20081213 Ver 2_Stormwater Info_20081110

¦
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
? ? ? Kimley-Horn
and Associates, Inc.
o ?
G o08
OS 9 S5I

This document, together with the concepts and designs presented herein, as an instrument of service, is intended only for the specific '
purpose and client for which it was prepared. Reuse of and improper reliance on this document without written authorization and
adaptation by Kimley-Hom and Associates, Inc. shall be without liability to Kimley-Hom and Associates, Inc.
' SOUTH TRACT CITY BOULEVARD DEVELOPMENT
CHARLOTTE, NORTH CAROLINA
' STORMWATER MANAGEMENT CALCULATIONS
Prepared for:
Crescent Resources, LLC
400 S. Tryon Street, Suite 1300
Charlotte, North Carolina 28202
r
' Prepared by:
Kimley-Horn and Associates, Inc.
' 4651 Charlotte Park Drive, Suite 300
Charlotte, North Carolina 28217
C A R O
: Q S A
O
' NOVEMBER 2008
KHA Ref: 018253026
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
STORMWA TER M,4NAGEA ENT 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
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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 1.00 cfs
DA-2 1.57 cfs 1.43 cfs
' STORMWA TER MANAGEMENT CALCULATIONS
South Tract City Boulevard Development, Charlotte, NC
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.
STORMWA TER MANAGEMENT CALCULATIONS
South Tract City Boulevard Development, Charlotte, NC
Ki\CHL-LDEV\018253 Crescent\022\1Parcel J\Cnlculntlons\Eroslon Control\Solls and Vlclnlty Mnp.dwg

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' m CRESCENT RESOURCES VICINITY MAP FIGURE
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Kimley-Horn and Associates, Inc. SOUTH TRACT PARCEL NTS
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' TMS DOCUMENT. TOGETHER RLTH THE CONCEPTS AND DE9GS PRESENTED HEREK AS AN INSTRUMENT OF SERVICE, IS INTENDED OILY FOR THE PURPOSE AND CLIENT FOR NEYCII IT WAS PREPARED. REUSE
OF AND WPROPER RELIANCE ON THIS DOGAIDR WITHOUT NUrIEN AUMMZA71ON AND ADAPTATION BY IOYtEY-NORM AND ASSOCIATES. INC SHALL BE WTHOUT LIABILITY TO M LEY-HORN AND ASSOCIATES INC.
rlmm0 CRESCENT RESOURCES SCS SOIL SURVEY FIGURE
Kimley-Horn and Associates, inc. SOUTH TRACT PARCELS NT$ 2
TILS DOMMENT. TOGETHER RTTI THE OONCEPTS AND DESIGNS PRESENTED HEREIN, AS AN NSIRUWNT OF SERVICE, IS INTENDED ONLY FOR THE PURPOSE AND CLIENT FOR NXCH IT WAS PREPARED. REUSE
OF AND NPROPET RELIANCE ON THIS DOQRIENT IMTHOUT NWf1EN AUTHORIZATION AND ADAPTATION BY pMIEY-HORN AND ASSOgA7E3. INC. SHAH BE VATHOUT LIABILITY TO RIYIEY-HORN AND ASSDUATS. NO
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PRE-DEVELOPMENT
' WATERSHED MAP

' STORMWA TER MANAGEMENT CALCULATIONS
South Tract City Boulevard Development, Charlotte, North Carolina
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POST-DEVELOPMENT
WATERSHED MAP

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STORMWA TER MANAGEMEATT CALCULATIONS
South Tract City Boulevard Development, Charlotte, North Carolina
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D
WET POND CALCULATIONS
' STORMWA TER MANAGEMENT CALCULATIONS
South Tract City Boulevard Development, Charlotte, North Carolina

