20081213 Ver 2_More Info Received_20081125

??? Kimley-Horn
and Associates, Inc.
Transmittal
Suite 300
4651 Charlotte Park Drive
Charlotte, North Carolina
28217
TEL [phone]
FAX [phone]
Date: November 24, 2008 Job Number: 018253026
Project Name: South Tract City Blvd Development Stormwater Management Plans
To: Joseph Gyamfi
Division of Water Quality
2321 Crabtree Blvd, Suite 250 D
Raleigh, NC 27604 NQ? ?+
919-715-3473N
We are sending these by
? U.S. Mail
? Other:
We are sending you
N Attached
? Shop Drawings
? Other:
EY-P CA-(x1-13 V2
N FedEx ? Hand Deliver

Under separate cover via the following items:
N Prints/Plans ? Samples Specifications []Change Orders
Copies Date No. Description
2 11/24/08 1 Revised South Tract City Blvd Stormwater Management Plans
2 11/24/08 2 Revised South Tract City Blvd Stormwater Management Calculations
2 11/24/08 3 Page 4 of Stormwater Application with Initials

These are transmitted as checked below:
N For your use ? Approved as submitted Resubmit ? Copies for approval
As requested ? Approved as noted r-1 Submit ? Copies for distribution
N For review and comment ? Returned for corrections ? Return ? Corrected prints
Copy to:
Signed Beverly Rosenbloom, E.I.
Page 1
¦
Revised Stormwater Management Calculations
South Tract
City Boulevard Development
Prepared for:
Crescent Resources, LLC
400 S. Tryon Street, Suite 1300
Charlotte, North Carolina 28202
© Kimley-Hom and Associates, Inc. 2008
P1R@RPwR5
NO V 2.5 2008
DENk As, UUr4t 1 Y
? ? ? Kimley-Horn WETLAN s% ORMWAIER BWWCH
and Associates, Inc.
IDS - 1 01 1?) u a.
SOUTH TRACT CITY BOULEVARD DEVELOPMENT
CHARLOTTE, NORTH CAROLINA
REVISED STORMWATER MANAGEMENT CALCULATIONS
Prepared for:
Crescent Resources, LLC
400 S. Tryon Street, Suite 1300
Charlotte, North Carolina 28202
Prepared by:
Kimley-Horn and Associates, Inc.
4651 Charlotte Park Drive, Suite 300
Charlotte, North Carolina 28217
NOVEMBER 2008
KRA Ref: 018253026
ess/
TABLE OF CONTENTS
OVERVIEW
SITE MAPS
SITE VICINITY MAP
SCS SOIL SURVEY
FEMA FIRM PANEL
WATERSHED MAPS
PRE-DEVELOPMENT WATERSHED MAP
POST-DEVELOPMENT WATERSHED MAP
WATER QUALITY
WET POND CALCULATIONS
ANTI-FLOTATION DEVICE CALCULATIONS
VOLUME AND SURFACE AREA TABLES
WET DETENTION BASIN SUPPLEMENT FORMS
WATER QUANTITY
CURVE NUMBER CALCULATIONS
TIME OF CONCENTRATION CALCULATIONS
HYDROCAD HYDROLOGY REPORT
STORMWATER MANAGEMENT CALCULATIONS i
South Tract city Boulevard Development, Charlotte, NC
OVERVIEW
' Background
This report contains the approach and results of a stormwater analysis conducted for the South
Tract City Boulevard Development. The 41-acre project site is located in the south east quadrant
of the interchange of Interstate 85 and City Boulevard in the City of Charlotte (see vicinity map).
The site has been mass graded per City of Charlotte permit number GRS-2007223.
' Existing Conditions
The existing on-site conditions (before mass grading) consisted of woods and meadow therefore
this ground cover was used in the analysis. The site topography varies from elevation 770 ft to
elevation 720 ft. Site runoff discharges into an existing stream in the middle portion of the site.
This stream drains to a culvert under City Blvd.
Floodplain/Floodway
The proposed site does not lie within a 100-year floodway boundary as determined by FIRM
Panel # 3717900070C.
Water Quality
Water quality treatment by means of permanent Best Management Practices (BMP's) will be
provided using two wet ponds as treatment. The ponds are designed to treat the first inch of
runoff per the Stormwater Model Ordinance for North Carolina and will draw down over a
period of two to five days. Wet Detention Basin 1 and Wet Detention Basin 2 have been
designed to provide a minimum 90% average annual removal of Total Suspended Solids (TSS).
Water Quantity
The proposed wet detention ponds have been designed to address the water quantity
requirements to match pre- and post-development peak runoff rates for the 1-year, 24-hour storm
events. (These ponds will also control the peak runoff rates for the 10- and 25-year, 6-hour storm
events per the City of Charlotte rezoning notes on Petition 2006-155. However, these water
quantity requirements will be reviewed by the City of Charlotte when the site develops.) The
100-year, 24-hour storm event was checked for 6" of freeboard at the top of bank.
Results
Pre-development
1-yr, 24-hr storm Post-development
1-yr, 24-hr storm
DA-1 2.63 cfs 1.51 cfs
DA-2 1.57 cfs 1.51 cfs
STORMWA TER MANAGEMENT CALCULATIONS
South Tract City Boulevard Development, Charlotte, NC
1
1
1
1
1
Conclusion
The proposed wet detention basins were designed using methods prescribed by the
aforementioned resources. HydroCAD software was utilized to evaluate the pre-development
and post-development flow rates. HydroCAD utilizes TR-55 methods of calculating times of
concentration (based on sheet, shallow concentrated, and channelized flows) and SCS curve
number method of generating hydrographs (results are provided in Appendix C). Based on the
analyses provided herein, the proposed system will be adequate to address the stormwater
requirements of the North Carolina Department of Environment and Natural Resources, Division
of Water Quality.
31 U.KMWA11:K MANAGEMENT CALCULATIONS
South Tract City Boulevard Development, Charlotte, NC
SITE MAPS
STORMWA TER MANAGEMENT CALCULATIONS
South Tract City Boulevard Development, Charlotte, North Carolina
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PRE-DEVELOPMENT
WATERSHED MAP
STORMWATER MANAGEMENT CALCULATIONS
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STORMWATER MANAGEMENT CALCULATIONS
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WET POND CALCULATIONS
STORMWA TER MANAGEMENT CALCULATIONS
' South Tract City Boulevard Development, Charlotte, North Carolina
PP- Kimley-Horn
and Associates, Inc.
WET DETENTION BASIN
Project Information
Project Name: Belgate - Southern Tract
KHA Project #: 018253026
Designed by: BRR Date: 1018/2008
Revised by: BRR Date: 10/27/2008
Revised by: BRR Date: 11/14/2008
Site Information
Sub Area Location: Drainage Area 1
Drainage Area (DA) = 7.15 Acres
Impervious Area (IA) = 6.43 Acres
Percent Impervious (1) = 89.9 %
Required Surface Area
Permanent Pool Depth: 4 ft
SA/DA = 4 (90% TSS Removal via Pond)
Min Req'd Surface Area = 12458 sf (at Permanent Pool)
Required Storage Volume:
Design Storm = 1 inch (Project Does Not Drain to SA waters)
