SW4210501_Design Calculations_20210525

Storm Wafer & Erosion Control
Design Calculations
April 27, 2021
Dollar General Store
3340 S. NC Hwy 62
Burlington, NC
Alamance County
Prepared for:
Glandon Forest Equity, LLC
3825 Barrett Drive, Suite100
Raleigh, NC 27609
(919) 459 —2 601
Prepared by:
Triangle Site
Design, PLLC
4004 Barrett
Drive, Suite 101
Raleigh, NC
27609
[phone]
NC License#P-0619
TRIANGLE
S I T E D E S I G N

TABLE OF CONTENTS
OVERVIEW
STORM WATER NARRATIVE
FIGURES
SOILS SURVEY & SOIL INFORMATION
USGS TOPOGRAPHIC MAP
FEMA FIRM MAP
SURFACE WATER CLASSIFICATIONS
HUC
NOAA POINT PRECIPATION FREQUENCY ESTIMATES
DRAINAGE AREA MAPS
GEOTECHNICAL ENGINEERING REPORT
WATER QUANTITY/QUALITY
WET DETENTION POND
NCDEO BMP SUPPLEMENT
CN VALUES
PRE -DEVELOPMENT HYDROGRAPHS
POST -DEVELOPMENT HYDROGRAPHS
TIME VS. VOLUME (STORAGE)
TIME VS. ELEVATION (STAGE)
ELEVATION -VOLUME -FLOW SUMMARY
POND OUTLET/STRUCTURE SUMMARY
TIME OF CONCENTRATION
STORM DRAIN SYSTEM
GRASS CHANNEL
EROSION CONTROL CALCULATIONS
RIP -RAP APRON
SKIMMER BASIN
ANTI -FLOTATION CALCULATIONS
TEMPORARY DIVERSION DITCH

OVERVIEW
ack ra d'
This report contains the storm water and erosion control calculations for the proposed
Dollar General retail site. The project site is located along S. NC Hwy 62 in Alamance
County near the intersection with S. NC Hwy 62 and Porter Sharpe Rd and is currently
undeveloped. The proposed project site consists of 2.03 acres and approximately 1.88
acres will be disturbed as part of this project for the construction of the site
improvements.
The development of the site will result in an impervious area of 38,841sf (0.89ac -
43.91 % impervious).
The proposed Dollar General parcel is not located within a FEMA designated flood zone as
shown on FEMA FIRM Panel 3710884200K with an effective date of 6/18/07. Flood
zones are subject to change by FEMA.
There are no existing stream or wetland features on the proposed property.
The proposed site is within the Cape Fear river basin,
The proposed storm water management facility (wet detention pond —retention basin
outlined in this report has been designed to treat the impervious areas of the
development. The site grading and storm drainage systems are designed to convey
stormwater runoff from the impervious areas of the site to the wet detention pond. The
pond is designed to treat a drainage area of 1.12ac with an impervious area of 0.870c.
The balance of the site is open space and will by—pass the proposed pond. The pond
is designed to treat a 1.0" storm event.
Erosion Control
Erosion control measures have been designed in accordance with NCDEQ erosion control
standards and regulations to minimize sediment laden runoff from exiting the site. Silt
fence will be installed along the low sides of the site prior to construction. The
construction entrance will be installed prior to construction commencing. Inlet protection
will be installed around all existing inlets and will be utilized for the proposed curb inlets
and drop inlets. A skimmer basin will be used to treat stormwater runoff prior to
leaving the site. Accumulated sediment within the project site will need to be removed
and the pond constructed to final design conditions prior to final acceptance of the
project.

Soils
The County Soils Survey indicates that Cullen Clay Loam soils are present on the site.
Attached in the Figures Section is the geotechnical engineering report which includes site
specific information regarding the site investigation and soil profile. Soil Boring B-1 at
the proposed wet pond shows a water depth of 12.Oft. The permanent pool elevation is
657.0 and the existing ground elevation is approximately 657.5 at the outlet control
structure.
Site Stabilization
After final grading is completed, permanent vegetation shall be applied in accordance
with the seeding requirements and landscape plan for this site.

FIGURES

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Hydrologic Soil Group—Alamance County, North Carolina
Hydrologic Soil Group
Map unit symbol Map unit name
CnB2 Cullen clay loam, 2 to 6 B
percent slopes,
moderately eroded
Totals for Area of Interest
Description
Rating
Acres in AOI Percent of AOI
3.1 100.0%
3.1 100.0%
Hydrologic soil groups are based on estimates of runoff potential. Soils are
assigned to one of four groups according to the rate of water infiltration when the
soils are not protected by vegetation, are thoroughly wet, and receive
precipitation from long -duration storms.
The soils in the United States are assigned to four groups (A, B, C, and D) and
three dual classes (A/D, B/D, and C/D). The groups are defined as follows:
Group A. Soils having a high infiltration rate (low runoff potential) when
thoroughly wet. These consist mainly of deep, well drained to excessively
drained sands or gravelly sands. These soils have a high rate of water
transmission.
Group B. Soils having a moderate infiltration rate when thoroughly wet. These
consist chiefly of moderately deep or deep, moderately well drained or well
drained soils that have moderately fine texture to moderately coarse texture.
These soils have a moderate rate of water transmission.
Group C. Soils having a slow infiltration rate when thoroughly wet. These consist
chiefly of soils having a layer that impedes the downward movement of water or
soils of moderately fine texture or fine texture. These soils have a slow rate of
water transmission.
Group D. Soils having a very slow infiltration rate (high runoff potential) when
thoroughly wet. These consist chiefly of clays that have a high shrink -swell
potential, soils that have a high water table, soils that have a claypan or clay
layer at or near the surface, and soils that are shallow over nearly impervious
material. These soils have a very slow rate of water transmission.
If a soil is assigned to a dual hydrologic group (A/D, B/D, or C/D), the first letter is
for drained areas and the second is for undrained areas. Only the soils that in
their natural condition are in group D are assigned to dual classes.
Rating Options
Aggregation Method. Dominant Condition
USDA Natural Resources
Conservation Service
Web Soil Survey
National Cooperative Soil Survey
Page 3 of 4

Hydrologic Soil Group—Alamance County, North Carolina
Component Percent Cutoff.- None Specified
Tie -break Rule: Higher
USDA Natural Resources
•� Conservation Service
Web Soil Survey
National Cooperative Soil Survey
3/23/2021
Page 4 of 4