1
Kimley-Horn
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: 10/27/2008
Revised by: Date:
Site Information
Sub Area Location: Drainage Area 1
Drainage Area (DA) = 7.2 Acres
Impervious Area (IA) = 5.8 Acres
Percent Impervious (1) = 80.0 %
Required Surface Area
Permanent Pool Depth: 4.25 ft
SA/DA = 3.65 (90% TSS Removal via Pond)
Min Req'd Surface Area = 11448 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) = 0.77 in/in
Storage Volume Required = 20125 cf (above Permanent Pool)
Elevations Area (s.f.)
Bank Elevation = 732.00 ft
Top of Pond Elevation = 732.00 ft
' Temporary Pool Elevation = 727.60 ft 16,278
Permanent Pool Elevation = 726.00 ft 11,541
Shelf Beginning Elevation = 726.50 ft
Forebay Weir = 728.00 ft
Shelf Ending Elevation = 725.50 ft
Bottom Elevation = 718.00 ft
' Wet Basin Areas/Volumes
Area @ Top of Temporary Pool = 16278 sf (Elevation = 727.60)
Area @ Top of Permanent Pool = 11541 sf (Elevation = 726.00 )
Volume of Temporary Storage = 22255 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 ( 11541 > 11448) sf
Volume of Storage Provided 22255 cf
' Total Volume Sufficient (yes/no)? Yes
Orifice Size = 2.30 inches
i

WET DETENTION BASIN
Project Information
Project Name: Belgate - Southern Tract
KHA Project #: 018253026
Designed by: BRR Date: 4/1/2008
Revised by: Date:
Revised by: Date:
Site Information
Sub Area Location: Drainage Area 1
Drainage Area (DA) = 7.2 Acres
Impervious Area (IA) = 5.8 Acres
Percent Impervious (1) = 80.0 % (Drainage Area)
Orifice Sizing
Q2 Days = 0.1288 cfs
Q5 Days = 0.0515 cfs
Orifice Size = 2.30 in
Q orifice = 0.098 cfs
Drawdown Time = 2.6 days
(Flowrate required for a 2 day drawdown)
(Flowrate required for a 5 day drawdown)
(Diameter)
less than 5 days (yes/no) ? yes
greater than 2 days (yes/no) ? yes
Orifice Equation: Q=CAgd(2gh) Q2 < Q < Q5
c = 0.6
A9= Area of Pipe = n/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

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KimleyHorn
CE" 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: Date:
Site Information
Sub Area Location: Drainage Area 2
Drainage Area (DA) = 23.9 Acres
Impervious Area (IA) = 16.1 Acres
Percent Impervious (1) = 67.5 %
Required Surface Area
Permanent Pool Depth: 4.25 ft
SA/DA = 2.975 (90% TSS Removal via Pond)
Min Req'd Surface Area = 30985 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) = 0.66 in/in
Storage Volume Required = 57036 cf (above Permanent Pool)
Elevations Area (s.f.)
Bank Elevation = 725.00 ft
Top of Pond Elevation = 725.00 ft
Temporary Pool Elevation = 720.70 ft 39,047
Permanent Pool Elevation = 719.00 ft 31,750
Shelf Beginning Elevation = 719.50 ft
Forebay Weir = 722.00 ft
Shelf Ending Elevation = 718.50 ft
Bottom Elevation = 712.00 ft
Wet Basin Areas/Volumes
Area @ Top of Temporary Pool = 39047 sf (Elevation = 720.70)
Area @ Top of Permanent Pool = 31750 sf (Elevation = 719.00)
Volume of Temporary Storage = 60177 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/n o)? Yes ( 31750 > 30985) sf
Volume of Storage Provided 60177 cf
Total Volume Sufficient (yes/no)? Yes
Orifice Size = 2.70 inches
r
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WET DETENTION BASIN
Project Information
Project Name: Belgate - Southern Tract
KHA Project #: 018253026
Designed by: BRR Date:
Revised by: Date:
Revised by: Date:
Site Information
Sub Area Location: Drainage Area 2
Drainage Area (DA) = 23.9 Acres
Impervious Area (IA) = 16.1 Acres
Percent Impervious (1) = 67.5 _% (Drainage Area)
Orifice Sizing
Q2 Days = 0.3482 cfs (Flowrate required for a 2 day drawdown)
Qs Days = 0.1393 cfs (Flowrate required for a 5 day drawdown)
Orifice Size = 2.70 in (Diameter)
Q orifice = 0.139 cfs
Drawdown Time = 5 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 = n/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
10/19/2008

