SW8991115_COMPLIANCE_20050411

STORMWATER DIVISION CODING SHEET
POST -CONSTRUCTION PERMITS
PERMIT NO.
SW X`7`�I�ISJ
DOC TYPE
El CURRENT PERMIT
❑ APPROVED PLANS
❑ HISTORICAL FILE
COMPLIANCE EVALUATION INSPECTION
DOC DATE
4 l j
YYYYMMDD

WArFR Michael F. Easley, Governor
O G William G. Ross, Jr., Secretary
r North Carolina Department of Environment and Natural Resources
0 Alan W. Klimek, P.E. Director
Division of Water Quality
April 11, 2005
Mr. Johnie Davis, President
Country Club Developers, Inc.
5018 Randall Parkway, Ste 3
Wilmington, NC 28403
NOTICE OF INSPECTION:
Country Club Villas @ Coastal Carolina
Stormwater Project No. SW8 991115
Pender County
Dear Mr. Davis:
Please find attached a copy of the completed form entitled "Stormwater Compliance Inspection
Report". The report summarizes the findings of a recent inspection of the project's Stormwater
controls conducted on April 5, 2005 to determine compliance with Stormwater Permit Number
SW8 991115 issued on April 10, 2000.
A summary of the findings and comments are noted under Section 4 of the report. Please
inform this Office in writing before May 10, 2005, of the specific actions that will be undertaken
and the time frame required to correct the deficiencies. Failure to provide the requested
information, when required, may initiate enforcement action. If you have any questions please
contact me at the Wilmington Regional Office, telephone number [phone].
Sincerely,
A -1k.
Gary Becher
Environmental Technician
EBlghb: S:IWQSISTORMWATIINSPECT1991115.Apr05
cc: Joseph_F-lll, P.E.(Joseph Hill, Jr. & Associates)
Wilmington Regional Office
North Carolina Division of Water Quality 127 Cardinal Drive Extension Phone [phone] Customer Servicel-877-623-6748
Wilmington Regional Once Wilmington, NC 28405-3845 FAX [phone] Internet: h2o.enr.state.nc.us One
NorthCarollina
An Equal Opportunity/Affirmative Action Employer — 50% Recycled110% Post Consumer Paper Naturtdbf

STORMWATER COMPLIANCE INSPECTION REPORT
2
Project Name: Country Club Villas @ Coastal Carolina Country Club
Project Number: sw8 991115 Control Measure: Wet Pond
Water Body: Burgaw Creek Classification: "C-Sw"
Directions to site: Wilmington East Rd. in Burgaw
Inspection Date: April 5, 2005
Weather Conditions: Warm & Sunny (70's)
3. Compliance Issues:
Y N
❑ ❑ The drainage area (including offsite) and built -upon area to the permitted
system are per the approved plan. No unpermitted offsite drainage enters
the system.
❑ ❑ All the built -upon area associated with the project is graded such that the
runoff drains to the system.
❑ ❑ For ponds/infiltration, the outlet/bypass structure relative elevations are
per the approved plan. (Must be verified via as -built survey if in question).
❑ ❑ The inlets and outlet structure are located per the approved plans and do
not cause short-circuiting.
❑ �( A trash rack is provided over the outlet weir and orifice.
❑ All slopes are grassed with permanent vegetation and are not eroding.
❑ ❑ Vegetated slopes are no steeper than 3:1.
❑ ❑ The approximate amount of permitted surface area has been provided.
(Must be verified via as -built survey or designer's certification.)
❑ ❑ Required drawdown devices are correctly sized per the approved plans.
All required design depths are provided.
❑ ❑ All required parts of the system are provided, such as a vegetated shelf,
and a forebay.
❑ X The designer's certification has been submitted.
❑ ❑ The required deed restrictions are correctly recorded and submitted.
❑ ❑ The number of lots or outparcels is per the permitted amount.
❑ ❑ The built -upon area on the lots or outparcels does not appear to exceed
the maximum amount (must be verified via as -built survey if in question)
❑ ❑ Curb outlet swales are constructed, located properly, are 100' long and
have dense vegetated cover.
❑ ❑ The road, cul-de-sac, parking lot and sidewalk widths are per the
approved plan.
❑ ❑ Required maintenance is being performed.
❑ ❑ Outparcels have their own offsite permit.
❑ ❑ For low density projects, roadside swales are 3:1, vegetated and stable.
❑ ❑ For low density projects, there are no unpermitted pipes on the project.

4. Required Actions: (Explain each deficiency and what needs to be done to bring
the system back into compliance)
(a) The Stormwater Outlet Structure is missing a trash rack on both the top and
the front of the structure.
(b) There is also a grate missing from the top of a drop inlet basin. The structure is
located close to the built apartment building. This open structure presents a
problem to children and adults alike. A grate or lid must be placed on this
structure immediately.
(c) A copy of the engineers/designers certificate must be sent to this office.
Inspector; Gary Beecher
Water Quality/Wilmington Regional Office: [phone] Ext 222
EBlghb: S:IWQSISTORMWATIINSPECT1991115.Apr05

Compliance Inspection Report
Permit: SW8991115 Effective: 04/10/00 Expiration: 04/10/10 Owner: Country Club Builders Inc
Project: Country Club Villas Coastal Carolina C
County: Fender
Region: Wilmington
Contact Person: Johnie W Davis Title: President
Directions to Project:
Type of Project: State Stormwater - HD - Detention Pond
Drain Areas:
On -Site Representative(s):
Related Permits:
Inspection Date: 02/01/2010 Entry Time: 10:00 AM
Primary Inspector: David W Cox
Secondary lnspector(s):
Reason for Inspection: Routine
Permit Inspection Type: State Stormwater
Facility Status: ❑ Compliant ■ Not Compliant
Question Areas:
N State Stormwater
(See attachment summary)
Exit Time: 11:00 AM
Phone: [phone]
Phone: [phone]
Inspection Type: Stormwater
Page: 1

