SW5211201_Design Calculations_20220221

Storm Wafer & Erosion Control
Design Calculations
February 21, 2022
Dollar General Store
W. NC Highway 97
Middlesex, NC
Nash County
Prepared for:
Glandon Forest Equity, LLC
3825 Barrett Drive, Suite100
Raleigh, NC 27609
[phone]
Prepared by:
Bowman North Carolina, Ltd.
(Formerly Triangle Site Design, PLLC)
4004 Barrett Drive, Suite 101
Raleigh, NC 27609
[phone]
Firm#F-1445
TRIANGLE
S I T E DES 1 G N
a Bowman company

TABLE OF CONTENTS
OVERVIEW
STORMWATER NARRATIVE
FIGURES
SOILS SURVEY & SOIL INFORMATION
USGS TOPOGRAPHIC MAP
FEMA FIRM MAP
SURFACE WATER CLASSIFICATIONS
HUC
NOAA POINT PRECIPATION FREQUENCY ESTIMATES
WATER QUANTITY/QUALITY
WET POND
DESIGN SUPPLEMENT
NUTRIENT CALCULATIONS
CN VALUES
PRE -DEVELOPMENT HYDRCGRAFHS
POST -DEVELOPMENT HYDROGRAPHS
TIME VS. VOLUME (STORAGE)
TIME VS. ELEVATION (STAGE)
ELEVATION -VOLUME -FLOW SUMMARY
POND OUTLET/STRUCTURE SUMMARY
EROSION CONTROL CALCULATIONS
RIP -RAP APRON
SKIMMER BASIN
ANTI -FLOTATION CALCULATIONS
TEMPORARY DIVERSION DITCH

OVERVIEW
Background
This report contains the storm water and erosion control calculations for the proposed
Dollar General retail site. The project site is located at W. NC Highway 97 in Middlesex,
Nash County near the intersection with NC Hwy 97 and NC Hwy 231 is currently a
residential development. The proposed project site consists of 2.00 acres and
approximately 1.77 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 38,890sf (0.89ac -
44.59% impervious).
The proposed Dollar General parcel is not located within a FEMA designated flood zone as
shown on FEMA FIRM Panel 3720274600J with an effective date of 11/3/04. 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 Neuse river basin.
The site must also meet Neuse Watershed Nutrient requirements. The TN export for the
pre —developed conditions is 4.00 Ibs/yr which is a rate of 2.00 Ibs/ac/yr for the
project area. The increase in impervious area will result in a TN export rate of 20.20
Ibs/yr which is at a rate of 10.10 Ibs/ac/yr. Since the rate is above the
10.Olbs/ac/yr threshold, a stormwater BMP system will be required to reduce the TN
export from the site. A wet pond is proposed for the project to capture the runoff
from the developed areas of the property and treat it for water quality and water
quantity control. The TN export rate for the site after the BMP will be 14.56 Ibs/yr
which is a rate of 7.28 Ibs/ac/yr.
The proposed storm water
management facility
(wet pond) 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 pond. The pond
is designed to detain a
drainage area of
1.23ac with an impervious
area of 0.90ac. The
balance of the site is
open space and
will by—pass the proposed
pond.

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 Norfolk, Georgeville, and Faceville soils are present
on the site.
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

35° 51' 36' N
35° 51' 31' N
Hydrologic Soil Group —Nash County, North Carolina
a Map Scale: 1:791 If pUed on A portralt (8.5' x 11') st>eet. a
N 0 id 2C} 47
A 0
� 35 70 140 210
Map prDWJOn: Web Menator CaT'ff 000rtrates: WGS84 Edge bLs: UM Zone 17N WGS84
l d). Natural Resources Web Soil Survey 9/20/2021
Conservation Service National Cooperative Soil Survey Page 1 of 4
35° 51' 35' N
35° 51' 31' N

N 0
NC64
O O
N
N N
Y
m
U
O
a)
tm
mo a)
U
m
a�
^L
m
v
N
2
1
O U
3Co
O a
m
T o
C U N N
Q
(6
Z
O V O
L N� E
v
m
U
O
N C
a) `O
d
j
E
(n
N '~ N
_
Q
N
C Y a)
Z
O
C U O
—0O
O
N L N •3
U
E
N
.N .0 O
O
S.
a3
N
N
(9
.L.. a 7 6
N
U
O
C
O
U
O
N N
w a)
a)
N
C
E m 3
L
N
Z
a) (�
0 L O d d
Z
O O
N
N
'L 7 0
L N
.n
10
l0
N
O
a)
L N
N
O
Q
_
O
(a/ N
U m O N
L
O W
N
N C 2 o
S C S �p
o
D
L
�p
10
2
C N 0.0
O
0
L
N E N L
la
U O
_Q
2 0 O C O
a)
C
C
z o
N
U
l`
Gl
O N Q
Q N N
>`
>
y 0 0 w
_ C>
O
C
7 U
N
T N o a)
U
.L..
>`
O)
Q
N
O
Q E
>+
Z
c
a)
d
C 2 O L
O
a)
Z U .0 a) m
C
NO
a
N
a) m E d
Q
E
C
O a7 a
a
U
a
N
7 N U 0 jn
O O n�
�
v
N
a
N
N L N
d E
7
N
O
N
L
3
rL
Q
U
m
m
E
co" E U
Qoo�
O J
my
N Q C O
co�Q$c
li
la
Z
d
m
.J O
a)o_n
'''
W
E Cl L .L..
N
Z O
N Q N fa •c
dy
N a0.
fa
d
aNi
N
O" a .0
N
C N
-C
T..
L `J ` 10
L� fa U
OW, (a
.y C
m Ao
L1J
N
. m
'�
O Ol N
w0 Q Q
y
O
co
C la N N
a� E
O C
T
M CO
w
w 3 1p
7 .�
Q
�N,
UI
o Co
G N E
p,
` m
l0
E
7
N�
E m U
O O U O
O` >
7 0
m 0
m
a)
•C
01 C
a a)
N_ C
N
N N
N
`
7 N O
N U C N
Q .a, al
Q O
N
7 T
(n o
_ ?
E
_ O
jp ;5
N
�,-
O Q C
01
F-
N la
W E U N
N
a E
co U
.m
U
(7�
Q Q m
=
L .�
H O
0 7
to to
O �!%
c4
�vQ
la lf7
o N
L p£—
F- U .— N
T
N
2
0
4) 'o
2�
w
�
a,
o
u) Q
0
co N
N C
N
L
a O
U
C U
(Ta
L
C
O m
la
E
m f
a
m
f0
o dO
Z
U ()
O
m
Z (n O
d' O
m 16
Jo <
Q
=
0
9
7
Z
W
� t
�
lL
0 a
C
O
Y
�.
V
F
* F
m
W
J
m
m
a
m
Q
o
co
N
a)
OC
m
~O
C
a
C
N
C
O
O
_0
`O
v L
n
a Q
a)
c
a
ImQ
C
o O
a m m
C)
e o
z mQ <
m m
e
o
G
z IL a)
a m
m
n
.
C
}
w
N
wN�
N
I�1
y
l
t N
V
Q
C
0 C
N '=
m
d'
_Z
m y
7 N
w C
l6 O
ZU

