SW6200904_Report (Stormwater)_20210122

Storm water Management Report
January 14, 2021
Timberland Ranch
Calloway Road
Hoke County, NC
Prepared for:
Double D Engineering, PLLC
150 S. Page Street
Southern Pines, NC 28387
910-684-8646
Prepared by:
Triangle Site Design, PLLC
4004 Barrett Drive, Suite 101
Raleigh, NC 27609
[phone]
License#P-0619
TRIANGLE
�p S IT E D E S I G N
'��,�,; 1111I1111
•►y �rc::�e �f� 'i
SEAL �
Fri /tf anyaaalv"G9 � ���

OVERVIEW
FIGURES
SOILS SURVEY & SOIL INFORMATION
USGS IOPOGRAPHIC MAP
FEMA FIRM MAP
WAILR SURFACE CLASSIFICAIIONS
HUC
NOAA POINT PRLCIPIIAIION FREQUENCY ESIIMAILS
WATER QUANTITY -INFILTRATION TRENCH #1
DRAINAGE AREA MAP
CN VALUES
PRL-DLVLLOPMLNI HYDROGRAPHS
POST -DEVELOPMENT HYDROGRAPHS
TIME VS. VOLUME (STORAGE)
TIME VS. ELEVATION (STAGE)
ELLVATION-VOLUME-FLOW SUMMARY
SCM SUMMARY
IIML OF CONCLNIRAIION
WATER QUANTITY -INFILTRATION TRENCH #2
DRAINAGE AREA MAP
CN VALUES
PRE -DEVELOPMENT HYDROGRAPHS
POST -DEVELOPMENT HYDROGRAPHS
TIME VS. VOLUME (STORAGE)
TIME VS. ELEVATION (STAGE)
ELEVATION -VOLUME-FLOW SUMMARY
SCM SUMMARY
TIME OF CONCENTRATION
WATER QUANTITY -INFILTRATION TRENCH #3
DRAINAGE AREA MAP
CN VALUES
PRE -DEVELOPMENT HYDROGRAPHS
POST -DEVELOPMENT HYDROGRAPHS
TIME VS. VOLUME (STORAGE)
TIME VS. ELEVATION (STAGE)
ELEVATION -VOLUME-FLOW SUMMARY
SCM SUMMARY
TIME OF CONCENTRATION

WATER QUANTITY -INFILTRATION TRENCH #4
DRAINAGE AREA MAP
CN VALUES
PRL-DLVLLOPMLNI HYDROGRAPHS
POST -DEVELOPMENT HYDROGRAPHS
TIME VS. VOLUME (STORAGE)
TIME VS. ELEVATION (STAGE)
ELEVATION-VOLUML-FLOW SUMMARY
SCM SUMMARY
IIML OF CONCLNIRAIION
WATER QUANTITY -INFILTRATION TRENCH #5
DRAINAGE AREA MAP
CN VALUES
PRE -DEVELOPMENT HYDROGRAPHS
POST -DEVELOPMENT HYDROGRAPHS
TIME VS. VOLUME (STORAGE)
TIME VS. ELEVATION (STAGE)
ELEVATION -VOLUME-FLOW SUMMARY
SCM SUMMARY
TIME OF CONCENTRATION
WATER QUANTITY -INFILTRATION TRENCH #6
DRAINAGE AREA MAP
CN VALUES
PRE -DEVELOPMENT HYDROGRAPHS
POST -DEVELOPMENT HYDROGRAPHS
TIME VS. VOLUME (STORAGE)
TIME VS. ELEVATION (STAGE)
ELEVATION -VOLUME-FLOW SUMMARY
SCM SUMMARY
TIME OF CONCENTRATION
WATER QUANTITY -INFILTRATION TRENCH #7
DRAINAGE AREA MAP
CN VALUES
PRE -DEVELOPMENT HYDROGRAPHS
POST -DEVELOPMENT HYDROGRAPHS
TIME VS. VOLUME (STORAGE)
TIME VS. ELEVATION (STAGE)
ELEVATION -VOLUME-FLOW SUMMARY
SCM SUMMARY
TIME OF CONCENTRATION

WATER QUANTITY -INFILTRATION TRENCH #8
DRAINAGE AREA MAP
CN VALUES
PRL-DLVLLOPMLNI HYDROGRAPHS
POST -DEVELOPMENT HYDROGRAPHS
TIME VS. VOLUME (STORAGE)
TIME VS. ELEVATION (STAGE)
ELEVATION-VOLUML-FLOW SUMMARY
SCM SUMMARY
IIML OF CONCLNIRAIION

OVERVIEW
This report contains the storm water management overview for the proposed residential
development Timberland Ranch on Calloway Road in Hoke County. The project site is
currently un—developed. The proposed site consists of 524.7 acres and approximately
13.18 acres will be disturbed as part of this project for the construction of the site
improvements.
The proposed site is located in Flood Zone `X' as shown on FEMA FIRM Panel 3710940600J
with an effective date of 10/17/06 and Panel 3710940400J with an effective date of
10/17/06. Flood zones are subject to change by FEMA.
There are no existing stream or wetland features on the proposed property.
The proposed site satisfies a Low Density Project as a Phase II tipped county designation in
Hoke County. The development of the site will result in an impervious area of 1 ,010,543sf
(23.20ac — 4.43% impervious). The BUA is less than the 24% threshold and there are less
than two dwelling units/acre. Therefore, no Stormwater Control measures are required for the
project site. However, in order for the post —developed stormwater runoff to not exceed the
pre —developed stormwater runoff to the NCDOT roadway, infiltration trenches have been
designed for post— development peak attenuation only. There are eight infiltration trenches
throughout the site that are designed to provide peak flow attenuation for the 1, 2 & 10 year
storm events. In addition, in exchange for limiting the BUA, dispersed flow will be maximized
and stormwater conveyances will be vegetated.

Triangle Site Design, PLLC
Timberland Ranch, Hoke County, NC
Impervious Area - Infiltration Trench #1
Lots 6,000sf/lot x 14 lots
840001
1.93
Road
247671
0.57
Sidewalk
47021
0.11
Total
1134691
2.61
Impervious Area - Infiltration Trench #2
Lots 6 000sf lot x 6 lots
360001
0.83
Road
11589
0.27
Sidewalk
13441
0.03
Total
489331
1.12
Impervious Area - Infiltration Trench #3
Lots 12,000sf/lot x 6 lots
720001
1.65
Road
1 97501
0.22
Total
1 817501
1.88
Impervious Area - Infiltration Trench #4
Lots 12,000sf/lot x 8 lots
960001
2.20
Road
157961
0.36
Mail Kiosk
53451
0.12
Total
1171411
2.69
Impervious Area - Infiltration Trench #5
Lots 12,000sf/lot x 6 lots
720001
1.65
Road
1 96981
0.22
Total
1 816981
1.88
Im pervious Area - Infiltration Trench #6
Lots 12,000sf/lot x 2 lots
240001
0.55
Total
24000
0.55
Impervious Area - Infiltration Trench #7
Lots 15 000sf/lot x 8 lots
1200001
2.75
Road
140331
0.32
Total
1 1340331
3.08
Impervious Area - Infiltration Trench #8
Lots 15,000sf/lot x 10 lots 1500001
3.44
Road 170801
0.39
Total 1 167080
3.84

FIGURES

M „OE.3i G61
M,.ZZ.61 �61
OOL38E O009-1K 006SL8E OWSLBE OOLSLBE O39SLBE 009slec oxSNE OOESLBE
z z
Z Z
OOL—iBE 0009-12� 006918E OOBGZK OOLSLel OOD918E 0099LX OD6SL8E 00E9L8E
1
r
N CD0
N
N
cn
d
T
N
7
O
O
_ (D
O N
C d
O
U
U
z
c
C
jL
c
o
�0
Z
N
b
v
a,
v
ro
x
C
p
�
�
E
C
O
C
a
N
o
g
a
w
v
N
u7
3
�
n
N O
Gl �
7 N
ZQ
f+ _
ZU
Al „ZZ .6t o6C
9-1

Z
O
Q
0
Z
Ca
C
0
Z
W
0
W
J
a
m
0)
CL
O.
m
m
E
N
3
0
O
>.
N
N
n
E
O
lG
L
Cm, O
C UO
N N
U O O
7 E
O
C U m m
N d m =
U O C E O
N E m N
.L O C w L
�,•Q3 N
f0 m O_ O C
U m L N
N E fN
> w c >
� C w0 OL
16 O O to
a f
C N O. 7
m .0.L O U
E no o m
m w
m E m' N
' N N
E
N E c
O O U In
� m
C N CL N
1p _N N C m
W EuIn
w
N
C•)
2 N
m
S
N
N N
N
C
d
Z
CO
mcu
N 7 E
N �
y
n
O
N
C mE
L)
m
N
m
E
N
—
O
ya
(n
m
NLo
co
N
N y O
Z
04
V
U E In
O_
m
C d
O
0) a N 7 m
Q
O
N
$
O
O
d
L >
E
o w
o m o m
LU)
m
L
CL
3 N m m
U
N O
N C O_ - m
O m
ED
O C
Z 7
N
O
m
O O Q >.
m
m
l0
O
f0 w C
N
L... 3
m
C1
O
O_
m N
O
N O
O O 5 C
E a,
7
N
L
E L m In
E 0
O
N
Q. L
O) yp
0 U O N
O L
w
O C
U O
m
O.
y m ._
L N
O
N
_
m >N
U) 0)
— Z O O_ L
N iN 0 2
Y
0)
-
N
O N
3 J>
N
(n N O_ •C O
N Q C
f0
N
O
=
L
m
t3i1
L' C O
~O d
N
Q'
Z
L U
0
O
O
`�
N
tm
O
O
O •O,
.L..
C N
T
d O T
L d N
O, U m m 7
N
In
m "O"
N Q
U,
N
d 7
O Cl.
O C
m 7
w Fj U
U
O
•N
Q m
...
L C o m
E
E-6
u N
U N
0— m
E C 7
O O N N O
7
O O
Z Q
7 0
n 0
y
O
on m
L O
V, N
O C
CJ
N
>
N
7
(/) d
m O
E
N Z'
O D.
cc Ma,m
odo
O>> O
Comm
N— O
N�
L
_Z
0 7
_C)
O
wO7
m 0
a,Em
L O L
a E
U) > U
2 n-6 Q m
.�
H O
fn (A
Ui
O N
E
F- U .- N
W
m
A
c
�
T
L
a
o
C
U
L
�
c
m
v
N
v
o
V
10
O
t
v
N
E
d
:°
o
iy
°
a
m
a
w
8m
U U
0 Z
d
(n
O
7
2
Q
10
C
7
0
LL
w
m
0 t}
c i
`
`/
1
1.
m
3
m
0
a
m
�
m
v
m
m
E
C
0
C
m
0
N
q
0
N
Q O
0,
C
W
0
d
O
0
0
p
J 0
O
0
o
d
0 0
Q
m¢
c
a m
m
0
0
0
Z
mQ a
S
m m U
C) o
Z
mQ
E
a m m
C
f
nn❑❑❑ot
�
•oo®..
•
y
0,
`
O N
N
N
Q
Vl
O
U
7 >
m
O
U d
m O
U
(0
0
m
Z

S,e

I
Q
W
w
4)
>
9 W 9 N
O O
7
O
O
m
=
N y L E
a >
�
d
3
o
Q
c
Q
O y
x
-
Y O
=
i
Q
o° 0 Q
c= a d
m
O
M
E_
O
4
W C O N
a N O c V
O R
W
T
N
O d` C
D LL- Y
O
N
O '0
9
O
4
L
C C C O
.i �p N N
O
C
0 O
O
40
O 00
O C
0
V V
N
C
N
IL
C
M
r= C 0 0
•..
> O
W Q
Y_
m>
LL O
C C
C. N
U LL �" l,1 L
O
7
Q
M.
L_
L_ 7
aRL10/1
R
ma 3y
7 0 0 /0
O
�"�
O
C O
c
3"
r
3
N v n`
0
O m> `
J
`
w
W
N
Q
O >
U
¢
O 9 /0
Ii U Q Q
Q
Z
W
-
NU
Z
I -
_
W
- -- -
W
NQ a
¢ ¢
LL Q
�++ a
Q
WIx
U
Q
Q O
Q¢
0
x
W N
W O
o
m
vi xx
0
a
V
laz
U
C
C o
C
a
10
L
j. N
Q
o G �
N
E E u ��
R
C m
0• C
m
O.
d N 0 0
V H C'0 Lp
C F r
O p O E 9
a
�v0
C
70�
O y 0
odwyR
0 L
w.
Y O 7
N O
W W
C
E R o
a N
T W C o V
u
Y F C O
«a
m O C O
$uf 2i> 7 Ya o o
Q
0 0
��w
d N
aUQ
a O C E O
vv SCE
O T E 0 0
2 Eve
C U N O T CON C V
G R ON
:°
Q R
16 C
C O CL
O r O
R wo
a LL
.O O Q O
9 N m o
O r o 0
E p 0 j V
m C 7 C 16 L
V j F 0 Iq H 0 0'
O 10 O
N O.
C
IO Y
>
N 7 E 0
o j0 0 0
U! U- V p m
CL
O by d
>
N 9 3
v y f`') N O O
d
O 16 0 0
C
N r N O -' N =_ Q
O E N
m
G O YO
y '-
Q> N
N
N m R
V
O O
O C R O E T
U CO3 m J A U d 2
O C
O Z O
7 W L
W C O.
G> 0
- U p E O
n
I
n c m
Y O
E a N o >`
v o V 0 v
N
I II
I
I
I
r J
am)—0c
~ a R
3- c
w 3� E ov
> CL
R
f
3
,¢N
d N mom
a
O,O N9
x° `o c o
p NJ !
y R a w
mOa �� is
w
OV O.O..
OZ
O�OmWn
OOaCOa
E
W W
Z
O o E I
0-w
m a , Z 7
O
U
s$ o v
.�+ C O
F
Q
08
Q
a
+
R O p
E
O r X F O
Y 0
O. O
O C ,� O cL
n 0
E O
LLI
a
y a
N 7
O O
u r O O O O
"
C O
a E O� E 7
�
0
HVHR
R a
r-o3 —a
o r¢ or
�08�3
46
i
Or ` law
'M w
Z 4%..
W&
to
O
M
Z
F-
� ON
O
LO
N

V--,�p 61- 11Z1e
Surface Water OasWicetions:
S,,eam',ndex
18-31-11
Strewn Name
M:II Creek
De_cr pt.on
From source to
Rockfish Creek
iaa-ss•Fca' on
C
Date o`; CIBSs
August 31 1974
What aces tF, s C'a,s
mean'
More info
R."er Pas n
Cape Fee,
Timbedmd

