SW8040323_HISTORICAL FILE_20041014

STORMWATER DIVISION CODING SHEET
POST -CONSTRUCTION PERMITS
PERMIT NO.
SW8 O`} p 323
DOC TYPE
❑ CURRENT PERMIT
❑ APPROVED PLANS
HISTORICAL FILE
❑ COMPLIANCE EVALUATION INSPECTION
DOC DATE
'ZoOLAiDIy
YYYYMMDD

�OFWATF9Q Michael F. Easley, Governor
�O G William G. Ross, Jr., Secretary
01
7 North Carolina Department of Environment and Natural Resources
O Y Alan W. Klimek, P.E. Director
Division of Water Quality
October 14, 2004
Mr. Jon Vincent, Member/Manager
Tri-Coast Properties, LLC
1508 Military Cutoff Road, Suite 302
Wilmington, NC 28403
Subject: Approved Plan Revision
Shallotte Shops
Stormwater Project No. SW8 040323
Brunswick County
Dear Mr. Vincent
On July 19, 2004, the Wilmington Regional Office received a plan revision for
Stormwater Management Permit Number SW8 040323, Shallotte Shops, located at
4501 Main Street in Shallotte, NC. The revisions include the reduction in overall built -
upon area due to the deletion of a building, and the reconfiguration of the parking
area. The remaining built -upon area of 10,891 square feet has been set aside for
future development. It has been determined that a formal permit modification is not
required for the proposed changes. We are forwarding you an approved copy of the
revised plans for your files. Please replace the old approved plan sheet with the new
one, and replace the old page 2 of the application with the new one, enclosed.
Please be aware that all terms and conditions of the permit issued on April 12, 2004,
remain in full force and effect. Please also understand that the approval of this
revision to the approved plans for the subject State Stormwater Permit is done on a
case -by -case basis. Any other changes to this project must be approved through this
Office prior to construction.
If you have any questions concerning this matter, please do not hesitate to call me at
[phone].
Sincerely,
Linda Lewis
Environmental Engineer
RSS\arl: S:\WQS\STORMWAT\REVISION\040323.oct04
cc: Mike Hoffer, Tripp Engineering
Town, of Shallotte Building Inspections —..�.
Linda' Lewis
W ilmi ngton-Regional Office
Centfal Files
North Carolina Division of Water Ci ity 127 Cardinal Drive Extension Phone [phone] Customer Servicel-877£23-6748 Wilmington Regional Office :' Wilmington, NC 28405-3845 FAX [phone] Internet: h2o.encOnestate.nc.us NorthCarolina
An Equal Opportunity/Affirmative Action Employer— 50% Recycled110% Post Consumer PaperNaturally

If this application is being submitted as the result of a renewal or modification to an existing permit, list
The existing permit number 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.
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 will be treated with wet detention
2. Stormwater runoff from this project drains to the Cape Fear River basin.
3. Total Project Area: 2.04 acres
5. How many drainage basins does the project have? 1
4. Project Built Upon Area: 72.2 %.
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.
Basin+`,Information air ;,y
<.
K t Dr'aina a Basm`1 ' v
k. g
p y , $Drainage Basin 2e ;
Receiving Stream Name
Shallotte River
Receiving Stream Class
SC HQW
Drainage Basin Area
2.04 ac
Existing Impervious * Area
-
Proposed Impervious * Area
1.47 ac
% Impervious* Area (total)
72.2%
Impery�ous�aSurface Area r
IDrainage BastnLr�''`'
Y''��*q 'kDramageBasin 2 °"y
On -site Buildings
11,286 sf
On -site Streets
-
On -site Parking
39,200 sf
On -site Sidewalks
2,650 sf
Other on -site (future)
10,891 sf
Off site
Total:
E=64,027 sf
E_
* Impervious area is defined as the built upon area including, birt not limited to, buildings, roads, parking
areas sidewalks, gravel areas, etc.
Form SWU-101 Version 3.99
Page 2 of 4