Determine Rv Value = 0.05 +. 009 (1) = 0.86 inrn
Storage Volume Required = 22305 cf (above Permanent Pool)
Elevations Area (s.f.)
Bank Elevation = 732.00 ft
Top of Pond Elevation = 732.00 ft
Temporary Pool Elevation = 727.70 ft 19,373
Permanent Pool Elevation = 726.00 ft 14,257
Shelf Beginning Elevation = 726.50 ft
Forebay Weir = 728.00 ft
Shelf Ending Elevation = 725.50 ft
Sediment Cleanout Elevation = 718.00 ft
Bottom Elevation = 717.00 ft
Wet Basin Areas/Volumes (Elevation = 727.70)
Area @ Top of Temporary Pool = 19373 sf (Elevation = 726.00)
Area @ Top of Permanent Pool = 14257 sf
Volume of Temporary Storage = 28586 cf
Side Slopes of Pond = 3 : 1
Side Slopes of Shelf = 1 0 : 1
Side Slopes of Pond (below shelf) = 3 : 1
Yes ( 14257 > 12458) sf
Is Permanent Pool Surface Area Sufficient (yes/no)?
Volume of Storage Provided 28586 cf
Total Volume Sufficient (yes/no)? Yes
Orifice Size = 2.30 inches
r
i
WET DETENTION BASIN
Project Information
Project Name: Belgate - Southern Tract
KHA Project #: 018253026
Designed by: BRR Date:
Revised by: Date:
Revised by: BRR Date:
Site Information
4/1/2008
11/14/2008
Sub Area Location: Drainage Area 1
Drainage Area (DA) = 7.15 Acres
Impervious Area (IA) = 6.48 Acres
Percent Impervious (1) = 90.6 % (Drainage Area)
Orifice Sizing
Q2 Days = 0.1654 cfs
Qs Days = 0.0662 cfs
Orifice Size = 2.30 in
Q orifice = 0.102 cfs
Drawdown Time = 3.3 days
less than 5 days (yes/no) ? yes
greater than 2 days (yes/no) ? yes
(Flowrate required for a 2 day drawdown)
(Flowrate required for a 5 day drawdown)
(Diameter)
Orifice Equation: Q=cAgV(2gh) Q2 < Q < Q5
c = 0.6
A9= Area of Pipe = Tr/4D2
g = gravity = 32.2 ft/s2
h = orifice head = 1/3 (TPE-PPE-1/2D)
TPE = Temporary Pool Elevation
PPE = Permanent Pool Elevation
D = Diameter
1
1
1
1
1
1
1
1
1
1
1
1
PP-Z" Kimley-Horn
I , and Associates, Inc.
WET DETENTION BASIN
Project Information
Project Name: Belgate - Southern Tract
KHA Project #: 018253026
Designed by: BRR Date: 10/8/2008
Revised by: BRR Date: 10/19/2008
Revised by: BRR Date: 11/14/2008
Site Information
Sub Area Location: Drainage Area 2
Drainage Area (DA) = 24.40 Acres
Impervious Area (IA) = 18.30 Acres
Percent Impervious (1) = 75.0 %
Required Surface Area
Permanent Pool Depth: 4.35 ft
SA/DA = 3.375 (90% TSS Removal via Pond)
Min Req'd Surface Area = 35872 sf (at Permanent Pool)
Required Storage Volume:
Design Storm = 1 inch (Project Does Not Drain to SA waters)
Determine Rv Value = 0.05 +. 009 (1) = 0.73 in/in
Storage Volume Required = 64215 cf (above Permanent Pool)
Elevations Area (s.f.)
Bank Elevation = 725.00 ft
Top of Pond Elevation = 725.00 ft
Temporary Pool Elevation = 720.60 ft 46,100
Permanent Pool Elevation = 719.00 ft 38,235
Shelf Beginning Elevation = 719.50 ft
Forebay Weir = 722.00 ft
Shelf Ending Elevation = 718.50 ft
Sediment Cleanout Elevation = 712.00 ft
Bottom Elevation = 711.00 ft
Wet Basin Areas/Volumes
Area @ Top of Temporary Pool = 46100 sf (Elevation = 720.60)
Area @ Top of Permanent Pool = 38235 sf (Elevation = 719.00)
Volume of Temporary Storage = 67468 cf
Side Slopes of Pond = 3 : 1
Side Slopes of Shelf = 1 0 : 1
Side Slopes of Pond (below shelf) = 3 : 1
Is Permanent Pool Surface Area Sufficient (yes/no)? Yes ( 38235 > 35872) sf
Volume of Storage Provided 67468 cf
Total Volume Sufficient (yes/no)? Yes
Orifice Size = 2.90 inches
WET DETENTION BASIN
Project Information
Project Name: Belgate - Southern Tract
KHA Project #: 018253026
Designed by: BRR Date:
Revised by: BRR Date:
Revised by: BRR Date:
Site Information
Sub Area Location: Drainage Area 2
Drainage Area (DA) = 24.40 Acres
Impervious Area (IA) = 18.30 Acres
Percent Impervious (1) = 75.0 % (Drainage Area)
Orifice Sizing
11/14/2008
Q2 Days= 0.3904 cfs (Flowrate required for a 2 day drawdown)
Qs Days= 0.1562 cfs (Flowrate required for a 5 day drawdown)
Orifice Size = 2.90 in (Diameter)
Q office = 0.155 cfs
Drawdown Time = 5.0 days
less than 5 days (yes/no) ? yes
greater than 2 days (yes/no) ? yes
Orifice Equation: Q=CAgV(2gh) Q2 < Q < Q5
c = 0.6
A9= Area of Pipe = n14D2
g = gravity = 32.2 ft/s2
h = orifice head = 1/3 (TPE-PPE-1/2D)
TPE = Temporary Pool Elevation
PPE = Permanent Pool Elevation
D = Diameter
10/19/2008
11/3/2008
ANTI-FLOTATION DEVICE CALCULATIONS
STORMWA TER MANAGEMENT CALCULATIONS
South Tract City Boulevard Development, Charlotte, North Carolina
1
1
1
1
1
1
1
1
1
1
P-.Mn IGdey H..
\' and ASmcM, NC.
NCDENR ANTIFLOATATION DEVICE DESIGN CALCULATIONS
(per NCDENR Manual)
Project Information
Project Name: Belgate - Southern Tract
KHA Project #: 018253026
Designed by: BRR Date: 1113/2008
Revised by: Date:
Revised by: Date:
Revised by: Date:
Pond 7
Drainage Area Information:
Drainage Area (ac) = 7.15
Flow (Q?) (cfs) = 12.8
Storage Dimensions:
Basin Side Slopes I X : 1 ) = 3.0 (3:1 max side slopes)
Storage Depth "R" (ft) = 9.0
Elev (ft) Area (SF) Cumulative Volume (CF)
Top of Basin Elevation 732.00 27.972
730.00 23.807 124,239
Temporary Pool Elevation 727.70 16.459 77,934
Permanent Pool Elevation 725.00 11,541 54.134
723.00 7.735 25.220
720.00 3,846 7.848
Bottom of Basin Elevation 717.00 1,386 0
Control Structure Length (in) = 48
Control Structure Width (in) = 36
Riser Area (sf) = 12.00 (Check riser geometry vs. area equation)
Volume of Water Displaced (cf) = 108.0
Weight of Water Displaced (Ib) = 6,739
Min. Required Weight of Anchor Block (lb) = 7,413 (1.1 factor of safety)
Anchor Size:
Width (It) = 4.4
Length (If) = 5.0
Height (If) = 4.00
Weight of Anchor (lb) = 7,709 O. K. > Minimum Required Weight
Sizing of Emergency Spillway:
0. (cfs) = 12.8
Q.0'". (cfs) = 12.8 (Riser ignored)
Water Depth Over Spillway (ft) = 0.5
Spillway Length (ft) = 15.0 (10 ft minimum spillway length, Cw=2.7)
Spillway Crest Elevation (ft) = 730.5 (1 ft min. above sediment storage depth)
Freeboard (ft) = 1.04 (1 ft minimum)
Page 1 of 1
Z Bntl ASSOCWGS,IK.
NCDENR ANTIFLOATATION DEVICE DESIGN CALCULATIONS
(per NCDENR Manual)
Project Information
Project Name: Belgate - Southern Tract
KHA Project #: 018253026
Designed by: BRR Date: 11132008
Revised by: Date:
Revised by: Date:
Revised by: Date:
Pond 2
Drainage Area Information:
Drainage Area (ac) = 23.90
Flow (Q?) (cfs) = 167
Storage Dimensions:
Basin Side Slopes L : 1 ) = 3.0 (3:1 max side slopes)
Storage Depth "R" (ft) = 7.0
Elev (ft) Area (SF) Cumulative Volume (CF)
Top of Basin Elevation 725.00 60.143
723.00 53.616 332,340
Temporary Pool Elevation 720.70 39.312 225.473