2 cl
I
r
114V
-Irl,k 01

I /_ �, �-�

1/11/2021 Precipitation Frequency Data Server
NOAA Atlas 14,Volume 2, Version 3
Location name: Raeford, North Carolina, USA' r
Latitude: 35.0116°, Longitude:-79.3159°
Elevation: 390.38 ft-
'source: ESRI Maps '�501
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 j PF amiphical I Map.5 & aerials
PF tabular
PDS-based point precipitation frequency estimates with 90% confidence intervals (in inches)1
Duration
Average
recurrence interval (years)
�E
1100
200
500
1000
0.437
0.515
0.601
0.665
0.742
0.797
0.850
0.899
0.960
1.01
5-min
(0.398-0.482)
(0.4702.569
0.547-0.869
0:604-0.732}
(0.671-0.815)
J(0.720.0.874}
(0.763-0.931)
[fl.803 0.996
0.850.1,05 }
0.8$6-1.11
0.697
0.824
0.963
1.06
1.18
1.27
1.35
1.43
1.52
1.59
10-min
(0.636-0.769)
(0.752-0.910)
(0.877-1.06)
(0.967-1.17)
(1.07-1.30)
(1.15-1.39)
1 (1.21-1.4$)
(1.27-1.86)
1.34-1.87
(1.40-1.74
0.872
1 1.04
1.22
1.35
1.5071
1.61
1.71
1.80
1.91
1.99
15-min
[0.7956.962
0,9451.14
1,11-1.34(1,22-1,48)
)
[ 1.36-1.55]
1 (1.45-1.75)
1 (1.53-1.87)
1 (1.61-1.97
1.69-2.10
(1.75-2.19
30-min
1.092103x
(1.31--41358)
(1..587391)
(1,77 2515)11
(2.01 2?44)
{2.19 2?66}
1 (2.35-2.87]
1 (2: 0-3.07)
(2139-3.34)
(2: 4-3.5.4)
60-min
(1.3649s4
7 ,648099]
[2,p2 2Z45}
[2 152 70)
(2.8793.24
(2.95 3.80
3.23 3 95
3:51 4 30}
(3.86-4.79
4.14 5117]
1.74
2.1 -1-11
2.65
3.06
3.62
4.06
4.50
4.96
5.57
6.06
2-hr
1.58-1.94)
(1.91-2.35) 11
(2.402,95)
I [2.764AI)
1 (3.25-4.02
3.63-4.51
4.00.5.00
4.37-5.50
4.87-6.18
5.25ZY2)
1.84
2.23
2.82
3.28
3.92
4.45
4.99
5.56
6.36
7.00
3-hr
(1.67-2.06)
(2.02-2.50)
(2.55-3.14
96-3.8
3.514.36
3.96-4.94)
[4.41-5.53
(4.876.18)
5.51-7.05]
(6.00-7,76)
2.19
2.66
3.36
3.92
4.70
5.34
6.01
6.72
7.73
8.54
6-hr
(1.99.2.44)
(2.42-2,95)
L (3.05-3.72
(3.54-4.34)
4.76-5.89]
5.32-&132
5.89 7.39
68-8.40)
(7.30.6.38
2.59
3.14
3.98
4.67
5.64
6.45
7.30
8.22
9.53
10.6
12-hr
(2.34-2.88}
(2.84-3.49
(3.60-4.42
(4.20-5.18
[5.048.24
[5.71-7.11]
6,41-8.04)
14.9:04
BA5-10.5)
(8.9611.7)
24-hr
3.05
[2,83-3.30
3.69
3.42-4.00
4.67
(4.32 5.UB)
5.45
1 (5.02-5.89)
6.52
5.99-7,04}
7.37
(6,76-7.96)
8.25
11 (7.54-8,92)
9.17
8,36-9.90
10.4
9.46.11.3]
11.4
10.3-19:-0
2-day
(3.30-382(3.904.61)
1 (4: 9-5.79j
1 (5.78-6.71)
[fi, 64398]
(7.839.0.1j
11 (8. 9-310.1)
1 (9,48. 1-2)
(10.7-2.7)
(11.172-13;9)
3-day
3.76
4.53
4.23.4.86
5.66
(5.27-6.D6)
6.55
1 (6.09-7.01)
7.77
{T,208.32
8.75
8.09-9.3
9.76
8,GIR-10.5
10.8
8.91-11.8
12.2
(11.2-13.1
13.4
12.2-14.4
3.98
4.79
5.94
6.86
8.12
9.13
10.2
11.2
12.7
13.9
4-day
3.73-4.25)
1 (4.48-5,11) 11
(5,55.6,34)
1 (6,40-7.31)
(7.55-8.68
8.46-9.73)
13 3940.8
10.3-12.0)
(11.6-13.6)
1(12:6-14.8
4.61
6 1-71
6.76
7.75
9.11
10.2
11.3
12.5
14.0
15.3
7-day
--s
(4.31.4.93)
{5.16.6.89
(6.32-7.23)
(7,23 8.29
[8.48-9.74)
(9.46-10.9)
10.5-12.1
1 (11.5-13.3)
j (12.9-15.0]
(14.0-16A
10-day
5.29
(4.98.5.62]
6.30
5.93-5.70
7.61
-
7.188.68.11-9.17-10.6]
( 88.64 )
B_3910.0
11.1
10.4-11.8)
12.2
11.4-13.0}
13.3
fY2.4-14.2
14.8
[13.7-15.8
16.0
14.8-17.1
7.
9
20-day
7.53)
6.72
7.95 8191)
9.43-�10,6
[10�6-11.9)
(12112-13.7
13.13-15.1
14.5 6.5
1516
.9
1718 9.8
16?6- 1.4
8.83
10.4
12.2
13.5
15.3
16.7
18.0
19.4
21.2
22.6
30-day
8.35-9.34)
9.85.11.0)
11.5-12.9]
12.8-14.3
14.4-115.2) 11
(15.7-17.13)
1 (16.9-19.1) 11
(18.2-MS)
I (19.8-22,5)
(21,0-24.0)
45-day
(10.6- 1.8)
(124-13.8]
(4.13-159)
15(7616,6j
f17.18 9.5)
18?8-21.1
202 2.S
{21?5- 4.1]
2321426.1
(24.4-27.7
60-day
(12.173 4.1
14.8- 6.5]
(6.19- 8.7y
f1 5- 0.5
(204 2.7
21?824.4
23.4-28.0
2d?7627.7
8.2
25?5-29.8
27.8 1.
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 To12
PF graphical
https:Hhdsc.nws.noaa.gov/hdsctpfds/pfds_printpage.html?lat=35.0116&Ion=-79.3159&data=depth&units=english&series=pds 1 /4

WATER QUANTITY

NFILTRATION TRENCH #1

Triangle Site Design, PLLC
Timberland Ranch, Hoke County, NC
Curve Number Calculation (CN)
Pre -Developed Conditions #1
Drainage Anew (acres) 4.89
Existing Saii Grougs:
Soil GCOUp Map Symbol Soil Description
Acres
Percent of DA
A AuA Autryville Loamy Sand
0.49
10%
A CaB Candor Sand
4.40
90%
A/D Ra Rains Sandy Loam
0.00
0%
Existing Land Uses:
Land Use Description Existing Soil Group Acres
Curve #
Weighted CN
Open Space - Good Stand A 4.89
55
55.0
Cumulative Curve # =
55.0

Triangle Site Design, PLLC
Timberland Ranch, Hoke County, NC
Curve Number Calculation (CN)
Post -Developed Conditions to Infiltration Trench #1
Drainage Area (acres Z 4.89
Existing Soil Groups:
Soil Group Map Symbo! Soil Description
Acres
Percent of DA
A AuA Autryville Loamy Sand
0.49
10%
A CaB Candor Sand
4.40
90%
A/D Ra Rains Sandy Loam
0.00
0%
Proposed Land Uses:
Land Use Description Existing Soil Group Acres
Curve #
Weighted CN
Impervious Area -Residential Lots A 1.93
98
38.7
Impervious Area-Sidewalk/Road A 0.68
98
13.6
Open Space - Good Condition A 2.28
55
25.6
Cumulative Curve # =
78.0

Infiltration Trench Design
Site Information
Sub Area Location-
Drainage To Infiltration Trench 1
Drainage Area (DA) =
4.89 Acres 212925 sf
Impervious Area (IA) =
2.61 Acres 113469 sf
Percent Impervious (1) =
53:3 q
Required Water Quality Volume
Design Storm =
1 inch
Determine Rv Value =
0.05 + .009 (1) = 0.53 in/in
Water Quality Volume =
0.216 ac-ft
Water Quality Volume =
9,397 cf
Water Quality Volume =
0.530 inches of runoff
NOAA 1- ear, 24-hour event = 3.05 inches
Minimum Surface Area (SA)
SA = (12-FS-DV)/(K"T)
Factor of Safety (FS) =
2
Design Volume (DV) =
9397.4 cf
Hydraulic Conductivity of Soil =
39.00 in/hr
Max Dewatering Time =
72 hours
SA Required =
80.3 sf
SA Provided =
�J65 Sf

'STAGE/STORAGE TABLE
STAGE ELEVATION CONTOUR INCREMENTAL TOTAL
(FT) (FT) AREA (SF) STORAGE (CF) STORAGE (CF)
0.0
380.0
965
0
0
1.0
381.0
2005
1485
1485
2.0
382.0
3105
2555
4040
3.0
383.0
4275
3690
7730
4.0
384.0
5505
4890
12620 (WQv)
5.0
385.0
6805
6155
18775
STORMWATER MANAGEMENT DESIGN
INFILTRATION TRENCH #1
RIVER BASIN: CAPE FEAR
RECEIVING STREAM: MILL CREEK
STREAM INDEX: 18-31-11
STREAM CLASS: C
HUC: 03030004
SCM DESIGN SUMMARY
DRAINAGE AREA TO SCM: 4.89 ACRES
SITE IMPERVIOUS AREA TO SCM: 2.61 ACRES
QFF-SITE DESIGN IMPERVIOUS AREA TO SCM: 0.00 ACRES
TOTAL DESIGN IMPERVIOUS AREA TO SCM: 2.61 ACRES
PRE -DEVELOPED POST -DEVELOPED POST DEVELOPED
T4 SCM TO SC# THROUGH SCM
DRAINAGE AREA: 4.89 AC 4.89 AC
CURVE NUMBER: 55 78
TIME OF CONCENTRATION: 34 MIN 5 MIN
1-YEAR STORM EVENT:
0.275 CFS
9.685 CFS
0.000 CFS
2-YEAR STORM EVENT:
0.854 CFS
13.60 CFS
0.000 CFS
10-YEAR STORM EVENT:
3.840 CFS
25.37 CFS
0.000 CFS

qj
I

Pond Report s
Hydraflow Hydrographs Extension forAutoCAD® Civil 3D® 2009 byAutodesk, Inc. v6.066
Wednesday, Jan 13, 2021
Pond No. 1
- BMP Pond
Pond Data
Contours - User -defined contour areas.
Average end
area method used for volume calculation Begining Elevation
= 380.00 ft
Stage / Storage Table
Stage (ft)
Elevation (ft)
Contour area (sqft)
Incr. Storage (cuft) Total storage (cuft)
0.00
380.00
965
0 0
1.00
381.00
2.005
1,485 1,485
2.00
382.00
3.105
2,555 4,040
3.00
383.00
4.275
3,690 7,730
4.00
384.00
5,505
4.890 12,620
5.00
38500
6,805
6,155 18,775
Culvert / Orifice Structures
Weir Structures
[A] [B]
[C]
[PrfRsr]
[A] [B]
[C] [D]
Rise (in)
Inactive Inactive
Inactive
Inactive
Crest Len (ft) = 0.00 0.00
0.00 0.00
Span (in)
= 0.00 0.00
0.00
0.00
Crest El. (ft) = 0.00 0.00
0.00 0.00
No. Barrels
= 0 0
1
0
Weir Coeff. = 2.60 3.33
3.33 333
Invert El. (ft)
= 0.00 0.00
0.00
0.00
Weir Type = Broad ---
--- ---
Length (ft)
= 0.00 0.00
0.00
0.00
Multi -Stage = No No
No No
Slope (%)
= 0.00 0.00
000
n/a
N-Value
= .013 .013
.013
n/a
Orifice Coeff.
= 0.60 0.60
0.60
0.60
Exfil.(in/hr) = 39.000 (by Contour)
Multi -Stage
= n/a No
Yes
No
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 (ft)
5.00
4.00
3.00
2.00
1.00
0.00
0.00
Total Q
Stage / Discharge
1.00 2.00 3.00 4.00 5.00 6.00
Elev (ft)
385.00
38400
383.00
38200
381.00
380.00
700
Discharge (cfs)

H yd rog ra p h Summary ReRgra-flow Hydrographs Extension forAutoCAD® Civil 3D® 2009 by Autodesk, Inc. v6.066
Total I Hydrograph
rge used 1 description
(cuft)
BMP Pre -Developed
------ I BMP Post -Developed
i,132 I Post Through Pond
Vednesday, Jan 13, 2021

h:
Hydrograph Report
Hydraflow Hydrographs Extension forAutoCAD® Civil 31382009 byAutodesk, Inc. v6.066
Hyd. No. 1
BMP Pre -Developed
Hydrograph type = SCS Runoff
Storm frequency = 1 yrs
Time interval
= 2 min
Drainage area
= 4.890 ac
Basin Slope
= 0.0 %
Tc method
= USER
Total precip.
= 3.05 in
Storm duration
= 24 hrs
BMP Pre -Developed
Wednesday, Jan 13, 2021
Peak discharge = 0.275 cfs
Time to peak
= 752 min
Hyd. volume
= 3,645 cuft
Curve number
= 55
Hydraulic length
= 0 ft
Time of conc. (Tc)
= 34.00 min
Distribution
= Type II
Shape factor
= 484
Q (cfs) Q (cfs)
Hyd. No. 1 -- 1 Year
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
Time (min)
Hyd No. 1

Hydrograph Report
3
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 =
1 yrs
Time interval =
2 min
Drainage area =
4.890 ac
Basin Slope =
0.0 %
Tc method =
USER
Total precip. =
3.05 in
Storm duration =
24 hrs
M
4.00
2.00
BMP Post -Developed
Hyd. No. 2 -- 1 Year
120 240 360 480 600 720 840
Hyd No. 2
Wednesday, Jan 13, 2021
Peak discharge = 9.685 cfs
Time to peak =
718 min
Hyd. volume =
19,380 cuft
Curve number =
78
Hydraulic length
= 0 ft
Time of conc. (Tc)
= 5.00 min
Distribution
= Type II
Shape factor
= 484
Q (cfs)
10.00
M
ers,
4.00
2.00
0.00
960 1080 1200 1320 1440 1560
Time (min)

Hydrograph Report
4
Hydraflow Hydrographs Extension forAutoCAD® 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. Exfiltration extracted from Outflow
WN
. Me
4.00
2.00
Post Through Pond
Hyd. No. 3 -- 1 Year
120 240 360 480 600 720
Hyd No. 3 Hyd No. 2
Peak discharge
Time to peak
Hyd. volume
Max. Elevation
Max. Storage
Wednesday, Jan 13, 2021
= 0.000 cfs
= 796 min
= 0 cult
= 382.30 ft
= 5,132 cuft
Q (cfs)
10.00
M
.W
4.00
2.00
0.00
840 960 1080 1200 1320 1440
Total storage used = 5,132 cult Time (min)

H yd rog ra p h 5 u m m a ry Re Ri�ra' `w Hydrographs Extension for AutoCAD® Civil 3D® 2009 by Autodesk, Inc. v6.066
Total
Hydrograph
strge used
description
(cult)
------
BMP Pre -Developed
------
BMP Post -Developed
7,922
Post Through Pond
Wednesday, Jan 13, 2021

Hydrograph Report
7
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 =
4.890 ac
Basin Slope =
0.0 %
Tc method =
USER
Total precip. =
3.69 in
Storm duration =
24 hrs
BMP Pre -Developed
Wednesday, Jan 13, 2021
Peak discharge = 0.854 cfs
Time to peak
= 740 min
Hyd. volume
= 7,226 cuft
Curve number
= 55
Hydraulic length
= 0 ft
Time of conc. (Tc)
= 34.00 min
Distribution
= Type II
Shape factor
= 484
Q (cfs) Hyd. No. 1 -- 2 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
0.00 = - - 0.00
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Hyd No. 1 Time (min)

8
Hydrograph Report
Hydraflow Hydrographs Extension forAutoCAD® Civil 3D® 2009 byAutodesk, Inc. v6.066
Hyd. No. 2
BMP Post -Developed
Hydrograph type = SCS Runoff
Storm frequency = 2 yrs
Time interval
= 2 min
Drainage area
= 4.890 ac
Basin Slope
= 0.0 %
Tc method
= USER
Total precip.
= 3.69 in
Storm duration
= 24 hrs
Q (cfs)
14.00
12.00
10.00
E-1108M
. OR
4.00
2.00
BMP Post -Developed
Hyd. No. 2 -- 2 Year
Wednesday, Jan 13, 2021
Peak discharge = 13.60 cfs
Time to peak
= 718 min
Hyd. volume
= 27,345 cuft
Curve number
= 78
Hydraulic length
= 0 ft
Time of conc. (Tc)
= 5.00 min
Distribution
= Type II
Shape factor
= 484
Q (cfs)
14.00
12.00
10.00
Me
M
4.00
2.00
0.00 ' ` ' _ �' , _ 0.00
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Hyd No. 2 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. Exfiltration extracted from Outflow
Q (cfs)
14.00
12.00
10.00
W
4.00
2.00
0.00
0 120 240
— Hyd No. 3
Post Through Pond
Hyd. No. 3 -- 2 Year
360 480 600
Hyd No. 2
E
Wednesday, Jan 13, 2021
Peak discharge = 0.000 cfs
Time to peak
= 746 min
Hyd. volume
= 0 cult
Max. Elevation
= 383.04 ft
Max. Storage
= 7,922 cuft
Q (cfs)
14.00
12.00
10.00
e
M
4.00
2.00
0.00
720 840 960 1080 1200
Total storage used = 7,922 cult Time (min)

10
Hydrograph Summary Re Pyara «w Hydrographs Extension for AutoCAD® Civil 3138 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
3.840
2
738
21,276
------
2
SCS Runoff
25.37
2
716
51,549
------
-
------
BMP Post -Developed
3
Reservoir
0.000
2
688
0
Return Period:
2
10
384.72
16,961
Post Through Pond
Infiltration
Trench#1.gpw
Year
Wednesday,
Jan 13, 2021

11
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
= 4.890 ac
Basin Slope
= 0.0 %
Tc method
= USER
Total precip.
= 5.45 in
Storm duration
= 24 hrs
Q (cfs)
4.00
3.00
2.00
1.00
0.00
0 120 240
— Hyd No. 1
BMP Pre -Developed
Hyd. No. 1 -- 10 Year
360 480 600 720 840
Wednesday, Jan 13, 2021
Peak discharge = 3.840 cfs
Time to peak =
738 min
Hyd. volume =
21,276 cuft
Curve number =
55
Hydraulic length =
0 ft
Time of conc. (Tc) =
34.00 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)

