SW8070420_HISTORICAL FILE_20070709 (2)

STORMWATER DIVISION CODING SHEET
POST -CONSTRUCTION PERMITS
PERMIT NO.
SW8 d"1 QLy 20
DOC TYPE
❑ CURRENT PERMIT
❑ APPROVED PLANS
HISTORICAL FILE
❑ COMPLIANCE EVALUATION INSPECTION
DOC DATE
l o n-� O-1 0
YYYYMMDD
i

�;. FWATF
* � i� Michael P. Easley, Governor
William G. Ross Jr, Secretary
> r r North Carolina Department of Environment and Natural Resources
O ®Y Colcen H. Sullins Director
Division of Water Quality
July 9, 2007
W. K. Morgan, Sr.
122 Drayton Hall
Jacksonville, NC 28540
Subject: Stormwater Permit No. SW8 070420
Shopping & Office Park - Holly Ridge, NC
High Density Project
Onslow County
Dear Mr. Morgan:
The Wilmington Regional Office received a complete Stormwater Management Permit
Application for Shopping & Office Park - Holly Ridge, NC on April 20, 2007. Staff review of the
plans and specifications has determined that the project, as proposed, will comply with the
Stormwater Regulations set forth in Title 15A NCAC 2H.1000. We are forwarding Permit No.
SW8 070420 dated July 9, 2007, for the construction of the subject project.
This permit shall be effective from the date of issuance until July 9, 2017, and shall be subject
to the conditions and limitations as specified therein. Please pay special attention to the
Operation and Maintenance. requirements in this permit. Failure to establish an adequate
system for operation and maintenance of the stormwater management system will result in
future compliance problems.
If any parts, requirements, or limitations contained in this permit are unacceptable, you have
the right to request an adjudicatory hearing upon written request within sixty (60) days -
following receipt of this permit. This request must be in the form of a written petition,
conforming to Chapter 150E of the North Carolina General Statutes, and filed with the Office of
Administrative Hearings, P.O. Drawer 27447, Raleigh, NC 27611-7447. Unless such demands
are made this permit shall be final and binding.
If you have any questions, or need additional information concerning this matter, please
contact Rhonda Hall, or me at [phone].
Sincer6ly,
Edward Beck
Regional Supervisor
Surface Water Protection Section
ENB/rbh: S:\WQS\STORMWATER\PERMIT\070420.ju107
cc: David K. Newsom, PE, Crystal Coast Engineering, PA
Onslow County Building Inspections
Rhonda Hall
Wilmington Regional Office
Central Files
North Carolina Division of Water Quality 127 Cardinal Drive Extension Wilmington, NC 28,105 Phone [phone]
Wilmington Regional Office Internet: w .ncwatcroualitv.ore Fax [phone]
NoilhCarolina
An71=/!U
Customer Service
1-877-623-6748
An Equal Opportunity/Affirmative Action Employer — 50% Recycled/1 0% Post Consumer Paper

State Stormwater Management Systems
Permit No. SW8 070420
STATE OF NORTH CAROLINA
DEPARTMENT OF ENVIRONMENT AND NATURAL RESOURCES
DIVISION OF WATER QUALITY
STATE STORMWATER MANAGEMENT PERMIT
HIGH DENSITY DEVELOPMENT
In accordance with the provisions of Article 21 of Chapter 143, General Statutes of
North Carolina as amended, and other applicable Laws, Rules, and Regulations
PERMISSION IS HEREBY GRANTED TO
W. K. Morgan, Sr.
Shopping & Office Park - Holly Ridge, NC
Onslow County
FOR THE
construction, operation and maintenance of a wet detention pond in compliance with
the provisions of 15A NCAC 2H .1000 (hereafter referred to as the "stormwater rules')
and the approved stormwater management plans and specifications and other
supporting data as attached and on file with and approved by the Division of Water
Quality and considered a part of this permit.
This permit shall be effective from the date of issuance until July 9, 2017, and shall be
subject to the following specified conditions and limitations:
I. DESIGN STANDARDS
This permit is effective only with respect to the nature and volume of stormwater
described in the application and other supporting data.
2. This stormwater system has been approved for the management of stormwater
runoff as described in Section 1.6 on page 3 of this permit. The stormwater
control has been designed to handle the runoff from 337,097 square feet of
impervious area.
3. The tract will be limited to the amount of built -upon area indicated on page 3 of
this permit, and per approved plans. The built -upon area for the future
development is limited to 8,216 square feet.
4. All stormwater collection and treatment systems must be located in either
dedicated common areas or recorded easements. The final plats for the project
will be recorded showing all such required easements, in accordance with the
approved plans.
5. The runoff from all built -upon area within the permitted drainage area of this
project must be directed into the permitted stormwater control system.
Page 2 of 7

