.K.
025
Maximum Slope:
1.31
0.051 10.45
12.32
0.85
11.89
0.88 3.69
38.5
0.69
1.6
V
1.2 0.K.
Minimum Slope:
1.92
0.057 18.82
16.17
1.16
15.55
1.21 2.05
38.6
0.33
0.6
V
2.2 0.K.
Critical Depth
Depth of Flow
Manning
Area
Wetted
Hydraulic
Top
Hydraulic
Section
Flow
Average
Froude
Uniform -Flow
(Grit. Depth)
Roughness
of Flow
Perimeter
Radius
Width
Depth
Factor
Rate
Velocity
Number
Critical Slope
Comment
Y
Coefficient
A
P
R=A/P
T
O-AiT
O
V,
F, (Qifical)
S,
ft
n
ft,
ft
ft
ft
ft
ft2s
ft'/S
ft/s
#
ft/ft
02
0.54
0.035 3.00
7.38
0.41
7.21
0.42 1.93
11.0
3.66
1.00
0.025
Slopes Near Sc- Check Freeboard.
C25
1.09
0.049
7.87
10.86
0.72
10.51
1 0.75 6.81
38.7
4.91
1.00
0.040
FI ow Is Stable.
Determination of Minimum Channel Depth & Top Width (Based
on 025)
Maximum Slope
Minimum Slope
Minimum
Minimum
Minimum
Minimum
Channel
Top Width
Channel
Top Wdth
Depth
T
Depth
T
ft
ft
ft
ft
1.81
14.89
2.42
18.55
SMITH GARDNER, INC D04 DRAINAGE CHANNEL-Westside C&D Area 2

DocuSign Envelope ID: F45A7F90-6A55-4F1A-89A4-806E1A91C808
PROJECT Westside CBDLandfil l -Area 2
SHEET
8/15
JOB#
WILSON-20-1
SUBJECT Drainage Channel Analysis (Grass Lined)
DATE
10/11/2021
COMPUTED BY
SWH
Channel No.
DC-5
CHECKEDBY
WMB
Design
Parameters:
PEAK DISCHARGE, L72=
9.4
ft'/s
Source:
HydroCAD 2-Yr 24-Hr
PEAK DISCHARGE, r225=
47.1
ftl/s
Source:
HydroCAD25-Yr24-Hr
Bottom Width, B =
4.0
ft
Permanent Grass Linina:
Temporary Lining
Left Side Slope, r =
3.0
hori ontal :1 vertical
Grass Retardance=
D
Temporary Lining
Used (Y/N)=
Y
Right Side Slope, a =
3.0
hori ontal :1 vertical
K=
34.6
RECP Product Name =
NA Green - Curlex I, or equal
V_ =
4.5
ft/sec
Manning s Coefficient, n =
0.035
Minimum Freeboard=
0.5
ft
r,,_=
0.60
Ib/ft'
rare=
1.55 Ib/ft,
Maximum Channel Slope, S_ =
0.020
ft/ft
Bare Ground (If Temporary Liner Not Used
Minimum Channel Slope, S do =
0.005
Wit
Manning s Coefficient, n =
0.020
V_ =
2.0
ft/sec
Normal Depth
Depth of Flow
Manning
Area
Wetted
Hydraulic
Top
Hydraulic
Average
Flow
Froude
Maximum
Allowable
Factor
(Norm. Depth)
Roughness
of Fl ow
Perimeter
Radius
Width
Depth
Velocity
Rate
Number
Shear Stress
Vel ocity(V)or
of Safety
Comment
Y„
Coefficient
A
P
R=A7P
T
D=AiT
V
O
F, (Normal)
rd
Sh. Stress (S)
vll,,,,/v„ or
ft
n
ft,
ft
ft
ft
ft
ft/s
ft3/s
#
Ib/ft'
Used
z-,I'd
02
Maximum Slope:
0.52
0.035 2.89
7.29
0.40
7.12
0.41 3.25
9.4
0.90
0.6
S
2.4 0.K.
Minimum Slope:
0.75
0.035 4.69
8.74
0.54
8.50
0.55 1.99
9.3
0.47
0.2
S
6.6 O.K.
025
Maximum Slope:
1.43
0.050 11.85
13.04
0.91
12.58
0.94 3.99
47.3
0.72
1.8
V
1.1 0.K.
Minimum Slope:
2.08
0.055 21.30
17.16
1.24
16.48
1.29 2.21
47.2
0.34
0.6
V
2.0 0.K.
Critical Depth
Depth of Flow
Manning
Area
Wetted
Hydraulic
Top
Hydraulic
Section
Flow
Average
Froude
Uniform -Flow
(Crit. Depth)
Roughness
of Flow
Perimeter
Radius
Width
Depth
Factor
Rate
Velocity
Number
Critical Slope
Comment
Y
Coefficient
A
P
R=A/P
T
O-AiT
O
V,
F, (Qifical)
S,
ft
n
ft,
ft
ft
ft
ft
ft2s
ft'/S
ft/s
#
ft/ft
02
0.49
0.035 2.68
7.10
0.38
6.94
0.39 1.67
9.5
3.53
1.00
0.025
Slopes Near Sc- Check Freeboard.
C25
1.21
0.047
9.23
11.65
0.79
11.26
0.82 8.36
47.4
5.14
1.00
0.037
Flow Is Stable.
Determination of Minimum Channel Depth & Top Width (Based
on 025)
Maximum Slope
Minimum Slope
Minimum
Minimum
Minimum
Minimum
Channel
Top Width
Channel
Top Wdth
Depth
T
Depth
T
ft
ft
ft
ft
1.93
15.58
2.68
19.48
SMITH GARDNER, INC DC-5 DRAINAGE CHANNEL-Westside C&D Area 2

DocuSign Envelope ID: F45A7F90-6A55-4F1A-89A4-806E1A91C808
PROJECT Westside CBDLandfil l -Area 2
SHEET
11/15
JOB#
WILSON-20-1
SUBJECT Drainage Channel Analysis (Grass Lined)
DATE
10/11/2021
COMPUTED BY
SWH
Channel No.
DC-6
CHECKEDBY
WMB
Design
Parameters:
PEAK DISCHARGE, Q?=
10.5
ft'/s
Source:
HydroCAD 2-Yr 24-Hr
PEAK DISCHARGE, r225=
51.0
ftl/s
Source:
HydroCAD25-Yr24-Hr
Bottom Width, B =
4.0
ft
Permanent Grass Linina:
Temporary Lining
Left Side Slope, r =
3.0
hori ontal :1 vertical
Grass Retardance=
D
Temporary Lining
Used (Y/N)=
Y
Right Side Slope, a =
3.0
hori ontal :1 vertical
K=
34.6
RECP Product Name =
NA Green - Curlex I, or equal
V_ =
4.5
ft/sec
Manning s Coefficient, n =
0.035
Minimum Freeboard=
0.5
ft
r,,_=
0.60
Ib/ft'
rare=
1.55 Ib/ft,
Maximum Channel Slope, S_ =
0.020
ft/ft
Bare Ground (If Temporary Liner Not Used
Minimum Channel Slope, S do =
0.005
Wit
Manning s Coefficient, n =
0.020
V_ =
2.0
ft/sec
Normal Depth
Depth of Flow
Manning
Area
Wetted
Hydraulic
Top
Hydraulic
Average
Flow
Froude
Maximum
Allowable
Factor
(Norm. Depth)
Roughness
of Fl ow
Perimeter
Radius
Width
Depth
Velocity
Rate
Number
Shear Stress
Vel ocity(V)or
of Safety
Comment
Y„
Coefficient
A
P
R=ArP
T
D=AiT
V
O
F, (Normal)
rd
Sh. Stress (S)
vll,,,,/v„ or
ft
n
ft,
ft
ft
ft
ft
ft/s
ft3/s
#
Ib/ft'
Used
z-,I'd
02
Maximum Slope:
0.56
0.035 3.14
7.51
0.42
7.33
0.43 3.37
10.6
0.91
0.7
S
2.2 0.K.
Minimum Slope:
0.80
0.035 5.08
9.03
0.56
8.77
0.58 2.05
10.4
0.47
0.2
S
6.2 O.K.
C25
Maximum Slope:
1.47
0.049 12.43
13.33
0.93
12.85
0.97 4.10
51.0
0.73
1.8
V
1.1 0.K.
Minimum Slope:
2.14
0.054 22.38
17.57
1.27
16.87
1.33 2.28
51.0
0.35
0.7
V
2.0 0.K.
Critical Depth
Depth of Flow
Manning
Area
Wetted
Hydraulic
Top
Hydraulic
Section
Flow
Average
Froude
Uniform -Flow
(Crit. Depth)
Roughness
of Flow
Perimeter
Radius
Width
Depth
Factor
Rate
Velocity
Number
Critical Slope
Comment
Y
Coefficient
A
P
R=A/P
T
O-AiT
O
V,
F, (Qifical)
S,
ft
n
ft,
ft
ft
ft
ft
ft25
TO
ft/s
#
ft/ft
02
0.53
0.035 2.93
7.32
0.40
7.15
0.41 1.87
10.6
3.63
1.00
0.025
Slopes Near Sc- Check Freeboard.
025
1.26
0.047
9.75
11.94
0.82
11.53
0.85 8.96
50.8
5.22
1.00
0.035
FI ow Is Stable.
Determination of Minimum Channel Depth & Top Width (Based
on 025)
Maximum Slope
Minimum Slope
Minimum
Minimum
Minimum
Minimum
Channel
Top Width
Channel
Top Wdth
Depth
T
Depth
T
ft
ft
ft
ft
1.97
15.85
2.64
19.87
SMITH GARDNER, INC DC-6 DRAINAGE CHANNEL-Westside C&D Area 2