12
Hydrograph Report
Hydraflow Hydrographs Extension forAutoCADO Civil 3DO2009 byAutodesk, Inc. v6.066
Hyd. No. 2
BMP Post -Developed
Hydrograph type =
SCS Runoff
Storm frequency =
10 yrs
Time interval =
2 min
Drainage area =
4.890 ac
Basin Slope =
0.0 %
Tc method =
USER
Total precip. =
5.45 in
Storm duration =
24 hrs
24.00
20.00
16.00
12.00
MM
4.00
BMP Post -Developed
Hyd. No. 2 -- 10 Year
Wednesday, Jan 13, 2021
Peak discharge = 25.37 cfs
Time to peak =
716 min
Hyd. volume
= 51,549 cuft
Curve number
= 78
Hydraulic length
= 0 ft
Time of conc. (Tc)
= 5.00 min
Distribution
= Type II
Shape factor
= 484
Q (cfs)
28.00
24.00
20.00
16.00
12.00
M. M
4.00
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440
Hyd No. 2 Time (min)

Hydrograph Report
13
Hydraflow Hydrographs Extension forAutoCAD® 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 - BMP Post -Developed
Reservoir name = BMP Pond
Storage Indication method used. Exfiltration extracted from Outflow.
24.00
20.00
16.00
12.00
e
4.00
Peak discharge
Time to peak
Hyd. volume
Max. Elevation
Max. Storage
Post Through Pond
Hyd. No. 3 -- 10 Year
Wednesday, Jan 13, 2021
= 0.000 cfs
= 688 min
= 0 cuft
= 384.72 ft
= 16,961 cuft
Q (cfs)
28.00
24.00
NOW
16.00
12.00
e
4.00
0.00
120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Hyd No. 3 Hyd No. 2 Total storage used = 16,961 cult Time (min)

£}
!
{�
§
�r
{»
i!
!
%
f«
!
{
f
k`
(;{�•
\§\\\|}
J!
;
77
§
`)
!
k/
#
it
b
f 7
■
� 2
IF
%t)
!
§
ƒ�+
,
|
�
E|
�
Bk
&
e!
|
-
r!§
|
§

INFILTRATION TRENCH #2

) rv� 1 A4-�,, 4-1 G-. —m-v\c L, -t� --P-

Triangle Site Design, PLLC
Timberland Ranch, Hoke County, NC
Curve Number Calculation (CN)
Pre -Developed Conditions #2
Drainage Area (acres 1.84
Existing so/l Groups:
soil GCOUD Map Symbol Soil Description Acres Percent of D_A
A AuA Autryville Loamy Sand 0.00 0%
A CaB Candor Sand 1.84 100%
A/D Ra Rains Sandy Loam 0.00 0%
Existing Land Uses;
Land Use Description Existing Soil Group Acres Curve # Weighted CN
Open Space - Good Stand A 1.84 55 55.0
Cumulative Curve # = 55.0

Triangle Site Design, PLLC
Timberland Ranch, Hoke County, NC
Curve Number Calculation (CN)
Post -Developed Conditions to Infiltration Trench #2
Drainage Area (acres): 1.84
Existing Soil Groups:
Soil Group Map Symbol Soil Description
Acres
Percent of DA
A AuA Autryville Loamy Sand
0.00
0%
A CaB Candor Sand
1.84
100%
A/D Ra Rains Sandy Loam
0.00
0%
Proposed Land Uses.
Land Use Description Existing Soil Group Acres
Curve #
Weighted CN
Impervious Area -Residential Lots A 0.83
98
44.2
Impervious Area-Sidewalk/Road A 0.29
98
15.4
Open Space - Good Condition A 0.72
55
21.5
Cumulative Curve # =
81.2

Infiltration Trench Desiqn
Site Information
Sub Area Location:
Drainage To Infiltration Trench 2
Drainage Area (DA) =
1.84 Acres 80165 sf
Impervious Area (IA) =
1.12 Acres 48933 sf
Percent Impervious (I) =
61.0 %
Required Water Quality Volume
Design Storm = 1 inch
Determine Rv Value = 0.05 + .009 (1) = 0.60 in/in
Water Quality Volume = 0.092 ac-ft
Water Quality Volume = 4,004 cf
Water Quality Volume = 0.599 inches of runoff
NOAA i ear, 24-hour event = 3.05 inches
Minimum Surface Area (SA)
SA = (12"FS`DV)/(K-T)
Factor of Safety (FS) =
2
Design Volume (DV) =
4004.0 cf
Hydraulic Conductivity of Soil =
2.17 in/hr
Max Dewatering Time =
72 hours
SA Required =
615.1 sf
SA Provided =
sf

o�
/
/
1
/
J,�
i

'STAGE
STORAGE
TABLE
STAGE
ELEVATION
CONTOUR
INCREMENTAL
TOTAL
(FT)
(FT)
AREA (SF)
STORAGE (CF)
STORAGE (CF)
0.0
381.0
840
0
0
1.0
382.0
2150
t495
1495
2.0
383.0
3565
2858
4353 (WQv)
3.0
384.0
5040
4303
8655
4.0
385.0
6590
5815
14470
STORMWATER MANAGEMENT DESIGN
INFILTRATION TRENCH #2
RIVER BASIN: CAPE FEAR
RECEIVING STREAM: MILL CREEK
STREAM INDEX: 18-31-11
STREAM CLASS: C
HUC: 03030004
SCM DESIGN SUMMARY
DRAINAGE AREA TO SCM: 1.84 ACRES
SITE IMPERVIOUS AREA TO SCM: 1.12 ACRES
QFF-SITE DESIGN IMPERVIOUS AREA TO SCM: 0.00 ACRES
TOTAL DESIGN IMPERVIOUS AREA TO SCM: 1.12 ACRES
PRE -DEVELOPED POST -DEVELOPED POST DEVELOPED
TO SCSI TO SCM THROUGH SCM
DRAINAGE AREA: 1.84 AC 1.84 AC
CURVE NUMBER: 55 81.2
TIME OF CONCENTRATION: 36 MIN 5 MIN
1-YEAR STORM EVENT:
0.103 CFS
4.249 CFS
0.000 CFS
2-YEAR STORM EVENT:
0.321 CFS
5.822 CFS
0.000 CFS
10-YEAR STORM EVENT:
1.445 CFS
10.40 CFS
0.000 CFS

xm ,z
Ma ,01 < INNS
I

Pond Report
Hydraflow Hydrographs Extension forAutoCAD® Civil 3DO 2009 by Autodesk, Inc. v6.066 Wednesday, Jan 13, 2021
Pond No. 1
- BMP Pond
Pond Data
Contours - User -defined contour areas.
Average end
area method used for volume calculation.
Begining Elevation
= 381.00 ft
Stage / Storage Table
Stage (ft)
Elevation (ft)
Contour area (sqft)
Incr. Storage (cuft)
Total storage (cuft)
0.00
381.00
840
0
0
1.00
38200
2.150
1,495
1,495
2.00
383.00
3.565
2,858
4,353
3.00
38400
5.040
4,303
8,655
4.00
38500
6.590
5,815
14,470
Culvert / Orifice Structures
Weir Structures
[A]
[B]
[C]
[PrfRSr]
[A] [Bl
[C]
[D]
Rise (in)
Inactive
Inactive
Inactive
Inactive
Crest Len (ft)
= 0.00 0.00
0.00
0.00
Span (in)
= 0.00
0.00
0.00
0.00
Crest El. (ft)
= 0.00 0.00
0.00
0.00
No. Barrels
= 0
0
1
0
Weir Coeff.
= 2.60 3.33
3.33
3.33
Invert El. (ft)
= 0.00
0.00
0.00
0.00
Weir Type
= Broad ---
---
---
Length (ft)
= 0.00
0.00
0.00
0.00
Multi -Stage
= No No
No
No
Slope (%)
= 0.00
0.00
0.00
n/a
N-Value
= .013
.013
.013
n/a
Orifice Coeff.
= 060
0.60
0.60
0.60
Exfil.(in/hr)
= 2.170 (by Contour)
Multi -Stage
= n/a
No
Yes
No
TW Elev. (ft)
= 000
Note:
Culvert/Onfice outflows
are analyzed under
inlet (ic) and outlet (oc) control Weir risers checked for orifice conditions
(ic) and submergence (s)
Stage (ft)
4.00
300
2.00
1.00
0.00
0.00 0.04
Total Q
Stage / Discharge
0.08 0.12 0.16 0.20 0.24 0.28 0.32 036
Elev (ft)
385.00
384.00
383.00
382.00
381.00
0.40
Discharge (cfs)

Hyd rog ra p h Summary Re Py?ra"flaw Hydrographs Extension for AutoCAD® Civil 3D® 2009 by Autodesk, Inc. v6.066

Hydrograph Report
Hydraflow Hydrographs Extension forAutoCAD® Civil 3D®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
= 1.840 ac
Basin Slope
= 0.0 %
Tc method
= USER
Total precip.
= 3.05 in
Storm duration
= 24 hrs
BMP Pre -Developed
2
Wednesday, Jan 13, 2021
Peak discharge = 0.103 cfs
Time to peak
= 752 min
Hyd. volume
= 1,372 cuft
Curve number
= 55
Hydraulic length
= 0 ft
Time of conc. (Tc)
= 36.00 min
Distribution
= Type II
Shape factor
= 484
Q (cfs) Hyd. No. 1 -- 1 Year 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)

3
Hydrograph Report
Hydraflow Hydrographs Extension forAutoCAD® Civil 3DO 2009 byAutodesk, Inc. v6.066
Hyd. No. 2
BMP Post -Developed
Hydrograph type = SCS Runoff
Storm frequency = 1 yrs
Time interval
= 2 min
Drainage area
= 1.840 ac
Basin Slope
= 0.0 %
Tic method
= USER
Total precip.
= 3.05 in
Storm duration
= 24 hrs
BMP Post -Developed
Wednesday, Jan 13, 2021
Peak discharge = 4.249 cfs
Time to peak =
718 min
Hyd. volume =
8,548 cuft
Curve number
= 81.2
Hydraulic length
= 0 ft
Time of conc. (Tc)
= 5.00 min
Distribution
= Type II
Shape factor
= 484
Q (cfs) Hyd. No. 2 -- 1 Year Q (cfs)
5.00 - 5.00
4.00 4.00
3.00 3.00
2.00 2.00
1.00 1.00
0.00 �- �.� - 0.00
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Hyd No. 2 Time (min)

4
Hydrograph Report
Hydraflow Hydrographs Extension forAutoCADO 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 - BMP Post -Developed
Reservoir name = BMP Pond
Storage Indication method used. Exfiltration extracted from Outflow
4.00
3.00
No
1.00
Peak discharge
Time to peak
Hyd. volume
Max. Elevation
Max. Storage
Wednesday, Jan 13, 2021
= 0.000 cfs
= 768 min
= 0 cult
= 383.04 ft
4,530 cult
Post Through Pond
Hyd. No. 3 -- 1 Year
240 480 720 960 1200 1440 1680 1920 2160
Hyd No. 3 Hyd No. 2 Total storage used = 4,530 cuft
Q (cfs)
5.00
4.00
3.00
2.00
1.00
0.00
2400
Time (min)

H yd rog ra p h Summary Re Ry3ra vw Hydrographs Extension for AutoCAD® Civil 3130 2009 by Autodesk, Inc. v6.066
Hydrograph
description
� Pre -Developed
Post -Developed
t Through Pond
in 13, 2021

Hydrograph Report
Hydraflow Hydrographs Extension forAutoCAD® Civil 3D®2009 by Autodesk, Inc. v6.066
Hyd. No. 1
BMP Pre -Developed
Hydrograph type = SCS Runoff
Storm frequency = 2 yrs
Time interval
= 2 min
Drainage area
= 1.840 ac
Basin Slope
= 0.0 %
Tic method
= USER
Total precip.
= 3.69 in
Storm duration
= 24 hrs
BMP Pre -Developed
7
Wednesday, Jan 13, 2021
Peak discharge = 0.321 cfs
Time to peak =
740 min
Hyd. volume =
2,719 cuft
Curve number =
55
Hydraulic length =
0 ft
Time of conc. (Tc) =
36.00 min
Distribution =
Type II
Shape factor
= 484
Q (cfs) Hyd. No. 1 -- 2 Year 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)

Hydrograph Report
Hydraflow Hydrographs Extension forAutoCAD® 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 =
1.840 ac
Basin Slope =
0.0 %
Tc method =
USER
Total precip. =
3.69 in
Storm duration =
24 hrs
5.00
4.00
MR
2.00
1.00
BMP Post -Developed
Hyd. No. 2 -- 2 Year
8
Wednesday, Jan 13, 2021
Peak discharge = 5.822 cfs
Time to peak
= 716 min
Hyd. volume
= 11,765 cuft
Curve number
= 81.2
Hydraulic length
= 0 ft
Time of conc. (Tc)
= 5.00 min
Distribution
= Type II
Shape factor
= 484
Q (cfs)
6.00
5.00
4.00
on
2.00
1.00
0.00
120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Hyd No. 2 Time (min)

Hydrograph Report
Hydraflow, Hydrographs Extension forAutoCAD® Civil 3DO 2009 by Autodesk, 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. Exfiltration extracted from Outflow
Post Through Pond
Wednesday, Jan 13, 2021
Peak discharge = 0.000 cfs
Time to peak
= 722 min
Hyd. volume
= 0 cuft
Max. Elevation
= 383.52 ft
Max. Storage
= 6,592 cuft
Q (cfs) Hyd. No. 3 -- 2 Year Q (cfs)
6.00 6.00
5.00 5.00
4.00 4.00
3.00 - 3.00
2.00 2.00
1.00 1.00
0.00 0.00
0 240 480 720 960 1200 1440 1680 1920 2160 2400 2640
Time (min)
Hyd No. 3 Hyd No. 2 Total storage used = 6,592 cult

10
H yd rog ra p h Summary Re Py3rlfl3w Hydrographs Extension for AutoCAD® Civil 3D® 2009 by Autodesk, Inc. v6.066
Hyd. Hydrograpt
No. type
(origin)
SCS Runoff
SCS Runoff
Reservoir
Infiltration Tren

Hydrograph Report
11
Hydraflow Hydrographs Extension forAutoCAD® Civil 3DO2009 byAutodesk, Inc. v6.066
Hyd. No. 1
BMP Pre -Developed
Hydrograph type =
SCS Runoff
Storm frequency =
10 yrs
Time interval =
2 min
Drainage area =
1.840 ac
Basin Slope =
0.0 %
Tc method =
USER
Total precip. =
5.45 in
Storm duration =
24 hrs
Q (cfs)
2.00
1.00
BMP Pre -Developed
Hyd. No. 1 -- 10 Year
120 240 360 480 600 720 840
Hyd No. 1
Wednesday, Jan 13, 2021
Peak discharge = 1.445 cfs
Time to peak
= 738 min
Hyd. volume
= 8,006 cuft
Curve number
= 55
Hydraulic length
= 0 ft
Time of conc. (Tc)
= 36.00 min
Distribution
= Type II
Shape factor
= 484
Q (cfs)
2.00
1.00
I I I I L- !_ 0.00
960 1080 1200 1320 1440 1560
Time (min)

Hydrograph Report
Hydraflow Hydrographs Extension for AutoCAD®Civil 3DO2009 byAutodesk, Inc. v6.066
Hyd. No. 2
BMP Post -Developed
Hydrograph type = SCS Runoff
Storm frequency = 10 yrs
Time interval
= 2 min
Drainage area
= 1.840 ac
Basin Slope
= 0.0 %
Tc method
= USER
Total precip.
= 5.45 in
Storm duration
= 24 hrs
10.00
M$
. OR
4.00
2.00
0.00
0 120 240
— Hyd No. 2
BMP Post -Developed
Hyd. No. 2 -- 10 Year
12
Wednesday, Jan 13, 2021
Peak discharge = 10.40 cfs
Time to peak
= 716 min
Hyd. volume
= 21,326 cuft
Curve number
= 81.2
Hydraulic length
= 0 ft
Time of conc. (Tc)
5.00 min
Distribution
= Type II
Shape factor
= 484
360 480 600 720 840
Q (cfs)
12.00
10.00
4.00
2.00
0.00
960 1080 1200 1320
Time (min)

i9l
Hydrograph Report
Hydraflow Hydrographs Extension forAutoCAD® Civil 31D0 2009 byAutodesk, Inc. v6.066
Hyd. No. 3
Post Through Pond
Hydrograph type = Reservoir
Storm frequency = 10 yrs
Time interval = 2 min
Inflow hyd. No. = 2 - BMP Post -Developed
Reservoir name = BMP Pond
Storage Indication method used Exfiltration extracted from Outflow
Post Through Pond
Wednesday, Jan 13, 2021
Peak discharge = 0.000 cfs
Time to peak
= 714 min
Hyd. volume
= 0 cuft
Max. Elevation
= 384.73 ft
Max. Storage
= 12,909 cuft
Q (cfs) Q (cfs)
Hyd. No. 3 -- 10 Year
12.00 - - 12.00
10.00 10.00
8.00 8.00
6.00 6.00
4.00 4.00
2.00 - 2.00
0.00 - = 0.00
0 240 480 720 960 1200 1440 1680 1920 2160 2400 2640
Time (min)
- Hyd No. 3 Hyd No. 2 Total storage used = 12,909 cuft

|
`
r
!
\/
|
}�
!
2
{�
�-
{`
!
|k
|
■ !|
§ §\{!|
I|
�
2$
�
�!
k
7 �
�
� -
■
a;
2
!
i||
§
_!.
§--
■
_
�
§
■
_\�r
\)!
!
§J!
'0
_
�
/
§