State Stormwater Management Systems
Permit No. SW8 070420
6. The following design criteria have been provided in the wet detention pond and
must
be maintained at design condition:
a.
Drainage Area, acres:
12.66
Onsite, ft :
551,648
Offsite, ft2:
None
b.
Total Impervious Surfaces, ft2:
337,097
C.
Design Storm, inches:
1
d.
Pond Depth, feet:
6
e.
TSS removal efficiency:
90%
f.
Permanent Pool Elevation, FMSL:
48.00
g.
Permanent Pool Surface Area, ft2:
20,024
h.
Permitted Storage Volume, ft3:
41,016
i.
Temporary Storage Elevation, FMSL:
49.88
j.
Controlling Orifice:
2.00" 0 pipe
k.
Permitted Forebay Volume, ft3:
15,140
I.
Fountain Horsepower, HP
1/4
M.
Receiving Stream/River Basin:
UT King Creek / Cape Fear
n.
Stream Index Number:
18-87-4
o.
Classification of Water Body:
"SC, Sw, HQW"
II. SCHEDULE OF COMPLIANCE
1. The stormwater management system shall be constructed in its entirety,
vegetated and operational for its intended use prior to the construction of any
built -upon surface.
2. During construction, erosion shall be kept to a minimum and any eroded areas of
the system will be repaired immediately.
3. The permittee shall at all time provide the operation and maintenance necessary
to assure the permitted stormwater system functions at optimum efficiency. The
approved Operation and Maintenance Plan must be followed in its entirety and
maintenance must occur at the scheduled intervals including, but not limited to:
a. Semiannual scheduled inspections (every 6 months).
b. Sediment removal.
C. Mowin.9 and re -vegetation of slopes and the vegetated filter.
d. Immediate repair of eroded areas.
e. Maintenance of all slopes in accordance with approved plans and
specifications.
f. Debris removal and unclogging of outlet structure, orifice device, flow
spreader, catch basins and piping.
g. Access to the outlet structure must be available at all times.
Page 3 of 7

State Stormwater Management Systems
Permit No. SW8 070420
4. Records of maintenance activities must be kept and made available upon
request to authorized personnel of DWQ. The records will indicate the date,
activity, name of person performing the work and what actions were taken.
5. Decorative spray fountains will be allowed in the stormwater treatment system,
subject to the following criteria:
a. The fountain must draw its water from less than 2' below the permanent
pool surface.
b. Separated units, where the nozzle, pump and intake are connected by
tubing, may be used only if they draw water from the surface in the
deepest part of the pond.
c. The falling water from the fountain must be centered in the pond, away
from the shoreline.
d. The maximum horsepower for a fountain in this pond is 1/4 horsepower.
6. The facilities shall be constructed as shown on the approved plans. This permit
shall become void unless the facilities are constructed in accordance with the
conditions of this permit, the approved plans and specifications, and other
supporting data.
Upon completion of construction, prior to issuance of a Certificate of Occupancy,
and prior to operation of this permitted facility, a certification must be received
from an appropriate designer for the system installed certifying that the permitted
facility has been installed in accordance with this permit, the approved plans and
specifications, and other supporting documentation. Any deviations from the
approved plans and specifications must be noted on the Certification. A
modification may be required for those deviations.
8. If the stormwater system was used as an Erosion Control device, it must be
restored to design condition prior to operation as a stormwater treatment device,
and prior to occupancy of the facility.
9. Access to the stormwater facilities shall be maintained via appropriate
easements at all times.
10. The permittee shall submit to the Director and shall have received approval for
revised plans, specifications, and calculations prior to construction, for any
modification to the approved plans, including, but not limited to, those listed
below:
a. Any revision to any item shown on the approved plans, including the
stormwater management measures, built -upon area, details, etc.
b. Project name change.
C. Transfer of ownership.
d. Redesign or addition to the approved amount of built -upon area or to the
drainage area.
e. Further subdivision, acquisition, lease or sale of all or part of the project
area. The project area is defined as all property owned by the permittee,
for which Sedimentation and Erosion Control Plan approval or a CAMA
Major permit was sought.
f. Filling in, altering, or piping of any vegetative conveyance shown on the
approved plan.
11. The permittee shall submit final site layout and grading plans for any permitted
future areas shown on the approved plans, prior to construction.
12. A copy of the approved, plans and specifications shall be maintained on file by
the Permittee for a minimum of ten years from the date of the completion of
construction.
Page 4 of 7

