SW8060553_HISTORICAL FILE_20061219

STORMWATER DIVISION CODING SHEET
POST -CONSTRUCTION PERMITS
PERMIT NO.
SW8p�0553
DOC TYPE
❑ CURRENT PERMIT
❑ APPROVED PLANS
HISTORICAL FILE
❑ COMPLIANCE EVALUATION INSPECTION
DOC DATE
206Lo \2\c-1
YYYYMMDD

`;ti aF W ATF9
C Y
December 19, 2006
Mr. Byron Stratus, President
Stratus Management Company, Manager
Porter's Pointe, LLC
2609 Mimosa Place
Wilmington, NC 28403
Subject: Stormwater Permit No. SW8 060553
Porter's Pointe Subdivision
High Density Subdivision Project
New Hanover County
Dear Mr. Stratus:
Michael F Easley, Governor
William Ross Jr., Secretary
North Carolina Department of Environment and Natural Resources
Alan W Klimek, P.E. Director
Division of Water Quality
The Wilmington Regional Office received a complete modified Stormwater Management
Permit Application for Porters Pointe Subdivision on September 29, 2006. 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 060553, dated December 19, 2006, for the construction of the subject project.
This permit shall be effective from the date of issuance until December 19, 2016, 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 thirty (30) days
following receipt of this permit. This request must be in the form of a written petition,
conforming to Chapter 150B 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 Linda Lewis, or me at [phone].
Sincerely,
Edward Beck
Regional Supervisor
Surface Water Protection Section
ENB/arl: S:\WQS\STORMWATER\PERMIT\060553mod.dec06
cc: Steven Thomas, PE, Stewart Engineering
Tony Roberts, New Hanover County. Inspections
Beth E. Wetherill, New Hanover County Engineering
Linda Lewis
Wilmington Regional Office N8` Carolina
Central Files �vatura//y
North Carolina Division of Water Quality 127 Cardinal Drive Extension Wilmington, NC 28405 Phone [phone] Customer Service
Wilmington Regional Office Internet www.newateraualnv or Fax [phone]
An Equal OppodunitylAffrmative Action Employer— 50%Recycledl10% Post Consumer Paper

State Stormwater Management Systems
Permit No. SW8 060553
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
Byron Stratus, Stratus Management Co. & Porter's Pointe, LLC
Porter's Pointe Subdivision
Porters Neck Road, Wilmington, New Hanover County
FOR THE
construction, operation and maintenance of 2 infiltration basins 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 December 19, 2016, and
shall be subject to the following specified conditions and limitations:
1. DESIGN STANDARDS
1. 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 subdivision is
permitted for 61 lots, each allowed 4,015 square feet of built -upon area.
3. Approved plans and specifications for this project are incorporated by reference
and are enforceable parts of the permit.
4. Each basin must be operated with a 40-50' level spreader prior to discharge into
the wetlands.
5. 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.
Page 2 of 8

State Stormwater Management Systems
Permit No. SW8 060553
6. The following design elements have been permitted for the infiltration basins, and
must be provided in the system at all times.
� �-
M
Units,
'Infiltration. Basin,
L;
'In iltration-1Basm=`
-
-
Ain DA=-1r'
tB'in D'A-2`
Drainage Area
12.56
8.83
Onsite
Acres
12.56
8.83.
Offsite
0
0
Total Impervious Surfaces
223,596
183,759
Lot BUA at 4,015 ft2/lot
128,700
89,375
Roads/Parking
ft2
76,172
83,702
Sidewalks
10,994
10,682
Other
22,730
0
Offsite
0
0
Basin Depth
feet
6.0
6.0
Design Storm
inches
1.5
1.5
Bottom Elevation
FMSL
18.0
18.0
Permitted Surface Area Bottom
ft
7,454
7,389
Permitted Storage Volume
ft
60,298
65,046
Storage/Bypass Elevation
FMSL
24.0
24.0
Expected Infiltration Rate
in/hr
9.0
8.8
Time to Draw Down
hours
8.0
8.18
Type of Soil
Kenansville
Receiving Stream
Pages Creek
River Basin
Cape Fear
Stream Index Number
_
-
18 87-22
Classification of Water Body
SA;HQW
It. SCHEDULE OF COMPLIANCE
1. No homeowner/lot owner/developer shall fill in, alter, or pipe any drainage feature
(such as swales) shown on the approved plans as part of the stormwater
management system without submitting a revision to the permit and receiving
approval from the Division.
2. The permittee is responsible for verifying that the proposed built -upon area for
the entire lot, including driveways and sidewalks, does not exceed the allowable
built -upon area. Once the lot transfer is complete, the built -upon area may not be
revised without approval from the Division of Water Quality, and responsibility for
meeting the built -upon area limit is transferred to the individual property owner.
3. 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.
4. During construction, erosion shall be kept to a minimum and any eroded areas of
the system will be repaired immediately. Infiltration systems should not be used
as erosion control devices, due to the potential clogging. 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.
Page 3 of 8

