20050675 Ver 1_Stormwater Info_20070328

Blackburn Consulting Engineering
234 East Main Street
Clayton, NC 27520
Phone: [phone]
Fax: [phone]
COVER SHEET
To: North Carolina Department of Natural Resources
Division of Water Quality
Attention: Annette Lucas
Date: March 28, 2007
From: Sean P. Hein M: 669-9487
Subject: Moss Creek Phase 3 and 4
Message:
Enclosed are two sets of construction plans and calculations for your review of
the wet detention pond design for Moss Creek Business Park Phase 3 and 4. DWQ
Project No: OS-0675.
Enclosures:
1. Two sets of construction plans
2. Two sets of calculations
e ~~~~ ~~~
MAR ,~
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4~~~V15,'G?j~E'4T~~~ ~Ft

STORM DRAINAGE SYSTEM AND WET DETENSION POND
CALCULATIONS AND DATA FORMS
FOR
MOSS CREEK PHASE 3 AND 4 SUBDIVISION
CLAYTON, NORTH CAROLINA
March 27, 2007
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Blackburn Consulting Engineering
234 E. Main Street
Clayton, NC 27520
Ph. [phone] Fax [phone]
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Version 4.2 T 2/221200 01:39 PM COMPUTED BY:
PROJECT NO.:
-ROM STATI0NIREACH: PTO STA
HYDRAULIC RESULTS
Discharge
cfs Peak Flow
Period hrs Velocity [fps) Area (sq.ft) Hydraulic
Radius ft Normal
De th ft
d4.0 1.0 4.92 8.94 0.78 1.18
Unreinforced Vegetation
S = 0.0240
LIhIER RESULTS
Bottom
3.0 Width = 4.00 ft 3.0
Not to Scale

Reach Matting Type
Stability Analysis Vegetation Characteristics
Permissible
Calculated
Safety Factor
Remarks
Staple Pattern Phase Class Type Density Shear Stress
[P$f1 Shear Stress
(Psf1
Skraight Unreinforced Vegetation ~ D Mix >=95 0 3.33 1.J7 1.88 STABLE
Soil Sandy Loam 0.035 0.028 1.27 STABLE

~ ~ I u l'1r11J L11. 1'iC ~ V L I .7
Discharge
cfs Peak Flow
Period hrs Velocity (fps) Area (sq.ft) Hydraulic
Radius ft Normal
De th ft
44.0 1.0 8.02 5.49 0.59 0.84
LINER RESULTS
3.0
~~
3.0
Not to Scale

Reach Matting Type
Stability Analysis Vegetation Characteristics
Permissible
Calculated
Safety Factor
Remarks
Staple Pattern Phase Class Type Density Shear Stress
(psf) Shear Stress
[psf)
Straight C125 Unvegetated 2.25 1.26 1.79 STABLE
Staple D ~
Boktom
Width = 4.00 ft

DWQ Project No. ~S "®~ ~ S
DIVISION OF WATER QUALITY -LEVEL SPREADER WORKSHEET (112007)
I. PROJECT INFORMATION (please complete the following
Project Name : JVl G ~ ~~
Contact Person: ,~~,4n/ ~ NEih/
Level Spreader ID: /4~ 1~,~N,G?
Level Spreader Length ~~ ~ _ ft,
Drainage Area ~- _ ac.
Impervious Area Y, 7 ac.
Forebay Area .. ~pr/~ cu ft.
Maximum Filter Strip/Buffer Slope %
grass
Phone Number: (C4'Ks1 SS 3 _
(perpendicular to flow)
(on-site and off-site drainage to the level spreader)
(on-site and off-site drainage to the level spreader)
(0.2% of the contributing impervious surface area)
(6% for forested, leaf littler cover, 8% for thick ground cover
Max, Discharge from 1"IHr Storm ~,. r cfs
Max. Discharge to Level Spreader ®.~ cfs . M1~K ~ fZOM ~on~i~ r,,SG ~q~C;E ~'hi ~z'~c/t~w~ F'rt~
Filter Strip/ Zone 2 Buffer Vegetation Tiff/C/C -- (thick ground cover or grass; canopied forest with eaf litter
5~''~ f-o~~ ~~v/JS groundcover)
Pre-treatment or Bypass Method Used 1/!0~ !' {~a/y/~
%D ~~vE~ Sr,,~E,aDE,~ ~' ~ C~ ~ ~47Er' S~r~4~-G
II. REQUIRED ITEMS CHECKLIST
Initial in the space provided to indicate the following design requirements have been met and supporting documentation is attached. If a
requirement has not been met, attach an explanation of why. At a minimum, a complete stormwater management plan submittal includes
a worksheet for each BMP, design calculations, plans and specifications showing all BMPs and outlet structure details, a detailed
drainage plan and a fully executed operation and maintenance agreement. An incomplete submittal package will result in a request for
additional information and will substantially delay final review and approval of the project.