State Stormwater Management Systems
Permit No. SW8 070420
13. The Director may notify the permittee when the permitted site does not meet one
or more of the minimum requirements of the permit. Within the time frame
specified in the notice, the permittee shall submit a written time schedule to the
Director for modifying the site to meet minimum requirements. The permittee
shall provide copies of revised plans and certification in writing to the Director
that the changes have been made.
III. GENERAL CONDITIONS
1
1. This permit is not transferable except after notice to and approval by the Director.
In the event of a change of ownership, or a name change, the permittee must
submit a formal permit transfer request to the Division of Water Quality,
accompanied by a completed name/ownership change form, documentation
from the parties involved, and other supporting materials as may be appropriate.
The approval of this request will be considered on its merits and may or may not
be approved. The permittee is responsible for compliance with all permit
conditions until such time as the Division approves the transfer request.
Failure to abide by the conditions and limitations contained in this permit may
subject the Permittee to enforcement action by the Division of Water Quality, in
accordance with North Carolina General Statute 143-215.6A to 143-215.6C.
3. The issuance of this permit does not preclude the Permittee from complying with
any and all statutes, rules, regulations, or ordinances, which may be imposed by
other government agencies (local, state, and federal) having jurisdiction.
4. In the event that the facilities fail to perform satisfactorily, including the creation
of nuisance conditions, the Permittee shall take immediate corrective action,
including those as may be required by this Division, such as the construction of
additional or replacement stormwater management systems.
5. The permittee grants DENR Staff permission to enter the property during normal
business hours for the purpose of inspecting all components of the permitted
stormwater management facility.
6. The permit may be modified, revoked and reissued or terminated for cause. The
filing of a request for a permit modification, revocation and re -issuance or
termination does not stay any permit condition.
7. Unless specified elsewhere, permanent seeding requirements for the stormwater
control must follow the guidelines established in the North Carolina Erosion and
Sediment Control Planning and Design Manual.
8. Approved plans and specifications for this project are incorporated by reference
and are enforceable parts of the permit.
9. The permittee shall notify the Division any name, ownership or mailing address
changes within 30 days.
Permit issued this the 9t' day of July, 2007.
NORT AROLINA VIRONMENTAL MANAGEMENT COMMISSION
for Coleen H. Sullins, Director
Division of Water Quality
By Authority of the Environmental Management Commission
Page 5 of 7

OFFICE USE ONLY
—Date Received
Fee Paid
Permit Num er
� 0 200
qZD.00I
5w FD 70'VaO
State of North Carolina .
Department of Environment and Natural Resources
Division of Water Quality
STORMWATER MANAGEMENT PERMIT APPLICATION FORM
This form mar he photocopied for use as an original
GENERAL INFORMATION
1. Applicants name (specify the name of the corporation, individual, etc. who owns the project):
W. IC. (n Urgan,jsr- .
2. Print Owner/Signing Official's name and title (person legally responsible for facility and compliance):
6rs� ctnnciIVIdttal
3. Mailing Address for person listed in item 2 above:
City: :lac Ksr, S Ut ilk State: NC Zip: A3 51 I D
Telephone Number: ( q 11) ) 3g -7 —1 305
4. Project Name (subdivision, facility, or establishment name - should be consistent with project name on plans,
specifications, letters, operation and maintenance agreements, etc.):
Shopping & Office Park - Holly Ridge, NC
5. Location of Project (street address):
US Hwy 17
City: Stump Sound Township County: Onslow
6. Directions to project (from nearest major intersection):
From the intersection of NC 50 and US 17, northeast on US 17 approximately 0.8 miles. Site on right. (Between
Crawford St. and Hines Stump Sound Church Rd.)
7. Latitude: 340 30' 10" N Longitude: 77' 32' 37" W
8. Contact person who can answer questions about the project:
Name: David K. Newsom, PE, Crystal Coast Engineering, PA Telephone Number:
II, PERMIT INFORMATION:
1. Specify whether project is (check one): X New Renewal
Form SWU-101 Version 3.99 Page I of
of project
L1Liitcy���IIPL�
Modification