DocuSign Envelope ID: F45A7F90-6A55-4F1A-89A4-806E1A91C808
PROJECT Westside CBDLandfil l -Area 2
SHEET
12/15
JOB#
WILSON-20-1
SUBJECT Drainage Channel Analysis (Grass Lined)
DATE
10/11/2021
COMPUTED BY
SWH
Channel No.
DC-7
CHECKEDBY
WMB
Design
Parameters:
PEAK DISCHARGE, L72=
9.3
ft3/s
Source:
HydroCAD 2-Yr 24-Hr
PEAK DISCHARGE, r225=
40.8
ft3/s
Source:
HydroCAD25-Yr24-Hr
Bottom Width, B =
4.0
ft
Permanent Grass Linina:
Temporary Lining
Left Side Slope, r =
3.0
hori ontal :1 vertical
Grass Retardance=
D
Temporary Lining
Used (Y/N)=
Y
Right Side Slope, a =
3.0
hori ontal :1 vertical
K=
34.6
RECP Product Name =
NA Green - Curlex I, or equal
V_ =
4.5
ft/sec
Manning s Coefficient, n =
0.035
Minimum Freeboard=
0.5
ft
r,,_=
0.60
Ib/ft3
rare=
1.55 Ib/ft3
Maximum Channel Slope, S_ =
0.020
ft/ft
Bare Ground (If Temporary Liner Not Used
Minimum Channel Slope, S do =
0.005
Wit
Manning s Coefficient, n =
0.020
V_ =
2.0
ft/sec
Normal Depth
Depth of Flow
Manning
Area
Wetted
Hydraulic
Top
Hydraulic
Average
Flow
Froude
Maximum
Allowable
Factor
(Norm. Depth)
Roughness
of Fl ow
Perimeter
Radius
Width
Depth
Velocity
Rate
Number
Shear Stress
Vel ocity(V)or
of Safety
Comment
Y„
Coefficient
A
P
R=ArP
T
D=A7T
V
O
F, (Normal)
rd
Sh. Stress (S)
vll,,,,/v„ or
ft
n
ft,
ft
ft
ft
ft
ft/s
ft3/s
#
Ib/ft3
Used
z-,I'd
02
Maximum Slope:
0.52
0.035 2.86
7.26
0.39
7.09
0.40 3.23
9.2
0.90
0.6
S
2.4 0.K.
Minimum Slope:
0.75
0.035 4.65
8.71
0.53
8.47
0.55 1.98
9.2
0.47
0.2
S
6.7 O.K.
025
Maximum Slope:
1.34
0.051 10.81
12.51
0.86
12.07
0.90 3.77
40.7
0.70
1.7
V
1.2 0.K.
Minimum Slope:
1.96
0.056 19.44
16.43
1.18
15.79
1.23 2.10
40.8
0.33
0.6
V
2.1 0.K.
Critical Depth
Depth of Flow
Manning
Area
Wetted
Hydraulic
Top
Hydraulic
Section
Flow
Average
Froude
Uniform -Flow
(Grit. Depth)
Roughness
of Flow
Perimeter
Radius
Width
Depth
Factor
Rate
Velocity
Number
Critical Slope
Comment
Y
Coefficient
A
P
R=A/P
T
O-AiT
O
V,
F, (Qifical)
S,
ft
n
ft2
ft
ft
ft
ft
ft25
ft3/S
ft/s
#
ft/ft
02
0.49
0.035 2.65
7.07
0.37
6.91
0.38 1.64
9.3
3.51
1.00
0.025
Slopes Near Sc- Check Freeboard.
025
1.12
0.048
8.19
11.05
0.74
10.69
0.77 7.17
40.7
4.97
1.00
0.039
FI ow Is Stable.
Determination of Minimum Channel Depth 8 Top Width (Based
on 025)
Maximum Slope
Minimum Slope
Minimum
Minimum
Minimum
Minimum
Channel
Top Width
Channel
Top Wdth
Depth
T
Depth
T
ft
ft
ft
ft
1.84
15.07
2.46
18.79
SMITH GARDNER, INC DC-7 DRAINAGE CHANNEL-Westside C&D Area 2

DocuSign Envelope ID: F45A7F90-6A55-4F1A-89A4-806E1A91C808
PROJECT Westside C&D Landfil I - Area 2 SHEET 15115
JOB# WiLSCN-20-1
SUBJECT Drainage Channel Analysis (TRM Lined) DATE 7/17/2020
COMPUTED BY SWH
Channel No. Final Cover Side Slope Swale CHECKED BY WMB
Design Parameters:
PEAK DISCHARGE, Q25=
21.2
ft'/s
Source: HydroCAD 25-Yr 24-Hr
Bottom Width, B =
0.0
ft
Turf Reinforcement Matti ng(TRM) Li ni no:
Left Side Slope, f =
1.5
hori ontal :1 vertical
Grass Retardance = D
Rght Side Slope, z =
4.0
hori ontal :1 vertical
K = 34.6
TRM Product Name = Propex - Landlok TRM 435, or equal
Minimum Freeboard =
0.5
ft
z�iow = 5.0 lb/ft2
Maximum Channel Slope, S... =
0.040
ft/ft
Minimum Channel Slope, Sm =
0.020
ft/ft
Normal Depth
Depth of Flow
(Norm. Depth)
Y
ft
Manning s
Roughness
Coefficient
n
Area
of Flow
A
ft2
Wetted
Perimeter
P
ft
Hydraulic
Radius
R-,WP
ft
Top
Width
T
ft
Hydraulic
Depth
D-WT
ft
Average
Velocity
1/1Q
ft/s
Flow
Rate
ft'/s
Froude
Number
F, (Norma/)
#
Maximum
Shear Stress
zo
Ib/ft2
Factor
of Safety
1a /To
Comment
Maximum Slope:
1.36 0.052 5.09 8.06 0.63 7.48 0.68 4.22 21.4 0.90 3.4 1.5 O.K.
Minimum Slope:
1.58 0.055
6.87 9.36
0.73 8.69 0.79 3.11 21.3 0.62 2.0 2.5 O.K.
_.._.. ....._...__ __...._.... .....
......._.._...._.............._._............._._..................
.......... ... ................... .............. .__. ._._.............. _................ _................._........... ...._._._.... ......_._... ...._...
Critical Depth
Depth of Flow
(CYit. Depth)
Y
ft
Manning s
Roughness
Coefficient
n
Area
of Flow
A
ft2
Wetted
Perimeter
P
ft
Hydraulic
Radius
R-,WP
ft
Top
Width
T
ft
Hydraulic
Depth
D-WT
ft
Section
Factor
ADO2
ft-
Flow
Rate
Q
ft'/s
Average
Velocity
V
ft/s
Froude
Number
F, (0YiN-1)
#
Uniform -Flow
Critical Slope
S,
ft/ft
Comment
1.29
0.051
4.61
7.67
0.60
7.12
0.65
3.71
21.1
4.57
1.00
0.048
Slopes Near Sc- Check Freeboard.
......................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................_.
Determination of Minimum Channel Depth & Top Width
Maximum
Slope
Minimum
Slope
Minimum
Minimum
Minimum
Minimum
Channel
Top Width
Channel
Top Width
Depth
T
Depth
T
ft
ft
ft
ft
1.86
10.23
2.08
11.44