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Surface Water Classifications:
Stream Index:
16-19-(2.5)
Stream
Big Alamance Creek
Name_
(Alamance CreekKLake
Mackintosh)
v
Description:
From a point 2-4 milesP
downstream of Guilford
s"
County SR 3045 to dam at
3
Lake Mackintosh
Classification:
WS-IV;NSW,CA
'
Date of
August 2 1992
Class.:
Whatdoes
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mean?
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River Bas-n:
Cape Fear
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c1 12-Digit HUC (Subwatershed)
f 12-Digit Name: Lower BigAlamance Creek '
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12-Di-•ii Code: 030300020310 Y
ICI -Digit Name: BigAlamanceCreek
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10-Digit Code: 0303000203 -+
1 18-Di-it Code: 03030002
River Basin: Cape Fear
U. 12 -Digit Area (ac): 21,629.00'
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National Geographic, Esri, Garmin, HERE. UNEP-WCMC, USGS, NASA, ESA, N
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NOAA Atlas 14, Volume 2, Version 3
Location name: Burlington, North Carolina, USA*
Latitude: 36.01341, Longitude:-79.612'ME
Elevation: 661.86 ft**
'source: ESRI Maps
source: USGS
POINT PRECIPITATION FREQUENCY ESTIMATES
G.M. Bonnin, D. Martin, B. Lin, T Parcybok, M.Yekta, and D Riley
NOAA, National Weather Service, Silver Spring, Maryland
PF tabular I PF graphical I Maps & aerials
PF tabular
PDS-based point precipitation frequency estimates with 90% confidence intervals (in inches)1
Average
recurrence interval (years)
Duration
1
2
10
25
501
160
200
500
1000
5�itin
(0 358-0 428
0 426-0 509
(0. 95-0 592
(0.540-0 645)
(0.586 0 703
(0.614.0 740
0.638A.772
0.655 O7 97
0.668-0 821
(0 6774-0 836
10�rlin
0 572 n 684
0.682- 814
0.79 -0.947
0.863-1 93
0 934-1312}
0 978-1818
(1 01-1 23)
1 (1,04 1.26
(1.06-1 IQ)
1 (1 06--1032)
15�rlin
0
(0.715-0855
0.8593502
1.00-11..20
1.09--1.31
1.6-31042)
124--149
12841255
1.31-41660
1.335.64
133--1.65
1.07
1.29
1.56
1.73
1.93
2.06
2.18
2.27
2.38
1 2.45
30�rlin
(0.981-1.1
1 18-1.41]
j (1.42-1.70)
1 (1.58-1 89
1.75-2 101
1 (1 87-2 25)
1 (1.96-2.38)
2.04-2.48)
2 12-2.60
(2.16-2.68)
60�nin
1 22-1 46
1.49--1277
1. 3-218
2 6 2646
2 34 2780
2 53 3904
2 0-3027
2. 639.48
3. 4 3-71 �73
3. 5--3�91
095
3.
2-hr
1 45--1 72
1.75 2.09
2.12732.59
2.47 2
2.84-13.40
3 0-3 74
3. 5-4.06
3.5804.37)
3 87 4977
4 6-5.06
1.69
2.05
2.54
2.91
3.37
3.72
4.06
4.38
4.81
5.11
3-hr
1 55-1 84
(1.89-2 23
2.34-2.77
2.67-3.16)
(3 07-3 65)
(3 37-4.02
3 65-4.39)
(3.91-4.74)
(4.24-5.20)
(4 47-5 54)
6-hr
2.0-5
1 89-2 23
2.48
2 29-2.70)
3.08
(2.83-3 35)
3.53
(3 24-3 83)
4.13
(3 77-4 47)
4.60
1 (4.164.9
5.07
4.55-5.47
5.53
4,91-5.97
6.16
(5.39-6.65)
6.64
1 (5 73-7 18)
12-hr
2 5 68 .
2;72 3522
3. 8-4,01
3.904 63]
(4 8 5446)
{5 11 6712
5 63 6180
6. 597..51)
{6 4 8051)
{7 4 9330)
734
88
24-hr
2 6783.08
3.22 3671
4.01 4163
4 62 5
(5 43 6732)
(6 07---7909
6 72-37186
7.38 8670
8. 6 9883
(8 4- 0.7
3.34
4.02
4.97
5.69 7F
6.66
7.42
8.18
8.96
10.0
10.8
2�ay
(3 133 58)
3.76-4.31
(4.65.5.33) 11
(5.32-6.11) 11
(6.20-7.15)
6.88-7.98)
1 (7.55-8.82)
(8.24-9.88)
(9.16-10.9)
1 (9 87-11.8
3�ay
3 31-3479
3. 8-4.55
4. 0 5360)
(5. 0 6942
(6 2--752
7.24 8139
7.97 9.29
8. 0-4102
9.68--111.5
(10.4-12.5
4 day
3 9 3399
11
4 9 4779
5.14 596
5 6 6973
6 537689
7 61 8181
8.38 9 6
9. 6�10.7
10.2- 2 1
1110-13 1)
7�ay
(4. 24.56)
4.79 5943
5. 0-6 58
6. 007350
(7 6 8874)
8. 919 74)
9.310 0.6)
(10 2-101.8)
1 (113-13.3
(12.2-14.4
10{tay
4.84
4 56-5 16
5.75
5 42-6.14
6.91
6.50-7.37
7.81
7.34-8,33
9.04
8.45-9 65
9.32-10 7)
F--ii-.-O--Jl
10 2-11.8]
12.0
1 (11 1-12.B
11 13.3 11
12.2-14.4)
14.4
1 (13.1-15.5
686
409
3
20�ay
6 2 6
(7.22 8
8.53 956
(9 56-10.7
(10 9- 2 4
1210- 3.7
4
13 115.0
6 (14.2 .3
(156-1 B.2
1
161 8- 9.7
11
30�ay
7 4 8463
8 8 9594
10 4-O .5
11 5-12.8
(13.0-14 4)
14 14 5.7
15 161TD]
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1827--21 4
10.2
11.9
13.6
15.0
16.7
18.1
19.4
20.8
22.5
23.8
45�ay
(9 68 10.7)
1 (11.3-12.5)
{13.0-14.3)
(14.2-15.7
15.9-17.6
17.1-19.0
18.3-20.5]
19.5-21.9
(21.0-23.8)
22.2-25.3
4.2
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3
2
2,,2
5
7
14
16
167-8.3
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196-21 6
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9 24.3
23
24427.4
t Precipitation frequency (PF) estimates in this table are based on frequency analysis of partial duration series (PDS).
Numbers in parenthesis are PF estimates at lower and upper bounds of the 90% confidence interval The probability that precipitation frequency estimates (for a
given duration and average recurrence interval) will be greater than the upper bound (or less than the lower bound) is 5% Estimates at upper bounds are not
checked against probable maximum precipitation (PMP) estimates and may be higher than currently valid PMP values
Please refer to NOAA Atlas 14 document for more information.
Back to Top
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GooTechnologies,
Geotechnical and Construction Materials Testing Services
April 19, 2021
Ashley Davis
GLANDON FOREST EQUITY, LLC
3825 Barrett Drive, Suite 100
Raleigh, NC 27609
Re: Subsurface Investigation
Proposed Dollar General Store
NE Intersection of Porter Sharpe Road/Highway 62
Burlington, North Carolina
GeoTechnologies Project No. 1-21-0288-EA
Dear Ms. Davis:
GeoTeclmologies, Inc. has completed test borings to evaluate subsurface soil conditions for the referenced
project located at the northeast intersection of Porter Sharpe Road and Highway 62 in Burlington, North Carolina.
Subsurface conditions were investigated by completing nine soil test borings at the approximate locations shown on the
attached Figure 1. The boring locations were established in the field by measuring distances off existing site landmarks
and should be considered approximate. The test borings were advanced to termination depths of approximately 10 to
20 feet below site grade utilizing standard penetration test procedures (automatic hammer) at selected intervals to
evaluate the consistency and density of the subsurface soils. This report presents the findings of our investigation and
our recornmendations regarding site grading and foundation support considerations.
SITE AND PROJECT INFORMATION
It is our understanding that a vacant and open parcel at the northeast intersection of Porter Sharpe Road and
Highway 62 will be developed with a Dollar General store. The Dollar General store will encompass about 10,000
square feet of space, with pavements to the south and west of the building.
Plan grades were not provided; however, we anticipate that cuts and fills will generally be less than about 5 '
feet. Based on our experience with similar projects, we expect that maximum column loads will be about 90 kips with
walls loads not exceeding 2 to 3 khf.
SUBSURFACE CONDITIONS
A generalized subsurface profile prepared from the test boring data is attached to this report as Figure 2 to
graphically illustrate subsurface conditions encountered at this site. More detailed descriptions of the conditions
encountered at the individual test boring locations are then presented on the attached test boring records.
Conditions in the borings consisted of a surface layer of topsoil which was underlain by residual clays and silts
which were typically highly plastic and exhibited penetration resistances of 4+ blows per foot (bpf). With depth, the
soils were typically low to high plasticity silts which exhibited penetration resistances of 2 to 10+ bpf. The borings
were terminated in these soils at depths of 10 to 20 feet.
Groundwater was encountered in the deeper borings at about 11.5 to 12.5 feet at the time of completion. It
should also be noted that the near surface soils at this site are conducive to the temporary development of perched
groundwater conditions during periods of wet weather and that groundwater levels will fluctuate during different
periods of the year.
3200 Wellington Cl., Ste 108 • Raleigh, NC 27615 • Phone [phone] • Fax [phone] • www geotechpa.com - License No. C-0894

Re: Dollar General Store
April 19, 2021
Page: 2
RECOMMENDATIONS
The following recommendations are made based upon a review of the attached test boring data, our
understanding of the proposed construction, and experience with similar projects and subsurface conditions. Once
structural and civil drawings are available, that information should be provided to us so that our recommendations can
be extended or modified as necessary.
Site Grading Considerations. Site grading should begin with stripping of all topsoil. Exposed subgrade
evaluations should consist of proofrolling with a loaded dump truck and performing hand auger borings. Repairs should
be performed as directed by the geotechnical engineer. Our borings indicate that the need for undercut repair should be
limited to 12 to 24 inches or less in most areas. Provided that soils which are soft to no more than 12 inches can be
moisture conditioned and recompacted as necessary, undercut can be reduced.
The site should be graded during a period of warm and dry weather. During an average year, the best time of
the year for site work occurs from about April through October. If the site is graded during an unfavorable period,
undercut quantities will increase as shallow drying/recompacting type repairs will not be effective during this time of
year. Drying will also not be effective if the contractor does not provide a farm disc to turn wet soils. As such; contractor
documents should require that a disc be provided as needed.
Borrow Sources/Fill Placement. The near surface site profile is typically highly plastic silts and clays which
should not be reused as structural fill within 3 feet of subgrade in the building pad, and within 12 inches of subgrade in
pavement areas. Additionally, these soils were moist to wet in some areas. In order to achieve density and stability, all
fill soils should be compacted within about 2% of optimum moisture content unless otherwise directed by the
geotechnical engineer. As such, the contractor should be prepared to moisture condition (wet or dry) the soils as
necessary. Attempting to dry and compact wet soils during a wet period of the year will be difficult.
If off -site borrow is needed, we recommend this material consist of silty and clayey sands or low plasticity silts
and clays having Unified Soil Classifications of SM, SC, NIL, or CL. All fill materials in structural and pavement areas
should be compacted to not less than 95% of the standard Proctor maximum dry density except in the final foot where
this requirement should be increased to 98%. In order to achieve density and stability, the soils should be compacted
within about 2% of optimum moisture content unless otherwise directed by the geotechnical engineer.
Fill Induced Settlements. In any area where site grade will be raised by more than 5 feet, some settlement of
the underlying soils will occur. It is recommended that fill induced settlements be allowed to subside before construction
begins. As such, we recommend that the project surveyors establish monitoring points in deep fill areas (any area with
more than 5 feet) to verify that fill induced settlements have subsided. Based on experience, we anticipate that the
monitoring period will not exceed 30 days following the completion of filling. Because fill induced settlements will
subside before paving operations, monitoring these areas is not necessary.
Difficult Excavation Considerations. The test borings did not encounter any difficult excavation type materials.
However, we recommend that contract documents clearly specify the type of equipment which will be used to
demonstrate difficult excavation. We recommend that a fair unit price be established for difficult excavation removal,
and that verification/measurement protocols be established at the start of construction. All difficult excavation
quantification should be based on bank yardage and not on loose material piles or truck load counts which are not
accurate.
GeoTechnologies,lnc.

Re: Dollar General Store
April 19, 2021
Page: 3
Shallow Foundations. Assuming the site is prepared as discussed, we have used the FHA Settlement Estimation
Procedure to estimate that column/wall loads of about 100 kips or 6 klf can be supported with the resulting settlement
being about 1 inch or less for a design bearing of 2.5 ksf with foundations bearing at least 18 inches below grade. Our
estimates should be considered preliminary in nature, and should be verified once structural and civil design drawings
are available.
Bearing conditions should be inspected by a geotechnical engineer during footing construction to verify that
adequate bearing and suitable materials have been encountered. Should foundations need to be extended to provide
adequate bearing, we recommend that over -excavated footings be backfilled to design bearing elevation utilizing
uniformly graded #57 or #67 washed stone. The stone must be compacted in lifts of 24 inches with appropriate
equipment, and must be thoroughly compacted at the top with vibratory equipment or heavy tamping. Highly plastic
soils are likely to be encountered at subgrade, and these materials should be removed from within at least 3 feet of final
grade and replaced with lean concrete unless otherwise directed by the geotechnical engineer.
Slab -on -Grades. We recommend that conventional slab -on -grades be designed for an assumed subgrade
modulus of 100 pci (for a 1 foot by 1 foot area). A minimum of 4 inches of compacted CABC stone should be placed
under all concrete slabs. Expansive soils should be removed from the upper 12 inches of the slab subgrade unless
otherwise directed by the geotechnical engineer.
Below Grade Walls and Retaining Walls. Rigid below grade walls and retaining walls with level backfill should
be designed assuming the adjacent soils will behave as an equivalent fluid having a unit weight of 60 pcf for the at -rest
condition and 45 pcf for the active earth pressure condition. These values do not account for any loading associated
with slopes or other surcharging. An equivalent fluid pressure of 250 pcf will be applicable for the passive pressure for
level ground on the front of the wall. This is an ultimate value and an appropriate safety factor should be applied. An
allowable bearing pressure of 2.5 ksf may be used for the design of below grade walls bearing on approved soils. A
design moist soil unit weight of 115 psf and a friction factor of 0.30 may also be used.
Any fill material placed adjacent to below grade walls should be compacted to a minimum of 95% of the
standard Proctor maximum dry density, except where 98% is required at subgrade. Additionally, any soils placed within
3 to 4 feet of below grade walls should be compacted with light hand held equipment to prevent overstressing of the
walls. This will necessitate that backfill be placed in 4 to 6 inch lifts. We recommend that all below grade walls be
properly waterproofed and that a drain be placed against those walls to intercept seepage and prevent a build-up of
hydrostatic pressure behind the walls. The drain should be connected to a collector drain that daylights to a down
gradient area unless a sump pump is used.
Segmental Walls. On most local projects, design parameters/specifications implicitly or explicitly exclude the
use of the on -site soils. Local import materials which are generally used in place of the on -site soils include CAB base
course stone, washed stone, granular processed fill, or screenings which are available from area quarries.
We recommend that all retaining wall designs include an assessment of global stability, to include tiered walls
and walls located in or on slopes. These analyses should be considered part of the wall design package, and designs
which do not explicitly address global stability should not be considered complete. If segmental walls will be used on
this project, we recommend that the wall designer contact us to discuss appropriate parameters.
Wall designs should include appropriate drainage provisions both directly behind the face block as well as
behind the reinforced zone. Although true groundwater is not prevalent shallow at this site, it may be encountered as
the potential for perched water exists. As such, adequate provisions should be included in the wall design details.
�N
www geotechpa com