Hydrologic Soil Group —Nash County, North Carolina
Hydrologic Soil Group
Map unit symbol Map unit name Rating Acres in AOI Percent of AOI
NrB Norfolk, Georgeville, A 2.3 100.0%
and Faceville soils, 2
to 8 percent slopes
Totals for Area of Interest 2.3 100.0%
Description
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 Web Soil Survey 9/20/2021
;'� Conservation Service National Cooperative Soil Survey Page 3 of 4

mm
Q
Q 12 C N
y0
U-
m m
m a _
m m
m i
H L L E
m
a >
¢
o
m. m
= 3 3
s m
N J
¢
as >
> o
m b
.2
°° O
w
a v O X 7
a N W
m
mm
U U m 0
O d a
-j y W s
a N y
w
C C O
m m O
WCm
N y-0
m o
c 2
= 'aU00p
m Zw
m� W O
C C
C
U LL r N Y
U-
m m
Q m
U 3 3
OT
= r L 3
L y
m
m m
m O C m m
+y N m
N `1 m
i
t_
� W
LL
OJ a
QOQ I�Q�J
W Q
it 0
W
W O
IL
N
m
O
_O
LL
m
c
O
m
Z
N
U
X
d
'
t
a
in
r m
N
O
2
o
li
E_
a m m
C E C
O
m
Y
� O J
C y
m
.2
CLL
`m
m LL
3 w ti > > Fi
m m
L LL
E
m
>°
m O
o U y W a m y'
U
c O
m
U m
10 m a c 1
O ~_
d m
CL
( gy(pp t
is
O
O
0
C
O
� N m LL O ° m
4i
p3 b0
m
y a
O
m m
m
m >
O f0 m N E m N
U COO U
a
d 2
�
Iy
�
m
~O
Er
W
w U
x
CC)
LL
2
r
o
F
�
� f
4 �`
1
�
(0 2-
2�
IL
Q m
N Y
E
C
y
mCL
m o c
O
CD
3 m
ECD
aL.
~ °c v
.0
o o m E a
m
-0a
y a O
O E
m m m
t a m m
O r L
N VCL ym�
a Y m 7
m
L
m >
C
O O
E
Y L y
a
w m 9
T W a p °
LL a >`
O a C m
Y - C 9
L m m E m
OE @ p
Q W
C y 0
m m W
' c E
:O d 0 :-•
m m E a
° N U> U
m p
�0 CD
O
-0. a
a a LL
m yL
>>
QNL �>
0
E E
a) -y
0 0. % m CO
0 a
>
u!
0 CL +'.I y o
m
�0 C C
m m a
'pp E
o z° =
y 7 .�
''M
Q m
wo'a
C V "m0
2 C'JE
° m O E a
CD
«2m-"
LL
c L
y
LL c
m 0 m
a U
m C
tom
�
°3NEma''
oammo
F a m
m 0 E
L
C= m ° m a
m a j CD
y
m
E
LL C m
m
J
LU
v e '�°
M j CD C Z a
im�pp C m Q
Z
a 0 m a
a 20 L m y
a y y c m
Q
Eye 2
z `o mf'i~ E
E 0 CLCL
d
Q
N m=
L.mL
m L y m N V
L 7 m m E m
y E .2 E O
L m Opp C m
H a H m
H m
O H N m lLL
Z
fV
In
M
3
M
0
Y
Q
LL Q
1 O N
0
0
0
C.
C
0
0
LO
0
LO
N
r

� d
. �
¥
z *
� CD �
% n \ !WC
_ Cif
a j �I
u 9$H
, \\
:t}ym
IRON 0 y
wite �� I
���
E
- -
-- ■
ƒ
0ƒ
f 0
uu
/
k
0 0
o
\
\2
E§
k
§
)
2
%��&
d
J
a
2
2
.
� _
..�
J
p
.
�
E
0
..
•
\
,�
/
&/
$
°
2
.
k
}
ƒ
` ~
0
\
\
\ )
E
ƒ
/
W
©vm

r
u

9/20/21, 2:05 PM Precipitation Frequency Data Server
NOAA Atlas 14, Volume 2, Version 3
Location name: Middlesex, North Carolina, USA' i
Latitude: 35.8606°, Longitude:-78.1783°
l Elevation: 272.62 fr' €
'source: ESRI Maps
source: USGS
POINT PRECIPITATION FREQUENCY ESTIMATES
G M Bonnin, D Martin, B Lin, T Parzybok, 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)
Quration
�00 10
25 50 100 200 500 1000
5�r1in
F-O-.4-0-171
0.461
0.518
0.592
0.663
0.725
0.780
0.831
0.888
0.946
(0 365-0.442
0 421-0 15 5
0.72-0.G67
0-539-0 643
0.601-0.728
0.655-0.794
01700.0:853
0:741-0.91❑
0.786-0 975
(0 829-1.04
1.06
-71
10�rlin
0.584-0.706
.673-0908
0.756.0909
0. 63-1 4
0.958--1116
1.041626
1. 1� 3G
1. 831�44
1 2441154
1 3141.64
0.801
15{rlin
0 729 0883
0. 46-21602
0.957---515
1 09--1031
1 21-31447
1 3241660
1.41--1771
(1.4861682
1 57 1.94
(1.64-2.06
30�rlin
021)
8
1001
(117---1.40]
(136-1963]
(1.5874
90}
1 0-- (217}
(1. 92041]
: (25-20)
2 (231-83
2.493.09
(2653 .33)
3
6
60�»in
1
4
1
2
1 25-1.51
1 47---1.76)
(1.7-0209
(2.Ofi 24E
2 39 2
6989) (2.327)
(2.J73S2]
3,246398}
:4 37 43
3. 8 486
1.60
1.88
2.26
2.72
3.24
3.74
4.21
4.72
5.38
6.02
2-hr
1 44-1.T7
1 71-2.06)
2.05.2.49)
2.48-2.99
(2 91-3 55
(3.35A.10)
[3.75-4.61
{A.17-5 17
4 715.90
522.6.62
3-hr
1.69
(1 53-1.88)
1.99
(1.81-2.21)
2.41
(2:19-2.67)
2.92
(2.64.3.22
3.51
(3 15-3.86)
4.08
1 (3.85.4 49)
4.64
1 (4.12-5 11)
5.25
6.08
1 (5.29-6.68)
6.89
(5:92-7.60)
6-hr
B
1.850325
(2. 8 2964]
2.6383.19)
3 83086}
3.81-464
4.425 41
5 01 fi518]
{5.6347101
6.47 8615]
7. -9032
2.
12-hr
2_63)
a
(2.58 3109
3. 2 3.76
78-4.57
4.575.53
5. 3-G 49
G.08--T481
6.87.8.53
7. 5210.0
8.99-161 5
24-hr
8.28
2 63 3305
3. 8 3?7A
4 05-0 72
4.757-5.5G
5.79 6978
6.52-7.82
7 8894
{8.464 0 2
(9.82-12.0)
1(10 9- 3.6
2�ay
3.G43753)
: 3a-4 26
(4,65 5 39)
1 (5 44-6.3?
7 6.55-67
7.4718.8t}
8 44 0.0
9.46 11 4
(10 9-13 4]
12 13 5 1
3�ay
(3 24 3.74
3.68
(390--4.5a)
4.42
4.91?5.fi6
5.54
-(6.62]
(5.7
6.45
(6.8543.7.99
7.75
7, 0 9913
8.82
(8 9 6-2-7 0.4)
9.97
$ 80 181.i
11.2
(11 3-13 71
12.9
4.1
(1214-15.4)
14.4
4�ay
3 43-3.94
4,13-4 74
5.17-5 94)
( 6.00.6.91
(7 17.8.301
8.12-9.47
9 11-10 7Y
11 6-14.0
12 8-15 7
4.28
5.13
6.35
7.34
8.74
9.89
11.1
12.4
14.2
15.6
play
(4.00 4:5B)
1 (A.80.5.49)
(5.93.6.80)
1 (6.85.7.86)
j (8.12.9 36)
1 (9.13-10.8)
1 [102-11.9)
1 (12 8-15.3)
(14 0-17 0)
4.89
5.83
7.12
8.15
1 9.59
10.8
12.0
13.2
15.0
16.5
10�tay
4.58 5.21
5.47-8.72
5.67-7 53
7 63 H.6d
5 84-10.2
9:98=11:5
11 1-12.8)
(12 1-14.2
13 7-16.2
(14 9-17 8
20{lay
619 6.98
7, 5�8.29
8.8139.94
9 97 111 3
11 6-13 1
12.8-14.5
14 1-161
1514-17 8
1.7
17.18-0 1
1825-21 9
8.16
9.64
11.4
12.8
14.6
16.1
17.5
19.0
21.1
22.6
30�ay
7.71-8.64
9.11-10.2
10 8-12 1
12 0-13.5
13 7-15.5
15.0.17-0
16 4-18.6
17 7-20.3
19 4-22.5
(20.8.24.3
45�1ay
3.20:5]
4-7
4-28
(9.84.1❑.9)
(11 6-12.9)
[1314- 5 0)
(1419- 6.6)
(1618-18 8)
[18
(1927.22 3)
[21�2 24.0)
(23?6.26.4)
(24 2)
60�1ay
11 B2 3 1
(13.9-15 3)
1519--187 6
i 715- 9 4
1926- 1.8
L.2-23.b
2274-25.4
24 2527 2
2629 29 fi
(272 -31 4]
Precipitation frequency (PF) estimates in this table are based on frequency analysis of partial duration series (PDS)
Numbats in parenthesis are PF estimates at lower and upper bounds of the 90% confidence interval The probability that precipitation frequency estimates (fora
given duration and average reCUTrenaL irderval] will be grealer than the upper bound (or less than the lower bound) is 5%. Estimates at upper bounds are not
checked against provable rreximum pre oipitatton (PMP) estimates and may be higher Than currently valid PMF'values.
Please refer to NOAA Atlas 14 document for more information
Back to Tap
PF graphical
hftps://hdsc.nws.noaa.gov/hdsc/pfds/pfds_printpage.html?lat=35.8606&Ion=-78.1783&data=depth&units=english&series=pds 1/4