Applicants Initials
_S'~l~ Project Site was visited prior to designing level spreader.
Date of the Site visit. PLEASE ATTACH TIME-DATED DIGITAL PHOTO OF EXISTING BUFFER CONDITIONS.
SiQlf Level spreader is at least 13 ft. per cfs for thick ground cover or grass or 65 ft per cfs in canopied forest with leaf
litter for 50-foot buffer; 50 ft per cfs for 100-foot buffer, or 40 ft. per cfs for 150-foot buffer.
_ .S f't` Pre-Formed Scour Holes are on flat slopes only,
S No structures are located in protected buffers (must meet no practical alternatives criteria).
Design Alternative (if any) and Bypass method used:
S~'~~ Bypass conveyance method is specified and plan details and calculations are provided.
.'~ Alternative design option is specified and plan details and calculations are provided.
-~~ ~ Discharge to level spreader and subsequent filter strip is hydraulically and spatially separate from the bypass
discharge.
~~ ~ No structures are located in protected buffers.
~- Plan details for the bypass and outlets are provided.
~~~ The operation and maintenance agreement includes annual erosion and vegetation repair.
~~ The operation and maintenance agreement signed and notarized by the responsible party is provided.

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Moss Creek 3 & 4
Stage Area Storage Table
Elev Area Storage
315.0 7429 16212
316.0 9451 24652
317.0 11302 35029
318.0 12541 46950
319.0 13852 60147
320.0 15217 74681
Stage Discharge Table
Elev 4" Pipe Riser Barrel Spillway Total
315.3 0.00 0.00 0.00 0.00 0.00
315.4 0.02 0.00 0.00 0.00 0.02
315.5 0.07 0.00 0.00 0.00 0.07
315.6 0.14 0.00 0.00 0.00 0.14
315.7 0.17 0.00 0.00 0.00 0.17
315.8 0.20 0.00 0.00 0.00 0.20
315.9 0.23 0.00 0.00 0.00 0.23
316.0 0.25 0.00 0.00 0.00 0.25
316.1 0.28 0.00 0.00 0.00 0.28
316.2 0.30 0.00 0.00 0.00 0.30
316.3 0.32 0.00 0.00 0.00 0.32
316.4 0.34 0.00 0.00 0.00 0.34
316.5 0.36 0.00 0.00 0.00 0.36
316.6 0.37 0.00 0.00 0.00 0.37
316.7 0.39 0.00 0.00 0.00 0.39
316.8 0.40 0.00 0.00 0.00 0.40
316.9 0.42 0.00 0.00 0.00 0.42
317.0 0.43 0.00 0.00 0.00 0.43
317.1 0.45 0.00 0.00 0.00 0.45
317.2 0.46 0.38 15.00 0.00 0.84
317.3 0.47 1.07 17.00 0.00 1.55
317.4 0.49 1.97 18.50 0.00 2.46
317.5 0.50 3.04 20.00 0.00 3.53
317.6 0.51 4.24 21.50 0.00 4.75
317.7 0.52 6.15 23.00 0.00 6.67
317.8 0.53 8.64 24.50 0.00 9.17
317.9 0.55 11.54 26.00 0.00 12.09
318.0 0.56 14.80 27.00 0.00 15.36
318.1 0.57 18.36 28.00 0.00 18.93
318.2 0.58 22.21 29.00 0.00 22.79
318.3 0.59 26.32 30.00 0.00 26.91
318.4 0.60 30.67 31.00 0.00 31.27
318.5 0.61 35.25 32.00 0.00 32.61
318.6 0.62 40.05 33.00 0.00 33.62
318.7 0.63 45.05 34.50 0.00 35.13
318.8 0.64 50.26 36.00 0.00 36.64
318.9 0.65 55.66 37.50 0.00 38.15
319.0 0.66 61.24 39.00 0.00 39.66
319.1 0.67 67.01 40.00 1.90 42.56

319.2 0.68 72.95 41.00 5.37 47.04
319.3 0.69 79.06 42.00 9.86 52.54
319.4 0.69 85.33 43.00 15.18 58.87
319.5 0.70 91.76 44.00 21.21 65.92
319.6 0.71 98.35 45.00 27.89 73.60
319.7 0.72 105.09 46.00 35.14 81.86
319.8 0.73 111.97 47.00 42.93 90.66
319.9 0.74 119.01 48.00 51.23 99.97
320.0 0.75 126.19 49.00 60.00 109.75
320.1 0.75 133.51 50.00 69.22 119.97
320.2 0.76 140.96 50.50 78.87 130.13
320.3 0.77 148.55 51.00 88.93 140.70
320.4 0.78 156.27 51.50 99.39 151.67
320.5 0.79 164.12 52.00 110.23 163.01
320.6 0.79 172.11 52.50 121.43 174.72
320.7 0.80 180.21 53.00 132.99 186.79
320.8 0.81 188.44 53.50 144.90 199.21
320.9 0.82 196.80 54.00 157.14 211.95
321.0 0.82 205.27 54.50 169.71 225.03
Moss Creek 3 & 4
Storm Routing