Re: Dollar General Store
April 19, 2021
Page: 4
Slopes. The maximum angle for unreinforced fill slopes should be 2.511:1V, while steeper slopes can be used
with property designed and installed geosynthetic reinforcement Cut slopes should also be on the order of 2.5H:IV.
Steeper slopes should be reviewed and approved by the geotechnical engineer, and all out slopes and excavations for
retaining walls should be evaluated by the engineer to verify that recommended angles are appropriate for the site
specific soils.
Pavement Design. Following proper completion of grading, the site should be suitable for support of
conventional pavement structures. All pavement subgrades should be moisture conditioned and recompacted to not less
than 98% of the standard Proctor maximum dry density immediately prior to placement of base course stone. The
subgrades should also be proof tilled for stability. Due to the high potential for perched groundwater conditions to
develop during periods of wet weather, site grades should be detailed to promote drainage away from the pavement
areas, and underdrains or ditches should be provided along the high side of all pavements. Strip drains should be
provided inside all irrigated traffic islands.
Highly plastic soils should be excluded from the upper 12 inches of subgrade, and we are assuming that the
upper 12 inches of subgrade will consist of a material with a minimum design CBR value of 4% (should be confirmed
once a borrow source is identified). Specific pavement sections can be provided once traffic loading and volume details
are known; however, typical sections include 4 inches of asphalt over 8 inches of CABC stone for a heavy duty section,
and 3 inches of asphalt over 6 inches of stone for light duty areas.
Seismic Design Considerations. Based on SPT N-values, and experience in the area, the site should be given a
seismic design classification of "B".
In summary, site conditions are characterized by the presence of highly plastic silts and clays near surface.
These materials are not suitable as a borrow source for shallow fills. Provisions to handle these soils relative to
foundation, slab, and pavement construction have been provided. The on -site soils were moist to wet in some areas.
Once building loads and foundation geometries are ]mown, settlements can be evaluated in greater detail.
GeoTechnologies, Inc. appreciates the opportunity to be of service on this phase of the project. Please contact
us if you have any questions concerning this letter or if we may be of additional service on this or other projects.
Sincerely,
'1y1!lllfflllj'
n� f
L�•• *L� C�QC>','r�r
01 logles, Inc.
SEAL
Ernest L. Stitzinger, P.E.
NC Registration No. 25534
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DEPTH
(FT.)
0.0
0.2
8.0
12.0
20.0
TEST BORING RECORD
I
DESCRIPTION ELEVATION PENETRATION BLOWS PER
(FT.) (BLOWS/FT.) SIX INCHES
0 10 20 40 60 100
•I'opu,il
�1f I
Firm to Stiff Orange Clayey SILT
2-2-3
3-5-7
2-3-4
Firm Orange SILT
htl.
Nil]
2-3-3
Ez
Very Soft to Soft Orange SILT
AIL
1-1-1
1-2-2
Boring terminated at 20'
Groundwater encountered at 12' at time of boring.
JOB NUMBER 1-21-0288-EA
BORING NUMBER B- 1
DATE 4-19-21
PAGE 1 OF 1
Fro/offin"; C; e oTe h n o I o g i e s. n c
3200 Wellington Court, Ste 108
Raleigh, NC 27615
a
i
3

WATER QUALITY/QUANTITY

SUPPLEMENT-EZ COVER PAGE
FORMS LOADED
PROJECT INFORMATION
1
Project Name Dollar General Store
Project Area ac 2.03
Coastal Wetland Area ac -
2
3
4
Surface Water Area (ac)
5
Is this project High or Low Density?
High
6
1 Does this project use an off -site SCM?
No
COMPLIANCE WITH 02H.1003(4)
7
Width of vegetated setbacks provided (feet)-
8
Will the vegetated setback remain vegetated?
N/A
9
If BUA is proposed in the setback, does it meet NCAC 02H.1003(4)(c-d)?
No
10
Is streambank stabilization proposed on this project?
No
NUMBER AND TYPE OF SCMs:
11
Infiltration System
0
12
Bioretention Cell
0
13
Wet Pond
1
14
Stormwater Wetland
0
15
Permeable Pavement
0
16
Sand Filter
0
17
Rainwater Harvesting RWH
0
18
Green Roof
0
19
Level Spreader -Filter Strip LS-FS
0
20
Disconnected Impervious Surface (DIS)
0
21
Treatment Swale
0
22
Dry Pond
0
23
StormFilter
0
24
Silva Cell
0
25
113avfilter
0
26 1
Filterra
0
FORMS LOADED
DESIGNER CERTIFICATION _
27
Name and Title:
Matt Lowder, PE
28
Or anization:
Street address:
Triangle Site Design, PLLC
29
4004 Barrett Dr, Suite 101
30
City, State, Zip:
Raleigh, NC 27609
919-553-6570
31
Phone numbers :
Email:
32
[e-mail]
Certification Statement:
I certify, under penalty of law that this Supplement-EZ form and all supporting information were prepared under my direction or supervision; that the
information provided in the form is, to the best of my knowledge and belief, true, accurate, and complete; and that the engineering plans,
specifications, operation and maintenance agreements and other supporting information are consistent with the information provided here.
,���1v: ffllll►►►►''
x
z4�34 �
��ir+tts!rrtitt��
Signature of Designer ��
Date

DRAINAGE AREAS
1
Is this a hi h density ro'ect?
Yes
2
If so number of drainage areas/SCMs
1
3
Does this project have low density areas?
No
4
If so, number of low density drainage areas
0
5
Is all/part of this project subject to previous rule
versions?
No
FORMS LOADED
DRAINAGE AREA INFORMATION
Entire Site
1
4
Type of SCM
Wet Pond
Wet Pond
5
Total drainage area (sq ft
88448
48714
6
Onsite drainage area (sq ft
88448
48714
7
Offsite drainage area (sq ft)
0
0
8
Total BUA in project (sq ft
38841 sf
38022 sf
9
New BUA on subdivided lots (subject to permitting)
(sq ft
-
10[permitting)
New BUA not on subdivided lots (subject to
(sf)
-
11
Offsite BUA (sq ft
-
12
Breakdown of new BUA not on subdivided lots:
- Parking (sq ft
26385 sf
25566 sf
- Sidewalk (sq ft
1816 sf
1816 sf
- Roof (sq ft
10640 sf
10640 sf
- Roadway (sq ft)-
-
- Future (sq ft
-
-
- Other, please specify in the comment box
below (sq ft)New
13
infiltrating permeable pavement on
Isubdivided lots (sq ft
14
New infiltrating permeable pavement not on
subdivided lots (sq ft)
-
15
Existing BUA that will remain (not subject to
permitting) s ft
-
16
Existing BUA that is already permitted (sq ft
17
Existing BUA that will be removed (sq ft)-
18
Percent BUA
44%
78%
19
Design storm inches
1.0 in
20
[Design volume of SCM (cup)
3055 cf
21
Calculation method for design volume
Simple Method
DITIONAL INFORMATION
Please use this space to provide any additional information about the
22 drainage area(s):
Some area at the driveway entrance is not captured.