2r If this application is being submitted as the result of a renewal or modification to an existing permit, list the
existing permit number nla and its issue date (if known)
3. Specify the type of project (check one):
_Low Density X High Density _Redevelop _General Permit _Other
4. Additional Project Requirements (check applicable blanks):
_CAMA Major X Sedimentation /Erosion Control 404/401 Permit NPDES Stormwater
Information on required state permits can be obtained by contacting the Customer Service Center at
1-877-623-6748.
Ill. PROJECT INFORMATION
1. In the space provided below. summarize how stormwater will be treated. Also attach a detailed narrative
(one to two pages) describing stormwater management for the project.
- Stormwater will be collected and treated in a wet detention basin.
2. Stormwater runoff from this project drains to the Cape Fear River basin.
3. Total Project Area: 16.98 acres 4. Project Built Upon Area: 45.58
5. How many drainage areas does the project have? I
6. Complete the following information for each drainage area. If there are more than two drainage areas in the
project, attach an additional sheet with the infonnation for each area provided in the same format as below.
Basin Information
Drainage Area 1
Drainage Area 2,
Receiving Stream Name
UT Kings Creek
Receiving Stream Class
SC; Sw HOW
Drainage Area
551,648 sf
Existing Impervious* Area
_0_
Proposed Impervious*Area
337,097 sf
% Impervious* Area (total)
61.1 %
Impervious*.Sd'rface Area
Drainage Area 1
Drainage Area 2
On -site Buildings
100,283 sf
On -site Streets
0_
On -site Parking
206,367 sf
On -site Sidewalks
20,641 sf
Other on -site (water tower)
1,590 sf
Off -site (future reserve)
8,216 sf
Total: 337,097 sf (7.74 ac)
Total:
* Impervious area is defined as the built upon area including, but not limited to, buildings, roads, parking areas,
sidewalks, gravel areas, etc.
Form SWU-101 Version 3.99 Page 2 of 4

How was the off -site impervious area listed above derived? n/a
IV. DEED RESTRICTIONS AND PROTECTIVE COVENANTS
The following italicized deed restrictions and protective covenants are required to be recorded for all
subdivisions, outparcels and future development prior to the sale of any lot. If lot sizes vary significantly, a table
listing each lot number, size and the allowable built -upon area for each lot must be provided as an attachment.
The following covenants are intended to ensure ongoing compliance with state stornnvater management permit number
as issued by the Division of IYater Quality. These covenants may not be
clanged or deleted without the consent of the State.
2..No more than square feet of mnY lot shall be covered by structures or impervious materials.
Impervious materials include asphalt, gravel, concrete, brick, stone, slate or similar material but do not include wood
decking or the water sun lace of swimming pools.
3. Sit -ales shall not be filled in, piped, or altered except as necessary to provide driveway crossings.
4. Built -upon area in excess of the permited amount requires a state stormwater management permit modification prior to
construction.
5. All permitted runofffrom outparcels or future development shall be directed into the permitted stornnvater control
system. These connections to the stormwater control system shall be performed in a manner that maintains the integrity
and performance of the system as permitted.
By your signature below, you certify that the recorded deed restrictions and protective covenants for this project
shall include all the applicable items required above, that the covenants will be binding on all parties and persons
claiming under them, that they will run with the land, that the required covenants cannot be changed or deleted
without concurrence from the State, and that they will be recorded prior to the sale of any lot.
V. SUPPLEMENT FORMS
The applicable state stormwater management permit supplement form(s) listed below must be submitted for each
BMP specified for this project. Contact the Storinwater and General Permits Unit at [phone] for the status
and availability of these forms.
Form SWU-102
Wet Detention Basin Supplement
Form SWU-103
Infiltration Basin Supplement
Form SWU-104
Low Density Supplement
Form SWU-105
Curb Outlet System Supplement
Form SWU-106
Off -Site System Supplement
Form SWU-107
Underground Infiltration Trench Supplement
Form SWU-108
Neuse River Basin Supplement
Form SWU-109
Innovative Best Management Practice Supplement
Form SWU-101 Version 3.99 Page 3 of 4