0
(D
0_
0
c
w
c
2)
in
0
U
O

DocuSign Envelope ID: F45A7F90-6A55-4F1A-89A4-806E1A91C808
IL �14N. Boylan Avenue, Raleigh, NC
PROJECT Westside C&D Landfill -Area 2 SHEET
SUBJECT Down Pipe Analysis JOB#
TEL I WEB
919.828.0577 1 www.smithgardnerinc.com
1 OF 3
WI LSON-20-1
DATE 7/ 20/ 2020
COMPUTED BY SWH
CHECKED BY WMB
OBJECTIVE: To design down pipes to handle the peak discharge from the design storm.
REFERENCES: Debo, T.N., and Reese, A.J. (1995), Municipal Storm Water Management, Lewis Publishers, Boca
Raton, FL.
Malcom, H. Rooney (1989 & 2003 Supplement), Elements of Urban Stormwater Design, NC State
Univ., Raleigh, NC.
ANALYSIS: The following approach is used in the design of rain gutters and down pipes:
1. Determine the peak discharge from the design storm(s). Use the Rational Method.
2. For each pipe si e, determine the maximum area (A), to handle the predicted peak
discharge (Q) with an added factor of safety. Analy e rain gutters and down pipes based
on partial flow to determine flow depth and velocity then compare the full flow capacity of
each pipe si e with the calculated peak flow rate to verify the desired factor of safety.
Analy e down pipe inlets as a culvert under inlet control.
CALCULATIONS:
Down Pipe Inlets (Inlet Control
Determine C, ,
For SG:
Qmax = 0.372CdD(Z)3/2 (Malcolm Equation III-13)
For S:
i/z
Qmax = 0.0437CdD2 Z — � (Malcolm Equation III-13)
where: Gmax = flow capacity of inlet (cfs)
height of water above pipe invert (ft)
allowable headwater depth (HW)
G d = coefficient of discharge
G = inside diameter of pipe (in)
Determine Factor of Safety_(FSY
FS = Qmax
Q
Iterate the drainage area (A) to each drainage structure that Cmax/Q: the desired factor of safety.

DocuSign Envelope ID: F45A7F90-6A55-4F1A-89A4-806E1A91C808
PRQIECT Westside C&D Landfill -Area 2 SHEET
SUBJECT Down Pipe Analysis JOB #
Down Pipes:
2 OF
WI LSON-20-1
3
DATE 7/20/2020
COMPUTED BY SWH
CHECKED BY WMB
Determine Flow Capacity of Pipe:
O.463D8/3Sliz
Amax = (D&R Equation 8.24)
n
where: Gmax = flow capacity of pipe (cfs)
G = inside diameter of pipe (ft)
5 = pipe slope (ft/ft)
n = Manning s roughness coefficient
Determine Factor of Safety (FS)�
FS _ Q.
�7 Q)
Iterate the drainage area (A) to each drainage structure that G ,a,/Q>. the desired factor of safety.
Determine Flow Depth:
h \\
= Z I 1 — cos( 0)) D (D&R Equation 8.29)
where: h= flow depth (inches)
0 = central angle (degrees)
39L vz 11/2
(D&R Equation 8.28)
R = constant
K = 0.673QnD-813S-1i2 (D&R Equation 8.27)
Determine Flow Velocity:
v= = Q
AD&R Equation 8.30 for A
A Dz (B— sing) ( q )
8
where: t/ = flow velocity (ft/sec)
A = cross -sectional area of flow (ft)

DocuSign Envelope ID: F45A7F90-6A55-4F1A-89A4-806E1A91C808
PROJECT Westside C&D Landfill -Area 2
SUBJECT Down Pipe Analysis (CPE Pipe)
Input Parameters:
Manning s Rougness Coefficient = 0.012 -- CPE Pipe (Type S- Use 0.012 Type C- Use 0.02)
Runoff Coefficient = 0.60
Rainfall Intensity= 9.23 IN/HR--- 50 YR-5MIN STORM
Allowable Headwater Depth (Above Pipe Invert) (Down Pipe Inlets) = 3.0 FEET
Orifice Coef. Of Discharge (Down Pipe lnl ets)= 0.6 TYPICAL
SHEET
3/3
JOB #
WILSCN-20-1
DATE
7/20/2020
COMPUTED BY
SWH
CHECKED BY
WMB
Down Pipe
Inlets
ID
Drainage Area
(AC)
(Q)
(CFS)
Pipe I.D.
(IN)
Area
(SF)
A.)
(CFS)
Factor of Safety
( /=1.10)
Max. Area - 12
0.95
5.26
12.0
0.79
5.97
1.13
Max. Area - 15
1.45
8.03
15.0
1.23
9.09
1.13
Max. Area - 18
2.05
11.35
18.0
1.77
12.74
1.12
Max. Area - 24
3.40
18.83
24.0
3.14
21.36
1.13
Down Pipes
ID
Drainage Area
(A(-;)
RunoffVolume
(Q)
((;FS)
Pipe I.D.
(IN)
Pipe Slope
( )
Flow Capacity
A.)
(CF5)
Factor of Safety
( /=mu)
K
(CONSTANT)
q
( 265`)
Flow Depth
(IN)
Flow Area
(SF)
Flow Velocity
(FPS)
Max. Area - 12
3.10
17.17
12.0
25
19.29
1.12
0.277
233
8.66
0.61
28.30
Max. Area - 15
5.65
31.29
15.0
25
34.98
1.12
0.279
233
10.86
0.95
32.87
Max. Area - 18
9.30
51.50
18.0
25
56.88
1.10
0.282
235
13.16
1.38
37.20
Max. Area - 24
20.10
111.31
24.0
25
122.49
1.10
0.283
236
17.60
2.47
45.09
SMITH GARGNER, INC.
CPE Pipe
DOWN PIPE SG

0
(D
0_
0
c
w
c
2)
in
0
U
O

DocuSign Envelope ID: F45A7F90-6A55-4F1A-89A4-806E1A91C808
TEL I WEB
14 N. Boylan Avenue, Raleigh, NC27603 919.828.0577 1 www.smithciardnerinc.com
PROJECT Westside C&D Landfill -Area 2 SHEET 1 OF 8 DATE 7/20/2020
COMPUTED BY SWH
SUBJECT Sediment Basin Analysis JOB # WILSON-20-1 CHECKED BY WMB
OBJECTIVE_ To design a sediment basin(s) to satisfyerosion and sediment control requirements and to handle the flow
from the design storm.
REFERENCES: American Concrete Pipe Association (1996), "Design Data 41 - Manhole Floatation", ACPA, Irving, T .
Malcom, H. Rooney (1989 & 2003 Supplement), Elements of Urban Stormwater Design, NC State Univ.,
Raleigh, NC.
North Carolina Division of Land Resources (2013 Updates), North Carolina Erosion & Sediment Control
Planning & Design Manual, Raleigh, NC.
Virginia Department of Conservation and Recreation (1992), Virginia Erosion & Sediment Control
Handbook, Third Edition, Richmond, VA.
ANALYSIS: The following approach is used to properly si a and evaluate each sediment basin:
1. Design for Wet (If Applicable) and Dry Storage.
2. Route Design Storm.
3. Design Outlet Structures (Design Riser/Barrel Structures and Perform Riser Base Calculations,
Anti -Seepage Collar Calculations, & Emergency Spillway Calculations).
CALCULATIONS:
- Design for Wet (If Applicable) and Dry Storage:
Determine required wet (if applicable) and dry storage volumes based on applicable erosion and sedimentation
control requirements.
If applicable, calculate the desired surface area at the principal spillway. For some locations:
A = 0.01Q,
where: A = desired surface area (acres)
6, = peak discharge from design storm (cfs)
(Use 25-yr 24-hr storm)
Set up a stage -storage relationship for the proposed basin as shown below. Based on this relationship and the
required volume(s) and/or desired surface area, determine the required wet storage (if applicable) and dry storage
elevations. Alternatively the elevation(s) can be determined from a graphical stage -storage relationship.
S = KZ'
(Malcom Eq. III-7)
where: 5 = storage volume (ft)
R,, b = linear regression constants describing the stage -storage relationship
= stage referenced tothe bottom elevation included in the analysis (ft)
Set sediment basin cleanout elevation.
SMITH GARDNER, INC. SED BASIN- GEN ERAL-Westside C&D LF Area 2

