20070343 Ver 1_Stormwater Info_20070402

LAND
~~ PLANNING
= ASSOCIATES, INC.
off- 0343
Letter of Transmittal
TO: Ian McMillan NCDWO 401
2321 Crabtree Blvd
Raleigh, NC 27604
Land Planning Associates Inc. is forwarding the following information via:
Hand Mail D UPS Express Mail Fax
We are sending you : D Prints Reproducibles D Other
D 24 x 36 24 x 36 Letter/Memo
30x42 30x42 D 8'hx11
COPIES DATE DRAWING # DESCRIPTION
1 SWM Report (with DWO info tabbed)
1 Civil plans for Ponds

These are Transmitted : D For Approval For Your Information For Review & Approval
As Requested By:
REMARKS: Enclosed is a copy of our stormwater plans that meet DWQ standards. Hart &
Hickman have submitted a PCN for this project under separate cover. Please call or email with any
questions.
Signed:
Date: March 30, 2007
Project # : 6.035
Project: Lowe's E. Greenville
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Pnone.864.242.6072 FaX [phone] aaaress:110 West 1st Avenue. Suite A • Easley SC 29640

0~-03-}3
STORM WATER MANAGEMENT REPORT
LOWE'S OF GREENVILLE, NORTH CAROLINA
GREENVILLE, NORTH CAROLINA
PREPARED FOR:
LOWE'S HOME STORES, INC.
Date: March 5, 2007
PREPARED BY:
LAND PLANNING ASSOCIATES, INC.
110 West 1St Avenue, Suite A
Easley, SC 29640
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Table of Contents
Section
Project Summary
Pre-Developed Conditions
Post-Developed Conditions
Storm Water Management
Dewatering Time Calculations
Storm Drainage Calculations
Sediment and Erosion Control
Total Nitrogen and Total Phosphorus Loading Calculations
NCDENR Worksheets
Figure 1 -Pre Developed Conditions
Figure 2 -Post Developed Conditions
Appendix A - TR-55 Calculations
Pre Developed Conditions
Post Deveioped Conditions
Appendix B - Hydraflow Hydrograph Calculations
Summary Sheet 1-yr Storm
1-yr Storm Hydrograph Sheets
Summary Sheet 2-yr Storm
2-yr Storm Hydrograph Sheets
Summary Sheet 10-yr Storm
10-yr Storm Hydrograph Sheets
Summary Sheet 25-yr Storm
25-yr Storm Hydrograph Sheets
Summary Sheet 100-yr Storm
100-yr Storm Hydrograph Sheets
Pond 1 Detail Information
Pond 2 Detail Information
Page
1
1
2
3
5
5
5
5
5
6
7
A
Al - A3
A4-A12
B
B1
B2- B8
B9
B10-B16
B17
B18-B24
B25
B26 - B32
B33
B34 - B40
B41 - B43
B44 - B46
Appendix C - Forebay /Pond Calculations C1 - CS

Appendix D -First Flush Calculations /Dewatering Time Calculations D
Dewatering Time Calculations D 1 - D2
1" Storm Runoff (First Flush) D3 - D6
Appendix E - Hydraflow Storm Sewer Calculations E
Storm Drain Drainage Area Map El
Storm Sewer Calculation Sheets E2 - E10
Appendix F -Sediment and Erosion Control Calculations F
Sediment Trap and Basin Calculations F1 - F4
Faircloth Skimmer Details and Information FS - F9
Rip-Rap Apron Calculations F10 - F12
Appendix G - Total Nitrogen and Total Phosphorus Loading G
Drainage Area Map G1
BMP Removal Calculations G2 - G3
Pre Developed TN and TP Loading Calculations G4
Post Developed TN and TP Loading Calculations GS - G7
Appendix H - NCDENR Worksheets H
Wet Detention Basin Worksheet -Pond 1 H 1
Wet Detention Basin Worksheet -Pond 2 H2
Level Spreader Worksheet -Pipe Outlet Pond 1 H3
Level Spreader Worksheet -Pipe Outlet Pond 2 H4

Greenville, North Carolina
Storm Water Management and Erosion Control Report
' Project Summary
The proposed project consists of the development a 20.34 acre site located at the
southwest quadrant of Foxhaven Road and NC Highway 33 /East 10~" Street in
' Greenville, NC. The Lowe's store will be 139,410 square feet with a 31,659 square foot
garden center with associated parking, utilities and storm water management. Also
included is the development of a new public road, Oakdowne Way, and 1 outparcel.
'
Pre Developed Conditions
In the pre-developed condition the site consists of a combination of woods and
' grass/brush combination. The runoff from the site is directed to the western property line
where the boundary of the property where existing wetlands and drainage creek flow
from south to north along the property line.
'
In addition to the ro ert there is a small area of offsite runoff north of the site that will
p p Y~

' be directed to the western property line. Therefore, the total area analyzed was found to
Refer to Figure 1 for a delineation of the area
be 21
71 acres
.
.
.
' Of this 21.71 acres, there is a total of 0.1 acres of impervious surface, 4.21 acres of
woods, mainly located along the western border of the property, and 17.4 acres of brush /
grass mix. Using TR-55, the weighted curve number for this property was found to be
51.
The tiiiic of cor~centratioii, based oii a path of 30^v feet of sheet flew at 2.6 io slope, 32.`,
feet of concentrated flow at a slope of 1.2% and 1025 feet of ditch flow at a slope of 3%
for an estimated time of 30 minutes. Refer to Appendix A for a copy of the TR-55
calculations.
' This information was input into the computer program Hydraflow Hydrographs to
generate a hydrograph for each area and storm. A summary of the results is as follows:
'
Table 1
Pre Developed Runoff
Storm Event Runoff (cfs)
' 1-year 1.07 (see p. B 1 }
2-year 2.80 (see p. B9)
' 10-year 18.98 (see p. B 17)
25-year 30.06 (seep. B25)
100-year 41.15 (see p. B33)

A copy of the Hydraflow printouts are included in the Appendix B of this report.
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Post-Developed Conditions
Due to the location of proposed storm water management ponds, there will be three
drainage areas in the post-developed condition. Area 1 will direct runoff to the main
pond located along the western property line at the rear of the store. Area 2 will direct
runoff to the smaller detention pond located along the northern side of the proposed
building. Area 3 is a small area of direct runoff that will continue to flow to the western
property line. Refer to Figure 2 for a delineation of the post-developed drainage areas.
Area 1 consists of 10.9 acres. Of this area, 8.98 acres is considered impervious surface,
2.01 acres is open space for a weighted curve number of 91. The time of concentration
for this area is based on 166 feet of sheet flow with a slope of 2.5%, 200 feet of
concentrated flow with a slope of 0.5%, and 858~linear feet of pipe flow with an
estimated velocity of 3 fps for a time of 8 minutes.
Area 2 is 6.58 acres and consists of 4.21 acres of impervious surface and 2.37 acres of
open space. Using TR-55, the weighted curve number was found to be 85. (This is based
on 85% impervious surface for the outparcel included in this area) The time of
concentration is based on a path of 160 feet of sheet flow at 2.6% slope and 5741inear
feet of pipe flow with an average velocity of 3 fps for a time of 5 minutes.
The direct runoff area, Area 3, consists of 4.13 acres and is located along the northern
side of the property. This area consists of 0.1 acres of impervious surface, 1.92 acres of
woods, 0.59 acres of open space and 1.52 acres of brush/grass for a weighted curve
number of 54. The time of concentration for this area is approximately 16 minutes based
on a path of 169 feet of sheet flow at 1.7% slope, 300 feet of concentrated flow at a slope
of 6% and 901inear feet of pipe flow with an estimated velocity of 3 fps.
Refer to Appendix A for a copy of the TR-55 calculations.
This information was input into the computer program Hydraflow Hydrographs to
generate a hydrograph for each area and storm. A summary of the results is as follows:
Table 2
Post Developed Runoff (cfs)
Storm Event Area 1 Area 2 Area 3
1-year 43.13
2-year 50.96
10-year 83.58
25-year 98.95
100-year 112.72
23.27 0.62 (see p. B1)
28.33 1.40 (see p. B9)
50.0 6.85 (see p. B 17)
60.32 10.15 (see p. B25)
69.58 13.36 (see p. B33)
A copy of the Hydraflow printouts are included in the Appendix B of this report.
2

Storm Water Management
In order to control the post-developed runoff at apre-developed rate, two storm water
detention pond have been proposed for this project. Combining the runoff from both
ponds and the direct runoff from Area 3, the post-developed runoff from the site will be
below the pre-developed rate for the 1-year, 2-year, 10-year, and 25-year storms. The
detention ponds have also been designed to handle the release of the 100-year storm for
the post-developed condition.
L

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Area 1
The pond designed for this area consists of a storm water pond with a forebay area. The
top of the pond is located at elevation 39 and the bottom of the pond is at elevation 31.
The total volume provided at elevation 39.0 is 6.179 acre-feet or 269,157 cubic feet. The
forebay consists of 54,146 cubic feet and ranges in depth from elevation 31 to 35. The
earthen dam between the forebay and the rest of the pond is at elevation 35.0. As
required by NCDENR regulations, the forebay consists of 20% +/-2% of the total pond
volume. This pond has been designed for a forebay volume of 20.8% of the total pond
volume. Refer to Appendix C for the pond calculations on forebay and pond design.
The outlet structure for the pond consists of a 24 inch diameter riser with a top elevation
of 36.75 and two 18 inch diameter barrel pipes located at elevation 31.0. Two barrel
pipes have been provided for this riser in order to discharge the flow to two separate level
spreaders, providing a larger level spreader area. In the riser there is a 2 inch diameter
orifice at elevation 31.0 and two (2) twelve inch (12") diameter orifices at elevation 35.
There is also a 15 foot wide emergency spillway located at elevation 37.0. The top of the
pond is at elevation 39, therefore one foot of freeboard has been provided over the one-
halffoot high spillway. (Refer to Reservoir Report, P. B41 thru B43 in Appendix B)
Based ors tl-iis design, the post-developed runoff ~r Area 1 was routed thra the po~~d
using Hydraflow Hydrographs. The post-developed release from the pond was found to
be:
Table 3
Post-Developed Release from Pond 1 (cfs)
Storm Event Area 1 Elevation (ft)
1-year 0.19 34.37 (see p. B1)
2-year 0.20 34.92 (seep. B9)
10-year 3.41 35.68 (see p. B 17)
25-year 6.21 36.13 (see p. B25)
100-year 8.24 36.62 (see p. B33)
Area 2
' The pond designed for Area 2 also consists of a storm water pond with a forebay area.
The top of the pond is located at elevation 46 and the bottom of the pond is at elevation
39. The total volume in the pond is 3.282 ac-ft or 142,963 cubic feet. The forebay
' consists of 28,595 cubic feet and ranges in depth from elevation 39 to 42. The earthen
dam between the forebay and the rest of the pond is at elevation 42.0. As required by

' 3

NCDENR regulations, the forebay consists of 20% +/-2% of the total pond volume. This
pond has been designed for a forebay volume of 20.8% of the total pond volume. Refer
to Appendix C for the pond calculations on forebay and pond design.
The outlet structure for the pond consists of a 24 inch diameter riser with a top elevation
of 43.5 and a 18 inch diameter barrel pipe located at elevation 39.0 that will discharge to
a level spreader. There is a two-inch diameter orifice at elevation 39.0 and three 6"
diameter orifices at elevation 42.0. There is also a 10-foot wide emergency spillway
located at elevation 44.0. The top of the pond is at elevation 46, therefore one foot of
freeboard has been provided over the one foot high spillway. (Refer to Reservoir Report
page B44 thru B46 in Appendix B)
Based on this design, the post-developed runoff for Area 2 was routed thru the pond
using Hydraflow Hydrographs. The post-developed release from the pond was found to
be:
Table 4
Post-Developed R elease from P ond 2 (cfs)
Storm Event Area 2 Elevation (ft)
1-year 0.17 41.65 (see p. B 1)
2-year 0.27 42.10 (see p. B9)
10-year 2.47 42.90 (see p. B 17)
25-year 3.36 43.49 (see p. B25)
100-year 9.55 43.77 (see p. B33)
Combining the post-release from the Pond 1 and Pond 2 with the direct runoff observed
during the post-developed condition, a total post-developed runoff for the 21.71 acres
was determined. The Hydraflow results are as follows:
Table 5
Overall Post-Developed Runoff
Storm Event Overall Area (cfs)
1-year 0.90
2-year 1.71
10-year 9.14
25-year 17.58
100-year 29.25
' A copy of the Hydraflow printouts are included in the Appendix B of this report.
Shown by the above table, the storm water management ponds proposed for this
' development are capable of controlling and releasing the 1, 2, 10, and 25 storms at below
the pre-developed rate and releasing the 100-year storm.
4

t Dewaterin~ Time
The dewatering time for the temporary pool during a 10-year storm event was calculated
' for both Pond 1 and Pond 2. The temporary pool is the runoff from the 1" storm over the
drainage area. A copy of the calculations for this first flush volume and the dewatering
time calculation is found in Appendix D of this report. The dewatering time for the
' temporary pool from Pond 1 is approximately 4 days and from Pond 2 is 2 days.
Storm Drain Pipe Calculations
The computer program Hydraflow Storm Sewers was used to model the proposed storm
drain pipe systems for this project. The pipes have been sized based on a 10-year design
storm. A copy of the computer results are provided in the Appendix E of this report.
Sediment and Erosion Control
In order to reduce the amount of sediment leaving the site during construction, inlet
protection, silt fence and sediment basins will be used on site. In addition, a stone
construction entrance and temporary and permanent seeding have been specified on the
' plans.
' Calculations for the Sediment Basins have been based on the NC Erosion and Sediment
Control Planning and Design Manual. Volume and surface area requirements are shown
on the plans as well as the required clean-out elevation. A copy of the calculations may
' be found in the Appendix F of this report.
In addition to the above, rip-rap aprons have been designed at all pipe outlets as well as
the discharge point of propose concrete flumes. The required apron sizes are shown on
the plans. A copy of the rip-rap apron calculations are also provided in Appendix F of
the report.
' Total Nitrogen and Total Phosphorus Loading Calculations
Using the NC-DENR Calculation Worksheet, provided on the NC-DENR Website, the
' total nitrogen and total phosphorus loadings from the proposed development were
calculated.
With the installation of the proposed BMP's proposed for this project -including
' stormwater wetlands, level spreaders and grass swales -the loadings have been reduced
to the following (see page G-7 of Appendix G):
Total nitrogen: 3.74 lb/ac/yr
' Total phosphorus: 0.21 lb/ac/yr
' NCDENR Worksheets
As required by NCDENR, Worksheets for the Stormwater Wetlands (ponds) and Level
Spreaders provided on the plans have been completed. A copy of the worksheets are
' provided in Appendix H of this report.
~
5

Refer to Appendix G for a copy of the NC-DENR Worksheet Spreadsheet Calculations.

