HomeMy WebLinkAboutSW7070127_CURRENT PERMIT_20070209STORMWATER DIVISION CODING SHEET
POST -CONSTRUCTION PERMITS
PERMIT NO.
SW�C�� 7
DOC TYPE
VP CURRENT PERMIT .
❑ APPROVED PLANS
❑ HISTORICAL FILE
❑ COMPLIANCE EVALUATION INSPECTION
DOC DATE
YYYYMMDD
W ATFRO
Michael F. Easley, Governor
�OF
G
Secretary
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William G. Ross Jr.,
North Carolina Department of Environment and Natural Resources
O � Y
Alan W. Klimek, P.E. Director
Division of Water Quality
February 9, 2007
Mr. Donald Dove, Member Manager
1212 Butterworth Court
Stevensville, MD 21666
Subject: Permit No. SW7070127
The Village at Columbia
High Density Stormwater Project
Tyrrell County
Dear Mr. Dove:
The Washington Regional Office received a complete Stormwater Management Permit
Application for The Village at Columbia on February 2, 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. SW7070127 dated February 9, 2007, for the construction of the subject
project.
This permit shall be effective from the date of issuance until February 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 and In the
submitted application. 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 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 either Scott Vinson, or me at (252) 946-6481,
Since ely,
AL
I ge
Regional Supervisor
Surface Water Protection Section
AH/sav: C:\STORMWATER\PERMIT\SW7070127
cc: Todd Tripp, PE
Tyrrell County Building Inspections
Aashington Regional Office
Central Files
North Carolina Division of Water Quality Washington Regional Office Phone (252) 946-6481 FAX (252) 946-9215 Customer Service
Internet: www.ncwatercualirv.ora 943 Washington Square Mall, Washington, NC 27889 1-877-623-6748
An Equal OpportunitylARrmative Action Employer — 50% Recycl&10% Post Consumer Paper
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State Stormwater Management Systems
Permit No. SW7070127
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
The Village at Columbia, LLC
The Village at Columbia
Tyrrell County
FOR THE
construction, operation and maintenance of a wet detention basin 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 February 9, 2017, and shall be
subject to the following specified conditions and limitations:
I. 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. The drainage areas will be
limited to the amount of built -upon area indicated on page 3 of this permit, and per
approved plans.
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 controls have been
designed to handle the runoff from 3.17 acres of impervious area.
3. 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 and permit.
4. The runoff from all built -upon area within the permitted drainage areas of this project
must be directed into the permitted stormwater control systems.
5. This permit covers the construction of a 45 home planned unit development with club
house and associated roads and parking.
Page 2 of 8
State Stormwater Management Systems
Permit No. SW7070127
6. The following design criteria have been provided in the wet detention pond and must be
maintained at design condition:
a. Drainage Area, acres:
b. Total Impervious Surfaces, ft2:
C. Design Storm, inches:
d. Pond Depth, feet:
e. TSS removal efficiency:
f. Permanent Pool Elevation, FMSL:
g. Permanent Pool Surface Area, ft2:
h. Permanent Storage Volume, ft3:
i. Permitted Forebay Volume, ft3:
j. Temporary Storage Elevation, FMSL:
k. Temporary Storage Volume, ft3:
I. Controlling Orifice:
M. Receiving Stream/River Basin:
n. Stream Index Number:
o. Classification of Water Body:
II. SCHEDULE OF COMPLIANCE
6.66
114,922
1.0
3.60
90%
0.60
16,355
45,281
8,241
2.10
27,935
2.50" � pipe
Scuppernong River/Pasquotank
30-14-4—(9)
"SC"
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 times provide the operation and maintenance necessary to
assure the permitted stormwater system functions at optimum efficiency. The approved
Operation and Maintenance Plans 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 revegetation 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 bypass structure, filter media, flow spreader,
catch basins, piping and vegetated filter.
g. A clear access path to the bypass structure must be available at all times.
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.
Page 3 of 8
State Stormwater Management Systems
Permit No. SV 7070127
5. The facilities shall be constructed as shown on the approved plans. 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.
6. 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.
7. 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.
8. Access to the stormwater facilities shall be maintained via appropriate easements at all
times.
9. 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.
10. The permittee shall submit final site layout and grading plans for any permitted future
areas shown on the approved plans, prior to construction.
11. 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.
12. 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.