WET POND
1
Drainage area number 1
2
Minimum required treatment volume cu ft)_3055 cf
GENERAL
MDC FROM 02H .1060
3
Is the SCM sized to treat the SW from all surfaces at build -out?
Yes
4
Is the SCM located away from contaminated soils?
Yes
5
What are the side slopes of the SCM H: ?
3:1
6
Does the SCM have retaining walls, gabion walls or other
engineered side slopes?
No
7
Are the inlets, outlets, and receiving stream protected from erosion
10- ear storm)?
Yes
8
Is there an overflow or bypass for inflow volume in excess of the
desi n volume?
Yes
91
What is the method for dewatering the SCM for maintenance?
Pump referred
101
If applicable, will the SCM be cleaned out after construction?
Yes
11
Does the maintenance access comply with General MDC 8 ?
Yes
12
Does the drainage easement comply with General MDC (9)?
Yes
13
If the SCM is on a single family lot, does (will?) the plat comply with
General MDC N 0 ?
N/A
14
Is there an O&M Agreement that complies with General MDC (11)?
Yes
15
Is there an O&M Plan that complies with General MDC 12 ?
Yes
16
Does the SCM follow the devicespecific MDC?
Yes
17
Was the SCM designed by an NC licensedprofessional?
Yes
WETPONDMDCFROM02H.1053
18
Sizing method used
SA/DA
191
Has a stagelstorage table been provided in the calculations?
Yes
20'
Elevation of the excavated main pool depth (bottom of sediment
Iremoval) (fmsl)
650.00
21
Elevation of the main pool bottom (top of sediment removal) (fmsl)
651.00
22
Elevation of the bottom of the vegetated shelf fmsl
656.50
23
Elevation of the permanent pool fmsl)
657.00
24
Elevation of the top of the vegetated shelf (fmsl)
657.50
25
Elevation of the tem ora ool (fmsl)
658.20
26
Surface area of the main permanent pool (square feet)
2012
27
Volume of the main permanent pool (cubic feet)
4644 cf
28
Average depth of the main pool feet
3.06 ft
29
Average depth euation used
Equation 3
30
If using equation 3, main pool perimeter (feet)
189.0 ft
31
If using equation 3, width of submerged veg. shelf (feet)
3.0 ft
32
Volume of the foreba cubic feet
821 cf
331
Is this 15-20% of the volume in the mainpool?
Yes
34
Clean -out depth for foreba (inches)
36 in
35
Design volume of SCM cu ft)
3055 cf
36
Is the outlet an orifice or a weir?
Orifice
37
If orifice, orifice diameter inches
1 in
38
If weir, weir height inches
39
If weir, weir length inches
401
Drawdown time for the temporary pool (days)
2.13
41
Are the inlet(s) and outlet located in a manner that avoids short-
arcuitin ?
Yes
42
1 Are berms or baffles provided to improve the flowpath?
Yes
43
Depth of forebay at entrance (inches)
48 in
44
Depth of forebaj at exit (inches)
42 in
45
Does water flow out of the forebay in a non -erosive manner?
Yes
46
Width of the vegetated shelf feet
6 ft
47
Slope of vegetated shelf H:
6:1
48
Does the orifice drawdown from below the top surface of the
permanentpool?
Yes
49
Does the pond minimize impacts to the receiving channel from the 1
r. 24-hr storm?
Yes
50
Are fountains proposed? (If Y, please provide documentation that
MDC 9 is met.
No
51
Is a trash rack or other device provided to protect the outlet system?
Yes
52
Are the dam and embankment planted in non -clumping turf grass?
Yes
53
S ecies of turf that will be used on the dam and embankment
Hybrid Bermuda
54 1
Hasa planting plan been provided for the vegetated shelf?
Yes
ADDITIONAL
INFORMATION
55
Please use this space to provide any additional information about
the wet pond(s):
Wet Pond 1 11:01 AM 4/27/2021

Triangle Site Design, PLLC
Curve Number Calculation (CN)
Pre -Developed Conditions (Overall Site)
Drainage Area (acresL 2.03
Existing Soil Groups:
soil Group Map Symbol Soil Description Acres Percent of DA
B CnB2 Cullen clay loam 2.03 100%
Proposed Land Uses:
Land Use Description Existinq Soil Group Acres Curve # Weighted CN
Open - Good B 2.03 61 61.0
Cumulative Curve # = 61.0

Triangle Site Design, PLLC
Curve Number Calculation (CN)
Post -Developed Conditions (Wet Pond)
Drainage Area (acres)' 1.12
Existing Soil Groups:
Soil Groun Map Symbol Soil Description Acres Percent of DA
B CnB2 Cullen clay loam 1.12 100%
Proposed Land Uses:
Land Use Description Existing Soil Group Acres Curve # Weighted CN
Open Space - Good B 0.25 61 13.6
Impervious Area - Building/Pavement B 0.87 98 76.1
Cumulative Curve # = 89.7

Triangle Site Design, PLLC
Curve Number Calculation (CN)
Post -Developed Bypass Conditions (Wet Pond)
OrainaQe Area (acres 0.91
Existing Soil Groups:
Soil Grouo Map Symbol Soil Description Acres Percent of DA
B CnB2 Cullen clay loam 0.91 100%
Proposed Land Uses:
Land Use Description Existing Soil Group Acres Curve # Weighted CN
Open Space - Good B 0.89 61 59.7
Impervious Area - Building/Paveme B 0.02 98 2.2
Cumulative Curve # = 61.8

Proposed Wet Pond
Project Information
Project Name: Dollar General - Burlington
Project #:
Designed by: RG Date: 4/22/2021
Revised by: Date:
Checked by: Date:
Site Information
Sub Area Location:
Drainage To Proposed Wet Pond
Drainage Area (DA) =
1.12 Acres 48,714 sf
Impervious Area (IA) =
0.87 Acres 38,022 sf
Percent Impervious (1) =
% 78.05 %
Required Surface Area
Permament Pool Depth: 3.06 ft Non -Coastal County
SA/DA = 2.81
Min Re 'd Surface Area = 1,369 sf at Permanent Pool
Required WQv Storage Volume
Design Storm = inch Non -Coastal County
Determine Rv Value = 0.05 + .009 (1) = 0.752 in/in
Storage Volume Required = 3,055 cf (above Permanent Pool)
Elevations
Top of Pond Elevation =
659.50 ft
Temporary Pool Elevation =
658.20 ft
Permanent Pool Elevation =
657.00 ft
Shelf Begining Elevation =
657.50 ft
Forebay Weir =
656.50 ft
Shelf Ending Elevation =
656.50 ft
Bottom Elevation =
651.00 ft
Permanent Pool Area
Area @ Top of Permanent Pool = 2,012 sf
Volume of Temporary Storage = 4,125 cf
Is Permenant Pool Surface Area Sufficient (yes/no)? ( 2012 > 1369 ) sf
Volume of Storage for Design Storm = ( 4125 > 3055 ) cf

Incremental Drawdown Time
STORMWATER POND
INCREMENTAL DRAWDOWN METHOD -Water Quality Volume
Project Information
Project Nar Dollar General - Burlington
Project *:
asigned by: RG Date: 4/22/2021
iecked by: Date:
Water Quality Orifice
* Incremental Determination of Water Quality Volume Drawdown Time
Zone 2
Orifice Diameter (D) =
Cd =
Ei =
Zone 1 Range =
Zone 2 Range =
Zone 3 Range =
Q3 = 0.0437 Cp * Dz (Z-D/24-Ei)^(1m
QZ = 0.372 CD * D*(Z-Ei)^(3n)
Q,=0
1 in
0.6
657
Orifice Inv.
0.00
to 657
657
to 657.1
657.1
to 658.1
Incremental Drawdown Method
Countour
Contour
Area
Incremental
Volume
Stage, Z
Zone
Q
Drawdown
Time
sq It
cu It
ft
cfs
min
657.00
2,675
0
0.00
2.00
0.000
—
657.50
3407
1,521
0.50
3.00
0.018
1,428
658.00
3844
1,813
0.50
3.00
0.026
1,177
658.20
4069
791
0.20
3.00
0.028
467
Total
-•
4.125
--
--
--
3,072
Drawdown Time = Incremental Volume / Q / 60sec/min
Summary
Total Volume = 4,125 cf
Total Time = 3,072 min
Total Time = 2.13 days Between 2 & 5
4/27/2021 Prop Wet Pond- new design -Burlington 1 of 1

Project: Pond #1
Date: 4/27/2021
Main -Pond Contours -Volumes
Elevation
Main -Pond
Incremental Vol.
Accumulated Vol.
Description
657
2,012
871
4,644
A2 (Perm —Pool)
656.5
1,470
694
3,773
Al (Bottom —Shelf)
656
1,305
1,148
3,080
655
991
850
1,932
654
708
583
1,082
653
458
350
499
652
242
149
149
651
56
0
0
A3 (Bottom —Pond)
Forebay Contours -Volumes
Elevation
FBI
FB2 FB3 Total -Areas
657
555
555
656.5
470
470
656
318
318
655
188
188
654
41
41
Forebay Volume 17.7% *Between 15% & 20%
Average Depth (Option 1) 2.57 *At least 3' average depth
Average Depth Calculation (Option 2)
Vpp
4,644
permeter of shelf
189
width of shelf
3
Al (Bottom —Shelf):
1,470
Average Depth = 3.06
Incremental Vol. Accumulated Vol.
256 821
197 565
253 368
115 115
0 0

Proposed Wet Pond #1
Project Information
Project Name:
Project #:
Designed by:
Revised by:
Checked by:
Site Information
Dollar General - Burlington
RG Date:
Date:
Date:
4/22/2021
Sub Area Location: Drainage to Proposed Pond
Drainage Area (DA) = 1 12 Acres
Impervious Area (IA) = 0.87 Acres
Percent Impervious (1) = 78.05 % (Drainage Area)
Orifice Sizing
Orifice Size =
Drawdown Time =
less than 5 days (yes/no) ? yes
greater than 2 day (yes/no) ? yes
Anti -Flotation Device
4' x 4' Outlet Structure
in (Diameter)
days (Incremental Draw Down Method)
Area:
16.0
sf
Volume:
136.0
cf
Weight:
8486
Ibs
Factor of Safety
1.20
WT Req'd of Anti -Flotation Device:
10,184
Ibs
Volume of Concrete Req'd:
_ 67.9
cf
(Water Displaced - Top of Pond to Bottom of Pond)
(Unit WT of Concrete = 150 pcf)
Volume Provided: 77.5 cf (4'x4' riser x 2.5' =40cf, 5'x5' footing x 1.5'=37.5cf)

CMPERV
OUS
AREA
SUMMARY)
ON -SITE AREA = 88,448SF 2.03AC AFTER R W
DEDICATION
BUILDINGS
10,640 SF
0.24
ACRE(S)
12.03
% OF AREA
PAVEMENT
269385 SF
0.61
ACRE(S)
29.83
% OF AREA
SIDEWALK
19816 SF
0.04
ACRE(S)
2.05
% OF AREA
TOTAL IMPERVIOUS AREA
38,841 SF
0.89
ACRE(S)
43.91
% OF AREA
GREEN/OPEN SPACE
499607 SF
1.14
ACRE(S)
56.09
% OF AREA
INCREASE IN IMPERVIOUS AREA: 389841 SF
0.89
ACRE(S)