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QMMENAMEMSEN

APPENDIX A
TR-55 CALCULATIONS

RUNOFF CURVE NUMBER COMPUTATION Version 2.10
Project Greenville NC User: ssp Date: 03-04-2007
County Pitt State: NC Checked: Date:
Subtitle: Pre Developed
Subarea Pre
-
--------------
-
-
---
-------- ---------------- -------------------
Hydrologic -----------------
Soil Group
COVER DESCRIPTION A B C D

----------------------------
--------------
- Acres
- (CN)

FULLY DEVELOPED URBAN AREAS -
(Veg Estab.) -
----------------- -----------------
Impervious Areas
Paved parking lots, roofs, driveways - .10(98) - -
OTHER AGRICULTURAL LANDS
Brush - brush, weed, grass m ix good - 17.4(48) - -
Woods fair - 4.21(60) - -
1
.,.~ Total Area (by Hydrologic Soil Group) 21.7
SUBAREA: Pre TOTAL DRAINAGE AREA: 21.7:1 Acres WEIGHTED CURVE NUMBER: 51*
* - Generated for use by GRAPHIC method

TIME OF CONCENTRATION AND TRAVEL TIME Version 2.10
Project Greenville NC User: ssp Date: 03 -04-2007
County Pitt State: NC Checked: Date:
Subtitle: Pre Developed
----------------------------
Flow Type 2 year Length ---------------------
Slope Surface n ------------------------
Area Wp Velocity ------
Time
rain (ft)
--------------
--
- (ft/ft) code
- (sq/ft) (ft) (ft/sec) (hr)
-
---
-------
Sheet 3.9 300 -----------------
---
.026 e ------------------------ ------
0.321
Shallow Concent'd 325 .012 u 0.051
Open Channel 1025 2 0.142
Time of Concentration = 0.51*
--- Sheet Flow Surface Codes ---
A Smooth Surface F Grass, Dense --- Shallow Concentrate d ---
B Fallow (No Res.) G Grass, Burmuda --- Surface Codes ---
C Cultivated < 20 % Res. H Woods, Light P Paved
D Cultivated > 20 $ Res. I Woods, Dense U Unpaved
E Grass-Range, Short J Range, Natural
t
*
- Generated for use by GRAPHIC method

GRAPHICAL PEAK DISCHARGE METHOD
Project Greenville NC User: ssp
County Pitt State: NC Chec ked:
Subtitle: Pre Developed
Data: Drainage Area 21.71 * A~~res
Runoff Curve Number 51
Time of Concentration: 0.51 * Hours
Rainfall Type II
Pond and Swamp Area NONE
I Storm Number 1 1
I----------------------
----- 1 2 1 3 1 4 1 5 1
I
-
I Frequency (yrs) I 1
I I------
1 2 I------
1 10 I-----
1 25 -1------1
1 100 1
I
1 24-Hr Rainfall (in) 1 3.4
I I
1 3.9 I
1 6 I
1 7 I I
1 7.9 1
I
I Ia/P Ratio 1 0.57
I I
1 0.49 I
1 0.32 I
10.27 I I
10.24 1
I
I Used 1 0.50
I I
1 0.49 I
1 0.32 I
1 0.27 i I
1 0.24 1
I
I Runoff (in) 1 0.20 I
1 0.34 I
1 1.22 I
1 1.76 I I
1 2.29 1
I I I I I I I
~ I Unit Peak Discharge 10.354 10.367 10.650 10.696 10.718 1
~ I (cfs/acre/in) i
I I I I I I
i
I Pond and Swamp Factor) 1.00 I
1 1.00 I
1 1.00 I
1 1.00 I I
1 1.00 1
I 0.0% Ponds Used I I I I I I
1----------------------1------
I Peak Discharge (cfs) 1 2 1------
1 3 I------
1 17 1-----
I 27 -1------I
1 36 1
* - Value(s) provided from TR- 55 syst em rout ines
Version 2.10
Date: 03-04-2007
Date:

RUNOFF CURVE NUMBER COMPUTATION Version 2.10
Project Greenville NC User: ssp Date: 03-04-2007
County Pitt State: NC Checked: Date:
Subtitle: Post Developed
Subarea Post
Hydrologic Soil Group
COVER DESCRIPTION A B C D
Acres (CN)
FULLY DEVELOPED URBAN AREAS (Veg Estab.)
Open space (Lawns parks etc.)
Good condition; grass cover > 750 - 2.01(61) - -
Impervious Areas
Paved parking lots, roofs, driveways - 8.98(98) - -
Total Area (by Hydrologic Soil Group) 10.9
____
~.
SUBAREA: Post TOTAL DRAINAGE AREA: 10.99 A~~res WEIGHTED CURVE NUMBER: 91*
* - Generated for use by GRAPHIC method

TIME OF CONCENTRATION AND TRAVEL TIME Version 2.10
Project Greenville NC User: ssp Date: 03 -04-2007
County Pitt State: NC Checked: Date:
Subtitle: Post Developed
-----------------------------
Flow Type 2 year Length --------------------
Slope Surface n ------------------------
Area Wp Velocity ------
Time
rain (ft) (ft/ft) code (sq/ft) (ft) (ft/sec) (hr)
----------------------------
Sheet 3.9 166 -----------
.025 ----------
a ------------------------ ------
0.025
Shallow Concent'd 200 .005 p 0.039
Open Channel 858 3 0.079
Time of Concentration = 0.14*
--- Sheet Flow Surface Codes -- -
A Smooth Surface F Grass, Dense --- Shallow Concentrate d ---
B Fallow (No Res.) G Grass, Burmuda --- Surface Codes ---
C Cultivated < 20 o Res. H Woods, Light P Paved
D Cultivated > 20 $ Res. I Woods, Dense U Unpaved
E Grass-Range, Short J Range, Natural
(1 * - Generated for use by GRAPHIC method

GRAPHICAL PEAK DISCHA:~GE METHOD
Project Greenville NC User: ssp
County Pitt State: NC Checked:
Subtitle: Post Developed
Data: Drainage Area 10.99 * Acres
Runoff Curve Number 91
Time of Concentration: 0.14 * Hours
Rainfall Type II
Pond and Swamp Area NONE
I Storm Number ( 1 1 2 1 3 1 4 1 5 1
1----------------------1------1------1------1------1------1
I Frequency (yrs) ( 1 1 2 1 10 1 25 1 100 1
I I I I I I I
1 24-Hr Rainfall (in) 1 3.4 1 3.9 1 6 1 7 1 7.9 1
I i I I I I I
I Ia/P Ratio 1 0.06 1 0.05 1 0.03 1 0.03 1 0.03 1
I I I I I I I
I Used 1 0.10 1 0.10 1 0.10 1 0.10 1 0.10 1
I I I I I I I
I Runoff (in) 1 2.45 1 2.92 1 4.96 1 5.94 1 6.83 1
~ i I I I I I I
~ I Unit Peak Discharge 11.421 11.421 11.421 11.421 11.421 1
I (cfs/acre/in) I I I I I I
I I I I I I I
1 Pond and Swamp Factor) 1.00 1 1.00 1 1.00 1 1.00 1 1.00 1
I O.Oo Ponds Used I I I I I I
I----------------------I------1------1------1------I------1
1 Peak Discharge (cfs) ( 38 1 46 1 77 1 93 1 107 1
* - Value(s) provided from TR-55 system routines
Version 2.10
Date: 03-04-2007
Date:

RUNOFF CURVE NUMBER COMPUTATION Version 2.10
Project Greenville NC User: ssp Date: 03-04-2007
County Pitt State: NC Checked: Date:
Subtitle: Post Developed - Areal
Subarea Post
-------------------------------------------------------------------------------
Hydrologic Soil Group
COVER DESCRIPTION A B C D
Acres (CN)
-------------------------------------------------------------------------------
FULLY DEVELOPED URBAN AREAS (Veg Estab.)
Open space (Lawns parks etc.)
Good condition; grass cover > 750 - 2.37(61) - -
Impervious Areas
Paved parking lots, roofs, driveways - 4.21(98) - -
,~ Total Area (by Hydrologic Soil Group) 6.58
1
-------------------------------------------------------------------------------
SUBAREA: Post TOTAL DRAINAGE AREA: 6.58 Acres WEIGHTED CURVE NUMBER: 85*
* - Generated for use by GRAPHIC method

TIME OF CONCENTRATION A'ND TRAVEL TIME Version 2.10
Project Greenville NC User: ssp Date: 03 -04-2007
County Pitt State: NC Checked: Date:
Subtitle: Post Developed - Areal
-----------------------------
Flow Type 2 year Length --------------------
Slope Surface n ------------------------
Area Wp Velocity ------
Time
rain (ft) (ft/ft) code (sq/ft) (ft) (ft/sec) (hr)
----------------------------
Sheet 3.9 160 ---------------------
.026 a ------------------------ ------
0.024
Open Channel 574 3 0.053
Time of Concentration = 0.08*
--- Sheet Flow Surface Codes ---
A Smooth Surface F Grass, Dense --- Shallow Concentrate d ---
B Fallow (No Res.) G Grass, Burmuda --- Surface Codes ---
C Cultivated < 20 o Res. H Woods, Light P Paved
D Cultivated > 20 o Res.
E G
-R
h I Woods, Dense U Unpaved
rass
ange, S
ort J Range, Natural
1

* - Generated for use by GRAPHIC method

GRAPHICAL PEAK DISCHARGE METHOD
Project Greenville NC User: ssp
County Pitt State: NC Checked:
Subtitle: Post Developed - Areal
Data: Drainage Area 6.58 * Acres
Runoff Curve Number 85
Time of Concentration: 0.08 * Hours
Rainfall Type II
Pond and Swamp Area NONE
I Storm Number 1 1
I----------------------
-- 1 2 1 3 1 4 1 5 1
1
----
I Frequency (yrs) 1 1
I I------
1 2 1------
1 10 1------
1 25 1------1
1 100 1
I
1 24-Hr Rainfall (in) 1 3.4
I I
I 3.9 I
1 6 I
1 7 I I
1 7.9 1
I
I Ia/P Ratio 1 0.10 I
1 0.09 I
1 0.06 I
1 0.05 I I
1 0.04 1
I I
I Used 10.10 I
10.10 I
1 0.10 I
10.10 I I
10.10 I

~ I I
I Runoff (in) 1 1.93
I I
1 2.37 I
1 4.30 I
15.25 I I
16.12 1
I
I Unit Peak Discharge 11.675 I
11.677 I
11.677 I
11.677 I I
11.677 1
I (cfs/acre/in) I
I I I I I I
I
1 Pond and Swamp Factor) 1.00 I
( 1.00 I
11.00 I
1 1.00 I I
1 1.00 1
I O.Oo Ponds Used I
------ I I I I I
I
----------------1------
1 Peak Discharge (cfs) 1 21 I------
1 26 I------
I 47 i------
( 58 I------1
1 67 I
Version 2.10
Date: 03-04-2007
Date:
* - Value(s) provided from TR-55 system routines

TIME OF CONCENTRATION AND TRAVEL TIME Version 2.10
Project Greenville NC User: ssp Date: 03 -04-2007
County Pitt State: N C Checked: Date:
Subtitle: Post Developed Direct
-----------------------------
Flow Type 2 year Length ----------
Slope Su ----------
rface n ------------------------
Area Wp Velocity ------
Time
rain (ft)
------------ (ft/ft) code (sq/ft) (ft) (ft/sec) (hr)
-----------------
Sheet 3.9 169 ----------
.017 ----------
e ------------------------ ------
0.240
Shallow Concent'd 300 .06 u 0.021
Open Channel 90 3 0.008
Time of Concentration = 0.27*
--- Sheet Flow Surface Codes -- -
A Smooth Surface F Grass, Dense --- Shallow Concentrated ---
B Fallow (No Res.) G Grass, Burmuda --- Surface Codes ---
C Cultivated < 20 o Res. H Woods, Light P Paved
D Cultivated > 20 ~ Res. I Woods, Dense U Unpaved

E Grass-Range, Short
s
J Range,
Natural
* - Generated for use by GRAPHIC method

GRAPHICAL PEAK DISCHARGE METHOD
Project Greenville NC User: ssp
County Pitt State: NC Chec ked:
Subtitle: Post Developed Direc t
Data: Drainage Area 4.13 * Acres
Runoff Curve Number 54
Time of Concentration: 0.27 * Hours
Rainfall Type II
Pond and Swamp Area NONE
I Storm Number I 1
1----------------------
------ 1 2
- 1 3 1 q l 5 1
I
I Frequency (yrs) 1 1
I 1
-----
1 2 1------
1 10 1-----
1 25 -1------1
1 100 1
I
1 24-Hr Rainfall (in) 1 3.4 I
I 3.9 I
1 6 I
1 7 I I
1 7.9 1

]7 I I
I Ia/P Ratio 1 0.50 i
10.44 I
1 0.28 I
1 0.24 I I
10.22 1
~ I I I I I I I

N I Used 1 0.50
I I 1 0.44
I 1 0.28
I 1 0.24
I 1 0.22 1
I I
I Runoff (in) ( 0.28
I 10.45 1 1.44 12.03 1 2.61 1
i
1 Unit Peak Discharge 10.494 I
10.668 I
10.958 I
10.991 I I
11.013 1
I (cfs/acre/in) I
i I I I I I
I
I Pond and Swamp Factor) 1.00 I
11.00 I
1 1.00 I
1 1.00 I I
1 1.00 1
I 0.0% Ponds Used I
-----
- i I I I I
I
-
---------------1------
I Peak Discharge (cfs) 1 1 1------
1 1 1------
1 6 1-----
1 8 -1------1
1 11 1
* - Value(s) provided from TR- 55 syst em routines
Version 2.10
Date: 03-04-2007
Date:

APPENDIX B
HYDRAFLOW HYDROGRAPHS
CALCULATIONS

' Hydrograph Summary Report
Page 1
Hyd.
No. Hydrograph
type
(origin) Peak
flow
(cfs) Time
interval
(min) Time to
peak
(min) Volume

(acft) Inflow
hyd(s) Maximum
elevation
(ft) Maximum
storage
(acft) Hydrograph
description
1 SCS Runoff 1.07 1 749 0.350 ---- ------ ------ Pre Developed
2 SCS Runoff 43.13 1 718 2.181 ---- ------ ------ Post Developed Area 1
3 Reservoir 0.19 1 1440 0.193 2 34.37 1.988 Post Area 1 Thru Pond
4 SCS Runoff 0.62 1 728 0.097 ---- ------ ------ Post Developed Direct
5 SCS Runoff 23.27 1 718 1.090 ---- ------ ------ Post Developed Area 2
6 Reservoir 0.17 1 1439 0.163 5 41.65 0.927 Area 2 to Pond 2
7 Combine 0.90 1 728 0.454 3, 4, 6 ------ ------ Total Post Runoff
Proj. file: GreenvilleNCRev3-1-0 .g~turn Period: 1 yr Run date: 03-05-2007
Hydraflow Hydrographs by Intelisolve

Hydrograph Plot
Hydraflow Hydrographs by Iritelisolve
Hyd. No. 1
Pre Developed
Hydrograph type =SCS Runoff
Storm frequency = 1 yrs
Drainage area = 21.71 ac
Basin Slope = 2.0
Tc method =USER
Total precip. = 3.40 in
Storm duration = 24 hrs
Peak discharge = 1.07 cfs
Time interval = 1 min
Curve number = 51
Hydraulic length = 350 ft
Time of conc. (Tc) = 30 min
Distribution = Type II
Shape factor = 484
Hydrograph Volume = 0.350 acft
1 -SCS Runoff -1 Yr - Qp = 1.07 cf s
1.5
1.
N

CJ
0.
0.
0.0 2.4 4.8 7.2 9.6 12.0 14.4 16.8 19 .2 21.6 24.0
Time (hrs)
/ Hyd. 1

---- I ---
-{
~ j
i
- 0

5
0
~`~,

1
1
1
1
1
1
1
1
1
1
1

Hydrograph Plot
Hydraflow Hydrographs by Intelisolve
Hyd. No. 2
Post Developed Area 1
Hydrograph type =SCS Runoff
Storm frequency = 1 yrs
Drainage area = 10.99 ac
Basin Slope = 3.0
Tc method =USER
Total precip. = 3.40 in
Storm duration = 24 hrs
Peak discharge = 43.13 cfs
Time interval = 1 min
Curve number = 91
Hydraulic length = 300 ft
Time of conc. (Tc) = 8 min
Distribution = Type II
Shape factor = 484
Hydrograph Volume = 2.181 acft
2 -SCS Runoff -1 Yr - Qp = 43.13 cfs
50 -
40 -
i
I
30 -- - --- - - ~
~ 20
10
0
0.0 2.1 4.2 6.3 8.4 10.5 12.6 14.7 16.8 18.9 21.0
Time (hrs)
/ Hyd. 2
3-3

Hydrograph Plot
Hydraflow Hydrographs by Intelisolve
Hyd. No. 3
Post Area 1 Thru Pond
Hydrograph type =Reservoir
Storm frequency = 1 yrs
Inflow hyd. No. = 2
Max. Elevation = 34.37 ft
Peak discharge = 0.19 cfs
Time interval = 1 min
Reservoir name =Pond
Max. Storage = 1.988 acft
Storage Indication method used.
Hydrograph Volume = 0.193 acft
3 -Reservoir -1 Yr - Qp = 0.19 cfs
50
4
N 3
U
2
1
0.0 2.4 4.8 7.2 9.6 12.0 14.4 16.8 19.2 21.6 24.0
Time (hrs)
/ Hyd. 2 /Hyd. 3

-
--
- -
p
0
0
'3- ~!

Hydrograph Plot
Hydraflow Hydrographs by Intelisolve
Hyd. No. 4
Post Developed Direct
Hydrograph type =SCS Runoff
Storm frequency = 1 yrs
Drainage area = 4.13 ac
Basin Slope = 6.0
Tc method =USER
Total precip. = 3.40 in
Storm duration = 24 hrs
Peak discharge = 0.62 cfs
Time interval = 1 min
Curve number = 54
Hydraulic length = 300 ft
Time of conc. (Tc) = 16 min
Distribution = Type II
Shape factor = 484
Hydrograph Volume = 0.097 acft
4 -SCS Runoff -1 Yr - Qp = 0.62 cfs
0
8
.
0.