Permanent Pool Elevation 719.00 31.750 165,071
716.00 22.055 84,363
714.00 17.794 44.514
Bottom of Basin Elevation 711.00 11.882 0
Control Structure Length (in) = 48
Control Structure Width (in) = 35
Riser Area (sf) = 12.00 (Check riser geometry vs. area equation)
Volume of Water Displaced (cf) = 96.0
Weight of Water Displaced (lb) = 5,990
Min. Required Weight of Anchor Block (lb) = 6,589 (1.1 factor of safety)
Anchor Size:
Width (If) = 41
Length (If) = 4.8
Height (If) = 4.00
Weight of Anchor (lb) = 6,896 O.K. > Minimum Required Weight
Sizing of Emergency Spillway:
0. (cfs) = 16.7
Qcrvi,,? (cfs) = 16.7 (Riser ignored)
Water Depth Over Spillway (ft) = 0.5
Spillway Length (ft) = 40.0 (10 It minimum spillway length, Cv=-2.7)
Spillway Crest Elevation (ft) = 7237 (1 It min. above sediment storage depth)
Freeboard (ft) = 1.01 (1 It minimum)
Page 1 of 1
VOLUME AND SURFACE AREA TABLES
STORMWATER MANAGEMENT CALCULATIONS
South Tract City Boulevard Development, Charlotte, North Carolina
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WET DETENTION BASIN
SUPPLEMENT FORMS
STORMWA TER MANAGEMENT CALCULATIONS
South Tract Ciry Boulevard Development, Charlotte, North Carolina
AM7114VAA
NCDENR
Permit N
(to be provided by DWQ)
oaoF WArF9pG
O T
STORMWATER MANAGEMENT PERMIT APPLICATION FORM
401 CERTIFICATION APPLICATION FORM
WET DETENTION BASIN SUPPLEMENT
This form must be filled out, printed and submitted.
The Required Items Checklist (Part Ill) must be printed, filled out and submitted along with all of the required information.
I. PROJECT INFORMATION '
Project name Belgate Southern Tract
Contact person Beverly Rosenbloom, El
Phone number 704-319-7699
Date 11/24/2008
Drainage area number 1
11. DESIGN INFORMATION
Site Characteristics
Drainage area 311,454.00 ftz
Impervious area 280,090.80 ft2
% impervious 89.93 %
Design rainfall depth 1.00 in
Storage Volume: Non-SR Waters
Minimum volume required 22,305.00 ft3
Volume provided 28,586.00 ft3
Storage Volume: SR Waters
1-yr, 24-hr runoff depth in
Pre-development 1-yr, 24-hr runoff ft3
Post-development 1-yr, 24-hr runoff ft3
Minimum volume required ft3
Volume provided ft3
Peak Flow Calculations
1-yr, 24-hr rainfall depth 2.58 in
Rational C, pre-development 0.28 (unitless)
Rational C, post-development 0.88 (unitless)
Rainfall intensity: 1-yr, 24-hr storm 0.12 in/hr
Pre-development 1-yr, 24-hr peak flow 2.63 ft3/sec
Post-development 1-yr, 24-hr peak flow 9.25 ft3/sec
Pre/Post 1-yr, 24-hr peak flow control 6.62 ft3/sec
Basin Elevations
Basin bottom elevation 717.00 ft
Sediment cleanout elevation 718.00 ft
Bottom of shelf elevation 725.50 - ft
Permanent pool elevation 726.00 ft
SHWT elevation 712.00 ft
Top of shelf elevation 726.50 ft
Temporary pool elevation 727.70 ft
Form SW401-Wet Detention Basin-Rev.4 Parts I. & II. Design Summary, Page 1 of 2
Permit
(to be provided by DWQ)
Ill, DESIGN INFORMATION'
Volume and Surface Area Calculations
SA/DA ratio 4.00 (unitless)
Surface area at the bottom of shelf 8,955.00 ftz
Volume at the bottom of shelf 42,518.00 ft3
Permanent pool, surface area required 12,458.00 e
Permanent pool, surface area provided 14,257.00 e OK
Permanent pool volume 58,619.00 ft3
Average depth for SA/DA tables 4.11 ft OK
Surface area at the top of shelf 14,328.00 f 2
Volume at the top of shelf 54,109.00 ft3
Forebay volume 10,977.00 ft3
Forebay % of permanent pool volume 18.73 % OK
Temporary pool, surface area provided 19,373.00 f 2
Drawdown Calculations
Treatment volume drawdown time 3.30 days OK
Treatment volume discharge rate 0.10 ft3/S
Pre-development 1-yr, 24-hr discharge 2.63 ft3/s OK
Post-development 1-yr, 24-hr discharge 1.76 ft3/s OK
Additional Information
Diameter of orifice 2.3 in
Design TSS removal 90 %
Basin side slopes 3.00 :1 OK
Vegetated shelf slope 10.00 :1 OK
Vegetated shelf width 10.00 ft OK
Length of flowpath to width ratio 4.40 :1 OK
Length to width ratio 3.30 :1 OK
Trash rack for overflow & orifice? Y (Y or N) OK
Freeboard provided 2.25 ft OK
Vegetated filter provided? N (Y or N) Design must be based on 90% TSS removal
Recorded drainage easement provided? Y (Y or N) OK
Capures all runoff at ultimate build-out? Y (Y or N) OK
Drain mechanism for maintenance or emergencies 24-HR EMERGENCY PUMP
Form SW401-Wet Detention Basin-Rev.4 Parts I. & II. Design Summary, Page 2 of 2
' Permit No.
(to be provided by DWQ)
' III. REQUIRED ITEMS CHECKLIST
Please indicate the page or plan sheet numbers where the supporting documentation can be found. An incomplete submittal package will
result in a request for additional information. This will delay final review and approval of the project. Initial in the space provided to
indicate the following design requirements have been met. If the applicant has designated an agent, the agent may initial below. If a
requirement has not been met, attach justification.
Pagel Plan
Initials Sheet No.
F -C-3-
1 . Plans (1" - 50' or larger) of the entire site showing:
- Design at ultimate build-out,
- Off-site drainage (if applicable),
- Delineated drainage basins (include Rational C coefficient per basin),
- Basin dimensions,
- Pretreatment system,
- High flow bypass system,
- Maintenance access,
- Proposed drainage easement and public right of way (ROW),
- Overflow device, and
- Boundaries of drainage easement.
K C-4 2. Partial plan (1" = 30' or larger) and details for the wet detention basin showing:
- Outlet structure with trash rack or similar,
- Maintenance access,
- Permanent pool dimensions,
- Forebay and main pond with hardened emergency spillway,
- Basin cross-section,
- Vegetation specification for planting shelf, and
-Filter strip.
'
?KK C-7 3. Section view of the dry detention basin (1" = 20' or larger) showing:
- Side slopes, 3:1 or lower,
- Pretreatment and treatment areas, and
- Inlet and outlet structures.
_C-3 4. If the basin is used for sediment and erosion control during construction, clean out of the basin is specified
on the plans prior to use as a wet detention basin.
'
?3eC _C-4 5. A table of elevations, areas, incremental volumes & accumulated volumes for overall pond and for forebay,
to verify volume provided.
Attached 6. A construction sequence that shows how the wet detention basin will be protected from sediment until the
entire drainage area is stabilized.
13KC _Calc book- 7. The supporting calculations.
Attached-