Permit: SW8991115 Owner -Project: Country Club Builders Inc
Inspection Date: 02/01/2010 Inspection Type: Stormwater
Inspection Summary:
Engineer's Certwas requested on April 11, 2005 in a compliance letter.
In order to bring this system into compliance you must provide the following:
1. The required Engineer's Certification.
File Review
Is the permit active?
Signed copy of the Engineers certification is in the file?
Signed copy of the Operation & Maintenance Agreement is in the file?
Copy of the recorded deed restrictions is in the tile?
Comment: Failed to submit the required Engineer's Certificate.
Reason for Visit: Routine
Yes No NA NE
■ ❑ ❑ ❑
❑ ■ ❑ ❑
■ ❑ ❑ ❑
❑ ❑ ❑ ■
Page: 2

Compliance Inspection Report
Permit: SW8991115 Effective: 04/10/00 Expiration: 04/10/10 Owner: Country Club Builders Inc
Project: Country Club Villas Coastal Carolina C
County: Pender
Region: Wilmington
Contact Person: Johnie W Davis Title: President
Directions to Project:
Type of Project: State Stormwater - HD - Detention Pond
Drain Areas:
On -Site Representative(s):
Related Permits:
Inspection Date: 0210112010 Entry Time: 10:00 AM
Primary Inspector: David W Cox
Secondary Inspector(s):
Reason for Inspection: Routine
Permit Inspection Type: State Stormwater
Facility Status: ❑ Compliant ® Not Compliant
Question Areas:
® State Stormwater
(See attachment summary)
Exit Time: 11:00 AM
Phone: [phone]
Phone: [phone]
Inspection Type: Stormwater
Page: 1

Permit: SW8991115 Owner - Project: Country Club Builders Inc
Inspection Date: 02/01/2010 Inspection Type: Stormwater
Inspection Summary:
Engineer's Cert was requested on April 11, 2005 in a compliance letter.
In order to bring this system into compliance you must provide the following:
1. The required Engineer's Certification.
File Review
Is the permit active?
Signed copy of the Engineer's certification is in the fife?
Signed copy of the Operation & Maintenance Agreement is in the file?
Copy of the recorded deed restrictions is in the file?
Comment: Failed to submit the required Engineer's Certificate.
Reason for Visit: Routine
Page: 2

COUNTRY CLUB VILLAS AT COASTAL CAROLINA COUNTRY CLUB
Forebay Calculations
Provide 20% of Permanent Pool volume including area of forebay construction:
Permanent Pool Volume:
Pool Area @ Elev. 23.2' = 13,302 SF
Pond Area @ Elev. 19.2' = 5,454 SF
Pond Average Area = 9,378 SF
9,378 SF x 4.0' Depth = 37,512 CF Permanent Pool Volume
Temporary Pool Volume:
STORMWATER
13,302 Average Area x 0.5' Depth = 6,651 CF E C E I V
D
FEB 282000
Forebay Volume: M e LNG
Forebay Area @ Elev. 23.2' = 3,600 SF
Forebay Area @ Elev. 20.2' = 1,576 SF
Forebay Average Area = 2,588 SF
2,588 SF x 3.0' Depth = 7,764 CF Forebay Volume
7,764 CF = 37,512 CF = 20.6%
Forebay = 20.7% of Total Pond Volume
CC.SFWR CALCR1.doc Page 4 of 4

'- �
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1 �.�.
,.. �

. Permit No..��0
(to be provided by DWQ)
State of North Carolina
Department of Environment and Natural Resources
Division of Water Quality
STORMWATER MANAGEMENT PERMIT APPLICATION FORM
WET DETENTION BASIN SUPPLEMENT
This form may he photocopied far use as an original
DWQ Stormwater Management Plan Review:
A complete stormwater management plan submittal includes an application form, a wet detention basin
supplement for each basin, design calculations, and plans and specifications showing all basin and outlet
structure details.
I. PROJECT INFORMATION
Project Name: Country Club Developers, Inc.
Contact Person: Johnie Davis Phone Number: ( 910 _)392-4017______ _
For projects with multiple basins, specify which basin this worksheet applies to: NIA
elevations
Basin Bottom Elevation 19.2, ft.
Permanent Pool Elevation 23.2` ft.
Temporary Pool Elevation 237 ft.
r(WOM
(floor of the basin)
(elevation of the orifice)
(elevation of the discharge structure overflow)
Permanent Pool Surface Area 13,302 sq. ft. (water surface area at the orifice elevation)
Drainage Area
3.10 ac.
(on -site and off -site drainage to the basin)
Impervious Area
1.58 ac.
(on -site and off -site drainage to the basin)
volumes
Permanent Pool Volume
37,512 cu. ft.
(combined volume of main basin and.forebay)
Temporary Pool Volume
6,651 cu. ft.
(volume detained above the permanent pool)
Forebay Volume
7.503 cu. ft.
(approximately 20% of permanent pool)
Other parameters
SA/DA ` 4.4
Diameter of Orifice 1.25 in.
Design Rainfall 1.0 in.
Design TSS Removalz 90 %
(surface area to drainage area ratio from DWQ table)
(2 to 5 day temporary pool draw -down required)
(minimum 85% required)
CC -Form SWU-102 Rev 3.99Rl.doc
Pagel of 4