~ 0
.
U
0
.
0.
0.0 2.4 4.8 7.2 9.6 12.0 14.4 16.8 19.2 21.6 24.0
Time (hrs)
/ Hyd. 4

6 --
4 ----- - --T - -
2 -

0
'S_r~

1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
Hydrograph Plot
Hydraflow Hydrographs by Intelisolve
Hyd. No. 5
Post Developed Area 2
Hydrograph type =SCS Runoff
Storm frequency = 1 yrs
Drainage area = 6.58 ac
Basin Slope = 3.0
Tc method =USER
Total precip: = 3.40 in
Storm duration = 24 hrs
Peak discharge = 23.27 cfs
Time interval = 1 min
Curve number = 85
Hydraulic length = 300 ft
Time of conc. (Tc) = 5 min
Distribution = Type II
Shape factor = 484
Hydrograph Volume = 1.090 acft
5 -SCS Runoff -1 Yr - Qp = 23.27 cfs
25
2
1
C'1
1
0.0 2.3 4.6 6.9 9.2 11.5 13.8 16.1 18.4 20.7 23.0
Time (hrs)
/ Hyd. 5
(.O
- - - ----
- - -
-- -_-
~- - - -
--
-
0
5
0
5
0

Hydrograph Plot
Hydraflow Hydrographs by Intelisolve
Hyd. No. 6
Area 2 to Pond 2
Hydrograph type =Reservoir
Storm frequency = 1 yrs
Inflow hyd. No. = 5
Max. Elevation = 41.65 ft
Peak discharge = 0.17 cfs
Time interval = 1 min
Reservoir name = Pond2
Max. Storage = 0.927 acft
Storage Indication method used.
Hydrograph Volume = 0.163 acft
6 -Reservoir -1 Yr - Qp = 0.17 cfs
25
2
~ 1

1

0.0 2.4 4.8 7.2 9.6 12.0 14 .4 16.8 19 .2 21.6 24.0
Time (hrs)
/ Hyd. 5 / Hyd. 6
- ~-
-

- - -- -
-
0
5
0
5
0
~~/

Hydrograph Plot
Hydraflow Hydrographs by Intelisolve
Hyd. No. 7
Total Post Runoff
Hydrograph type =Combine
Storm frequency = 1 yrs
Inflow hyds. = 3, 4, 6
Peak discharge = 0.90 cfs
Time interval = 1 min
Hydrograph Volume = 0.454 acft
7 -Combine -1 Yr - Qp = 0.90 cfs
1.0
0.
,~ 0.
0.
0.
0.
0.0 2.4 4.8 7.2 9.6 12.0 14.4 16.8 19.2 21.6 24.0
Time (hrs)
/ Hyd. 3 / Hyd. 4 / Hyd. 6 /Hyd. 7
". i
s _.. . _ . '. __ .._ _.. _ _.
,

i i

~- ~

' H d ro ra h S u m m a Re o rt Page 1
Y g p rY p
Hyd.
No. Hydrograph
type
(origin) Peak
flow
(cfs) Time
interval
(min) Time to
peak
(min) Volume

(acft) Inflow
hyd(s) Maximum
elevation
(ft) Maximum
storage
(acft) Hydrograph
description
1 SCS Runoff 2.80 1 739 0.602 ---- ------ ------ Pre Developed
2 SCS Runoff 50.96 1 718 2.605 ---- ------ ------ Post Developed Area 1
3 Reservoir 0.20 1 1440 0.212 2 34.92 2.393 Post Area 1 Thru Pond
4 SCS Runoff 1.40 1 726 0.156 ---- ------ ------ Post Developed Direct
5 SCS Runoff 28.33 1 717 1.338 ---- ------ ------ Post Developed Area 2
6 Reservoir 0.27 1 1396 0.222 5 42.10 1.116 Area 2 to Pond 2
7 Combine 1.71 1 726 0.590 3, 4, 6 ------ ----- Total Post Runoff
Proj. file: GreenvilleNCRev3-1-0 .g~turn Period: 2 yr Run date: 03-05-2007
Hydraflow Hydrographs by Intelisolve
~~