- 8. A copy of the signed and notarized operation and maintenance (O&M) agreement.
-Attached- 9. A copy of the deed restrictions (if required).
-Attached- 10. A soils report that is based upon an actual field investigation, soil borings, and infiltration tests. County
soil maps are not an acceptable source of soils information.
I Form SW401-Wet Detention Basin-Rev.4 Part III. Required Items Checklist, Page 1 of 1
Permit No.
(to be provided by DWQ)
VfA
i NC©ENR
O?O? W AT??OG
O T
STORMWATER MANAGEMENT PERMIT APPLICATION FORM
401 CERTIFICATION APPLICATION FORM
WET DETENTION BASIN SUPPLEMENT
This form must be filled out, printed and submitted.
The Required Items Checklist (Part 111) must be printed, filled out and submitted along with all of the required information.
1. PROJECT INFORMATION _
Project name Belgate Southern Tract
Contact person Beverly Rosenbloom, El
Phone number 704-319-7699
Date 11/24/2008
Drainage area number 2
111. DESIGN INFORMATION
Site Characteristics
Drainage area 1,062,864.00 ft2
Impervious area 797,148.00 ft2
% impervious 75.00 %
Design rainfall depth 1.00 in
Storage Volume: Non-SR Waters
Minimum volume required 64,215.00 ft3
Volume provided 67,468.00 ft3
Storage Volume: SR Waters
1-yr, 24-hr runoff depth in
Pre-development 1-yr, 24-hr runoff ft3
Post-development 1-yr, 24-hr runoff ft3
Minimum volume required ft3
Volume provided ft3
Peak Flow Calculations
1-yr, 24-hr rainfall depth 2.58 in
Rational C, pre-development 0.28 _ (unitless)
Rational C, post-development 0.79 (unitless)
Rainfall intensity:1-yr, 24-hr storm 0.12 in/hr
Pre-development 1-yr, 24-hr peak flow 1.57 ft3/sec
Post-development 1-yr, 24-hr peak flow 24.36 ft3/sec
Pre/Post 1-yr, 24-hr peak flow control 22.79 ft3lsec
Basin Elevations
Basin bottom elevation 711.00 It
Sediment cleanout elevation 712.00 ft
Bottom of shelf elevation 718.50 ft
Permanent pool elevation 719.00 It
SHWT elevation 708.00 ft
Top of shelf elevation 719.50 ft
Temporary pool elevation 720.60 ft
Form SW401-Wet Detention Basin-Rev.4 Parts I. & If. Design Summary, Page 1 of 2
Permit No.
(to be provided by DWQ)
II. DESIGN INFORMATION
Volume and Surface Area Calculations
SAIDA ratio 3.38 (unitless)
Surface area at the bottom of shelf 27,740.00 f 2
Volume at the bottom of shelf 133,518.00 ft3
Permanent pool, surface area required 35,872.00 ftZ
Permanent pool, surface area provided 38,235.00 ft OK
Permanent pool volume 181,976.00 ft3
Average depth for SAIDA tables 4.76 ft OK
Surface area at the top of shelf 35,931.00 fe
Volume at the top of shelf 165,311.00 ft3
Forebay volume 33,586.00 ft3
Forebay % of permanent pool volume 18.46 % OK
Temporary pool, surface area provided 46,100.00 f{2
Drawdown Calculations
Treatment volume drawdown time 5.00 days OK
Treatment volume discharge rate 0.16 ftN
Pre-development 1-yr, 24-hr discharge 1.57 ft3IS OK
Post-development 1-yr, 24-hr discharge 1.51 ft3IS OK
Additional Information
Diameter of orifice 2,9 in
Design TSS removal 90 %
Basin side slopes 3.00 :1 OK
Vegetated shelf slope 10.00 :1 OK
Vegetated shelf width 10.00 ft OK
Length of flowpath to width ratio 4.10 :1 OK
Length to width ratio 3.20 :1 OK
Trash rack for overflow & orifice? Y (Y or N) OK
Freeboard provided 2.65 ft OK
Vegetated filter provided? N (Y or N) Design must be based on 90% TSS removal
Recorded drainage easement provided? Y (Y or N) OK
Capures all runoff at ultimate build-out? Y (Y or N) OK
Drain mechanism for maintenance or emergencies 24-HR EMERGENCY PUMP
Form SW401-Wet Detention Basin-Rev.4 Parts I. & 11. Design Summary, Page 2 of 2
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
Permit No
(to be provided by DWQ)
Ill. REQUIRED sITEMS CHECKLIST _
Please indicate the page or plan sheet numbers where the supporting documentation can be found. An incomplete submittal package will
result in a request for additional information. This will delay final review and approval of the project. Initial in the space provided to
indicate the following design requirements have been met. If the applicant has designated an agent, the agent may initial below. If a
requirement has not been met, attach justification.
Pagel Plan
Initials Sheet No.
C-3_ 1. Plans (1" - 50' or larger) of the entire site showing:
- Design at ultimate build-out,
- Off-site drainage (if applicable),
- Delineated drainage basins (include Rational C coefficient per basin),
- Basin dimensions,
- Pretreatment system,
- High flow bypass system,
- Maintenance access,
- Proposed drainage easement and public right of way (ROW),
- Overflow device, and
- Boundaries of drainage easement.
C-4 2. Partial plan (1" = 30' or larger) and details for the wet detention basin showing:
- Outlet structure with trash rack or similar,
- Maintenance access,
- Permanent pool dimensions,
- Forebay and main pond with hardened emergency spillway,
- Basin cross-section,
- Vegetation specification for planting shelf, and
- Filter strip.
S1IVK _C-7_ 3. Section view of the dry detention basin (1" = 20' or larger) showing:
- Side slopes, 3:1 or lower,
- Pretreatment and treatment areas, and
- Inlet and outlet structures.
9]tX C-3 4. If the basin is used for sediment and erosion control during construction, clean out of the basin is specified
on the plans prior to use as a wet detention basin.
J 't C-4 5. A table of elevations, areas, incremental volumes & accumulated volumes for overall pond and for forebay,
A,ftjApL I - to verify volume provided.
,6. A construction sequence that shows how the wet detention basin will be protected from sediment until the
entire drainage area is stabilized.
_Calc book- 7. The supporting calculations.
-Attached- 8. A copy of the signed and notarized operation and maintenance (0&M) agreement.
-Attached- 9. A copy of the deed restrictions (if required).
AO& -Attached- 10. A soils report that is based upon an actual field investigation, soil borings, and infiltration tests. County
soil maps are not an acceptable source of soils information.
Form SW401-Wet Detention Basin-Rev.4
Part III. Required Items Checklist, Page 1 of 1
CURVE NUMBER CALCULATIONS
STORMWA TER MANAGEMENT CALCULATIONS
South Tract City Boulevard Development, Charlotte, North Carolina
IIiI? Kimley-Hom
U? , and Associates, Inc.
Pre vs. Post Runoff Analysis
Composite Curve Number (CN)
Project Information
Project Name: Southern Tract
KHA Project #: 018253026
Designed by: BRR Date: 10/6/2008
Revised by: BRR Date: 11/14/2008
Revised by: Date:

Drainage Area
Name
Drainage
Location
Cover/Soil
Name (Type)

Cover Description*
Hydrologic Soil
Group

Curve # (CN)**

Area (ac)
Product of
CN x area omposite
Curve Number
(CN)
PRE-DEVELOPMENT

DA-1
OUTFALL 1 Mecklenburg,
Enon, Wilkes Woods
Good Condition C
70
5.04
353
70
Meadow
Good Condition B
71
5.04
358
71
10.08 711 70.5

DA-2
OUTFALL 1 Mecklenburg,
Enon, Wilkes Woods
Good Condition
C
70
2.95
207
70
Mecklenburg,
Enon, Wilkes Meadow
Good Condition
C
71
2.95
209
71

Cecil Meadow
Good Condition
B
58
10.69
620
58

Cecil Woods
Good Condition
B
55
10.69
588
55
27.28 1624 59.5
Total Pre-development Area = 37.36
POST DEVELOPMENT
DA-1 POND 1 Impervious 98 6.43 631 98
Mecklenburg,
Enon, Wilkes
Open Space - Good Condition
C
74 -
0.71
53 74
7.15 683.46 95.60 --

UND DA-1
OUTFALL 1 Mecklenburg,
Enon, Wilkes
Open Space - Good Condition
C 74
1.15
85
74
1.15 85.10 74.00
DA-2 POND 2 Impervious 98 15.40 1509 98
Mecklenburg,
Enon, Wilkes
Open Space - Good Condition
C
74
0.83
61
74
Cecil Open Space - Good Condition B 61 4.11 251 61
Roadway - Impervious 98 2.90 284 98
Mecklenburg,
Enon, Wilkes
Roadway - Open Space
C
74
1.06
78
74
Cecil Roadway - Open Space B 61 0.10 6 61
24.40 2190.07 89.76