State Stormwater Management Systems
Permit No. SW8 060553
5. 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.
6. 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 the approved plans, regardless of size.
b. Project name change.
C. Transfer of ownership.
d. Redesign or addition to the approved amount of built -upon area.
e. Further subdivision, acquisition, 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.
7. The Director may determine that other revisions to the project should require a
modification to the permit.
8. 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.
9. The permittee shall at all times provide the operation and maintenance
necessary to assure that all components of the permitted stormwater system
function 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. Mowing and revegetation of side slopes.
d. Immediate repair of eroded areas.
e. Maintenance of side slopes in accordance with approved plans and
specifications.
f. Debris removal and unclogging of structures, orifice, catch basins and
piping.
g. Access to all components of the system must be available at all times.
10. 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.
11. Permanent seeding requirements for the stormwater control must follow the
guidelines established in the North Carolina Erosion and Sediment Control
Planning and Design Manual.
12. Prior transfer of the permit, the stormwater facilities will be inspected by DWQ
personnel. The facility must be in compliance with all permit conditions. Any
items not in compliance must be repaired or replaced to design condition prior to
the transfer. Records of maintenance activities performed to date will be
required.
Page 4 of 8

State Stormwater Management Systems
Permit No. SW8 060553
13. Prior to the sale of any lot, the following deed restrictions must be recorded:
a. The following covenants are intended to ensure ongoing compliance with
State Stormwater Management Permit Number SW8 060553, as issued
by the Division of Water Quality under NCAC 2H.1000.
b. The State of North Carolina is made a beneficiary of these covenants to
the extent necessary to maintain compliance with the Stormwater
Management Permit.
C. These covenants are to run with the land and be binding on all persons
and parties claiming under them.
d. The covenants pertaining to stormwater may not be altered or rescinded
without the express written consent of the State of North Carolina, Division
of Water Quality.
e. Alteration of the drainage as shown on the approved plans may not take
place without the concurrence of the Division of Water Quality.
f. The maximum built -upon area per lot is 4,015 square feet. This allotted
amount includes any built -upon area constructed within the lot property
boundaries, and that portion of the right-of-way between the front lot line
and the edge of the pavement. Built upon area includes, but is not limited
to, structures, asphalt, concrete, gravel, brick, stone, slate, coquina and
parking areas, but does not include raised, open wood decking, or the
water surface of swimming pools.
g. All runoff on the lot must drain into the permitted system. This may be
accomplished through providing roof drain gutters which drain to the
street, grading the lot to drain toward the street, or grading perimeter
swales and directing them into the pond or street. Lots that will naturally
drain into the system are not required to provide these measures.
h. Built -upon area in excess of the permitted amount will require a permit
modification.
14. A copy of the recorded deed restrictions must be submitted to the Division within
30 days of the date of recording the plat, and prior to selling lots. The recorded
copy must contain all of the statements above, the signature of the Permittee, the
deed book number and page, and the stamp/signature of the Register of Deeds.
15. This permit shall become voidable unless the facilities are constructed in
accordance with the conditions of this permit, the approved plans and
specifications, and other supporting data.Built upon area includes, but is not
limited to, structures, asphalt, concrete, gravel, brick, stone, slate, coquina and
parking areas, but does not include raised, open wood decking, or the water
surface of swimming pools.
III. GENERAL CONDITIONS
This permit is not transferable to any person or entity except after notice to and
approval by the Director. In the event there is either a desire for the facilities to
change ownership, or there is a name change of the Permittee, a
"Name/Ownership Change Form" must be submitted to the Division of Water
Quality accompanied by appropriate documentation from the parties involved.
This may include, but is not limited to, a deed of trust, recorded deed restrictions,
Designer's Certification and a signed Operation and Maintenance plan. The
project must be in good standing with DWQ. The approval of this request will be
considered on its merits and may or may not be approved.
2. The permittee is responsible for compliance with all of the terms and conditions
of this permit until such time as the Director approves the transfer request.
3. 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.
Page 5 of 8

State Stormwater Management Systems
Permit No. SW8 060553
4. 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) that have jurisdiction.
5. 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.
6. The permit may be modified, revoked and reissued or terminated for cause. The
filing of a request for a permit modification, revocation and reissuance or
termination does not stay any permit condition.
7. Permittee grants permission to staff of the DWQ to access the property for the
purposes of inspecting the stormwater facilities during normal business hours.
8. The permittee shall notify the Division of any name, ownership or mailing address
changes within 30 days.
9. 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.
Permit issued this th 19`h day of December 2006
NORTH ROLINA�RONMENTAL MANAGEMENT COMMISSION
for Alan W. Klimek, P.E., Director
Division of Water Quality
By Authority of the Environmental Management Commission
Page 6 of 8