1
1

L
Hydrograph Plot
Hydraflow Hydrographs by Intelisolve
Hyd. No. 1
Pre Developed
Hydrograph type =SCS Runoff
Storm frequency = 2 yrs
Drainage area = 21.71 ac
Basin Slope = 2.0
Tc method = USER
Total precip. = 3.90 in
Storm duration = 24 hrs
Peak discharge = 2.80 cfs
Time interval = 1 min
Curve number = 51
Hydraulic length = 350 ft
Time of conc. (Tc) = 30 min
Distribution = Type II
Shape factor = 484
Hydrograph Volume = 0.602 acft
1 -SCS Runoff - 2 Yr - Qp = 2.80 cfs
3.0
2.
2.
~ 1.
U
1.
0.
0.
0.0 2.4 4.8 7.2 9.6 12.0 14.4 16.8 19.2 21.6 24.0
Time (hrs)
/ Hyd. 1
~~~
-
-- ~ - -
---~ - -

5
0
0
5
0

1
1
1
1
1
1
1
1
1
1
1
1
1
Hydrograph Plot
Hydraflow Hydrographs by Intelisolve
Hyd. No. 2
Post Developed Area 1
Hydrograph type =SCS Runoff
Storm frequency = 2 yrs
Drainage area = 10.99 ac
Basin Slope = 3.0
Tc method =USER
Total precip. = 3.90 in
Storm duration = 24 hrs
Peak discharge = 50.96 cfs
Time interval = 1 min
Curve number = 91
Hydraulic length = 300 ft
Time of conc. (Tc) = 8 min
Distribution = Type II
Shape factor = 484
Hydrograph Volume = 2.605 acft
2 -SC S Ru noff - 2 Y r - Qp = 50 .96 c fs
60
5
4
~
3

C~
i
2
1

0.0 2.1 4.2 6.3 8.4 10 .5 12.6 14.7 16.8 18 .9 21.0
Time (hr s)
/ Hyd. 2
"ll

- - _---- - ----- ---

0
0
p
0
0
0

1
Hydrograph Plot
Hydraflow Hydrographs by Intelisolve
Hyd. No. 3
Post Area 1 Thru Pond
Hydrograph type =Reservoir
Storm frequency = 2 yrs
Inflow hyd. No. = 2
Max. Elevation = 34.92 ft
Peak discharge = 0.20 cfs
Time interval = 1 min
Reservoir name =Pond
Max. Storage = 2.393 acft
Storage Indication method used.
Hydrograph Volume = 0.212 acft
3 -R eser voir - 2 Yr - Qp = 0.2 0 cfs
60
5
4
~
3
U
2
1

0.0 2.4 4.8 7.2 9.6 12.0 14 .4 16 .8 9 .0
Time (hrs)
/ Hyd. 2 / Hyd. 3
't3-t2

-~ -
i

--- i
----
-~
-- -. - -
--
------
~
-- -----

-

1 0
0
0
0
0
0
.2 21.6 24

Hydrograph Plot
Hydraflow Hydrographs by Intelisolve
Hyd. No. 4
Post Developed Direct
Hydrograph type =SCS Runoff
Storm frequency = 2 yrs
Drainage area = 4.13 ac
Basin Slope = 6.0
Tc method =USER
Total precip. = 3.90 in
Storm duration = 24 hrs
Peak discharge = 1.40 cfs
Time interval = 1 min
Curve number = 54
Hydraulic length = 300 ft
Time of conc. (Tc) = 16 min
Distribution = Type II
Shape factor = 484
Hydrograph Volume = 0.156 acft
4-SCS Runoff-2Yr-Qp = 1.40 cfs
1.5
1.
0.
0.
0.0 2.4 4.8 7.2 9.6 12.0 14.4 16.8 19.2 21.6 24.0
Time (hrs)
/ Hyd. 4
- --

-
i
i
p
5
0
~-t3

1
1
1
1
1
1
1
1
1
1
1
1
Hydrograph Plot
Hydraflow Hydrographs by Intelisolve
Hyd. No. 5
Post Developed Area 2
Hydrograph type =SCS Runoff
Storm frequency = 2 yrs
Drainage area = 6.58 ac
Basin Slope = 3.0
Tc method =USER
Total precip: = 3.90 in
Storm duration = 24 hrs
Peak discharge = 28.33 cfs
Time interval = 1 min
Curve number = 85
Hydraulic length = 300 ft
Time of conc. (Tc) = 5 min
Distribution = Type II
Shape factor = 484
Hydrograph Volume = 1.338 acft
5-SCS Runoff-2Yr-Qp=28.33 cfs
30
25 --- -
20 --
~ 15 - -- - ----- ---- - - --- ---
10
5 -~
0
0.0 2.2 4.4 6.6 8.8 11.0 13.2 15.4 17.6 19.8 22.0
Time (hrs)
/ Hyd. 5
~•t~

1
1
1
1
1
1
1
1
1
I
1
1
1
1
1
1
1
1
1
Hydrograph Plot
Hydraflow Hydrographs by Intelisolve
Hyd. No. 6
Area 2 to Pond 2
Hydrograph type =Reservoir
Storm frequency = 2 yrs
Inflow hyd. No. = 5
Max. Elevation = 42.10 ft
Storage Indication method used.
Peak discharge = 0.27 cfs
Time interval = 1 min
Reservoir name = Pond2
Max. Storage = 1.116 acft
Hydrograph Volume = 0.222 acft
6 -Reservoir - 2 Yr - Qp = 0.27 cfs
30
2
2
~ 1
1
0.0 2.4 4.8 7.2 9.6 12.0 14.4 16.8 19.2 21.6 .0
Time (hrs)
/ Hyd. 5 /Hyd. 6
$~tS

--

-

5
0
0
5
0
24

1
1
1
1
1
1
1
1
1
1
1
1
Hydrograph Plot
Hydraflow Hydrographs by Intelisolve
Hyd. No. 7
Total Post Runoff
Hydrograph type =Combine
Storm frequency = 2 yrs
Inflow hyds. = 3, 4, 6
Peak discharge = 1.71 cfs
Time interval = 1 min
Hydrograph Volume = 0.590 acft
7 -Combine - 2 Yr - Qp = 1.71 cfs
2.0
1.
~ 1.
C1
0.
0.
0.0 2.4 4.8 7.2 9.6 12.0 14.4 16.8 19.2 21.6 .0
Time (hrs)
/ Hyd. 3 / Hyd. 4 / Hyd. 6 /Hyd. 7
~-e ~
----
-
--
-
--
5
0
0
24

Hydrograph Summary Report
D

0
1
u
1

u
ii

1
1
0

Page 1
Hyd.
No. Hydrograph
type
(origin) Peak
flow
(cfs) Time
interval
(min) Time to
peak
(min) Volume

(acft) Inflow
hyd(s) Maximum
elevation
(ft) Maximum
storage
(acft) Hydrograph
description
1 SCS Runoff 18.98 1 734 2.176 ---- ------ ------ Pre Developed
2 SCS Runoff 83.58 1 718 4.421 ---- ------ ------ Post Developed Area 1
3 Reservoir 3.41 1 800 1.759 2 35.68 2.998 Post Area 1 Thru Pond
4 SCS Runoff 6.85 1 724 0.499 ---- ------ ------ Post Developed Direct
5 SCS Runoff 50.00 1 717 2.430 ---- ------ ------ Post Developed Area 2
6 Reservoir 2.47 1 779 1.117 5 42.90 1.495 Area 2 to Pond 2
7 Combine 9.14 1 726 3.375 3, 4, 6 ------ ------ Total Post Runoff
Proj. file: GreenvilleNCRev3-1-0 .gl~turn Period: 10 yr Run date: 03-05-2007
~Q Hydratlow Hydrograpns by inteusoive
"~'

Hydrograph Plot
Hydraflow Hydrographs by Intelisolve
Hyd. No. 1
Pre Developed
Hydrograph type =SCS Runoff
Storm frequency = 10 yrs
Drainage area = 21.71 ac
Basin Slope = 2.0
Tc method =USER
Total precip. = 6.00 in
Storm duration = 24 hrs
Peak discharge = 18.98 cfs
Time interval = 1 min
Curve number = 51
Hydraulic length = 350 ft
Time of conc. (Tc) = 30 min
Distribution = Type II
Shape factor = 484
Hydrograph Volume = 2.176 acft
1 -SCS Runoff -10 Yr - Qp = 18.98 cfs
20
1
rn
~ 1
C3~
0.0 2.4 4.8 7.2 9.6 12.0 14.4 16.8 19.2 21.6 2.0
Time (hrs)
/ Hyd. 1

_ _ ''
1 I

~ ° I St!

1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
Hydrograph Plot
Hydraflow Hydrographs by Intelisolve
Hyd. No. 2
Post Developed Area 1
Hydrograph type =SCS Runoff
Storm frequency = 10 yrs
Drainage area = 10.99 ac
Basin Slope = 3.0
Tc method =USER
Total precip. = 6.00 in
Storm duration = 24 hrs
Peak discharge = 83.58 cfs
Time interval = 1 min
Curve number = 91
Hydraulic length = 300 ft
Time of conc. (Tc) = 8 min
Distribution = Type II
Shape factor = 484
Hydrograph Volume = 4.421 acft
2 -SCS Runoff -10 Yr - Qp = 83.58 cfs
100
80 -- -
j ~ 60 -- - - ---
c.~ ~
U
40 ~
20 ~
0
0 2 4 6 8 10 12 14 16 18 20
Time (hrs)
/ Hyd. 2
~-tq

t
1
1
1
1
1
1
1

1
1
Hydrograph Plot
Hydraflow Hydrographs by Intelisolve
Hyd. No. 3
Post Area 1 Thru Pond
Hydrograph type =Reservoir
Storm frequency = 10 yrs
Inflow hyd. No. = 2
Max. Elevation = 35.68 ft
Peak discharge = 3.41 cfs
Time interval = 1 min
Reservoir name =Pond
Max. Storage = 2.998 acft
Storage Indication method used.
Hydrograph Volume = 1.759 acft
3-Reservoir-10Yr-Qp=3.41 cfs
100
8
6
4
2
0.0 2.4 4.8 7.2 9.6 12.0 14.4 16.8 19.2 21.6 24.0
Time (hrs)
/ Hyd. 2 /Hyd. 3
'~' 2 ~

---
- ----- - ----
-
I

0
0
0
0

ii

1
Hydrograph Plot
Hydraflow Hydrographs by Intelisolve
Hyd. No. 4
Post Developed Direct
Hydrograph type =SCS Runoff
Storm frequency = 10 yrs
Drainage area = 4.13 ac
Basin Slope = 6.0
Tc method =USER
Total precip: = 6.00 in
Storm duration = 24 hrs
Peak discharge = 6.85 cfs
Time interval = 1 min
Curve number = 54
Hydraulic length = 300 ft
Time of conc. (Tc) = 16 min
Distribution = Type II
Shape factor = 484
Hydrograph Volume = 0.499 acft
4-SCS Runoff-10Yr-Qp=6.85 cfs
8
v
I
0.0 2.4 4.8 7.2 9.6 12.0 14.4 16.8 19.2 21.6 24.0
Time (hrs)
/ Hyd. 4
'R ~ 2~

6
4 -- -- -- -- ----

2

0

Hydrograph Plot
Hydraflow Hydrographs by Intelisolve
Hyd. No. 5
Post Developed Area 2
Hydrograph type =SCS Runoff
Storm frequency = 10 yrs
Drainage area = 6.58 ac
Basin Slope = 3.0
Tc method =USER
Total precip. = 6.00 in
Storm duration = 24 hrs
Peak discharge = 50.00 cfs
Time interval = 1 min
Curve number = 85
Hydraulic length = 300 ft
Time of conc. (Tc) = 5 min
Distribution = Type II
Shape factor = 484
Hydrograph Volume = 2.430 acft
5 -SCS Runoff -10 Yr - Qp = 50.00 cfs
60
50
~ 30 --- - ---- - -- -- - -- -- ---
U
20 -
10
0
0 2 4 6 8 10 12 14 16 18 20
Time (hrs)
/ Hyd. 5

Hydrograph Plot
Hydraflow Hydrographs by Intelisolve
1
1
1
1
1
1
t
1
1
1
1
Hyd. No. 6
Area 2 to Pond 2
Hydrograph type =Reservoir
Storm frequency = 10 yrs
Inflow hyd. No. = 5
Max. Elevation = 42.90 ft
Peak discharge = 2.47 cfs
Time interval = 1 min
Reservoir name = Pond2
Max. Storage = 1.495 acft
Storage Indication method used.
Hydrograph Volume = 1.117 acft
6 -Reservoir -10 Yr - Qp = 2.47 cfs
60
50 -
40 ---
~ 30 -- -- - ---- -- ----- -- --- -----
C~
20
10
0
0.0 2.4 4.8 7.2 9.6 12.0 14.4 16.8 19.2 21.6 24.0
Time (hrs)
/ Hyd. 5 /Hyd. 6
~- ~

Hydrograph Plot
Hydraflow Hydrographs by Intelisolve
Hyd. No. 7
Total Post Runoff
Hydrograph type =Combine
Storm frequency = 10 yrs
Inflow hyds. = 3, 4, 6
Peak discharge = 9.14 cfs
Time interval = 1 min
Hydrograph Volume = 3.375 acft
1
1
1
1
1
7 -Combine -10 Yr - Qp = 9.14 cfs
10
0.0 2.4 4.8 7.2 9.6 12.0 14.4 16.8 19.2 21.6 24.0
Time (hrs)
/ Hyd. 3 / Hyd. 4 / Hyd. 6 /Hyd. 7
~- ~`~
I
I
__.
4
2
0

' Hydrograph Summary Report

Page 1
Hyd.
No. Hydrograph
type
(origin) Peak
flow
(cfs) Time
interval
(min) Time to
peak
(min) Volume

(acft) Inflow
hyd(s) Maximum
elevation
(ft) Maximum
storage
(acft) Hydrograph
description
1 SCS Runoff 30.06 1 733 3.148 ---- ------ ------ Pre Developed
2 SCS Runoff 98.95 1 718 5.296 ---- ------ ------ Post Developed Area 1
3 Reservoir 6.21 1 759 2.610 2 36.13 3.376 Post Area 1 Thru Pond
4 SCS Runoff 10.15 1 724 0.704 ---- ------ ------ Post Developed Direct
5 SCS Runoff 60.32 1 717 2.967 ---- ------ ------ Post Developed Area 2
6 Reservoir 3.36 1 768 1.652 5 43.49 1.802 Area 2 to Pond 2
7 Combine 17.58 1 726 4.966 3, 4, 6 ------ ------ Total Post Runoff
Proj. file: GreenvilleNCRev3-1-0 .g~turn Period: 25 yr Run date: 03-05-2007
~~,~ Hydraflow Hydrographs by Intelisolve

Hydrograph Plot
Hydraflow Hydrographs by Intelisolve
Hyd. No. 1
Pre Developed
Hydrograph type =SCS Runoff
Storm frequency = 25 yrs
Drainage area = 21.71 ac
Basin Slope = 2.0
Tc method =USER
Total precip. = 7.00 in
Storm duration = 24 hrs
Peak discharge = 30.06 cfs
Time interval = 1 min
Curve number = 51
Hydraulic length = 350 ft
Time of conc. (Tc) = 30 min
Distribution = Type II
Shape factor = 484
Hydrograph Volume = 3.148 acft
1 -SCS Runoff - 25 Yr - Qp = 30.06 cfs
40
rn
CJ
0.0 2.4 4.8 7.2 9.6 12.0 14.4 16.8 19.2 21.6 24.0
Time (hrs)
/ Hyd. 1

30
20
-
-- --
---- -_ ---
---
-- - -
--
-
-
10
I
0
~- a c~

1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
Hydrograph Plot
Hydraflow Hydrographs by Intelisolve
Hyd. No. 2
Post Developed Area 1
Hydrograph type =SCS Runoff
Storm frequency = 25 yrs
Drainage area = 10.99 ac
Basin Slope = 3.0
Tc method =USER
Total precip: = 7.00 in
Storm duration = 24 hrs
Peak discharge = 98.95 cfs
Time interval = 1 min
Curve number = 91
Hydraulic length = 300 ft
Time of conc. (Tc) = 8 min
Distribution = Type II
Shape factor = 484
Hydrograph Volume = 5.296 acft
2 -SCS Runoff - 25 Yr - Qp = 98.95 cfs
100
80 -
60
~ 40
20
0
0 2 4 6 8 10 12 14 16 18 20
Time (hrs)
/ Hyd. 2
~ a~

Hydrograph Plot
Hydraflow Hydrographs by Intelisolve
Hyd. No. 3
Post Area 1 Thru Pond
Hydrograph type =Reservoir
Storm frequency = 25 yrs
Inflow hyd. No. = 2
Max. Elevation = 36.13 ft
Peak discharge = 6.21 cfs
Time interval = 1 min
Reservoir name =Pond
Max. Storage = 3.376 acft
Storage Indication method used.
Hydrograph Volume = 2.610 acft
3 -Reservoir - 25 Yr - Qp = 6.21 cf s
100

0.0 2.4 4.8 7.2 9. 6 12.0 14 .4 16.8 19 .2 21.6 24.0
Tim e (hrs)
/ Hyd. 2 / Hyd. 3

80 ------{ ------ -----
60 ---- ~ -~ ---- - --- ---
40 --
20
0

~' ~ i

1
1
1
1
1
1
1
1
1
1
1
1
1
Hydrograph Plot
Hydraflow Hydrographs by Intelisolve
Hyd. No. 4
Post Developed Direct
Hydrograph type =SCS Runoff
Storm frequency = 25 yrs
Drainage area = 4.13 ac
Basin Slope = 6.0
Tc method =USER
Total precip. = 7.00 in
Storm duration = 24 hrs
Peak discharge = 10.15 cfs
Time interval = 1 min
Curve number = 54
Hydraulic length = 300 ft
Time of conc. (Tc) = 16 min
Distribution = Type II
Shape factor = 484
Hydrograph Volume = 0.704 acft
4 -SCS Runoff - 25 Yr - Qp = 10.15 cfs
15
1
C3~
0.0 2.4 4.8 7.2 9.6 12.0 14.4 16.8 9. 6 .0
Time (hrs)
/ Hyd. 4
6- a~
~ --

1 0
5
0
2 21. 24

Hydrograph Plot
Hydraflow Hydrographs by Intelisolve
Hyd. No. 5
Post Developed Area 2
Hydrograph type =SCS Runoff
Storm frequency = 25 yrs
Drainage area = 6.58 ac
Basin Slope = 3.0
Tc method =USER
Total precip. = 7.00 in
Storm duration = 24 hrs
Peak discharge = 60.32 cfs
Time interval = 1 min
Curve number = 85
Hydraulic length = 300 ft
Time of conc. (Tc) = 5 min
Distribution = Type II
Shape factor = 484
Hydrograph Volume = 2.967 acft
--~
5 -SCS Runoff - 25 Yr - Qp = 60.32 cfs
80
C~
0 2 4 6 8 10 12 14 16 18 20
Time (hrs)
/ Hyd. 5

60 { -
40 - ----- ~ --- -- -- --- --- ---
20

0
~'~

Hydrograph Plot
Hydraflow Hydrographs by Intelisolve
Hyd. No. 6
Area 2 to Pond 2
Hydrograph type =Reservoir
Storm frequency = 25 yrs
Inflow hyd. No. = 5
Max. Elevation = 43.49 ft
Peak discharge = 3.36 cfs
Time interval = 1 min
Reservoir name = Pond2
Max. Storage = 1.802 acft
Storage Indication method used.
Hydrograph Volume = 1.652 acft
6 -Reservoir - 25 Yr - Qp = 3.36 cfs
80
6
N
~ 4
CI
2
0.0 2.4 4.8 7.2 9.6 12.0 14.4 16.8 19.2 21.6 24.0
Time (hrs)
/ Hyd. 5 /Hyd. 6
--- ~
~~
I -

-- --
--
o
0
0
0
S-3

Hydrograph Plot
Hydraflow Hydrographs by Intelisolve
Hyd. No. 7
Total Post Runoff
Hydrograph type =Combine
Storm frequency = 25 yrs
Inflow hyds. = 3, 4, 6
Peak discharge = 17.58 cfs
Time interval = 1 min
Hydrograph Volume = 4.966 acft
7 -Combine - 25 Yr - Qp = 17.58 cfs
20
1
i
N
~ 1
C~
I
0.0 2.4 4.8 7.2 9.6 12.0 14.4 16.8 19.2 .0
Time (hrs)
/ Hyd. 3 / Hyd. 4 / Hyd. 6 /Hyd. 7

i
i

1 5
5
0
.6 24
~` 32

Hydrograph Summary Report Page,

Hyd.
No. Hydrograph
type
(origin) Peak
flow
(cfs) Time
interval
(min) Time to
peak
(min) Volume

(acft) Inflow
hyd(s) Mazimum
elevation
(ft) Maximum
storage
(acft) Hydrograph
description
1 SCS Runoff 41.15 1 732 4.113 ---- ------ ------ Pre Developed
2 SCS Runoff 112.72 1 718 6.087 ---- ------ ------ Post Developed Area 1
3 Reservoir 8.24 1 753 3.383 2 36.62 3.820 Post Area 1 Thru Pond
4 SCS Runoff 13.36 1 724 0.905 ---- ------ ------ Post Developed Direct
5 SCS Runoff 69.58 1 717 3.455 ---- ------ ------ Post Developed Area 2
6 Reservoir 9.55 1 729 2.138 5 43.77 1.951 Area 2 to Pond 2
7 Combine 29.25 1 726 6.426 3, 4, 6 ------ ------ Total Post Runoff
Proj. file: GreenvilleNCRev3-1-0 .g~turn Period: 100 yr Run date: 03-05-2007
~~ ~,~ Hydraflow Hydrographs by Intelisolve

Hydrograph Plot
Hydraflow Hydrographs by Intelisolve
Hyd. No. 1
Pre Developed
Hydrograph type =SCS Runoff
Storm frequency = 100 yrs
Drainage area = 21.71 ac
Basin Slope = 2.0
Tc method =USER
Total precip. = 7.90 in
Storm duration = 24 hrs
Peak discharge = 41.15 cfs
Time interval = 1 min
Curve number = 51
Hydraulic length = 350 ft
Time of conc. (Tc) = 30 min
Distribution = Type II
Shape factor = 484
Hydrograph Volume = 4.113 acft
1 -SCS Runoff -100 Yr - Qp = 41.15 cfs
50
4
3
U
2
'I
0.0 2.4 4.8 7.2 9.6 12.0 14.4 16.8 19.2 21.6 24.0