VT., SUBMITTAL REQUIREMENTS
Only complete application packages will be accepted and reviewed by the Division of Water Quality (DWQ).
A complete package includes all of the items listed below. The complete application package should be
submitted to the appropriate DWQ Regional Office.
1. Please indicate that you have provided the following required information by initialing in the space provided
next to each item
i ials
• Original and one copy of the Stormwater Management Permit Application Form
• One copy of the applicable Supplement Form(s) for each BMP r
• Permit application processing fee of $420 (payable to NCDENR)
• Detailed narrative description of stormwater treahment/management
• Two copies of plans and specifications, including: 1 ,
- Development/Project name
- Engineer and firm
-Legend
- North arrow
- Scale
- Revision number & date
- Mean high water line
- Dimensioned property/project boundary
- Location map with named streets or NCSR numbers
- Original contours, proposed contours, spot elevations, finished floor elevations
- Details of roads, drainage features, collection systems. and stormwater control measures
- Wetlands delineated, or a note on plans that none exist
- Existing drainage (including off -site), drainage easements, pipe sizes, runoff calculations
- Drainage areas delineated
- Vegetated buffers (where required)
V11. AGENT AUTHORIZATION
If you wish to designate authority to another individual or firm so that they may provide information on your
behalf, please complete this section.
Designated agent (individual or firm): David K. Newsom, PE, Crystal Coast Engineering, PA
Mailing Address:3817-3 Freedom Way
City: Hubert State: N.C. Zip:28539
Phone: [ 910 ) 325-0006 Fax: ( 910 ) 325-0060
VIII, APPLICANT'S CERTIFICATION
I, (print or type name of person listed in General Information, item 2) �). , l t / o r9 o_t S r.—„
certify that the information included on this permit application form is, to the best of my knowledge, correct and
that the project will be constructed in conformance with the approved plans, that the required deed restrictions
and protective covenants will be recorded, and that the proposed project complies with the requirements of 15A
NCAC 21-1.1000.
Fonn SVU-101 Version 3.99
Page 4 of 4
Date:

3817-3 Freedom Way
Hubert, N.C. 28539
Tel: [phone] i
Fax: [phone]
5 14�).F0 7D V ,;t- O
Transn*W
To: Linda Lewis
NC Division of Water Quality
127 Cardinal Drive Ext.
Wilmington, NC 28405
Re Shopping & Office Park — Holly Ridge
❑ Urgent
Attached:
From: Jeanie Clinkinbeard
Date: April 19, 2007
❑ For Review ❑ Please Comment ❑ Please Reply ❑ Please Recycle
One (1) original and One (1) copy Stormwater Permit Application
One (1) Wet Detention Basin Supplement
One (1) copy Design Calculations
One (1) copy Narrative
One (1) USGS location map
One (1) check in the amount of $420
Two (2) sets plans
Comments:
Submitted for review and, if acceptable, approval.
REl CE hD
aROJ #
APR 2, 0 2007
DWQ

I
Design Calculations
Stormwater Treatment Facilities
for
Shopping & Office Park - Holly Ridge
located in
Onslow County
1. PROJECT DESCRIPTION
R' 357
The Project consists of proposed businesses on a 16.98 acre tract and associated sitework.
2. COMPUTE POND AREA REQUIRED
a. Compute Percent Impervious:
Impervious Areas
On -Site Buildings
On -Site Streets
On -Site Parking
On -Site Sidewalks
Other on -site
Off -site
Sub -Total
FUTURE
FUTURE(reserved)
Tota I
Total Area Drainage to Pond:
Percent Impervious -
b. Compute Pond Surface Area
0 0
........... 0 0
0 0
Total
100,283 SF
0 SF
206,367 SF
20,641 SF
1,590
0
328,881 SF
8216
0 SF
337,097 SF
.... .....
x.
551,648 SF
Using Surface Area to Drainage Area Ratio Chart for 90% TSS Removal (copy attached) and
assuming 'foot pond depth:
M
SA/DA (interpolated)
Therefore:
Surface Area = SA/DA x Drainage Area
19,062 SF say SF