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"STAGE/STORAGE
TABLE
STAGE
ELEVATION
CONTOUR
INCREMENTAL
TOTAL
(FT)
(FT)
AREA (SF)
STORAGE (CF)
STORAGE (CF)
0.0
65ZO
2675
0
0
0.5
657.5
3407
1521
1521
1.0
658.0
3844
1813
3333
1.2
658.2
4069
791
4125 (WQv)
1.5
658.5
4387
1268
5393
2.0
659.0
4821
2302
7695
2.5
659.5
5270
2523
10218
STORMWATER MANAGEMENT DESIGN
WET DETENTION POND
RIVER BASIN:
RECEIVING STREAM:
STREAM INDEX:
STREAM CLASS:
HUC:
PROJECT COORDINATES:
CAPE FEAR
BIG ALAMANCE CREEK
16-19-(2.5)
WS-IV;NSW;CA
0303000203
36.013681-N,-79.51181TW
POND DESIGN SUMMARY
DRAINAGE AREA TO POND: 1.12 ACRES
SITE IMPERVIOUS AREA TO POND: 0.87 ACRES
OFF -SITE DESIGN IMPERVIOUS AREA TO POND: 0.0 ACRES
TOTAL DESIGN IMPERVIOUS AREA TO POND: 0.87 ACRES
DRAINAGE AREA:
CURVE NUMBER:
TIME OF CONCENTRATION:
1.0° STORM EVENT:
1-YEAR STORM EVENT:
2-YEAR STORM EVENT:
10-YEAR STORM EVENT:
100-YEAR STORM EVENT:
PRE -DEVELOPED
POST -DEVELOPED
POST DEVELOPED
POST DEVELOPED
POST DEVELOPED
TO POND
TO POND
THROUGH POND
BYPASS
COMPINED
2.03 AC
1.12 AC
0.91 AC
61.0
89.7
61.8
13.2 MIN
5 MIN
10 MIN
0.275 CFS
0.014 CFS
0.536 CFS
3.393 CFS
0.032 CFS
0.277 CFS
0.309 CFS
1.257 CFS
4.362 CFS
0.145 CFS
0.618 CFS
0.763 CFS
3.733 CFS
6.799 CFS
1.786 CFS
1.755 CFS
3.541 CFS
8.479 CFS
10.53 CFS
9.082 CFS
3.913 CFS
13.00 CFS

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HIRE

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7

TAD nc CTMITURE NOT SHOWN FOR CLARITY
TRASH RACK)
OUTLET CONTROL STRUCTURE - INCREMENTAL WEIR
RISER STRUCTURE
4" PVC SCREW CAP
FOR CLEANING ACCESS
12" MIN. EXTEND 4"
PVC THROUGH
RISER
STRUCTURE
4"x4" PVC TEE
PERM. POND ELEV.=657.0
12" MIN.
1 "DIA. HOLE DRILLED
INTO BOTTOM CAP
PVC DRAIN OUTLET

Pond Report s
Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2009 by Autodesk, Inc. v6.066
Tuesday, Apr 27, 2021
Pond No. 1 - BMP Pond
Pond Data
Contours - User -defined contour areas. Average end area method used for volume calculation. Begining Elevation = 657.00 ft
Stage / Storage Table
Stage (ft) Elevation (ft)
Contour area (sgft)
Incr. Storage (cult)
Total storage (cuff)
0.00 657.00
2,675
0
0
0.50 657.50
3,407
1,521
1,521
1.00 658.00
3,844
1,813
3,333
1.20 658.20
4,069
791
4,125
1.50 658.50
4,387
1,268
5,393
2.00 659.00
4,821
2,302
7,695
2.50 659.50
5,270
2,523
10,218
Culvert / Orifice Structures
[A]
[B]
[C]
[PrFRsr]
Rise (in)
= 15.00
1.00
0.00
0.00
Span (in)
= 15.00
1.00
0.00
0.00
No. Barrels
= 1
1
0
0
Invert El. (ft)
= 657.00
657.00
0.00
0.00
Length (ft)
= 22.00
0.50
0.00
0.00
Slope (%)
= 2.27
1.00
0.00
n/a
N-Value
= .013
.013
.013
n/a
Orifice Coeff.
= 0.60
0.60
0.60
0.60
Multistage
= n/a
Yes
No
No
Stage (ft)
3.00
2.00
1.00
0.00
0.00
Weir Structures
[A]
[B]
[C]
[D]
Crest Len (ft)
= 2.00
14.00
0.00
0.00
Crest El. (ft)
= 658.60
659.00
0.00
0.00
Weir Coeff.
= 3.33
2.60
3.33
3.33
Weir Type
= Rect
Broad
--•
---
Multistage
= Yes
No
No
No
Exfil.(in/hr) = 0.000 (by Contour)
TW Elev. (ft) = 0.00
Note: Culvert/Orifice outflows are analyzed under inlet (ic) and outlet (oc) control Weir risers checked for orifice conditions (ic) and submergence (s)
Stage / Discharge
2.00 4.00 6.00 8.00 10.00 12.00 14.00 16.00 18.00
Total Q
Elev (ft)
660.00
659.00
658.00
657.00
20.00
Discharge (cfs)

Hydrograph Summary Rep �ydraflow Hydrographs Extension for AutoCAD® Civil 3DO 2009 by Autodesk, Inc. v6.066
Hyd.
No.
Hydrograph
type
(origin)
Peak
flow
(cfs)
Time
interval
(min)
Time to
peak
(min)
Hyd.
volume
(cuft)
Inflow
hyd(s)
Maximum
elevation
(ft)
Total
strge used
(cuft)
Hydrograph
description
BMP Pre -Developed
1
SCS Runoff
0.536
2
724
2,380
------
------
2
SCS Runoff
3.393
2
716
6,979
------
------
------
BMP Post -Developed
3
Reservoir
0.032
2
1376
6,637
2
658.54
5,560
Post Through Pond
4
SCS Runoff
0.277
2
724
1,151
------
- --
- —
Post Developed - Pond Bypass
6
SCS Runoff
0.275
2
146
1,179
------
- --
—
BMP Post -Developed
7
Reservoir
0.014
2
364
1,120
6
657.34
1,027
1.0-in Storm Thru Pond
27, 2021
Burlington_Pond.gpw
Return Period:
1 Year
Tuesday, Apr

Hydrograph Report
Hydraflow Hydrographs Extension for AutoCADO Civil 3DO 2009 by Autodesk, Inc. v6.066
Hyd. No. 1
BMP Pre -Developed
Hydrograph type = SCS Runoff
Storm frequency = 1 yrs
Time interval
= 2 min
Drainage area
= 2.030 ac
Basin Slope
= 0.0 %
Tc method
= USER
Total precip.
= 2.86 in
Storm duration
= 24 hrs
BMP Pre -Developed
2
Tuesday, Apr 27, 2021
Peak discharge = 0.536 cfs
Time to peak
= 724 min
Hyd. volume
= 2,380 cuft
Curve number
= 61
Hydraulic length
= 0 ft
Time of cone. (Tc)
= 13.20 min
Distribution
= Type II
Shape factor
= 484
Q (cfs) Hyd. No. 1 -- 1 Year Q (cfs)
1.00 1.00
0.90 - 0.90
0.80 0.80
0.70 - — 0.70
0.60 0.60
0.50 - 0.50
0.40 0.40
0.30 - 0.30
0.20 - 0.20
0.10 0.10
I
0.00 0.00
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Hyd No. 1 Time (min)

Hydrograph Report
Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® M09 by Autodesk, Inc. v6.066
Hyd. No. 2
BMP Post -Developed
Hydrograph type - SCS Runoff
Storm frequency - 1 yrs
Time interval
2 min
Drainage area
= 1.120 ac
Basin Slope
= 0.0 %
Tc method
= USER
Total precip.
= 2.86 in
Storm duration
= 24 hrs
3.00
2.00
1.00
3
Tuesday, Apr 27, 2021
Peak discharge = 3.393 cfs
Time to peak
= 716 min
Hyd. volume
= 6,979 cuft
Curve number
= 89.7
Hydraulic length
= 0 ft
Time of conc. (Tc)
= 5.00 min
Distribution
= Type II
Shape factor
= 484
BMP Post -Developed
Hyd. No. 2 -- 1 Year
120 240 360 480 600 720 840 960
Hyd No. 2
Q (cfs)
4.00
3.00
2.00
1.00
0.00
1080 1200 1320
Time (min)

Hydrograph Report
Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2009 by Autodesk, Inc. v6.066
Hyd. No. 3
Post Through Pond
Hydrograph type = Reservoir
Storm frequency = 1 yrs
Time interval = 2 min
Inflow hyd. No. = 2 - BMP Post -Developed
Reservoir name = BMP Pond
Storage Indication method used.
Q (cfs)
4.00
cm
2.00
1.00
0.00
0 600
F-- Hyd No. 3
Post Through Pond
Hyd. No. 3 -- 1 Year
Peak discharge
Time to peak
Hyd. volume
Max. Elevation
Max. Storage
4
Tuesday, Apr 27, 2021
= 0.032 cfs
= 1376 min
= 6,637 tuft
= 658.54 ft
= 5,560 cult
1200 1800 2400 3000 3600 4200 4800 5400
Hyd No. 2 ® Total storage used = 5,560 cuft
Q (cfs)
4.00
3.00
2.00
Olif
0.00
6000
Time (min)

Hydrograph Report
6
Hydraflow Hydrographs Extension for AutoCADO Civil 3DO 2009 by Autodesk, Inc. v6.066
Tuesday. Apr 27, 2021
Hyd. No. 4
Post Developed - Pond Bypass
Hydrograph type
- SCS Runoff
Peak discharge
= 0.277 cfs
Storm frequency
= 1 yrs
Time to peak
= 724 min
Time interval
= 2 min
Hyd. volume
= 1,151 cuft
Drainage area
= 0.910 ac
Curve number
= 61.8
Basin Slope
= 0.0 %
Hydraulic length
= 0 ft
Tc method
= USER
Time of conc. (Tc)
= 10.00 min
Total precip.
= 2.86 in
Distribution
= Type II
Storm duration
= 24 hrs
Shape factor
= 484
Q (cfs
0.50 0.50
0.45 0.45
0.40 0.40
0.35 0.35
0.30 — 0.30
0.25 0.25
0.20 0.20
0.15 0.15
0.10 0.10
0.05 0.05
0.00 0.00
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Hyd No. 4 Time (min)
Post Developed - Pond Bypass
Hyd. No. 4 -- 1 Year

Hydrograph Report
Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2009 by Autodesk, Inc. v6.066
Hyd. No. 6
BMP Post -Developed
Hydrograph type =
SCS Runoff
Storm frequency =
1 yrs
Time interval =
2 min
Drainage area =
1.120 ac
Basin Slope =
0.0 %
Tc method =
USER
Total precip. =
1.00 in
Storm duration =
6.00 hrs
Q (cfs)
0.50
0.45
0.40
0.35
0.30
0.25
0.20
0.15
0.10
0.05
0.00
0
BMP Post -Developed
Hyd. No. 6 -- 1 Year
7
Tuesday, Apr 27, 2021
Peak discharge = 0.275 cfs
Time to peak
= 146 min
Hyd. volume
= 1,179 cuft
Curve number
= 89.7
Hydraulic length
= 0 ft
Time of conc. (Tc)
= 5.00 min
Distribution
= SCS 6-Hr
Shape factor
= 484
60 120 180 240 300 360
Hyd No. 6
Q (cfs)
0.50
0.45
0.40
0.35
0.30
0.25
0.20
0.15
0.10
0.05
0.00
420
Time (min)