ANTI-FLOTATION DEVICE CALCULATIONS

1 STORMWA TER MANAGEMENT CALCULATIONS
South Tract City Boulevard Development, Charlotte, North Carolina
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P-=FJ mole}-H-
IN.- WASOa W,1.
Project Information
Pond 1
NCDENR ANTIFLOATATION DEVICE DESIGN CALCULATIONS
(per NCDENR Manual)
Project Name: Belgate - Southern Tract
KHA Project #: 018253026
Designed by: BRR Date: 11/3/2008
Revised by: Date:
Revised by: Date:
Revised by: Date:
Drainage Area Information:
Drainage Area (ac) = 7.20
Flow (Qs) (cfs) = 12.8
Storage Dimensions:
Basin Side Slopes LX: 1 ) = 3.0 (3:1 max side slopes)
Storage Depth 'R' (ft) = 8.0
Top of Basin Elevation
Temporary Pool Elevation
Permanent Pool Elevation
Bottom of Basin Elevation
Elev (it) Area SF Cumulative Volume (CF)
732.00 27,972
730.00 23,807 125,006
727.60 16,278 76,904
726.00 11,541 54,649
723.00 8,218 25,011
720.00 4,215 6,361
718.00 2,146 0

Sizing of Antiflotation Block:
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 (of) = 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) = 4.4
Length (If) = 4.4
Height (If) = 4.D0
Weight of Anchor (lb) = 6,784 O.K. - Minimum Required Weight
Sizing of Emergency Spillway:
Q50 (ds) = 12.8
Q.N..y (ds) = 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 it min. above sediment storage depth)
Freeboard (ft) = 1.04 (1 ft minimum)
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`? 8b 0.SSOO8IPS, IK.
NCDENR ANTIFLOATATION DEVICE DESIGN CALCULATIONS
(per NCDENR Manual)
Project Information
Project Name: Belgate - Southern Tract
KHA Project #: 018253026
Designed by: BRR Date: 11/312008
Revised by: Date:
Revised by: Date:
Revised by: Dale:
Pond 7
Drainage Area Information:
Drainage Area (ac) = 23.90
Flow (Q.) (cfs) = 16.7
Storage Dimensions:
Basin Side Slopes LX-: 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 53,616 319,446
Temporary Pool Elevation 720.60 38,785 208,565
Permanent Pool Elevation 719.00 31,750 152,137
716.00 22,055 71,429
714.00 17,794 31,580
Bottom of Basin Elevation 712.00 13,786 0
Sizing of Antiflotation Block:
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) = 84.0
Weight of Water Displaced (lb) = 5,242
Min. Required Weight of Anchor Block (Ib) = 5,766 (1.1 factor of safety)
Anchor Size:
Width (If) = 4.1
Length (If) = 4.1
Height (If) = 4.00
Weight of Anchor (lb) = 5,890 O.K. > Minimum Required Weight
Sizing of Emergency Spillway:
Q? (cfs) = 16.7
Q...,y (cfs) = 16.7 (Riser ignored)
Water Depth Over Spillway (ft) = 0.5
Spillway Length (ft) = 40.0 (10 It minimum spillway length, Cw=2.7)
Spillway Crest Elevation (ft) = 723.7 (1 ft min. above sediment storage depth)
Freeboard (ft) = 1.01 (1 ft minimum)
Page 1 of 1