WATER QUALITY/QUANTITY

Nitrogen Calculations (on -site areas)
Item
Proposed Site Information
On -Site Area
Off -Site Area
Total
1
Total ro'ed acres a
2.00
0.00
2.00
2
Total proposed impervious
area
0.89
0.00
0.89
3
Existin impervious area
0.08
0
0.08
4
New impervious area
Item 2 Item 31
0.81
0
0.81
5
Permanent y protecte
undisturbed open space
0
0
0
6
Permanently protecte
mana ed open space
1.11
0.00
1.11
Exjstlhq Conditions LoadI(On-site areas
Type of Land Cover
Area acres
TN export/coeffrc/ent
lbs/a r)
TN export from use
(lbs/yr)
Permanently protected
undisturbed open space
0
0.6
0.00
Permanently protected
managed open sace
1.920
1.2
2.30
Impervious surfaces
0.08
21.2
1.70
Total
2.000
Item 7
_
4.00
Item 8
Nitrogen Loading Rate (Ibs/ac/yr)
2.00
Proposed Development Areas On -Site areas
TN export/coeliicient
TV export from use
T e of Land Cover
Area (acres)
lbs act r
Ibs/ r
ermanen y pro e e
undisturbed open space
Item 5
0
0.6
0.00
ermanen y pro e e
managed open space*
Item 6
1.110
1.2
1.33
Impervious surfaces
Item 4
0.890
21.2
18.87
Total
2.000
20.20
Item 7
Item 8*
Nitrogen Loading Rate (Ibs/ac/yr)
10.10
Post -Development Load/no after Offset falvments
Item
Description
Pre -Developed +Post -
Developed Loading
8
Total TN export (lb/yr)
14.56
Post -De ve% ment Loadin after Offset Payments
Item
Description
Nitrogen Loading Rate
Ibs ac r
9
Post -Developed TN Load
10
Nitrogen load offset by
3.68
payments Item 9 - 3.6
Amount of Offset (buy -down loading rate x apportioned site area)(lbs/yr): 7.36
30-Year Offset Amount (Pounds of Nitrogen x 30 Years)(lbs): 220.72
NCEEP Offset Payment Rate ($/Ib) $24.77
NCEEP Offset Payment Amount• $5,467.14

N
C
O
V
O
7
O r,
O
O
N
O
O r`
O N
O
O"
O O
ID
N
fM
M
a o g o rii oM
E o In o 0 0
w
a
z
H
v v v
c c c
n c c 0c
m
E o rn o
o 0 C.
X
N
N
a
a+
c
C) N N
U
A
v v
c c
0 0
a a
v v
0 0
v
o
O O
N N
.-1 N
N O O O
a n o pMi rn
o 0 0 o Ce
C1
a
y
V
O O
N
lJ
O U
d O
'^
m N
'�
m
O
0
L
c
m y
n
O1
c c_
ro v
n
m
n
m
o, toy
c
c
E m
U UN
v o
E
v N
v o
oYn
c�
a
U
v v a
n d
omto
_�
v v
v
��
J W
v
r_co
N
N>
N m
r_co
—
N>
v f0
aJ ❑
�
O VI
� 2
0 uj
� D_
v v
E
n
nL°
y
—Lon
nM
O�
�w
O
cn.>,
U
—��,
�=i1
O
d C
m
0 T
C m
=O T
0 f O
r_
E tni
v 3
E m
3
Q)
lb
a
E>
a
E.">_
o a
n
LQ
v
0
N

SUPPLEMENT-EZ COVER PAGE
i c- LOAOEG
PROJECT INFORMATION
1
Project Name
Dollar General
2
Project Area (ac)
2.00
3
Coastal Wetland Area ac
-
4
Surface Water Area ac
-
5
Is this project High or Low Density?
High
6
Does this project use an off -site SCM?
No
COMPLIANCE WITH 02H .1Q63(4j
7
Width of vegetated setbacks provided feet _
Will the vegetated setback remain vegetated?
N/A
N/A
8
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 Stri 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 1
Bayfilter
0
1.26 1
Filterra
0
FORMS LOADED
DESIGNER CERTIFICATION
27
Name and Title:
Matt Lowder, PE
28
Organization:
Bowman North Carolina, Ltd. '
29
Street address:
4004 Barrett Drive, Suite 101
30
City, State, Zip:
Raleigh. NC 27609 j
31
_
Phone numbers : v— —
Email:
919-553-6570.
� [e-mail]
[e-mail]
Certification Statement:
I certify, under penalty of law that this Supplement FZ form and all supporting information were prepared under my direction or supervision; thatthe
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.
ARO
SERE. �
24434
46
fry lrr rrlriltltt\1
Seal
ionaiure df Designer .
Date

DRAINAGE AREAS
1
Is this a high density project?
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
Tyee of SCM
-
Wet Pond
5
Total draina a area (sq ft
87223 sf
53402
6
Onsite drainage area (sq ft
87223 sf
53402
7
Offsite drainage area sq
8
Total BUA in ro'ect s ft
38890 sf
38890 sf
9
New BUA on subdivided lots (subject to permitting)
(sq ft
10permitting)
New BUA not on subdivided lots (subject to
(s
11
Offsite BUA (sq ft
12
Breakdown of new BUA not on subdivided lots:
Parking (sq ft
Sidewalk (sq ft
1720 sf
1720 sf
Roof (sq ft
10640 sf
10640 sf
Roadway s ft
26530 sf
26530 sf
Future �sq ft)
Other, please specify in the comment box
below (sq ft
13
New infiltrating permeable pavement on
subdivided lots (sq ft
14
New infiltrating permeable pavement not on
subdivided lots (sq ft
15permitting)
Existing BUA that will remain (not subject to
s ft
16
Existing BUA that is already permitted (sq ft
17
Existing BUA that will be removed (sq ft
18
Percent BUA
45%
73%
19
Design storm inches
1.0 in
20
Desi n volume of SCM cu ft
3139 cf
21
Calculation method for design volume
Simple Method
ADDITIONAL INFORMATION
22
Please use this space to provide any additional information about the
drainage area(s):