DocuSign Envelope ID: F45A7F90-6A55-4F1A-89A4-806E1A91C808
PROJECT Westside C&D Landfill -Area 2 SHEET 2 OF 8
SUBJECT Sediment Basin Analvsis
JOB# WILSON-20-1
DATE 7/20/2020
COMPUTED BY SWH
CHECKED BY WMB
Si a the outlet device to release the dry storage volume (WW over the desired drawdown period (typically this is a
minimum of 24 hours). Use the following equation:
A 2h (from Original Edition of NCE&SCP&DM)
A = s
° TCd(20,428)
where: A , = surface area of dewaterinq hole(s) (ft2)
A a = surface area of basin (at principal spillway) (ft)
h = average head of water above hole (_ (elev. of principal spillway- elev. of wet storage
or (if not applicable) bottom of basin)/2) (ft)
C o = coefficient of contraction (=0.60)
7 = detention time (hrs.) (vary over recommended limits)
Select a standard pipe si a and number of holes. Verifythat the pro ected drawdown period is within the
recommended limits.
Where desired, si e a drain for the basin for maintenance. The drain should dewater the basin (to principal
spillway) within 24 hours. Use the above equation to determine A. of the basin drain. The inlet of the drain should
be protected from the sediment storage one.
Evaluate basin shape. Compare with the recommended length to width ratio. If this ratio is not achieved, the basin
should be modified or baffles should be added as required.
- Route Design Storm:
Route the design storm through the basin and determine the maximum pool elevation and the peak discharge (via
HydroCAD, spreadsheet methods, or other). Depending on local requirements, multiple design storms may need
to be considered and the peak discharge may need to be compared with the pre -development value.
Based on the peak stage of the design storm, check settling efficiency of the design particle. The design particle is
typically40 microns (0.04 mm) (within silt si a criteria).
Settling Velocity of resign Particle
V = g �(S S _ 11�1d2 (Malcom Eq. IV-3)
° 18 \ v J
where: 1/' = settling velocity (ft/s) - convert from (m/s)
9 = gravitational acceleration (m/s2)
55 = specific gravity of design particle
v = kinematic viscosity ofthefluid(m2/s)
(= 1.14 x 10-6 m2/s 16C- Ref. Streeter, 1975)
a = diameter of design particle (m)
Surface Area
AS = bKSZ(b-1) (Malcom Eq. IV-7)
where: A, = surface area at given stage ( ) (ft)
K,,b = linear regression constants describing the stage -storage relationship
SMITH GARDNER, INC. SED BASIN- GEN ERAL-Westside C&D LF Area 2

DocuSign Envelope ID: F45A7F90-6A55-4F1A-89A4-806E1A9lC808
PROJECT Westside C&D Landfill -Area 2
SUBJECT Sediment Basin Analvsis
Settling Efficiency
E=1-IVoAs I]-N
1+ NQJ
SHEET 3 OF 8
JOB# WILSON-20-1
(Malcom Eq. IV-1)
DATE 7/20/2020
COMPUTED BY SWH
CHECKED BY WMB
where: E = settling efficiency (decimal fraction - convert to )
A a = surface area at given stage ( ) (ft)
N = number of effective cel Is (N = 2 with forebay)
G = discharge at given stage ( ) (cfs)
- Design of Outlet Structures:
Design riser/barrel structures based on information used in routing the design storm.
Design base for riser structure to resist design uplift force. Base must have a buoyant weight of at least the design
uplift force. If a concrete riser structure is used, the buoyant weight of the riser can be accounted for in the
calculations.
Design Uplift Force (IF)
T F = (FS)Vxtse,-Yxzo — Wnrse,- —WTop — Wsotr — Rsojt (from VAE&SCH Spec. 3.14)
where: TF = design uplift force (Ibs)
FS = factor of safety (use 1.25)
URiser = interior volume of the riser (ft2) (base elevation to principal spil lwav elevation)
VH2C = density of water (62.4 pcf)
WRiser buoyant weight of riser (not including base or top) (Ibs)
WTop = buoyant weight of riser top (Ibs)
WSW = buoyant weight of soil backfill around riser (above base pro ection) (Ibs)
Rso;i = sliding resistance of soil backfill around riser (Ibs)
See American Concrete Pipe Association Design Data 41 for more information.
Volume of Concrete for Base
vcoa = (from VAE&SCH Spec. 3.14)
W,_,a (150 — 62.4)
where: I/C." = volume of concrete (ft)
1+C""6 = buoyant weight of concrete (150 - 62.4 = 87.6 Ibs)
Anti -Seepage Collar(s)
Determine anti -seepage collar requirements based on the following equation. Alternatively, a filter
diaphragm maybe designed.
LS = y(z + 4)1
1 + 0.25 — s) 'I (VA E&SC Handbook p. III-102)
where: L 5 = length of pipe in the saturated one (ft)
y = distance from barrel invert to riser crest (ft)
= slope of upstream embankment( HAV)
s = pipe slope (ft/ft)
SMITH GARDNER, INC. SED BASIN-GENERAL-Westside C&D LF Area 2

DocuSign Envelope ID: F45A7F90-6A55-4F1A-89A4-806E1A91C808
PROJECT Westside C&D Landfill -Area 2
SUBJECT Sediment Basin Analvsis
SHEET 4 OF 8
JOB # WILSON-20-1
DATE 7/20/2020
COMPUTED BY SWH
CHECKED BY WMB
Determine Ls and use design chart to determine anti -seepage collar requirements. If more than one col lar is used,
the spacing between collars should be 14 times the pro ection (P) of the collar above the barrel. The first collar
should beset at 2P from the riser or a minimum length to bury collar in slope.
Emergency Spillway
Design crest length of emergency spillway to handle flow from the design storm using the following equation.
Determine peak flow from stormwater routing program. If applicable, design outlet channel as a drainage channel
or rock chute.
QP = C"LH3'2 (Malcom Eq. 1-6)
where: C F = peak discharge from design storm (cfs)
C W = weir coefficient (=3.0 for free overfal I )
L = length of weir (ft)
h = driving head (ft) (=allowable headwater above crest of weir or calculated
value from stormwater routing program)
SMITH GARNER, INC. SED BASIN-GENERAL-Westside C&D LF Area 2

DocuSign Envelope ID: F45A7F9O-6A55-4F1A-89A4-8O6E1A91C8O8
PROJECT
SUBJECT
Westside C&D Landfill -Area 2
Sediment Basin Analysis
SHEET
JOB#
DATE
COMPUTED BY
CHECKED BY
518
WILSCN-20-1
10/12/2021
SWH
WMB
Basin No.:
Basin 1
DESIGN FOR WET
Areas Draining Into
(IF APPLICABLE)
Basin•
AND DRY STORAGE•
Area
Drainage Area (acres)
Drainage Area
25.0
Total = 25.0 Acres
Basin Requirements:
Wet Storage,
Required Storage Capacity (fta/Ac.)= 0Enter "C" if Not Applicable.
Required Storage Capacity (ft3)= 0
Required Depth of Wet Storage (ft)= 0.0 Enter "0" if Not Applicable.
Dry Storaoe:
Required Storage Capacity (ft0/Ac.)= 1,800 To Crest of Principal Spillway
Required Storage Capacity (ft') = 45,000
Multipier
( )for Desired Surface Area (Gpx )= 0.01 At Crest of Principal Spillway
Peak Discharge into Basin (Op) (cfs)=� 91.1 From HydroCAD- 25-Yr, 24-Hr. Storm
Desired Surface Area(Ac)= 0.91
Desired Surface Area (ft2)= 39,683
Determine Stage
-Storage Function:
Contour
Area Area Incremental Cumulative Stage
ITS
In
eat
(ft') (acres) Volume (ft') Volume(ft')(ft)
92
32,400 0.74 0 0.0
94
42,000 0.96 74,400 74,400 2.0
11.22
0.69
2.01
96
51,300 1.18 93,300 167,700 4.0
12.03
1.39
3.95
98
60,900 1.40 112,200 279,900 6.0
12.54
1.79
6.05
Linear Regression Constants:
Ks= 32,150 Storage=32150 1.2
b= 1.20
*CAUTION: CHECK INPUT FOR REGRESSION ANALYSIS?
Stage -Surface Area Relationship
Stage -Storage Relationship
99
99
98
98
97
97
96
96
95
= 95
9
9
y 94
ra 94
93
93
92
92
91
91
0
10,000 20,000 30,000 40,000 50,000 60,000 70,000 0
50.000
100,000 150,000 200,000
250,000 300,000
Surface Area (sf)
Storage (cf)
SMITH 6ARONE INC Besln 1 SED BASIN-GENERAL-Wsstside C&D LF Nee 2