UND DA-2 Mecklenburg,
OUTFALL 2 Enon, Wilkes
Open Space - Good Condition
C
74
2.96
219
74
Cecil Open Space - Good Condition B 61 2.97 181 61
] 1 5.93 400.21 67.49
Total Post-development Area = 38.63
* Cover Descriptions per TR-55 Manual
** From TR-55 Manual, Table 2-2 a & c
K:\CHL_LDEV\018253 Crescent\026 Belgate\Belgate Stormwater Management Plan\Calculations\Parcel J\Stormwater Calculations_2008-10-06.xls 1 of 1
TIME OF CONCENTRATION
CALCULATIONS
EROSION CONTROL CALCULATIONS
t New Towne Gardens, Union County, North Carolina
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HYDROCAD HYDROLOGY REPORT
EROSION CONTROL CALCULATIONS
New Towne Gardens, Union County, North Carolina
1
1
1
1
1
1
1
1
1
i
1
1
1
1
1S 2S 4S
Pre-dev DA-1 Post-d(-.v DA-1 Post-dev ND DA-1
v Z8P
3P
Pond 1 Outfall 1
5S 6S 8S
Pre-dev DA-2 Post-d v DA-2 Post-dev ND DA-2
7P 9P
Pond 2 Outfall 2
Subca Reach on [Link
Southem Tract SWMP Charlotte 24-hr 1-yr 24.00 hrs 1 yr - 24 hr Rainfall=2.58"
Prepared by Kimley-Horn and Associates, Inc. Printed 11/24/2008
HydroCAD® 8.50 s/n 005123 @2007 HydroCAD Software Solutions LLC Page 2
Time span=0.00-24.00 hrs, dt=0.05 hrs, 481 points
Runoff by SCS TR-20 method, UH=SCS
Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method
Subcatchment 1S: Pre-dev DA-1 Runoff Area= 10.080 ac 0.00% Impervious Runoff Depth>0.53"
Tc=25.2 min CN=71 Runoff=2.63 cfs 0.443 of
Subcatchment 2S: Post-dev DA-1 Runoff Area=7.150 ac 0.00% Impervious Runoff Depth>2.14"
Tc=5.0 min CN=96 Runoff=9.25 cfs 1.274 of
Subcatchment 4S: Post-dev UND DA -1 Runoff Area=1.150 ac 0.00% Impervious Runoff Depth>0.65"
Tc=5.0 min CN=74 Runoff=0.47 cfs 0.063 of
Subcatchment 5S: Pre-dev DA-2 Runoff Area=27.280 ac 0.00% Impervious Runoff Depth>0.19"
Tc=25.0 min CN=60 Runoff=1.57 cfs 0.441 of
Subcatchment 6S: Post-dev DA-2 Runoff Area=24.400 ac 0.00% Impervious Runoff Depth>1.52"
Tc=5.0 min CN=89 Runoff=24.36 cfs 3.098 of
Subcatchment 8S: Post-dev UND DA-2 Runoff Area=5.930 ac 0.00% Impervious Runoff Depth>0.39"
Tc=5.0 min CN=67 Runoff=1.27 cfs 0.193 of
Pond 3P: Pond 1 Peak EIev=728.03' Storage=35,851 cf Inflow=9.25 cfs 1.274 of
Outflow=1.40 cfs 0.569 of
Pond 7P: Pond 2 Peak EIev=721.69' Storage=120,244 cf Inflow=24.36 cfs 3.098 of
Outflow=0.35 cfs 0.338 of
Pond 8P: Outfall 1 Inflow=1.51 cfs 0.632 of
Primary=1.51 cfs 0.632 of
Pond 9P: Outfall 2 Inflow=1.51 cfs 0.530 of
Primary=1.51 cfs 0.530 of
Total Runoff Area = 75.990 ac Runoff Volume = 5.511 of Average Runoff Depth = 0.87" ,
100.00% Pervious= 75.990 ac 0.00% Impervious = 0.000 ac
' Southem Tract SWMP Charlotte 24-hr 1-yr 24.00 hrs 1 yr - 24 hr Rainfall=2.58"
Prepared by Kimley-Horn and Associates, Inc. Printed 11/24/2008
HydroCAD® 8.50 s/n 005123 @2007 HydroCAD Software Solutions LLC Paiae 3
Summary for Subcatchment 1S: Pre-dev DA-1
Runoff = 2.63 cfs @ 12.77 hrs, Volume= 0.443 af, Depth> 0.53"
Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs
Charlotte 24-hr 1-yr 24.00 hrs 1 yr - 24 hr Rainfall=2.58"
Area (ac) CN Description
10.080 71
10.080 Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
25.2 Direct Entry, From spreadsheet
I Subcatchment 1S: Pre-dev DA-1
Hydrograph
2.63 cfs
Charlotte 24-hr
1-yr 24.00 hrs 1 yr - 24 hr
2 Rainfall=2.58
Runoff Area=10.080 ac
4 Runoff Volume=0.443 of
LL Runoff Depth>0.53"
' Tc=25.2 min
CN=71
0 i r*W.--. i i'1 i i i i- i i i iT. i ..... i .. 1 i iTT^1'?*^T
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 151"6--17 18 19 20 21 22 23 24
Time (hours)
¦ Runoff
Southem Tract SWMP Charlotte 24-hr 1-yr 24.00 hrs 1 yr - 24 hr Rainfall=2.58"
Prepared by Kimley-Horn and Associates, Inc. Printed 11/24/2008
HydroCAM 8.50 s/n 005123 @2007 HydroCAD Software Solutions LLC Page 4
Summary for Subcatchment 2S: Post-dev DA-1
[49] Hint: Tc<2dt may require smaller dt
Runoff = 9.25 cfs @ 12.40 hrs, Volume= 1.274 af, Depth> 2.14"
Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs
Charlotte 24-hr 1-yr 24.00 hrs 1 yr - 24 hr Rainfall=2.58"
Area (ac) CN Description
7.150 96
7.150 Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
5.0 Direct Entry, From spreadsheet
Subcatchment 2S: Post-dev DA-1
Hydrograph
10
9.25 cfs
9 Charlotte 24-hr
8 1-yr 24.00 hrs 1 yr - 24 hr
Rainfall=2.58"
Runoff Area=7.150 ac
Runoff Volume=1.274 of
L 5 Runoff Depth>2.14"
4 Tc=5.0 min
3 CN=96
1
¦ Runoff
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
Time (hours)
Southem Tract SWMP Charlotte 24-hr 1-yr 24.00 hrs 1 yr - 24 hr Rainfall=2.58"
Prepared by Kimley-Horn and Associates, Inc. Printed 11/24/2008
HydroCAD® 8.50 s/n 005123 @2007 HydroCAD Software Solutions LLC Page 5
Summary for Subcatchment 4S: Post-dev UND DA-1
[49] Hint: Tc<2dt may require smaller dt
Runoff = 0.47 cfs @ 12.45 hrs, Volume= 0.063 af, Depth> 0.65"
Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs
Charlotte 24-hr 1-yr 24.00 hrs 1 yr - 24 hr Rainfall=2.58"
Area (ac) CN Description
1.150 74
1.150 Pervious Area
Tc Length Slope Velocity Capacity Description
_(min) (feet) (ft/ft) (ft/sec) (cfs)
5.0 Direct Entry,
Subcatchment 4S: Post-dev UND DA-1
Hydrograph
0.5 _ _ _ _ - _ ¦ Runoff
0.47 cfs
0.45- 1 Charlotte 24-hr
0.4 1-yr 24.00 hrs 1 yr 24 hr
Rainfall=2.58"
0.35 Runoff Area=1.150 ac
03 Runoff Volume=0.063 of
0 0.25 Runoff Depth>0.65"
0.2 Tc=5.0 min
0.15 CN=74
0.1-
0.05-
0--
7 1 2 3 4 5 6 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
Time (hours)
Southem Tract SWMP Charlotte 24-hr 1-yr 24.00 hrs 1 yr - 24 hr Rainfall=2.58"
Prepared by Kimley-Horn and Associates, Inc. Printed 11/24/2008
HydroCAD® 8.50 s/n 005123 @2007 HydroCAD Software Solutions LLC Page 6
Summary for Subcatchment 5S: Pre-dev DA-2
Runoff = 1.57 cfs @ 13.04 hrs, Volume= 0.441 af, Depth> 0.19"
Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs
Charlotte 24-hr 1-yr 24.00 hrs 1 yr - 24 hr Rainfall=2.58"
Area (ac) CN Description
27.280 60
27.280 Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
25.0 Direct Entry, From Spreadsheet
Subcatchment 5S: Pre-dev DA-2
Hydrograph
1.57 cfs
Charlotte 24-hr
1-yr 24.00 hrs 1 yr - 24 hr
Rainfall=2.58"
Runoff Area=27.280 ac
' Runoff Volume=0.441 of
Runoff Depth>0.19"
Tc=25.0 min
CN=60
¦ Runoff
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