2-year Storm
Time Inflow Storage Stage Outflow
0 0.00 18541 315.30 0
1 0.51 18541 315.30 0.0
2 2.02 18571 315.30 0.0
3 4.45 18693 315.31 0.0
4 7.68 18960 315.34 0.0
5 11.55 19420 315.40 0.0
6 15.86 20112 315.48 0.1
7 20.40 21060 315.59 0.1
8 24.94 22276 315.74 0.2
9 29.25 23761 315.90 0.2
10 33.12 25502 316.09 0.3
11 36.35 27473 316.29 0.3
12 38.78 29635 316.50 0.4
13 40.29 31940 316.72 0.4
14 40.80 34334 316.94 0.4
15 40.29 36757 317.15 0.6
16 38.78 39137 317.36 2.1
17 36.35 41339 317.54 4.0
18 33.29 43279 317.70 6.8
19 30.33 44870 317.83 10.1
20 27.64 46085 317.93 13.1
21 25.19 46960 318.00 15.4
22 22.96 47549 318.05 17.0
23 20.92 47904 318.08 18.0
24 19.07 48077 318.09 18.6
25 17.38:.. 48108 3.18.09 18.6
26 15.84 48032 318.09 18.4

27 14.43 47877 318.07 18.0
28 13.15 47665 318.06 17.4
29 11.99 47412 318.04 16.6
30 10.92 47133 318.01 15.9
31 9.95 46837 317.99 15.0
32 9.07 46531 317.97 14.2
33 8.27 46222 317.94 13.4
34 7.53 45913 317.92 12.6
35 6.87 45608 317.89 11.9
36 6.26 45309 317.87 11.1
37 5.70 45017 317.84 10.4
38 5.20 44733 317.82 9.8
39 4.74 44458 317.80 9.2
40 4.32 44192 317.78 8.6
41 3.93 43936 317.76 8.0
42 3.58 43689 317.74 7.5
43 3.27 43451 317.72 7.1
44 2.98 43223 317.70 6.7
45 2.71 43002 317.68 6.3
46 2.47 42788 317.66 5.9
47 2.25 42582 317.65 5.6
48 2.05 42383 317.63 5.3
49 1.87 42190 317.61 5.0
50 1.71 42002 317.60 4.7
51 1.55 41820 317.58 4.5
52 1.42 41642 317.57 4.3
53 1.29 41467 317.56 4.2
54 1.18 41295 317.54 4.0
55 1.07 41126 317.53 3.8
56 0.98 40960 317.51 3.7
57 0.89 40798 317.50 3.5
58 0.81 40640 317.49 3.4
59 0.74 40485 317.47 3.2
60 0.67 40335 317.46 3.1

WET DETENTION BASIN OPERATION AND MAINTENANCE AGREEMENT
The wet detention basin system is defined as the wet detention pond, pretreatment including forebays and
vegetated filter.
Maintenance activities shall be performed as follows:
After every significant runoff producing rainfall event and at least monthly:
a. Inspect the wet detention basin pond 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.
3. 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 pond 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 4.8 feet in the main pond, the sediment shall be removed.
When the permanent pool depth reads 4.0 feet in the forebay [and micro-pool], the sediment shall be
removed.
BASIN DIAGRAM
(fill in the blanks)
Permanent Pool Elevation 315.3 ft
Sediment moval EI. 311.3~t 75%
----------------- - --Sediment Removal Elevation 310_5 ft- _ 75%
- - - - - - - -------
Bottom E vation 310.0 5% A-. ~
FOREBAY 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.
Page 1 of 2

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.
7. All components of the wet detention basin system shall be maintained in good working order.
8. Level spreaders or other structures that provide diffuse flow shall be maintained every six months. All
accumulated sediment and debris shall be removed from the structure, and a level elevation shall be
maintained across the entire flow spreading structure. Any down gradient erosion must be repaired and/or
replanted as necessary.
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.
r
Print name: riL~i LZ1/~/1~ ~` ~ ~ /`~~iq L
Title: (~ W ~-/~f~
Address: ~ %`l/GIG L ~Q [~ ~,/q `/ ~ G-L/l ~' TDn/ ly ~ ~ 7 5 ~~
Phone
Signat
Date: .~ ~ ~~' ~
Note: The legally responsible party should not be a homeowners association unless more than 50% of the
lots have been sold and a resident of the subdivision has been named the president.