13. This permit shall be effective from the date of issuance until February 9, 2017.
Application for permit renewal shall be submitted 180 days prior to the expiration date of
this permit and must be accompanied by the processing fee.
14. 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.
Page 4 of 8
State Stormwater Management Systems
Permit No. SV 7070127
15. Prior to 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.
16. 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 SW7070127, 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. Construction of additional built -upon area in excess of 3.17 acres, as shown on
the approved plans, will require a permit modification.
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 basin. Lots that will naturally drain into the system are not
required to provide these measures.
h. Filling in or piping of any vegetative conveyances (ditches, swales, etc.)
associated with this development, except for average driveway crossings, is
strictly prohibited by any persons.
i. A minimum 30' wide vegetated buffer area shall be provided between surface
waters and all impervious surfaces.
17. 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.
18. 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.
Page 5 of 8
State Stormwater Management Systems
Permit No. SV 7070127
III. GENERAL CONDITIONS
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.
2. 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 reissuance 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. 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.
9. The permittee shall notify the Division any name, ownership or mailing address changes
within 30 days.
Permit issued this the 9th day of February, 2007.
NORTH CAROLINA ENVIRONMENTAL MANAGEMENT COMMISSION
for
Alan W' Klimek, P.E., Director
Division of Water Quality
By Authority of the Environmental Management Commission
Permit Number SW7070127
Page 6 of 8
State Stormwater Management Systems
Permit No. SV 7070127
The Village at Columbia
Stormwater Permit No. SW7070127
Tyrrell County
Designer's Certification
I, , as a duly registered in the
State of North Carolina, having been authorized to observe (periodically/ weekly/ full time) the
construction of the project,
(Project)
for (Project Owner) hereby state that, to the best of
my abilities, due care and diligence was used in the observation of the project construction such
that the construction was observed to be built within substantial compliance and intent of the
approved plans and specifications.
The checklist of items on page 2 of this form is included in the Certification.
Noted deviations from approved plans and specification:
Signature
Registration Number
Date
SEAL
Page 7 of 8
State Stormwater Management Systems
Permit No. SV 7070127
Certification Requirements:
1. The drainage area to the system contains approximately the permitted acreage.
2. The drainage area to the system contains no more than the permitted amount'of
built -upon area.
3. All the built -upon area associated with the project is graded such that the runoff
drains to the system.
4. All roof drains are located such that the runoff is directed into the system.
5. The bypass structure elevations are per the approved plan.
6. The bypass structure is located per the approved plans.
7. A Trash Rack is provided on the outlet/bypass structure.
8. All slopes are grassed with permanent vegetation.
9. Vegetated slopes are no steeper than 3:1.
10. The inlets are located per the approved plans and do not cause short-circuiting of
the system.
11. The permitted amounts of surface area and/or volume have been provided.
12. All required design depths are provided.
13. All required parts of the system are provided.
14. The required system dimensions are provided per the approved plans.
cc: NCDENR-DWQ Regional Office
Tyrrell County Budding Inspections
Page 8 of 8
USE; ONLY:''_74w� , "'i" �ri`�'-ro.aUts ohs � 'ti?5;ti "; . ✓-'✓'..:r" 7: v;ay
Date Received
Fee Paid
Permit Number
a
n
State of North Carolina 6WAr—y-
Department of Environment and Natural Resources �G��VEU
Division of Water Quality
BAN 2 4 209TORMWATER MANAGEMENT PERMIT APPLICATION FORM � \
This form may he photocopied for use as an original
[)WQ-WARO
I. GENERAL INFORMATION
1. Applic.a.�nts�name (specify the name of the corporation, individual, etc. who owns the project):
t11� U: LIAt(� a� �O�tAmbt�G LL•C�
2. Print Owner/Signing OfJ(icia ' name and titles (person legally responsible for facility and compliance):
3. Mailing Address for person list in item 2 above:
City: �j tGt/P%lh l�i lIQ- State:_ D Zip: I 1p 6 b
Telephone Number. h 121 Ce ( t A-4-3 -jk-z Tj 1 Z7
FA ek i -15-7 o 3 3 1
4. Project Name (subdivision, facility, or establishment name - should e consistent with project name on plans,
specifications, letters, operation and maintenance agreements, etc.):
5. Location of Project (street address):
11
City: C 01J 1'e' Nr , County:
6. Directions to project (from nearest major intersection)
F- om Colt nb.A Zyo, 4c 14- I�- f3 n T-a +c, 4k n -of t�G`j�
S% 130o Z 01 5 c i-i, Crrkc .jam ri'4 {- or,
t6 t3so F+. Ser}�I t li
7. Latitude: 5°- 54- L 4'- t 3Longitude: wig ld - Z7 of project W Cj1J 8�
8. Contact person who can answer questions about the project:
Name: n (-4','OD Telephone Number: (25Z ) 34I - 4S0
It. PERMIT INFORMATION:
1. Specify whether project is (check one): New Renewal Modification
Form S\VU-101 Version 3.99 Page 1 of
2. If this application is being submitted as the result of a renewal or modification to an existing permit, list the
existing permit number iJ i} and its issue date (if known)
3. Specify the type of project (check one):
_Low Density High Density _Redevelop _General Permit Other
4. Additional Project Requirements (check applicable blanks):
_CAMA Major i�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.