�-1 -a 4A-,

INFILTRATION TRENCH #3

1 n�;1�-le.. �e�cl„ �3

Triangle Site Design, PLLC
Timberland Ranch, Hoke County, NC
Curve Number Calculation (CN)
Pre -Developed Conditions #3
Drainage Area (acresZ 2.56
Existw 50il Groups:
Soil Group Map Symbol Soil Description
Acres
Percent of DA
A AuA Autryville Loamy Sand
0.00
0%
A CaB Candor Sand
2.56
100%
A/D Ra Rains Sandy Loam
0.00
0%
Existing Lnd_Uses
Land Use Description Existing Soil Group Acres
Curve #
Weighted CN
Open Space - Good Stand A 2.56
55
55.0
Cumulative Curve # =
55.0

Triangle Site Design, PLLC
Timberland Ranch, Hoke County, NC
Curve Number Calculation (CN)
Post -Developed Conditions to Infiltration Trench #3
OrainaQe Area jacresJ: 2.56
Existing Soil Groups:
Soil GLou
—P Map Symbol Soil Description
Acres
Percent of DA
A AuA Autryville Loamy Sand
0.00
0%
A CaB Candor Sand
2.56
100%
A/D Ra Rains Sandy Loam
0.00
0%
Proposed Land Uses:
Land Use Description Existing Soil Group Acres
Curve #
Weighted CN
Impervious Area -Residential Lots A 1.65
98
63.2
Impervious Area-Sidewalk/Road A 0.23
98
8.8
Open Space - Good Condition A 0.68
55
14.6
Cumulative Curve # =
86.6

Infiltration Trench Design
Site Information
Sub Area Location:
Drainage To Infiltration Trench 3
Drainage Area (DA) =
2.56 Acres 111705 sf
Impervious Area (IA) =
1.88 Acres 81750 sf
Percent Impervious (q =
73.2 %
Required Water Quality Volume
Design Storm = 1 inch
Determine Rv Value = 0.05 + .009 (1) = 0.71 in/in
Water Quality Volume = 0.151 ac-ft
Water Quality Volume = 6,597 cf
Water Quality Volume = 0.709 inches of runoff
NOAA 1- ear. 24-hour event = 3.05 inches
Minimum Surface Area (SA)
SA =
(12`FS•DV)/(K`T)
Factor of Safety (FS) =
2
Design Volume (DV) =
6596.7 cf
Hydraulic Conductivity of Soil =
2.17 in/hr
Max Dewatering Time =
72 hours
SA Required =
1013.3 sf
SA Provided =
1870 sf

'STAGE/STORAGE
TABLE
STAGE
ELEVATION
CONTOUR
INCREMENTAL
TOTAL
(FT)
(FT)
AREA (SF)
STORAGE (CF)
STORAGE (CF)
0.0
384.0
1870
0
0
1.0
385.0
3910
2890
2890
2.0
386.0
6100
5005
7895 (WQv)
3.0
387.0
8460
7280
15175
4.0
388.0
10980
9720
24895
STORMWATER MANAGEMENT
INFILTRATION TRENCH #3
RIVER BASIN: CAPE FEAR
RECEIVING STREAM: DILL CREEK
STREAM INDEX: 18-31-11
STREAM CLASS: C
HUC: 03030004
SCM DESIGN SUMMARY
DESIGN
DRAINAGE AREA TO SCM: 2.56 ACRES
SITE IMPERVIOUS AREA TO SCM: 1.88 ACRES
OFF -SITE DESIGN IMPERVIOUS AREA TO SCM: 0.00 ACRES
TOTAL DESIGN IMPERVIOUS AREA TO SCM: 1.88 ACRES
PRE -DEVELOPED POST -DEVELOPED POST DEVELOPED
TO SCM TO SCM THROUGH SCM
DRAINAGE AREA: 2.56 AC 2.56 AC
CURVE NUMBER: 55 86.6
TIME OF CONCENTRATION: 19 MIN 5 MIN
1-YEAR STORM EVENT:
0.189 CFS
7.505 CFS
0.000 CFS
2-YEAR STORM EVENT:
0.680 CFS
9.846 CFS
0.000 CFS
10-YEAR STORM EVENT:
3.093 CFS
16.35 CFS
0.000 CFS

i
0
�
NUM E "'�. 1111RS]uF➢m
G
M-wu SAIL
'^
L
~
U
U N
W 2
V
H
�
Z
I
p
J
L�
Z
dM ,pl < I"
oe

Pond Report s
Hydraflow Hydrographs Extension for AutoCAD@ Civil 3D® 2009 by Autodesk, Inc. v6.066
Thursday, Jan 14, 2021
Pond No. 1
- BMP Pond
Pond Data
Contours - User -defined contour areas.
Average end area method used for volume calculation. Begining Elevation
= 384.00
ft
Stage / Storage Table
Stage (ft)
Elevation (ft)
Contour area (sqft)
Incr. Storage (cuft) Total storage (cuft)
0.00
38400
1,870
0 0
1.00
38500
3,910
2,890 2,890
200
38600
6,100
5,005 7,895
3.00
38700
8,460
7,280 15,175
4.00
38800
10,980
9,720 24,895
Culvert / Orifice Structures
Weir Structures
[A]
[B]
[C]
[PrfRsr]
[A] [B]
[C]
[D]
Rise (in)
Inactive
Inactive
Inactive
Inactive
Crest Len (ft) = 0.00 0.00
0.00
0.00
Span (in)
= 0.00
0.00
0.00
0.00
Crest El. (ft) = 0.00 0.00
0.00
0.00
No. Barrels
= 0
0
1
0
Weir Coeff. = 2.60 3.33
3.33
3.33
Invert El. (ft)
= 0.00
0.00
0.00
0.00
Weir Type = Broad ---
---
---
Length (ft)
= 0.00
0.00
0.00
0.00
Multi -Stage = No No
No
No
Slope (%)
= 0.00
0.00
0.00
n/a
N-Value
= .013
.013
.013
n/a
Orifice Coeff.
= 0.60
0.60
0.60
0.60
Exfil.(in/hr) = 2.170 (by Contour)
Multi -Stage
= n/a
No
Yes
No
TW Elev. (ft) = 0.00
Stage (ft)
4.00
3.00
2.00
1.00
0.00
0.00 0.06
Total Q
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
0.12 0.18 0.24 0.30 0.36 0.42 0.48 0.54
Elev (ft)
388.00
387.00
386.00
385.00
384.00
0.60
Discharge (cfs)

H yd rog ra p h Summary Re Wy?raflow Hydrographs Extension for AutoCAD® Civil 3D® 2009 by Autodesk, Inc. v6.066

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 = 1 yrs
Time interval
= 2 min
Drainage area
= 2.560 ac
Basin Slope
= 0.0 %
Tc method
= USER
Total precip.
= 3.05 in
Storm duration
= 24 hrs
BMP Pre -Developed
Thursday, Jan 14, 2021
Peak discharge = 0.189 cfs
Time to peak
= 732 min
Hyd. volume
= 1,930 cuft
Curve number
= 55
Hydraulic length
= 0 ft
Time of conc. (Tc)
= 19.00 min
Distribution
= Type II
Shape factor
= 484
Q (cfs) Q (cfs)
Hyd. No. 1 -- 1 Year
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
Time (min)
Hyd No. 1

Hydrograph Report
Hydraflow Hydrographs Extension for AutoCADO Civil 3D@ 2009 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
= 2.560 ac
Basin Slope
= 0.0 %
Tc method
= USER
Total precip.
= 3.05 in
Storm duration
= 24 hrs
M
4.00
2.00
3
Thursday, Jan 14, 2021
Peak discharge = 7.505 cfs
Time to peak
= 716 min
Hyd. volume
= 15,260 cuft
Curve number
= 86.6
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)
8.00
It
4.00
2.00
0.00
1080 1200 1320 1440
Time (min)

4
Hydrograph Report
Hydraflow Hydrographs Extension forAutoCAD® 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 - BMP Post -Developed
Reservoir name = BMP Pond
Storage Indication method used. Exfiltration extracted from Outflow.
Q (cfs)
8.00
. W
4.00
2.00
240 480
Hyd No. 3
Post Through Pond
Hyd. No. 3 -- 1 Year
Peak discharge
Time to peak
Hyd. volume
Max. Elevation
Max. Storage
Thursday, Jan 14, 2021
= 0.000 cfs
= 1572 min
= 0 cult
= 386.08 ft
= 8,507 cuft
Q (cfs)
8.00
4.00
2.00
W, j I L0.00
720 960 1200 1440 1680 1920 2160 2400 2640 2880
Time (min)
Hyd No. 2 Total storage used = 8,507 cult

Hydrograph Summary Re Pyaraflow Hydrographs Extension forAutoCAD® Civil 3D® 2009 by Autodesk, Inc. v6.066
Hyd.
No.
Hydrograph
type
(origin)
Peak
flow
(cfs)
0.680
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
728
3,826
--
BMP Pre -Developed
2
SCS Runoff
9.846
2
716
20,204
-- -
------
BMP Post -Developed
3
Reservoir
0.000
2
690
0
2
386.52
11,699
Post Through Pond
i
Jan 14, 2021
Infiltration
Trench#3.gpw
Return Period:
2 Year
Thursday,

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 =
2.560 ac
Basin Slope =
0.0 %
Tc method =
USER
Total precip. =
3.69 in
Storm duration = 24 hrs
BMP Pre -Developed
7
Thursday, Jan 14, 2021
Peak discharge = 0.680 cfs
Time to peak
= 728 min
Hyd. volume
= 3,826 cuft
Curve number
= 55
Hydraulic length
= 0 ft
Time of conc. (Tc)
= 19.00 min
Distribution
= Type II
Shape factor
= 484
Q (cfs) Hyd. No. 1 -- 2 Year Q (cfs)
1.00 1.00
0.90 0.90
0.80 0.80
0.70 0.70
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. 1 Time (min)

Hydrograph Report
Hydraflow Hydrographs Extension forAutoCAD® Civil 3D® 2009 byAutodesk, Inc. v6.066
Hyd. No. 2
BMP Post -Developed
Hydrograph type =
SCS Runoff
Storm frequency =
2 yrs
Time interval =
2 min
Drainage area =
2.560 ac
Basin Slope =
0.0 %
Tc method =
USER
Total precip. =
3.69 in
Storm duration =
24 hrs
MIX
. M
4.00
2.00
0.00
0 120 240
Hyd No. 2
BMP Post -Developed
Hyd. No. 2 -- 2 Year
8
Thursday, Jan 14, 2021
Peak discharge = 9.846 cfs
Time to peak =
716 min
Hyd. volume =
20,204 cuft
Curve number
= 86.6
Hydraulic length
= 0 ft
Time of conc. (Tc)
= 5.00 min
Distribution
= Type II
Shape factor
= 484
360 480 600 720 840 960
Q (cfs)
10.00
MIL
. DO
4.00
2.00
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 = 2 yrs
Time interval = 2 min
Inflow hyd. No. = 2 - BMP Post -Developed
Reservoir name = BMP Pond
Storage Indication method used. Exfiltration extracted from Outflow.
M
M
4.00
2.00
240 480
Hyd No. 3
Post Through Pond
Hyd. No. 3 -- 2 Year
Peak discharge
Time to peak
Hyd. volume
Max. Elevation
Max. Storage
Thursday, Jan 14, 2021
= 0.000 cfs
= 690 min
= 0 cuft
= 386.52 ft
= 11,699 cuft
Q (cfs)
10.00
M
M
4.00
2.00
0.00
720 960 1200 1440 1680 1920 2160 2400 2640 2880
Hyd No. 2 Total storage used = 11,699 cult Time (min)

10
Hydrograph Summary Re PQra-flow Hydrographs Extension for AutoCAD® Civil 31302009 by Autodesk, Inc. v6.066
Hyd.
No.
Hydrograph
type
(origin)
Peak
flow
(cfs)
Time
interval
(min)
Time to
peak
(min)
Hyd.
volume
(cuft)
11,266
Inflow
hyd(s)
-
Maximum
elevation
(ft)
-
Total
strge used
(cuft)
Hydrograph
description
1
SCS Runoff
3.093
2
726
------
BMP Pre -Developed
2
SCS Runoff
16.35
2
716
34,423
------
--
--
BMP Post -Developed
3
Reservoir
0.000
2
932
0
2
387.61
21,056
Thursday,
Post Through Pond
Jan 14, 2021
Infiltration
Trench#3.gpw
Return Period:
10
Year

11
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 =
2.560 ac
Basin Slope =
0.0 %
Tc method =
USER
Total precip. =
5.45 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
Thursday, Jan 14, 2021
Peak discharge = 3.093 cfs
Time to peak =
726 min
Hyd. volume
= 11,266 cuft
Curve number
= 55
Hydraulic length
= 0 ft
Time of conc. (Tc)
= 19.00 min
Distribution
= Type II
Shape factor
= 484
Q (cfs)
4.00
3.00
2.00
1.00
960 1080 1200 1320 1440 1560
Time (min)

Hydrograph Report 12
Hydraflow Hydrographs Extension forAutoCADO Civil 31DO 2009 by Autodesk, Inc. v6.066 Thursday, Jan 14, 2021
Hyd. No. 2
BMP Post -Developed
Hydrograph type
= SCS Runoff
Peak discharge =
16.35 cfs
Storm frequency
= 10 yrs
Time to peak =
716 min
Time interval
= 2 min
Hyd. volume =
34,423 cuft
Drainage area
= 2.560 ac
Curve number =
86.6
Basin Slope
= 0.0 %
Hydraulic length =
0 ft
Tic method
= USER
Time of conc. (Tc) =
5.00 min
Total precip.
= 5.45 in
Distribution
= Type II
Storm duration
= 24 hrs
Shape factor
= 484
Q (cfs)
18.00
15.00
12.00
•1M
3.00
0.00
0 120 240 360 480 600 720
— Hyd No. 2
BMP Post -Developed
Hyd. No. 2 -- 10 Year
Q (cfs)
18.00
15.00
12.00
• 88
. 19
3.00
0.00
840 960 1080 1200
Time (min)

Hydrograph Report
Hydraflow, Hydrographs Extension forAutoCAD® Civil 31D0 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 - BMP Post -Developed
Reservoir name = BMP Pond
Storage Indication method used. Exfiltration extracted from Outflow.
15.00
12.00
9.00
6.00
3.00
0.00
0 240 480 720
Hyd No. 3 —
Post Through Pond
Hyd. No. 3 -- 10 Year
Peak discharge
Time to peak
Hyd. volume
Max. Elevation
Max. Storage
13
Thursday, Jan 14, 2021
= 0.000 cfs
= 932 min
= 0 cuft
= 387.61 ft
= 21,056 cuft
Q (cfs)
18.00
15.00
12.00
MH
3.00
0.00
960 1200 1440 1680 1920 2160 2400 2640 2880
Hyd No. 2 Total storage used = 21,056 cult Time (min)

£)
5
)\
§
{®
Ik
!
2
k-
i
|
!`
I}
�
°F
�
_■
$
;
K �
-
� -
■
2§ §|
K
§\ _/!�
■
■
�
211
■
I|/
{�k
�
■
$
k
Kk$
Olkt
|
§

NFILTRATION TRENCH #4

\Ac�-,Ai c,�,, 1 oc v c" t, `1

Triangle Site Design, PLLC
Timberland Ranch, Hoke County, NC
Curve Number Calculation (CN)
Pre -Developed Conditions #4
Drainage Area Lacrgjs 4.25
Existing Soil Groups:
Soil Grow Map Symbol Soil Description
Acres
Percent of DA_
A AuA Autryville Loamy Sand
0.00
0%
A CaB Candor Sand
4.25
100%
A/D Ra Rains Sandy Loam
0.00
0%
Existing Land Uses:
Land Use Description Existing Soil Group Acres
Curve #
Weighted CN
Open Space - Good Stand A 4.25
55
55.0
Cumulative Curve # =
55.0

Triangle Site Design, PLLC
Timberland Ranch, Hoke County, NC
Curve Number Calculation (CN)
Post -Developed Conditions to Infiltration Trench #4
Drainage Area (acres)• 4.25
Exisiinr,�Soil Groups
Soil Grout/ Man Symbol Soil Description
Acres
Percent of DA
A AuA Autryville Loamy Sand
0.00
0%
A CaB Candor Sand
4.25
100%
A/D Ra Rains Sandy Loam
0.00
0%
Proposed Land Uses:
Land Use Description Existing Soil Group Acres
Curve #
Wer�ghled CN
Impervious Area -Residential Lots A 2.20
98
50.7
Impervious Area-Sidewalk/Road A 0.49
98
11.3
Open Space - Good Condition A 1.56
55
20.2
Cumulative Curve # =
82.2