DocuSign Envelope ID: F45A7F9O-6A55-4F1A-89A4-8O6E1A91C8O8
PROJECT Westside C&D Landfill -Area 2
SUBJECT Sediment Basin Analysis
Basin Design Elevations:
Elev. of Bottom of Basin (ft) =
92.0
Wet Storage,
Required Storage Capacity (fta)=
0
Min. Elev. of Wet Storage (Permanent Pool) =
92.0
Selected Elev. of Wet Storage (Permanent Pool)=
92.0 O.K.
Actual Wet Storage Volume (fta)=
0 O.K.
Dry Storage
Required Storage Capacity (ft') _
Min. El ev. of Pr l ncipal Spil lway(ft)=
Selected El ev. of Principal Spil lway(ft)=
Actual Total Storage Volume (ft') _
Desired Surface Area (ft') _
Actual Surface Area at Principal Spillway (ft') _
geanout
Cleanout Requirement( of Wet Storage)=
Cleanout Requirement( of Total Storage)=
Basin Cleanout Volume (ft')_
Basin Cleanout Elevation (ft)=
Dewatering of Dry Storage:
Option: Fairdoth Skimmer
Actual Total Storage Volume to Dewater (ft') _
Required Skimmer Si a (in)=
Required Orifice Diameter (in)=
Dewatering Rate (cis) _
45,000 = Required Dry Storage + Actual Wet Storage
93.3
96.0 O.K.
170,260 O.K.
39,683
51.182 O.K.
0 Enter "0" if Not Applicable
50
85,130 Based on 50%of Total Storage Volume
94.2
170,260 =Volume at Principal Spillway
8.0 From www.fairclothskimmer.com Based on 3 Day Drawdown
6.0 From www.fairclothskimmer.com Based on 3 Day Drawdown
1.13 Fromwww.fairclothskimmer.com
Length of Basin (ft)= 500 Measured at Principal Spillway Elevation
Width of Basin (ft)= 120 Measured at Principal Spillway Elevation
Desired Length to Width Ratio( :1)= 3
Actual Length to Width Ratio (:1)= 4.2 O.K.
SHEET
6/8
JOB#
WILSCN-20-1
DATE
10/12/2021
COMPUTED By
SWH
CHECKED By
WMB
SMITNGARONERINC Basin 1 SEDBASIN-GENERAL-westside C&DLFNre 2

DocuSign Envelope ID: F45A7F90-6A55-4F1A-89A4-806E1A91C808
PROJECT Westside C&D Landfill -Area 2 SHEET
7/8
JOB#
WILSCN-20-1
SUBJECT Sediment Basin Analysis DATE
10/12/2021
COMPUTED BY
SWH
CHECKED BY
WMB
ROUTE DESIGN STORM, Use HydroCAD or Other Method.
Design Parameters,
Design Storm: 25-Yr, 24-Hr
Design Storm Rainfall (in)= 6.79
Rainfall Distribution: Type II
Runoff Method: SCSTR-20
Results:
Maximum Pod Elevation = 96.3
Surface Area at Maximum Pool(ff')= 51,936
Peak Discharge (ofs)= 8.9
Check Bottling Efficiency:
Particle Data
Diam.(microns)=
40
Specific Gravity=
2.65
Settling Value. (ft/s)=
0.004140
Reynolds No.( 0.5) =
0.044284 O.K.
Efficiency Data,
Desired Efficiency( )=
80
No. of Effective Calls =
1
Settling Efficiency( )=
96.0 O.K.
Type of Riser:
Concrete -Rectangular
Top of Riser Base Elevation (ft) =
92.0
El ev. of Pr inci pal Spi l lway(ft)=
96.0
Riser Top Elevation (ft)=
97.0
Riser Height (ft) =
5.0
Outlets:
Outlet No. 1 (for Dewatering Dry Storage):
Si e: 6.0 Diam. For Skimmer From Above - Dewatering of Dry Storage
Invert Elevation: 92.1 May Vary For Multiple Holes
Outlet No. 2 (Principal Spillway):
Si e: 4.0 Wide x 1.0 H Weir (x4)
Invert Elevation: 96.0
Concrete Riser Wall Thickness (in)=
6.0
Riser Inside Length (ft)=
5.0
Poser Inside Wdth (ft)=
5.0
Approx.Fact. Concrete Riser Interior Volume (cf)=
100(Top of Baseto Principal Spillway)
Approx. Fact. Concrete Riser Vol. of Concrete (cf) =
44
Barrel Design:
Type of Barrel:
Concrete
Diameter(in)=
18
Inv. In Elevation (ft)=
92.0
Inv. Out Elevation (ft)- 90.0
Length (ft)=
130.0
Slope (ft/ft)=
0.015
SMITH 6ARONE INC Besin 1 SED BASIN-GENERAL-Mdestside C&D LF Area 2

DocuSign Envelope ID: F45A7F9O-6A55-4F1A-89A4-8O6E1A91C8O8
PROJECT Westside C&D Landfill -Area 2 SHEET
8/8
JOB#
WILSON-20-1
SUBJECT Sediment Basin Analysis DATE
10/12/2021
COMPUTED By
SWH
CHECKED BV
WMB
!4-77:=!'=ll l =
Factor of Safely = 1.25
F(unad usted)(I bs)= 7,800
0
Approx. Rect. Concrete Riser Buoyant W. (I bs) = 3,084 Factors in 80%of the Buoyant Weight of the Concrete Riser to Account for Out els.
0
0
Buoyant W. of Riser Top (I bs) = 1,-7 6' x 6' x 0.5' x Buoyant Wt. of Concrete (87.6 pcf)
Buoyant W. of Surrounding Soil Acting on Ext. Base (Ibs)= 1,440 3' Min. Depth x Outside Perimeter (24') x Base Protrusion (05) x Buoyant Wt. of Soil (40 pcf)
Slidi ng Resistance of Sur rounding Soil(I bs)= Im 0
F(ad usted)(I bs)= 1,700
Concrete Base*
Required Volume of Concrete (ft') 19.4
Length(ft)- 7.0
Wdth(ft )= 7.0
Thickness (ft)= 1.0 (includes Concrete Infill Inside of Box)
Actual Volume of Concrete Wt= 49.0 O.K.
Anti -Seepage Collar Calculations: (Alternatively- Design Filter Diaphragm)
Slope of Upstream Embankment( HAV)=
3
Slope of Outlet Pipe (ft/ft)=
0.015
L,(ft)=
37
Number of Collars:
2
Length of Each Collar (ft) =
4.0 From Design Chart Based on L, and No. of Col lars
Width of Each Collar (ft)=
4.0 From Design Chart Based on L, and No. of Collars
Collar Pro action, P(ft)=
1.25
Spacing of Subsequent Anti -Seep Collars (ft) =
18 =14P
Emergency Spillway Calculations:
Crest Elev. (ft)-
97.0
Required Freeboard (ft)=
1.0
Top of Berm Bev. (ft) =
98.0
Required Capacity (cfs) =
44.9 From HydroCAD
Driving Head (ft)=
0.5 Assumed
Weir Coefficient=
3.0
Length of Crest (ft)=
42.3 Determine by Weir Equation*
Design Crest Length (ft)=
44
- Length=2Oft minimum.
Basin No.: Basin 1
Elev. of Bottom of Basin (ft) =
92.0
6leanout Bev. (ft)=
94.2
Bev. of Wet Storage (Permanent Pool) (ft)=
NA
El— of Principal Spillway (ft) =
96.0 See Above for Poser and Other Design information.
Emergency Spillway Bev. (ft)=
97.0
Top of Berm Bev. (ft) =
98.0
Top of Berm Width (ft)=
10
Barrel Diameter (in)=
18
Barrel Slope( )=
1.5
SMITH GARON ER INC Basin 1 SED BASIN-GENERAL-westside C&D LF Area 2