c. Compute Minimum Pond Dimensions
Assume rectangular shape with 3:1 Length (L) to Width (W) Ratio:
Length = 245.10 feet
Width = 81.70 feet
Site conditions, however, dictate irregular shaped pond:
Hydr. Length — ..... 4.5,11 feet
so, Hydr. Width 81.7 feet (avg)
Actual L/W = 3.0 (irregular shape)
3. DETERMINE VOLUME TO BE CONTROLLED FROM 1.0" STORM
Using Schuler "Simple Method":
Rv = 0.05 + 0.009(I) where I = percent impervious
Rv = 0.600 in/in
Control Volume = Design Rainfall x Rv x Drainage Area
Control Volume = 27,581 CF
4. DETERMINE REQUIRED STORAGE DEPTH
Assume: 3:1 side slopes
solving for depth (d) by trial $ error:
d = 1.88
5. DETERMINE ORIFICE SIZE
say $1 t118 CF
Control Volume must be drawn down over a 2 day - 5 day period.
Using orifice equation, solve for Diameter (D) that results in 3-1/2 day period:
D = (Q / 0.026 (h) e).s
Where: Q = (Control Volume / 3.5 days x 86,400 sec/day)
= 0.136 cfs
h=d/2
= 0.94
Solving for D:

D = 2.32 Use" Pipe
Actual Drawdown with actual drawdown pipe diam 2.00
Q= 0.101 cfs
Draw Down Period = 4.71 days OK, < 5.0
6. SELECT OUTLET STRUCTURE DIAMETER
Size outlet structure such that depth of Q10 flow <1.0 feet:
Using Rational Formula (Q=CIA) where:
CimperCpery
.
Ccum = .......:.....:.:0.57
..............................
.............................
110 = 3 'tS'€' €- 7 ^i7 in/hr
A .,::... 12.66 a c
Q 10 = 51.45 cfs
Assuming 1/2 circumference is used as weir and using
Francis Formula (Q=3.33LH"5) to solve for L such that H = 1.0:
L = 15.45 Feet
Min 60 inch diameter outlet structure
Use 60 inch diameter outlet structure
7. DETERMINE Q10 STAGE
Q10 = 51.45 cfs
Using Francis Formula (Q=3.33LH"'y solve for H:
H10 = 1.57 feet
8. DETERMINE Q100 STAGE (ELEV. OF EMERGENCY SPILLWAY)
Using Rational Formula (Q=CIA) where:
Ccum = 0.57
1100 5in/hr
A = 12.66 ac
Q100 = 61.00
Using Francis Formula (0=3.33LH"5) solve for H:
H 100 = 1.76 feet

9. DETERMINE Q100 STAGE OVER EMERGENCY SPILLWAY (TOP BERM ELEV.)
Assume primary spillway blocked (i.e., emergency spillway to accommodate Q100)
Emergency spillway shall be a broad crested earthern weir designed to pass 100 year storm.
Using broad crested weir equation H = (Q/Cw x L)213
where: Q = Q100 61.00 cfs
Cw = 3.0
Lengtheet
H = 0.77 feet
10. FOREBAY SIZING
Compute Actual Pond Volumes (using average end method)
Avg
Incr.
Incr. Cum.
Main BayVolume olume
v t'
Area (SF)
Area (SF)Depth
(FT)
Vol (CF l Vol (CF)
Pond Bottom
42 00
7,003
Bottom Veg Shelf
46 33
5T.8,830
4.33
38,234 38,234
Normal Pond
4800
15,856!
13,257
1.67
22,138 60,372
Main Bay Volume =
Forebay Volume
Pond Bottom
Normal Pond
Forebay Volume =
Total Pond Volume =
Forebay Volume equates to
Temp Storage Volume
Normal Pond
Temp. Pond Level
Temp. Pool Volume =
10 Yr Storage Volume
Temp Pond Level
Temp. Pond Level
60,372
Elevation Area (SF l Area (SF) Depth (FT) Vol CF Vol C
.............................
43.00
48.00 4,166. 3,028 5.00 15,140 15,140
15,140 CF
75,512 CF
20.0 % of Total Volume
Elevation Area (SF) Area (SF 1 Depth FT Vol (CF VolC
48.00 20,024
21,817 1.88 41,016 41,016
41,016 CF
Elevation Area (SF l Area (SF l Depth FT Vol CF Vol C
49.88 23,610
25,185 1.57 39,541 39,541

