SW8011220_COMPLIANCE_20020830

STORMWATER DIVISION CODING SHEET
POST -CONSTRUCTION PERMITS
DOC TYPE ❑ CURRENT PERMIT
❑ APPROVED PLANS
❑ HISTORICAL FILE
LeD COMPLIANCE EVALUATION INSPECTION
DOC DATE-
YYYYMMD

August 30, 2002
Stormwater Narrative
Jordan Tract
New Hanover County, NC
TE 01048
Jordan Tract is an existing 6.69-acre single-family residential lot. The townhome complex
will provide street access and 24 units. Stormwater runoff will be treated by wet detention
to meet the state's 1" and the County's 25-year pre -post requirements.
The 24 units will create a built upon area total of 48,152 sf. Street and parking impervious
of 67,082 sf bring the total project built upon area to 39.6% impervious. Impervious areas
will be treated by wet detention and discharged to an unknown tributary of Smith Creek
classified C-SW.
RECEIVED
AUG 3 0 2002
DWQ
PROD# 5W� Of 12ZO

8/28/2002
CDC
Total Drainage Area
s . ft. acres
291,294 6.69
Impervious Area
Land Use
sq. ft.
acres
buildings
48,152
1.11
arkin !as halt
67,082
1.54
Total
115,234
2,65
Stormwater Calculations:
Timo of Concentration:
Hydraulic Length (L) = 1,300 ft.
change in Height (H) = 4.5 ft.
Tc = (L' 1H)" 1 128
17,29 min.
Flow for 10 year, 6 hour Storm (010):
QPRE _ (CPRE) x (tto) x (Area)
10.53 cis
QPosT = (CPosr) x (110) x (Area)
22.33 cis
sou storage uapacity for 1u year storm:
CN = (98)(% imp.) + (45)(1-% imp.)
66
P = 4.82 in. fort Oyr, 5 hr storm
S = 10001CN - 10
Depth (D)= [P-(0.2)(S)]2 ! [P+(0,8)(S)]
= 1.61 in.
Time to Peak Flow:
TP = [(43.5)(D)(Area)] ! Q2 Posr
20.93 min.
Detention Pond Desi nT
Pond Si7a-
Elevation
(ft.)
Surface Area
((sq. ft.
Normal Pool
17.00
6,660
Flood Pool
18.50
10,218
Top of Bank
22,00
15,782
Bottom of Pool
11.00
20
Provided Storage Volume:
Vol. _ [(Normal pool SA + Flood Pool SA) / 2]
x (F.P. elev. - N.P. elev.)
12,659 cu. M.
RECEIVED
AUG 3 0 2002
DWQ
PROD 0 SW $0 1 1 Z 24
Jordan Tract
Stormwater Calculations
I [ It !l1177
oNk CAR01 %
�:o��'s5o�tiq
:a SEAL
?, 17374
l GINF..Q' Q
!'
��''�ii���GREGO
! 1ii1
% impervious = 0.396
= 39.6%
say 40.0%
CPRE = 0.25
CPosT = (% imp.)(.95)+(1-0/a imp.)(.25)
- 0.53
li0 = 6.30 in/hr
125 = 7.13 in/hr
Flow for 25 year, 6 hour Storm (Q25):
QPRE _ (CPRE) x (125) x (Area)
- 11.92 cfs
QPosT = (CPoST) x 025) x (Area)
25.27 cfs
Soil Storage Capacitv for 25 vear Storm:
CN = (98)(% imp.) + (45)(1-% imp.)
66
P = 5.71 in. for 25 yr, 6 hr storm
S= 10001CN-10
= 5.15
Depth (D)= fP-(0.2)(S)]` / [P+(o.a)(S)]
- 2.23 in.
Time to Peak Flow;
TP = ((43.5)(D)(Area)] 1 010,POST
- 25.64 min,
State Surface Area Re uirement at normalpool:
Pond side slopes = 3 :1
Depth below N.P. = 6 ft.
SAIDA = 0.0210
(Chart for 90% TSS Removal for Wet Detention
Pond without Vegetative Filter
Required SA = (SA/DA) x (Total Drainage Area)
6,117 s , ft.
State Volume Required for Storage of first 1" of runoff:
Vol, _ [(1/12) x (DA) x (% imp.)] +
[(1I12) x (DA) x (1-% imp.) x Cl
C = 0.2
12.537 cu. ft.
01048
RECEIVEII
AUG 3 0 2002
DWQ
PROM #
01048POND
1 of 2