Hydrograph Report
8
Hydraflow Hydrographs Extension for AutoCADO Civil 31DO 2009 by Autodesk, Inc. v6.066
Tuesday, Apr 27, 2021
Hyd. No. 7
1.0-in Storm Thru Pond
Hydrograph type = Reservoir
Peak discharge
= 0.014 cfs
Storm frequency = 1 yrs
Time to peak
= 364 min
Time interval = 2 min
Hyd. volume
= 1,120 cuft
Inflow hyd. No. = 6 - BMP Post -Developed
Max. Elevation
= 657.34 ft
Reservoir name = BMP Pond
Max. Storage
= 1,027 cuft
Storage Indication method used.
Q (cfs
0.50 0.50
0.45 - 0.45
0.40 0.40
0.35 0.35
0.30 0.30
0.25 0.25
0.20 0.20
0.15 0.15
0.10 0.10
0.05 - - — 0.05
0.00 - 0.00
0 240 480 720 960 1200 1440 1680 1920 2160 2400 2640 2880 3120
Hyd No. 7 Hyd No. 6 Total storage used = 1,027 cult Time (min)
1.0-in Storm Thru Pond
Hyd. No. 7 -- 1 Year

10
Hydrograph Summary Rep -H �d, raflow Hydrographs Extension for AutoCADO Civil 3DO 2009 by Autodesk, Inc. v6.066
Hyd.
No.
Hydrograph
type
(origin)
Peak
flow
(cfs)
Time
interval
(min)
Time to
peak
(min)
Hyd.
volume
(cuft)
Inflow
hyd(s)
Maximum
elevation
(ft)
Total
strge used
(cuft)
Hydrograph
description
BMP Pre -Developed
1
SCS Runoff
1.257
2
722
4,216
—
------
-
2
SCS Runoff
4.362
2
716
9,084
-----
------
------
BMP Post -Developed
3
Reservoir
0.145
2
824
8,668
2
658.66
6,149
Post Through Pond
4
SCS Runoff
0.618
2
722
2,004
---
------
Post Developed - Pond Bypass
6
SCS Runoff
0.000
2
n/a
0
--
-- -
------
BMP Post -Developed
7
Reservoir
0.000
2
n/a
0
6
657.00
0.000
1.0-in Storm Thru Pond
Burlington_Pond.gpw
Return Period: 2 Year
Tuesday, Apr 27, 2021

Hydrograph Report
Hydraflow Hydrographs Extension forAutoCAD® Civil 3D® 2009 byAutodesk, Inc. v6.066
Hyd. No. 1
BMP Pre -Developed
Hydrograph type -
SCS Runoff
Storm frequency =
2 yrs
Time interval =
2 min
Drainage area =
2.030 ac
Basin Slope =
0.0 %
Tc method =
USER
Total precip. =
3.46 in
Storm duration =
24 hrs
Q (cfs)
2.00
1.00
BMP Pre -Developed
Hyd. No. 1 -- 2 Year
120 240 360 480 600 720 840 960
Hyd No. 1
11
Tuesday, Apr 27,2021
Peak discharge = 1.257 cfs
Time to peak
= 722 min
Hyd. volume
= 4,216 cuft
Curve number
= 61
Hydraulic length
= 0 ft
Time of conc. (Tc)
= 13.20 min
Distribution
= Type II
Shape factor
= 484
Q (cfs)
2.00
1.00
0.00
1080 1200 1320 1440 1560
Time (min)

Hydrograph Report
Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2009 by Autodesk, Inc. v6.066
Hyd. No. 2
BMP Post -Developed
Hydrograph type =
SCS Runoff
Storm frequency =
2 yrs
Time interval =
2 min
Drainage area =
1.120 ac
Basin Slope =
0.0 %
Tc method =
USER
Total precip. =
3.46 in
Storm duration =
24 hrs
4.00
3.00
2.00
1.00
12
Tuesday, Apr 27, 2021
Peak discharge = 4.362 cfs
Time to peak
= 716 min
Hyd. volume
= 9,084 cuft
Curve number
= 89.7
Hydraulic length
= 0 ft
Time of conc. (Tc)
= 5.00 min
Distribution
= Type II
Shape factor
= 484
BMP Post -Developed
Hyd. No. 2 -- 2 Year
120 240 360 480 600 720 840
Hyd No. 2
Q (Cfs)
5.00
4.00
3.00
2.00
1.00
0.00
960 1080 1200 1320
Time (min)

Hydrograph Report
Hydraflow Hydrographs Extension forAutoCAD® Civil 3D® 2009 byAutodesk, Inc. v6.066
Hyd. No. 3
Post Through Pond
Hydrograph type = Reservoir
Storm frequency = 2 yrs
Time interval = 2 min
Inflow hyd. No. = 2 - BMP Post -Developed
Reservoir name = BMP Pond
Storage Indication method used.
4.00
3.00
2.00
1.00
0.00
0 600
— Hyd No. 3
Post Through Pond
Hyd. No. 3 -- 2 Year
13
Tuesday, Apr 27, 2021
Peak discharge = 0.145 cfs
Time to peak
= 824 min
Hyd. volume
= 8,668 cuft
Max. Elevation
= 658.66 ft
Max. Storage
= 6,149 cuft
1200 1800 2400 3000 3600 4200 4800 5400
Hyd No. 2 ® Total storage used = 6,149 cuft
Q (cfs)
5.00
4.00
M 11
2.00
1.00
0.00
6000
Time (min)

Hydrograph Report
14
Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2009 by Autodesk, Inc. v6.066
Tuesday, Apr 27, 2021
Hyd. No. 4
Post Developed - Pond Bypass
Hydrograph type
= SCS Runoff
Peak discharge
= 0.618 cfs
Storm frequency
= 2 yrs
Time to peak
= 722 min
Time interval
= 2 min
Hyd. volume
= 2,004 cuft
Drainage area
= 0.910 ac
Curve number
= 61.8
Basin Slope
= 0.0 %
Hydraulic length
= 0 ft
Tc method
= USER
Time of conc. (Tc)
= 10.00 min
Total precip.
= 3.46 in
Distribution
= Type II
Storm duration
= 24 hrs
Shape factor
= 484
Q (cfs
1.00 - 1.00
0.90 - 0.90
0.80 - 0.80
0.70 0.70
0.60 0.60
0.50 0.50
0.40 0.40
0.30 0.30
0.20 0.20
0.10 - - 0.10
0.00 - - 0.00
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Hyd No. 4 Time (min)
Post Developed - Pond Bypass
Hyd. No. 4 -- 2 Year

17
Hydrograph Summary Re pgaflow Hydrographs Extension for AutoCADO Civil 3DO 2009 by Autodesk, Inc. v6.066
Hyd.
No.
Hydrograph
type
(origin)
Peak
flow
(cfs)
Time
interval
(min)
Time to
peak
(min)
Hyd.
volume
(cult)
Inflow
hyd(s)
-
Maximum
elevation
(ft)
Total
strge used
(cuft)
------
Hydrograph
description
BMP Pre -Developed
1
SCS Runoff
3.733
2
722
10,267
------
2
SCS Runoff
6.799
2
716
14,545
—
------
BMP Post -Developed
3
Reservoir
1.786
2
724
14,119
2
659.00
7,719
Post Through Pond
4
SCS Runoff
1.755
2
722
4,790
-
--
------
Post Developed - Pond Bypass
6
SCS Runoff
0.000
2
n/a
0
____
------
_ ___
BMP Post -Developed
7
Reservoir
0.000
2
n/a
0
Return Period:
6
10
657.00
Year
0.000
Tuesday, Apr
1.0-in Storm Thru Pond
27, 2021
Burlington_Pond.gpw

18
Hydrograph Report
Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2009 by Autodesk, Inc. v6.066
Hyd. No. 1
BMP Pre -Developed
Hydrograph type =
SCS Runoff
Storm frequency =
10 yrs
Time interval =
2 min
Drainage area =
2.030 ac
Basin Slope =
0.0 %
Tc method =
USER
Total precip. =
4.97 in
Storm duration =
24 hrs
Q (cfs)
4.00
3.00
2.00
1.00
BMP Pre -Developed
Hyd. No. 1 -- 10 Year
120 240 360 480 600 720 840
Hyd No. 1
Tuesday, Apr 27, 2021
Peak discharge = 3.733 cfs
Time to peak
- 722 min
Hyd. volume
= 10,267 cuft
Curve number
= 61
Hydraulic length
= 0 ft
Time of conc. (Tc)
= 13.20 min
Distribution
= Type II
Shape factor
= 484
Q (cfs)
4.00
3.00
2.00
1.00
0.00
960 1080 1200 1320 1440 1560
Time (min)

19
Hydrograph Report
Hydraflow Hydrographs Extension for AutoCAD® Civil 3DO 2009 by Autodesk, Inc. v6.066 Tuesday, Apr 27, 2021
Hyd. No. 2
BMP Post -Developed
Hydrograph type
= SCS Runoff
Peak discharge
= 6.799 cfs
Storm frequency
= 10 yrs
Time to peak
= 716 min
Time interval
= 2 min
Hyd. volume
= 14,545 cuft
Drainage area
= 1.120 ac
Curve number
= 89.7
Basin Slope
= 0.0 %
Hydraulic length
= 0 ft
Tc method
= USER
Time of conc. (Tc)
= 5.00 min
Total precip.
= 4.97 in
Distribution
= Type II
Storm duration
= 24 hrs
Shape factor
= 484
BMP Post -Developed
Hyd. No. 2 -- 10 Year
M
5.00
4.00
CM
2.00
1.00
0.00
0 120 240 360 480 600
Hyd No. 2
Q (cfs)
7.00
M
4 IX
4.00
K 11
2.00
1.00
0.00
720 840 960 1080 1200
Time (min)