Temp. Pool Volume =
39,541 CF
10 torage Volume Elevation Area ($F) Area Depth T 6.87 Vol (CF1
Temp Pond Level 49.88 23,610
........................................................................
..................................................................
Temp. Pond Level 51 64 27,149 25,380 1.76 44,634 44,634
Temp. Pool Volume = 44,634 CF
11. SUMMARY
Pond Elevations:
Top Berm (minimum)
H= 0.77
100-Yr. Flood
H 100 = 1.76
10-Yr. Flood
H10 = 1.57
1-inch Storage
storage depth = 1.88
Permanent Pool
pond depth = 6
Pond Bottom
12. WET DETENTION BASIN SUPPLEMENT
Basin Bottom Elevation
42.00
Perm. Pool Elevation
48.00
Temp. Pool Elevation
49.88
Perm Pool Surface Area
20,024 SF
Drainage Area
12.66 AC
Impervious Area
7.74 AC
Perm. Pool Volume
75,512 CF
Temp Pool Volume
41,016 CF
Forebay Volume
15,140 CF
SAIDA
3.4554
Diameter of Orifice
2.00
Design Rainfall
1"
Design TSS Removal
90%
Relative
Actual
10.41
52.41
9.64
51.64 (emerg. weir elev)
9.45
51.45
7.88
49.88 (primary weir elev)
6.00
48.00 (invert out elev)

Stormwater Treatment &
Erosion Control Narrative
Shopping & Office Park — Holly Ridge
Dr. William Morgan, Sr. proposes to construct a five (5) building business park on a 16.78 acre tract located
on U.S. Highway 17 approximately 1 mile north from its intersection with N.C. 50 in Holly Ridge, Onslow
County. The proposed development includes an office building, strip mall, restaurant, motel & grocery store.
The site is currently undeveloped.
C.
The project site drains to an unnamed tributary of King Creek (SA;Sw,HQW) in the Cape Fear River Basin.
The proposed development activities are high density (percent impervious > 30 %), therefore, stormwater
treatment facilities are required. The attached Stormwater Plan includes a wet detention basin. This 20,024 sf
pond is situated on the southwest corner of the tract.
The stormwater pond is sized to accommodate 337,097 square feet of impervious area, allocated as follows:
Buildings
Streets
Parking
Sidewalks
Other
Reserve for Future
Total
Site
Offsite
Total
100,283 sf
-0-
100,283 sf
-0-
-0-
-0-
206,367 sf
-0-
206.367 sf
20,641 sf
-0-
20,641 sf
1,590 sf
-0-
1,590 sf
8,216 sf
-0-
8.216 sf
337,097 sf -0-
337,097 sf
The proposed pond is sized for 90% TSS removal. The pond does not incorporate pretreatment, other than
the forebay. The pond does not include a vegetated filter at the outlet.
All stormwater emanating from impervious surfaces that is generated on -site shall be collected and directed to
the stormwater pond by a system of sheet drainage, grassed swales and storm drainage pipes. The proposed
pond will discharge through a level spreader to a jurisdictional stream located at the southwestern boundary of
the tract. Wetlands delineation/evaluation (by others) has determined that there are no other wetlands within
the site.
The treatment system will require periodic maintenance. Maintenance frequency shall be dictated by pond
depths. Pond depths shall be checked by the owner on a quarterly basis. When measured depths in the are
less than 4.5' in the main pond, or less than 3.75' in the forebay, the pond shall be manually dewatered (pump)
and accumulated sediment removed and properly disposed of.
Site topography is gently to moderately sloping (0 — 8%), with the western portion of the tract sloping generally
toward the south and the eastern portion towards the southeast. Soils are loamy sand/sandy loam.
The entire area (15.5 acres) designated within "Clearing Limits" will be disturbed during initial construction.
The developer intends to construct buildings upon conclusion of infrastructure (parking, drainage, water &
sewer).

I