Infiltration Trench Design
Site Information
Sub Area Location:
Drainage To Infiltration Trench 4
Drainage Area (DA) =
4.25 Acres 185040 sf
Impervious Area (IA) =
2.69 Acres 117141 sf
Percent Impervious 11% _
_ 63.3 %
Required Water Quality Volume
Design Storm = 1 inch
Determine Rv Value = 0.05 + .009 (1) = 0.62 in/in
Water Quality Volume = 0.219 ac-ft
Water Quality Volume = 9,557 cf
Water Quality Volume = 0.620 inches of runoff
NOAA 1- ear. 24-hour event = 3 05 inches
Minimum Surface Area (SA)
SA = (12-FS-DV)/(K"T)
Factor of Safety (FS) =
2
Design Volume (DV) =
9556.6 cf
Hydraulic Conductivity of Soil =
43.00 in/hr
Max Dewatering Time =
72 hours
SA Required =
74.1 sf
SA Provided =
1170 sf

i
r—
.
1
I
I
!
1
1
I
'

-STAGEZSTORAGE
TABLE
STAGE
ELEVATION
CONTOUR
_
INCREMENTAL
TOTAL
(FT)
(FT)
AREA (SF)
STORAGE (CF)
STORAGE (CF)
0.0
384.0
1170
0
0
1.0
385.0
2480
1825
1825
2.0
386.0
3930
3205
5030
3.0
387.0
5850
4890
9920 (WOv)
4.0
388.0
9010
7430
17350
STORMWATER MANAGEMENT
INFILTRATION TRENCH #4
RIVER BASIN: CAPE FEAR
RECEIVING STREAM: WILL CREEK
STREAM INDEX: 18-31-11
STREAK CLASS: C
HUC: 03030004
DESIGN
DRAINAGE AREA TO SCM: 4.25 ACRES
SITE IMPERVIOUS AREA TO SCM: 2.69 ACRES
OFF -SITE DESIGN IMPERVIOUS AREA TO SCM: 0.00 ACRES
TOTAL DESIGN IMPERVIOUS AREA TO SCM: 2.69 ACRES
PRE -DEVELOPED POST -DEVELOPED POST DEVELOPED
TO SCM TO SCM THROUGH SLM
DRAINAGE AREA: 4.25 AC 4.25 AC
CURVE NUMBER: 55 82.2
TIME OF CONCENTRATION: 25 MIN 5 MIN
1-YEAR STORM EVENT:
0.272 CFS
10.26 CFS
0.000 CFS
2-YEAR STORM EVENT:
0.919 CFS
13.98 CFS
0.000 CFS
10-YEAR STORM EVENT:
4.197 CFS
24.62 CFS
0.000 CFS

i
I
i
-
.-
i
Z
O
I'-C NIN f
~
— UNDISTURBED'
W
IN -SITU SOIL
I1
�
l
a
_ -
i—
d
Z
_
G L
p
N
1 O
O
¢
d Z
yU�
< i
X
W�
i
s
- ?�`a
3cW
•�
J
H
0
d330 ,0I < 3MHS

Pond Report
5
Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2009 by Autodesk, Inc. v6.066 Wednesday, Jan 13, 2021
Pond No. 1 - BMP Pond
Pond Data
Contours - User -defined contour areas. Average end area method used for volume calculation. Begining Elevation = 384.00 ft
Stage / Storage Table
Stage (ft)
Elevation (ft)
Contour area (sgft)
Incr. Storage (cuft)
Total storage (cuft)
0.00
384.00
1,170
0
0
1.00
385.00
2,480
1,825
1,825
2.00
386.00
3,930
3,205
5,030
3.00
387.00
5,850
4,890
9,920
4.00
388.00
9,010
7,430
17,350
Culvert I Orifice Structures
Weir Structures
[A]
[B]
[C]
[PrfRsr]
[A] [B]
[C]
[D]
Rise (in)
Inactive
Inactive
Inactive
Inactive
Crest Len (ft)
= 0.00 0.00
0.00
000
Span (in)
= 0.00
0.00
0.00
0.00
Crest El. (ft)
= 0.00 0.00
0.00
0.00
No. Barrels
= 0
0
1
0
Weir Coeff.
= 2.60 333
3.33
3.33
Invert El. (ft)
= 0.00
0.00
0.00
0.00
Weir Type
= Broad ---
---
---
Length (ft)
= 0.00
0.00
0.00
0.00
Multi -Stage
= No No
No
No
Slope (%)
= 0.00
0.00
0.00
n/a
N-Value
= 013
.013
013
n/a
Orifice Coeff.
= 0.60
0.60
0.60
0.60
Exfil.(inlhr)
= 43.000 (by Contour)
Multi -Stage
= n/a
No
Yes
No
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 (ft)
4.00
3.00
2.00
1.00
0.00
0.00 1.00
Total Q
Stage / Discharge
2.00 3.00 4.00 5.00 6.00 7.00 8.00
Elev (ft)
388.00
387.00
386.00
385.00
384.00
9.00
Discharge (cfs)

1
Hydrograph Summary Re I?yTc raf ow Hydrographs Extension forAutoCAD® Civil 3130 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
0.272
2
740
3,155
2
SCS Runoff
10.26
2
718
20,711
3
Reservoir
0.000
2
766
0
______ BMP Pre -Developed
BMP Post -Developed
2 386.05 5,208 Post Through Pond
Infiltration Trench#4.gpw Return Period: 1 Year 1 Wednesday, Jan 13, 2021

Hydrograph Report
2
Hydraflow Hydrographs Extension forAutoCAD® Civil 3D® 2009 byAutodesk, Inc. v6.066
Hyd. No. 1
BMP Pre -Developed
Hydrograph type =
SCS Runoff
Storm frequency =
1 yrs
Time interval =
2 min
Drainage area =
4.250 ac
Basin Slope =
0.0 %
Tc method =
USER
Total precip. =
3.05 in
Storm duration =
24 hrs
BMP Pre -Developed
Wednesday, Jan 13, 2021
Peak discharge = 0.272 cfs
Time to peak
= 740 min
Hyd. volume
= 3,155 cuft
Curve number
= 55
Hydraulic length
= 0 ft
Time of conc. (Tc)
= 25.00 min
Distribution
= Type II
Shape factor
= 484
Q (cfs) Q (cfs)
Hyd. No. 1 -- 1 Year
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 - t - - 0.00
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Time (min)
Hyd No. 1

Hydrograph Report
3
Hydraflow Hydrographs Extension for AutoCADO Civil 31DO 2009 byAutodesk, Inc. v6.066
Hyd. No. 2
BMP Post -Developed
Hydrograph type =
SCS Runoff
Storm frequency =
1 yrs
Time interval =
2 min
Drainage area
4.250 ac
Basin Slope -
0.0 %
Tc method =
USER
Total precip. -
3.05 in
Storm duration -
24 hrs
Q (cfs)
12.00
10.00
M. M
. M
4.00
2.00
BMP Post -Developed
Hyd. No. 2 -- 1 Year
Wednesday, Jan 13, 2021
Peak discharge = 10.26 cfs
Time to peak
= 718 min
Hyd. volume
= 20,711 cuft
Curve number
= 82.2
Hydraulic length
= 0 ft
Time of conc. (Tc)
= 5.00 min
Distribution
= Type II
Shape factor
= 484
Q (cfs)
12.00
10.00
&O
II 1
4.00
2.00
0.00
120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Hyd No. 2 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 - BMP Post -Developed
Reservoir name = BMP Pond
Storage Indication method used. Exfiltration extracted from Outflow.
Q (cfs)
12.00
10.00
1
M
4.00
2.00
Post Through Pond
Hyd. No. 3 -- 1 Year
Wednesday, Jan 13, 2021
Peak discharge = 0.000 cfs
Time to peak
= 766 min
Hyd. volume
= 0 cuft
Max. Elevation
= 386.05 ft
Max. Storage
= 5,208 cuft
Q (cfs)
12.00
10.00
M
M
4.00
2.00
0.00
120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Time (min)
Hyd No. 3 Hyd No. 2 Total storage used = 5,208 cuft

iH yd rog ra p h Summary Re Pyaraf ow Hydrographs Extension for AutoCAD® Civil 3130 2009 by Autodesk, Inc. v6.066

Hydrograph Report
7
Hydraflow Hydrographs Extension forAutoCAD® Civil 3D®2009 by Autodesk, Inc. v6.066
Hyd. No. 1
BMP Pre -Developed
Hydrograph type =
SCS Runoff
Storm frequency =
2 yrs
Time interval =
2 min
Drainage area =
4.250 ac
Basin Slope =
0.0 %
Tc method =
USER
Total precip. =
3.69 in
Storm duration =
24 hrs
BMP Pre -Developed
Wednesday, Jan 13, 2021
Peak discharge = 0.919 cfs
Time to peak
= 732 min
Hyd. volume
= 6,253 cuft
Curve number
= 55
Hydraulic length
= 0 ft
Time of conc. (Tc)
= 25.00 min
Distribution
= Type II
Shape factor
= 484
Q (cfs) Q (cfs)
Hyd. No. 1 -- 2 Year
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. 1 Time (min)

Hydrograph Report
8
Hydraflow Hydrographs Extension forAutoCAD® Civil 31D® 2009 byAutodesk, Inc. v6.066
Hyd. No. 2
BMP Post -Developed
Hydrograph type =
SCS Runoff
Storm frequency =
2 yrs
Time interval =
2 min
Drainage area =
4.250 ac
Basin Slope =
0.0 %
Tc method =
USER
Total precip. =
3.69 in
Storm duration =
24 hrs
Q (cfs)
14.00
12.00
10.00
M
MM
4.00
M III 1
BMP Post -Developed
Hyd. No. 2 -- 2 Year
Wednesday, Jan 13, 2021
Peak discharge = 13.98 cfs
Time to peak
= 716 min
Hyd. volume
= 28,294 cuft
Curve number
= 82.2
Hydraulic length
= 0 ft
Time of conc. (Tc)
= 5.00 min
Distribution
= Type II
Shape factor
= 484
Q (cfs)
14.00
12.00
10.00
e
we]
i M
2.00
0.00
120 240 360 480 600 720 840 960 1080 1200 1320 1440
Hyd No. 2 Time (min)

Hydrograph Report
9
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. Exfiltration extracted from Outflow
Q (cfs)
14.00
12.00
10.00
A UR
.IX
4.00
2.00
Post Through Pond
Hyd. No. 3 -- 2 Year
Wednesday, Jan 13, 2021
Peak discharge = 0.000 cfs
Time to peak
= 704 min
Hyd. volume
= 0 cult
Max. Elevation
= 386.55 ft
Max. Storage
= 7,656 cuft
Q (cfs)
14.00
12.00
10.00
: el
N. 11
4.00
2.00
0.00
120 240 360 480 600 720 840 960 1080 1200 1320
Hyd No. 3 Hyd No. 2 Total storage used = 7,656 cult Time (min)

10
Hydrograph Summary Re Ry9ra-fiow Hydrographs Extension for AutoCAD® Civil 31302009 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) (cuft) (ft) (cuft)
1 SCS Runoff 4.197
2 SCS Runoff 24.62
3 Reservoir 0.000
2 730 18,412
2 716 50,684
2 740 0
2
387.70
BMP Pre -Developed
------ BMP Post -Developed
15,049 Post Through Pond
Infiltration Trench#4.gpw j Return Period: 10 Year Wednesday, Jan 13, 2021

Hydrograph Report
11
Hydraflow Hydrographs Extension forAutoCAD® Civil 3DO 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 =
4.250 ac
Basin Slope =
0.0 %
Tc method =
USER
Total precip. =
5.45 in
Storm duration =
24 hrs
Q (cfs)
5.00
4.00
Q 11
2.00
1.00
0.00
0 120 240
Hyd No. 1
BMP Pre -Developed
Hyd. No. 1 -- 10 Year
360 480 600 720 840
Wednesday, Jan 13, 2021
Peak discharge = 4.197 cfs
Time to peak
= 730 min
Hyd. volume
= 18,412 cuft
Curve number
= 55
Hydraulic length
= 0 ft
Time of conc. (Tc)
= 25.00 min
Distribution
= Type II
Shape factor
= 484
Q (cfs)
5.00
4.00
3.00
1.00
0.00
960 1080 1200 1320 1440 1560
Time (min)

Hydrograph Report
12
Hydraflow Hydrographs Extension forAutoCAD® Civil 3D® 2009 byAutodesk, Inc. v6.066
Hyd. No. 2
BMP Post -Developed
Hydrograph type =
SCS Runoff
Storm frequency =
10 yrs
Time interval =
2 min
Drainage area =
4.250 ac
Basin Slope =
0.0 %
Tc method =
USER
Total precip. =
5.45 in
Storm duration =
24 hrs
Q (cfs)
28.00
24.00
20.00
16.00
12.00
M
4.00
M
BMP Post -Developed
Hyd. No. 2 -- 10 Year
Wednesday, Jan 13, 2021
Peak discharge = 24.62 cfs
Time to peak =
716 min
Hyd. volume =
50,684 cuft
Curve number =
82.2
Hydraulic length
= 0 ft
Time of conc. (Tc)
= 5.00 min
Distribution
= Type II
Shape factor
= 484
Q (cfs)
28.00
24.00
20.00
16.00
12.00
M
4.00
0.00
120 240 360 480 600 720 840 960 1080 1200 1320
Hyd No. 2 Time (min)

13
Hydrograph Report
Hydraflow Hydrographs Extension forAutoCAD® Civil 3DO 2009 by Autodesk, Inc v6.066
Wednesday, Jan 13, 2021
Hyd. No. 3
Post Through Pond
Hydrograph type =
Reservoir
Peak discharge
= 0.000 cfs
Storm frequency =
10 yrs
Time to peak
= 740 min
Time interval =
2 min
Hyd. volume
= 0 cuft
Inflow hyd. No. =
2 - BMP Post -Developed
Max. Elevation
= 387.70 ft
Reservoir name =
BMP Pond
Max. Storage
= 15,049 cuft
Storage Indication method used. Exfiltration extracted from Outflow.
Q (cfs)
28.00
24.00
20.00
16.00
12.00
M
M
we
Post Through Pond
Hyd. No. 3 -- 10 Year
Q (cfs)
28.00
24.00
20.00
16.00
12.00
H-118ill
4.00
0.00
120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Time (min)
Hyd No. 3 Hyd No. 2 Total storage used = 15,049 cult

£$
§
4 ƒ!
2
>)
}#
|
2
�+
■
|<
|
F|
!
!
�R
a/
.
! |
a
([ §|
■
■] fit.
|
■� �!�
_
e(
a
■
|y
�
$q!
!»z
.|�
f��
!
|
R
� k
■
|!
§kf
2
k
�9|
.
§\§
�
�
§

7P(Ck,J :�Z4-tl

INFILTRATION TRENCH #5

`N cn, n cc; e Arecl,

Triangle Site Design, PLLC
Timberland Ranch, Hoke County, NC
Curve Number Calculation (CN)
Pre -Developed Conditions #5
Drainage Area 62 resZ 2.20
Existin4 Sail Groups
Soil Groua Map Symbol Soil Description
Acres
Percent of DA
A AuA Autryville Loamy Sand
0.00
0%
A CaB Candor Sand
2.20
100%
A/D Ra Rains Sandy Loam
0.00
0%
Eaistiii Land Uses:
Land Use Description Existinq Soil Group Acres
Curve #
Weighted CN
Open Space - Good Stand A 2.20
55
55.0
Cumulative Curve # =
55.0

Triangle Site Design, PLLC
Timberland Ranch, Hoke County, NC
Curve Number Calculation (CN)
Post -Developed Conditions to Infiltration Trench #5
Drainage Area (acres): 2.20
Existing Soil Groups:
Soil Group Map Symbol Soil Description
Acres
Percent of DA
A AuA Autryville Loamy Sand
0.00
0%
A CaB Candor Sand
2.20
100%
A/D Ra Rains Sandy Loam
0.00
0%
Proposed Land Uses:
Land Use Description Existing Soil Group Acres
Curve #
W_ e_ighted CN
Impervious Area -Residential Lots A 1.66
98
73.9
Impervious Area-Sidewalk/Road A 0.22
98
9.8
Open Space - Good Condition A 0.32
55
8.0
Cumulative Curve # =
91.7

Infiltration Trench ❑esion
Site Information
Sub Area Location: Drainage To Infiltration Trench 5
Drainage Area (DA) = 2.20 Acres 96006 sf
Impervious Area (IA) = 1.88 Acres 81698 sf
Percent Impervious (1) = 85.1 %
Required Water Quality Volume
Design Storm = t inch
Determine Rv Value = 0.05 + .009 (1) = 0.82 in/in
Water Quality Volume = 0.150 ac-ft
Water Quality Volume = 6,527 cf
Water Quality Volume = 0.816 inches of runoff
IJOAA 1- ear, 24-hour evenl = 3.05 inches
Minimum Surface Area (SA)
SA = (12-FS-DV)/(K-T)
Factor of Safety (FS) =
2
Design Volume (DV) =
6527.4 cf
Hydraulic Conductivity of Soil =
5.50 in/hr
Max Dewatering Time =
72 hours
SA Required =
395.6 sf
SA Provided =
1115 sf