-- Footnotes:
When using the division SA/DA tables, the correct SAIDA ratio for permanent pool sizing should be computed based upon
the actual impervious % and permanent pool depth. Linear interpolation should be employed to determine the correct
value for non-standard table entries.
2 In the 20 coastal counties, the requirement for a vegetative filter may be waived if the wet detention basin is designed to
provide 90% TSS removal. The NCDENR BMP manual provides design tables for both 85% TSS removal and 90% TSS
removal.
lt. REQUIRED ITEMS CHECKLIST
The following checklist outlines design requirements per the Stormwater Best Management Practices Manual (N.C.
Department of Environment, Health and Natural Resources, February 1999) and Administrative Code Section: 15
A NCAC 2H .1008.
Initial in the space provided to indicate the following design requirements have been met and supporting
documentation is attached. If the applicant has designated an agent in the Stormwater Management Permit
Application Form, the agent may initial below. If a requirement has not been met, attach justification.
Applicants Initials
a. The permanent pool depth is between 3 and 6 feet (required minimum of 3 feet)
b. The forebay volume is approximately equal to 20% of the basin volume.
c. The temporary pool controls runoff from the design storm event.
d. The temporary pool draws down in 2 to 5 days.
e. If required, a 30-foot vegetative filter is provided at the outlet (include non -erosive flow
calculations)
f. The basin length to width ratio greater than 3:1.
g. The basin side slopes above the permanent pool are no steeper than 3:1.
h. A submerged and vegetated perimeter shelf with a slope of 6:1 or less (show detail)
i. Vegetative cover above the permanent pool elevation is specified.
j. A trash rack or similar device is provided for both the overflow and orifice.
k. A recorded drainage easement is provided for each basin including access to nearest right-of-
way.
1. If the basin is used for sediment and erosion control during construction, clean out of the basin
is specified prior to use as a wet detention basin.
m. A mechanism is specified which will drain the basin for maintenance or an emergency.
If. WET DETENTION BASIN OPERATION AND MAINTENANCE AGREEMENT
The wet detention basin system is defined as the wet detention basin, pretreatment including forebays and the
vegetated filter if one is provided.
This system (check one) 0 does X does not incorporate a vegetated filter at the outlet.
This system (check one) 0 does X does not incorporate pretreatment other than a forebay.
CC.Form SWU-102 Rev 3.99Rl.doc Page 2 of

Maintenance activities shall be performed as follows:
After every significant runoff producing rainfall event and at least monthly:
a. Inspect the wet detention basin system for sediment accumulation, erosion, trash accumulation,
vegetated cover, and general condition.
b. Check and clear the orifice of any obstructions such that drawdown of the temporary pool occurs
within 2 to 5 days as designed.
2. Repair eroded areas immediately, re -seed as necessary to maintain good vegetative cover, mow vegetative
cover to maintain a maximum height of six inches, and remove trash as needed.
3. Inspect and repair the collection system (i.e. catch basins, piping, swales, riprap, etc.) quarterly to maintain
proper functioning.
4. Remove accumulated sediment from the wet detention basin system semi-annually or when' depth is
reduced to 75% of the original design depth (see diagram below), Removed sediment shall be disposed of
in an appropriate manner and shall be handled in a manner that will not adversely impact water quality (i.e.
stockpiling near a wet detention basin or stream, etc.).
The measuring device used to determine the sediment elevation shall be such that it will give an accurate
depth reading and not readily penetrate into accumulated sediments.
When the permanent pool depth reads 3.0' feet in the main pond, the sediment shall be removed.
When the permanent pool depth reads 2.2' feet in the forebay, the sediment shall be removed.
BASIN DIAGRAM
ill in the blanks)
Permanent Pool Elevation 23.2'
Sediment Removal El.
Bottom Elevkion 20.2'S,/25%
FOREBAY
Sediment Removal Elevation _ _20-2` 6 75%
Bottom Elevation _ 19.2' 62
MAIN POND
5. Remove cattails and other indigenous wetland plants when they cover 50% of the basin surface. These
plants shall be encouraged to grow along the vegetated shelf and forebay berm.
6. If the basin must be drained for an emergency or to perform maintenance, the flushing of sediment through
the emergency drain shall be minimized to the maximum extent practical.
CC.Form SWU-102 Rev 3.99Rl.doc Page 3 of 4

7. All components of the wet detention basin shall be maintained in good working order.
I acknowledge and agree by my signature that I am responsible for the performance of the seven
maintenance procedures listed above. I agree to notify DWQ of any problems with the system or prior to
any changes to the system or responsible party.
Print Name: Johnie Davis
Title: President (Country Club Developers. Inc.) _
Address: 1111B The Cqpe Boulevard Wilmin ton N.C. 28412
Phone: [phone]
Signature:
Date:
Note: The legally responsible party should not be a homeowners association unless more than 50% of the lots have been
sold and a resident of the subdivision has been named the president.
I.
County o
, a Notary Public for the State of
do hereby certify that
0
personally appeared before me this day of , 1999, and acknowledge the
due execution of the forgoing wet detention basin maintenance requirements. Witness my hand and
official seal,
SEAL
My commission expires
CC.Form SWU-102 Rev 3.99Rl.doc Page 4 of

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CC.STWR CIR.doc
COUNTRY CLUB VILLAS AT
COASTAL CAROLINA COUNTRY CLUB
PENDER COUNTY
STORMWATER MANAGEMENT CALCULATIONS
October 1999
zs,�
4 3 E A L v1
is /a7�99
Prepared By:
JOSEPH S. HILL, JR. and ASSOCIATES
CONSULTING ENGINEERS and PLANNERS
1602 Harbour Drive
Wilmington, North Carolina 28401
[phone]
PV«115--

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CountU Club Villas at Coastal Carolina Country Club
CC.STWR CVR doc
1. Detention Pond Calculations
2. Forebay Calculations
3. Outlet Protection Design - 15", 18", 30" 0 Pipe
4. Pond Outlet Calculations
5. Swale Calculations