I, ~r-~~l ~• /`~~%~ , a Notary Public for the State of IYo,~yH l~~~L~tii ,
County of i ~ HK5Z~iS/ , do hereby certify that t~1/,eu r`.d.~•^/~~ C~iN~4 L.~
personally appeared before me this ~ day of ,/~'441~r~ , ZQo"a ,and acknowledge the due
execution of the forgoing wet [wetland] detention basin maintenance requirements. Witness my hand and
official seal,
SEAN P. REIN
NOTARY PUBLIC
JOHNSTON COUNTY, N.C.
My Commission Expires 6-12-2011.
SEAL
My commission expires ~ ' / ~ - ~ ~1/
Page 2 of 2

LEVEL SPREADER OPERATION AND MAINTENANCE AGREEMENT
The level spreader is defined as an elongated, level threshold, designed to diffuse stormwater runoff.
Maintenance activities shall be performed as follows:
1. After construction and until vegetation has been established, level spreader(s) shall be inspected after
every rainfall. Thereafter, level spreader(s) shall be inspected at least every month and more
frequently during the fall season and after heavy rainfall events:
a. Accumulated sediment, leaves, and trash shall be removed, and repairs made if required.
b. Inspect level spreader(s) for evidence of scour, undercutting, settlement of the structure, and
concentrated flows downhill from the level spreader(s).
c. A level elevation shall be maintained across the entire flow-spreading structure at all times.
Repair or replace the level spreader if it is damaged.
d. Mow vegetative cover to a height of six (6) inches and prune plants if they cover over half of the
level spreader surface.
e. Repair eroded areas and replace/replant dead or damaged vegetation.
2. The contractor should avoid the placement of any material on and prevent construction traffic across
the structure. If the measure is damaged by construction traffic, it shall be repaired immediately.
3. Inspect and repair the collection system (e.g., catch basins, pipes, swales, riprap) four (4) times a year
to maintain proper functioning.
I acknowledge and agree by my signature below that I am responsible for the performance of the 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.
Print name: ~`'L~lAn~t ,~-~ ~ ~n/~'AL
Title: ~~/~~ /~
Address: ~J /~lG,~ L .SUS ~,/A~ L~~Yi ~~ ~1` ~ ~-~S~n
Phon
Signature:
_ ~ _ ,1
f
Date: ,~ 2 ~ O °7
Note: The legally responsible party should not be a homeowners association unless more than 50% of the
lots have been sold and a resident of the subdivision has been named the president.
I, ~r~~~ ~/f//~/ , a Notary Public for the State of iy~~r{;r ~,a ~.i,~~~¢ ,
County of ~,~,c/Sr d/y , do h~~eby certify that ~0[~_ jLQM ~~ ~ ~/V~A L.-~
personally appeared before me this ~_ day of ~~ , ,~ 7 ,and acknowledge the due
execution of the forgoing wet [wetland] detention basin maintenance requirements. Witness my hand and
official seal,
SEAN P. HEIN
NOTARY PUBLIC
JOHNSTON COUNTY, N.C.
My Commission Expires6-12-2011.
SEAL
/i^~°C~
My commission expires ~ ~Z -Z~/~
Page 1 of 1

STORM DRAINAGE SYSTEM AND WET DETENSION POND
CALCULATIONS AND DATA FORMS
FOR
MOSS CREEK PHASE 3 AND 4 SUBDIVISION
CLAYTON, NORTH CAROLINA
March 27, 2007
s,F~ o~a+~ en® tpc r rrys
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9486 ~ ~'
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49 : ~ ~~ r ~
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Blackburn Consulting Engineering
234 E. Main Street
Clayton, NC 27520
Ph. [phone] Fax [phone]
3 ~z 7 ~~ .~

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4.2
FROM 5TATIONIREACH: jT0 5TAT10
HYDRAULIC RESULTS
Discharge
cfs Peak Flow
Period hrs Velocity [fpsj Area [sq.ftJ Hydraulic
Radius ft Normal
De th ft
44.0 1.0 4.92 8.94 0.78 1.18
LINER RESULTS
OJECT
Unreinforced Vegetation (n=0.