DocuSign Envelope ID: F45A7F90-6A55-4F1A-89A4-806E1A91C808
TEL I WEB
14 N. Boylan Avenue, Raleigh, NC27603 919.828.0577 1 www.smithciardnerinc.com
PROJECT Westside C&D Landfill -Area 2 SHEET 1 OF 2
SUBJECT Outlet Protection Analysis JOB # WILSON-20-1
DATE 7/20/2020
COMPUTED BY SWH
CHECKED BY WMB
OBJECTIVE_ To design outlet protection for culverts and/or drainage channels based on the maximum flow from the
design storm. Rip rap aprons are applicable when the Froude Number (F,) is less than or equal to 2.5
(Debo and Reese). For higher Froude Numbers, rip rap outlet basins, baffled outlets, and/or other
methods are more appropriate.
REFERENCES: Debo, T.N., and Reese, A.J. (1995), Municipal Storm Water Management, Lewis Publishers, Boca Raton,
FL, Section 8.11 - pp. 289-290 Section 12.6 - pp. 523-526.
Federal Highway Administration (2000), Hydraulic Design of Energy Dissipators for Culverts and Channels,
Hydraulic Engineering Circular No. 14, FHWA EPD-86-110, Metric Ed., U.S. Dept. of Transportation,
Washington, D.C.
North Carolina Division of Land Resources (2013 Updates), North Carolina Erosion & Sediment Control
Planning & Design Manual, Raleigh, NC.
ANALYSIS: For each outlet, determine the Froude Number (Fr) based on the pipe Manning s number, diameter, slope,
and design discharge. Use the methods described in Section 8.11 of Debo and Reese. Select the method
of outlet protection, as appropriate, and perform design calculations.
Fain Rap Aprons:
If Fr 2.5, a rip rap apron may be used. The following design approach is based on Section 12.6 of Debo
and Reese and Section 8.06 of the NC Erosion & Sediment Control Planning and Design Manual:
1. Determine the tailwater condition and select the appropriate design chart.
2- Using the appropriate design chart, determine the d5o rip -rap si a and minimum apron length
(La) based on the maximum design flow (Q), flow depth (d), and/or velocity (v) (depending on
whether the pipe is flowing full or partiallyfull).
3. Using the same chart, determine apron dimensions.
4. Determine the maximum stone diameter: d.. =1.5 x d50
5. Determine the apron thickness:
Thickness = 1.5 x dma (No Filter Geotextile)
Thickness = 1.5 x d5o (With Filter Geotextile)
Other Methods:
If Fr 2.5, consider the use of a rip rap basin, baffled outlet, or other device. Design method according to
FHAguidelines using HY8-Energy program (or other documented source).
SMITH GARDNER, INC. OUTLET PROTECTION-Westside C&DArea 2

DocuSign Envelope ID: F45A7F90-6A55-4F1A-89A4-806E1A91C808
PROJECT Westside C&D Landfill -Area 2 SHEET
2/2
JOB#
WILSCN-20-1
SUBJECT Outlet Protection Analysis - Rip Rap Aprons (Circular Pipe) DATE
10/11/2021
COMPUTED BY
SWH
CHECKED BY
WMB
Rio Rap pA rom
Outlet
Basin SB-1
DI-1
Pipe Type:
Concrete
Concrete
Manning s Coefficient:
0.012
0.012
Diameter (Do) (in) =
18
36
Slope( )=
1.5
2.9
Design Discharge (cfs)=
15.8
65.0
Source of Discharge Data:
HydroCAD 25-Yr 24-Hr
HydroCAD 25-Yr 24-Hr
K =
0.353
0.165
0(degrees)=
265
185
Flow Depth (d) (in)=
15.1
18.8
Flow Area (ft2) =
1.6
3.7
Flow Velocity (v) (ft/sec) =
10.0
17.4
Froude Number =
1.57
2.45
Rip Rap Aprons Applicable
Yes
Yes
Tailwater Condition (Low or High) :
Low
Low
dso (ft) =
0.50
0.75
dmax(ft)=
0.75
1.13
Apron Thickness( ) (ft):
-----
-----
No Geotexti I e:
1.13
1.69
With Geotexti I e:
0.75
1.13
Apron Dimensions (ft):
-----
-----
Length (La) =
10
24
Width(W)=
11.5
27.0
Tailwater Conditions: Low: Tw 0.5Dc High: Tw 0.5Dc
Value from Chart.
SMITH GARGNER, INC. Rip Rap Aprons (Circular Pipe) OUTLET PROTECTION-Westside C&D Area 2

DocuSign Envelope ID: F45A7F90-6A55-4F1A-89A4-806E1A91C808
Appendices
3 0
Outlet IW = D0 + La
pipe i
diameter (Do)
La —W
iIwater < 0.5Do
ion `�,all�l,
rO'`Pp I
M11,
e`591
L. 1::_ llii:""I."' I I I I I 1 1 1 I LA I I I � I- II 'I'll•I I' 1.-ICI �I I I I �'I 1'1.!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. 12/93
8.06.3

DocuSign Envelope ID: F45A7F90-6A55-4F1A-89A4-806E1A91C808
This page intentionally left blank.

DocuSign Envelope ID: F45A7F90-6A55-4F1A-89A4-806E1A91C808
Appendix
Erosion and Sedimentation Control and Stormwater
Permits and Approvals
Erosion and Sedimentation Control Plan
Westside CAD Landfill — Area 2
Wilson, North Carolina

DocuSign Envelope ID: F45A7F90-6A55-4F1A-89A4-806E1A91C808
This page intentionally left blank.

DocuSign Envelope ID: F45A7F90-6A55-4F1A-89A4-806E1A91C808
IZOY CFtR
EUZA-DETH S. OFS�R
.Serrevarp
o&Y%C of
Fn "fur. mrn'r: f Qpriiii I -
June 27, 2022
LETTER OF APPROVAL
City of Wilson
ATTN: Denise Stinagle, County Manager
PO Box 1728
Wilson, NC 27894
RE: Project Name: Westside C&D Landfill -Area 2 Phase 1
Acres Approved: 19.97 Acres
Project ID: WILSO-2022-012
County: Wilson
City: Wilson
Address: NC 42 East
River Basin: Neuse
Stream Classification: Other
Submitted By: W. Michael Brinchek, PE, Smith+Gardner
Date Received by LQS: June 8, 2022
Plan Type: Revised
Dear Mr. Stingale,
This office has reviewed the subject erosion and sedimentation control plan. We find the
plan to be acceptable and hereby issue this Letter of Approval. The enclosed Certificate of
Approval must be posted at the job site. This plan shall expire three (3) years following the
date of approval, if no land disturbing activity has been undertaken, as is required by Title
15A NCAC 4B .0129.
As of April 1, 2019, all new construction activities are required to complete and submit an
electronic Notice of Intent (eNOI) form requesting a Certificate of Coverage (COC) under
the NCGO10000 Construction General Permit. After the form is reviewed and found to be
complete, you will receive a link with payment instructions for the $100 annual permit fee.
After the fee is processed, you will receive the COC via email. As the Financially
Responsible Party shown on the FRO form submitted for this project, you MUST obtain
the COC prior to commencement of any land disturbing activity. The eNOI form may be
accessed at deq.nc.gov/NCGO1. Please direct questions about the eNOI form to the
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DocuSign Envelope ID: F45A7F90-6A55-4F1A-89A4-806E1A91C808
Letter of Approval
City of Wilson
June 27, 2022
Page 2 of 3
Stormwater Program staff in the Raleigh central office. If the owner/operator of this
project changes in the future, the new responsible party must obtain a new COC.
Title 15A NCAC 4B .0118(a) and the NCGO1 permit require that the following
documentation be kept on file at the job site:
1. The approved E&SC plan as well as any approved deviation.
2. The NCGO1 permit and the COC, once it is received.
3. Records of inspections made during the previous 12 months.
Also, this letter gives the notice required by G.S. 113A-61.1(a) of our right of periodic
inspection to insure compliance with the approved plan.
North Carolina's Sedimentation Pollution Control Act is performance -oriented, requiring
protection of existing natural resources and adjoining properties. If, following the
commencement of this project, it is determined that the erosion and sedimentation control
plan is inadequate to meet the requirements of the Sedimentation Pollution Control Act of
1973 (North Carolina General Statute 113A-51 through 66), this office may require
revisions to the plan and implementation of the revisions to ensure compliance with the
Act.
Acceptance and approval of this plan is conditioned upon your compliance with Federal
and State water quality laws, regulations, and rules. In addition, local city or county
ordinances or rules may also apply to this land -disturbing activity. This approval does not
supersede any other permit or approval.
Please note that this approval is based in part on the accuracy of the information provided
in the Financial Responsibility Form, which you provided. You are requested to file an
amended form if there is any change in the information included on the form. In addition,
it would be helpful if you notify this office of the proposed starting date for this project.