III. PROJECT INFORMATION
1. In the space provided below, summarize how stormwater will be treated. Also attach a detailed narrative
(one t`o-t two pages)) describingstormwater management for the project.
V`tc+ DLk np nA
2. Stormwater runoff from this project drains to the
3. Total Project Area: ( O , 0:3 acres
River basin.
4. Project Built Upon Area: 2>5- 64 %
5. How many drainage areas does the project have? C- Lot Iav-Y ara:n {p A coin mom O
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.
BaStiih'Informauon,S4,',„ �1P
......:..caau..r__.....>�.2...._....._...e.TPw�_.....
fiin'4,`^DratriageAreall*n�'4?""`w
''z"'"'Dr'amageAi'ea2 e't''`.'""'t
—.. *,_-r,
Receiving Stream Name
r
o R�K•i t
Receiving Stream Class
Drainage Area
VD-0-3
Existing Impervious' Area
Proposed Impervious`Area
% Impervious` Area (total)
�.�� O - •53 I.53 -Z5
=
�.z,r r,,awIm
pewious Surface Area
& `--: B `4� rama e,9f6b4l't"`.� re
' x.yr8 "r^D�ama e'F�rea2 "`'a'"D:
g
On -site Buildings
Z
On -site Streets
On -site Parking
On -site Sidewalks
o
Other on -site
12 I ZO
JAC
qrr-site I
3ZD
1�
Total: I Z '!
Total: �2
Impervious area is defined as the built upon area/including, but not limited to, buildings, roads, parking areas,
sidewalks, gravel areas, etc.
PW4
Form SWU-101 Version 3.99 Page 2 of 4
7. How was the off -site impervious area listed above derived?�yr4
t _
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.
2. No more than square feet of any 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 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 (919) 733-5083 for the status
and availability of these forms.
L�orm 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
Jan 22 0; 02t28p Emploaee 252-355-8186 p.2
VI. SUBMITTAL REQUIREMENTS
Only complete application packages will be accepted anti 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 tho appropriate DWQ Regional Office.
1, I lea w indicate that you have provided the, following required informat inn by initialing in the space proviced
nrxi to each item.
Initials
• Original and one ropy of the. Stnnnwatcr MmwgOmout Yennit Application Forrn
• One Copy Or the applicable Supplement Form(n) for each BMP --
• Permit application processing fee of $420 (payable to NCDF.NR)
• Detailed narrotive cirscript ion of slormwa ter it atmeut/managomanl
• Two copies of plans and specifications, inrlurlinp:
- Development/project [wino
- Engineer coil firm
.. lc}rend
North at row
SmIr.
Revision number k rlmn
- Mean high water line
Dimensioned pruperly/project lx,undary
1,mation map with namerl streets or NCSR numbers
Original arntoun. proposed contours, sent elevations, finished Roar elevations
- Details of reads, drainage fcatm'es, collection syste.ms, and stormwatcr control measure-%
Wetlands delineated, or a note On plans that rune exist
Existing drainage (including offmte), rlminage Casenunts, pipe sizes, runolf calculntions
- Drainage areas delineated
- Vel;Otatod huffOrs (when` required)
VIf. AGENT AUTHORIZATION
ll' you wish to designaw authority to another individual or form so that they may piuvide information on your
behalf', please complete this sctitiun.
ncsi_,oalcd at;nm (individual or Rrm):,
City: Slate: Zip: .. ..