1

1

1

1

1

VOLUME AND SURFACE AREA TABLES
' STORMWA TER MANAGEMENT CALCULATIONS
South Tract City Boulevard Development, Charlotte, North Carolina
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' WET DETENTION BASIN
SUPPLEMENT FORMS
' STORMWATER MANAGEMENT CALCULATIONS
South Tract City Boulevard Development, Charlotte, North Carolina
OTIMA
Affl*W
r_ A
NCDENR
Permit No.
(to be provided by DWQ)
o?oF W A rFRO?
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.
L PROJECT INFORMATION
Project name Belgate Southern Tract
Contact person Beverly Rosenbloom, El
Phone number 704-319-7699
Date 10/24/2008
Drainage area number 2
Ih DESIGN INFORMATION
Site Characteristics
Drainage area 1,041,519.60 ff2
Impervious area 702,622.80 f 2
% impervious 67.46 %
Design rainfall depth 1.00 in
Storage Volume: Non-SR Waters
Minimum volume required 57,036.00 ft3
Volume provided 60,177.00 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 0.74 (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 21.76 ft3/sec
Pre/Post 1-yr, 24-hr peak flow control 20.19 ft3/sec
Basin Elevations
Basin bottom elevation 712.00 ft
Sediment cleanout elevation 713.00 ft
Bottom of shelf elevation 718.50 ft
Permanent pool elevation 719.00 ft
SHWT elevation 708.00 ft
Top of shelf elevation 719.50 ft
Temporary pool elevation 720.70 ft
Form SW401-Wet Detention Basin-Rev.4
Parts I. & II. Design Summary, Page 1 of 2
Permit No.
(to be provided by DWQ)
II. DESIGN INFORMATION
Volume and Surface Area Calculations
SA/DA ratio 2.98 (unitless)
Surface area at the bottom of shelf 27,740.00 ft2
Volume at the bottom of shelf 133,518.00 ft3
Permanent pool, surface area required 30,985.00 ff
Permanent pool, surface area provided 31,750.00 ff OK
Permanent pool volume 148,391.00 ft3
Average depth for SA/DA tables 4.67 ft OK
Surface area at the top of shelf 35,931.00 ff2
Volume at the top of shelf 165,311.00 ft3
Forebay volume 28,095.00 ft3
Forebay % of permanent pool volume 18.93 % OK
Temporary pool, surface area provided 39,047.00 ft2
Drawdown Calculations
Treatment volume drawdown time
Treatment volume discharge rate
Pre-development 1-yr, 24-hr discharge
Post-development 1-yr, 24-hr discharge
Additional Information
Diameter of orifice
Design TSS removal
Basin side slopes
Vegetated shelf slope
Vegetated shelf width
Length of flowpath to width ratio
Length to width ratio
Trash rack for overflow & orifice?
Freeboard provided
Vegetated filter provided?
Recorded drainage easement provided?
Capures all runoff at ultimate build-out?
Drain mechanism for maintenance or emergencies
5.00 days OK
0.14 ft3/s
1.57 ft3/s OK
1.43 ft3/s OK
2.7 in
90 %
3.00 :1 OK
10.00 :1 OK
10.00 ft OK
4.10 :1 OK
3.20 :1 OK
Y (Y or N) OK
1.40 ft OK
N (Y or N) Design must be based on 90% TSS removal
Y (Y or N) OK
Y (Y or N) OK
24-HR EMERGENCY PUMP
Form SW401-Wet Detention Basin-Rev.4 Parts I. & II. Design Summary, Page 2 of 2
Permit
(to be provided by DWQ)
Ill. 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.
_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.
B12 tZ 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.
9rZK- C-4 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.
$IZ-l? - _C-3
_C-4
Sce a'1tvckod
AL afl
IL _Calc book-
-Attached-
, U- -Attached-
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.
5. A table of elevations, areas, incremental volumes & accumulated volumes for overall pond and for forebay,
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.
7. The supporting calculations.
8. A copy of the signed and notarized operation and maintenance (0&M) agreement.
9. A copy of the deed restrictions (if required).
X12 ?- -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
Permit
' NCDENR
(to be provided by DWQ)
O?OF W ATF9OG
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.
G'PROJECT INFORMATION
Project name Belgate Southern Tract
Contact person Beverly Rosenbloom, El
Phone number 704-319-7699
Date 11/6/2008
' Drainage area number 1
II, DESIGN INFORMATION
Site Characteristics
' Drainage area 313,632.00 fe
Impervious area 250,905.60 fe
% impervious 80.00 %
Design rainfall depth 1.00 in
'
Storage Volume: Non-SR Waters
Minimum volume required 20,125.00 ft3
Volume provided 22,255.00 ff3
Storage Volume: SR Waters
1-yr, 24-hr runoff depth in
Pre-development 1-yr, 24-hr runoff ff3
' 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 0.82 (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 8.46 ft3/sec
Pre/Post 1-yr, 24-hr peak flow control 5.83 ft3/sec
Basin Elevations
Basin bottom elevation 718.00 ft
Sediment cleanout elevation 719.00 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 727.60 ft
Form SW401-Wet Detention Basin-Rev.4
Parts i. & H. Design Summary, Page 1 of 2
Permit
(to be provided by DWQ)
II. DESIGN INFORMATION
Volume and Surface Area Calculations
SA/DA ratio 3.65 (unitless)
Surface area at the bottom of shelf 8,955.00 ff2
Volume at the bottom of shelf 45,466.00 ft3
Permanent pool, surface area required 11,448.00 ftz
Permanent pool, surface area provided 11,541.00 ff2 OK
Permanent pool volume 50,590.00 ff3
Average depth for SA/DA tables 4.38 ft OK
Surface area at the top of shelf 14,328.00 ft2
Volume at the top of shelf 57,058.00 ff3
Forebay volume 9,344.00 ft3
Forebay % of permanent pool volume 18.47 % OK
Temporary pool, surface area provided 16,278.00 ff
Drawdown Calculations
Treatment volume drawdown time 2.60 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 1.00 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 overf low & 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)
I]I. 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.
Paget 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.
Ott 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.
C-4_ 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.
_ _C-4 5. A table of elevations, areas, incremental volumes & accumulated volumes for overall pond and for forebay,
eu a{fgc to verify volume provided.
' q bra ed EG
-?S
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 (O&M) agreement.
-Attached- 9. A copy of the deed restrictions (if required).
?7 4- -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
/i?? Kimley-Hom
r2 and Associates, Inc.
Pre vs. Post Runoff Analysis
Composite Curve Number (CN)
Project Information
Project Name: Parcel J
KHA Project #: 018253020
Designed by: BRR Date: 10/6/2008
Revised by: Date:
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 Composite
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 5.76 564 98
Mecklenburg,
Enon, Wilkes
Open Space - Good Condition
C
74
1.44
107
74
7.20 670.77 93.20