- 'OFFICE USE ONLY -
Date Received
Fee Paid;
Permit Number
State of North Carolina
Department of Environment and Natural Resources
Division of Water Quality
STORMWATER MANAGEMENT PERMIT APPLICATION FORM
This form may be photocopied for use as an original
I. GENERAL INFORMATION
1. Applicants name (specify the name of the corporation, individual, etc. who owns the project):
Porter's Pointe. LLC
2. Print Owner/Signing Official's name and title (person legally responsible for facility and compliance):
Byron StratasMer berMarteder Pr-eSt4entl ,erJir2[US �Zt12G2ih2Al COM-al tr-
3. Mailing Address for person listed in item 2 above:
2609 Mimosa Place
City: Wimlington State: NC Zip. 28403
Telephone Number ( ) [phone]
4. Project Name (subdivision, facility, or establishment name - should be consistent with project name on plans,
specifications, letters, operation and maintenance agreements, etc.):
Porter's Pointe Subdivision
5. Location of Project (street address):
Porter's Neck Road between US 17 and Lantana Lane
City: Harnett
New Hanover
6. Directions to project (from nearest major intersection):
Traveling north on US 17, take a right on Porter's Neck Road. The project site is approximately 0.25 miles down
Porter's Neck Road on the right.
7. Latitude: 34d 17.56'
Longitude: 77d 47.02' of project
8. Contact person who can answer questions about the project:
Name: David Boyette, Stewart Engineering Inc. Telephone Number: ( ) [phone]
II. PERMIT INFORMATION:
1. Specify whether project is (check one): New Renewal Modification
Form SWU-101 Version 3.99 Page I of

2. If this application is being suht„itted as the r —dt of a renewal or modification to an existing p -_mir, list the
existing permit number_ SW8 060553 and its issue date (if known)_ July 17 2006
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 X 404/401 Permit NPDES Stormwater
Information on required state permits can be obtained by contacting the Customer Service Center at
1-877-623-6748.
III. 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 from the proposed project will be collected in a piped drainage system and carried to one of two infiltration basins
2. Stormwater runoff from this project drains to the Cape Fear River basin.
3. Total Project Area: 24.29 acres
5. How many drainage areas does the project have? 2
4. Project Built Upon Area: 39.89
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 information for each area provided in the same format as below.
(r'sl' A) (/303/�7 5 )
Basin Information `-_ _
�. Drainage Areal -
`Drainage Area:2` - -
Receiving Stream Name
Pages Creek
Pages Creek
Receiving Stream Class
SA-H W
SA-HQW
Drainage Area
12.56 ac
8.38 ac
Existing Impervious* Area
0 ac
0 ac
Proposed Impervious*Area
5.48 ac
4.22
% Impervious* Area (total)
43 63%
50 36%
In per5iou's Surface Area- .
�. _ Drainage Areal `_.:
Drainage Area'2
On -site Buildings
128,700 sf
89,375 sf
On -site Streets
60,332 sf
72,702 sf
On -site Parking
15.840 sf
11,000 sf
On -site Sidewalks
10,994 sf
10682 sf
Other on -site
22 730 sf
----------
Off-site
---- --------
-----------
Total: 238,596 sf
Total: 183,759 sf
Impervious area is dented 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

7. How was the off -site impervious area listed above derived? Calculated based upon building footprint and lot layout
for each lot as shown on plans
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
1. The following covenants are intended to ensure ongoing compliance with state stormwater management permit number
as issued by the Division of Water Quality. These covenants may not be
changed or deleted without the consent of the State.
Z. No more than 4015 sf square feet of any lot shall be covered by structures or impervious materials.
Impervious rnateriais inciode asphalt, gravel, concrete, brick, stone, slate or similar material but do not include wood
decking or the water surface of swimming pools.
3. Swales shall not be filled in, piped, or altered except as necessary to provide driveway crossings.
4. Built -upon area in excess of the permitted amount requires a state stormwater management permit modification prior to
construction.
5. All permitted runoff from outparcels or future development shall be directed into the permitted stormwater 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 Stormwater and General Permits Unit at [phone] for the status
and availability of these forms.
Form SWU-102
Wet Detention Basin Supplement
Form SWU-I03
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-I07
Underground Infiltration Trench Supplement
Form SWU-I08
Neuse River Basin Supplement
Form SWU-109
Innovative Best Management Practice Supplement
Form SWU-101 Version 3.99 Page 3 of 4