S = 0.0240
1~ ~1
Bottom
3.0 Width = 4.00 ft 3.0
Not to Scale

Reach Matting Type
5tabilityAnalysis Vegetation Characteristics
Permissible
Calculated
Safety Factor
Remarks
Staple Pattern Phase Class Type Density Shear Stress
(psfJ Shear Stress
(psfJ
Straight Unreinforced Vegetation ~ D Mix >=95% 3.33 1.77 1.88 STABLE
Soil Sandy Loam 0.035 0.028 1.27 STABLE

4.2
'ROM STATIONIREACH: TO STATION
HYDRAULIC RESULTS
Discharge
cfs Peak Flow
Period hrs Velocity (fps) Area (sq.ft) Hydraulic
Radius ft Normal
De th ft
44.0 1.0 8.02 5.49 0.59 0.84
LINER RESULTS
34 PM(COMPUTED BY:
C125 (n=0.020)
S = 0.0240 /
~~
1~ ~~
Bottom
3.0 Width = 4.00 ft 3.0
Not to Scale

Reach Matting Type
5tabilityAnalysis Vegetation Characteristics
Permissible
Calculated
Safety Factor
Remark

Staple Pattern
Phase
Class
Type
Density
Shear Stress
(psf)
Shear Stress
(psf) s
Straight C125 Unvegetated 2.25 1.26 1.79 STABLE
Staple D

DWQ Project No. ~S '©6 ~ s
DIVISION OF WATER QUALITY • LEVEL SPREADER WORKSHEET (112007)
I. PROJECT INFORMATION
Project Name : ~ f~
Contact Person:~~
Level Spreader ID: ~~_
the
Phone Number: (q/ql SS 3
Level Spreader Length
Drainage Area
Impervious Area
Forebay Area ~- j~p~~
Maximum Filter Strip/Buffer Slope
grass
~~ ft.
ac.
.7 ac.
_._cu ft.
(perpendicular to flow)
(on-site and off-site drainage to the level spreader)
(on-site and off-site drainage to the level spreader)
(0.2% of the contributing impervious surface area)
(6% for forested, leaf littler cover, 8% for thick ground cover
Max. Discharge from 1 "/Hr Storm "7» ~ cfs
Max. Discharge to Level Spreader ~.~ cfs . Mac ~~~~~ r'aN~~ r, fSLHA1~~;E /~! ~x'~~wr,r P~t~
Filter Strip/ Zone 2 Buffer Vegetation T~fl Ck --- (thick ground cover or grass; canopied forest with eat litter
Sr'7~t ~-0~2 L+'~vlJS groundcover)
Pre-treatment or Bypass Method Used ~JO~ ~ F~l~//~
(D L~1lGG Sf~,~'E.4DEk~ '~ ~.l F i *47,~~ s~/,~L~
II. REQUIRED ITEMS CHECKLIST
Initial in the space provided to indicate the following design requirements have been met and supporting documentation is attached. If a
requirement has not been met, attach an explanation of why. At a minimum, a complete stormwater management plan submittal includes
a worksheet for each BMP, design calculations, plans and specifications showing all BMPs and outlet structure details, a detailed
drainage plan and a fully executed operation and maintenance agreement. An incomplete submittal package will result in a request for
additional information and will substantially delay final review and approval of the project.
Applicants Initials
S~H Project Site was visited prior to designing level spreader.
Date of the Site visit. PLEASE ATTACH TIME-DATED DIGITAL PHOTO OF EXISTING BUFFER CONDITIONS.
SP/f Level spreader is at least 13 ft. per cfs for thick ground cover or grass or 65 ft per cfs in canopied forest with leaf
litter for 50-foot buffer; 50 ft per cfs for 100-foot buffer, or 40 ft. per cfs for 150-foot buffer.
.~ ~ H Pre-Formed Scour Holes are on flat slopes only.
~S No structures are located in protected buffers (must meet no practical alternatives criteria).
Design Alternative (if any) and Bypass method used:
~''~ ~ Bypass conveyance method is specified and plan details and calculations are provided.
_~ Alternative design option is specified and plan details and calculations are provided.
-~~~ Discharge to level spreader and subsequent filter strip is hydraulically and spatially separate from the bypass
discharge.
~~ ~ No structures are located in protected buffers.
f- Plan details for the bypass and outlets are provided.
The operation and maintenance agreement includes annual erosion and vegetation repair.
_ ~~-The operation and maintenance agreement signed and notarized by the responsible party is provided.

Project No. DWQ_ O S -• d 6 ~~ (to be provided by DWQ)
DIVISION OF WATER QUALITY - 401 WET DETENTION BASIN WORKSHEET
DWO Stormwater Management Plan Review
A complete stormwater management plan submittal includes a wet detention basin worksheet for each basin,
design calculations, plans and specifications showing all basin and outlet structure details, and a fully executed
operation and maintenance agreement. An incomplete submittal package will result in a request for additional
information and will substantially delay final review and approval of the project.