COUNTRY CLUB VILLAS AT
COASTAL CAROLINA COUNTRY CLUB
Stormwater Detention Pond Calculations
Stormwater runoff from the project will be retained in a wet detention
pond. This pond will store the runoff generated by 1 inch of rainfall. The stored
runoff will be discharged over a period of 4.2 days.
The pond area required to remove 90% of total suspended solids was
calculated using the SA/DA Percentage Chart (see chart) for North Carolina
coastal regions.
Runoff Calculations
Impervious Surfaces -
Building Rooftop (4,265 SF X 6 Bldgs) = 25,590 SF
Asphalt Street & Parking = 401248 SF
Sidewalks = 5'W x 600 LF = 3,000 SF
Total Impervious Surfaces
— 68,838 SF
Total Drainage Area
= 135,337 SF
Total Impervious Area
= 68,838 SF
Total Pervious Area
— 66,499 SF
1" Runoff from Impervious Surfaces = 0.083' x 68,838 SF = 5,714 CF
1" Runoff from Pervious Surfaces = 0.2 x 0,083' x 66,499 SF = 1,104 CF
Total runoff to be stored in pond = 61818 CF
= 51,135 Gals
Detention Pond Calculations
Pond Surface area @ Storage Pool Elev. of 23.7' = 14,112 SF
Pond Surface area @ Permanent Pool Elev. of 23.2' = 13,302 SF
Average Pond Surface Area = 13,707 SF
Pond Storage Volume = 13,707 SF x 0.5' Depth = 6,854 CF
Total Watershed Area = 3.1069 AC. = 135,337 SF
CC.STWR CALC.doc
Page 1 of 4

Impervious % = 68,838 SF ; 135,337 SF = 50.9%
Pond Depth = 4.0'
SA/DA % required for 90% solids removal @ 4.0' Depth (see chart)
= 4.4%
4.4% x 135,337 AC. = 5,955 SF
Pond surface area @ Permanent Pool Elev. of 23.2' = 13,302 SF
Pond is therefore adequate for 90% TSS removal.
Orifice Discharge Rate Calculations
Use 1.25" diameter orifice for outlet
'
Calculate average discharge rate and time to lower orifice head from 0.5' to 0.4':
0.1' pond height x 13,707 SF average pond area x 7.5 gal/Ft3
'
= 10,280 Gallons Storage
Average head on orifice from 0.5' to 0.4' = 0.45'
Average discharge rate @ 0.65' head:
GPM = 449 c A 2 h
i'
Q(GPM) =Volume discharged in gallons per minute
c= discharge coefficient = 0.6
A = orifice area in square feet
g = gravity = 32.2
h = head above center of gravity
GPM = 449 .6 .0085 2 32.2 0.45
Q = 12.3 GPM
Time required to lower and 0.1' @ 0.45' average head:
P 9
T = 10,280 Gal. = 12.3 GPM = 836 minutes
12.3 GPM vs 836 minutes plotted on curve (see discharge curve).
CC.STW R CALC.doc Page 2 of 4

Discharge rate and time to lower head from 0.4' to 03:
Q = 10.9 GPM
T = 10,280 Gal. 10.9 GPM = 943 minutes
10.9 GPM vs 1,779 minutes plotted on curve.
Discharge rate and time to lower head from 0.3' to 0.2':
Q=9.2GPM
T = 10,280 Gal. 9.2 GPM = 1,117 minutes
9.2 GPM vs 2,896 minutes plotted on curve.
Discharge rate and time to lower head from 0.2' to 0.1':
Q = 7.1 GPM
T = 10,280 Gal. -= 7.1 GPM = 1,448 minutes
7.1 GPM vs 4,344 minutes plotted on curve.
Discharge rate and time to lower head from 0.1' to 0.0':
Q=4.1GPM
T = 10,280 Gal. _ 4.1 GPM = 2,507inutes
4.1 GPM vs 6,851 minutes plotted on curve.
The outlet structure will discharge the total calculated runoff volume of
51,135 gallons in approximately 4.2 days (see Orifice Discharge Curve).
CC.sTWR CALC.doc
Page 3 of 4

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COUNTRY CLUB VILLAS AT COASTAL CAROLINA COUNTRY CLUB
Forebay Calculations
Provide 20% of Total Permanent Pool volume including area of Forebay
construction:
Permanent Pool Volume:
Pool Area @ Elev. 23.2' = 13,302 SF
Pond Area @ Elev. 19.2' = 5,454 SF
Pond Average Area = 9,378 SF
9,378 SF x 4.0' Depth = 37,512 CF Permanent Pond Volume
Temporary Pool Volume:
13,302 Average Area x 0.5' Depth = 6,651 CF
Permanent Pool Volume = 37,512 CF + 6,651 CF = 44,163 CF
Forebay Volume:
Forebay Area @ Elev. 23.7' = 3,600 SF
Forebay Area @ Elev. 19.2' = 900 SF
Forebay Average Area = 21250 SF
2,250 SF x 4.5' Depth = 10,125 CF Forebay Volume
10,125 CF �- 44,163 CF = 22.9%
Forebay = 22.9% of Total Pond Volume
CC.SfWR CALC.doc
Page 4 of 4