VI. 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.
Please indicate that you have provided the following required information by initialing in the space provided
next to each item.
Ini ials
• Original and one copy of the Stormwater Management Permit Application Form
• One copy of the applicable Supplement Form(s) for each BMP
• Permit application processing fee of $420 (payable to NCDENR)
• Detailed narrative description of stormwater treatment/management �)
• Two copies of plans and specifications, including
- 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)
VII. 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 Boyette Stewart Engineering Inc _
Mailing Address: 128 E Hargett Street Suite 300
City: Raleigh State: NC Zip: 27601
Phone: ( ) [phone] Fax: ( ) [phone]
VIll. APPLICANT'S CERTIFICATION
I, (print or type name of person listed in General Information, item 2) Byron Stratas
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 recorde nd th p ed project complies with the requirements of 15A
NCAC 2H .1000.
Signature: i Date:
2Z
Form SWU-101 Version 3.99 Page 4 of 4

CCS
,
STEWART
LETTER OF TRANSMITTAL
TO
FROM
553 KOO
Linda Lewis
Steve Thomas
NCDENR, DWQ
Civil Department Manager
127 Cardinal Drive Extension
910.796.0145 x 403
Wilmington, NC 28405
DATE SENT VIA
September 29, 2006 Hand Delivery
PROJECT NUMBER PROJECT NAME
C6005 Porter's Pointe Subdivision - Permit Revision
COPIES DATE DESCRIPTION
1
9 8 06
Revised Plan Sheets (in addition to the 1 set previously
delivered
1
9/11/06
Revised SIA & Storm Drainage & Erosion Control
Calculations in addition to the 1 set previously delivered
1
9 29 06
Completed Application and Supplements
1
9 21 06
Check in the amount of $420.00 for review fee
®
For approval
❑
i For review & comment
❑
Returned for corrections
®
For your use
❑
Approved as submitted
❑
Returned after review
®
As requested
❑
Approved as noted
Resubmit copies for approval
COMMENTS
Linda,
Please find the enclosed information in addition to our last submittal of 1 plan set
and 1 SIA. Please let me know if you have any questions or need anything further.
Thank you,
SIGNE
2�
Steve Thomas, PE - Civil Dept. Manager
COPIED TO
Brian Eckel - Cape Fear Commercial
Chris Reid - Thomas Construction
ENGINEERING. INNOVATION. SOLUTIONS.^ 201 N. FRONT ST. WILMINGTON, NC T 910.796 0145
SUITE 103 2S401 F 910.796.0146

Stormwater Impact Analysis
For the proposed
Porter's Pointe Subdivision
Harnett Township, North Carolina
Prepared for
Cape Fear Commercial
Prepared By
Stewart Engineering, Inc.
O "
STEWART
May 17, 2006
Revised June 30, 2006
Revised September 8, 2006
RECEIVED
SEP 2 9 2006
DW
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Storm Impact Analysis
For
Porter's Pointe Subdivision
Harnett Township, North Carolina
Prepared for:
Cape Fear Commercial
Prepared by:
Stewart Engineering, Inc.
128 E. Hargett Street, Suite 300
Raleigh, NC 27601
919.719.1045
Stewart Project No. C6005
September 8, 2006

STORMWATER IMPACT ANALYSIS
PORTER'S POINTE SUBDIVISION
HARNETT TOWNSHIP, NORTH CAROLINA
EXECUTIVE SUMMARY
This Stormwater Impact Analysis has been prepared specifically to address
the requirements of Section 15A NCAC 02H .1005 of the North Carolina
Administrative Code as it pertains to the stormwater requirements for coastal
counties and the stormwater requirements of New Hanover County. The project
site does not drain to Outstanding Resource Waters, however it is within one-half
mile of a body of water classified as SA water. Three infiltration basins will be
utilized to capture and infiltrate the runoff from the first one and one-half inches of
rainfall in order to satisfy Section 15A NCAC 02H.1005 of the North Carolina
Administrative Code. The basins have also been sized to retain sufficient runoff to
hold the post -development peak flow for the 2-, 10-, and 25-year storms to pre -
development levels.
Site Information
Porter's Pointe Subdivision is located off of Porter's Neck Road in Harnett
Township in New Hanover County. The site is within the Cape Fear River Basin and
drains to an unnamed tributary of Pages Creek which is classified as SA waters.
Jurisdictional wetlands are present on site, along with several pockets of isolated
wetlands. The site drains to the southeast with slopes ranging from 1%-3%. The
site receives a small amount of offsite drainage from the northwest that sheet flows
onto the site.
Proposed Improvements
The project proposes to subdivide the property into 61 lots ranging in size
from 0.15ac to 0.37ac with an average size of 0.19 ac. A building and driveway
footprint have been shown for each lot which has been used to determine the
proposed impervious area. The development will consist of primary roadways
which will be asphalt paving with curb and gutter and sidewalk and alleys from
which the lots will be accessed. The alleys will consist of two 3' wide concrete strips
with 2' of gravel in between and 1' on either side for a total width of 10'. For
purposes of this report, the entire 10' section of the alley is considered impervious
area.
Two infiltration basins will be constructed on -site to provide water quality
treatment to meet the State regulations and peak flow reduction mandated by New
Hanover County. Both infiltration basins will be above -grade basins which will be
located in the southeastern and southwestern corners of the site. Each basin is
equipped with a bypass for larger storms. These bypass pipes discharge to a
vegetated swale.