WET POND
area number
GENERAL MDC FROM 02H .1050
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
Does the SCM have retaining walls, gabion walls or other
6
engineered side slopes?
No
Are the inlets, outlets, and receiving stream protected from erosion
7 10- ear storm)?
Yes
8 Is there an overflow or bypass for inflow volume in excess of the
design volume?
Yes
What is the method for dewaterin the SCM for maintenance?
Pum referred)
If a licable, will the SCM be cleaned out after construction?
A
Yes
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 (10)?
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
knAlrO1i-A!iImlL:..I�qLpri ce
18 SWng method used
SAIDA
19 Has a stage/storage table been provided in the calculations?
Yes
20 Elevation of the excavated main pool depth (bottom of sediment
removal) (fmsl
252.00
21 Elevation of the main pool bottom (top of sediment removal) (fmsl)
253.00
22 Elevation of the bottom of the vegetated shelf (fmsl)
258.50
23 Elevation of the permanent pW sl
259.00
24 Elevation of the top of the vegetated shelf (fmsl)
259.50
25 Elevation of the temporary pool (fmsl)
259.90
26 Surface area of the main permanent pool (square feet
2205
27 Volume of the main permanent pool (cubic feet)
5821 cf
28 Average depth of the main pool (feet)
3.41 ft
29 Average depth euation used
Equation 3
30 If using equation 3, main pool perimeter (feet)
188.0 ft
31 If using equation 3, width of submerged ve . shelf (feet)
3.0 ft
32 Volume of the foreba (cubic feet)
1104 cf
33 Is this 15-20% of the volume in the main,pool?
Yes
34 Clean -out depth for foreba inches
24 in
35 Design volume of SCM cu ft
3139 cf
36 Is the outlet an orifice or a weir?
Orifice
37 If orifice, orifice diameter inches
1.00 in
38 If weir, weir height inches
39 If weir, weir length inches
40 Drawdown time for the temporary pool (days)
2.02
41 Are the inlet(s) and outlet located in a manner that avoids short-
circuitin
Yes
42 Are berms or baffles provided to improve the flowpath?
Yes
43 Depth of forebay at entrance (inches)
36 in
44 Depth of forebay at exit (inches)
30 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:V)
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
H brid Bermuda
54 Hasa lantin Ian been rovided for the ve etated shelf?
Yes
ADDITIONAL INFORMATiON
Please use this space to provide any additional information about
55 the wet pond(s):
Wet Pond 1 1:47 PM 10/13/2021

W+
z• 4..
oupvnJ 4!-N 'zerolPD!Mle
s
I
� rg a ca • '-
a will��N
E �,r 3g f6 3yE
I
I J �.
r
r:
�+ f
_ !� r r
rI�-
i
0
I
8
N
xz
o
N
E
w o
U
1r a 3� 6 EQ S a 6yg
a�G
k�
g�
5
E
a 9
q

J _ = ¢ G O
L7 a = �^ AfurwO 4aDN � E
N K °uU—J 4 -N '--IPPIN �. a
3 z o 16 A-451H ON A W h i
� �8�
�710a
alit X
AIRP
F�� ii § E Ey€� 1FIgLI • F¢
gIR@®e 3 l fix `pE .3ij
• . • • .. • • k c tl tl A f Y e ! E ! • R A Y
I
I
I
r
II
I
I,
I�
l
I
1
I
t
I
I
I
I
I
f
I
1
V
k
O
Z
o
Z
I
¢
j�
F �9 i tl �iF �� � @ � � �A�� � g� ! �•tl i �R ��� � tl '��� tl i
SS;i Fxg l
R k - Hil
till
eF
pp k�
4I i
ppg � Fk �rr
CD
Z Fk @CRC B
1pg
W . e ..
$ i!
CD HIM sill
2
■g
p p
� i.i p
ZfA
oz�y0���•
V
zg�
C5
B@zF�3
3
� Fk W ■Fp[ Q
N
!p p
0 � �8
e0p[
@@
O�
i.
90 i
S}k
�
Je�Ra�tlFl�
I
R i
TW[YI mil - r- MAY• nY
44
I
Rr ,
I

6
AVD03 4"WI `� E
-11=3 4WN '--IPP111 S 8
U Ae 461H DN 'MVIA
§
5 ye � 0
IaRM,�a J
R �e 09 'fal 1 gFE 109 H 'oi a 'i8 A @ e
I
Zs
�
Za
i
e
�cl
U
'I
� ag
f�
e E ix� !•
p � �
evil
ig
R E ■
yy iEi
�ilFieig�i
r
Z 901��gEgEgoga
1 i
w
>! W
B
• 9i
A 2
■�
p
�
��g
U
W
g
N
66 gg
O
EBg@
p
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
r
Jlr
1
Nil ��
mr
i
t
4 4 �
I R
1

Triangle Site Design, PLLC
Curve Number Calculation (CN)
Pre -Developed Conditions (Overall Site)
Drainage Area (acres): 2.00
Existing Soil Groups:
Soil Grown Map Symbol Soil Description Acres Percent of DA
A NrB Norfolk, Georgeville, and Faceville 2.00 100%
Proposed Land Uses
Land Use Description Existing Soil Group Acres Curve # Weighted CN
Wooded - Good A 1.92 54 51.8
Impervious A 0.08 98 3.9
Cumulative Curve # = 55.8

Triangle Site Design, PLLC
Curve Number Calculation (CN)
Post -Developed Conditions (Wet Pond)
Drainage Area (acres): 1.23
Existing Soil Gros:
Soil Grouo Man Symbol Soil Description Acres Percent of DA
A NrB Norfolk, Georgeville, and Faceville 1.23 100%
Proposed Land Uses:
Land Use Description Existing Soil Group Acres Curve # W_ _erghted CN
Wooded - Good A 0.00 54 0.0
Open Space -Good A 0.33 55 14.8
Impervious Area A 0.90 98 71.7
Cumulative Curve # = 86.5

Triangle Site Design, PLLC
Curve Number Calculation (CN)
Post -Developed Bypass Conditions
Drainage Area acres): 0.77
Existing Soil Groups:
Soil Group Map Symbol Soil Description Acres Percent of DA
A NrB Norfolk, Georgeville, and Faceville 0.77 100%
Proposed Land Uses:
Land Use Description Existing Soil Group Acres Curve # Weighted CN
Wooded - Good A 0.00 54 0.0
Open Space - Good A 0.77 55 55.0
Impervious Area A 0.00 98 0.0
Cumulative Curve # = 55.0

Proposed Wet Pond
Project Information
Project Name: Dollar General - Middlesex
Project #:
Designed by: CID Date: 10/13/2021
Revised by: Date:
Checked by: Date:
Site Information
Sub Area Location: Drainage To Proposed Wet Pond
Drainage Area (DA) = 1.23 Acres 53,402 sf
Impervious Area (IA) = 0.90 Acres 38,890 sf
Percent Impervious (1) = % 72.82 %
Required Surface Area
Permament Pool Depth: 3.41 ft Non -Coastal County
SA/DA = 2.44
Min Peq'd Surface Area = 1,303 sf (at Permanent Pool
Required WQv Storage Volume
Design Storm = inch Non -Coastal County
Determine Rv Value = 0.05 + .009 (1) = 0.705 in/in
Storage Volume Required = 3.139 cf (above Permanent Pool)
Elevations
Top of Pond Elevation =
262.00
ft
Temporary Pool Elevation =
259.90
ft
Permanent Pool Elevation =
259.00
ft
Shelf Begining Elevation =
259.50
ft
Forebay Weir =
258.00
ft
Shelf Ending Elevation =
258.50
ft
Bottom Elevation =
253.00
ft
Permanent Pool Area
Area @ Top of Permanent Pool = 2,205 sf
Volume of Temporary Storage = 3,560 cf
Is Permenant Pool Surface Area Sufficient (yes/no)? ( 2205 > 1303 ) sf
Volume of Storage for Design Storm = as ( 3560 > 3139 ) cf