UND DA-1 OUTFALL 1 Mecklenburg,
Enon, Wilkes
Open Space - Good Condition
C
74
1.10
81
74
{ - 1.10 81.50 74.00
DA-2 POND 2 Impervious 98 13.23 1297 98
Mecklenburg,
Enon, Wilkes
Open Space - Good Condition
C
74
0.90
67
74
Cecil Open Space - Good Condition B 61 5.71 348 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
? - 23.91 2080.60 87.03

UND DA-2
OUTFALL 2 Mecklenburg,
Enon, Wilkes
Open Space - Good Condition
C
74
2.65
196
74
Cecil Open Space - Good Condition B 61 3.76 230 61
6.42 425.96 66.38
Total Post-development Area = 38.62
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 AStormwater Calculations_2008-10-06.As 1 of 1
TIME OF CONCENTRATION
CALCULATIONS
EROSION CONTROL CALCULATIONS
New Towne Gardens, Union County, North Carolina

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HYDROCAD HYDROLOGY REPORT
EROSION CONTROL CALCULATIONS
New Towne Gardens, Union County, North Carolina
is) 2S (4S)
Pre-dev DA-1 Post-d v DA-1 Post-dev ND DA-1
3P 8P
Pond 1 Outfall 1
(5S) 6S i
Pre-dev DA-2 Post-d v DA-2 Post-dev ND DA-2
-?7 41
7P 9P
Pond 2
Outfall 2
Subca Reach and Link
Belgate - 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 11/5/2008
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=7.200 ac 0.00% Imperious Runoff Depth>1.85"
Tc=5.0 min CN=93 Runoff=8.46 cfs 1.112 of
Subcatchment 4S: Post-dev UND DA-1 Runoff Area=1.100 ac 0.00% Imperious Runoff Depth>0.65"
Tc=5.0 min CN=74 Runoff=0.45 cfs 0.060 of
Subcatchment 5S: Pre-dev DA-2 Runoff Area=27.280 ac 0.00% Imperious 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=23.910 ac 0.00% Imperious Runoff Depth>1.38"
Tc=5.0 min CN=87 Runoff=21.76 cfs 2.744 of
Subcatchment 8S: Post-dev UND DA-2 Runoff Area=6.420 ac 0.00% Imperious Runoff Depth>0.36"
Tc=5.0 min CN=66 Runoff=1.22 cfs 0.191 of
Pond 3P: Pond 1 Peak Elev=727.95' Storage=32,636 cf Inflow=8.46 cfs 1.112 of
Outflow=0.93 cfs 0.443 of
Pond 7P: Pond 2 Peak Elev=721.82' Storage=106,572 cf Inflow=21.76 cfs 2.744 of
Outflow=0.31 cfs 0.297 of
Pond 8P: Outfall 1 Inflow=1.00 cfs 0.503 of
Primary=1.00 cfs 0.503 of
Pond 9P: Outfall 2 Inflow=1.43 cfs 0.489 of
Primary=1.43 cfs 0.489 of
Total Runoff Area = 75.990 ac Runoff Volume = 4.991 of Average Runoff Depth = 0.79"
100.00% Pervious= 75.990 ac 0.00% Impervious= 0.000 ac
Belgate - 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 11/5/2008
HydroCAD® 8.50 s/n 005123 @2007 HydroCAD Software Solutions LLC Page 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
Subcatchment 1 S: Pre-dev DA-1
Hydrograph
I ? Runoff
2.63 cfs
Charlotte 24-hr
1-yr 24.00 hrs 1 yr 24 hr ?
Rainfall =2.58"
2
Runoff Area=10.080 ac
Runoff Volume=0.443: of 'rl
Runoff Depth>0.53"
Tc=25.2_min
CN=71 l
0
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
Belgate - 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 11/5/2008
HydroCAD® 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 = 8.46 cfs @ 12.40 hrs, Volume= 1.112 af, Depth> 1.85'
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
7.200 93
7.200 Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
5.0 Direct Entry, From spreadsheet
1
1
1
1
1
1
1
Beigate - 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 11/5/2008
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 = 0.45 cfs @ 12.45 hrs, Volume= 0.060 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
1.100 74
1.100 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