Time (hrs)
/ Hyd. 1

~ ~
-----
I -- ---

--

--

0
0
0
0
0
~~ 3y

Hydrograph Plot
Hydraflow Hydrographs by Intelisolve
Hyd. No. 2
Post Developed Area 1
Hydrograph type =SCS Runoff
Storm frequency = 100 yrs
Drainage area = 10.99 ac
Basin Slope = 3.0
Tc method =USER
Total precip. = 7.90 in
Storm duration = 24 hrs
Peak discharge = 112.72 cfs
Time interval = 1 min
Curve number = 91
Hydraulic length = 300 ft
Time of conc. (Tc) = 8 min
Distribution = Type II
Shape factor = 484
Hydrograph Volume = 6.087 acft
2 -SCS Runoff -100 Yr - Qp = 112.72 cfs
150
10
rn
U
5
0 2 4 6 8 10 12 14 16 18 20
Time (hrs)
/ Hyd. 2
i

0
0
0
8.35

1
1
1
1
1
1
1

1
Hydrograph Plot
Hydraflow Hydrographs by Intelisolve
Hyd. No. 3
Post Area 1 Thru Pond
Hydrograph type =Reservoir
Storm frequency = 100 yrs
Inflow hyd. No. = 2
Max. Elevation = 36.62 ft
Peak discharge = 8.24 cfs
Time interval = 1 min
Reservoir name =Pond
Max. Storage = 3.820 acft
Storage Indication method used.
Hydrograph Volume = 3.383 acft
3 -Reservoir -100 Yr - Qp = 8.24 cfs
150
I
100
50
i
0
0.0 2.4 4.8 7.2 9.6 12.0 14.4 16.8 19.2 21.6 24.0
Time (hrs)
/ Hyd. 2 /Hyd. 3
'x-34

1
1
1
Hydrograph Plot
Hydraflow Hydrographs by Intelisolve
Hyd. No. 4
Post Developed Direct
Hydrograph type =SCS Runoff
Storm frequency = 100 yrs
Drainage area = 4.13 ac
Basin Slope = 6.0
Tc method =USER
Total precip. = 7.90 in
Storm duration = 24 hrs
Peak discharge = 13.36 cfs
Time interval = 1 min
Curve number = 54
Hydraulic length = 300 ft
Time of conc. (Tc) = 16 min
Distribution = Type II
Shape factor = 484
Hydrograph Volume = 0.905 acft
4 -SCS Runoff -100 Yr - Qp = 13.36 cfs
15
1
U
I
0.0 2.4 4.8 7.2 9.6 12.0 14.4 16.8 19.2 21.6 24.0
Time (hrs)
/ Hyd. 4
'~• 3'-
i
-. ~ . ~'. -~ _ _ I '.. .._ ~-
~. '' .

1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
Hydrograph Plot
Hydraflow Hydrographs by Intelisolve
Hyd. No. 5
Post Developed Area 2
Hydrograph type =SCS Runoff
Storm frequency = 100 yrs
Drainage area = 6.58 ac
Basin Slope = 3.0
Tc method =USER
Total precip: = 7.90 in
Storm duration = 24 hrs
Peak discharge = 69.58 cfs
Time interval = 1 min
Curve number = 85
Hydraulic length = 300 ft
Time of conc. (Tc) = 5 min
Distribution = Type II
Shape factor = 484
Hydrograph Volume = 3.455 acft
5 -SCS Runoff -100 Yr - Qp = 69.58 cfs
80 -
60 ---
40 - - - -- -
20
0
0 2 4 6 8 10 12 14 16 18 20
Time (hrs)
/ Hyd. 5
~- 35~

1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
Hydrograph Plot
Hydraflow Hydrographs by Intelisolve
Hyd. No. 6
Area 2 to Pond 2
Hydrograph type =Reservoir
Storm frequency = 100 yrs
Inflow hyd. No. = 5
Max. Elevation = 43.77 ft
Storage Indication method used.
Peak discharge = 9.55 cfs
Time interval = 1 min
Reservoir name = Pond2
Max. Storage = 1.951 acft
Hydrograph Volume = 2.138 acft
6 -Reservoir -100 Yr - Qp = 9.55 cfs
80
6
~ 4
C'1
2
0.0 2.4 4.8 7.2 9.6 12.0 14.4 16.8 19.2 21.6 24.0
Time (hrs)
/ Hyd. 5 /Hyd. 6
B- ~
i
p - - --
i
0
0

Hydrograph Plot
Hydraflow Hydrographs by Intelisolve
Hyd. No. 7
Total Post Runoff
Hydrograph type =Combine
Storm frequency = 100 yrs
Inflow hyds. = 3, 4, 6
Peak discharge = 29.25 cfs
Time interval = 1 min
Hydrograph Volume = 6.426 acft
7 -Combine - 100 Yr - Qp = 29.25 cfs
30
2
2
~ 1
1
0.0 2.4 4.8 7.2 9.6 12.0 14.4 16.8 19.2 21.6 .0
Time (hrs)
/ Hyd. 3 / Hyd. 4 / Hyd. 6 /Hyd. 7

- -
~
--
- -
---

0
5
0
5
0
24
~" ~p

Reservoir Report
Page 1
Reservoir No. 1 -Pond Hydraflow Hydrographs by Intelisolve
Pond Data
Pond storage is based on known contour areas. Average end area method used.
Stage /Storage Table
Stage (ft) Elevation (ft) Contour area (sgft) Incr. Storage (acft) Total storage (acft)
0.00 31.00 20,344 0.000 0.000
1.00 32.00 23,384 0.502 0.502
2.00 33.00 26,574 0.573 1.075
3.00 34.00 29,874 0.648 1.723
4.00 35.00 33,290 0.725 2.448
5.00 36.00 37,504 0.813 3.261
6.00 37.00 40,712 0.898 4.159
7.00 38.00 43,978 0.972 5.131
8.00 39.00 47,300 1.048 6.179
Culvert / Orifice Structure s Weir Structures
IAl IBl [Cl IDl IA] IB] [C] LD]
Rise in = 18.0 2.0 12.0 0.0 Crest Len ft = 12.56 15.00 0.00 0.00
Span in = 18.0 2.0 12.0 0.0 Crest EI. ft = 36.75 37.00 0.00 0.00
No. Barrels = 2 1 2 0 Weir Coeff. = 3.33 3.33 0.00 0.00
Invert EI. ft = 31.00 31.00 35.00 0.00 Weir Type =Riser Rect --- ---
Length ft = 73.0 0.0 0.0 0.0 Multi-Stage =Yes No No No
Slope % = 4.00 0.00 0.00 0.00
N-Value = .013 .013 .013 .000
Orif. Coeff. = 0.60 0.60 0.60 0.00
Multi-Stage = n/a Yes Yes No Exfiltration Rate = 0.00 in/hr/sgft Tailwater Elev. = 0.00 ft
Note: All outflows have been analyzed under inlet and outlet control.
Stage /Storage /Discharge Table
Stage Storage Elevation Clv A Clv B Clv C Clv D Wr A Wr B Wr C Wr D Exfil Total
ft acft ft cfs cfs cfs cfs cfs cfs cfs cfs cfs cfs
0.00 0.000 31.00 0.00 0.00 0.00 --- 0.00 0.00 --- --- --- 0.00
1.00 0.502 32.00 0.10 0.10 0.00 --- 0.00 0.00 --- --- --- 0.10
2.00 1.075 33.00 0.14 0.14 0.00 --- 0.00 0.00 --- -- --- 0.14
3.00 1.723 34.00 0.18 0.18 0.00 --- 0.00 0.00 --- -- -- 0.18
4.00 2.448 35.00 0.22 0.21 0.00 --- 0.00 0.00 --- --- --- 0.21
5.00 3.261 36.00 5.61 0.22 5.35 -- 0.00 0.00 -- --- --- 5.56
6.00 4.159 37.00 14.71 0.22 9.26 --- 5.23 0.00 --- --- --- 14.71
7.00 5.131 38.00 41.58 0.06 4.00 --- 37.52 49.95 --- -- --- 91.52
8.00 6.179 39.00 45.59 0.03 2.02 --- 43.53 141.28 --- --- --- 186.86
~~I

I
1
1
1
1
1
1
1
1
1
1
1
Pond 2

a~

0
6 -- -
4 - ---
2

~
nn n ~a ~ ~~ ~ nQ ~ n~ ~ Qn ~ ~~ ~ ~~

Storage (acft)
6.07
~-~2

Po nd- 2
8

/Total
/ Culv A
~ / Culv B

~ / Culv C

~ / Culv D
/Weir A
/ Weir B
/ Weir C
/ Weir D

4. 02 66. 02 88. 03 110 .04 132 .05 154 .05 176 .06 / E~Itration
Dis charge (cfs)

6 - - -
4 - _ _

2
0

0.00 22. 01 4
~ - X13

Reservoir Report
Page 1
' ReSerVOlr No. 2 - POnd2 Hydraflow Hydrographs by Intelisolve
Pond Data
Pond storage is based on known contour areas. Avera ge end area method used.
' Stage /Storage Table
Stage (ft) Elevation (ft) Co ntour area (sgft) Incr. Storage (acft) Total storage (acft)
0.00 39.00 12,197 0.000 0.000
1.00 40.00 14,296 0.304 0.304
2.00 41.00 16,656 0.355 0.659
3.00 42.00 19,101 0.410 1.070
4.00 43.00 22,057 0.472 1.542
5.00 44.00 24,157 0.530 2.073
6.00 45.00 26,315 0.579 2.652
7.00 46.00 28,529 0.630 3.282
Culvert /Orifice Structures Weir Structures
'
IAl IBl [Cl IDl IAl IBl [Cl IDI
Rise in = 18.0 2.0 6.0 0.0 Crest Len ft = 12.46 10.00 0.00 0.00
Span in = 18.0 2.0 6.0 0.0 Crest EI. ft = 43.50 44.00 0.00 0.00
'
No. Barrels = 1 1 3 0 Weir Coeff. = 3.33 3.33 0.00 0.00
Invert EI. ft = 39.00 39.00 42.00 0.00 Weir Type =Riser Rect --- ---
Length ft = 200.0 0.0 0.0 0.0 Multi-Stage =Yes No No No
Slope % = 0.50 0.00 0.00 0.00
'
N-Value = .013 .013 .013 .000
Orif. Coeff. = 0.60 0.60 0.60 0.00
Multi-Stage = n/a Yes Yes No Exfiltration Rate = 0.00 in/hr/sgft Tailwater Elev. = 0.00 ft
Note: All outFlows have been analyzed under inlet and outlet control.
Stage /Storage /Discharge Table
Stage Storage Elevation Clv A Clv B Clv C Clv D Wr A Wr B Wr C Wr D Exfil Total
ft acft ft cfs cfs cfs cfs cfs cfs cfs cfs cfs cfs
'
0.00 0.000 39.00 0.00 0.00 0.00 0.00 0.00 0.00
1.00 0.304 40.00 0.10 0.10 0.00 --- 0.00 0.00 --- --- --- 0.10
2.00 0.659 41.00 0.14 0.14 0.00 --- 0.00 0.00 --- --- --- 0.14
3.00 1.070 42.00 0.18 0.18 0.00 0.00 0.00 --- - 0.18
'
4.00 1.542 43.00 2.66 0.19 2.46 =_=
0.00 0.00 _
_ ~= 2.65
5.00 2.073 44.00 12.99 0.05 1.29 11.66 0.00 12.99
6.00 2.652 45.00 14.69 0,01 0.32 --- 14.31 33.30 --- --- --- 47.95
7.00 3.282 46.00 15.98 0.01 0.17 --- 15.65 94.19 --- --- --- 110.02
~ ~' `+a

Pond2
8
6 - --
~, 4 - --
2
0
0.0 0.4 0.8 1.2 1.6 2.0 2.4 2.8 3.2
Storage (acft)
8 - y 5'

Pond2
a~
m

6
4 -

2 - -~
i - --
0

U.0 12.9 25.7 38.6 51.5 64.3 77.2 90.1 102.9
Discharge (cfs)
/ Total
/ Culv A
/ Culv B
/ Culv C
/ Culv D
/ Weir A
/ Weir B
/ Weir C
/ Weir D
/ Exfiltration
~-~{t~

i

1
1
APPENDIX C
FOREBAY AND POND CALCULATIONS

u
i.

POND "1"
NCDENR DWQ WET DETENTION BASIN CALCULATIONS
Project Name: Lowes of Greenville, NC
Project No.:
Date: 3/5/2007
BASIN INFORMATION
TOTAL AREA DRAINING TO POND (DA)= 478,724 SF = 10.99 AC
IMPERVIOUS SURFACES DRAINING TO POND = 391,169 SF
DRAINAGE AREA PERCENT IMPERVIOUS (%IMP) = 81.7%
NORMAL POOL SURFACE AREA REQUIREMENTS
(Based on 85 % TSS Removal Chart, No Vegetated Filter)
POND DEPTH = 3 FT
SA/DA % = 3.37 (FROM Table 1.1,DENR)
SURFACE AREA REQUIRED = 16,133 SF
SURFACE AREA PROVIDED = 20,344 SF @ ELEVATION 31
Therefore, Normal Pool surface area is ADEQUATE
8.98 AC
~'

i
POND "1"
POND AND FOREBAY VOLUMES BELOW NORMAL POOL
POND VOLUME
Contour Incremental Cumulative
Elevation Area Volume Volume
(FT) (SF) (CF) (CF)
Bottom Elevation
31 9864 0 0
32 11435 10649.5 10650
33 13078 12256.5 22906
34 14783 13930.5 36837
Normal Pool Elev. 35 16550 15666.5 52503
36 37504 27027 79530
37 40712 39108 118638
38 43978 42345 160983
39 47300 45639 206622
FOREBAY VOLUME
Contour Incremental Cumulative
Elevation Area Volume Volume
(FT) (SF) (CF) (CF)
Bottom Elevation
31 10480 0 0
32 11949 11215 11215
33 13496 12723 23937
Top Elevation 34 15091 14294 38231
35 16740 15916 54146
FOREBAY VOLUME MUST REPRESENT 20 % OF TOTAL NORMAL POOL VOLUME.
FOREBAY VOLUME REQUIRED (WITHIN +/- 2%) = 0.2 x (POND VOL. + FOREBAY VOL.)
= 46938 TO 57369 CF
FOREBAY VOLUME PROVIDED = CF
FOREBAY VOLUME REPRESENTS 20.8% OF NORMAL POOL VOLUME
a.

' POND "2"
NCDENR DWQ STORMWATER MANAGEMENT CALCULATIONS
' Project Name: Lowes of Greenville, NC
Project No.:
Date: 3/1/2007
BASIN INFORMATION
TOTAL AREA DRAINING TO POND (DA)= 286,625 SF = 6.58 AC
IMPERVIOUS SURFACES DRAINING TO POND = 183,388 SF 4.21 AC
DRAINAGE AREA PERCENT IMPERVIOUS (%IMP) = 64.0%
NORMAL POOL SURFACE AREA REQUIREMENTS
(Based on 85 % TSS Removal Chart, No Vegetated Filter)
' POND DEPTH = 3 FT
SA/DA % = 2.6 (FROM Table 1.1, DENR)
' SURFACE AREA REQUIRED = 7,452 SF
SURFACE AREA PROVIDED = 12,197 SF @ ELEVATION 39
Therefore, Normal Pool surface area is ADEQUATE
~-~

1
1
1
1
1
1
1
1
1
1
POND "2"
POND AND FOREBAY VOLUMES BELOW NORMAL POOL
POND VOLUME
Contour Incremental Cumulative
Elevation Area Volume Volume
(FT) (SF) (CF) (CF)
Bottom Elevation
39 4364 0 0
40 5365 4865 4865
41 6565 5965 10830
42 7789 7177 18007
Normal Pool Elev. 43 22057 14923 32930
44 24157 23107 56037
45 26315 25236 81273
46 28529 27422 108695
FOREBAY VOLUME
Contour Incremental Cumulative
Elevation Area Volume Volume
(FT) (SF) (CF) (CF)
Bottom Elevation
39 7833 0 0
40 8931 8382 8382
41 10091 9511 17893
Normal Pool Elev. 42 11312 10702 28595
FOREBAY VOLUME MUST REPRESENT 20% OF TOTAL NORMAL POOL VOLUME.
FOREBAY VOLUME REQUIRED (WITHIN +/- 2%) = 0.2 x (POND VOL. + FOREBAY VOL.)
= 24712 TO 30204 CF
FOREBAY VOLUME PROVIDED = 28595 CF
FOREBAY VOLUME REPRESENTS 20.8% OF NORMAL POOL VOLUME
C~

~. ~er~ral
~~ ~ sib >xse~~ saw a stmt e~e~fiti-ng. ~gtis tca ~~eicib
s~cl1~ "~ ~ €€c gre~~r: ~$arfi~tY, ~ ~„ Ig'Sl, gp- 4~fi-~29; ~larirla IMP, l~3$2,
~~. Er2$9,).
b. ~ tta; taasia~ ~ ~ ~ ~rii€~er+t p +daui€~ c+ons~rueti~t. all sediment ~eposnte~i ciuriisg
ctg~~tztf ~ be.€e~t~~f ~~~ ~~ heg,~.
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1
APPENDIX D
FIRST FLUSH AND DEWATERING TIME
CALCULATIONS
1
1

LAND
~ PLANNING
~ ASSOCIATES, INC.
' CALCULATION SHEET PAGE 1 OF 2
PROJECT NO. 6.035

'
CLIENT: Lowes Home Stores SUBJECT: SWM Report _
Prepared By SSP Date 3/5/07
PROJECT: Lowes of Greenville NC Dewatering Time Calculations Reviewed By PMR Date 3/5/07
Greenville, North Carolina
' TASK: Determine dewatering time for the temporary pool (1 inch storm event) during a 10-year storm.
' CALCULATIONS:
POND 1
' Based on the size of the pond, the one inch storm event is stored at elevation 32.4. Using Hydraflow Hydrographs, it is
determined that this volume is achieved after 11.5 hours. The orifice being used to release this runoff is one 2" orifice at 31.0.
' Therefore, for the first 1.4 feet of volume (the temporary pool), the dewatering time is as follows:
Q = (0.6)(A)(2gh)uz
' H = 32.4- 31.0 = 1.4 ft to 2" orifice
A = 2" orifice = 0.021 sf
Q=(0.6)(0.021)[(2)(32.2)(1.4)]12
Q=0.1196cfs
The volume of the temporary pool is 31,332 cf.
To release this volume it will take how many hours (H):
' 31,332 cf / H * (1 hr / 60 min) * (1 min / 60 sec) = 0.1196 cfs
31,332 cf = 430.5(H)
H = 72.78 hours
Total dewatering time:
11.5 + 72.78 = 84.28 hours
Tota/dewatering time: 84 hours
Conclusion: 10-year storm will dewater in less than a 4 day period.

LAND
' ~ PLANNING
- ASSOCIATES, INC.
CALCULATION SHEET PAGE 2 OF 2
PROJECT NO. 6.035_
' CLIENT: Lowes Home Stores SUBJECT: SWM Report Prepared By SSP Date 3/5/07
PROJECT: Lowes of Greenville NC Dewaterin~ Time Calculations Reviewed By PMR Date 3/5/07
Greenville, North Carolina
POND 2
' Based on the size of the pond, the one inch storm event is stored at elevation 40.1. Using Hydraflow Hydrographs, it is
determined that this volume is achieved after 11.6 hours. The orifice being used to release this runoff is one 2" orifice at 39.0.
' Therefore, for the first 1.1 feet of volume (the temporary pool), the dewatering time is as follows:
Q = (0.6)(A)(2gh)~~z
' H = 40.1- 39.0 = 1.1 ft to 2" orifice
A = 2" orifice = 0.021 sf
' Q =(0.6)(0.021)[(2)(32.2)(1.1)]'2
Q=0.106cfs
The volume of the temporary pool is 14,948 cf.
To release this volume it will take how many hours (H):
14,948 cf / H * (1 hr / 60 min) * (1 min / 60 sec) = 0.106 cfs
14,948 cf = 381.7(H)
H = 39.16 hours
Total dewatering time:
11.6 + 39.16 = 50.76 hours
Total dewatering time: 51 hours
Conclusion: 10-year storm will dewater in just over a 2 day period.
Z

POND "1"
NCDENR DWQ WET DETENTION BASIN CALCULATIONS
Project Name: Lowes of Greenville, NC
Project No.:
Date: 3/5/2007
BASIN INFORMATION
TOTAL AREA DRAINING TO POND (DA)= 478,724 SF = 10.99 AC
IMPERVIOUS SURFACES DRAINING TO POND = 391,169 SF 8.98 AC
DRAINAGE AREA PERCENT IMPERVIOUS (%IMP) = 81.7%
Volume to be Controlled from 1" storm
Rv = 0.05 + 0.009(1)
Rv =runoff coefficient -storm runoff (inches) /storm rainfall (inches) = 81.71
I -Percent Impervious =Drainage area (acres) /Impervious protion of drainage area (acres)
Rv = 0.785
For the volume that must be controlled:
Volume = (design Rainfall)(Rv)(Drainage Area)
Volume = 1" rainfall * Rv * 1/12 (ft/inch) * Drainage Area
Volume = 0.72 ac-ft
or 31,332.35 cf
Page ~ .3
1

1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
Hydrograph Plot
Hydraflow Hydrographs by Intelisolve
Hyd. No. 3
Post Area 1 Thru Pond
Hydrograph type =Reservoir
Storm frequency = 10 yrs
Inflow hyd. No. = 2
Max. Elevation = 35.68 ft
Peak discharge = 3.41 cfs
Time interval = 1 min
Reservoir name =Pond
Max. Storage = 2.998 acft
Storage Indication method used.
Hydrograph Volume = 1.759 acft
3 -Reservoir -10 Yr - Max. EI. = 35.68 ft
36
35 -
34
...
m
w 33
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32
31
0.00 2.40 4.80 7.20 9.61 2.01 14.41 16.81 19.2121.6124.02
Time ( rs)
~~~5~
~~
n