Time (hours)
Southem Tract SWMP Charlotte 24-hr 1-yr 24.00 hrs 1 yr- 24 hr Rainfall=2.58"
Prepared by Kimley-Horn and Associates, Inc. Printed 11/24/2008
HydroCAM 8.50 s/n 005123 @2007 HydroCAD Software Solutions LLC Paoe 7
Summary for Subcatchment 6S: Post-dev DA -2
[49] Hint: Tc<2dt may require smaller dt
Runoff = 24.36 cfs @ 12.41 hrs, Volume= 3.098 af, Depth> 1.52"
' Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs
Charlotte 24-hr 1-yr 24.00 hrs 1 yr - 24 hr Rainfall=2.58
Area (ac) CN Description
24.400 89
24.400 Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
5.0 Direct Entry,
Subcatchment 6S: Post-dev DA-2
Hydrograph
26 _ _ _ ¦ Runoff
24.36 cfs
' 24 Charlotte 24-hr
22' 1 24.00 hrs 1 yr - 24 hr
20- Rainfall=2.58"
18Runoff Area=24.400 ac
16-
14- Runoff Volume=3.098 of
U. 12 Runoff Depth>1.52"
10- Tc=5.0 min
6 CN=89
6-
2
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
Time (hours)
Southem Tract SWMP Charlotte 24-hr 1-yr 24.00 hrs 1 yr - 24 hr Rainfall=2.58"
Prepared by Kimley-Horn and Associates, Inc. Printed 11/24/2008
HydroCAD® 8.50 s/n 005123 @2007 HydroCAD Software Solutions LLC Page 8
Summary for Subcatchment 8S: Post-dev UND DA-2
[49] Hint: Tc<2dt may require smaller dt
Runoff = 1.27 cfs @ 12.50 hrs, Volume= 0.193 af, Depth> 0.39"
Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs
Charlotte 24-hr 1-yr 24.00 hrs 1 yr - 24 hr Rainfall=2.58"
Area (ac) CN Description
5.930 67
5.930 Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
5.0 Direct Entry,
Subcatchment 8S: Post-dev UND DA-2 --
Hydrograph
¦ Runoff
1.27 cfs
Charlotte 24-hr '
1-yr 24.00 hrs 1 yr - 24 hr
1 Rainfall=2.58" '
Runoff Area=5.930 ac
Runoff Volume=0.193 of
Runoff Depth>0.39"
Tc=5.0 min
CN=67
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
Time (hours)
Southern Tract SWMP Charlotte 24-hr 1-yr 24.00 hrs 1 yr - 24 hr Rainfall=2.58"
Prepared by Kimley-Horn and Associates, Inc. Printed 11/24/2008
HydroCAM 8.50 s/n 005123 @2007 HydroCAD Software Solutions LLC Page 9
Summary for Pond 3P: Pond 1
Inflow Area = 7.150 ac, 0.00% Impervious, Inflow Depth > 2.14" for 1 yr - 24 hr event
Inflow = 9.25 cfs @ 12.40 hrs, Volume= 1.274 of
Outflow = 1.40 cfs @ 13.57 hrs, Volume= 0.569 af, Atten= 85%, Lag= 70.4 min
Primary = 1.40 cfs @ 13.57 hrs, Volume= 0.569 of
Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs
Peak Elev= 728.03'@ 13.57 hrs Surf.Area= 19,993 sf Storage= 35,851 cf
Plug-Flow detention time= 303.6 min calculated for 0.569 of (45% of inflow)
Center-of-Mass det. time= 180.0 min ( 971.7 - 791.7 )
Volume Invert Avail.Storage Storage Description
#1 726.00' 130,637 cf Custom Stage Data (Prismatic) Listed below (Recalc)
Elevation Surf.Area Inc.Store Cum.Store
(feet) (sq-ft) (cubic-feet) (cubic-feet)
726.00 14,257 0 0
727.00 18,100 16,179 16,179
728.00 19,930 19,015 35,194
729.00 21,832 20,881 56,075
730.00 23,807 22,820 78,894
731.00 25,853 24,830 103,724
732.00 27,972 26,913 130,637
Device Routing Invert Outlet Devices
#1 Primary 726.00' 36.0" x 51.0' long Culvert RCP, square edge headwall, Ke= 0.500
Outlet Invert= 725.00' S=0.0196'/' Cc= 0.900 n=0.013
#2 Device 1 726.00' 2.3" Vert. Orifice/Grate C= 0.600
#3 Device 1 727.75' 2.50' W x 0.75'H Vert. Orifice/Grate C=0.600
#4 Device 1 729.00' 2.50' W x 0.67' H Vert. Orifice/Grate C=0.600
#5 Device 1 729.50' 3.00' x 4.00' Horiz. Orifice/Grate Limited to weir flow C=0.600
Primary OutFlow Max=1.40 cfs @ 13.57 hrs HW=728.03' (Free Discharge)
L1=Culvert (Passes 1.40 cfs of 24.75 cfs potential flow)
2=Orifice/Grate (Orifice Controls 0.19 cfs @ 6.70 fps)
3=Orifice/Grate (Orifice Controls 1.21 cfs @ 1.71 fps)
-Orifice/Grate (Controls 0.00 cfs)
-5--Orifice/Grate (Controls 0.00 cfs)
Southern Tract SWMP Charlotte 24-hr 1-yr 24.00 hrs 1 yr - 24 hr Rainfall=2.58"
Prepared by Kimley-Horn and Associates, Inc. Printed 11/24/2008
HydroCAM 8 50 s/n 005123 @2007 HydroCAD Software Solutions LLC Page 10
Pond 3P: Pond 1
Hydrograph
¦ Inflow
¦ Primary v
3
0
LL
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 11 2s L4
Time (hours)
Southern Tract SWMP Charlotte 24-hr 1-yr 24.00 hrs 1 yr - 24 hr Rainfall=2.58"
Prepared by Kimley-Horn and Associates, Inc. Printed 11/24/2008
HydroCAM 8.50 s/n 005123 @2007 HydroCAD Software Solutions LLC Page 11
Summary for Pond 7P: Pond 2
Inflow Area 24.400 ac, 0.00% Impervious, Inflow Depth > 1.52" for 1 yr - 24 hr event
Inflow 24.36 cfs @ 12.41 hrs, Volume= 3.098 of
Outflow = 0.35 cfs @ 24.00 hrs, Volume= 0.338 af, Atten= 99%, Lag= 695.4 min
' Primary = 0.35 cfs @ 24.00 hrs, Volume= 0.338 of
Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs
Peak Elev= 721.69'@ 24.00 hrs Surf.Area= 49,464 sf Storage= 120,244 cf
Plug-Flow detention time= 434.7 min calculated for 0.338 of (11 % of inflow)
Center-of-Mass det. time= 254.0 min ( 1,085.2 - 831.2 )
Volume Invert Avail.Storage Storage Description
#1 719.00' 301,703 cf Custom Stage Data (Prismatic) Listed below (Recalc)
Elevation Surf.Area Inc.Store Cum.Store
(feet) (sq-ft) (cubic-feet) (cubic-feet)
719.00 38,235 0 0
720.00 44,277 41,256 41,256
721.00 47,329 45,803 87,059
722.00 50,442 48,886 135,945
' 723.00 53,616 52,029 187,974
724.00 56,850 55,233 243,207
725.00 60,143 58,497 301,703
Device Routing Invert Outlet Devices
#1 Primary 719.00' 36.0" x 147.0' long Culvert RCP, square edge headwall, Ke= 0.500
Outlet Invert= 716.00' S= 0.02047' Cc= 0.900 n= 0.013
#2 Device 1 719.00' 2.9" Vert. Orifice/Grate C= 0.600
#3 Device 1 723.60' 4.00' x 3.00' Horiz. Orifice/Grate Limited to weir flow C=0.600
#4 Device 1 722.00' 1.50' W x 0.50'H Vert. Orifice/Grate C=0.600
Primary OutFlow Max=0.35 cfs @ 24.00 hrs HW=721.69' (Free Discharge)
L1=Culvert (Passes 0.35 cfs of 37.24 cfs potential flow)
2=Orifice/Grate (Orifice Controls 0.35 cfs @ 7.71 fps)
' 3=Orifice/Grate ( Controls 0.00 cfs)
-Orifice/Grate ( Controls 0.00 cfs)
Southern Tract SWMP Charlotte 24-hr 1-yr 24.00 hrs 1 yr- 24 hr Rainfall=2.58"
Prepared by Kimley-Horn and Associates, Inc. Printed 11/24/2008
HydroCAD® 8.50 s/n 005123 @2007 HydroCAD Software Solutions LLC Page 12
Pond 7P: Pond 2
Hydrograph
¦ Inflow
¦ Primary
v
3
0
LL
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
Time (hours)