8/28/2002 Jordan Tract 01048
CDC Stormwater Calculations
Pond Volume;
Bottom SA = 20 sq. ft.
Normal Pool $A = 6,660 sq. ft.
Vol. _ [(N.P. SA + Bottom SA) 1 2] x (N.P. el. - Bottom el.)
18,370 cu. ft.
Forebay:
Required Volume
Vol. = 201k of total permenant storage volume
3,674 cu, ft.
Outlet Structure Design:
Flow for 2-day drawdown:
for 1st V of stormwater.
Q = Required Vol. 1172,800 sec. (2-days)
0,073 cfs
Required Area of Pipe for 2-day drawdown:
A= Q 1(Cd x SQRT(2 x g x h))
Cd = 0.6
9. 32.2 ft.1s'
h = (F,P, elev,- N,P. elev.) 12
= 0,75 ft.
A = 0,0174 sq. ft.
Diameter of Pipe for 2-dav drawdown:
DIA. = SQRT[(A x 4) ! pi]
0.1488 ft,
1.79 in,
'Use: 1.5 in diameter pipe
Outlet ructure Check:
Using a 4' x 4' Basin,
Perimeter L = 16 ft.
Q = CIA
C + (1-% imp)(25)
0.53
1 = 7.13 in, for a 25 yr. Storm
A = 6,69 Acres
25.27 cfs
Q= CwxLxH'5
H = (Q 1 (Cw x L)]v"
Cw = 3
Peak elevation = flood pool elevation + H
19,15 ft.
Provided Volume
Bottom SA = 345 sq. ft.
Normal Pool SA = 2,234 sq, ft.
Vol. _ [(N.P. $A + Bottom SA) 1 2] x (N.P. el. - Bottom el.)
= 3.869 cu. ft.
depth = 3 ft.
Flow for 5-day drawdown:
for 1 st 1" of stermwater,
Q = Required Vol, 1 432,000 sec. (5-days)
0.029 cfs
Required Area of Pipe for 5-day drawdown
A= Q 1 ]Cd x SQRT(2 x g x h)]
Cd = 0.6
g = 32.2 ft.l52
h = (F.P. elev, - N.P. elev) 1 2
0.75 ft,
A = 0.0070 sq. ft.
Diameter of Pipe for 5-day drawdown:
DIA. = SQRT[(A x 4)1 pi]
= 0.0941 ft.
1.13 in,
01048POND 2 of 2

DETENTION POND ANALYSIS
FILE NAME-.
G:\DATA\WPDATA\WQS\POND101 1220.WK1
PROJECT#: SW8
011220
REVIEWER:
L. Lewis
PROJECT NAME-
Jordan Tract
DATE:
05-June-2002
Receiving Stream:
Smith Creek
Class:
C SW
Drainage Basin:
Cape Fear
Index No.
18-74-63
Site Area
5.86
acres
Drainage Area
-0"
f2q4' .0square feet
Area in Acre:
6.69 acres
IMPERVIOUS AREAS
Rational C
Buildings
48152.00
square feet
1.00
Road
50207,00
square feet
1,00
Parking Lots
16875,00
square feet
1.00
square feet
1.00
square feet
1.00
square feet
TOTAL
7:0:.0
1 square feet
Rational Cc= 0.52
SURFACE AREA CALCULATION
% IMPERVIOUS 39.56%
Des. Depth 6
TSS: 90
SA/DA Ratio 2.08%
Req. SA 6053 sf
Prov. SA sf..'I
VOLUME CALCULATION place a 1 " in the box if Rational is used
'
7i
Req. Volume .1�253cf
Prov. Volume 1259 Cf
ORIFICE CALCULATION
Avg. Head =
Flow Q2, cfs
Flow Q5, cfs
No. of Orifices
Diameter, inches
Drawdown =
160TOMAVA
Perm. Pool Volume= 18370
Req. Forebay Volume= 3674
Provided Volume= 3869.00
Percent=
SA@
Elevation=
0.72
ft
Q2 Area
0.073
cfs
Q5 Area
0.029
cfs
Orifice Area
Q=
ffidays
weir H x W
COMMENTS
Surface Area , Volume and Orifice are within Design Guidelines
2.56 sq. in.
1.02 sq. in.
1.77 sq. in.
0.050 cfs
in x in

December 10, 2001
Stormwater Narrative
Jordan Tract
New Hanover County, NC
TE 01048
Jordan Tract is an existing 5.86-acre single-family residential lot. The proposed improved
residential subdivision will provide street access and 18 single-family residential lots.
Stormwater runoff will be treated by wet detention to meet the state's 1" and the County's
25-year pre -post requirements.
Each lot will be allocated 3,000 sf of built upon area for a total of 54,000 sf. Along with
the street impervious of 44,320 sf, the total project built upon area will be 38.5%
impervious. Impervious areas will be treated with the wet detention pond and discharged
to an unknown tributary of Smith Creek classified C-SW.

EROSION CONTROL PLAN
FOR
156.80 AC f TRASK TRACT
Submitted By
Coastal Carolina Developers, Inc.
AREA TO BE DISTURBED: 138.0 Acres
Trask Tract is a 156.80 acre tract North of Gordon Road as shown on the vicinity map of the
erosion control plan.
The erosion on this tract will be controlled with undisturbed vegetative buffer zones as
indicated on the plan. In areas where there is evidence of erosion encroaching in to said buffer zones,
silt fence will be added immediately. Silt fences will be used at the toe of fills, if any.
In the event of any necessary temporary ditching, check dams wi11 be sized and installed to
contain 1800 cu.ft./acre of the area contributing to said temporary ditches.
Also enclosed in this plan are:
l . Construction sequence
2. Erosion Control Site Plan with...
a. Vegetation and seeding plan
b. Construction entrance
c. Silt fence
d. Temporary sediment traps
RECEIVED
APR 2 2 1997 1
ENGINEERING
DEPARTMENT
SCHEDULING OF WORK: Clearing and grubbing shall be scheduled and performed in
such a manner that subsequent grading operation and erosion control practices can follow
immediately thereafter. Excavation, burrow and embankment operations will be conducted such that
cuts and fills will be completed to final grades in a continuous operation. All construction areas not
otherwise protected shall be planted with permanent vegetative cover in accordance with the
Specifications within 30 working days after completion of active construction.