I. PROJECT INFORMATION (please complete the following information):
Project Name : /~ D ~ ~_~. F~= ~ /~H,4;~E ~ ~ 1 f
Contact Person: ~F.~g~L f1 ~~~~~ Phone Number: (`1'~j) 5S~ - ~~or~
For projects with multiple basins, specify which basin this worksheet applies to: D/Y~
Basin Bottom Elevation ~O ~j. ~ ft. (average elevation of the floor of the basin)
Permanent Pool Elevation '-~l $.3 ft. (elevation of the orifice invert out)
Temporary Pool Elevation 3 t 7, ! ft. (elevation of the outlet structure invert in)

Permanent Pool Surface Area 8 b 35 sq. ft. (water surface area at permanent pool elevation)
Drainage Area ll. g ac. (on-site and off-site drainage to the basin)
Impervious Area ~.? ac. (on-site and off-site drainage to the basin)

Permanent Pool Volume /~~ 3 / 9 cu. ft. (combined volume of main basin and forebay)
Temporary Pool Volume 1'7 , (7 9 cu. ft. (volume detained on top of the permanent pool)
Forebay Volume ~5 ~ / cu. ft.

SA/DA used C9• C7 / S6 (surface area to drainage area ratio)
Diameter of Orifice ~/ in. (draw down orifice diameter)
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, November 1995) and Administrative Code
Section: 15 A NCAC ZH .1008. Initial in the space provided to indicate the following design requirements have
been met and supporting documentation is attached. If a requirement has not been met, attach an explanation of
why.
Applicants Initials
SPAY The temporary pool controls runoff from the 1 inch storm event.
-s~°f'' The basin length to width ratio is greater than 3:1.
S~/'~ The basin side slopes are no steeper than 3:1.
SPH A submerged and vegetated perimeter shelf at less than 6:1 is provided.
591f Vegetation to the permanent pool elevation is specified.
An emergency drain is provided to drain the basin. - j3o ~dM pf PoNp is (pVEjZ
s~° The permanent pool depth is between 3 and 6 feet (required minimum of 3 feet).
~ The temporary pool draws down in 2 to 5 days.
S~~f The forebay volume is approximately equal to 20% of the total basin volume.
SOH Sediment storage is provided in the permanent pool.
S PH Access is provided for maintenance.
S N A minimum 30-foot vegetative filter is provided at the outlet.
A site specific operation and maintenance (O&M) plan is provided.
_ A vegetation management/mowing schedule is provided in the O&M plan.
Semi-annual inspections are specified in the O&M plan.
V A debris check is specified in the O&M plan to be performed after every storm event.
~nl~ A specific sediment clean-out benchmark is listed (elevation or depth) in O&M plan.
`~,!' f7 A responsible party is designated in the O&M plan.
FORM SWG]00 09/97 Page 1 of l
~'~ sr~~,

Impervious Surface Area Calculations for Moss Creek Phases 3 and 4
Total area in site =
Roads
Curb and Pavement
Sidewalk
Alley
Total Roads
Lots
House and porch
Driveway
Deck
Sidewalk
Total Lot
Total Impervious Surface Area:
Roads
Lots (81 '` 2380 sf)
Total Impervious
Percent Impervious
18.0870 acres 787,868 sf
67,728 sf
11, 057 sf
40018 sf
118,803 sf
1210 sf
940 sf
120 sf
110 sf
2380 sf
118,803 sf
192,780 sf
311, 583 sf
39.6%

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Moss Creek 3 & 4
Stage Area Storage Table
Elev
315.3
315.4
315.5
315.6
315.7
315.8
315.9
316.0
316.1
316.2
316.3
316.4
316.5
316.6
316.7
316.8
316.9
317.0
317.1
317.2
317.3
317.4
317.5
317.6
317.7
317.8
317.9
318.0
318.1
318.2
318.3
318.4
318.5
318.6
318.7
318.8
318.9
319.0
319.1
Elev Area Storage
315.0 7429 16212
316.0 9451 24652
317.0 11302 35029
318.0 12541 46950
319.0 13852 60147
320.0 15217 74681
Stage Discharge Table