Phone: ( I Fax: ( ) ... ...__.......
Vill. APPLICANT'S CERTIFICATION
1, (print or (Y1x.- riamc of person 11.51txl in General Information. Item 2)
cerlily that the lofurmaliun included on this permit appllcaliuu furor is, to the. Wst of my knowledge. corrort and
that the project will he constructed in conformance with the. apprnverl Plans, that the required deed restrictions
and proteclivr rovennnis will be recorder], and that the. proposed projem romplics with the requirements of 15A
NCAC 21-1 .1000.
Signature: V/ L c 114C I vlc y/y8/A/ Z e� 17
/Gy�E /-etrs6
Forin SWU.101 Vcrsion 3.99 Page4of4
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Refer to this list of items to make sure all necessary documents are
part of the SW application package
A complete package includes all of the items listed below.
Initials
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
Detailed narrative description of stormwater treatment/management
Two copies of plans and specifications, including: p'�
- Development/Project name p2rr- N �l ED
- Engineer and firm
- Legend
- North arrow
JAN 2 4 2007
- Scale �p�/�
- Revision number & date E)WQ-WARD
Nf}- Mean high water line
f [.6T - 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
In Ck�c5 - Drainage areas delineated
NPr - Vegetated buffers (where required)
Permit No. W ``O ! a .2 9
(to be provided by DWQ)
�������� State of North Carolina
Department of Environment and Natural Resources
JAN 2 4 2001 Division of Water Quality
STORMWATER MANAGEMENT PERMIT APPLICATION FORM Of
DVVQ-INARO
WET DETENTION BASIN SUPPLEMENT
This form may be photocopied for use as an original
DWO 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:
Contact Person:
For projects with multiple basins,
elevations
Basin Bottom Elevation
Permanent Pool Elevation
Temporary Pool Elevation
r•hy Phonc Number: (L57-) 341 41503
which basin this workshect applies to: p tJ L
—3.O ft.
(floor of the basin)
(elevation of the orifice)
(elevation of the discharge structure overflow)
areas
Permanent Pool Surface Area (�7D sq. ft. (water surface area at the orifice elevation)
Drainage Area —(•Z ac. (on -site and off -site drainage to the basin)
Impervious Area ac. (on -site and off -site drainage to the basin)
volumes
Permanent Pool Volume
Temporary Pool Volume
Forebay Volume
Other parameters
SA/DAI
Diameter of Orifice
Design Rainfall
Design TSS Removal 2
2 cu. ft. (combined volume of main basin and forebay)
c? 3� cu. ft. (volume detained above the permanent pool)
cu. ft. (approximately 20% of total volume)
(surface area to drainage area ratio from DWQ table)
a • S in. (2 to 5 day temporary pool draw -down required)
in.
2 % (minimum 85% required)
Form SWU-102 Rev 3.99 Page I of 4
Footnotes:
1 When using the Division SAIDA 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.
II. 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
T 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.
T c. The temporary pool controls runoff from the design storm event.
7Prj d. The temporary pool draws down in 2 to 5 days.
04 ( e. If required, a 30-foot vegetative filter is provided at the outlet (include non -erosive flow
1 }� calculations)
IVD -A G4 ahF: The basin length to width ratio is greater than 3:1.
`(T 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.
DI 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.
_�t. ,M D 7fT m. A mechanism is specified which will drain the basin for maintenance or an emergency.
IIl. 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 r(does not incorporate a vegetated filter at the outlet.
This system (check one) 0 does does not incorporate pretreatment other than a forebay.
Form SWU-102 Rev 3.99 Page 2 of 4
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.
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 e2�_ feet in the main pond, the sediment shall be removed.
When the permanent pool depth reads
Sediment ReEteation
l EL
Bottom 3
FOREBAY
191, feet in the forebay, the sediment shall be removed.
BASIN DIAGRAM
Ull in the blanks)
Permanent Pool Elevation ()-e
Sediment Removal Elevation 75%
Bottom Elevation —.Z, 25%
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.
Fonn SWU-102 Rev 3.99 Page 3 of 4
Jan.22 O'i 02:28p Employee 252-355-0186 p.3
7. All components of the wet detention basin system shall he maintained in good working order.
I acknowledge and agree by my signature below 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. /��y 1 6 7/
Print
0
_ .-.