Design Requirements
Per Section 15A NCAC 02H .1005 (2) of the North Carolina Administrative
Code for sites that are within 0.5 mile of SA waters the State Stormwater
Regulations mandate that the runoff from the first one and one-half inches of
rainfall be captured and infiltrated. The infiltration devises are designed in
accordance with Rule .1008 of Section 15A NCAC 02H and have a bypass and a
vegetated filter to treat runoff from rainfall events greater than one and one-half
inches.
Pursuant to the New Hanover County Stormwater Design Manual the post -
development peak flow for the 2-, 10-, and 25-yr storms must be controlled to pre -
development levels.
Design Procedure
Exhibit maps EX-1 and EX-2 which are included in this report show the
existing and proposed drainage areas, respectively. The existing and proposed
drainage areas were determined using field surveyed topographic information.
Only one drainage area is utilized for the existing condition as the site generally
flows to the southeastern property boundary. In the proposed condition, the site is
divided into two drainage areas with one draining to each infiltration basin.
Infiltration rates were determined by S&ME, INC using a double -ring infiltrometer
test. The seasonal high groundwater level was determined by Vince Lewis of
NCDENR-DWQ.
In order to meet the State stormwater regulations, each basin has been sized
to capture and infiltrate the runoff from the first one and one-half inches of rainfall.
This volume of runoff is calculated using the Simple Method as outlined in the State
BMP manual.
The New Hanover County Stormwater Design Manual stipulates that the
post -development peak flow for the 2-, 10-, and 25-year storms must be held to
pre -development levels. The Soil Conservation Service (SCS) Hydrograph
Formulation Method was used to compute peak flow for both the existing and
proposed drainage areas. A Curve number (CN) of 60 was used for the existing
condition where as 98 and 69 were used in the proposed condition for impervious
and open space respectively. The time of concentration in the pre -development
condition was calculated using the TR-55 method. In the post -development
condition, a conservative time of concentration of 5 minutes was used. The
software program entitled Hydroflow Hydrographs by Intelisolve was used to
perform the calculations for pre- and post -development peak flow.
Overall Results / Summary
Table 1 below shows the statistics for each infiltration basin.
Top
Bottom
Groundwater
Storage
Total
Infiltration
Basin
Elevation
Elevation
Elevation
Elevation
Storage
Rate
ft
ft
ft
ft
cf
in/hr
A
25.0
18
16
24.0
60 298
9.0
B
25.0
18
16
24.0
65,046
8.8
Table 1 - Infiltration Basin Statistics

Table 2 shows the data pertaining to the State stormwater regulations. Each basin
has more than enough storage volume to capture the runoff from the first one and
one-half inches of rainfall. The drawdown time for each basin is also well below the
maximum of five days.
Required
Providedl
Infiltration
Infiltration
Drawdown
Bypass
Basin
Storage
Storage
Rate
Rate
Time
Provided
cf
cf
in/hr
cfs
hr
Yes/No
A
30 274
60 298
9.0
2.64
8.00
Yes
B
1 22,962
1 65,046
8.8
3.06
8.18
Yes
Table 2 - State Stormwater Table
Table 3 shows the pre- and post -development peak Flow rates for the 2-, 10-, and
25-year storms. As is required by New Hanover County, the post -development
peak flow rate is less than the post -development peak flow rate for the site. Please
note that the infiltration rate for each basin has not been included in the peak flow
rate because this water is not discharged from the site.
2-year
cfs
10 year
cfs
25 year
cfs
Pre -development Peak Flow
DA-A
2.51
9.35
14.35
DA-B
1.96
7.56
11.78
Post -development Peak Flow
DA-A
0.00
3.88
13.03
DA-B
0.00
0.00
0.00
Table 3 - Peak Flow Rates
Conclusions
Based on the results of this Stormwater Impact Analysis, the requirements of
Section 15A NCAC 02H .1003 of the North Carolina Administrative Code as it
pertains to the stormwater requirements for coastal counties have been met for the
proposed project. Runoff from all new impervious area has been captured and
treated in one of two proposed infiltration beds.
The requirements of the New Hanover County Stormwater Design Manual
have also been met in that the post -development peak flow rates for the 2-, 10-,
and 25-years storms have been held below pre -development levels. Also, the 100-
yr water surface elevation in both infiltration basins is 0.5' below the top of dam
which will ensure that no downstream structures are inundated in the 100-yr storm.