t
SA/DA
- 85%
TSS REMOVAL
WITH 301
VEGETATIVE FILTER
IMPER.%
3-OFT
3.5FT
4-OFT 4.5FT
5.OFT
5.5FT
6.OFT
6.5FT
7.OFT
7.5FT
10%
.9
.8
.7
.6
.5
20%
1.7
1.3
1.2
1.1
1.0
.9
.8
.7
.6
.5
30%
2.5
2.2
1.9
1.8
1.6
1.5
1.3
1.2
1.0
.9
40%
3.4
3.0
2.6
2.4
2.1
1.9
1.6
1.4
1.1
1.0
50%
4.2
3.7
3.3
3.0
2.7
2.4
2.1
1.8
1.5
1.3
60%
5.0
4.5
3.8
3.5
3.2
2.9
2.6
2.3
2.0
1.6
70%
6.0
5.2
4.5
4.1
3.7
3.1
2.9
2.5
2.1
1.8
'
80%
90%
6.8
7.5
6.0
6.5
5.2
5.8
4.7
5.3
4.2
4.8
3.7
4.3
3.2
3.8
2.7
3.3
2.2
2.8
2.0
1.3
100%
8.2
7.4
6.8
6.2
5.6
5.0
4.4
3.8
3.2
2.6
SA/DA
- > 90% TSS
REMOVAL
FOR WET
DETENTION
WITHO
EGETATIVE FILTER
IMPER A
3.OFT
3.5FT
4.OFT
4.5FT
5.OFT
5.5FT
6.0FT
6.5FT
7.OFT
7.5FT
10%
1.3
1.0
.8
.7
.6
.5
.4
.3
.2
.1
20%
2.4
2.0
1.8
1.7
1.5
1.4
1.2
1.0
.9
.6
30%
3.5
3.0
2.7
2.5
2.2
1.9
1.6
1.3
1.1
.8
40%
4.5
4.0
3.5
3.1
2.8
2.5
2.1
1.8
1.4
1.1
50%
5.6
5.0
4.3
3.9
3:5
3.1
2.7
2.3-
1.9
1.5
60%
7.0
30
5.3
4.8
4.3
3.9
3.4
2.9
2.4
1.9
70%
8.1
7.0
6.0
5.5
5.0
4.5
3.9
3.4
2.9
2.3
80%
9.4
8.0
7.O
6.4
5.7
5.2
4.6
4.0
3.4
2.8
90%
10.7
9.0
7.9
7.2
6.5
5.9
5.2
4.6
3.9
3.3
100%
12.0
10.0
8.8
8.1
7.3
6.6
5.8
5.1
4.3
3.6
SAI DA
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COUNTRY CLUB VILLAS at COASTAL CA O A COUNTRY COU CLUB
Sediment Basin Design Calculations
A sediment basin will be used to prevent off -site transportation of sediment
during construction. The sediment basin is designed to function during a 10-year
storm. The Stormwater Detention Pond will serve as sediment basin. 3.25 Acres
1
will be disturbed.
Disturbed Area = 3.25 AC.
'
Basin Dimensions
Area = 13,302 SF
Top of Dam Elev. = 27.0'
Top Weir 23.7
of =
Riser Invert = 22.9'
Orifice Invert — 23.2'
Conduit Pipe = 30" 0
.
Basin Bottom Elev. = 19.2'
Storage Volume Calculations
Provide 0.5 AC -In storage depth per disturbed acre
P
3.25 AC x 0.5 AC -In = 1.6 AC/In
Orifice Invert = 23.2'
Basin Bottom Elev. = 19.2'
Basin Storage Depth = 4.0'
3.25 AC/In = 48" = 0.07 Acres Required Basin Area
QBasin
Dimensions (Actual) = 0.30 Acres
CC.EROS CALC.doc - 7 -

1
1
1
1
Runoff Calculations - Pond Outlet
Use Rational Formula to estimate runoff generated by 100-year event.
Q=CiA
Q = Runoff Volume = ?
C = Runoff Coefficient = 0.50
i = Rainfall Intensity = 8.5 In/Hr.
A = Area = 3.25 Ac.
Q = 0.50 x 8.5 x 3.25
Q = 13.81 CFS
Spillway
Provide 30" 0 conduit pipe at 0.1% slope from sediment basin to ditch as
shown. Provide rip rap at locations shown for energy dissipation. Provide riser
with stormwater dewatering orifice. This outlet structure will retain the total
runoff volume generated by a 100-year storm event and gradually release this
volume over a 2 to 5 day period.
Dam Design
Provide 1' (min.) freeboard above top of riser:
Min. Pond Rim Elev. = 27.0'
Top of Weir = 23.7'
Freeboard = 3.3'
Provide 3:1 side slopes on upstream face of dam and 3:1 side slopes on
downstream face of dam. Provide a minimum top width of 8 feet.
CC.EROS CALC.doc
-8-

5000
400C
3000
200(
100C
80c
60c
50c
40(
30(
20(
101
e+
c 6+
5+
F 4i
Ul
..61 3
V
2
C:
z_
1
C
L
FIGURES 18I
FIGURE 4
FLOW FOR CIRCULAR 01PE FLOWING FULL
BASED ON MANNING'S EQUATION n-0.012
01 .02 .03:04.05 .1 .2 .3 .4.5.6 .8 1. 2 3 4 5 6 B 10
SLOPE OF PIPE IN FEET PER 100 FEET
i
i

Appendices
zv
Iv
8
_
6
O
L
i
4
m
t
U
C
_T
N
C
I
0.8
0.6
0,4
0.
Nnnnnn
Wllmingcnnnnnnnn
,I
10 20 40 60 2 3 4 6 8 IZ 18 24
Minutes Hours
Ouration
Figure 8.03b Rainfall intensity duratian carves—Wiimingtcn.
� \
n
5 IQ 20 40 60 2 3 4 6 8 iZ 18 24
Nlinutes Hours
Duration
Figure 8.03a Painfall intensity curatian curves —Hatteras.
8.035

I
ri
COUNTRY CLUB VILLAS at COASTAL CAROLINA COUNTRY CLUB
Erosion Control Plan
Outlet Protection Design
15" 0 and 18" 0 Pipe Outlets
Use attached Nomographs to determine Rip Rap size and Rip Rap apron
configuration for 18" 0 RCP discharging to detention pond. (4.7 CFS)
Design Criteria:
1. Flow = 4.7 CFS; 18" 0 outlet pipe
2. Assume minimum tailwater conditions; no defined channel.
Pipe Diameter = Do = 1.5'
Apron Length = La = 10' (from Nomograph)
Upstream Apron Width = W, = 3 x Do = 3 x 1.5' = 4.5'
Downstream Apron Width = Do + AL,, = 1.5' + 10' = 11.5' Min.
Median Stone Size = d50 = 0.3' Min (from Nomograph)
(See Attached Rip Rap Blanket Configuration - Plan View)
Select "Class B" Stone (Minimum) 5" - 15"
Apron Thickness = 1.5 x d,,,, = 1.9'
CC.EROS CALC.doc
-9-