DocuSign Envelope ID: F45A7F90-6A55-4F1A-89A4-806E1A91C808
Letter of Approval
City of Wilson
June 27, 2022
Page 3 of 3
Your cooperation is appreciated.
Sincerely,
Ivana Barham, PE
Assistant Regional Engineer
Land Quality Section
Enclosures: Certificate of Approval
NPDES NCGO1 Fact Sheet
cc: W. Michael Brinchek, PE, Smith+Gardner
Regional Office file

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DocuSign Envelope ID: F45A7F90-6A55-4F1A-89A4-806E1A91C808
CERTIFICATE OF PLAN APPROVAL
The posting of this certificate certifies that an erosion and sedimentation control plan has been
approved for this project by the North Carolina Department of Environmental Quality in
accordance with North Carolina General Statute 113A — 57 (4) and 113A — 54 (d) (4) and North
Carolina Administrative Code, Title 15A, Chapter 4B.0107 (c). This certificate must be posted
at the primary entrance of the job site before construction begins and until establishment of
permanent groundcover as required by North Carolina Administrative Code, Title 15A,
Chapter 4B.0127 (b).
Westside C &D Landfill Area 2 Phase 1: WILSO-2022-012
Project Name and Location
June 22, 2022
Date of Plan Approval
D_E�,
Certificate of Coverage Number
04taa, IV
Regional Engineer

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DocuSign Envelope ID: F45A7F90-6A55-4F1A-89A4-806E1A91C808
Nam.
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Envffon—tn! Qvailly
A. Project Information
NOTE: If you save a draft of this application, do not save it with uploaded attachments. This may cause problems
when you resume editing the draft and try to submit it. Remove all uploaded attachments before saving a draft.
Upload necessary documents only when you are ready to submit the eNO1.
Part A.
Proiect Location and Waterbodv Information
Are you submitting • No
an NOI that was Yes
rejected before?
la. Project Name* Westside C&D Landfill - Area 2 Phase 1
1 b. Specific Lot This field may be used to list specifc lot numbers.
Numbers
1 c. Parcel ID List all PINS associated with this project
Number(s) (PIN)* 3732-52-9078
2. County* Wilson
3. Highway or Street 2400 NC Hwy 42 East
Address* Street name only is acceptable if no address number assigned yet
4. City or Township* Wilson
5. State* NC
6. Zip Code* 27893
7. Latitude* Enter the latitude in decimal degrees
35.7210
8. Longitude* Enter the longitude in decimal degrees (MUST be negative)
-77.8620
If you do not know the latitude and longitude coordinates for this project, you can search the location on this map of North
Carolina. Look for the coordinates in the bottom left corner.
9. Date to Begin*
06/29/2022
Estimated Construction Project Start Date
10. Date to End*
06/30/2023
Estimated Construction Project End Date
11. SIC (Primary)*
Industrial (1541)
Standard Industrial Classification for Development

DocuSign Envelope ID: F45A7F90-6A55-4F1A-89A4-806E1A91C808
12. Acres to be IMPORTANT: Must match E&SC Plan Approval Letter or Grading Permit
disturbed* 19.97
(including off -site borrow and waste areas)
13. Total site area 700.00
(acres)*
14. Post -construction 2.10
impervious area (Estimated)
(acres) *
Below you must enter waterbody information for surface waters affected by this project. Please consult
DWR's Surface Water Classifications Map Viewer to find waterbody name and corresponding index number. Please enter
only immediate receiving waterbodies - not waters downstream of those unless the project extends there. You may enter
up to 3 waterbodies if needed.
15a. Receiving Buck Branch
Waterbody* Name of waterbody into which stormwater runoff will discharge
15b. Waterbody Index 27-86-11-6
No. * NC Waterbody Index Number
Stormwater ✓ No
discharges will flow Yes
to additional waters*
16a. Is this project • Yes
subject to the NC No, not subject to NC SPCA
Sediment Pollution
Control Act?*
Note: Stormwater discharges from construction activities associated with oil and gas exploration, production,
processing, treatment, or transmission facilities are eligible for the exemption from NPDES permit coverage except in
very limited instances. Do not proceed with this application before consulting this EPA fact sheet and verifying a permit
applies.

DocuSign Envelope ID: F45A7F90-6A55-4F1A-89A4-806E1A9lC808
B. Permittee Information
Part B. ^
Permittee Information - Legally Responsible Entity and Individual
Important: The person who signs the NOI Certification Form and signs the Certification in Section E of this application
form must be the same person as listed in THIS SECTION, or an authorized responsible individual within the same
organization. That person must be a responsible corporate officer who owns or operates the construction activity, such as
a president, secretary, treasurer, or vice president, or a manager that is authorized in accordance with Part IV, Section B,
Item (6) of the NCGO10000 General Permit. For more information on signatory requirements, see Part IV, Section B,
Item (6) of that permit.
1. Permittee* Legally Responsible Entity
Wilson County
If permittee is an individual, enter first and last name in this field. Otherwise, enter organization/business name.
Note: If the permittee is a business, the business must be registered with the NC Secretary of State. You can verify the
registration here. Permittee must be the same entity that is responsible for the land -disturbing activity as listed on the NC
SPCA Financial Responsibility/Ownership (FRO) Form.
2. First Name* Denise
3. Last Name* Stinagle
3b. Title* County Manager
4. Permitee E-mail [e-mail]
Address*
5. Permittee 252-399-2804
Telephone No.*
6. Permittee Mailing Street Address
Address* PO Box 1728
Address Line 2
City
State / Province / Region
Wilson
NC
Postal / Zip Code
Country
27894
Wilson
Check box if the Yes
street address the
same as mailing
address
7. Permittee Street
Street Address
Address*
2201 Miller Road South
Address Line 2
City
State / Province / Region
Wilson
NC
Postal / Zip Code
Country
27893-6860
us
8. Type of
Ownership is only individual if an individual is named in 13.1. above.
Ownership*
Government - County

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C. Site Contact information
2. Primary Site Davis
Contact - Last Name*
3. Title Director of Solid Waste Services
4. Site Contact E-mail [e-mail]
Address* This person will be copied on all correspondence.
5. Site Contact 252-399-2823
Telephone No.*
6. Organization Name
7. Site Contact
Street Address
Mailing Address*
PO Box 1728
Address Line 2
City
State / Province / Region
Wilson
NC
Postal / Zip Code
Country
27894
Wilson
8. Consultant Name
(optional)
Mike Brinchek
First and Last name
9. Consultant E-mail
[e-mail]
This person will be copied on all correspondence.
10. Consultant
919-815-0813
Telephone No.
Verify billing contact information and revise if necessary.
11. Billing E-mail*
(For Annual Fee correspondence)
[e-mail]
Default is legally responsible person e-mail
12. Billing
(For Annual Fee correspondence)
Telephone*
252-399-2804
Default is legally responsible person telephone

DocuSign Envelope ID: F45A7F90-6A55-4F1A-89A4-806E1A91C808
D. E&SC Plan
Part D.
Erosion & Sediment Control (E&SC) Plan Approval Information
1. Date E&SC Plan 06/27/2022
Approved *
2. E&SC Plan Project WILSO-2022-012
Number/ID * Assigned by agency or local program
3. E&SC Plan State DEQ Office
Approved by* Local Program
4. State DEQ Office* Raleigh Regional Office (RRO)
Documentation of E&SC Plan approval and the signed Notice of Intent (NOI) Certification Form is required for a
complete application. Please also upload a site map showing the overall extent of the project (for linear projects, can
include the beginning point and end point coordinates in the "Notes" box below).
5. E&SC Plan Approval documentation only! DO NOT upload entire set(s) of E&SC Plans
Approval letter or Letter of Approval.pdf 135.04KB
Grading Permit* Must be PDF format
6. Signed FRO* Financial Responsibility/Ownership Form
Signed FRO Form.pdf 1.17MB
Must be PDF format
7. Site Location Map* Must be PDF format (limit 20 MB)
Site Location Map.pdf 625.88KB
Please do not upload entire set of E&SC plans.
8. Notes (Optional) Provide any additional information that might help the reviewer better understand how uploaded documents
support the application. Include additional waterbodies if necessary.
9. NOI Certification NCG01.pdf 672.95KB
Form * Must be PDF format
YOU MUST MAIL THE ORIGINAL SIGNED NOI CERTIFICATION FORM (click on this link) to The Stormwater Program
at the address on the form for the application to fulfill federal application requirements. The Certification Form must be
signed by the person listed in Section B (Permittee Information) or by an authorized responsible person within the same
organization. NOTE: The person who signs the paper form must be the same person to electronically certify and
sign the eNOI.
This is an Express • No
Review Project* Yes