POND "2"
NCDENR DWQ WET DETENTION BASIN CALCULATIONS
Project Name: Lowes of Greenville, NC
Project No.:
Date: 3/5/2007
BASIN INFORMATION
TOTAL AREA DRAINING TO POND (DA)= 286,625 SF = 6.58 AC
IMPERVIOUS SURFACES DRAINING TO POND = 183,388 SF 4.21 AC
DRAINAGE AREA PERCENT IMPERVIOUS (%IMP) = 64.0%
Volume to be Controlled from 1"storm
Rv = 0.05 + 0.009(1)
Rv =runoff coefficient -storm runoff (inches) /storm rainfall (inches) = 63.98
I -Percent Impervious =Drainage area (acres) /Impervious protion of drainage area (acres)
Rv = 0.626
For the volume that must be controlled:
Volume = (design Rainfall)(Rv)(Drainage Area)
Volume = 1" rainfall * Rv * 1/12 (ft/inch) * Drainage Area
Volume = 0.34 ac-ft
or 14,948.34 cf
Page fl

Hydrograph Plot
Hydraflow Hydrographs by Intelisolve
Hyd. No. 6
Area 2 to Pond 2
Hydrograph type =Reservoir
Storm frequency = 10 yrs
Inflow hyd. No. = 5
Max. Elevation = 42.94 ft
Peak discharge = 2.41 cfs
Time interval = 1 min
Reservoir name = Pond2
Max. Storage = 1.515 acft
Storage Indication method used.
a~
w
Hydrograph Volume = 1.114 acft
)2
Time (hrs)
~~.(O ~
b-C~
6 -Reservoir -10 Yr -Max. EI. = 42.94 ft

APPENDIX E
HYDRAFLOW STORM DRAIN PIPE
CALCULATIONS

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Hydraflow Storm Sewers 2003

Storm Sewer Summary Report
Page 1
Line Line ID Flow Line Line Invert Invert Line HGL HGL Minor Dns
No. rate size length EL Dn EL Up slope down up loss line
(cfs) (in) (ft) (ft) (ft) (%) (ft) (ft) (ft) No.
1 1 to 2 58.96 48 c 39.0 36.00 37.56 4.000 38.37 39.83 1.49 End
2 2 to 3 33.77 36 c 86.0 41.00 41.86 1.000 42.85 43.71 0.59 1
3 3 to 4 33.90 36 c 100.0 41.96 42.46 0.500 44.30 44.45 0.36 2
4 4 to 5 32.16 36 c 54.0 42.56 42.83 0.500 44.81 44.86 0.93 3
5 5 to 6 30.35 36 c 68.0 42.93 43.61 1.000 45.79 45.75 0.74 4
6 5 to 7 18.84 30 c 223.0 42.93 45.16 1.000 46.49 46.88 0.21 5
7 7 to 8 15.94 24 c 137.0 45.26 46.63 1.000 47.09 48.04 0.88 6
8 8 to 9 11.52 24 c 72.0 46.73 47.45 1.000 48.92 49.03 0.15 7
9 9 to 10 5.84 18 c 131.0 47.55 48.86 1.000 49.18 49.78 0.41 8
10 5 to 12 2.09 18 c 126.0 45.50 46.76 1.000 46.05 47.31 0.19 4
11 6 to 13 7.68 30 c 74.0 43.71 44.45 1.000 46.49 46.50 0.02 5
12 13 to 14 5.46 24 c 34.0 44.55 44.89 1.000 46.53 46.53 0.08 11
13 14 to 15 2.01 18 c 39.0 44.99 45.38 1.000 46.61 46.62 0.03 12
14 2 to 16 25.84 24 c 70.0 44.00 44.70 1.000 45.79* 46.78* 0.53 1
15 16 to 17 21.13 24 c 80.0 44.80 45.60 1.000 47.31 * 48.00* 0.35 14
16 17 to 18 16.16 24 c 80.0 45.70 46.50 1.000 48.36* 48.76* 0.21 15
17 18 to 19 11.35 24 c 80.0 46.60 47.40 1.000 48.97 49.13 0.17 16
18 19 to 20 7.12 18 c 70.0 47.50 48.20 1.000 49.30 49.58 0.27 17
Project File: GNC1.stm Number of lines: 18 Run Date: 03-04-2007
NOTES: c =circular; a =elliptical; b =box; Return period = 10 Yrs.; * Indicates surcharge condition.
3 Hydraflow Storm Sewers 2003