Lq = fp
F
`/4% G GF 5
8114-? C/
7.54
3Do
q wa'Dot��.
1 1
Erosion and Sediment Control Handbook
Outlet L is,
pipe { Vtot, 25 tc
diameter Do ,o r�
�J\efi9� °t 9 70
2a \e�g�r
60
15 50
/ 40
O-rO- tl C
20 C., — -
� m Q n '� Hamra
I 12 a i
1.5
1.4
1.3
4 1.2
1.1
3 _ 0.9 g .
I0.8
a }0.7
2.I o.&
a.s a
�5 d' a:0.4
tit d Q o"•.- u i 0.3
1
o
3 5 to 20 50 100 230 Sao tcoo
Discharge, Ft�/sec
0.7 0.2 0.3 0.4 0.6 0.8 t 2 3 4 5 6 7 8 10 15 20 25
Discharge, me/sec
Fig. 7.45 Design of riprap outlet protection from a round pipe lowing full; minimum
tailwater conditions. (6, 14)
to find the riprap size and apron length. The apron width at the pipe end should
be 3 times the pipe diameter. Where there is a well-defined channel immediately
downstream from the apron, the width of the downstream end of the apron
should be equal to the width of the channel. Where there is no well-defined chan-
nel immediately downstream from the apron, minimum tailwater conditions
apply and the width of the downstream end of the apron should be equal to the
pipe diameter plus the length of the apron.
EXAMPLE 7.4 Riprap Outlet Protection Design Calculation for Minimum
Tailwater Condition
Given: A Sow of 6 ft'lsec (0.I7 ml/sec) discharges from a 12•in (30-cm) pipe onto a 2
percent grassy slope with ao defined channel.
Find: The required length, width, and median stone size d5o for a riprap apron.
1 d so = D. 3 ,

I
I
Water Conveyance and Energy Dissipation
7.57
ment. However, to simplify our calculations, we will assume that both i and A remain
constant. Therefore, the postdevelopment runoff is
a.s (0.60.3(20 ft'/sec) = 40 fts/sec 0.3 (0.57 m3/aec) = 1.14 m3/sec
This flow will exceed the natural capacity of the stream. It may erode the streambank
and cause flooding problems.
S'rer 3. Determine how to accommodate the postdeveiopment flow in a nonerosive man-
ner. There are several ways we could handle the increased flow. We could further divide
the subdivision so that approximately one-half drains into the stream and one-half
s
-7 1 o�
{max. TW}
W (min, TWI = Ir. "
Fig. 7.47 Riprap blanket configuration for outlet protec-
tion: see the reference for design details. (2)

COUNTRY CLUB VILLAS at COASTAL CAROLINA COUNTRY CLUB
I
8
1
Erosion Control Plan
Outlet Protection Design
30" 0 Pipe Outlets
Use attached Nomographs to determine Rip Rap size and Rip Rap apron
configuration for 30" 0 pipe outlet to offsite drainage. (Q = 14 CFS)
Design Criteria:
1. 30" 0 RCP outlet pipe with 14 CFS discharge.
2. Assume maximum tailwater conditions; well-defined channel.
Pipe Diameter = Do = 2.5'
Apron Length = La = 12' (from Nomograph)
Upstream Apron Width = W„ = 3 x Do = 3 x 2.5' = 7.5'
Downstream Apron Width = Do + AlLa = 2.5' + 4.8' = 7.3' Min.
Median Stone Size = d50 = 0.2' Min (from Nomograph)
(See Attached Rip Rap Blanket Configuration - Plan View)
Select "Class B" Stone (Minimum) 5" - 15"
Apron Thickness = 1.5 x d,,ax = 22.5"
CC.EROS CALC.doc
-10-

1
1
1
1
1
1
1
1
'1
1
1
1
1
1
1
1
1
1
i
4q 7-/ L
Water Conveyance and Energy Dissipation 7.55
I30,
Outiet } T
pioe 5 1 Wa 0a+0.41.,
diameter }
Do h— �, --} 120
35
110
R
k% 100
90
G�
\��or 25 soya 80
A
�4F
20 �F
60
t5 50
N co
` T ry �o f�'? ,rv�u�' �aM� 1IIi 3 0.9
10 30
5—z a 2 m
10 = 0.5 .N
4 I
0.4 ro
—�,,0.3 .�
To.z d o ! o, Z-r
o a TO-1 S
3 5 10 20 50 100 200 500 1000
Oischarge,ft3/sec
.1 .2 .3 4.5.6.7.3.91 2 3 4 557810 15 2025
Discharge, m3lsec
Fig. -4.46 Design of riprap outlet protection from a round pipe Bowing full; maximum
tailwater conditions. (6, 14)
Solutions Since the pipe discharges onto a flat area with no defined channel, a mini-
mum tailwater condition%b n be assumed.
By Fig. 1.45, the apron length L, and median stone size d5a are 10 ft (3 m) and 0.3 ft
(9 cm), respectively. The Upstream apron width W equals 3 times the pipe diameter D,:
W,=3XD,
3(1 ft)'= aft (3(0.3 m) = 0.9 m)
The downstream apron width Wd equals the apron length plus the pipe diameter:
Wd=D,-L,
=1ft+10ft=lift (0.3 m + 3.0 m = 3.3 m)
Note: When a concentrated flow is discharged onto a slope (as in this example), gul-
lying can occur downhill from the outlet protection. The spreading of concentrated Sow
30 "0 )Z C" 0ii " i