Incremental Drawdown Time
STORMWATER POND
INCREMENTAL DRAWDOWN METHOD -Water Quality Volume
Project Information
Project Nar Dollar General - Middlesex
Project #:
asigned by: CID Date: 10/13/2021
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 CD . D2 (Z-D/24-Ei)^('2)
Q2 = 0.372 Co' D"(Z-Ei)n('rz)
Q,=0
1 in
0.6
259
Orifice Inv.
0.00
to 259
259
to 259.1
259.1
to 260
Incremental Drawdown Method
Countour
Contour
Area
Incremental
Volume
Stage, Z
Zone
Q
Drawdown
Time
sq ft
cu ft
ft
cfs
min
259.00
3 250
0
0.00
2.00
0.000
259.50
4095
1.836
0.50
3.00
0.018
1.724
259.90
4525
1.724
0.40
3.00
0.024
1,183
Total
--
3.560
--
-
—
2,907
Drawdown Time = Incremental Volume / Q / 60sec/min
Summary
Total Volume = 3,660 cf
Total Time = 2,907 min
Total Time = 2.02 days Between 2 & 5
10/13/2021 Prop Wet Pond- new design -Middlesex 1 of 1

Project: Pond #1
Date: 10/13/2021
Main -Pond Contours -Volumes
Elevation
Main -Pond Incremental Vol.
Accumulated Vol.
Description
259
21205
968
5,821
A2 (Perm —Pool)
258.5
1,665
791
4,854
Al (Bottom —Shelf)
258
1,500
1,343
4,063
257
1,185
1,045
2,720
256
905
780
1,675
255
655
548
895
254
440
348
348
253
255
0
0
A3 (Bottom —Pond)
Forebay Contours -Volumes
Elevation
FBI
FB2 FB3 Total -Areas
Incremental Vol.
Accumulated Vol.
259
875
875
400
1,104
258.5
725
725
326
704
258
580
580
378
378
257
85
90 175
0
0
Forebay Volume
Average Depth (Option 1)
Average Depth Calculation (Option 2)
Vpp
permeter of shelf
width of shelf
Al (Bottom —Shelf):
Average Depth =
19.0% *Between 15% & 20%
2.92 *At least 3' average depth
5,821
188
3
1,665
3.41

Proposed Wet Pond #1
Dct Information
Project Name: Dollar General - Middlesex
Project #:
Designed by: CID Date: 10/13/2021
Revised by: Date:
Checked by: Date:
Information
Sub Area Location:
Drainage to Proposed Pond
Drainage Area (DA) =
1.23 Acres
Impervious Area (IA) =
0.90 Acres
Percent Impervious (1) =
72.82 % (Drainage Area)
ce Sizing
Orifice Size = 1.00 in (Diameter)
Drawdown Time = 2.02 days (Incremental Draw Down Method)
less than 5 days (yes/no) ? yes
greater than 2 day (yes/no) ? yes
-Flotation Device
4' x 4' Outlet Structure
Area:
16.0
sf
Volume:
_
2272.0
cf
Weight:
141773
Ibs
Factor of Safety
1.20
IT Req'd of Anti -Flotation Device:
170,127
Ibs
Volume of Concrete Req'd:
1134.2
cf
(Water Displaced - Top of Pond to Bottom of Pond)
(Unit WT of Concrete = 150 pcf)
Volume Provided: 85.5 cf (4'x4' riser x 3.0'=48.Ocf, 5'x5' footing x 1.5'=37.5cf)

Z
tz
i
J
� O
zz
0

-STAGE/STORAGE TABLE
STAGE
ELEVATION
CONTOUR
(FT)
(FT)
AREA (SF)
0.0
259.0
3250
0.5
259.5
4095
0.9
259.9
4525
1.0
260.0
4635
2.0
261.0
5760
3.0
262.0
6880
STORMWATER
RIVER BASIN:
RECEIVING STREAM:
STREAM INDEX:
CLASSIFICATION:
HUC:
LATITUDE/LONGITUDE:
MANAGEMENT
WET POND DESIGN SUMMARY
DESIGN
NEUSE
TURKEY SWAMP
27-86-14-3-(1)
C; NSW
03020203
N35.859314', W-78.177350'
INCREMENTAL TOTAL
STORAGE (CF) STORAGE (CF)
0
0
1836
1836
1724
3560 (WQv)
458
4018
5198
9216
6320
15536
DRAINAGE AREA TO WET POND: 1.23 ACRES
SITE IMPERVIOUS AREA TO WET POND: 0.90 ACRES
OFF -SITE DESIGN IMPERVIOUS AREA TO WET POND: 0.00 ACRES
TOTAL DESIGN IMPERVIOUS AREA TO WET POND: 0.90 ACRES
PRE -DEVELOPED TO POST -DEVELOPED POST -DEVELOPED POST -DEVELOPED POST -DEVELOPED
POND TO POND THRU RONRCOMBINED
DRAINAGE AREA: 2.00 AC 1.23 AC 0.77 AC
CURVE NUMBER: 55.5 86.5 55.0
TIME OF CONCENTRATION: 10 MIN 5 MIN 10 MIN
1.0" STORM EVENT: 0.182 CFS 0.011 CFS
1-YEAR STORM EVENT: 0.123 CFS 3.210 CFS 0.028 CFS 0.034 CFS 0.062 CFS
10-YEAR STORM EVENT: 2.831 CFS 7.306 CFS 1.181 CFS 1.022 CFS 2.203 CFS
100-YEAR STORM EVENT: 8.707 CFS 12.83 CFS 7.593 CFS 3.246 CFS 10.84 CFS

�W
-El;
!ME
W99
1*9L

a
N
-L
11

RISER STRUCTURE
4" PVC SCREW CAP —_
FOR CLEANING ACCESS
12" MIN. EXTEND 4"
IPVC THROUGH
RISER
STRUCTURE
4"x4" PVC
PERM. POND ELEV.=259.0
12" MIN.
1"DIA. HOLE DRILLED
INTO BOTTOM CAP
PVC DRAIN OUTLET
TAD AC CTDU6TURE NOT SHOWN FOR CLARITY
TRASH RACK)
OUTLET CONTROL STRUCTURE -- INCREMENTAL WEIR

Pond Report s
Hydraflow Hydrographs Extension for AutoCADO Civil 3D® 2009 by Autodesk, Inc. v6.066
Wednesday, Oct 13, 2021
Pond No. 1 - Wet Pond
Pond Data
Contours - User -defined contour areas. Average end area method used for volume calculation. Begining Elevation = 259.00 ft
Stage / Storage Table
Stage (ft) Elevation (ft)
Contour area (sqft)
Incr. Storage (cuft)
Total storage (cuft)
0.00 259.00
3,250
0
0
0.50 259.50
4,095
1,836
1,836
0.90 259.90
4,525
1,724
3,560
1.00 260.00
4,635
458
4,018
2.00 261.00
5,760
5,198
9,216
3.00 262.00
6,880
6,320
15,536
Culvert / Orifice Structures
Weir Structures
[A]
[B]
[C]
[PrfRsr]
[A]
[B]
[C]
[D]
Rise (in)
= 15.00
1.00
Inactive
Inactive
Crest Len (ft)
= 1.00
15.00
Inactive
Inactive
Span (in)
= 15.00
1.00
0.00
0.00
Crest El. (ft)
= 260.30
260.80
0.00
0.00
No. Barrels
= 1
1
0
0
Weir Coeff.
= 3.33
2.60
3.33
3.33
Invert El. (ft)
= 259.00
259.00
0.00
0.00
Weir Type
= Rect
Broad
---
---
Length (ft)
= 28.00
1.00
0.00
0.00
Multistage
= Yes
Yes
No
No
Slope (%)
= 1.79
0.50
0.00
n/a
N-Value
= .013
.013
.013
n/a
Orifice Coeff.
= 0.60
0.60
0.60
0.60
Exfil.(in/hr)
= 0.000 (by
Contour)
Multi -Stage
= n/a
Yes
No
No
TW Elev. (ft)
= 0.00
Stage (ft)
3.00
2.00
1.00
a'TaTa7
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
Elev (ft)
262.00
261.00
260.00
25900
0.00 1.00 200 3.00 4.00 5.00 6.00 7.00 8.00 9.00 10.00
Total Q Discharge (cfs)