otherwise protected shall be planted with permanent vegetative cover in accordance with the
Specifications within 30 working days after completion of active construction.
MINIMUM AREAS TO BE DISTURBED: Only those areas necessary for timely and
proper completion of the project shall be stripped of native vegetation.
No land disturbing activity, except street crossings, shall be permitted in proximity to a natural
watercourse without a buffer zone along the margin of the watercourse of sufficient width to confine
visible siltation within the 25 percent of the buffer zone nearer the land disturbing activity.
The angle for graded slopes and fills shall be no greater than the angle which can be retained
by vegetative cover or other adequate erosion control devices or structures. Slopes left exposed will
within 30 working days of completion of any place of grading, be planted or otherwise provided with
ground cover, devices, or structures sufficient to restrain erosion
PLACEMENT OF SEDIMENT CONTROL DEVICES: All devices for sediment control
shall be constructed prior to beginning clearing and grubbing on site. The work includes the seeding
and grassing of the denuded areas. As soon as practicable after finish grades have been established,
all operations in connection with grassing shall be performed. If the grading work is completed in
the fall, all grassing shall be completed by September 30. If the grading work is completed in the
Spring, the grassing shall not be begun before April 15. Mulch shall be used where required for
stabilization of repaired areas. If vegetation has not stabilized the soil during the growth period
mentioned above, jute matting shall be installed on eroded slopes.
SEEDS: For fall planting, the grass seed shall be unhulled Bermuda Seed with 82% pure live
seed having a germination of 85%, Kentucky 31 tail fescue with 88% pure live seed having a
germination of 85%, and Carpet Grass Seed with 80% pure live seed having a germination of 85%.
For spring planting, no change shall be made in composition except that the seed will be hulled.
FERTILIZER: Fertilizer shall be 8-8-8 grade, uniform in'composition, free flowing and
suitable for application with approved equipment, delivered to the site in bags or other convenient
containers each fully labeled, conforming to the application State fertilizer laws, and bearing the name
and warranty of the producer.
Lime shall be ground limestone containing not less than 85% of total carbonates and shall be
ground to such fineness that at least 50% will pass through a 100 mesh sieve and at least 90% will
pass through a 20 mesh sieve.

Equipment necessary for the proper preparation of the ground surface and for handling all
required materials shall be on hand, in good condition.
Clearing: Prior to grading and tillage operations, the ground surface shall be cleared of all
heavy vegetation, stumps, stones, roots, cable wire, grade stakes, and any other material which might
hinder proper grading, tillage or subsequent maintenance operations.
Grading: Grades on the areas to be seeded shall be maintained in a true and even condition,
preventing the formation of depressions where water will stand.
Tillage: After the areas required to be seeded have been brought to the grades shown on the
drawings, the areas shall be thoroughly tilled to a depth of at least 6 inches by plowing, discing,
harrowing or other approved operations until the condition of the soil is acceptable.
Application of Fertilizer: Fertilizer shall be distributed uniformly at a rate of 4 pounds per
100 square feet on areas indicated to be seeded and shall be incorporated into the soil to a depth of
at least 3 inches by discing, harrowing or other acceptable methods. The incorporation of fertilizer
may be a part of the tillage operation specified above.
Application of lime: Immediately following and simultaneously with the incorporation of the
fertilizer, lime shall be distributed uniformly at a rate of 8 pounds per 100 square feet and shall be
incorporated into the soil to a depth of at least 2 inches by discing, harrowing, or other acceptable
methods. The incorporation of the lime with the fertilizer may form a part of the tillage operations
previously specified.
Leveling. Any undulation or irregularities in the surface resulting from tillage, fertilizing,
liming or other operations shall be leveled out before seeding operations are begun.
Seeding: Seeding shall be in accordance with the seeding requirements shown on the plans.
No seeding shall be done during windy weather or when the ground is wet or otherwise non -tillable.
The grass seed shall then be covered, using a flexible toothed weeder or other suitable equipment,
by stirring the ground no deeper than 1/4 inch.
Compaction: Immediately after the seed has been planted, the planted areas shall be leveled
and rolled with a culti-packer, roller, or other approved equipment weighing 60 to 90 pounds per
linear foot of roller.

Watering: Immediately following seeding, when necessary to maintain growth of grass and
in any case when planting is permitted in dry weather, planted areas shall be watered. Each watering
shall be in sufficient quantities to obviate rapid drying out and at a rate of which will not cause
%T11431TON11
Protection: The seeded areas shall be protected against traffic or other use by erecting
barricades immediately after seeding is completed and by placing warning signs on the various areas.