1
1
1
1
1
1
Southern Tract SWMP Charlotte 24-hr 1-yr 24.00 hrs 1 yr - 24 hr Rainfall=2.58"
Prepared by Kimley-Horn and Associates, Inc. Printed 11/24/2008
HydroCAD® 8.50 s/n 005123 @2007 HydroCAD Software Solutions LLC Page 13
Summary for Pond 8P: Outfall 1
[40] Hint: Not Described (Outflow= Inflow)
Inflow Area = 8.300 ac, 0.00% Impervious, Inflow Depth > 0.91" for 1 yr - 24 hr event
Inflow = 1.51 cfs @ 13.52 hrs, Volume= 0.632 of
Primary = 1.51 cfs @ 13.52 hrs, Volume= 0.632 af, Atten= 0%, Lag= 0.0 min
Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs
Pond 8P: Outfall 1
Hydrograph
1
0
LL
¦ Inflow
¦ Primary
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
Time (hours)
u
Southern Tract SWMP Charlotte 24-hr 1-yr 24.00 hrs 1 yr - 24 hr Rainfall=2.58"
Prepared by Kimley-Horn and Associates, Inc. Printed 11/24/2008
HydroCAD® 8.50 s/n 005123 @2007 HydroCAD Software Solutions LLC Page 14
Summary for Pond 9P: Outfall 2
[40] Hint: Not Described (Outflow= Inflow)
Inflow Area = 30.330 ac, 0.00% Impervious, Inflow Depth > 0.21" for 1 yr - 24 hr event
Inflow = 1.51 cfs @ 12.51 hrs, Volume= 0.530 of
Primary = 1.51 cfs @ 12.51 hrs, Volume= 0.530 af, Atten= 0%, Lag= 0.0 min
Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs
Pond 9P: Outfall 2
Hydrograph
v
0
U.
1
I
77
J

¦ Inflow '
¦ Primary
L 1-1

C

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
Time (hours)