Hydrograph Summary Rep 'Ffydraflow Hydrographs Extension for AutoCAD® Civil 3D0 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
1
SCS Runoff
0.123
2
726 1,267
------
-
Pre -Developed -Overall Site
2
SCS Runoff
3.210
2
716 6,506
-------
- —
------
Post Developed to Pond
3
Reservoir
0 028
2
1440 6,049
2
260.24
5,273
Post Through Pond
4
SCS Runoff
0.034
2
730 438
- - -
- —
Post Developed Bypass
6
SCS Runoff
0.182
2
150 880
-- -
-
SCM Post -Developed
7
Reservoir
0.011
2
366 810
6
259.21
776
1.0-in Storm Thru Pond
Wet Pond_Middlesex.gpw
Return Period: 1 Year
Wednesday, Oct 13, 2021

z
Hydrograph Report
Hydraflow Hydrographs Extension for AutoCADO Civil 3DO 2009 by Autodesk, Inc. v6.066
Hyd. No. 1
Pre -Developed -Overall Site
Hydrograph type
= SCS Runoff
Storm frequency
= 1 yrs
Time interval
= 2 min
Drainage area
= 2.000 ac
Basin Slope
= 0.0 %
Tc method
= USER
Total precip.
= 2.83 in
Storm duration
= 24 hrs
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. 1 Time (min)
Wednesday, Oct 13, 2021
Peak discharge = 0.123 cfs
Time to peak
= 726 min
Hyd. volume
= 1,267 cuft
Curve number
= 55.8
Hydraulic length
= 0 ft
Time of conc. (Tc)
= 10.00 min
Distribution
= Type II
Shape factor
= 484
Pre -Developed -Overall Site
Hyd. No. 1 -- 1 Year

Ri
Hydrograph Report
HydraFlow Hydrographs Extension for AutoCAD® Civil 3D® 2009 by Autodesk, Inc. v6.066
Hyd. No. 2
Post Developed to
Pond
Hydrograph type
= SCS Runoff
Storm frequency
= 1 yrs
Time interval
= 2 min
Drainage area
= 1.230 ac
Basin Slope
= 0.0 %
Tc method
= USER
Total precip.
= 2.83 in
Storm duration
= 24 hrs
Q (cfs)
4.00
3.00
2.00
1.00
0.00
0 120 240
— Hyd No. 2
Wednesday, Oct 13, 2021
Peak discharge = 3.210 cfs
Time to peak
= 716 min
Hyd. volume
= 6,506 cuft
Curve number
= 86.5
Hydraulic length
= 0 ft
Time of conc. (Tc)
= 5.00 min
Distribution
= Type II
Shape factor
= 484
Post Developed to Pond
Hyd. No. 2 -- 1 Year
360 480 600 720 840 960
Q (Cfs)
4.00
3.00
'r O M
1.00
0.00
1080 1200 1320 1440
Time (min)

Hydrograph Report
4
Hydraflow Hydrographs Extension for AutoCADO Civil 3D® 2009 byAutodesk, Inc. v6.066
Hyd. No. 3
Post Through Pond
Hydrograph type = Reservoir
Storm frequency = 1 yrs
Time interval = 2 min
Inflow hyd. No. = 2 - Post Developed to Pond
Reservoir name = Wet Pond
Storage Indication method used
M 11
2.00
1.00
Peak discharge
Time to peak
Hyd. volume
Max. Elevation
Max. Storage
Wednesday, Oct 13, 2021
= 0.028 cfs
= 1440 min
= 6,049 cuft
= 260.24 ft
= 5,273 tuft
Post Through Pond
Hyd. No. 3 -- 1 Year
600 1200 1800 2400 3000 3600 4200 4800 5400
Hyd No. 3 Hyd No. 2 ® Total storage used = 5,273 cuft
Q (cfs)
4.00
MR
2.00
1.00
0.00
6000
Time (min)

0
Hydrograph Report
Hydraflow Hydrographs Extension for AutoCADO Civil 3DO 2009 by Autodesk, Inc. v6.066
Hyd. No. 4
Post Developed Bypass
Hydrograph type
= SCS Runoff
Storm frequency
= 1 yrs
Time interval
= 2 min
Drainage area
= 0.770 ac
Basin Slope
= 0.0 %
Tc method
= USER
Total precip.
= 2.83 in
Storm duration
= 24 hrs
Q (cfs)
0.10 - — 0.10
0.09 0.09
0.08 - 0.08
0.07 - 0.07
0.06 0.06
0.05 0.05
0.04 0.04
0.03 0.03
0.02 -I - 0.02
0.01 — 0.01
0.00 0.00
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Time (min)
Hyd No. 4
Wednesday, Oct 13, 2021
Peak discharge = 0.034 cfs
Time to peak
= 730 min
Hyd. volume
= 438 cuft
Curve number
= 55
Hydraulic length
= 0 ft
Time of conc. (Tc)
= 10.00 min
Distribution
= Type II
Shape factor
= 484
Post Developed Bypass
Hyd. No. 4 -- 1 Year

Hydrograph Report
7
Hydraflow Hydrographs Extension forAutoCADS Civil 3D® 2009 byAutodesk, Inc. v6.066
Wednesday, Oct 13, 2021
Hyd. No. 6
SCM Post -Developed
Hydrograph type =
SCS Runoff
Peak discharge
= 0.182 cfs
Storm frequency =
1 yrs
Time to peak
= 150 min
Time interval =
2 min
Hyd. volume
= 880 cuft
Drainage area =
1.230 ac
Curve number
= 86.5
Basin Slope =
0.0 %
Hydraulic length
= 0 ft
Tc method =
USER
Time of conc. (Tc)
= 5.00 min
Total precip. =
1.00 in
Distribution
= SCS 6-Hr
Storm duration =
6.00 hrs
Shape factor
= 484
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
SCM Post -Developed
Hyd. No. 6 -- 1 Year
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
0
HydraFlow Hydrographs Extension for AutoCAD® Civil 3D®2009 byAutodesk, Inc. v6.066
Hyd. No. 7
1.0-in Storm Thru Pond
Hydrograph type = Reservoir
Storm frequency = 1 yrs
Time interval = 2 min
Inflow hyd. No. = 6 - SCM Post -Developed
Reservoir name = Wet Pond
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 = 776 cult Time (min)
Wednesday, Oct 13, 2021
Peak discharge = 0.011 cfs
Time to peak
= 366 min
Hyd. volume
= 810 cuft
Max. Elevation
= 259.21 ft
Max. Storage
= 776 cuft
1.0-in Storm Thru Pond
Hyd. No. 7 -- 1 Year