of

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 Belgate - 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 11/5/2008
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
', I 0 Runoff
1.57 cfs
Charlotte 24-hr
1-yr 2.4.00 hrs 1 yr - 24 hr f?
Rainfall=2.58'
'
...Runoff Area. 27,280 ac ?Y ..
Runoff Volume=0.441: of f
v
Runoff Depth>0.19"
r
' Tc 25.0. min
CN=60
o
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)
Belgate - 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 11/5/2008
HydroCAD® 8.50 s/n 005123 © 2007 HydroCAD Software Solutions LLC Page 7
Summary for Subcatchment 6S: Post-dev DA-2
[49] Hint: Tc<2dt may require smaller dt
Runoff = 21.76 cfs @ 12.41 hrs, Volume= 2.744 af, Depth> 1.38"
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
23.910 87
23.910 Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
5.0 Direct Entry,
23
22
21
19
18
17
16
15
w 14
0 13 "
3 12
rL 11
10
Subcatchment 6S: Post-dev DA-2
Hydrograph
------- _
Runoff
i
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
Time (hours)
Belgate - Southern Tract SWMP Charlotte 24-hr 1-yr 24.00 hrs 1 yr- 24 hr Rainf611=2.58"
Prepared by Kimley-Horn and Associates, Inc. Printed 11/5/2008
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 = 1.22 cfs @ 12.51 hrs, Volume= 0.191 af, Depth> 0.36"
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
6.420 66
6.420 Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (fUsec) (cfs)
5.0 Direct Entry,
Subcatchment 8S: Post-dev UND DA-2
Hydrograph
Runoff
1.22 cfs
Charlotte 24-hr
1-yr_24.0.0 _hrs 1 yr - 24_hr. .......
' Rainfall'=2.58"
Runoff Area=6! 420 ac a
N
Runoff Vol ume=0.191 of
LL Runoff Depth>0.36"
Tc=5.0 min t?f
CN=66
o-
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)
Belgate - 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 11/5/2008
HydroCAD® 8.50 s/n 005123 @2007 HydroCAD Software Solutions LLC Page 9
Summary for Pond 3P: Pond 1
Inflow Area = 7.200 ac, 0.00% Impervious, Inflow Depth > 1.85" for 1 yr - 24 hr event
Inflow = 8.46 cfs @ 12.40 hrs, Volume= 1.112 of
Outflow = 0.93 cfs @ 14.23 hrs, Volume= 0.443 af, Atten= 89%, Lag= 109.4 min
Primary = 0.93 cfs @ 14.23 hrs, Volume= 0.443 of
Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs
Peak Elev= 727.95'@ 14.23 hrs Surf.Area= 19,319 sf Storage= 32,636 cf
Plug-Flow detention time= 322.2 min calculated for 0.443 of (40% of inflow)
Center-of-Mass det. time= 198.3 min ( 1,009.9 - 811.6 )
Volume Invert Avail.Storage Storage Description
#1 726.00' 128,745 cf Custom Stage Data (Prismatic) Listed below (Recalc)
Elevation Surf.Area Inc.Store Cum.Store
(feet) (sq-ft) (cubic-feet) (cubic-feet)
726.00 13,220 0 0
727.00 17,234 15,227 15,227
728.00 19,423 18,329 33,556
729.00 21,832 20,628 54,183
730.00 23,807 22,820 77,003
731.00 25,853 24,830 101,833
732.00 27,972 26,913 128,745
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=0.92 cfs @ 14.23 hrs HW=727.95' (Free Discharge)