4" Pipe Riser Barrel S ila Iwav Total
0.00 0.00 0.00 0.00 0.00
0.02 0.00 0.00 0.00 0.02
0.07 0.00 0.00 0.00 0.07
0.14 0.00 0.00 0.00 0.14
0.17 0.00 0.00 0.00 0.17
0.20 0.00 0.00 0.00 0.20
0.23 0.00 0.00 0.00 0.23
0.25 0.00 0.00 0.00 0.25
0.28 0.00 0.00 0.00 0.28
0.30 0.00 0.00 0.00 0.30
0.32 0.00 0.00 0.00 0.32
0.34 0.00 0.00 0.00 0.34
0.36 0.00 0.00 0.00 0.36
0.37 0.00 0.00 0.00 0.37
0.39 0.00 0.00 0.00 0.39
0.40 0.00 0.00 0.00 0.40
0.42 0.00 0.00 0.00 0.42
0.43 0.00 0.00 0.00 0.43
0.45 0.00 0.00 0.00 0.45
0.46 0.38 15.00 0.00 0.84
0.47 1.07 17.00 0.00 1.55
0.49 1.97 18.50 0.00 2.46
0.50 3.04 20.00 0.00 3.53
0.51 4.24 21.50 0.00 4.75
0.52 6.15 23.00 0.00 6.67
0.53 8.64 24.50 0.00 9.17
0.55 11.54 26.00 0.00 12.09
0.56 14.80 27.00 0.00 15.36
0.57 18.36 28.00 0.00 18.93
0.58 22.21 29.00 0.00 22.79
0.59 26.32 30.00 0.00 26.91
0.60 30.67 31.00 0.00 31.27
0.61 35.25 32.00 0.00 32.61
0.62 40.05 33.00 0.00 33.62
0.63 45.05 34.50 0.00 35.13
0.64 50.26 36.00 0.00 36.64
0.65 55.66 37.50 0.00 38.15
0.66 61.24 39.00 0.00 39.66
0.67 67.01 40.00 1.90 42.56

319.2 0.68 72.95 41.00 5.37 47.04
319.3 0.69 79.06 42.00 9.86 52.54
319.4 0.69 85.33 43.00 15.18 58.87
319.5 0.70 91.76 44.00 21.21 65.92
319.6 0.71 98.35 45.00 27.89 73.60
319.7 0.72 105.09 46.00 35.14 81.86
319.8 0.73 111.97 47.00 42.93 90.66
319.9 0.74 119.01 48.00 51.23 99.97
320.0 0.75 126.19 49.00 60.00 109.75
320.1 0.75 133.51 50.00 69.22 119.97
320.2 0.76 140.96 50.50 78.87 130.13
320.3 0.77 148.55 51.00 88.93 140.70
320.4 0.78 156.27 51.50 99.39 151.67
320.5 0.79 164.12 52.00 110.23 163.01
320.6 0.79 172.11 52.50 121.43 174.72
320.7 0.80 180.21 53.00 132.99 186.79
320.8 0.81 188.44 53.50 144.90 199.21
320.9 0.82 196.80 54.00 157.14 211.95
321.0 0.82 205.27 54.50 169.71 225.03
Moss Creek 3 & 4
Storm Routing
2-year Storm
Time Inflow Storage Stage Outflow
0 0.00 18541 315.30 0
1 0.51 18541 315.30 0.0
2 2.02 18571 315.30 0.0
3 4.45 18693 315.31 0.0
4 7.68 18960 315.34 0.0
5 11.55 19420 315.40 0.0
6 15.86 20112 315.48 0.1
7 20.40 21060 315.59 0.1
8 24.94 22276 315.74 0.2
9 29.25 23761 315.90 0.2
10 33.12 25502 316.09 0.3
11 36.35 27473 316.29 0.3
12 38.78 29635 316.50 0.4
13 40.29 31940 316.72 0.4
14 40.80 34334 316.94 0.4
15 40.29 36757 317.15 0.6
16 38.78 39137 317.36 2.1
17 36.35 41339 317.54 4.0
18 33.29 43279 317.70 6.8
19 30.33 44870 317.83 10.1
20 27.64 46085 317.93 13.1
21 25.19 46960 318.00 15.4
22 22.96 47549 318.05 17.0
23 20.92 47904 318.08 18.0
24 19.07 48077 318.09 18.6
25 17.38 48108 . 318A9 1$.6`:
26 15.84 48032 318.09 18.4

27 14.43 47877 318.07 18.0
28 13.15 47665 318.06 17.4
29 11.99 47412 318.04 16.6
30 10.92 47133 318.01 15.9
31 9.95 46837 317.99 15.0
32 9.07 46531 317.97 14.2
33 8.27 46222 317.94 13.4
34 7.53 45913 317.92 12.6
35 6.87 45608 317.89 11.9
36 6.26 45309 317.87 11.1
37 5.70 45017 317.84 10.4
38 5.20 44733 317.82 9.8
39 4.74 44458 317.80 9.2
40 4.32 44192 317.78 8.6
41 3.93 43936 317.76 8.0
42 3.58 43689 317.74 7.5
43 3.27 43451 317.72 7.1
44 2.98 43223 317.70 6.7
45 2.71 43002 317.68 6.3
46 2.47 42788 317.66 5.9
47 2.25 42582 317.65 5.6
48 2.05 42383 317.63 5.3
49 1.87 42190 317.61 5.0
50 1.71 42002 317.60 4.7
51 1.55 41820 317.58 4.5
52 1.42 41642 317.57 4.3
53 1.29 41467 317.56 4.2
54 1.18 41295 317.54 4.0
55 1.07 41126 317.53 3.8
56 0.98 40960 317.51 3.7
57 0.89 40798 317.50 3.5
58 0.81 40640 317.49 3.4
59 0.74 40485 317.47 3.2
60 0.67 40335 317.46 3.1

WET DETENTION BASIN OPERATION AND MAINTENANCE AGREEMENT
The wet detention basin system is defined as the wet detention pond, pretreatment including forebays and
vegetated filter.