Water Conveyance and Energy Dissipation
7.57
meat. However, to simplify our calculations, we will assume that both i and A remain
constant. Therefore, the postdevelopment runoff is0.6
11
0.3 (20 felsec) - 40 ft�/sec (Q 3 (0.57 m'/sec) a 1.14 m3/sec1
This flow will exceed the natural capacity of the stream. It may erode the streambank
and cause flooding problems.
STEP 3. Determine how to accommodate the postdevelopment flow ins nonerosive man-
ner. 'There are several ways we could handle the increased flow. We could further divide
the subdivision so that approximately one-half drains into the stream and one-half
0, zz.s'
r--- 30, c 7. S
Fig. 7.47 Riprap blanket configuration for outlet protec-
tion; see the reference for design details. (2)
30""0 1ZGP oUTLET F,z. m 54D1417Ez-r Patin
i

TRAPEZOIDAL. CHANNEL ANALYSIS
RATING CURVE COMPUTATION
March 11, 1999
PROGRAM INPUT DATA
DESCRIPTION
-------------------------------------------------------------------------
Channel Bottom Slope(ft/ft) ................................
_-++VALUE
0.001
Manning'n Roughness Coefficient {n-value)...................
0.03
Channel Left Side Slope (horizontal/vertical)...............
5.0
Channel Right Side Slope (horizontal/vertical)..............
5.0
Channel Bottom Width(ft)...................................
2.0
Minimum Flow Depth(ft)................................
0.1
Maximum Flow Depth (ft). ...............................I....
5.1
Incremental Head(ft).......................................
0.1
�1'1 ����a �v»SS�CS Q.�-JSW�•_���C��^J
�-J� 1�3�3.r�C.
3��CC�Q4C�-__�_�J.^.C������i�IIOC--��O
COMPUTATION
RESULTS
Flow
Flow
Flow
Froude
Velocity
Energy
Flow
Top
Depth
Rate
velocity
Number
Head
Head
Area
Width
(ft)
--------
(cfs)
(fps)
(ft)
--.
(ft)
(sq ft)
(ft)
0.1
0.07
0.3
0.182
0.001
0.101
0.25
3.0
0.2
0.26
0.44
0.2
0.003
0.203
0.6
4.0
0.3
0.58
0.55
0.211
0.005
0.305
1.05
5.0
0.4
1.03
0.64
0.22
0.006
0.406
1.6
6.0
0.5
1.64
0.73
0.226
0.008
0.508
2.25
7.0
0.5
2.42
0.81
0.232
0.01
0.61
3.0
8.0
'
0.7
3.39
0.88
0.237
0.012
0.712
3.85
9.0
0.3
4.56
0.95
0.242
0.014
0.814
4.8
10.0
0.9
3-95
1.02
0.246
0.016
0.916
5.85
11.0
1.0
7.57
1.08
0.25
0.018
1.018
7.0
12.0
1.1
9.44
1.14
0.253
0.02
1.12
8.25
13.0
1.2
11.56
1.2
0.256
0.023
1.223
_9.6
14.0
1.26
0.259
0.025
1.325
11.05
15.0
1.4
16.64
1.32
0.262�
0.027
1.427
12.6
16.0
1.5
19.61
1.38
0.265
0.029
1.529
14.25
17.0
1.6
22.9
1.43
0.268
0.032
1.632
16.0
18.0
1.7
26.51
1.48
0.27
0.034
1.734
17.85
19.0
1.8
30.44
1.54
0.272
0.037
1.837
19.8
20.0
'
1.9
34.73
1.59
0.275
0.039
1.939
21.85
21.0
2.0
39.37
1.64
0.277
0.042
2.042
24.0
22.0
2.1
44.37
1.69
0.279
0.044
2.144
26.25
23.0
2.2
19.75
1.74
0.211
0.047
2.247
28.6
14.0
2.3
55.52
1.79
0.283
0.05
2.35
31.05
25.0
2.4
61.69
1.84
0.285
0.052
2.452
33.6
26.0
2.5
69.27
1.88
0.287
0.055
2.555
36.25
27.0
2'.6
75,27
1.93
0.288
0.058
2.658
39.0
28.0
2.7
82.69
1.98
0.29
0.061
2.761
41.85
29.0
2.8
90.56
2.02
0.292
0.064
2.864
44.8
30.0
2.9
98.88
2.07
0.293
0.066
2.966
47.85
31.0
'
3.0
3.1
107.66
116.91
2.11
2.16
0.295
0.296
0.069
0.072
3.069
3.172
51.0
54.25
32.0
33.0
3.2
126.64
2.2
0.298
0.075
3.275
57.6
34.0
3.3
136.86
2.24
0.299
0.078
3.378
61.05
35.0
3.4
3.5
147.58
158.81
2.28
2.33
0.301
0.302
0.081
0.084
3.481
3.584
64.6
68.25
36.0
37.0
3.6
170.55
2.37
0.303
0.087
3.687
72.0
38.0
3.7
182.82
2.41
0.305
0.09
3.79
75.85
39.0
'
3.8
3.9
195.63
208.99
2.45
2.49
0.306
0.307
0.093
0.097
3.893
3.997
79.8
83.85
40.0
41.0
4.0
222.9
2.53
0.308
0.1
4.1
88.0
42.0
4.1
237.37
2.57
0.31
0.103
4.203
92.25
43.0
4.2
4.3
252.41
268.04
2.61
2.65
0,311
0.312
0.106
0.109
4.306
4.409
96.6
101.05
44.0
45.0
4.4
284.26
2.69
0.313
0.113
4.513
105.6
46.0
CouA17'j,Y CL02
VILL45
L)(Z61 ✓/�GF
FROG 5r0RM r//,
POIV D r

'
4.5
301.07
2.73
0.314
0.116
4.616
110.25
47.0
4.6
318.49
2.77
0.315
0.119
4.719
115.0
48.0
4.7
336.53
2.81
0.317
0.123
4.823
119.85
49.0
4.8
355.19
2'.85
0.318
0.126
4.926
124.8
50.0
4.9
374.49
2.88
0.319
0.129
5.029
129.85
51.0
5.0
394.43
2.92
0.32
0.133
5.133
135.0
52.0
5.1
415.01
2.91
0.321
0.131
140.25
53.0
'
�5.231
=ROCALC
Hydraulics
for windows,
version
1.2a Copyright (c)
1996
Oodson & Associates,
Inc,, 5129 I'll 1960 West, Suite
314, Houston, TX 77169
'
Phone:[phone],
Fax:[phone],
[e-mail]
All Rights
Reserved.