i'
�,a. fir„ , :..''•��,.., ` i.; A ,. � �:t..d � _
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t
0 0.3 0.6 0.9 1.2 1.5 km
0 0.2 0.4 0.6 0.8 1 mi
Map center is UTM 18 243924E 3797542N (WGS84/NAD83)
Scotts Hill quadrangle
Projection is UTM Zone 18 NAD83 Datum G=-1.568

\ EXISTING DRAINAGE AREAS o
\ \ m X
r ,\ DA-A
LU
`�`I
N \I \♦ i / / ' \� `1 `\ CN =TOT60AREA = 11.27AC c
1 1
I Jill TIC =15MIN
� o s
Q2=2.51 CFS
Q10 = 9.35 CFS
z m
Q25 = 14.35 CFS T
DA-B (L w 8
TOTAL AREA = 9.96 AC
TIC = 21 MIN W a
�. I;Q
`U)
Y: i \\ \`-- I II Q2 = 1.96 CFS O O Z o
--►----- - - \ �� ,r_, ; ' `♦, '". / 1' 1 Q10 = 7.56 CFS (_ U) o w
Q25 = 11.78 CFS I- >
W
___ _ __ U7 of------�♦\ d = W
\1\ � � �//� ._ � �, � ___„+_ , i r' ' I I •�� �ss'� �� �-.,���.\\` i III I W
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i
i
/
- - -
----
/
/
0
PUBLIC
01
J
. i.
P
It
�\ 1 PROPOSED DRAINAGE AREAS 9 N
x
\ ` ` DA-A W
TOTAL AREA = 12.56 AC -
all �` �` TIC = 5 MIN o 0
\\ CD N m
I 1 ' Q2 = 0.00 CFS "'
1
Q10 = 3.88 CFS
Q25 = 13.03 CFS z m
U C Y
1 I j DA-B a o
_ TOTAL AREA = 8.38 AC to
1 CN=82
1 TIC = 5 MIN W
tl j1 a
~ Z
i 1 i i Q2 = 0.00 CFS p Z o
Q10 = 0.00 CFS a �:
i i 1 Q25 = 0.00 CFS U) > W
1 i lu` w o
Z
cf
d O� =w
j 11 1, W
Ilp �
Q
1 Z
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'woe o3
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ee=o==E3
1
1 inch --

C(V
.
STEWART
Infiltration Basin Sizing
Basin A
Project Porter's Pointe
Project No. C6005
Date 8-Sep-06
Storage Required for first one and one-half inches over entire drainage area
Drainage Area
Required Storage for I st 1.5-inch of runoff
Total Drainage Area = 12.56 ac
Simple Method
Total Impervious Area = 5.48 ac
Percent Impervious = 44%
Rv = 0.05 + 0.009(1)
1 = % impervious = 44%
Rv = 0.66 in
Volume= 30274 cf
Calculation Methods are taken from DE14NR Stormwater Best Management Practices Manual, November 1995
Storage Volume Required = 30274 cu ft
Contour
(ft)
Area
(ft2)
Incr
Vol
(113)
Accum
Vol
(ft3)
Stage
Z
(ft)
In S
In Z
Zest
18
7454
0
0
0
19
8254
7854
7854
1
8.9687782
0
1.082113929
20
9082
8668
16522
2
9.7124481
0.6931472
2.021518848
21
9938
9510
26032
3
10.167082
1.0986123
2.962087572
22
10821
10380
36412
4
]0.50264
1 1.3862944
13.927000426
23
11729
11275
47687
5
10.772404
1.6094379
4.926200752
24
12663
12196
59883
6
11.00014
1 1.7917595
1 5.96520139
25
13622
13143
73025
7
11.198557
1 1.9459101
7.047551454
Ks = 7150 b = 1.19
Storage Volume Provided @ Elev. 24.00 = 60298 cu ft
Drawdown Time
Infiltration Rate = 9 in/hr
Depth of Storage = 72 in
Drawdown Time = 8.00 hr

COS
STEWART
Infiltration Basin Sizing
Basin B
Project Porter's Pointe
Project No. C6005
Date 8-Sep-06
Storage Required for first one and one-half inches over entire drainage area
Drainage Area
Required Storage
for 1 st 1.5-inch of runoff
Total Drainage Area = 8.38 ac
Simple Method
Total Impervious Area = 4.22 ac
Percent Impervious = 50%
Rv = 0.05 + 0.009(I)
I = % impervious =
50%
Rv =
0.75 in
Volume=
22962 cf
Calculation Methods are taken from DEHNR Stormwater Best Management Practices Manual, November 1995
Storage Volume Required = 22962 cu ft
Contour
(ft)
Area
(ft2)
Incr
Vol
(0)
Accum
Vol
(1`13)
Stage
Z
(ft)
In S
In Z
Zest
18
7389
0
0
0
19
8383
7886
7886
1
8.9728
0.0000
1.0943
20
9497
8940
16826
2
9.7307
0.6931
2.0164
21
10777
10137
26963
3
10.2022
1.0986
2.9493
22
1 11452
1 11115
1 38078
4
1 10.5474
1.3863
1 3.8959
23
1 12835
12144
1 50221
1 5
10.8242
1.6094
4.8703
24
14288
13562
63783
6
11.0632
1.7918
5.9058
25
1 15801
15045 1
78827
1 7
11.2750
1 1.9459
7.0057
Ks = 7052 b = 1.24
Storage Volume Provided @ Elev. 24.00 = 65046 cu ft
Drawdown Time
Infiltration Rate = 8.8 in/hr
Depth of Storage = 72 in
-Drawdown Time = 8.18 hr I