'L1=Culvert (Passes 0.92 cfs of 23.17 cfs potential flow)
2=Orifice/Grate (Orifice Controls 0.19 cfs @ 6.56 fps)
3=Orifice/Grate (Orifice Controls 0.73 cfs @ 1.44 fps)
-Orifice/Grate ( Controls 0.00 cfs)
=Orifice/Grate ( Controls 0.00 cfs)
Belgate - 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 11/5/2008
HydroCAD® 8.50 s/n 005123 © 2007 HydroCAD Software Solutions LLC Page 10
Pond 3P: Pond 1
Hydrograph
Inflow
p Primary
w
v
3
0
U.
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)
Belgate - 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 11/5/2008
HydroCAD® 8.50 s/n 005123 @2007 HydroCAD Software Solutions LLC Page 11
Summary for Pond 7P: Pond 2
Inflow Area = 23.910 ac, 0.00% Impervious, Inflow Depth > 1.38" for 1 yr - 24 hr event
Inflow = 21.76 cfs @ 12.41 hrs, Volume= 2.744 of
Outflow = 0.31 cfs @ 24.00 hrs, Volume= 0.297 af, Atten= 99%, Lag= 695.2 min
Primary = 0.31 cfs @ 24.00 hrs, Volume= 0.297 of
Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs
Peak Elev= 721.82'@24.00 hrs Surf.Area= 42,040 sf Storage= 106,572 cf
Plug-Flow detention time= 420.6 min calculated for 0.297 of (11% of inflow)
Center-of-Mass det. time= 249.5 min ( 1,088.9 - 839.5 )
Volume Invert Avail.Storage Storage Description
#1 719.00' 275,997 cf Custom Stage Data (Prismatic) Listed below (Recalc)
Elevation Surf.Area Inc.Store Cum.Store
(feet) (sq-ft) (cubic-feet) (cubic-feet)
719.00 31,750 0 0
720.00 37,219 34,485 34,485
'
721.00 39,841 38,530 73,015
722.00 42,524 41,183 114,197
723.00 53,616 48,070 162,267
724.00 56,850 55,233 217,500
725.00 60,143 58,497 275,997
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=0.0204'/' Cc= 0.900 n=0.013
#2 Device 1 719.00' 2.7" 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=0.31 cfs @ 24.00 hrs HW=721.82' (Free Discharge)
t1=Culvert (Passes 0.31 cfs of 39.42 cfs potential flow)
2=Orifice/Grate (Orifice Controls 0.31 cfs @ 7.92 fps)
3=Orifice/Grate ( Controls 0.00 cfs)
-Orifice/Grate (Controls 0.00 cfs)
Belgate - Southern Tract SWMP Charlotte 24-hr 1-yr 24.00 hrs 1 yr - 24 hr Rainfall=2.58"
Belgate - 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 11/5/2008
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 > 0.73" for 1 yr - 24 hr event
Inflow = 1.00 cfs @ 14.16 hrs, Volume= 0.503 of
Primary = 1.00 cfs @ 14.16 hrs, Volume= 0.503 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
F-s Inflow
10 Primary
w
v
3
0
U.
U 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)
Belgate - 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 11/5/2008
HydroCAD® 8.50 s/n 005123 @2007 H droCAD 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 > 0.19" for 1 yr - 24 hr event
Inflow = 1.43 cfs @ 12.52 hrs, Volume= 0.489 of
Primary = 1.43 cfs @ 12.52 hrs, Volume= 0.489 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
Fq- Inflow
10 Primary
N
V
O
U.
U 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)