(-S--TAGE/STORAGE
TABLE
STAGE
ELEVATION
CONTOUR
INCREMENTAL
TOTAL
(FT)
(FT)
AREA (SF)
STORAGE (CF)
STORAGE (CF)
0.0
384.0
1115
0
0
1.0
385.0
2330
1723
1723
2.0
386.0
3645
2988
4710
3.0
387.0
5000
4323
9033 (WQv)
4.0
388.0
6415
5708
14740
5.0
389.0
7885
7150
21890
STORMWATER MANAGEMENT DESIGN
INFILTRATION TRENCH #5
RIVER BASIN: LUMBER
RECEIVING STREAM: BUFFALO CREEK
STREAM INDEX: 14-2.5
STREAM CLASS: C
HUC: 03040203
SCM DESIGN SUMMARY
DRAINAGE AREA TO SCM: 2.20 ACRES
SITE IMPERVIOUS AREA TO SCM: 1.88 ACRES
OFF -SITE DESIGN IMPERVIOUS AREA TO SCM: 0.00 ACRES
TOTAL DESIGN IMPERVIOUS AREA TO SCM: 1.88 ACRES
PRE -DEVELOPED POST -DEVELOPED POST DEVELOPED
TO SCM TO SCM THROUGH SCM
DRAINAGE AREA: 2.20 AC 2.20 AC
CURVE NUMBER: 55 91.7
TIME OF CONCENTRATION: 21 MIN 5 MIN
1-YEAR STORM
EVENT:
0.151 CFS
7.779 CFS
0.000 CFS
2-YEAR STORM
EVENT:
0.525 CFS
9.808 CFS
0.000 CFS
10-YEAR STORM
EVENT:
2.404 CFS
15.34 CFS
0.000 CFS

12
e
lip
4
2
am ,m < M"
I
N

Pond Report 5
Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2009 by Autodesk, Inc. v6.066 Wednesday, Jan 13, 2021
Pond No. 1 - BMP Pond
Pond Data
Contours - User -defined contour areas. Average end area method used for volume calculation. Begining Elevation = 384.00 ft
Stage / Storage Table
Stage (ft)
Elevation (ft)
Contour area (sgft)
Incr. Storage (cult)
Total storage (cult)
0.00
384.00
1,115
0
0
1.00
385.00
2,330
1,723
1,723
2.00
386.00
3,645
2,988
4,710
3.00
387.00
5,000
4,323
9,033
4.00
388.00
6,415
5,708
14,740
5.00
389.00
7,885
7,150
21,890
Culvert / Orifice
Structures
Weir Structures
[A]
[Bl
[C]
[PrfRsr]
[A] IBl
[C]
[D]
Rise (in)
Inactive
Inactive
Inactive
Inactive
Crest Len (ft)
= 0.00 0.00
0.00
0.00
Span (in)
= 0.00
0.00
0.00
0.00
Crest El. (ft)
= 0.00 0.00
0.00
0.00
No. Barrels
= 0
0
1
0
Weir Coeff.
= 2.60 3.33
3.33
3.33
Invert El. (ft)
= 0.00
0.00
0.00
0.00
Weir Type
= Broad ---
---
---
Length (ft)
= 0.00
0.00
0.00
0.00
Multi -Stage
= No No
No
No
Slope (%)
= 0.00
000
0.00
n/a
N-Value
= .013
.013
.013
n/a
Orifice Coeff.
= 0.60
0.60
0.60
0.60
Exfil.(in/hr)
= 5.500 (by Contour)
Multi -Stage
= n/a
No
Yes
No
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 (ft)
5 00
4.00
3.00
2.00
1.00
0.00
0.00
Total Q
0.50
Stage / Discharge
1.00
1.50
Elev (ft)
389.00
388.00
387.00
386.00
385.00
384.00
2.00
Discharge (cfs)

H yd rog ra p h Summary Re Ryar"flow Hydrographs Extension for AutoCAD® Civil 3D® 2009 by Autodesk, Inc. v6.066
Hydrograph
description
MP Pre -Developed
MP Post -Developed
ost Through Pond
Jan 13, 2021

Hydrograph Report
2
Hydraflow Hydrographs Extension forAutoCAD® Civil 31>0 2009 byAutodesk, Inc. v6.066
Hyd. No. 1
BMP Pre -Developed
Hydrograph type =
SCS Runoff
Storm frequency =
1 yrs
Time interval =
2 min
Drainage area =
2.200 ac
Basin Slope =
0.0 %
Tc method =
USER
Total precip. =
3.05 in
Storm duration =
24 hrs
BMP Pre -Developed
Wednesday, Jan 13, 2021
Peak discharge = 0.151 cfs
Time to peak =
738 min
Hyd. volume =
1,688 cuft
Curve number =
55
Hydraulic length =
0 ft
Time of conc. (Tc) =
21.00 min
Distribution =
Type II
Shape factor =
484
Q (cfs) Q (cfs)
Hyd. No. 1 -- 1 Year
0.50 0.50
0.45 -- - 0.45
I
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 - .- -L 0.00
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Hyd No. 1 Time (min)

Hydrograph Report
3
Hydraflow Hydrographs Extension forAutoCAD® Civil 3DO 2009 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 =
2.200 ac
Basin Slope =
0.0 %
Tc method =
USER
Total precip. =
3.05 in
Storm duration =
24 hrs
M. 10
4.00
2.00
Wednesday, Jan 13, 2021
Peak discharge = 7.779 cfs
Time to peak
= 716 min
Hyd. volume
= 16,328 cuft
Curve number
= 91.7
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)
8.00
4.00
2.00
0.00
1080 1200 1320
Time (min)

Hydrograph Report
4
Hydraflow Hydrographs Extension forAutoCAD@ 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 - BMP Post -Developed
Reservoir name = BMP Pond
Storage Indication method used. Exfiltration extracted from Outflow.
Q (cfs)
M
4.00
2.00
Post Through Pond
Hyd. No. 3 -- 1 Year
Peak discharge
Time to peak
Hyd. volume
Max. Elevation
Max. Storage
Wednesday, Jan 13, 2021
= 0.000 cfs
898 min
= 0 cuft
= 386.75 ft
= 7,961 cuft
Q (cfs)
8.00
. IX
4.00
2.00
0.00
120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560 1680 1800
Hyd No. 3 Hyd No. 2 Total storage used = 7,961 cuft Time (min)

Hy
Hyd.
No.
1
2
3
d rog ra p h Summary Re Piyar f�iow Hydrographs Extension for AutoCAD® Civil 3D® 2009 by Autodesk, Inc. v6.066
Hydrograph Peak Time Time to Hyd. Inflow Maximum Total Hydrograph
type flow interval peak volume hyd(s) elevation strge used description
(origin) (cfs) (min) (min) (cuft) (ft) (cuft)
SCS Runoff 0.525 2 730 3,347 - ------ -- BMP Pre -Developed
SCS Runoff 9.808 2 716 20,884 — - ------ BMP Post -Developed
Reservoir 0.000 2 I 1012 0 2 387.24 10,393 Post Through Pond
Infiltration Trench#5.gpw Return Period: 2 Year Wednesday, Jan 13, 2021

Hydrograph Report
7
Hydraflow Hydrographs Extension forAutoCAD® Civil 31302009 by Autodesk, Inc. v6.066
Hyd. No. 1
BMP Pre -Developed
Hydrograph type =
SCS Runoff
Storm frequency =
2 yrs
Time interval =
2 min
Drainage area =
2.200 ac
Basin Slope =
0.0 %
Tc method =
USER
Total precip. =
3.69 in
Storm duration =
24 hrs
BMP Pre -Developed
Wednesday, Jan 13, 2021
Peak discharge = 0.525 cfs
Time to peak
= 730 min
Hyd. volume
= 3,347 cuft
Curve number
= 55
Hydraulic length
= 0 ft
Time of conc. (Tc)
= 21.00 min
Distribution
= Type II
Shape factor
= 484
Q (cfs) Hyd. No. 1 -- 2 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
0.00 - - - - — — __ - 0.00
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Hyd No. 1 Time (min)

IHydrograph Report
8
Hydraflow Hydrographs Extension forAutoCAD® Civil 3DO 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 =
2.200 ac
Basin Slope =
0.0 %
Tc method =
USER
Total precip. =
3.69 in
Storm duration =
24 hrs
AM
4.00
2.00
0.00
0 120
Hyd No. 2
BMP Post -Developed
Hyd. No. 2 -- 2 Year
Wednesday, Jan 13, 2021
Peak discharge = 9.808 cfs
Time to peak
= 716 min
Hyd. volume
= 20,884 cuft
Curve number
91.7
Hydraulic length
0 ft
Time of conc. (Tc)
= 5.00 min
Distribution
= Type II
Shape factor
484
240 360 480 600 720 840
Q (cfs)
10.00
M
. �M
4.00
wir
0.00
960 1080 1200
Time (min)

t±,
Hydrograph Report
Hydraflow Hydrographs Extension for AutoCADD Civil 31302009 byAutodesk, Inc. v6.066
Wednesday, Jan 13, 2021
Hyd. No. 3
Post Through Pond
Hydrograph type =
Reservoir
Peak discharge
= 0.000 cfs
Storm frequency =
2 yrs
Time to peak
= 1012 min
Time interval =
2 min
Hyd. volume
= 0 cult
Inflow hyd. No. =
2 - BMP Post -Developed
Max. Elevation
= 387.24 ft
Reservoir name =
BMP Pond
Max. Storage
= 10,393 cuft
Storage Indication method used. Exfiltration extracted from Outflow.
Q (cfs)
10.00
MIX
. We
4.00
C
Post Through Pond
Hyd. No. 3 -- 2 Year
120 240 360 480 600
Hyd No. 3 Hyd No. 2
Q (cfs)
10.00
GH
ok
4.00
2.00
0.00
720 840 960 1080 1200 1320 1440 1560 1680
Time (min)
Total storage used = 10,393 cult

10
Hydrograph Sumr
Hyd.
Hydrograph
Peak Time
No.
type
flow interval
(origin)
SCS Runoff
(cfs) (min)
2.404 2
1
2
SCS Runoff
15.34 2
3
Reservoir
0.000 2
Infiltration Trench#5.gpw
nary Re RQra-flow Hydrographs Extension forAutoCAD® Civil 3D® 2009 by Autodesk, Inc. v6.066
Time to
Hyd. '
Inflow
Maximum
Total
Hydrograph
peak
volume
hyd(s)
elevation
strge used
description
(min)
(cuft)
i
(ft)
(cuft)
—
------
728
9,855
BMP Pre -Developed
716
33,665
------
------
------
BMP Post -Developed
728
0
2
388.37
17,381
Post Through Pond
.L >
Return Period: 10 Year
Wednesday, Jan 13, 2021

Hydrograph Report
11
Hydraflow Hydrographs Extension forAutoCAD® 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 =
2.200 ac
Basin Slope =
0.0 %
Tc method =
USER
Total precip. =
5.45 in
Storm duration =
24 hrs
Q (cfs)
3.00
2.00
1.00
BMP Pre -Developed
Hyd. No. 1 -- 10 Year
120 240 360 480 600 720 840 960
Hyd No. 1
Wednesday, Jan 13, 2021
Peak discharge = 2.404 cfs
Time to peak =
728 min
Hyd. volume =
9,855 cuft
Curve number =
55
Hydraulic length =
0 ft
Time of conc. (Tc)
= 21.00 min
Distribution
= Type II
Shape factor
= 484
Q (cfs)
3.00
2.00
1.00
0.00
1080 1200 1320 1440 1560
Time (min)

Hydrograph Report
iV
Hydraflow Hydrographs Extension forAutoCAD® Civil 31302009 by Autodesk, Inc. v6.066
Hyd. No. 2
BMP Post -Developed
Hydrograph type =
SCS Runoff
Storm frequency =
10 yrs
Time interval =
2 min
Drainage area =
2.200 ac
Basin Slope =
0.0 %
Tc method =
USER
Total precip. =
5.45 in
Storm duration =
24 hrs
BMP Post -Developed
Hyd. No. 2 -- 10 Year
15.00
12.00
• Q
M. Me
3.00
Wednesday, Jan 13, 2021
Peak discharge = 15.34 cfs
Time to peak
= 716 min
Hyd. volume
= 33,665 cuft
Curve number
= 91.7
Hydraulic length
= 0 ft
Time of conc. (Tc)
= 5.00 min
Distribution
= Type II
Shape factor
= 484
Q (cfs)
18.00
15.00
12.00
• 11
WE
3.00
0.00 -1— - ' ' — - 0.00
0 120 240 360 480 600 720 840 960 1080 1200
Hyd No. 2 Time (min)

Hydrograph Report
13
Hydraflow Hydrographs Extension for AutoCADD Civil 3D® 2009 byAutodesk, Inc. v6.066
Hyd. No. 3
Post Through Pond
Hydrograph type = Reservoir
Storm frequency = 10 yrs
Time interval = 2 min
Inflow hyd. No. = 2 - BMP Post -Developed
Reservoir name = BMP Pond
Storage Indication method used. Exfiltration extracted from Outflow
Post Through Pond
Wednesday, Jan 13, 2021
Peak discharge = 0.000 cfs
Time to peak
= 728 min
Hyd. volume
= 0 cult
Max. Elevation
= 388.37 ft
Max. Storage
= 17,381 cuft
Q (cfs) Hyd. No. 3 -- 10 Year Q (cfs)
18.00 18.00
15.00 15.00
12.00 12.00
9.00 9.00
6.00 6.00
3.00 3.00
0.00 — — --_— —.L - - - 0.00
0 240 480 720 960 1200 1440 1680 1920
Time (min)
— Hyd No. 3 Hyd No. 2 Total storage used = 17,381 cult

\/
|
e!
�#
!
|
�©
i
|
�K
!
a !2!w
�f
§
i)
!
a§
!
I
■
(}
2
§|
§! ��_
■
�
■
�f}
�
!I!
■
}
2
(k
2
\!
� �#1
`}
■
)|
§|}
,
!
�

1 '�, A"2 O'- Cc C, -"A- . on

INFILTRATION TRENCH #6

I n-� I+fr,.41 C"-\ -1=1 ce
ry n
i�3�a�

Triangle Site Design, PLLC
Timberland Ranch, Hoke County, NC
Curve Number Calculation (CN)
Pre -Developed Conditions #6
Drainage Area (acresZ 1.33
Existing Soil Groups:
Soil Group Map Symbol Soil Description
Acres
Percent of DA
A AuA Autryville Loamy Sand
0.00
0%
A CaB Candor Sand
1.33
100%
A/D Ra Rains Sandy Loam
0.00
0%
Existing Land Uses:
Land Use Description Existing Soil Group Acres
Curve #
Weighted CN
Open Space - Good Stand A 1.33
55
55.0
Cumulative Curve # =
55.0

Triangle Site Design, PLLC
Timberland Ranch, Hoke County, NC
Curve Number Calculation (CN)
Post -Developed Conditions to Infiltration Trench *6
Drainage Area (acres): 1.33
Existing Soil Groups:
Soil Groua Map Symbol Soil Description
Acres
Percent of DA
A AuA Autryville Loamy Sand
0.00
0%
A CaB Candor Sand
1.33
100%
A/D Ra Rains Sandy Loam
0.00
0%
Proposed Land Uses:
Land Use Description Existing Soil Group Acres
Curve #
Weighted CN
Impervious Area -Residential Lots A 0.55
98
40.5
Impervious Area-Sidewalk/Road A 0.00
98
0.0
Open Space - Good Condition A 0.78
55
32.3
Cumulative Curve # =
72.8

Infiltration Trench Design
Site Information
Sub Area Location:
Drainage To Infiltration Trench 6
Drainage Area (DA) =
1.33 Acres 58006 sf
Impervious Area (IA) =
0.55 Acres 24000 sf
Percent Impervious (1) =
41.4 %
Required Water Quality Volume
Design Storm = inch
Determine Rv Value = 0.05 + .009 (1) = 0.42 in/in
Water Quality Volume = 0.047 ac-ft
Water Quality Volume = 2,042 cf
Water Qualitv Volume = 0.422 inches of runoff
NOAA 1- ear, 24-hour event = 3.05 inches
Minimum Surface Area (SA)
SA = (12"FS"DV)/(K•T)
Factor of Safety (FS) =
2
Design Volume (DV) =
2041.7 cf
Hydraulic Conductivity of Soil =
2.17 in/hr
Max Dewatering Time =
72 hours
SA Required =
313.6 sf
SA Provided =
530 sf

STAGE STORAGE TABLE
STAGE ELEVATION CONTOUR INCREMENTAL TOTAL
(FT) (FT) AREA (SF) STORAGE (CF) STORAGE (Cr)
0.0
380.0
530
0
0
1.0
381.0
1235
883
883
2.0
382.0
2005
1620
2503 (WQv)
3.0
383.0
2840
2423
4925
4.0
384.0
3740
3290
8215
STORMWATER MANAGEMENT
INFILTRATION TRENCH #6
RIVER BASIN: CAPE FEAR
RECEIVING STREAM: MILL CREEK
STREAM INDEX: 18-31-11
STREAM CLASS: C
HUC: 03030004
SUMMARY
DESIGN
DRAINAGE AREA TO SCM: 1.33 ACRES
SITE IMPERVIOUS AREA TO SCM: 0.55 ACRES
OFF -SITE DESIGN IMPERVIOUS AREA TO SCM: 0.00 ACRES
TOTAL DESIGN IMPERVIOUS AREA TO SCM: 0.55 ACRES
PRE -DEVELOPED POST -DEVELOPED POST DEVELOPED
TO SCM TO SCM THROUGH SCM
DRAINAGE AREA: 1.33 AC 1.33 AC
CURVE NUMBER: 55 72.8
TIME OF CONCENTRATION: 18 MIN 5 MIN
1-YEAR STORM EVENT:
0.098 CFS
1.969 CFS
0.000 CFS
2-YEAR STORM EVENT:
0.353 CFS
2.932 CFS
0.000 CFS
10-YEAR STORM EVENT:
1.607 CFS
5.874 CFS
0.000 CFS