Address: `tea 1 0� ✓ W d� „� �vin r i 5 iP v� �� S V 1 c Vti D Z l U G Ct_
Phone
Signature:
Date:
Note: Thu legally responsible parry should nut be a homeowners association unlass more than SIN% ol'the lots have been sold and a
hlsidcat ol'tho subdivision has been named the president.
I, ` 1`1 t h �^ a Notary Publli , for the Statc of _M. 0
County of Uif PVl f t n of da he eb certify that. n-, `f V1 .__ .�., ✓ d f �t rC Yl
rc
personally appeared before me this c ay of h� p?CY1 i , and acknowledge the duc
execution of the forgoing wet detention basin maintenance retlui nls. Witness my hand and otiicial seal,
SEAL
My commission expires
..j0.: 9--16
R"I SWII-102 Rev 3.94 Page 4ol'A
' .';I .
'I" . (. . , T ..IC;Wi p " _ I 'I. 1,,, I � .l_ I.I 'AI'I :.t. )i� I1 .
Fuss & O'Neill, Inc.
January 23, 2007
Page 1
The Village at Columbia, LLC
Built -upon Area
Unit
Description
No. of
Size in
Units
SQFT
Roadway
2275 20
Cape Cods
4 1,184
Rancher
41 1,698
Club House
1 825
Pool
1 320
Driveway Allowance
47 360
Total Built -Upon Surface Area (SQFT)
Total Built -Upon Surface Area (AC)
Total Site Acerage
WetlandAcerage
Built Upon Area
Total
SQFT M;/ovlf b
45,500 jrveQ gw� ° re �t s�
4,736 (/
69,621
825
320
16,920
137,922
3.17
10.03
1.53
35.64%
Example Calculation for Illustration Purposes:
10 acre site
6 acres of wetlands
1.5 acres of impervious surface
% Impervious = 1.5 AC Impervious/ (6Ac X 0.25) + 4 AC Uplands = 23.1 % impervious.
t OQ A
)I " 17480 it
rrrrmr� taw
NC SR 1300 The Village at Columbia Page 1 of 4
Columbia, NC Narrative and Calculations
Prepared by Fuss O'Neill, Inc.
This submission is a fast track permit application for Village at Columbia. The Seasonal High Water Table is within 4-6 inches of the ground
surface according to Jason Godwin a soil scientist with our office who visited the site and performed soil angering to obtain soil coloration to
determine the SHWI' by the presence of iron oxides. In light of this finding, we have investigated measures not dependent upon inflitraion for
function and in consulted with the Owner. The Owner selected the wet -detention method based upon input from us. The wet detention pond is
to be set with the permanent pool at the approximate water table and all of the stormwater pool is above that depth.
Wet Detention Pond Sizing
We used Table 3.3-3 to size the wet detention basin for 90% TSS capture. The existing outfall is a railroad side ditch to the east of the property. brace uns
side ditch is not available to us for modification/maintenance the basin is designed for 90% capture so that the grass -lines swale outlet is not required. The
basin size includes all of the impervious surface of the site. The SA to DA ratio is interpolated based upon the weighted average depth of the the detention
basin. The weighted average was determined using the depth times area for each increment of surface area for each contour of the proposed grading plan for
the basin.
Select Wet Pond
Required
Normal Pool
Area -
SA/DA Ratio
Acreage
Surface Area
Length
Width
esign
(In Percent)
Required (Sq-
Depth)
th
Ft
Table 3.3-3 Interpolation Based
30%/3.5-Ft Depth
3.00%
7.20
9,409 Sq-Ft
NA NA
upon Average Depth - See Below
Table 3.3-3 Interpolation Based
400/o/3.5-Ft Depth
4.00%
7.20
12,545 Sq-Ft
NA NA
upon Average Depth - See Below
Interpolate for
3.%/° °
7.20
1 ],178 Sq-Ft
NA NA
Table 3.3-3 Interpolation Based
upon Average Depth - See Below
35.64%BUA
Depth of
Storm Volume
Runnoff
Site Area in
Required (Cu-
Captured
Square Feet
Ft)
(Inches)
1
313,632
126,136 Cu-Ft
N:\p2006\501-1he Village at Columbia\Info & Calculations\Columbia Wet Detention Pond.xls
NC SR 1300 The Village at Columbia Page 2 of 4
Columbia, NC Narrative and Calculations
Prepared by Fuss O'Neill, Inc.