Hydrograph Report
20
Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2009 by Autodesk, Inc. v6.066
Tuesday, Apr 27, 2021
Hyd. No. 3
Post Through Pond
Hydrograph type =
Reservoir
Peak discharge
= 1.786 cfs
Storm frequency =
10 yrs
Time to peak
= 724 min
Time interval =
2 min
Hyd. volume
= 14,119 cuft
Inflow hyd. No. =
2 - BMP Post -Developed
Max. Elevation
= 659.00 ft
Reservoir name =
BMP Pond
Max. Storage
= 7,719 cuft
Storage Indication method used
Q (cfs)
7.00
6.00
5.00
4.00
3.00
2.00
1.00
0.00
0 480 960
Hyd No. 3
Post Through Pond
Hyd. No. 3 -- 10 Year
Q (cfs)
7.00
M
5.00
4.00
�cm
2.00
1.00
0.00
1440 1920 2400 2880 3360 3840 4320
Time (min)
Hyd No. 2 ® Total storage used = 7,719 cult

21
Hydrograph Report
Hydraflow Hydrographs Extension forAutoCAD® Civil 3D® 2009 byAutodesk, Inc. v6.066
Hyd. No. 4
Post Developed - Pond Bypass
Hydrograph type
= SCS Runoff
Storm frequency
= 10 yrs
Time interval
= 2 min
Drainage area
= 0.910 ac
Basin Slope
= 0.0 %
Tc method
= USER
Total precip.
= 4.97 in
Storm duration
= 24 hrs
Q (cfs)
2.00
1.00
Tuesday, Apr 27, 2021
Peak discharge = 1.755 cfs
Time to peak
= 722 min
Hyd. volume
= 4,790 cuft
Curve number
= 61.8
Hydraulic length
= 0 ft
Time of conc. (Tc)
= 10.00 min
Distribution
= Type II
Shape factor
= 484
Post Developed - Pond Bypass
Hyd. No. 4 -- 10 Year
120 240 360 480 600 720 840 960
Hyd No. 4
Q (cfs)
2.00
1.00
0.00
1080 1200 1320 1440 1560
Time (min)

24
Hydrograph Summary Re p `'yrraflow Hydrographs Extension for AutoCADO Civil 3DO 2009 by Autodesk, Inc. v6.066
Hyd.
No.
Hydrograph
type
(origin)
Peak
flow
(cfs)
Time
interval
(min)
Time to
peak
(min)
Hyd.
volume
(cuff)
Inflow
hyd(s)
Maximum
elevation
(ft)
Total
strge used
(cuft)
Hydrograph
description
BMP Pre -Developed
1
SCS Runoff
8.479
2
722
22,249
—
- -
--
2
SCS Runoff
10.53
2
716
23,221
-•----
-
BMP Post -Developed
3
Reservoir
9.082
2
718
22,785
2
659.29
9,095
Post Through Pond
4
SCS Runoff
3.913
2
722
10,254
------
•••
Post Developed - Pond Bypass
6
SCS Runoff
0.000
2
n/a
0
------
------
----
BMP Post -Developed
7
Reservoir
0.000
2
n/a
0
Return Period:
6
100
657.00
0.000
1.0-in Storm Thru Pond
Burlington_Pond.gpw
Year
Tuesday, Apr
27, 2021

Hydrograph Report
Hydraflow Hydrographs Extension for AutoCADO Civil 31DO 2009 by Autodesk, Inc. v6.066
Hyd. No. 1
BMP Pre -Developed
Hydrograph type =
SCS Runoff
Storm frequency =
100 yrs
Time interval =
2 min
Drainage area =
2.030 ac
Basin Slope =
0.0 %
Tc method =
USER
Total precip. =
7.31 in
Storm duration =
24 hrs
M
MI
2.00
M
BMP Pre -Developed
Hyd. No. 1 -- 100 Year
120 240 360 480 600 720 840
Hyd No. 1
W
Tuesday, Apr 27, 2021
Peak discharge = 8.479 cfs
Time to peak
= 722 min
Hyd. volume
= 22,249 cuft
Curve number
= 61
Hydraulic length
W 0 ft
Time of conc. (Tc)
13.20 min
Distribution
W Type II
Shape factor
= 484
Q (cfs)
10.00
WE
WE
4.00
2.00
0.00
960 1080 1200 1320 1440 1560
Time (min)

Hydrograph Report
26
Hydraflow Hydrographs Extension for AutoCADO Civil 3DO 2009 by Autodesk, Inc. v6.066
Tuesday, Apr 27, 2021
Hyd. No. 2
BMP Post -Developed
Hydrograph type =
SCS Runoff
Peak discharge
= 10.53 cfs
Storm frequency =
100 yrs
Time to peak
= 716 min
Time interval =
2 min
Hyd. volume
= 23,221 cuft
Drainage area =
1.120 ac
Curve number
= 89.7
Basin Slope =
0.0 %
Hydraulic length
= 0 ft
Tc method =
USER
Time of conc. (Tc)
= 5.00 min
Total precip. =
7.31 in
Distribution
= Type II
Storm duration =
24 hrs
Shape factor
= 484
Q (cfs)
12.00
10.00
AM
4.00
2.00
I so
k
120 240
Hyd No. 2
BMP Post -Developed
Hyd. No. 2 -- 100 Year
Q (cfs)
12.00
10.00
1M
MI
4.00
2.00
0.00
360 480 600 720 840 960 1080 1200
Time (min)

Hydrograph Report
Hydraflow Hydrographs Extension for AutoCADO Civil 3DO 2009 by Autodesk, Inc. v6.066
Hyd. No. 3
Post Through Pond
Hydrograph type =
Reservoir
Storm frequency =
100 yrs
Time interval =
2 min
Inflow hyd. No. =
2 - BMP Post -Developed
Reservoir name =
BMP Pond
Storage Indication method used.
10.00
. 1e
4.00
2.00
Post Through Pond
Hyd. No. 3 -- 100 Year
120 240 360 480 600
Hyd No. 3 — Hyd No. 2
27
Tuesday, Apr 27, 2021
Peak discharge = 9.082 cfs
Time to peak
= 718 min
Hyd. volume
= 22,785 cuft
Max. Elevation
= 659.29 ft
Max. Storage
= 9,095 cuft
Q (cfs)
12.00
10.00
W
H. el
4.00
2.00
0.00
720 840 960 1080 1200 1320 1440
V Total storage used = 9,095 cult Time (min)

Hydrograph Report
Hydraflow Hydrographs Extension for AutoCADO Civil 3DO 2009 by Autodesk, Inc. v6.066
Hyd. No. 4
Post Developed -
Pond Bypass
Hydrograph type
= SCS Runoff
Storm frequency
- 100 yrs
Time interval
= 2 min
Drainage area
= 0.910 ac
Basin Slope
= 0.0 %
Tc method
= USER
Total precip.
= 7.31 in
Storm duration
= 24 hrs
Q (cfs)
4.00
3.00
2.00
1.00
0.00
0 120 240
Hyd No. 4
28
Tuesday, Apr 27, 2021
Peak discharge = 3.913 cfs
Time to peak
= 722 min
Hyd. volume
= 10,254 cuft
Curve number
= 61.8
Hydraulic length
= 0 ft
Time of conc. (Tc)
= 10.00 min
Distribution
= Type II
Shape factor
= 484
Post Developed - Pond Bypass
Hyd. No. 4 -- 100 Year
360 480 600 720 840
Q (cfs)
4.00
3.00
2.00
1.00
0.00
960 1080 1200 1320 1440 1560
Time (min)

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Triangle Site Design, PLLC
Dollar General Burlington, NC - Storm Drain "C" calculations
Rational Runoff Coefficient "C"
SD Cleanout#101
Drainage &ea (acres; 0
Fromsed Lao
Land Use Description
Acres
% Site
Runoff "C"
"C"
Roofs
0.00
#DIV/O!
0.95
#DIVIOI
Asphalt/Concrete Pavement
0.00
#DIV/O!
0.95
#DIV/0!
Lawn
0.00
#DIV/01
0.3
#DIV/O!
Wooded
0.00
#DIV/O!
0.2
#DIV/O!
Total Area=
0.00
Cumulative "C" =
#
1
iio=
7-09
7.09
Qio=
#DIV/01
Drop Inlet#102
Drainaae Area (acres): 0.20
Proposed Land Uses.
Land Use Description
Acres
% Site
Runoff "C"
"C"
Roofs
0.13
65%
0.95
0.62
Asphalt/Concrete Pavement
0.06
30%
0.95
0.29
Lawn
0.01
5%
0.3
0.02
Wooded
0.00
0%
0.2
0.00
Total Area=
0.20
Cumulative "C• =
0.92
1
i t o=
7.09
Qio=
1.30
Drop Inlet#103
Drainage Area (acres): 0.23
P Land
Land Use Description
Acres
° Site
Runoff "C"
"C'
Roofs
0.12
52%
0.95
0.50
Asphalt/Concrete Pavement
0.08
35%
095
0.33
Lawn
0.03
13%
0.3
0.04
Wooded
0.00
0%
0.2
0.00
Total Area=
0.23
Cumulative "C" =
0.87
1
no=
709
Qio=
1.41

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Triangle Site Design, PLLC
Dollar General Burlington, NC - Storm Drain "C" calculations
Rational Runoff Coefficient "C"
Catch Basin#201
n6gbpaeArea nacres): 0.12
ProvosedLand Uses
Land Use Description
Acres
% Site
Runoff "C"
"C"
Roofs
0.00
0%
0.95
0.00
Asphalt/Concrete Pavement
0.12
100%
0.95
0.95
Lawn
0.00
0%
0.3
0.00
Wooded
0.00
0%
0.2
0.00
Total Area=
0.12
Cumulative "C" =
0.95
1
i1o=
7.09
Q1o=
0.81
Catch Basin#202
Drainage Area (acres): 0.16
Proposed Land Uses.
Land Use Description
Acres
% Site
Runoff "C"
"C"
Roofs
0.00
0%
0.95
0.00
Asphalt/Concrete Pavement
0.16
100%
0.95
0.95
Lawn
0.00
0%
0.3
0.00
Wooded
0.00
0%
0.2
0.00
Total Area=
0.16
Cumulative'V =
0.95
1
iio=
7.09
Q10=
1.08
Catch Basin#203
Drainage Area (acres). 0.24
Pressed[and uses:
Land Use Description
Acres
% Site
Runoff "C"
"C"
Roofs
0.00
0%
0.95
0.00
Asphalt/Concrete Pavement
0.23
96%
0.95
0.91
Lawn
0.01
4%
0.3
0.01
Wooded
0.00
0%
0.2
0.00
Total Area=
0.24
Cumulative "C" =
0.92
1
i1o=
7.09
Q 10=
1.57