R
to'
iM¢
z
0
YNFNSlWBAEG
�
Ill-YN SpC
U
Z Z
C
H
Z
0
H
Q
H
•
Z
5F
C
h
12
dJM .01 < MMIS
NIN.:
I

Pond Report s
Hydraflow Hydrographs Extension forAutoCAD® Civil 3D® 2009 by Autodesk, Inc. v6.066
Thursday, Jan 14, 2021
Pond No. 1
- BMP Pond
Pond Data
Contours - User
-defined contour areas.
Average end
area method used for volume calculation. Begining Elevation
= 380.00 ft
Stage / Storage Table
Stage (ft)
Elevation (ft)
Contour area (sqft)
Incr. Storage (cult) Total storage (cuft)
0.00
380.00
530
0 0
1.00
381.00
1,235
883 883
2.00
382.00
2,005
1,620 2,503
3.00
383.00
2.840
2,423 4,925
4.00
384.00
3.740
3,290 8,215
Culvert / Orifice
Structures
Weir Structures
[A►)
[B]
[C]
[PrfRsr]
[A►] [Bl
[C]
[D]
Rise (in)
Inactive
Inactive
Inactive
Inactive
Crest Len (ft) = 0.00 0.00
0.00
0.00
Span (in)
= 0.00
0.00
0.00
0.00
Crest El. (ft) = 000 0.00
0.00
0.00
No. Barrels
= 0
0
1
0
Weir Coeff. = 2.60 3.33
333
3.33
Invert El. (ft)
= 0.00
0.00
0.00
0.00
Weir Type = Broad ---
---
---
Length (ft)
= 0.00
0.00
0.00
0.00
Multi -Stage = No No
No
No
Slope (%)
= 0.00
0.00
0.00
n/a
N-Value
= .013
.013
.013
n/a
Orifice Coeff.
= 0.60
0.60
0.60
0.60
Exfil.(in/hr) = 2.170 (by Contour)
Multi -Stage
= n/a
No
Yes
No
TW Elev. (ft) = 0.00
Stage (ft)
4.00
3.00
2.00
1.00
0.00 t - I
0.00 0.02
Total Q
Note: Culvert/Orifice outflows are analyzed under inlet (ic) and outlet (oc) control. Weir risers checked for orifice conditions (ic) and submergence (s).
Stage I Discharge
0.04 0.06 0.08 0.10 0.12 0.14 0.16 0.18
Elev (ft)
384.00
383.00
382.00
381.00
380.00
0.20
Discharge (cfs)

I
H yd rog ra p h Summary Re pyq, flow Hydrographs Extension for AutoCAD® Civil 3D® 2009 by Autodesk, Inc. v6.066
Hyd. Hydrograph Peak Time
No. type 1 flow inter
(origin) (cfs) (mir
1 SCS Runoff
2 SCS Runoff
3 1 Reservoir
0.098 2
1.969 2
0.000 2
Infiltration Trench#6.gpw

Hydrograph Report
Hydraflow Hydrographs Extension forAutoCAD® Civil 31382009 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 =
1.330 ac
Basin Slope =
0.0 %
Tc method =
USER
Total precip. =
3.05 in
Storm duration = 24 hrs
BMP Pre -Developed
Thursday, Jan 14, 2021
Peak discharge = 0.098 cfs
Time to peak
= 732 min
Hyd. volume
= 1,003 cuft
Curve number
= 55
Hydraulic length
= 0 ft
Time of conc. (TO
= 18.00 min
Distribution
= Type II
Shape factor
= 484
Q (cfs) Hyd. No. 1 -- 1 Year 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 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. 1

Hydrograph Report
3
Hydraflow Hydrographs Extension forAutoCAD® Civil 3D® 2009 byAutodesk, Inc. v6.066
Hyd. No. 2
BMP Post -Developed
Hydrograph type =
SCS Runoff
Storm frequency =
1 yrs
Time interval =
2 min
Drainage area =
1.330 ac
Basin Slope =
0.0 %
Tc method =
USER
Total precip. =
3.05 in
Storm duration =
24 hrs
Q (cfs)
2.00
1.00
BMP Post -Developed
Hyd. No. 2 -- 1 Year
120 240 360 480 600 720 840
Hyd No. 2
Thursday, Jan 14, 2021
Peak discharge = 1.969 cfs
Time to peak
= 718 min
Hyd. volume
= 3,974 cuft
Curve number
= 72.8
Hydraulic length
= 0 ft
Time of conc. (Tc)
= 5.00 min
Distribution
= Type II
Shape factor
= 484
Q (cfs)
2.00
1.00
- 0.00
960 1080 1200 1320 1440 1560
Time (min)

Hydrograph Report
4
Hydraflow, Hydrographs Extension forAutoCAD® 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. Exfiltration extracted from Outflow
Q (cfs)
2.00
1.00
we
Post Through Pond
Hyd. No. 3 -- 1 Year
240 480 720 960
Hyd No. 3 Hyd No. 2
Peak discharge
Time to peak
Hyd. volume
Max. Elevation
Max. Storage
Thursday, Jan 14, 2021
= 0.000 cfs
= 1348 min
= 0 cuft
= 381.62 ft
= 1,889 cuft
1200 1440 1680 1920 2160
Total storage used = 1,889 cuft
Q (cfs)
2.00
1.00
- 0.00
2400
Time (min)

Hydrograph Summary Re PQra-floow Hydrographs Extension forAutoCAD® Civil 3138 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
0.353
2
728
1,988
------
------
Pre-Developed
FBMPP
2
SCS Runoff
2.932
2
718
5,868
-----
------
Post -Developed
3
Reservoir
0.000
2
734
0
Return Period:
2
2 Year
382.23
3,052
Thursday,
Post Through Pond
Jan 14, 2021
Infiltration
Trench#6.gpw

Hydrograph Report
7
Hydraflow Hydrographs Extension forAutoCAD® Civil 31302009 by Autodesk, Inc. v6.066
Hyd. No. 1
BMP Pre -Developed
Hydrograph type =
SCS Runoff
Storm frequency =
2 yrs
Time interval =
2 min
Drainage area =
1.330 ac
Basin Slope =
0.0 %
Tc method =
USER
Total precip. =
3.69 in
Storm duration =
24 hrs
BMP Pre -Developed
Thursday, Jan 14, 2021
Peak discharge = 0.353 cfs
Time to peak
= 728 min
Hyd. volume
= 1,988 cuft
Curve number
= 55
Hydraulic length
= 0 ft
Time of conc. (Tc)
= 18.00 min
Distribution
= Type II
Shape factor
= 484
Q (cfs) Q (cfs)
Hyd. No. 1 -- 2 Year
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)

Hydrograph Report
Hydraflow Hydrographs Extension forAutoCAD® Civil 3DO 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
= 1.330 ac
Basin Slope
= 0.0 %
Tc method
= USER
Total precip.
= 3.69 in
Storm duration
= 24 hrs
BMP Post -Developed
Q (cfs) Hyd. No. 2 -- 2 Year
3.00
M
1.00
M
120 240 360 480 600 720 840 960
Hyd No. 2
8
Thursday, Jan 14, 2021
Peak discharge = 2.932 cfs
Time to peak =
718 min
Hyd. volume =
5,868 cuft
Curve number =
72.8
Hydraulic length =
0 ft
Time of conc. (Tc) =
5.00 min
Distribution =
Type II
Shape factor =
484
Q (cfs)
3.00
2.00
1.00
0.00
1080 1200 1320 1440 1560
Time (min)

Hydrograph Report
9
Hydraflow Hydrographs Extension for AutoCADO Civil 3130 2009 by Autodesk, 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. Exfiltration extracted from Outflow
2.00
1.00
0.00
0 240
— Hyd No. 3
Post Through Pond
Hyd. No. 3 -- 2 Year
Peak discharge
Time to peak
Hyd. volume
Max. Elevation
Max. Storage
Thursday, Jan 14, 2021
= 0.000 cfs
= 734 min
= 0 cuft
= 382.23 ft
= 3,052 cuft
480 720 960 1200 1440 1680 1920 2160
Hyd No. 2 Total storage used = 3,052 cuft
Q (cfs)
3.00
2.00
1.00
0.00
2400
Time (min)

10
H yd rog ra p h Summary Re Py3ra�flow Hydrographs Extension forAutoCAD® Civil 31302009 by Autodesk, Inc. v6.066

Hydrograph (Report
11
Hydraflow Hydrographs Extension forAutoCAD® 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 =
1.330 ac
Basin Slope =
0.0 %
Tc method =
USER
Total precip. =
5.45 in
Storm duration =
24 hrs
Q (cfs)
2.00
1.00
BMP Pre -Developed
Hyd. No. 1 -- 10 Year
120 240 360 480 600 720 840 960
Hyd No. 1
Thursday, Jan 14, 2021
Peak discharge = 1.607 cfs
Time to peak
= 726 min
Hyd. volume
= 5,853 cuft
Curve number
= 55
Hydraulic length
= 0 ft
Time of conc. (Tc)
= 18.00 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 forAutoCAD® Civil 31D® 2009 by Autodesk, Inc. v6.066
Hyd. No. 2
BMP Post -Developed
Hydrograph type = SCS Runoff
Storm frequency = 10 yrs
Time interval
= 2 min
Drainage area
= 1.330 ac
Basin Slope
= 0.0 %
Tc method
= USER
Total precip.
= 5.45 in
Storm duration
= 24 hrs
5.00
4.00
3.00
2.00
1.00
we
BMP Post -Developed
Hyd. No. 2 -- 10 Year
12
Thursday, Jan 14, 2021
Peak discharge = 5.874 cfs
Time to peak
= 716 min
Hyd. volume
= 11,862 cuft
Curve number
= 72.8
Hydraulic length
= 0 ft
Time of conc. (Tc)
= 5.00 min
Distribution
= Type II
Shape factor
= 484
Q (cfs)
6.00
5.00
3.00
2.00
1.00
0.00
120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Hyd No. 2 Time (min)

Hydrograph Report
13
Hydraflow Hydrographs Extension forAutoCAD® Civil 3D® 2009 byAutodesk, Inc. v6.066
Hyd. No. 3
Post Through Pond
Hydrograph type = Reservoir
Storm frequency = 10 yrs
Time interval = 2 min
Inflow hyd. No. = 2 - BMP Post -Developed
Reservoir name = BMP Pond
Storage Indication method used. Exfiltration extracted from Outflow.
5.00
4.00
i 11
2.00
1.00
Post Through Pond
Hyd. No. 3 -- 10 Year
240 480 720 960
Hyd No. 3 Hyd No. 2
Thursday, Jan 14, 2021
Peak discharge = 0.000 cfs
Time to peak
= 1550 min
Hyd. volume
= 0 cuft
Max. Elevation
= 383.63 ft
Max. Storage
= 6,992 cuft
Q (cfs)
6.00
5.00
4.00
3.00
2.00
1.00
0.00
1200 1440 1680 1920 2160 2400 2640
Time (min)
Total storage used = 6,992 cult

|
`
_
.{
q
|
ƒf
[
!
!
2
�©
ir
k`
,® �t
£$
�
a2
�
al
k
#
;
■
)z
�
§|
|
$�;
■
_
CD
!
B|
k/t3
�
§
§

vi CJ/N

INFILTRATION TRENCH #7

a
sI
f
►1

Triangle Site Design, PLLC
Timberland Ranch, Hoke County, NC
Curve Number Calculation (CN)
Pre -Developed Conditions *7
Drainaae Area (acre4.18
Fxistin soil Grou s:
50ii Groua Map Symbol Soil Description Acres Percent of DA
A AuA Autryville Loamy Sand 0.00 0%
A CaB Candor Sand 4.18 100%
A/D Ra Rains Sandy Loam 0.00 0%
Existing Land Uses:
Land Use Description Existinq Soil Group Acres Curve # Weighted CN
Open Space - Good Stand A 4.18 55 55.0
Cumulative Curve # = 55.0

Triangle Site Design, PLLC
Timberland Ranch, Hoke County, NC
Curve Number Calculation (CN)
Post -Developed Conditions to Infiltration Trench #7
Drainage Area (acres): 4.18
Existino Soil Groups
Soii Grout/ Map Symbol Soil Description
Acres
Percent of DA
A AuA Autryville Loamy Sand
0.00
0%
A CaB Candor Sand
4.18
100%
A/D Ra Rains Sandy Loam
0.00
0%
Proaosed Land Uses:
Land Use Description Existing Soil Group. Acres
Curve #
Weighted CN
Impervious Area -Residential Lots A 2.76
98
64.7
Impervious Area-Sidewalk/Road A 0.32
98
7.5
Open Space - Good Condition A 1.10
55
14.5
Cumulative Curve # =
86.7

Infiltration Trench Desian
Site Information
Sub Area Location:
Drainage To Infiltration Trench 7
Drainage Area (DA) =
4.18 Acres 182260 sf
Impervious Area (IA) =
3.08 Acres 134033 sf
Percent Impervious (1) =
73.5 %
Required Water Quality Volume
Design Storm = 1 inch
Determine Rv Value = 0.05 + .009 (1) = 0.71 in/in
Water Quality Volume = 0.248 ac-ft
Water Quality Volume = 10,812 cf
Water Quality Volume = 0.712 inches of runoff
NQAA 1-yea r. 24-hour event = 3.05 inches
Minimum Surface Area (SA)
SA = (12"FS"DV)/(K"T)
Factor of Safety (FS) =
2
Design Volume (DV) =
10811.9 cf
Hydraulic Conductivity of Soil =
2.17 in/hr
Max Dewatering Time =
72 hours
SA Required =
1660.8 sf
SA Provided =
2355 sf

4�
��

'STAGE/STORAGE TABLE
STAGE ELEVATION CONTOUR INCREMENTAL TOTAL
(FT) (FT) AREA (SF) STORAGE (CF) STORAGE (CF)
0.0
383.0
2355
0
0
1.0
384.0
4450
3403
3403
2.0
385.0
6610
5530
8933
3.0
386.0
8890
7750
16683 (WQv)
4.0
387.0
11415
10153
26835
5.0
388.0
14320
12868
39703
STORMWATER MANAGEMENT DESIGN
INFILTRATION TRENCH #7
RIVER BASIN: LUMBER
RECEIVING STREAK: BUFFALO CREEK
STREAK INDEX: 14-2.5
STREAM CLASS: C
HUC: 03040203
SCM DESIGN SUMMARY
DRAINAGE AREA TO SCM: 4.18 ACRES
SITE IMPERVIOUS AREA TO SCM: 3.08 ACRES
OFF -SITE DESIGN US ARE6 TO 0.00 ACRES
TOTAL DESIGN IMPERVIOUS AREA TO SCM: 3.08 ACRES
PRE -DEVELOPED POST -DEVELOPED POST DEVELOPED
TO SCM TO SCK THROUGH SCM
DRAINAGE AREA: 4.18 AC 4.18 AC
CURVE NUMBER: 55 86.7
TIME OF CONCENTRATION: 23 MIN 5 MIN
1-YEAR STORM EVENT:
0.288 CFS
12.30 CFS
0.000 CFS
2-YEAR STORM EVENT:
0.998 CFS
16.13 CFS
0.000 CFS
10-YEAR STORM EVENT:
4.568 CFS
26.74 CFS
0.000 CFS

9
� IAI�ISIVPHEQ
� 3
p-vu 3611
U
x
j
4
it
u
All
951
V

Pond Report s
Hydraflow Hydrographs Extension forAutoCAD® Civil 3D® 2009 byAutodesk, Inc. v6.066
Thursday, Jan 14, 2021
Pond No. 1
- BMP Pond
Pond Data
Contours - User -defined contour areas.
Average end
area method used for volume calculation. Begining Elevation
= 383.00
ft
Stage / Storage Table
Stage (ft)
Elevation (ft)
Contour area (sgft)
Incr. Storage (cuft) Total storage (cuft)
0.00
383.00
2,355
0 0
1.00
384.00
4,450
3,403 3,403
2.00
385.00
6,610
5,530 8,933
3.00
386.00
8,890
7,750 16,683
4.00
387.00
11,415
10,153 26,835
5.00
388.00
14,320
12,868 39,703
Culvert I Orifice Structures
Weir Structures
[A]
[B]
[C]
[PrfRsr]
[A] [Bl
[C]
[D]
Rise (in)
Inactive
Inactive
Inactive
Inactive
Crest Len (ft) = 0.00 0.00
0.00
0.00
Span (in)
= 0.00
0.00
0.00
000
Crest El. (ft) = 0.00 0.00
0.00
0.00
No. Barrels
= 0
0
1
0
Weir Coeff. = 2.60 3.33
3.33
3.33
Invert El. (ft)
= 0.00
0.00
0.00
0.00
Weir Type = Broad ---
---
---
Length (ft)
= 0.00
0.00
0.00
0.00
Multi -Stage = No No
No
No
Slope (%)
= 0.00
0.00
0.00
n/a
N-Value
= .013
013
.013
n/a
Orifice Coeff.
= 0.60
0.60
0.60
0.60
Exfil.(in/hr) = 2.170 (by Contour)
Multi -Stage
= n/a
No
Yes
No
TW Elev. (ft) = 000
Stage (ft)
5.00
4.00
3.00
2.00
1.00
0.00
0.00 0.08
Total Q
Note: CulverUOriflce outflows are analyzed under inlet (ic) and outlet (oc) control Weir risers checked for orifice conditions (ic) and submergence (s)
Stage / Discharge
0.16 0.24 0.32 0.40 0.48 0.56 0.64 0.72
Elev (ft)
388.00
387.00
386.00
385.00
384.00
383.00
0.80
Discharge (cfs)