~~ w r~ w w ^r w w r~~ w r r w w w
Storm Sewer Tabulation Page ,
m
Station Len Drng Area Rnoff Area x C Tc Rain Total Cap Vel Pipe Invert Elev HGL Elev Grnd /Rim Elev Line ID
coeff (I) flow full
Line To Incr Total Incr Total Inlet Syst Size Slope Up Dn Up Dn Up Dn
Line
(ft) (ac) (ac) (C) (min) (min) (in/hr) (cfs) (cfs) (ft/s) (in) (%) (ft) (ft) (ft) (ft) (ft) (ft)
1 End 39.0 0.39 9.85 0.90 0.35 8.66 5.0 8.6 6.8 58.96 287.3 7.80 48 4.00 37.56 36.00 39.83 38.37 54.60 40.00 1 to 2
2 1 86.0 0.06 5.67 0.90 0.05 4.89 5.0 8.3 6.9 33.77 66.69 7.37 36 1.00 41.86 41.00 43.71 42.85 54.75 54.60 2 to 3
3 2 100.0 0.32 5.61 0.90 0.29 4.84 5.0 7.9 7.0 33.90 47.16 6.28 36 0.50 42.46 41.96 44.45 44.30 54.20 54.75 3 to 4
4 3 54.0 0.05 5.29 0.90 0.05 4.55 5.0 7.7 7.1 32.16 47.16 5.99 36 0.50 42.83 42.56 44.86 44.81 53.50 54.20 4 to 5
5 4 68.0 0.80 4.95 0.90 0.72 4.25 5.0 7.5 7.1 30.35 66.69 4.99 36 1.00 43.61 42.93 45.75 45.79 51.20 53.50 5 to 6
6 5 223.0 0.48 2.94 0.90 0.43 2.52 5.0 6.4 7.5 18.84 41.01 4.53 30 1.00 45.16 42.93 46.88 46.49 53.80 51.20 5 to 7
7 6 137.0 0.71 2.46 0.85 0.60 2.09 5.0 6.0 7.6 15.94 22.62 6.00 24 1.00 46.63 45.26 48.04 47.09 54.00 53.80 7 to 8
8 7 72.0 0.89 1.75 0.85 0.76 1.49 5.0 5.7 7.7 11.52 22.62 4.00 24 1.00 47.45 46.73 49.03 48.92 53.50 54.00 8 to 9
9 8 131.0 0.86 0.86 0.85 0.73 0.73 5.0 5.0 8.0 5.84 10.50 4.22 18 1.00 48.86 47.55 49.78 49.18 53.50 53.50 9 to 10
10 4 126.0 0.29 0.29 0.90 0.26 0.26 5.0 5.0 8.0 2.09 10.50 3.54 18 1.00 46.76 45.50 47.31 46.05 50.50 53.50 5 to 12
11 5 74.0 0.43 1.21 0.70 0.30 1.00 5.0 5.9 7.7 7.68 41.01 1.67 30 1.00 44.45 43.71 46.50 46.49 49.80 51.20 6 to 13
12 11 34.0 0.50 0.78 0.90 0.45 0.70 5.0 5.6 7.8 5.46 22.62 1.86 24 1.00 44.89 44.55 46.53 46.53 48.80 49.80 13 to 14
13 12 39.0 0.28 0.28 0.90 0.25 0.25 5.0 5.0 8.0 2.01 10.50 1.22 18 1.00 45.38 44.99 46.62 46.61 48.80 48.80 14 to 15
14 1 70.0 0.72 3.79 0.90 0.65 3.41 5.0 6.1 7.6 25.84 22.62 8.48 24 1.00 44.70 44.00 46.78 45.79 54.60 54.60 2 to 16
15 14 80.0 0.75 3.07 0.90 0.68 2.76 5.0 5.9 7.6 21.13 22.62 6.73 24 1.00 45.60 44.80 48.00 47.31 54.60 54.60 16 to 17
16 15 80.0 0.72 2.32 0.90 0.65 2.09 5.0 5.7 7.7 16.16 22.62 5.15 24 1.00 46.50 45.70 48.76 48.36 54.60 54.60 17 to 18
17 16 80.0 0.61 1.60 0.90 0.55 1.44 5.0 5.3 7.9 11.35 22.62 3.77 24 1.00 47.40 46.60 49.13 48.97 54.60 54.60 18 to 19
18 17 70.0 0.99 0.99 0.90 0.89 0.89 5.0 5.0 8.0 7.12 10.50 4.11 18 1.00 48.20 47.50 49.58 49.30 54.60 54.60 19 to 20
Project File: GNC1.stm Number of lines: 18 Run Date: 03-04-2007
NOTES: Intensity =54.93 / (Inlet time + 9.60) ^ 0.72; Return period = 10 Yrs.
Hydraflow Storm Sewers 2003

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Project file: GNC22.stm No. Lines: 9 03-02-2007
Hydraflow Storm Sewers 2003

Storm Sewer Summary Report
Page 1
Line Line ID Flow Line Line Invert Invert Line HGL HGL Minor Dns
No. rate size length EL Dn EL Up slope down up loss line
(cfs) (in) (ft) (ft) (ft) (%) (ft) (ft) (ft) No.
1 22 TO 23 21.39 30 c 44.0 40.00 40.88 2.000 41.55 42.43 1.05 End
2 23 TO 24 19.72 24 c 215.0 43.37 44.45 0.502 44.94* 46.89* 0.92 1
3 24 TO 26 3.02 18 c 119.0 44.55 44.85 0.252 47.81 * 47.91 * 0.07 2
4 26 TO 27 1.37 15 c 34.0 44.95 45.12 0.500 47.98* 47.99* 0.02 3
5 24 TO 25 11.92 18 c 183.0 46.00 47.83 1.000 47.81 * 50.17* 0.35 2
6 25 to 11 5.97 18 c 131.0 47.93 49.24 1.000 50.53* 50.95* 0.18 5
7 23 TO 28 2.53 15 c 123.0 46.00 47.23 1.000 46.64 47.87 0.13 1
8 28 TO 29 1.67 15 c 126.0 47.33 48.59 1.000 47.99 49.11 0.09 7
9 29 to 21 1.37 15 c 50.0 48.69 49.19 1.000 49.20 49.66 0.17 8
Project File: GNC22.stm Number of lines: 9 Run Date: 03-02-2007
NOTES: c =circular; a =elliptical; b =box; Return period = 10 Yrs.; * Indicates surcharge condition.
-~ f n HydraFlow Storm Sewers 2003

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Storm Sewer Summary Report
Page 1
Line Line ID Flow Line Line Invert Invert Line HGL HGL Minor Dns
No. rate size length EL Dn EL Up slope down up loss line
(cfs) (in) (ft) (ft) (ft) (%) (ft) (ft) (ft) No.
1 39 TO 38 10.76 24 c 79.0 40.00 40.79 1.000 41.16 41.95 0.63 End
2 38 TO 37 10.17 24 c 20.0 40.89 41.09 1.000 42.58 42.56 0.26 1
Project File: GNC39.stm Number of lines: 2 Run Date: 03-02-2007
NOTES: c =circular; a =elliptical; b =box; Return period = 10 Yrs.; * Indicates surcharge condition.
`! ~, ~ J"'1 Hydraflow Storm Sewers 2003

APPENDIX F
SEDIMENT AND EROSION CONTROL
CALCULATIONS

1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
Sediment and Erosion Control Calculations
The construction of this project will take place in several phases. The first phase will
allow the building pad area to be established and four sediment traps will be provided on
site. The second phase will begin the storm drain and utility installation and the
construction of the detention basins to be used on site, therefore one trap and two
sediment basins will be provided. Phase 3 is the completion of the paving, sidewalk and
landscaping and the use of the permanent detention ponds.
Phase 1
Four sediment traps are proposed for Phase 1 of construction. Each trap has been
designed for a maximum of 5 on-site acres.
Area Draining to Sediment Trap : 5 acres
Per DENR Requirements:
Volume Required is 3600 cf /acre
3600 * (5) = 18,000 cf
Per Hydraflow,
Q10 for the post-developed flow for 5 acres (CN: 80, Tc=10 min) is: 30 cfs
Surface Area Required: 0.01 * Q
0.01 *30 = 0.30 ac ft. = 13,068 sf
Spillway to carry 10 year storm, therefore spillway to be sized using weir equation:
Q = 3.27 * (L) * (H) 3ia
30 = 3.27 * (L) * (1)312
L = 9.17 feet (use 9 feet)
Basin to be clean out at %2 required storage, therefore cleanout is required at 6,534 cubic
feet.
The trap designed is as follows:
Elevation Area (sf) Volume (cf)
Spillway + 2 (top) 15,400 61,748
spillway + 1 14,434 39,131
spillway 13,493 25,168
spillway - 1 12,578 12,133
bottom 11,688 0
Required Volume provided at elevation 0.5 feet BELOW spillway elevation
Required Surface area provided at elevation spillway elelvation.
cleanout elevation to be marked at 0.5 feet above bottom of trap.
Top of trap is 2 feet above spillway elelvation, therefore 1 foot of freeboard is provided.
~~

Phase 2
During Phase 2, the sediment trap located in the southwest corner of the property (closest
to the proposed truckwell area for the building) will remain in place. The remainder of
the property will be directed to one of two sediment basins located in the same place as
' the proposed detention pond for the property.
Sediment Basin 1
' Area Draining to Sediment Basin : 9 acres. Per Hydraflow, Q10 for the post-developed
flow for 9 acres (CN: 80, Tc = 10 min) is: 54 cfs
Per DENR Requirements:
Volume Required is 3600 cf /acre
3600 * (9) = 32,400 cf
Surface Area required: 0.01 * Q
0.01 * 54 = 0.54 ac ft. = 23,522 sf
Spillway to carry 10 year storm, therefore spillway to be sized using weir equation:
Q = 3.27 * (L) * (H) sit
54 = 3.27 * (L) * (1)312
L = 16.5 feet (use 17 feet)
Basin to be clean out at %2 required storage; therefore cleanout is required at 16,200 cubic
feet.
Using portion of permanent detention pond for sediment basin, volume and area provided
is as follows:
Elevation Area (sf) Volume (cf)
34 19348 0
35 22023 20,685
36 24755 44,074
37 27543 70,223
38 30388 99,188
Required Volume provided at elevation 35.5 feet.
1 Required surface area provided at elevation 35.54.
Place spillway at elevation 36 and top of basin at 38.
cleanout elevation is at 34.78.
To drain the sediment basin a Faircloth Skimmer has bee specified. A 4" Skimmer
should be used so that the volume of runoff below the emergency spillway will be
released in just over a 2-day period. See attached Skimmer information in this Appendix.
~- ~

Sediment Basin 2
Area Draining to Sediment Basin :5.17 acres. Per Hydraflow, Q10 for the post-
developed flow for 5.17 acres (CN: 80, Tc = 10 min) is: 31 cfs

Per DENR Requirements:
Volume Required is 3600 cf /acre
3600 * (5.17) = 18,612 cf
Surface Area required: 0.01 * Q
' 0.01 * 31 = 0.31 ac ft. = 13,503 sf
Spillway to carry 10 year storm, therefore spillway to be sized using weir equation:
I Q = 3.27 * (L) * (H) 3n
3iz
31 = 3.27 * (L) * (1)

1 L = 9.48 feet (use 10 feet)
Basin to be clean out at %2 re uired stora e• therefore cleanout is re uired at 9 306 cubic
q g~ q
' feet.
Using portion of permanent detention pond for sediment basin, volume and area provided
1 is as follows:
Elevation Area (sfj Volume (cf)
41 11,260 0
I 42 12,830 12,045
43 14,767 25,843
44 16,568 41,510
45 18,426 59,077
' Required Volume provided at elevation 42.47 feet.
Required surface area provided at elevation 42.5.
Place spillway at elevation 43 and top of basin at 45.
' Cleanout elevation is at 41.77.
To drain the sediment basin a Faircloth Skimmer has bee specified. A 4" Skimmer
1 should be used so that the volume of runoff below the emergency spillway will be
released in just under a 2-day period. See attached Skimmer information in this
Appendix.

t
1
~3
t

' Phase 3
During Phase 3 the final site preparations will be completed and the storm drain pipe and
' inlets will all be installed. Inlet protection will be at each inlet, stone base will be down
on all proposed paving areas. Building construction will be almost complete. Sediment
Basins from Phase 2 will be enlarged to meet the proposed permanent pond design.
' Additional measures should not be required.
~., y