2. If this application is being submitted as the result of a renewal or modification to an existing permit, list
The existing permit number 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 _ 404H401 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 will be treated with wet detention
2. Stormwater runoff from this project drains to the Cape Fear River basin.
3. Total Project Area: 2.04 acres
5. How many drainage basins does the project have? 1
4. Project Built Upon Area: 72.2 %.
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.
Basin Information
Drainage Basin 1
Draiiage Basin 2
Receiving Stream Name
Shallotte River
Receiving Stream Class
SC HQW
Drainage Basin Area
2.04 ac
Existing Impervious * Area
-
Proposed Impervious * Area
1.47 ac
% Impervious* Area (total)
72.2%
"Ihipervious *`Surface'Area "
I Drainage Basin'l '`
'Drainage Basin 2
On -site Buildings
10,032 sf
On -site Streets
-
On -site Parking
43,480 sf
On -site Sidewalks
3,016 sf
Other on -site (future)
7,499 sf
Off -site
-
Total:
E=64,027 sf
E=
* 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

Shallotte Shops
Subject: Shallotte Shops
From: Linda Lewis <[e-mail]>
Date: Thu, 30 Sep 2004 11:40:02 -0400
To: Michael Hoffer <[e-mail]>
Mike:
Forget about the permit modification. I found a condition in the original permit
that requires that any future development areas be permitted prior to development,
so we are covered. I still need a revised page 2 of the application, though.
Thanks,
Linda
1 of 1 10/4/2004 3:59 PM

nShallotte Shops SW8 040323
Subject: Shallotte Shops SW8 040323
From: Linda Lewis <[e-mail]>
Date: Thu, 30 Sep 2004 11:09:44 -0400
To: Michael Hoffer <[e-mail]>
Mike:
Good news! I found the file with your plan revision (aka modification) attached.
Please send in (fax is fine) a revised page 2 of the permit to reflect the changes
in the distribution of the BUA. The building and parking amounts have decreased,
and you have provided for a future amount that was not there before.
I haven't determined yet if the permit needs to be rewritten to reflect the future
BUA since none was originally accounted for. I'll,have to get back to you on that.
Please go ahead and send in the revised page 2. If I need to rewrite the permit,
I'll request the modification fee at a later date.
Thanks, Linda
C
S
I of 1 10/4/2004 3:59 PM

„_
TRIPP ENGINEERING, P.C.
4iW Chestnut street
Wilmington, North Carolina 28401
Phone: [phone] • FAX: [phone]
July 16, 2004
NCDENR
Division Water Quality
127 Cardinal Drive
Wilmington, NC 28405-3845
Attn: Ms. Laurie Munn
Re: Shallotte Shops
Project No. SW8 040323
TE 03128
Dear Laurie:
JUL 1 q 2004
I'm writing to request a modification to existing permit No. SW8 04023. Due to
town zoning requests and fire marshal concerns, the rear building has been removed from
the site plan, and the parking areas reconfigured accordingly. Also, the property lines
have shifted.
Please note that the drainage area, impervious surfaces and pond dimensions have
not changed. All of your original concerns remain addressed and the outfall location is
unchanged. Revised calculations and narrative are attached.
Please review for approval and contact us with any questions, comments or if you
need additional assistance. Thank you.
Sincerely,
Tripp Engineering, P.C.
01. . �, �14
Michael Hoffer
MBH:dcb
Enc.

07/13/04
Stormwater Narrative
Shallotte Shops
Brunswick County, NC
TE03128
Shallotte Shops is a 2.04-acre existing vacant tract proposed for a commercial shopping center.
Impervious areas include 11,286 SF of building, 2,650 SF of sidewalk and 39,200 SF of asphalt.
10,891 SF is allocated for future impervious area, creating a total lot impervious area of 64,027
SF. The total percent impervious is 72.2%.
The project will be treated by wet detention. The detention pond will be designed to meet the
State's P and the County's I0-year pre -post requirement. Outflow from the pond drains to the
Shallotte River, classification SC HQW.
RECEIVED
JUL.19 2004
pit. 5004v3Z3