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NORTH
AMERICAN
GREEN
CHANNEL ANALYSIS
> > > craw ChannP191
Name
Grass Channel#1
Discharge
1.13
Channel Slope
0.0158
Channel Bottom Width
1
Left Side Slope
2
Right Side Slope
2
Low Flow Liner
Retardence Class
C 6-12 in
Vegetation Type
None
Vegetation Density
Good 65-79%
Soil Type
Clay Loam (CL)
DS75
North American Green
5401 St. Wendel -Cynthia na Rd.
Poseyville, Indiana 47633
Tel. [phone]
> Fax [phone]
www.nagreen.com
ECM DS v7.0
Normal
Permissible
Calculated
Safety
Staple
Phase
Reach
Discharge
Velocity
Mannings N
Remarks
Depth
Shear Stress
Shear Stress
Factor
Pattern
DS75
Straight 1.13 cfs 1.92 ft/s
0.35 ft
0.036 1.6 Ibs/ft2
0.34 Ibs/ft2
4.69
STABLE D
Unvegetated
Underlying
Straight 1.13 cfs 1.92 ft/s
0.35 ft
0.036 1.74 Ibs/ft2
0.23 Ibs/ft2
7.69
STABLE D
Substrate

Triangle Slte Design, PLLC
Dollar General Burlington, NC - Grass Channel "C' calculations
Rational Runoff Coefficient "C"
SD Cleanout*101
oralnaae Area (WMS). 0.53
ft n
Land Use Descrivt/on
Acres
% Site
Runoff "C"
"C"
Roofs
0.00
0%
0.95
0.00
Asphalt/Concrete Pavement
0.00
0%
0.95
0.00
Lawn
0.53
100%
0.3
0.30
Wooded
0.00
0%
0.2
0.00
Total Area=
0.53
Cumulative "C" =
0 30
1
ho=
7.09
Q1o=
1.13

EROSION CONTROL CALCULATIONS

EROSION CONTROL CALCS (RIP -RAP CALCULATIONS)
Project Information
Project Name:
Project #:
Designed by:
Revised by:
Checked by:
R inn — R o_F_A� rQn_#1
Dollar General
Pipe Diameter
Pipe Slope
Manning's number
Flow
Velocity
Date:
Date:
Date:
d= 15
s= 1.89
n= 0.013
Q= 2 cfs
V = 1.63 ft/s
Dissipator Dimensions *
Zone =
Stone Filling
Class =
Entry Width ( 3
X Do ) _
Length ( 6
X Do ) _
Width (La
+ Do) _
Min. Thickness
=
Min. Stone Diameter=
* All units are in feet
** Dissipator pad designed for full flow of pipe
i
1
B
2
3.8 ft
7.5 ft
8.8 ft
22 inches
6 inches
7.5
* All units are in feet
** Dissipator pad designed for full f
RIP -RAP -Burlington 4/27/2021 Page 1 of 4

Rip —Rap Apron#2
Pipe Diameter
Pipe Slope
Manning's number
Flow
Velocity
d= 15
s= 4.14
n= 0.013
Q= 2.71 cfs
V - 4.12 ft/s
Dissipator Dimensions *
Zone =
Stone Filling
Class = B
Entry Width ( 3
X Do )
Length ( 6
X Do )
Width (La
+ Da) _
Min. Thickness =
Min. Stone Diameter=
I
3.8 ft
7.5 ft
8.8 ff
22 inches
6 inches
7.5
* All units are in feet
** Dissipator pad designed for full f
RIP -RAP -Burlington 4/27/2021 Page 2 of 4

Rip —Rap Apron#3
Pipe Diameter
Pipe Slope
Manning's number
Flow
Velocity
d= 15
s= 0.56
n= 0.013
4 Q= 4 3.46 cfs
4 V = 4.30 ft/s
Dissipator Dimensions *
Zone =
Stone Filling
Class =
Entry Width ( 3
X Do ) _
Length ( 6
X Do ) _
Width (La
+ Do) _
Min. Thickness
=
Min. Stone Diameter=
r
'i
A
2
3.8 ft
7.5 ft
8.8 ft
22 inches
6 inches
7.5
8.8
* All units are in feet
** Dissipator pad designed for full f
RIP -RAP -Burlington 4/27/2021 Page 3 of 4

Rip-Rap_Apron#4
Pipe Diameter
Pipe Slope
Manning's number
Flow
Velocity
d= 15 in
s= 2.27
n= 0.013
4 Q=1 .786 cfs
4 V .= 1.46 ft/s
Dissipator Dimensions *
Zone =
Stone Filling
Class = B
Entry Width ( 3
X AO )
Length ( 6
X Ao )
Width (La
+ Ao)
Min. Thickness
=
Min. Stone Diameter=
2
3.8 ft
7.5 ft
8.8 ft
22 inches
6 inches
7.5
* All units are in feet
** Dissipator pad designed for full f
RIP -RAP -Burlington 4/27/2021 Page 4 of 4

EROSION CONTROL CALCS (SKIMMER BASINS)
Project Information
Project Name:
Dollar General
Project #: _
Designed by:
RG Date:
Revised by:
Date:
_
Checked by:
Date:
Skimmer Basin #1
Drainage Area
Total, AT= 1.56 AC
Disturbed, Ao= 156 AC
25-year Runoff (Qte)
C = 0.50
T. = 5.00 min
I, = 774 inthr
Q, = 6.0 cfs
Surface Area Required
SA = 325sf x Q25
SA = 1,962 sf
Volume Required
VR = 1800 d/Ac x AD
VR = 2,808 cf
Sediment Trap Dimensions
L = 75 ft (Spillway Length)
W = 30 ft (Spillway Width)
D = 2.0 It (Depth of Storage)
Side Slopes = 2 :1
Lmp =
83 ft
Lam=
67 ft WE3
Wbd
WW=
38 ft
La„=
WW=
22 ft
L/W Ratio=
2.5 :1 (must be 2:1 to 6:1)
Elevations Description
Elevation
Top of Berl
361.00 (allow lit freeboard above spillway flow height)
Emergency Spillway
359.50
Sediment Storage
359.00
Cleanout Mark
358.00 (half of storage height)
Bottom
357.00
Provided SAP=
2,250 sf > 1,962
Vp =
3,724.0 cf > 2.808
Emergency Spillway - 25 Year Storm I, =
7.74 in/hr
Q25 =
6.04 cfs
h =
0.5 ft
C„, =
3
Lw=
10 ft

Calculate Skimmer Size
Basin Volume in Cubic Feet 3.724 Cu.Ft Skimmer Size 1.5 Inch
Days to Drain' 3 Days Orifice Radius 0.6 Inch[es]
Orifice Diameter 1.3 Inch[es]
'In NC assume 3 days to drain
Estimate Volume of Basin Length Width
Top of water surface in feet 75 30 Feet VOLUME 3724 Cu. Ft.
Bottom dimensions in feet 67 221 Feet
Depth in feet 2 Feet

EROSION CONTROL CALCS (SKIMMER BASINS)
Project Information
Project Name:
Project #:
Designed by:
Revised by:
Checked by:
Anti -Flotation Device
Dollar General
4' x 4' Outlet Structure
Area:
16.0
sf
Top of Basin Elev.:
359.0
Bottom of Basin Elev.:
357.0
Volume:
32.0
cf
Weight:
1997
Ibs
Factor of Safety
1.20
WT Req'd of Anti -Flotation Device:
2,396
Ibs
Volume of Concrete Req'd:
16.0
cf
Volume Provided:
69.5
cf
Date:
Date:
Date:
(Water Displaced - Top of Pond to Bottom of Pond)
(Unit WT of Concrete = 150 pcf)
(4'x4' riser x 2.0' = 32cf, 5'x5' footing x 1.5'=37.5cf)

4/27/2021
ECMDS 7.0
NORTH
North American Green
ANIERICAN
5401 St. Wendel-Cynthiana Rd.
Poseyville, Indiana 47633
GREEN
Tel. [phone]
> Fax [phone]
www.nagreen.com
ECMDS v7.0
CHANNEL ANALYSIS
> > > Temparary Ditch#1
Name Temporary Ditch#1
Discharge 2.5
Channel Slope 0.0179
Channel Bottom Width 1
Left Side Slope 2
Right Side Slope 2
Low Flow Liner
Retardence Class C 6-12 in
Vegetation Type
None
Vegetation Density None
Soil Type
Clay Loam (CL)
DS75
Phase
Reach
Discharge
Velocity
Normal
Mannings N
Permissible
Calculated
Safety
Remarks
I
Staple
I
Depth
Shear Stress
Shear Stress
Factor
Pattern
DS75
Straight 2.5 cfs 2.59 ft/s
0.49 ft
0.035 1.6 Ibs/ft2
0.55 Ibs/ft2
2.93
STABLE D
Unvegetated
Underlying
Straight 2.5 cfs 2.59 ft/s
0.49 ft
0.035 1.74 Ibs/ft2
0.34 Ibs/ft2
5.15
STABLE D
Substrate
https://ecmds.com/projecttl39235/channel-analysis/202960/show 1/1

4/27/2021
ECMDS 7.0
NORTH
AMERICAN
GREEN'
CHANNEL ANALYSIS
> > > Temporary Ditch#2
North American Green
5401 St. Wend el -Cynthia na Rd.
Poseyville, Indiana 47633
Tel. [phone]
> Fax [phone]
www.nagreen.com
ECMDS v7.0
Name
Temporary Ditch#2
Discharge
2.5
Channel Slope
0.0217
Channel Bottom Width 1
Left Side Slope
2
Right Side Slope
2
Low Flow Liner
Retardence Class C 6-12 in
Vegetation Type
None
Vegetation Density None
Soil Type
Clay Loam (CL)
DS75
Normal
Permissible
Calculated
Safety
Staple
Phase
Reach
Discharge
Velocity
Mannings N
Remarks
Depth
Shear Stress
Shear Stress
Factor
Pattern
DS75
Straight 2.5 cfs 2.82 ft/s
0.46 ft
0.034 1.6 Ibs/ft2
0.62 Ibs/ft2
2.57
STABLE D
Unvegetated
Underlying
Straight 2.5 cfs 2.82 ft/s
0.46 ft
0.034 1.74 Ibs/ft2
0.39 Ibs/ft2
4.45
STABLE D
Substrate
https://ecmds.com/project/l 39235/channel-analysis/202960/show# 1 /1