Volume Divided by Surface Area =
2.34-Ft
wie. r%o.e..9-- n,, 1 r,F it. \Y/ofcr C„rfarc Vcrc„c Stnrnor and Snrfaee Area Includinp' Forebav
Incremental
Contour
Depth to
Incremental
Cumulative
Surface Area
Cum ulative
Comment
Elevation
Description
SA (Sq-Ft)
Normal Pool
Volume (Cu-
Total Volume
Increase (Sq-
Storm Volume
Ft)
(Cu-Ft)
Ft)
-3
Empty
9,502
3.6
0
0
NA
NA
-2
11,090
2.6
10,296
10,296
1,588
NA
-1
12,833
1.6
11,962
22,258
1,743
NA
0
14,625
0.6
13,729
35,987
1,792
NA
0.6
Normal Pool
16,355
0.0
9,294
45,281
1,730
0
1
17,509
-0.4
6,773
52,054
1,154
6,773
2
20,649
-1.4
19,079
71,133
3,140
25,852
2.1
Temporary Pool
21,012
-1.5
2,083
73,216
363
27,935
Greater than
Required Storm
3
24,283
-2.4 -
20,383
93,599
3,271
48,318
Volume Sufficient
for the First 1-inch
Comment
Contour
Elevation
SA (Sq-Ft)
Depth to
Normal Pool
Incremental
Volume (Cu-
Ft)
Cumulative
Volume (Cu
Ft)
Incremental
Surface Area
Increase (Sq-
Ft)
Cumulative
Storm Volume
-3
Empty
1,395
4
0
0
NA
NA
-2
1,704
3
1,550
1,550
309
NA
-1
2,076
2
1,890
3,440
372
NA
0
1 2,427
1
2,252
5,691
351
NA
1
Normal Pool
3,511
0
2,969
8,660
1,084
0
2
4,097
-1
3,804:
12,464
586
3,804
3
Temporary Pool
4,777
-2
4,437
16,901
680
8,241
Percentage of
Total Volume
17%
Check
27,935
41,545
18.1%
N:\p2006\501-The Village at Columbia\Info & Calculations\Columbia Wet Detention Pond.xls
NC SR 1300
Columbia, NC
Prepared by Fuss O'Neill, Inc.
The Village at Columbia
Narrative and Calculations
Storm Water Management Low Flow Outlet
The low flow outlet is designed to release the first inch of runoff within 2-5 days of the ru moff event.
A group of orifices will be used to perform this function and they will be provided in the flash board or the principal spillway.
l•t= VQ A A A L lY "'.D A INLLIRoer or Vruiuc:
Maximum
Average
N (No of
1
-.Orifices):1
Cd'
'; 0 65
0:65?:
Diametei
"•.2 5
2 5.` ,
nches
Area(Square
0.03409
0.03409
Feet
Water Depth
_ -
Average Head
0.698
0.323
(Feet)
cfs
0.148548267
0.101044117
Volumc To
27,935
27,935
Drain Cu-Ft
Time To
2.18
3.20
Drain (Days)
25%Volume 387
50% Volume 775
Page 3 of 4
N:\p2006\501-The Village at Columbia\Info & Calculations\Columbia. Wet Detention Pond.xrs
NC SR 1300 The Village at Columbia
Columbia, NC Narrative and Calculations
Prepared by Fuss O'Neill, Inc.
Principle Spillway - Sharp Crested Weir
Drainage Area =10.03 Ac
Q10 = 0.5 X 3.9 in/hr X 7.2 AC =14cfs
Q100=0.5X5.8in/hrX7.2AC=21 cfs
The principle outlet will be a sharp crested weir.
Downstream of the weir, the concrete flume may be modelled based upon Manning equation for open channel flow.
Qw=3.3XLXH^1.5
QW L H Q-Check Flood Stage
14 8 0.66 14.0 2.76
21 8 0.86 21.0 2.96
Mannings equation as calculated using a Field's Wheel hand calculator.
Manning's Equation for a 36-inch Pipe at 0.2%. Slope and a Mannings N for Concrete of 0.013 yields a capacity of 30 cfs, which i,
ent for the 100-year flood.
the discharge is captured by the wier, the box itself will function as an improved inlet and therefore, the weir controls this design.
Page 4 of 4
N:\p2006\501-1-he Village at Columbia\Info & Calculations\Columbia Wet Detention Pond.xls