`11
Hydrograph Summary Rep❑
—Ffydraflow 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
(cult)
Inflow
hyd(s)
Maximum
elevation
(ft)
---
Total
strge used
(cuft)
Hydrograph
description
1
SCS Runoff
2.831
2
722
8,287
------
- —
Pre -Developed -Overall Site
2
SCS Runoff
7.306
2
716
15,311
-
- -
Post Developed to Pond
3
Reservoir
1.181
2
726
14,734
2
260.79
8,136
Post Through Pond
4
I
SCS Runoff
1.022
2
722
3,043
------
-----
Post Developed Bypass
I
6
SCS Runoff
0.000
2
n/a
0
- --
-----••
—
SCM Post -Developed
7
Reservoir
0.000
2
n/a
0
6
259.00
0.000
1.0-in Storm Thru Pond
Wet
Pond_Middlesex.gpw
Return Period:
i
Wednesday,
10
Year
Oct 13, 2021

11
Hydrograph Report
Hydraflow Hydrographs Extension for AutoCADO Civil 3DO2009 byAutodesk, Inc. v6.066
Hyd. No. 1
Pre -Developed -Overall Site
Hydrograph type
= SCS Runoff
Storm frequency
= 10 yrs
Time interval
- 2 min
Drainage area
= 2.000 ac
Basin Slope
= 0.0 %
Tc method
= USER
Total precip.
= 5.15 in
Storm duration
- 24 hrs
Q (cfs)
3.00
2.00
1.00
Wednesday, Oct 13, 2021
Peak discharge = 2.831 cfs
Time to peak
- 722 min
Hyd. volume
= 8,287 cuft
Curve number
- 55.8
Hydraulic length
= 0 ft
Time of conc. (Tc)
= 10.00 min
Distribution
= Type II
Shape factor
= 484
Pre -Developed -Overall Site
Hyd. No. 1 -- 10 Year
120 240 360 480 600 720 840
Hyd No. 1
Q (cfs)
3.00
2.00
1.00
0.00
960 1080 1200 1320 1440 1560
Time (min)

Hydrograph Report
iM
Hydraflow Hydrographs Extension for AutoCADO Civil 3DO2009 byAutodesk, Inc. v6.066
Hyd. No. 2
Post Developed to
Pond
Hydrograph type
= SCS Runoff
Storm frequency
= 10 yrs
Time interval
= 2 min
Drainage area
= 1.230 ac
Basin Slope
= 0.0 %
Tc method
- USER
Total precip.
= 5.15 in
Storm duration
- 24 hrs
M
4.00
2.00
M
Wednesday, Oct 13, 2021
Peak discharge = 7.306 cfs
Time to peak
= 716 min
Hyd. volume
= 15,311 cuft
Curve number
= 86.5
Hydraulic length
= 0 ft
Time of conc. (Tc)
= 5.00 min
Distribution
= Type II
Shape factor
= 484
Post Developed to Pond
Hyd. No. 2 -- 10 Year
120 240 360 480 600 720 840 960 1080 1200
Hyd No. 2
Q (cfs)
8.00
. ��
4.00
2.00
0.00
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 = 10 yrs
Time interval = 2 min
Inflow hyd. No. = 2 - Post Developed to Pond
Reservoir name = Wet Pond
Storage Indication method used.
M
4.00
2.00
Peak discharge
Time to peak
Hyd. volume
Max. Elevation
Max. Storage
13
Wednesday, Oct 13, 2021
= 1.181 cfs
= 726 min
= 14,734 tuft
= 260.79 ft
= 8,136 cuft
Post Through Pond
Hyd. No. 3 -- 10 Year
480 960 1440 1920 2400 2880 3360 3840 4320 4800
Hyd No. 3 Hyd No. 2 ® Total storage used = 8,136 cuft
Q (cfs)
8.00
W41
4.00
2.00
0.00
5280
Time (min)

14
Hydrograph Deport
Hydraflow Hydrographs Extension for AutoCADO Civil 3D® 2009 by Autodesk, Inc. v6.066
Hyd. No. 4
Post Developed Bypass
Hydrograph type
= SCS Runoff
Storm frequency
= 10 yrs
Time interval
= 2 min
Drainage area
= 0.770 ac
Basin Slope
= 0.0 %
Tc method
= USER
Total precip.
- 5.15 in
Storm duration
= 24 hrs
Q (cfs)
2.00
1.00
Wednesday, Oct 13, 2021
Peak discharge = 1.022 cfs
Time to peak
= 722 min
Hyd. volume
= 3,043 cuft
Curve number
= 55
Hydraulic length
= 0 ft
Time of conc. (Tc)
= 10.00 min
Distribution
= Type II
Shape factor
= 484
Post Developed 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)

17
Hydrograph Summary Re pC Oyraflow Hydrographs Extension for AUtoCAD® Civil 3DO 2009 by Autodesk, Inc. v6.066
Hyd. Hydrograph Peak Time Time to Hyd. Inflow Maximum Total Hydrograph
No. type flow interval peak volume hyd(s) elevation strge used description
(origin) (cfs) (min) (min) (cult) (ft) (cuft)
1
SCS Runoff
8.707
2
722
22,964
---
--
--
Pre -Developed -Overall Site
2
SCS Runoff
12.83
2
716
27,889
-
-
Post Developed to Pond
3
Reservoir
7.593
2
722
27,290
2
261.33
11,238
Post Through Pond
4
SCS Runoff
3.246
2
722
8,582
------
--- -
Post Developed Bypass
6
SCS Runoff
0.000
2
n/a
0
------
------
-
SCM Post -Developed
7
Reservoir
0.000
2
n/a
0
6
259.00
0.000
1.0-in Storm Thru Pond
Wet Pond_Middlesex.gpw I Return Period: 100 Year I Wednesday, Oct 13, 2021

18
Hydrograph Report
Hydraflow Hydrographs Extension forAutoCAD® Civil 3DO2009 byAutodesk, Inc. v6.066
Hyd. No. 1
Pre -Developed -Overall Site
Hydrograph type
= SCS Runoff
Storm frequency
= 100 yrs
Time interval
= 2 min
Drainage area
= 2.000 ac
Basin Slope
= 0.0 %
Tc method
= USER
Total precip.
= 8.28 in
Storm duration
= 24 hrs
Q (cfs)
10.00
M
. K It
4.00
2.00
M
Wednesday, Oct 13, 2021
Peak discharge = 8.707 cfs
Time to peak
722 min
Hyd. volume
= 22,964 cuft
Curve number
= 55.8
Hydraulic length
= 0 ft
Time of cone. (Tc)
= 10.00 min
Distribution
= Type II
Shape factor
= 484
Pre -Developed -Overall Site
Hyd. No. 1 -- 100 Year
Q (cfs)
10.00
M
4.00
2.00
0.00
120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Time (min)
Hyd No. 1

Hydrograph Report
■V
Hydraflow Hydrographs Extension for AutoCAD® Civil 31D® 2009 by Autodesk, Inc. v6.066
Hyd. No. 2
Post Developed to
Pond
Hydrograph type
= SCS Runoff
Storm frequency
= 100 yrs
Time interval
= 2 min
Drainage area
= 1.230 ac
Basin Slope
= 0.0 %
Tc method
= USER
Total precip.
= 8.28 in
Storm duration
= 24 hrs
Q (cfs)
14.00
12.00
10.00
e
Me]
4.00
2.00
w
Wednesday, Oct 13, 2021
Peak discharge = 12.83 cfs
Time to peak =
716 min
Hyd. volume =
27,889 cuft
Curve number =
86.5
Hydraulic length
= 0 ft
Time of conc. (Tc)
= 5.00 min
Distribution
= Type II
Shape factor
= 484
Post Developed to Pond
Hyd. No. 2 -- 100 Year
120 240 360 480 600
Hyd No. 2
Q (cfs)
14.00
12.00
10.00
e
we]
4.00
2.00
0.00
720 840 960 1080 1200
Time (min)