DocuSign Envelope ID: F45A7F90-6A55-4F1A-89A4-806E1A91C808
E. Certification
North Carolina General Statute 143-215.6113 (i) provides that:
Any person who knowingly makes any false statement, representation, or certification in any application, record, report, plan, or other document
filed or required to be maintained under this Article or a rule implementing this Article; or who knowingly makes a false statement of a material
fact in a rulemaking proceeding or contested case under this Article; or who falsifies, tampers with, or knowingly renders inaccurate any recording
or monitoring device or method required to be operated or maintained under this Article or rules of the Commission implementing this Article shall
be guilty of a Class 2 misdemeanor which may include a fine not to exceed ten thousand dollars ($10,000).
Under penalty of law, I certify that:
* ✓ I am the person responsible for the construction activities of this project, for satisfying
the requirements of this permit, and for any civil or criminal penalties incurred due to
violations of this permit.
* ✓ The information submitted in this NOI is, to the best of my knowledge and belief, true,
accurate, and complete based on my inquiry of the person or persons who manage the
system, or those persons directly responsible for gathering the information.
* ✓ I will abide by all conditions of the NCG010000 General Permit and the approved
Erosion and Sediment Control Plan.
* + I hereby request coverage under the NCG010000 General Permit and understand that
coverage under this permit will constitute the permit requirements for the discharge(s)
and is enforceable in the same manner as an individual permit.
Specify if you are:* • The Legally Responsible Person named on this Notice of Intent
Authorized Responsible Person' (signing on behalf of Legally Responsible Person
named in Part B)
Important: The person who electronically signs this Certification above must be the same person who signs the NOI
Certification Form. If that person is signing on behalf of the Permittee, that individual must be an authorized responsible
person within the same organization as the Permittee.
*An authorized individual is a responsible corporate officer who owns or operates the construction activity, such as a
president, secretary, treasurer, or vice president, or a manager that is authorized in accordance with Part IV, Section B,
Item (6) of the NCG010000 General Permit. For more information on signatory requirements, see Part IV, Section B,
Item (6) of that permit.
Signature*
Type Name* Denise Stinagle
Title* County Manager
Organization * Legally Responsible Entity
Wilson County
Date * 06/29/2022

DocuSign Envelope ID: F45A7F90-6A55-4F1A-89A4-806E1A9lC808
NCGO1 Notice of Intent (NOI) Certification Form
Directions:
Print this form, complete, scan and upload to the electronic NOI.
Then, mail the original form to the NC DEMLR Stormwater Program (with $100 check if paying by check) at:
Division of Energy, Mineral & Land Resources Stormwater Program
512 N. Salisbury Street, 6th Floor (Office 640K)
1612 Mail Service Center
Raleigh, NC 27699-1612
DO NOT MAIL THIS FORM OR PAYMENT UNTIL YOUR APPLICATION HAS BEEN ACCEPTED AS COMPLETE.
THE FORM YOU MAIL MUST BE COMPLETED WITH AN ORIGINAL SIGNATURE (NOT DIGITAL) [40 CFR 122.22]
Per NC General Statute 143-215.6B (i), any person who knowingly makes any false statement, representation, or
certification in any application, record, report, plan, or other document filed or required to be maintained under this
Article or a rule implementing this Article ... shall be guilty of a Class 2 misdemeanor which may include a fine not to
exceed ten thousand dollars ($10,000).
Under penalty of law, I certify that (check all boxes to indicate your agreement):
0 1 am the person responsible for the construction activities of this project, for satisfying the requirements of this
permit, and for any civil or criminal penalties incurred due to violations of this permit.
0 The information submitted in this NOI is, to the best of my knowledge and belief, true, accurate, and complete
based on my inquiry of the person or persons who manage the system, or those persons directly responsible for
gathering the information.
0 I will abide by all conditions of the NCG010000 General Permit and the approved Erosion and Sediment Control
Plan.
0 If the approved Erosion and Sediment Control Plan is not compliant with Part II (Stormwater Pollution
Prevention Plan) of the NCGO10000 General Permit, I will nonetheless ensure that all conditions of Part II of the
permit are met on the project at all times.
0 I hereby request coverage under the NCG010000 General Permit and understand that coverage under this
permit will constitute the permit requirements for the discharge(s) and is enforceable in the same manner as an
individual permit.
ct Name (must match Ala): Westside C&D Landfill -Area 2 Phase 1
c Lot Numbers (must match Alb);
Permittee (must match B1): Wilson County
Legally Responsible Person (must match B2 & B3): Denise Stinagle
Title of Legally Responsible Person (must match B3b): County Manager
Name & Title of Signed if Authorized individual
Differs from Legally Responsible Person:
Phone Number: 252.399.2804
6/29/22
Signature o g 11y R onsible Person or Authorized Individual Date
* IMPORTANT NOTE: This form must be signed by a responsible corporate officer that owns or operates the construction activity,
such as a president, secretary, treasurer, or vice president or a manager that is authorized in accordance with Part IV, Section B,
Item (6) of the NCG010000 permit.

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DocuSign Envelope ID: F45A7F90-6A55-4F1A-89A4-806E1A91C808
Mike Brinchek
From: [e-mail]
Sent: Wednesday, June 29, 2022 9:57 AM
To: [e-mail]
Cc: [e-mail]; [e-mail]; [e-mail];
[e-mail]; [e-mail]
Subject: Construction Stormwater eNO1 Status - Payment Instructions
Dear Construction Stormwater Permit Applicant:
We have reviewed the eNO1 that you submitted for Westside C&D Landfill - Area 2 Phase 1 submitted on 6/29/2022 and
found it to be complete.
Your Certificate of Coverage (COC) number: NCC222395
Project Name: Westside C&D Landfill - Area 2 Phase 1
Permittee Name: Wilson County
Legally Responsible Person: Denise Stinagle
This e-mail serves as the invoice for the initial annual permit fee.
Application Invoice No. NCC222395-2022
Annual Permit Fee: $100
Invoice Date: 6/29/2022
Due Date: 7/29/2022
After we receive payment of the $100 annual permit fee, we will e-mail you the COC for this project. Failure to pay the
annual fee in 30 days will result in your application being rejected, and you will need to re -apply for a new COC.
You have two options for paying the $100 fee:
1. Electronic payment by debit/credit card is preferred. To access the ePayment website, go to https://deq.nc.gov/sw-
epayments
You will need to enter the COC number above (NCC222395). If you select eCheck, there is no convenience fee. The
convenience fee for a credit card is 2.65%, and the convenience fee for debit card is $3.95.
2. Mail a $100 check made payable to "DEMLR Stormwater Program." After we receive the check in the Raleigh Central
Office, it will take 1-2 business days for us to e-mail your COC. A $25.00 processing fee will be charged for a returned
check in accordance with NC General Statute 25-3-512.
No matter which method of payment you choose, you must mail the original signed NOI Certification Form to:
DEMLR Stormwater Program
512 N. Salisbury Street, 640K
1612 Mail Service Center
Raleigh, NC 27699-1612
If you have any questions, contact the Stormwater Program at [phone] or by email at [e-mail].

DocuSign Envelope ID: F45A7F90-6A55-4F1A-89A4-806E1A91C808
The NC DEMLR Stormwater Program
512 N. Salisbury Street, Archdale Building 6th Floor (640K), 1612 Mail Service Center, Raleigh, NC 27699-1612
This email was automatically generated by Laserfiche. Please do not respond to this email address, as responses are not
monitored.