lydrograph Return Period Recap
Hyd.
Hydrograph
Inflow
Peak Outflow (cfs)
Hydrograph
No.
type
Hyd(s)
description
(origin)
1-Yr
2-Yr
3-Yr
5-Yr
10-Yr
25-Yr
50-Yr
100-Yr
1
SCS Runoff
--
2.51
--
--
9.35
14.35
18.79
23.51
Ex. area to Prop Basin A
2
SCS Runoff
--
--
1.96
---
--
7.56
11.78
15.51
19.48
Ex. area to Prop Basin B
3
SCS Runoff
--
16.80
30.45
38.59
45.10
51.63
Drainage Area A
4
SCS Runoff
----
---
12.29
---
---
21.56
27.02
31.38
35.74
Drainage Area B
5
Reservoir
3
2.25
657
15.57
3266
43.54
Basin A Routing
6
Reservoir
4
2.08
--
2.69
3.04
6.17
9.88
Basin B Routing
Proj. file: C6005-NCDOT.gpw
Monday, Sep 11 2006, 7:07 AM

iydrograph Summary Report
Hyd.
No.
Hydrograph
type
(origin)
Peak
flow
(cfs)
Time
interval
(min)
Time to
peak
(min)
Volume
(cult)
Inflow
hyd(s)
Maximum
elevation
(ft)
Maximum
storage
(cuft)
Hydrograph
description
1
SCS Runoff
2.51
2
158
17,869
—
--
--
Ex. area to Prop Basin A
2
SCS Runoff
1.96
2
164
16,486
—
Ex. area to Prop Basin B
3
SCS Runoff
16.80
2
144
66,336
—
Drainage Area A
4
SCS Runoff
12.29
2
144
48,293
—
--
--
Drainage Area B
5
Reservoir
2.25
2
326
66,332
3
21.95
35,943
Basin A Routing
6
Reservoir
2.08
2
248
48,288
4
20.54
22,330
Basin B Routing
C6005-NCDOT.gpw
Return Period: 2 Year
Monday, Sep 11 2006, 7:07 AM

iydrograph Summary Report
Hyd.
No.
Hydrograph
type
(origin)
Peak
flow
(cfs)
Time
interval
(min)
Time to
peak
(min)
Volume
(cult)
Inflow
hyd(s)
Maximum
elevation
(ft)
Maximum
storage
(cuft)
Hydrograph
description
1
SCS Runoff
9.35
2
154
47,758
—
--
Ex. area to Prop Basin A
2
SCS Runoff
7.56
2
160
44,062
—
--
Ex. area to Prop Basin B
3
SCS Runoff
30.45
2
144
119,595
--
--
Drainage Area A
4
SCS Runoff
21.56
2
144
84,923
—
--
Drainage Area B
5
Reservoir
6.57
2
198
119,590
3
24.13
61,597
Basin A Routing
6
Reservoir
2.69
2
292
84,918
4
22.76
48,215
Basin B Routing
C6005-NCDOT.gpw
Return Period: 10 Year
Monday, Sep 11 2006, 7:07 AM

iydrograph Summary Report
Hyd.
No.
Hydrograph
type
(origin)
Peak
flow
(cfs)
Time
interval
(min)
Time to
peak
(min)
Volume
(cult)
Inflow
hyd(s)
Maximum
elevation
(ft)
Maximum
storage
(cuft)
Hydrograph
description
1
SCS Runoff
14.35
2
154
68,929
--
----
----
Ex. area to Prop Basin A
2
SCS Runoff
11.78
2
158
63,595
—
--
Ex. area to Prop Basin B
3
SCS Runoff
38.59
2
144
152,110
—
Drainage Area A
4
SCS Runoff
27.02
2
144
107,076
—
Drainage Area B
5
Reservoir
15.57
2
156
152,106
3
24.30
63,790
Basin A Routing
6
Reservoir
3.04
2
320
107,072
4
23.94
64,682
Basin B Routing
C6005-NCDOT.gpw
Return Period: 25 Year
Monday, Sep 11 2006, 7:07 AM