TRAPEZOIDAL CFDINNEL ANALYSIS
RATING CURVE COMPUTATION
1
11
a
I
March 11, 1999
�-=c�maa3�caa=m;aa=asa=====a==aaax=�=a;saa�a=sa-a�aa==vc=-••.•^-====ca-aa� -==a.=
PROGRAM INPUT DATA
DESCRIPTION VALUE
--------------------------------------------------------------------------------
Channel Bottom Slope(ft/ft)................................ 0.001
Manning's Roughness Coefficient (n-value)................... 0.03
Channel Left Side Slope (horizontal/vertical)............... 3.0
Channel Right Side Slope (horizontal/vertical).............. 3.0
Channel Bottom Width(ft)................................... 2.0
Minimum Flow Depth(ft)..................................... 0.1
Maximum Flow Depth (ft). 4.6
Incremental head(ft)....................................... 0.1
CovalT?IU CL U
COMPUTATION RESULTS
Flow
Flow
Flow
Froude
Velocity
Energy
Flow
Top 5 W 4LE5 / i
Depth
Rate
Velocity
Number
Head
Head
Area
Width f24#jZ 4p/p 51pE5
(ft)
(cfs)
(fps)
(ft)
(ft)
(sa ft)
(ft) or- gvr`D?NCr-S
0.1
0.07
0.31
0.183
0.001
0.101
0.23
2.6
0.2
0.24
0.46
0.201
0.003
0.203
0.52
3.2
0.3
0.5
0.58
0.212
0.005
0.305
0.87
3.8
0.4
0.86
0.67
0.22
0.007
0.407
1.28
4.4
0.5
1.33
0.76 _
0.227
0.409
0,509
1.75
5.0
0.6
1.92
0.34
0.232
0.011
0.6i1
2.23
5.6
0.7
2.63
0.92
0.237
0.013
0.713
2.87
6.2
0.8
3.47
0.98
0.241
0.015
0.815
3.52
6.8
0.9
4.45
1.05
0.245
0.017
0.917
4.23
7.4
1.0
5.58
1.12
0.249
0.019
1.019
5.0
8.0
1.1
6.86
1.18
0.252
0.022
1.122
5.83
8.6
1.2
8.3
1.24
0.255
0.024
1.224
6.72
9.2
1.3
9.92
1.29
0.258
0.026
1.326
7.67
9.8
1.4
I1.71
1.35
0.26
0.028
1.428
8.63
10.4
1.5
13.69
1.4
0.263
0.031
1.531
9.75
11.0
1.6
15.86
1.46
0.265
0.033
1.633
10.88
11.6
1.7
18.23
1.51
0.268
0.035
1.735
12.07
12.2
1.8
20.8
1.56
0.27
0.038
1.838
13.32
12.8
1.9
23.58
1.61
0.272
0.04
1.94
14.63
13.4
2.0
26.58
1.66
0.274
0.043
2.043
16.0
14.0
2.1
29.8
1.71
0.276
0.045
2.145
17.43
14.6
2.2
33.26
1.76
0.278
0.048
2.248
18.92
15.2
2.3
36.95
1.81
0.28
0.051
2.351
20.47
15.8
2.4
40.86
1.85
0.281
0.053
2.453
22.08
16.4
2.5
45.07
1.9
0.283
0.056
2.556
23.75
17.0
2.6
49.5
1.94
0.285
0.059
2.659
25.48
17.6
2.7
54.2
1.99
0.286
0.061
2.761
27.27
18.2
2.8
59.17
2.03
0.288
0.064
2.864
29.12
18.8
2.9
64.41
2.08
0.289
0.067
2.967
31.03
19.4
3.0
69.92
2.12
0.291
0.07
3.07
33.0
20.0
3.1
75.72
2.16
0.292
0.073
3.173
35.03
20.6
3.2
81.81
2.2
0.294
0.075
3.275
37.12
21.2
3.3
68.2
2.25
0.295
0.078
3.378
39.27
21.8
3.4
94.88
2.29
0.296
0.081
3.481
41.48
22.4
3.5
101.87
2.33
0.298
0.084
3.584
43.75
23.0
3.6•
109.18
2.31
0.299
0.087
3.687
46.08
23.6
3.7
116.8
2.41
0.3
0.09
3.79
48.47
24.2
3.8
124.74
2.45
0.301
0.093
3.993
50.92
24.8
3.9
133.01
2.49
0.303
0.096
3.996
53.43
25.4
4.0
141.61
2.53
0-304
0.099
4.099
56.0
26.0
4.1
150.55
2.57
0.305
0.102
4.202
58.63
26.6
4.2
159.84
2.61
0.306
0.106
4.306
61.32
27.2
4.3
169.47
2.65
0.307
0.109
4.409
64.07
27.8
4.4
179.45
2.68
0.308
0.112
4.512
66.88
28.4
0

4.5 189.8 2.72 0.309 0.115 4.615 69.75 29.0
4.6 200.5 2.76 0.31 0.118 4.718 72.68 29.6
s«azaa���as:a=�em�mx ��^�---�� �—��� gss�=�------•��apa—•-•--�fl-------m�ava�a�aaaa
HYDROCALC Hydraulics for Windows, Version 1.2a Copyright (c) 1996
Dodson 4 Associates, Inc., 5629 FM 1960 West, suite 314, Houston, TX 77069
Phone: [phone], Fax: [phone], Email:[e-mail]
ALI. Rights Reserved.