Hydrograph Report
20
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 - Post Developed to Pond
Reservoir name =
Wet Pond
Storage Indication method used.
Q (cfs)
14.00
12.00
10.00
ee
. We
4.00
2.00
0.00
0
Post Through Pond
Hyd. No. 3 -- 100 Year
Wednesday, Oct 13, 2021
Peak discharge = 7.593 cfs
Time to peak
= 722 min
Hyd. volume
= 27,290 cuft
Max. Elevation
= 261.33 ft
Max. Storage
= 11,238 cuft
Q (cfs)
14.00
12.00
10.00
ie,
AM,
4.00
2.00
0.00
120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Hyd No. 3 Hyd No. 2 Total storage used = 11,238 cult Time (min)

Hydrograph Report
Hydraflow Hydrographs Extension for AutoCADO Civil 3DO 2009 by Autodesk, Inc. v6.066
Hyd. No. 4
Post Developed Bypass
Hydrograph type
= SCS Runoff
Storm frequency
= 100 yrs
Time interval
= 2 min
Drainage area
= 0.770 ac
Basin Slope
= 0.0 %
Tc method
= USER
Total precip.
= 8.28 in
Storm duration
= 24 hrs
Q (cfs)
4.00
3.00
2.00
1.00
Post Developed Bypass
Hyd. No. 4 -- 100 Year
120 240 360 480 600 720 840
Hyd No. 4
21
Wednesday, Oct 13, 2021
Peak discharge = 3.246 cfs
Time to peak
= 722 min
Hyd. volume
= 8,582 cuft
Curve number
= 55
Hydraulic length
= 0 ft
Time of conc. (Tc)
= 10.00 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)

EROSION CONTROL CALCULATIONS

EROSION CONTROL. CALCS (RIP -RAP CALCULATIONS)
Project Information
Project Name:
Project #:
Designed by:
Revised by:
Checked by:
Dollar General
Pipe Diameter
Pipe Slope
Manning's number
Flow
Velocity
Date:
Date:
Date:
d= 15
s= 1.18
n= 0.013
Q= 4.92 cfs
V = 5.28 ft/s
Dissipator Dimensions *
Zone =
Stone Filling
Class = B
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
3.
1
2
3.8 ft
7.5 ft
8.8 ft
22 inches
6 inches
�14 7.5
8.8
* All units are in feet
** Dissipator pad designed for full f
RIP -RAP -Middlesex 10/13/2021 Page 1 of 3

RI_p-Rap_ Apron#2
Pipe Diameter
Pipe Slope
Manning's number
Flow
Velocity
d= 12
s= 0.95
n= 0.013
Q= 4 1.62 cfs
V = 3.75 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=
2
3.0 ft
6.0 ft
7.0 ft
22 inches
6 inches
6.0 1
1
* All units are in feet
** Dissipator pad designed for full f
RIP -RAP -Middlesex 10/13/2021 Page 2 of 3

Rip —Rap Apron#3
Pipe Diameter
Pipe Slope
Manning's number
Flow
Velocity
d= 15
s= 3.21
n= 0.01 3
4 Q= 4 1.58 cfs
It V = 1.29 ft/s
Dissipator Dimensions *
Zone = 4
Stone Filling
Class =
Entry Width ( 3
X Da ) _
Length ( 6
X Do ) _
Width (La
+ Dc,) _
Min. Thickness
=
Min. Stone Diameter=
0
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 -Middlesex 10/13/2021 Page 3 of 3

EROSION CONTROL CALCS (SKIMMER BASINS)
Project Information
Project Name:
Dollar General
Project #:
Designed by:
Date:
Revised by:
Date:
Checked by:
Date:
Skimmer Basin #1
Drainage Area
Total, AT= 1.B Ac
Disturbed, Ac= 18 Ac
10-year Runoff (Q10)
C = d 50
T. = 5.00 min
1100 7.10 in/hr
01e = 6.4 cfs
Surface Area Required
SA = 325sf x 010
SA= 2,077 sf
Volume Required
VR = 1800 cf/Ac x Ac
VR = 3,240 cf
Sediment Trap Dimensions
L = 66 ft (Spillway Length)
W = 32 ft (Spillway Width)
D = 2.0 ft (Depth of Storage)
Side Slopes = 2 :1
4W=
L,. = 74 ft
Lba= 58 ft W W1p,
WI-P= 40 ft Lpp=
Wb.1= 24 It
LAN Ratio= 2.1 :1 (must be 2:1 to 6:1)
Elevations Description
Elevation
Top of Berm
263.00 (allow 1 ft freeboard above spillway flow height)
Emergency Spillway
261,50
Sediment Storage
261.00
Cleanout Mark
260.00 (half of storage height)
Bottom
25900
Provided SAP=
2,112 sf > 2,077
Vp =
3,504.0 cf > 31240
Emergency Spillway - 10 Year Storm 110 =
7.10 in/hr
Q10 =
6.39 cfs
h =
0.5 ft
Cw =
3
LR,=
10 ft

Calculate Skimmer Size
Basin Volume in Cubic Feet 3,504 Cu.Ft Skimmer Size 1.s Inch
Days to Drain* 3 Days Orifice Radius 0,6. Inch[es]
Orifice Diameter 1.2 Inch[es]
'In NC assume 3 days to drain
Estimate Volume of Basin Let)gth Width
Top of water surface in feet 66 32 Feet VOLUME 3504 Cu. Ft.
Bottom dimensions in feet 58 24 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
4' x 4' Outlet Structure
Area:
Top of Basin Elev.:
Bottom of Basin Elev.:
Volume:
Weight:
Factor of Safety
WT Req'd of Anti -Flotation Device:
Volume of Concrete Req'd:
Volume Provided
Dollar General
16.0
sf
261.0
259.0
320
cf
1997
Ibs
1.20
2,396
Ibs
16.0
cf
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)

10/7/21, 3:15 PM
NORTH
AMERICAN
GREEN
CHANNEL ANALYSIS
> > > Igi17124L3fY Ditch#1
Name
Temporary Ditch#1
Discharge
2.7
Channel Slope
0.0219
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
None
C125
ECMDS 7.0
North American Green
5401 St. Wendel-Cynthiana Rd.
Poseyville, Indiana 47633
Tel. [phone]
> Fax [phone]
www.nagreen.com
ECMDS v7.0
Phase
Reach
Discharge
Velocity
Normal
Mannings N
Permissible
Calculated
Safety
I
Remarks Staple
Depth
Shear Stress
Shear Stress
Factor
Pattern
C125
Straight 2.7 cfs 3.09 ft/s 0.46 ft
0.031 2.3 Ibs/ft2
0.62 Ibs/ft2
3.69
STABLE D
Unvegetated
Underlying
Straight 2.7 cfs 3.09 ft/s 0.46 ft
0.031 0.53 Ibs/ft2
0.39 Ibs/ft2
1.36
STABLE D
Substrate
https://ecmds.com/project/139235/channel-analysis/211986/Show# 1/1

10/7/21, 3:16 PM ECMDS 7.0
NORTH North American Green
AMERICAN 5401 St. Wendel -Cynthiana Rd,
Poseyville, Indiana 47633
GREEN Tel. [phone]
> Fax [phone]
www.nagreen.com
ECM DS v7.0
CHANNEL ANALYSIS
> > > 1=P2.W Ditch#2
Name
Temporary Ditch#2
Discharge
2.5
Channel Slope
0.0205
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
None
C125
Phase
Reach
Discharge Velocity Normal
Depth
Mannings N
Permissible
Shear Stress
I Calculated
Shear Stress
Safety
I Factor
Remarks Staple
Pattern
C125
Straight 2.5 cfs 2.95 ft/s 0.45 ft
0.031 2.3 Ibs/ft2
0.57 Ibs/ft2
4.03
STABLE D
Unvegetated
Underlying
Straight 2.5 cfs 2.95 ft/s 0.45 ft
0.031 0.53 Ibs/ft2
0.36 Ibs/ft2
1.48
STABLE D
Substrate
hops://ecmds.com/project/139235/channel-analysis/211986/show 1/1