iydrograph Summary Report
Nyd.
No.
Hydrograph
type
(origin)
Peak
flow
(cfs)
Time
Interval
(min)
Time to
peak
(min)
Volume
(cult)
Inflow
hyd(s)
Maximum
elevation
(ft)
Maximum
storage
(cuft)
Hydrograph
description
1
SCS Runoff
18.79
2
152
87,267
—
Ex. area to Prop Basin A
2
SCS Runoff
15.51
2
158
80,514
—
--
Ex. area to Prop Basin B
3
SCS Runoff
45.10
2
144
178,522
---
---
Drainage Area A
4
SCS Runoff
31.38
2
144
125,002
--
--
---
Drainage Area B
5
Reservoir
32.66
2
152
178,518
3
24.52
66,733
Basin A Routing
6
Reservoir
6.17
2
204
124,997
4
24.11
67,313
Basin B Routing
C6005-NCDOT.gpw
Return Period: 50 Year
Monday, Sep 11 2006, 7:07 AM

fydrograph Summary Report
Hyd.
No.
Hydrograph
type
(origin)
Peak
flow
(cfs)
Time
Interval
(min)
Time to
peak
(min)
Volume
(cult)
Inflow
hyd(s)
Maximum
elevation
(ft)
Maximum
storage
(cuft)
Hydrograph
description
1
SCS Runoff
23.51
2
152
106,683
—
--
Ex. area to Prop Basin A
2
SCS Runoff
19.48
2
156
98,427
—
Ex. area to Prop Basin B
3
SCS Runoff
51.63
2
144
205,292
—
--
---
Drainage Area A
4
SCS Runoff
35.74
2
144
143,124
—
--
Drainage Area B
5
Reservoir
43.54
2
148
205,288
3
24.64
68,305
Basin A Routing
6
Reservoir
9.88
2
172
143,119
4
24.19
68,581
Basin B Routing
C6005-NCDOT.gpw
Return Period: 100 Year
Monday, Sep 11 2006, 7:08 AM

STEWART
LETTER OF TRANSMITTAL
TO
FROM
Linda Lewis
Steve Thomas
NCDENR, DWQ
Civil Department Manager
127 Cardinal Drive Extension
910.796.0145 x 403
Wilmington, NC 28405
DATE SENT VIA
September 12, 2006 Hand Delivery
PROJECT NUMBER PROTECT NAME
C6005 Porter's Pointe Subdivision - Permit Revision
COPIES DATE DESCRIPTION
1
9/8/06
Revised Plan Sheets
1
9/11/06
Revised SIA & Storm Drainage & Erosion Control
Calculations
®
For approval
❑
For review & comment
❑
Returned for corrections
®
For your use
❑
Approved as submitted
❑
Returned after review
®
As requested
❑
Approved as noted
❑
Resubmit copies for approval
COMMENTS
Linda,
We were required to make the changes shown on the revised construction drawings
to meet the NCDOT requirements for acceptance. The changes are essentially very
minor, but did affect the stormwater calculations, as this resubmittal shows. Please
let me know if you have any questions or need anything further.
Thank you,
SIGNED COPIED TO
Brian Eckel - Cape Fear Commercial
Y
Steve Thomas, PE - Civil Dept. Manager
Chris Reid - Thomas Construction
ENGINEERING. INNOVATION. SOLUTIONS.^
201 N. FRONT ST. WILMINGTON, NC T 910.796.0145
SUITE 103 28401 F 910.796.0146

Out of Office AutoReoly: SV 060553 Porter's Pointe Subdivision
Subject: Out of Office AutoReply: SW8 060553 Porter's Pointe Subdivision
From: "Stephen Thomas" <[e-mail]>
Date: Mon; 18 Sep 2006 17:12:49 -0400
To: "Linda Lewis" <[e-mail]>
1 will be o6t of the office until Monday, September 25, 2006. if you need
immediate assistance, please contact either Andy Heath [e-mail] or
Dave Boyette at [e-mail]. Thank you.
I of] 9/18/2006 5:15 PM

S W8 060553 Porter's Pointe Subdivision
Subject: SW8 060553 Porter's Pointe Subdivision
From: Linda Lewis <[e-mail]>
Date: Mon, 18 Sep 2006 17:12:44 -0400
'ro: Stephen Thomas <[e-mail]>
Steve:
On September 12, 2006, the Division received a package that was labelled as a
"Permit Revision" to the subject project, however there was no application,
supplement or application fee provided.
Please tell me exactly what is being proposed, and exactly how the NCDOT changes
affected the project. If the changes have increased the proposed SUA or will cause
a modification to one of the permitted systems, then a full permit modification
with fee is required.
Linda
I of 1 9/18/2006 5:12 PM