7/13/2004 Shallotte Shops 03128
MBH Stormwater Calculations
Total Draina e Area
s . ft. acres
88,652 1 2.04
Impervious Area
Land Use
sq. ft.
acres
buildings
11,286
0,26
asphalt
39,200
0.90
concrete
2,650
0.06
future
10,891
0.25
Tota I
64,027
1.47
Stormwater Calculations:
Time of Concentration
Hydraulic Length (L) = 630 ft.
hange in Height (H) = 4 ft.
TO = (L, /H).Jeo / 128
= 7.84 min.
Flow for 10 year, 6 hour Storm (Qjo)
QPRE _ (CPRE) x (110) x (Area)
= 3.21 cfs
QPosT = (CPosT) x (1i0) x (Area)
9.74 cfs
Detention Pond Design:
Pond Size:
Elevation
(ft.)
Surface Area
(Sq. ft.)
Normal Pool
31.00
4,615
Flood Pool
32.10
51710
Top of Bank
35.00
7,988
Bottom of Pool
26.00
254
Total Provided Storage Volume:
Vol. _ [(Normal pool SA + Flood Pool SA) / 2]
x (F.P. elev - N.P. elev.)
5,679 cu.ft.
% impervious = 0.722
= 72.2%
say 73.0%
CPRE = 025
CPOST= (% imp .)(.95)+(1%imp.)(.25)
= 0.76
lio = 6.30 in/hr
log = 7.79 in/hr
Flow for 50 year, 6 hour Storm (Qso)
QPRE _ (CPRE) x (110) x (Area)
= 3.96 cfs
QPosT= (CPOST) x (I,0) x (Area)
= 12.05 cfs
State Surface Area Requirement at normal pool
Pond side slopes = 3 :1
Depth below N.P. = 5 ft.
SA/DA = 0.0444
(Chart for 90% TSS Removal for Wet Detention
Pond without Vegetative Filter)
Required SA = (SA/DA) x (Total Drainage Area)
3,936 s . ft.
State Volume Requirement for Storage of first 1" runoff:
Rv = .05+.009(Percent Impervious)
0.7000056 in/in
= 5171 cu.ft.
C A R p �xxliz
RECEIVED
;QO oy;
JUL 112004 = a SEAL
y; t»�a •'a
DWQ
lljF�GI NEQ �Q
PROD# S��,gogo323 ��iii �REGOA o`
y
°j�7nnnnnnta`0�
of
03128-Pond 1 of 2

7/13/2004
MBH
Pond Volume:
Bottom SA = 254 sq. ft
Normal Pool SA = 4,615 sq. ft.
Vol. _ [(N.P. SA+ Bott,
= 12,173 cu.ft.
Forebav:
Required Volume
Vol. = 20% of storage volume
2,435 cu.ft.
Provided Volume
Shallotte Shops
Stormwater Calculations
171QNSM-!
bottom SA = 300 sq, ft.
Normal Pool SA = 1,430 sq. ft.
Vol. _ [(N.P. SA + Bottom SA) / 2] x (N.P. el. - Bottom el.)
= 2,595 cu.ft. I
= 3 ft.
Outlet Structure Design:
Flow for 2-day drawdown:
for 1st 1" of stormwater,
Q = Required Vol. /172,800 sec. (2-days
0.030 cfs
nequirea Area or Hipe Tor 2-dav drawdown
A= Q/ [Cd x SQRT(2 x g x h)]
Cd = 0.6
g = 32.2 ft./sz
h = (F.P. elev.- N.P. elev.) /2
0.55 ft.
A = 0.0084 sq. ft.
Diameter of Pipe for 2-dav drawdown
DIA. = SQRT[(A x 4) / pi]
0.1033 ft.
1.24 in.
Use 1.0" orifice
Outlet Structure Check:
Using a 4' x 4' Basin,
Perimeter (L) = 16 ft.
M
C = (% imp.)(95) + (1 % imp.)(25)
0.76
1 = 6.30 in. for a 10 yr. Storm
A = 2.04 Acres
9.74 cfs
Flow for 5-day drawdown:
7for 1st 1" of stormwater,
Q = Required Vol. /432,000 sec.(5-days)
= 0.012 cfs
megwrea Area or Hipe Tor J-dav drawdown
03128
A= Q/[Cd xSQRT(2xgxh)]
Cd =
0.6
g =
32.2 ft./sz
h = (F. P.
elev. - N. P. elev.) / 2
=
0.55 ft.
A = 0.0034 sq. ft.
Diameter of Pipe for 5-day drawdown:
DIA. = SQRT[(A x 4) / pi]
= 0.0653 ft.
= 0.78 in.
Q= CwxLxH
H= [Q/(CwxL]
Cw = 3
0.35 ft.
Peak elevation = flood pool elevation + H
= 32.45 ft.
03128-Pond 2 of 2