4" Faircloth Skimmer Cut Sheet
J. W. Faircloth & Son, Inc.
www. FairclothSkimmer.com
' ~ef`{9~R`YO
~~~g ~
~~r~fl~~4~bn
2"Vent
with Orange tip
Inlets Aluminum straps
suspending inlet
~_:
33„ 2
~-
~. ~ \`.~: k \...
~~
4" pvc float
3" Sch 40 SOLID pvc barrel
or"arm"
SUPPLIED BY USER s
3" hose, ss clamps
3" threaded male nipple
on outlet end
Patent ~: 5,820,751
Skimmer shown in
floating position
4" inlet 3.3" HEAD on center
extension a of inlet and orifice
1. Coupling can be removed and hose attached to outlet using the threaded 3" nipple. Typical
methods used: on a metal structure a steel stubout welded on the side at the bottom with a 3"
threaded coupling or reducers; on a concrete structure with a hole or orifice at the bottom, use a
steel plate with a hole cut in it and coupling welded to it that will fit over the hole in the concrete
and bolted to the structure with sealant. It is possible to grout a 4" pvc pipe in a hole in the
concrete to connect the skimmer but this is less secure than other methods.
2. Dimensions are approximate, not intended as plans for construction.
3. Barrel (solid, not foam core pipe) should be 1.4 times the depth of water with a minimum
length of 8' so the inlet can be pulled to the side for maintenance. If more than 10' long weight
may have to be added to inlet to counter the increased buoyancy.
4. Inlet tapers down from 4" maximum inlet to a 3" barrel and hose. Barrel is smaller to reduce
buoyancy and tendency to lift inlet but is sufficient for flow through inlet because of slope. The
inlet orifice can be reduced using the plug and cutter provided to control the outflow rate.
5. Inlet is 8" pipe between the straps with slots cut in the inlet and aluminum screen door
(smaller than shown in illustration) for access to the 4" inlet and orifice inside.
6. Capacity 18,267 cubic feet per day maximum with 4" inlet and 3.3" head. Inlet can be
reduced by installing a smaller orifice using the plug and cutter provided to adjust flow rate for
the particular basin volume and drawdown time required.
7. Shipped assembled. User glues inlet extension and barrel, installs vent, cuts orifice in plug
and attaches to outlet pipe or structure. Includes flexible hose, rope, orifice cutter, etc.
4inchCut January 26, 2007
~- S

4" Faircloth Skimmer
' Instructions for Assembly, Use and Maintenance
You Will Need:
' 8 feet or more of 3" Sch 40 PVC pipe SOLID
Primer and glue for PVC pipe
Phillips screw driver, maybe a knife
' Assembly and Installation Directions.
1. Glue on the 4" inlet extension to the Tee on the inlet. Install the vent.
Details Prime and glue the 4"inlet extension (with the coupling, 3"bushing and screws on one end) into the 4"
end of the Tee on the side of the Inlet (8"horizontal tube suspended between the sides of the float with the
aluminum screen door).
Install the vent into the socket in the Tee, back the screw out, insert the short end of the vent, point the long end
toward the door on the inlet, and tighten the screw. Use a little grease so it can be removed later.
Rope
4" Sch 40
coupling 3" Sch 40 SOLID pvc
connection barrel or "arm"
SUPPLIED BY USER
3" hose
l,'> ~~
4" inlet
'~
- extension
`:~
Vent --
__
~~
r
Palenl ~: 5,820,751
Inlet
Door Smaller
Than Shown
Skimmer shown in
floating position
' 2. Glue the 8' long 3" sch 40 barrel to the 3" grey coupling on the hose.
Details You will need 3"Sch 40 PVC pipe (solid, not foam core) for the barrel (or "arm') between the float
1 assembly and the 3"hose. The length of the pipe should be about 1.4 times the depth of the basin so the
skimmer floats properly when the basin fills with a minimum length of 8'so the skimmer can be pulled to the side
of the basin for maintenance.
3. Put the other end of the barrel into the socket on the inlet extension and tighten the screws.
Details Make sure the screw points are not protruding into the 3"bushing on the outlet end of the inlet extension
you glued onto the Tee.
WITHOUT GLUE OR PRIMER, but with a little grease, insert the other end of the pipe into the bushing all the way
in until it hits bottom. It may be easier to do this in the basin after you have connected the hose to the pipe, riser or
outlet structure. Tighten the screw so the point enters the pipe to secure it; it does not have to go all the way in.
' This connection is not glued to allow disassembly and possible reuse of the skimmer later.
If barrel is longer than 10 ; weight may have to be added to the inlet so it sits at the right depth.
4. Cut the orifice in the plug (size shown on the erosion control plans), put the plug in the inlet, and tighten the
screw. Close the door.
June 7, 2006 1 4" Skimmer
(~~ ~D

Details Refer to the erosion control plans for the orifice size.
plug in the inlet. Follow the instructions below for cutting the
ORIFICE. Install the orifice in the inlet, secure it with the screw
(through the hole in the top of the inlet) and close the door and
secure if with the screw eye. If you do not know the size of the
orifice, refer to the instructions on the next page.
5. Cut a trench in the bottom of the basin 1' to 2' deep under where
the skimmer will be placed. If required, place a support under the
skimmer inlet.
Details If the skimmer will settle to the bottom when the basin
drains it is recommended that a 1' - 2' deep trench a backhoe
bucket wide should be excavated under the skimmer to catch
sediment that will settle under the skimmer.
the door on the inlet and remove the 4"
If a pool of water is to be provided, install the support under the skimmer inlet as shown on the erosion control
plans. !t is recommended that the hose connection to the pipe through the dam be low enough that the whole pond
can be drained using the skimmer even if a pool of water is to be provided. Doing this will avoid using a pump fo
drain the very bottom of the pond.
If ice is expected during winter place the skimmer near the dam or side of the basin where the ice will be the
thinnest and you can get to the inlet to break the ice and keep water flowing through the skimmer. But do not put it
so close to the side that the skimmer cannot settle to the bottom and drain the whole basin.
6. Attach the 4" coupling on the hose to the outlet structure.
Details Make sure the screw points are not protruding into the 4"coupling on the hose and attach it to the
plastic pipe sticking out from the structure. Tighten the screws just so the points go into the plastic to secure it.
Greasing the pipe is recommended so the hose can be removed later.
If the connection pipe is larger than 4"you will need a coupling for that pipe, a bushing for that coupling with a 4"
socket, and about 10" of 4"pipe to create an attachment.
If attaching to a metal pipe you will need a rubber coupling (Fernco) and a short piece of 4" pvc pipe to make the
connection.
OR The 4"coupling can be removed and the hose connected using the 3"threaded fitting. If attaching to a
concrete structure with a hole or orifice at the bottom, either: 7) grout a 4"PVC pipe into the hole and connect the
hose: or 2) a more secure way, the recommended method, is to use a steel plate with a hole cut in it and 3"
coupling welded to it that will fit over the hole in the concrete and bolt the plate to the structure with sealant to
make it water tight.
7. Attach the rope to the Tee and the other end to a stake on the side of the basin.
Details Tie one end of the rope around the Tee between the vent socket and the 8" tube on the inlet. Secure the
other end to a stake or post on the dam or side of the basin where it can be used to pull the skimmer to the side if
necessary to remove trash and debris.
8. Put a fence post, 1 not 2, on the opposite side of the barrel from where the rope is tied to a stake to keep the
skimmer in place.
Details Put the skimmer where you want it to settle to the bottom and drive a metal fence post into the ground on
' the outside of the barrel (away from the side) 2' from the float to hold the skimmer in that place. Make sure it is
high enough so the barrel does not float over the top when the basin fills. Posts on both sides of the barrel are not
recommended because it will prevent pulling the skimmer to the side for maintenance.
9. Take a break.
June 7, 2006 2 4" Skimmer
r _~

Maintenance
Trash: If the inlet screen clogs and there is water in the basin, tugging on the rope several times will usually wash
the trash off and restore flow. If not, pull the inlet to the side of the basin and use a stick to clean the screen. Open
the screen door and remove any trash or sediment inside so grass or trees do not grow in the inlet. (Yes, this can
happen!)
Sediment Accumulation Around Skimmer: A shallow, long basin, using baffles, and inflow in the basin at the
opposite end from the outlet help keep sediment away from the skimmer. If sediment restricts skimmer movement,
pull the skimmer to one side and excavate under it.
Ice: Try to keep ice broken up at the inlet and around the barrel to keep water flowing, making it less likely the inlet
will freeze. Spray painting the float black to absorb heat is recommended. Use paint that will stick to PVC plastic.
Handling the Skimmer: The skimmer is made of plastic and will withstand heat, cold and sunlight but it needs to
be handled by hand, NOT grabbed with a backhoe bucket and yanked around, especially in cold weather. To
remove the skimmer, disconnect the hose first, then disconnect the barrel from the inlet extension. DO NOT try to
pull the skimmer loose with a backhoe.
Vandalism: Keep unauthorized persons that may do damage off the site. Do not provide rocks close to the
skimmer if possible. If possible, taking other considerations into account, position the skimmer out in the basin
away from the banks to decrease the potential for a successful hit.
Call if you have problems or questions
Cutting and Installing the ORIFICE in the Inlet
Purpose: cutting a smaller hole or orifice (less than 4") in the plug and installing it in the inlet reduces the flow rate
through the skimmer to match the volume of the basin and the number days to drain the basin. It customizes the
skimmer for the basin it is used in and is not optional if the erosion control plan calls for a specific orifice.
1. The size of the orifice should be shown on the erosion control plans with the sediment basin specifications. If so
use the following instructions to adjust the cutter, cut the orifice in the plug, and put the plug in the inlet. If the size
is not shown use the instructions on the next page to determine the orifice size or call us.
2. Cutting the Orifice After finding the size of the orifice on the plans or determining the size use the cutter provided
to cut the hole in the center of the plastic plug you removed from the inlet.
Measure the radius (1/2 of the diameter) of the required orifice from the center of the pilot hole in the plug and
mark it with a pencil.
0
2
Fold Page on Bottom Line to Create Ruler for Measuring Orifice Radius
4
6
BE CAREFUL OF THE SHARP NAIL POINT! Loosen the bolt in the slot by turning the wing nut. Place the end of
the bolt with the 2 nuts on it in the pilot hole in the center of the plastic plug. Place the point of the nail on the mark
for the orifice radius.
While holding the bolt at the proper place, remove the cutter from the pilot hole and tighten the wing nut. You
should be able to tighten it without a wrench or pliers.
Next, insert the end of the bolt back in the pilot hole in the plastic plug so the nail point is against the plug. Hold the
plug in one hand while turning the cutter with the other hand and scour the plug. Don't try to cut through the plug
with just one turn, take several on each side. Turn the plug over and scour the other side several times.
The center of the hole should pop out after scouring both sides even if the plastic is not cut completely through
around the entire perimeter. If not, CAREFULLY use a knife and cut around the scour line to finish cutting through.
3. Installing the Orifice Remove the screw eye holding the aluminum screen door on the inlet and open the door to
get to the inlet:
' June 7, 2006
4" Skimmer
~s

Put the plug into the inlet, the 4" pipe sticking through the side of the 8" pipe with the Tee attached to it. See the
picture above. Tighten the screw on the inlet enough so the point goes into the plug. Put the Phillips screwdriver
' through the hole in the top of the inlet to reach this screw. Check to make sure the plug is secure.
DON'T GLUE THE PLUG IN THE INLET. Doing so limits reusing the skimmer on another sediment basin that
' requires a different size orifice.
Close the door and replace the screw eye to hold it shut.
Determining Orifice Size
Draining the sediment basin in the required time involves: #1 choosing the size skimmer needed to drain the basin's
volume in the specified number of days, in this case a 4" skimmer; and #2 adjusting the flow rate through the skimmer
using a smaller orifice or hole placed in the inlet pipe. To determine the radius of this orifice divide the basin's volume
by a factor (from #2 below) for the number of days to drain the basin; the result is the required area of the orifice.
Then, calculate the orifice radius using Area = ~ rz and solving for r, r = (Area / 3.14) .The cutter can be adjusted
to that radius and the orifice cut in the plastic plug that fits in the inlet as described above. This procedure
"customizes" the skimmer for the basin it will be installed in.
' 1. Approximate skimmer maximum capacities based on typical draw down requirements, which can vary between
States and jurisdictions and watersheds. Draining the basin in less than 2 days is not recommended.
4" skimmer 18,267 cubic feet in 24 hours 91,335 cubic feet in 5 days
with a 3.3" head 36,534 cubic feet in 2 days 109,602 cubic feet in 6 days
54,803 cubic feet in 3 days 127,869 cubic feet in 7 days
72,000 cubic feet in 4 days
' 2. Factors (in cubic feet of flow per square inch of opening through a round orifice for the draw down times shown) to
use in determining the orifice radius in inches for a particular basin volume to be drained. This quick method works
because the orifice is centered and has a constant head, (the distance between the center and the water surface).
An alternative method is to use the orifice equation (C = 0.59) with the head for the particular skimmer (shown
under #1 above) and determine the required orifice for the volume and draw down time.
4" skimmer 1,454 to drain the basin in 24 hours 7,270 to drain the basin in 5 days
2,908 to drain the basin in 2 days 8,724 to drain the basin in 6 days
4,362 to drain the basin in 3 days 10,178 to drain the basin in 7 days
5,816 to drain the basin in 4 days
The 1) size skimmer necessary for the sediment basin and 2) the required orifice radius and diameter for the
skimmer should be shown on the erosion control plan for each basin. Also give the basin volume and number of
days to drain; this can be helpful when the contractor orders the skimmer. During the skimmer installation the
required orifice can be cut in the plastic plug by the contractor using the supplied cutter and installed in the
skimmer using the instructions with the skimmer.
' The plan review and enforcement authority may require calculations showing that the skimmer used can drain the
basin in the required time.
For more information on sizing the orifice and for an example problem go to our web site or call us.
Revised 2-2-01; 3-3-05; 6-7-06
J. W. Faircloth & Son Inc.
' 412-A Buttonwood Drive
PO Box 757
Hillsborough, NC 27278
' [phone]
[phone] Fax
Email: [e-mail]
fairclothskimmer.com 4inchlnstr
. June 7, 2006 4 4" Skimmer
r

Rip-Rap Calculations for Greenville, NC
Apron For Structure #1:
Flow as determined using Hydraflow Storm Sewer:
Q = 59 cfs in a 48 inch diameter pipe
Per Figure 8.06a (use minimum)
DSO = 9 inches
Dmax = 141nches
Thickness= 21 inches
Min. Length = 15 feet
Apron for Structure #22:
Flow as determined using Hydraflow Storm Sewer:
Q = 21.4 cfs in a 30" diameter pipe
Per Figure 8.06a (use minimum)
DSO = 6 inches
Dmax = 9 inches
Thickness= 14 inches
Min. Length = 8 feet
Apron for Structure #39:
Flow as determined using Hydraflow torm Sewer:
Q = 10.76 cfs from a 24 inch diameter pipe
Per Figure 8.06a (use minimum)
DSO = 6 inches
Dmax = 9 lncheS
Thickness= 14 inches
Min. Length = 8 feet
~~

Apron for Structure #34
Flow as determined using Hydraflow Hydrographs for discharge of Pond # 1 barrel pipe
during a 10-year storm event:
Q = 3.4 cfs from an 18 inch diameter pipe
Per Figure 8.06a (use minimum)
Dso = 6 inches
Dmax = 9 Inches
Thickness= 14 inches
Min. Length = 8 feet
Apron for Structure #32
Flow as determined using Hydraflow Hydrographs for discharge of Pond #2 barrel pipe
during a 10-year storm event:
Q = 2.4 cfs from an 18 inch diameter pipe
Per Figure 8.06a (use minimum)
Dso = 6 inches
Dmax = 9 Inches
Thickness= 14 inches
Min. Length = 8 feet
Apron for Structure #36
Flow as determined using Hydraflow Hydrographs for discharge of direct runoff from
off-site area during a 10-year storm event:
Q = 6.85 cfs from an 18 inch diameter pipe
Per Figure 8.06a (use minimum)
D50 = 6 inches
Dmax = 9 Inches
Thickness= 14 inches
Min. Length = 8 feet
~~

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3'~.'. a.ip~3~ t '~ t ~ t1.~~3

APPENDIX G
TOTAL NITROGEN AND TOTAL PHOSPHORUS
CALCULATIONS

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BMP Removal Calculations
' The required BMP is oversized for each drainage area. A quick way to determine removal
percentage is as follows:
1-(1-(base removal percent))"size factor
' Calculations for the Filter Strip are as follows:
Base removal Percent: TN 20
TP 35
For Pond #1
' Required Level Spreader length is 13 ft per cfs
Based on Q for 10-year storm: Q10 release from pond is 3.4 cfs
Length required: 13 x 3.4 = 44 if
Length provided: 133 if
Size factor = 3 for Pond #1
' For TN Removal
1 - (1-.20)3 = .488 or 48%
l
F
TP
remova
:
or
' 1 - (1-.35)3 = .725 or 72.5%
For Pond #2
Required Level Spreader length is 13 ft per cfs
' Based on Q for 10-year storm: Q10 release from pond is 2.4 cfs
Length required: 13 x 2.4 = 31.21f
Length provided: 321f
'
Size factor = 2 for Pond #2
' For TN Removal:
1 - (1-.20)2 = .36 or 36%
' For TP Removal:
1 - (1-.35)2 = .577 or 57.7%

1
1
1
~ ~.

1
1
1
1
1
1
Calculations for the Stormwater Wetlands are as follows:
Pond Removal Rate:
Base removal rates are as follows:
TN - 40
TP - 35
For Pond #1
Based on the required surface area, the pond is 26% larger than is required.
Surface Area Required: 16,133 sf
Surface Area Provided: 20,344 sf
20,344 / 16,133= 1.26
Therefore:
For TN Removal:
1 - (1-.40)''26 = .474 or 47.4%
For TP Removal:
1 - (1-.35)12fi = .418 or 41.8%
For Pond #2
Based on required surface area the pond is just about 1-1/2 times the required size -
1.63% to be exact.
Surface Area Required: 7,452
Surface Area Provided: 12,197
12,197 / 7,452 = 1.636
Therefore:
For TN Removal:
1 - (1-.40)1fi3 = .565 or 56.5%
For TP Removal:
1 - (1-.35)1fi3 = .504 or 50.4%
~ -3

1
1
1
1
Tar-Pamlico Stormwater Rule 15A NCAC 28.0258
Coastal Plain of the Tar-Pamlico River Basin:
Tnchules C;reenville and Washineton as well as Pitt and Beaufort Counties
Last Modified 3/4/2007
Total Nitrogen and Total Phosphorus Loading Calculation Worksheet (Automated)
Project Name: Lowe's of Greenville North Carolina
Date: 3/5/2007
By: S. Pruitt Checked By: P. Rivers
Directions (same for pre-development and post-development tables):
> Enter the acres of each type of land cover in the green boxes. The spreadsheet will calculate all of the values in light blue.
> Compare total areas of development in pre- and post- tables for consistency (bottom of column (2)), and also for consistency
with the site plans. If al] of these values are not the same, there is an error that must be corrected.
> Unless drainage onto the development from offsite is diverted around or through the site, offsite catchment area draining in m
be included in the acreage values and treated.
Pre-development:
(1) (2) (3) (4) (5) (6) (7)
Type of Land Cover Area S.M. Formula Average EMC Column Average EMC Column
(acres) (0.51 + 9.1 I) of TN (mg/L) (2) * (3) * (4) of TP (mg/L) (2) * (3) * (6)
Transportation impervious 0.55 2.60 0.00 0.19 0.00
Roof impervious 0.55 1.95 0.11 0.11 0.01
Managed pervious
0.55
1.42
0.00
0.28
0.00
(lawn/landscaped)
Managed pervious
0.55
4.23
40.62
1.23
11.81
(cropland)
Managed pervious
0.55
2.04
0.00
0.62
0.00
(pasture)
Wooded pervious 0.55 0.95 2.21 0.14 0.33
Fraction Im envious
p (I) = 0.00 TN Loadin
42.94 TP Loadin
12.14
(Ib/yr) (lb/yr)
Total Area of Development = 21.71 TN Exp. Coeff 1 98 TP Exp. Coeff 0.56
(lb/ac/yr) (Ib/ac/yr)
Post-development:
(1) (2) (3) (4) (5) (6) (7)
Type of Land Cover Area S.M. Formula Average EMC Column Average EMC Column
(acres) (0.51 + 9.1 I) of TN (mg/L) (2) * (3) * (4) of TP (mg/L) (2) * (3) * (6)
Transportation impervious 6.08 2.60 136.18 0.19 9.95
Roof impervious 6.08 1.95 55.52 0.11 3.13
Managed pervious 6.08 1.42 56.06 0.28 11.05
Wooded pervious 6.08 0.94 10.98 0.14 1.64
Fraction Impervious (I) = 0.61 TN Loadin 258 74 TP Loadin 25 77
pb/yr) (lb/yr)
Total Area of Development = 21,70 TN Exp. Coeff 11.92 TP Exp. Coeff 1.19
(lb/ac/yr) (lb/ac/yr)
Note: The nutrient loading goals are 4.0 ]b/ac/yr for TN and 0.41b/ac/yr for TP. If the post-development nutrient
loading is below these levels, then no BMP is necessary. Otherwise, the next worksheet calculates
post-development TN and TP loadings after BMPs are installed.
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Tar-Pamlico Stormwater Rule 15A NCAC 26 .0258 past nnoamea 5izsius
' Coastal Plain of the Tar-Pamlico River Basin:
Includes Greenville and Washineton as well as Pitt and Beaufort Counties
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BMP Removal Calculation Worksheet (Automated)
Project Name: Lowe's ojGreenville NC
Date: 2/26/2007
By: S. Pruitt Checked By: P. Rivers
Directions:
> It may be advantageous to split the development into separate catchments to be handled by separa te BMPs. The tables below allo
the development to be split into as many as three catchments, and can be copied for greater than three. NOTE: Unless runoff flowin
onto the development from offsite is routed separately around or through the site, the offsite catchm ent area draining in must be
included in the acreage values of the appropriate land use(s) and treated.
> Above each table: Enter the catchment acreage in the top green blank. Based on a comparison of the post-development TN and T
export coefficients you calculated above to the rule requirements of 4.0 Ib/ac/yr TN and 0.4 lb/ac/yr TP, select BMP(s) from the list
treating the catchment runoff. Enter the chosen BMP(s) nutrient removal rates in the green blanks. If more than one BMP is to be
used in series, the combined removal rates will be calculated automatically in the blue blanks.
> Catchment Tables: Enter the acres of each type of land cover in the green boxes. The spreadsheet will calculate all of the light bl
boxes. NOTE: Compare the Total Catchment Acreage for the Development (final table) to the value you established in the pre-BMP
worksheet tables, and also to the site plans, for consistency. All of these values need to be the same
TN TP Design Standard
BMP Wet Detention Pond 25 40 NC BMP Manual
Nutrient Stormwater Wetland 40 35 NC BMP Manual
Removal Sand Filter 35 45 NC BMP Manual
Rates Bioretention 35 45 NC BMP Manual
Grass Swales 20 20 NC BMP Manual
Vegetated Filter Strip w/
20 35
NC BMP Manual
Level Spreader
Dry Detention 10 10 NC BMP Manual
Catchment 1:
Total acreage of catchment 1 = ac
First BMP's TN removal rate = % First BMP's TP removal rate =
Second BMP's TN removal rate = % Second BMP's TP removal rate =
Third BMP's TN removal rate = % Third BMP's TP removal rate =
TOTAL TN REMOVAL RATE = 72.648 % TOTAL TP REMOVAL RATE = 83.995
(1) (2) (3) (4) (5) (~ (7)
Type. of Land Cover Catchment S.M. Formula Average EMC o Column Average EMC o Column
Acreage (0.51 +A.1 I) TN (mg/L) (2) • (3) • (4) TP (mg/L) (2) • (3) * (ti)
Transportation impervious 7.95 2.60 94.82 0.19 6.93
Roof impervious 7.95 1.95 68.02 0.11 3.84
Managed pervious 7.95 1.42 11.40 0.28 2.25
Wooded pervious 7.95 0.94 0.00 0.14 0.00
Area taken up by BMP 7.95 1.95 15.49 0.11 0.87
Pre-BMP TN Pre-BMP TP
Fraction Impervious (I) = 0.82 189.73 13.89
Load (Ib/yr) Load (Ib/yr)
Total Area of Development = 10.99 Pre-BMP TN 17 26 Pre-BMP TP 1.26
Export (Ib/ac/yr Export (Ib/ac/yr
Post-BMP T Post-BMP T
51.90 2 22
Load (Ib/yr) Load (ib/yr)
Post-BMP T
4.72 Post-BMP T
0.20
Export pb/ac/yr Export (Ib/ac/yr
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l ar-F'amllCO JtOrmWater KUIe 16N NC:HGLtf . ULbtf
past roioameo 5/L3N3
Catchment 2:
Total acreage of catchment 2 = ac
First BMP's TN removal rate = % First BMP's TP removal rate =
Second BMP's TN removal rate = % Second BMP's TP removal rate =
Third BMP's TN removal rate = % Third BMP's TP removal rate =
TOTAL TN REMOVAL RATE = 72.16 % TOTAL TP REMOVAL RATE = 79.0192
(1) (2) (3) (4) (5) (6) (7)
Type of Land Cover Catchment S.M. Formula Average EMC o Column Average EMC o Column
Acreage (0.51 + 9.1 I) TN (mg/L) (2) * (3) * (4) TP (mg/L) (2) * (3) * (6)
Transportation impervious 6.33 2.60 66.19 0.19 4.84
Roof impervious 6.33 1.95 2.35 0.11 0.13
Managed pervious 6.33 1.42 15.92 0.28 3.14
Wooded pervious 6.33 0.94 0.00 0.14 0.00
Area taken up by BMP 6.33 1.95 7.41 0.11 0.42
Fraction Im ervious
p m =
0.64 Pre-BMP TN
91.86 Pre-BMP TP
8.53
Load (Ib/yr) Load (lb/yr)
Pre-BMP TN Pre-BMP TP
Total Area of Development = 6.58 13.96 1.30
Export (Ib/ac/yr Export (ib/ac/yr
Post-BMP T Post-BMP T
25.57 1.79
Load (Ib/yr) Load (Ib/yr)
Post-BMP T 3.89 Post-BMP T 0.27
Export (Ib/ac/yr Export (lb/ac/yr
Catchment 3:
Total acreage of catchment 3 = ac
First BMP's TN removal rate = % First BMP's TP removal rate =
Second BMP's TN removal rate = % Second BMP's TP removal rate =
Third BMP's TN removal rate = % Third BMP's TP removal rate =
TOTAL TN REMOVAL RATE = 0 % TOTAL TP REMOVAL RATE = 0
(1) (2) (3) (4) (5) (6) (7)
Type of Land Cover Catchment S.M. Formula Average EMC o Column Average EMC o Column
Acreage (0.51 + 9.1 I) TN (mg/L) (2) * (3) * (4) TP (mg/L) (2) * {3) * (6)
Transportation impervious 0.73 2.60 0.00 0.19 0.00
Roof impervious 0.73 1.95 0.14 0.11 0.01
Managed pervious 0.73 1.42 2.19 0.28 0.43
Wooded pervious 0.73 0.94 1.32 0.14 0.20
Area taken up by BMP 0.73 1.95 0.00 0.11 0.00
Fraction Impervious (I) = 0.02 Pre-BMP TN 3.66 Pre-BMP T 0.64
Load (Ib/yr) Load (ib/yr)
Total Area of Development = 4.13 Pre-BMP TN 0 89 Pre-BMP T 0.15
Export (IbJac/yr Export (Ib/ac/yr
Post-BMP T
3.66 Post-BMP T
0.64
Load (Ib/yr) Load (Ib/yr)
Post-BMP T
0.89 Post-BMP T
0.15
Export (Ib/ac/yr Export (Ib/ac/yr
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Tar-Pamlico Stormwater Rule 15A NCAC 28 .0258
Last Modrtied b/13/U3
Weighted Average of Nutrient Loadiugs.frone the Catchments:
Catchment
Acreage Post-BMP
TN Loading
(Ib/ac/yr) Post-BMP
TP Loading
(Ib/ac/yr)
Catchment 1 10.99 4.72 0.20
Catchment 2 6.58 3.89 0.27
Catchment 3 4.13 0.89 0.15
TOTAL FOR DEVELOPMENT 21.70 3.74 0.21
Note: The nutrient loading goals are 4.0 lb/ac/yr for TN and 0.4 Ib/ac/yr for TP. If the post-development nutrient
loading is below these levels, then the BMPs planned are adequate. Otherwise, additional BMPs and/or
modifications in development plans are required.
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APPENDIX H
NCDENR Worksheets
(Wet Detention)
(Level Spreader)

Project No. DWQ (to be provided by DWQ)
DIVISION OF WATER QUALITY - 401 N BASIN WORKSHEET
' DWQ Stormwater Management Plan Review: ~~~..._L_ ~ ,, 1~1 _ __I r
A complete stormwater management plan submittal includes a wet[•IdetewntiCoTntbOtas~in-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 INFORMAT]~ON please comp t t e following information):
Project Name : GO Q{ IrP ul k
Contact Person: t CrS Phone Number: .'Z e1- 2.
For projects with multiple basins, specify which basin this worksheet applies to: ~'
' Basin Bottom Elevation ~ ft. (average elevation of the floor of the basin)
Permanent Pool Elevation ft. (elevation of the orifice invert out)
' Temporary Pool Elevation - ft. (elevation of the outlet structure invert in)
Permanent Pool Surface Area ~~ ~~~ sq. ft. (water surface area at permanent pool elevation)
Drainage Area 0 , 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 ~ 2 cu. ft. (combined volume of main basin and forebay)
' Temporary Pool Volume 3 1 33 Z cu. ft. (volume detained on top of the permanent pool)
Forebay Volume ~4 1 ~ ~! cu. ft.
SA/DA used ~ (surface area to drainage area ratio)
Diameter of Orifice Z, 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 2H .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
' The temporary pool controls runoff from the 1 inch storm event.
The basin length to width ratio is greater than 3:1.
The basin side slopes are no steeper than 3:1.
A submerged and vegetated perimeter shelf at less than 6:1 is provided.
Vegetation to the permanent pool elevation is specified.
An emergency drain is provided to drain the basin.
' The permanent pool depth is between 3 and 6 feet (required minimum of 3 feet).
~ S The temporary pool draws down in 2 to 5 days.
0. The forebay volume is approximately equal to 20% of the total basin volume.
Sediment storage is provided in the permanent pool.
' Access is provided for maintenance.
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.
A debris check is specified in the 0&M plan to be performed after every storm event.
' A specific sediment clean-out benchmark is listed (elevation or depth) in O&M plan.
A responsible party is designated in the O&M plan.
FORM SWG100 09/97 Page 1 of 1
' ~~

' Project No. DWQ (to be provided by DWQ)
DIVISION OF WATER QUALITY - 401 - BASIN WORKSHEET
DWQ Stormwater Management Plan Review: ~~~1N _L ~. ~ ~ l,,e j,1
' A com lete stormwater mana ement lan submittal includes a wet detention asin worksheet for each basin
P g P b >
' 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 lease com lete the following information):
Project Name : LO 5 0~ vi ~ NC+
Contact Person: tl~lrttlc IZtV[rS Phone Number: (Bt~~/1 .1UZ• !o ~7 a
For projects with multiple basins, specify which basin this worksheet applies to: ~A ~t 2
Basin Bottom Elevation 39 ft. (average elevation of the floor of the basin)
Permanent Pool Elevation 9 ft. (elevation of the orifice invert out)

' Temporary Pool Elevation ~/O . J ft. (elevation of the outlet structure invert in)
Permanent Pool Surface Area ~T s3 2- s . ft.
q water surface area at ermanent ool elevation
( p P )

' Drainage Area
Impervious Area (e.'~~ ac.
~• 2) ac. (on-site and off-site drainage to the basin)
(on-site and off-site drainage to the basin)
Permanent Pool Volume ~~ cu. ft. (combined volume of main basin and forebay)
' Temporary Pool Volume / 9 cu. ft. (volume detained on top of the permanent pool)
Forebay Volume y'~S'9.S cu. ft.
SA/DA used ~~ (surface area to drainage area ratio)
Diameter of Orifice j 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 2H .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
' The temporary pool controls runoff from the 1 inch storm event.
The basin length to width ratio is greater than 3:1.
The basin side slopes are no steeper than 3:1.
A submerged and vegetated perimeter shelf at less than 6:1 is provided.
Vegetation to the permanent pool elevation is specified.
An emergency drain is provided to drain the basin.
' The permanent pool depth is between 3 and 6 feet (required minimum of 3 feet).
C~a~(S The temporary pool draws down in 2 to 5 days.
eZ t) • ~ The forebay volume is approximately equal to 20% of the total basin volume.
Sediment storage is provided in the permanent pool.
' Access is provided for maintenance.
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.
A debris check is specified in the O&M plan to be performed after every storm event.
' A specific sediment clean-out benchmark is listed (elevation or depth) in O&M plan.
A responsible party is designated in the O&M plan.
FORM SWG100 09/97 Page 1 of 1
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DIVISION OF WATER QUALITY -LEVEL SPREADER WORKSHEET (112007)
I. PROJECT INFORMATION (please complete the following information):
Project Name : Lowe's of Greenville NC
Contact Person: Patrick Rivers Phone Number: [phone]
Level Spreader ID: Pond #1 Outlet
Level Spreader Length
Drainage Area
Impervious Area
Forebay Area
Maximum Filter Strip/Buffer Slope
133 ft.
10.99 ac.
8.98 ac.
54146 cu ft.
8
Max. Discharge from 1 "/Hr Storm 0.19 cfs
Max. Discharge to Level Spreader 3.4 cfs
Filter Strip/ Zone 1 Buffer Vegetation strip grass
Filter Strip/ Zone 1 Buffer Width nia ft.
' Filter Strip/ Zone 2 Buffer Vegetation
Filter Strip/ Zone 2 Buffer Width ft.

1

Bypass Method Used n/a
(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 grass/thick cover)
(Discharge rate from extended detention wetland or pond)
(Grass/Thick ground cover or Forested)
Please include a worksheet for this.
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, please explain 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

u
Project Site was visited prior to designing level spreader system.
Date of the Site visit. Please attach time-dated digital photos of existing buffer conditions.
Level spreader length is at least:13 ft. per cfs for thick ground cover /grass; OR 65 ft per cfs for 50-
footcanopied forest with leaf litter; 50 ft per cfs for 100-foot forested buffer; 40 ft. per cfs for 150-foot
forested buffer; OR a weighted average of the two vegetation types within the buffer/filter strip).
All ground cover types and their widths have been labeled on the construction plans.
All contours have been depicted on the construction plans.
No structures are located in protected buffers (must meet no practical alternatives criteria).
No draws are located in the buffer or filter strip in the vicinity of the proposed level spreader.
Construction details for the level spreader have been provided.
The operation and maintenance agreement signed and notarized by the responsible party is provided.
No practical alternatives explanation + Variance request. (Level Spreaders in Series only).
Bypass method used:
Bypass conveyance method is specified and construction 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.
Construction details for the bypass and outlets are provided.
N-3

' DIVISION OF WATER QUALITY -LEVEL SPREADER WORKSHEET (112007)
t I. PROJECT INFORMATION (please complete the following information):
Project Name : Lowe's of Greenville NC
' Contact Person: Patrick Rivers Phone Number: [phone]
Level Spreader ID: Pond #2 Outlet
' Level Spreader Length 32 ft. (perpendicular to flow)
Drainage Area 6.58 ac. (on-site and off-site drainage to the level spreader)
Impervious Area 4.21 ac. (on-site and off-site drainage to the level spreader)
' Forebay Area 28595 cu ft. (0.2% of the contributing impervious surface area)
Maximum Filter Strip/Buffer Slope 8 % (6% for forested/leaf littler cover, 8% for grass/thick cover)
1 Max. Discharge from 1"/Hr Storm 0.04 cfs
Max. Discharge to Level Spreader 2.4 cfs (Discharge rate from extended detention wetland or pond)
Filter Strip/ Zone 1 Buffer Vegetation strip_ grass (Grass/Thick ground cover or Forested)
Filter Stripl Zone 1 Buffer Width n/a ft.
' Filter Strip/ Zone 2 Buffer Vegetation
Filter Stripl Zone 2 Buffer Width ft.
' Bypass Method Used n/a Please include a worksheet for this.
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 requiremenf has not been met, please explain 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
Project Site was visited prior to designing level spreader system.
Date of the Site visit. Please attach time-dated digital photos of existing buffer conditions.
Level spreader length is at least: 13 ft. per cfs for thick ground cover /grass; OR 65 ft per cfs for 50-
foot canopied forest with leaf litter; 50 ft per cfs for 100-foot forested buffer; 40 ft. per cfs for 150-foot
forested buffer; OR a weighted average of the two vegetation types within the buffer/filter strip).
All ground cover types and their widths have been labeled on the construction plans.
All contours have been depicted on the construction plans.
No structures are located in protected buffers (must meet no practical alternatives criteria).
No draws are located in the buffer or filter strip in the vicinity of the proposed level spreader.
Construction details for the level spreader have been provided.
The operation and maintenance agreement signed and notarized by the responsible party is provided.
No practical alternatives explanation + Variance request. (Level Spreaders in Series only).
Bypass method used:
' Bypass conveyance method is specified and construction 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.
Construction details for the bypass and outlets are provided.
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