Maintenance activities shall be performed as follows:
After every significant runoff producing rainfall event and at least monthly:
a. Inspect the wet detention basin pond 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.
3. 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 pond 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 4.8 feet in the main pond, the sediment shall be removed.
When the permanent pool depth reads 4.0 feet in the forebay [and micro-pool], the sediment shall be
removed.
BASIN DIAGRAM
(fill in the blanks)
Permanent Pool Elevation 315.3 ft
Sediment moval EI. 311.31ft 75%
----------------- -- Sediment Removal Elevation 310.5 ft- 75%
- - - - - - -- -------
Bottom E vation 310.0 5% ~-
FOREBAY 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.
Page 1 of 2

6. If the basin must be drained for an emergency or to pertorm maintenance, the flushing of sediment
through the emergency drain shall be minimized to the maximum extent practical.
7. All components of the wet detention basin system shall be maintained in good working order.
8. Level spreaders or other structures that provide diffuse flow shall be maintained every six months. All
accumulated sediment and debris shall be removed from the structure, and a level elevation shall be
maintained across the entire flow spreading structure. Any down gradient erosion must be repaired and/or
replanted as necessary.
I acknowledge and agree by my signature below that I am responsible for the pertormance 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.
Print name: ~il~iL~1~M ~ ~ ~ /`~~AL
Title: d W ~/~/~
Address: ~ f`l/GlC L ~4 ~~ ~,/~4 `l GG~4 ~' ~"nN !Y ~ ~ 7 5 ~v
Phone:
Signat~
Date: ~ ~ ~~' ~
Note: The legally responsible party should not be a homeowners association unless more than 50% of the
lots have been sold and a resident of the subdivision has been named the president.
1, -SC~I~I ~• C~~C~ , a Notary Public for the State of ~yo,~yf/ ~~~Z~L~tii ,
County of i ~HA%SZ~~/ , do hereby certify that 1/d~ru(A~ /~- C~N~.4L
personally appeared before me this ~ day of /Y1~4~~ _, and acknowledge the due
execution of the forgoing wet [wetland] detention basin maintenance requirements. Witness my hand and
official seal,
SEAN P. REIN
NOTARY PUBLIC
JOHNSTON COUNTY, N.C.
My Commission Expires 6-12-2011.
My commission expires ~ ' ~ ~ - ~ ~C/
Page 2 of 2

LEVEL SPREADER OPERATION AND MAINTENANCE AGREEMENT
The level spreader is defined as an elongated, level threshold, designed to diffuse stormwater runoff.
Maintenance activities shall be performed as follows:
1. After construction and until vegetation has been established, level spreader(s) shall be inspected after
every rainfall. Thereafter, level spreader(s) shall be inspected at least every month and more
frequently during the fall season and after heavy rainfall events:
a. Accumulated sediment, leaves, and trash shall be removed, and repairs made if required.
b. Inspect level spreader(s) for evidence of scour, undercutting, settlement of the structure, and
concentrated flows downhill from the level spreader(s).
c. A level elevation shall be maintained across the entire flow-spreading structure at all times.
Repair or replace the level spreader if it is damaged.
d. Mow vegetative cover to a height of six (6) inches and prune plants if they cover over half of the
level spreader surface.
e. Repair eroded areas and replace/replant dead or damaged vegetation.
2. The contractor should avoid the placement of any material on and prevent construction traffic across
the structure. If the measure is damaged by construction traffic, it shall be repaired immediately.
3. Inspect and repair the collection system (e.g., catch basins, pipes, swales, riprap) four (4) times a year
to maintain proper functioning.
I acknowledge and agree by my signature below that I am responsible for the performance of the 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.
Print name: ~/~'L~IAM ,~~ ~ r~/~,AL
Title: t~l~,/N~ /~
Arirlracc• ~ /~,~//' L i dr iC i id r! ~1 /4~/i hl1,l ~ L ~~~J~~
Note: The legally responsible party should not be a homeowners association unless more than 50% of the
lots have been sold and a resident of the subdivision has been named the president.
I, ~r~g~,~ ~/f//~/ , a Notary Public for the State of ~/~ r{{ ~,a it/r~ ,
County of ~t~~-~<d/V , do h~yeby certify that ~~,~~jLgM Iz_ a ~.N~{
personally appeared before me this ~~ day of ~~~f z~ 7 ,and acknowledge the due
execution of the forgoing wet [wetland] detention basin maintenance requirements. Witness my hand and
official seal,
SEAN P. REIN
NOTARY PUBLIC
JOHNSTON COUNTY, N.C.
My Commission Expires 6-12-2011.
SEAL
~C/
My commission expires ~ ~Z ~Z~//
Page 1 of 1
Date: .~ 2 ~ t~ ~7