Hydrograph Summary Re Ryara-fiow Hydrographs Extension for AutoCAD® Civil 3DO 2009 by Autodesk, Inc. v6.066
Hyd.
No.
1
Hydrograph
type
(origin)
SCS Runoff
Peak
flow
(cfs)
0.288
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
2
738
3,208
------
2
SCS Runoff
12.30
2
716
25,027
-
-
------
BMP Post -Developed
3
Reservoir
0.000
2
680
0
2
385.74
14,629
Post Through Pond
Infiltration Trench#7.gpw
Return Period: 1 Year
Thursday, Jan 14, 2021

Hydrograph Report
Hydraflow Hydrographs Extension forAutoCAD® Civil 3D® 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
= 4.180 ac
Basin Slope
= 0.0 %
Tc method
= USER
Total precip.
= 3.05 in
Storm duration
= 24 hrs
BMP Pre -Developed
2
Thursday, Jan 14, 2021
Peak discharge = 0.288 cfs
Time to peak
= 738 min
Hyd. volume
= 3,208 cuft
Curve number
= 55
Hydraulic length
= 0 ft
Time of conc. (Tc)
= 23.00 min
Distribution
= Type II
Shape factor
= 484
Q (cfs) Q (cfs)
Hyd. No. 1 -- 1 Year
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)

Hydrograph Report
Hydraflow Hydrographs Extension forAutoCAD® Civil 3DO 2009 byAutodesk, Inc. v6.066
Hyd. No. 2
BMP Post -Developed
Hydrograph type = SCS Runoff
Storm frequency = 1 yrs
Time interval
= 2 min
Drainage area
= 4.180 ac
Basin Slope
= 0.0 %
Tc method
= USER
Total precip.
= 3.05 in
Storm duration
= 24 hrs
Q (cfs)
14.00
12.00
10.00
M
WE
4.00
2.00
BMP Post -Developed
Hyd. No. 2 -- 1 Year
K
Thursday, Jan 14, 2021
Peak discharge = 12.30 cfs
Time to peak =
716 min
Hyd. volume =
25,027 cuft
Curve number
= 86.7
Hydraulic length
= 0 ft
Time of conc. (Tc)
= 5.00 min
Distribution
= Type II
Shape factor
= 484
Q (cfs)
14.00
12.00
10.00
M
M
4.00
2.00
0.00 1 L I I - - - _.+- J J - 0.00
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440
Hyd No. 2 Time (min)

4
Hydrograph Report
Hydraflow Hydrographs Extension for AutoCAD® Civil 3DO 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. Exfiltration extracted from Outflow.
Post Through Pond
Thursday, Jan 14, 2021
Peak discharge = 0.000 cfs
Time to peak
= 680 min
Hyd. volume
= 0 cuft
Max. Elevation
= 385.74 ft
Max. Storage
= 14,629 cuft
Q (cfs) Hyd. No. 3 -- 1 Year Q (cfs)
14.00 14.00
12.00 12.00
10.00 10.00
8.00 8.00
6.00 6.00
4.00 4.00
2.00 2.00
0.00 - - 0.00
0 240 480 720 960 1200 1440 1680 1920 2160 2400 2640 2880 3120
Time (min)
Hyd No. 3 Hyd No. 2 Total storage used = 14,629 cult

Hyd rog ra p h Summary Re RQrlfllw Hydrographs Extension for AutoCAD® Civil 3130 2009 by Autodesk, Inc. v6.066

VA
Hydrograph Report
Hydraflow Hydrographs Extension forAutoCAD® Civil 3D® 2009 by Autodesk, Inc. v6.066
Hyd. No. 1
BMP Pre -Developed
Hydrograph type =
SCS Runoff
Storm frequency =
2 yrs
Time interval =
2 min
Drainage area =
4.180 ac
Basin Slope =
0.0 %
Tc method =
USER
Total precip. =
3.69 in
Storm duration = 24 hrs
BMP Pre -Developed
Thursday, Jan 14, 2021
Peak discharge = 0.998 cfs
Time to peak =
730 min
Hyd. volume =
6,360 cuft
Curve number =
55
Hydraulic length =
0 ft
Time of conc. (Tc)
= 23.00 min
Distribution
= Type II
Shape factor
= 484
Q (cfs) Q (cfs)
Hyd. No. 1 -- 2 Year
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
7_1
0.00 - — — - 0.00
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Hyd No. 1 Time (min)

8
Hydrograph Report
Hydraflow Hydrographs Extension forAutoCAD® Civil 3DO 2009 byAutodesk, Inc. v6.066
Hyd. No. 2
BMP Post -Developed
Hydrograph type =
SCS Runoff
Storm frequency =
2 yrs
Time interval =
2 min
Drainage area =
4.180 ac
Basin Slope =
0.0 %
Tc method =
USER
Total precip. =
3.69 in
Storm duration =
24 hrs
Q (cfs)
18.00
15.00
12.00
N. KIPTIM
3.00
BMP Post -Developed
Hyd. No. 2 -- 2 Year
Thursday, Jan 14, 2021
Peak discharge = 16.13 cfs
Time to peak
= 716 min
Hyd. volume
= 33,112 cuft
Curve number
= 86.7
Hydraulic length
= 0 ft
Time of conc. (Tc)
= 5.00 min
Distribution
= Type II
Shape factor
= 484
Q (cfs)
18.00
15.00
12.00
M
M
3.00
0.00 ���-�--� 0.00
0 120 240 360 480 600 720 840 960 1080 1200 1320
Hyd No. 2 Time (min)

9
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. Exfiltration extracted from Outflow
15.00
12.00
WE
M We
0.00
0 240 480
Hyd No. 3
Post Through Pond
Hyd. No. 3 -- 2 Year
Peak discharge
Time to peak
Hyd. volume
Max. Elevation
Max. Storage
Thursday, Jan 14, 2021
= 0.000 cfs
= 946 min
= 0 cult
= 386.33 ft
= 20,029 cuft
Q (cfs)
18.00
15.00
12.00
M
3.00
0.00
720 960 1200 1440 1680 1920 2160 2400 2640 2880
Hyd No. 2 Total storage used = 20,029 cult Time (min)

10
Hydrograph Summary Re Py9flow Hydrographs Extension forAutoCAD® Civil 3D® 2009 by Autodesk, Inc. v6.066
Hyd.
No.
Hydrograph
type
(origin)
Peak
flow
(cfs)
Time
interval
(min)
Time to
peak
(min)
Hyd.
volume
(cuft)
18,725
Inflow
hyd(s)
------
Maximum
elevation
(ft)
Total Hydrograph
strge used description
(cuft)
-- BMP Pre -Developed
1
SCS Runoff
4.568
2
728
-
2
SCS Runoff
26.74
2
716
56,354
--
-
BMP Post -Developed
3
Reservoir
0.000
2
784
0
2
387.70
35,905 Post Through Pond
Thursday, Jan 14, 2021
Infiltration
Trench#7.gpw
Return Period:
10
Year

11
Hydrograph Report
Hydraflow Hydrographs Extension forAutoCAD® 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
= 4.180 ac
Basin Slope
= 0.0 %
Tc method
= USER
Total precip.
= 5.45 in
Storm duration
= 24 hrs
Q (cfs)
5.00
4.00
3.00
2.00
1.00
0.00
0 120 240
Hyd No. 1
BMP Pre -Developed
Hyd. No. 1 -- 10 Year
360 480 600 720 840
Thursday, Jan 14, 2021
Peak discharge = 4.568 cfs
Time to peak
= 728 min
Hyd. volume
= 18,725 cuft
Curve number
= 55
Hydraulic length
= 0 ft
Time of conc. (Tc)
= 23.00 min
Distribution
= Type II
Shape factor
= 484
Q (cfs)
5.00
4.00
3.00
2.00
1.00
0.00
960 1080 1200 1320 1440 1560
Time (min)

Hurirnnranh Rannrt
12
Hydraflow Hydrographs Extension forAutoCAD® Civil 3D®2009 by Autodesk, Inc. v6.066
Hyd. No. 2
BMP Post -Developed
Hydrograph type = SCS Runoff
Storm frequency = 10 yrs
Time interval
= 2 min
Drainage area
= 4.180 ac
Basin Slope
= 0.0 %
Tc method
= USER
Total precip.
= 5.45 in
Storm duration
= 24 hrs
24.00
20.00
16.00
12.00
E
4.00
BMP Post -Developed
Hyd. No. 2 -- 10 Year
Thursday, Jan 14, 2021
Peak discharge = 26.74 cfs
Time to peak =
716 min
Hyd. volume =
56,354 cuft
Curve number =
86.7
Hydraulic length =
0 ft
Time of conc. (Tc)
= 5.00 min
Distribution
= Type II
Shape factor
= 484
Q (cfs)
28.00
24.00
20.00
16.00
12.00
M
4.00
0.00
120 240 360 480 600 720 840 960 1080 1200
Hyd No. 2 Time (min)

13
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 - BMP Post -Developed
Reservoir name = BMP Pond
Storage Indication method used. Exfiltration extracted from Outflow
Q (cfs)
28.00
24.00
20.00
16.00
12.00
4.00
0.00
0 360
Hyd No. 3
Post Through Pond
Hyd. No. 3 -- 10 Year
Thursday, Jan 14, 2021
Peak discharge = 0.000 cfs
Time to peak
= 784 min
Hyd. volume
= 0 cuft
Max. Elevation
= 387.70 ft
Max. Storage
= 35,905 cuft
720 1080 1440 1800 2160 2520 2880
Hyd No. 2 Total storage used = 35,905 cuft
Q (cfs)
28.00
24.00
r�9
16.00
12.00
M
4.00
0.00
3240
Time (min)

£/
§
| ƒF
2
�■
�!
!
2
k`
f
!
!«
!
■ k2lt
k §}q
§j))\|!
|}
!
i&
k
7 �
■
}� jk£
&
«
�
14
!
i|I
!
{�!
■
#
§
�
22
k
B
(�
,
�
& a»
■
� §©
0;|
|
§
�
�
|
�

INFILTRATION TRENCH #8

4,&3 ac-

Triangle Site Design, PLLC
Timberland Ranch, Hoke County, NC
Curve Number Calculation (CN)
Pre -Developed Conditions #8
Drainage Area (acresZ 4.63
Existing Soil Graups:
Soil Grow Map Symbol Soil Description
Acres
Percent of DA
A AuA Autryville Loamy Sand
0.00
0%
A CaB Candor Sand
4.63
100%
A/D Ra Rains Sandy Loam
0.00
0%
Existing Land lases:
Land Use Description Existing Soil Group Acres
Curve #
Weighted CN
Open Space - Good Stand A 4.63
55
55.0
Cumulative Curve # =
55.0

Triangle Site Design, PLLC
Timberland Ranch, Hoke County, NC
Curve Number Calculation (CN)
Post -Developed Conditions to Infiltration Trench #8
Drainage Area (acres]: 4.63
Existing Soil Getups
Soil GroUD Map Symbol Soil Description
Acres
Percent of DA
A AuA Autryville Loamy Sand
4.63
100%
A CaB Candor Sand
0.00
0%
A/D Ra Rains Sandy Loam
0.00
0%
ea2posed Land Uses:
Land Use Description Pxistinv Soil Group Acres
Curve #
Weighted CN
Impervious Area -Residential Lots A 3.45
98
73.0
Impervious Area-Sidewalk/Road A 0.39
98
8.3
Open Space - Good Condition A 0.79
55
9.4
Cumulative Curve # =
90.7

Infiltration Trench Design
Site Information
Sub Area Location:
Drainage To Infiltration Trench 7
Drainage Area (DA) =
4.63 Acres 201552 sf
Impervious Area (IA) =
3.84 Acres 167080 sf
Percent Impervious (1) =
82.9 %
Required Water Quality Volume
Design Storm =
1 inch
Determine Rv Value =
0.05 + .009 (1) = 0.80 in/in
Water Quality Volume =
0.307 ac-ft
Water Quality Volume =
13,371 cf
Water quality Volume =
0.796 inches of runoff
NOAA 1- ear, 24-hour event = 3.05 inches
Minimum Surface Area (
SA = (12-FS*DV)/(K-T)
Factor of Safety (FS) =
2
Design Volume (DV) =
13370.8 cf
Hydraulic Conductivity of Soil =
2.17 in/hr
Max Dewatering Time =
72 hours
SA Required =
2053.9 sf
SA Provided -
2375 sf

�
I
�
I
i
f
I
1
I
I
\ I
I
I
I
I
I I
I
I I
/
/
1
I !
I �
I
1

(t-TAGE/STORAGE
TABLE
STAGE
ELEVATION
CONTOUR
INCREMENTAL
TOTAL
(FT)
(FT)
AREA (SF)
STORAGE (CF)
STORAGE (CF)
0.0
389.0
2375
0
0
1.0
390.0
4240
3308
3308
2.0
391.0
6170
5205
8513
3.0
392.0
8160
7165
15678 (WQv)
4.0
393.0
10205
9183
24860
5.0
394.0
12305
11255
36115
6.0
395.0
14460
13383
49498
STORMWATER MANAGEMENT
INFILTRATION TRENCH #8
RIVER BASIN:
LUMBER
RECEIVING STREAM:
BUFFALO CREEK
STREAM INDEX:
14-2.5
STREAM CLASS:
C
HUC:
03040203
DESIGN SUMMARY
DESIGN
DRAINAGE AREA TO SCM: 4.63 ACRES
SITE IMPERVIOUS AREA TO SCM: 3.84 ACRES
OFF -SITE DESIGN IMPERVIOUS AREA TO SCM: 0.00 ACRES
TOTAL DESIGN IMPERVIOUS AREA TO SCM: 3.84 ACRES
PRE -DEVELOPED POST -DEVELOPED POST DEVELOPED
TO SCM TO SCM THROUGH SCM
DRAINAGE AREA: 4.63 AC 4.63 AC
CURVE NUMBER: 55 90.7
TIME OF CONCENTRATION: 21 MIN 5 MIN
1-YEAR STORM EVENT:
0.319 CFS
15.84 CFS
0.000 CFS
2-YEAR STORM EVENT:
1.106 CFS
20.12 CFS
0.000 CFS
10-YEAR STORM EVENT:
5.060 CFS
31.80 CFS
0.000 CFS

n
F
G
ra
d330 ,Ol < 1MI15
LS
I
r
z
W
3
W
Q
Z
Q

Pond Report s
Hydraflow Hydrographs Extension forAutoCAD® Civil 3D® 2009 byAutodesk, Inc. v6.066
Thursday, Jan 14, 2021
Pond No. 1
- BMP Pond
Pond Data
Contours - User -defined contour areas.
Average end
area method used for volume calculation. Begining Elevation
= 389.00 ft
Stage / Storage Table
Stage (ft)
Elevation (ft)
Contour area (sqft)
Incr. Storage (cuft) Total storage (cuft)
0.00
389.00
2,375
0 0
1.00
39000
4,240
3,308 3,308
2.00
391.00
6,170
5,205 8,513
3.00
392.00
8,160
7,165 15,678
4.00
393.00
10,205
9,183 24,860
5.00
394.00
12,305
11,255 36,115
6.00
395.00
14,460
13,383 49,498
Culvert / Orifice Structures
Weir Structures
[A]
[B]
[C]
[PrFRsr]
[A] IBl
[C] [D]
Rise (in)
Inactive
Inactive
Inactive
Inactive
Crest Len (ft) = 0.00 0.00
0.00 0.00
Span (in)
= 0.00
0.00
0.00
0.00
Crest El. (ft) = 0.00 000
0.00 0.00
No. Barrels
= 0
0
1
0
Weir Coeff. = 2.60 3.33
3.33 3.33
Invert El. (ft)
= 0.00
0.00
0.00
0.00
Weir Type = Broad ---
--- ---
Length (ft)
= 0.00
0.00
0.00
0.00
Multi -Stage = No No
No No
Slope (%)
= 0.00
0.00
0.00
n/a
N-Value
= .013
.013
.013
n/a
Orifice Coeff.
= 0.60
0.60
0.60
0.60
Exfil.(in/hr) = 2.170 (by Contour)
Multi -Stage
= n/a
No
Yes
No
TW Elev. (ft) = 000
Stage (ft)
6.00
5.00
4.00
3.00
2.00
1.00
Note: CulverUOrifice outflows are analyzed under inlet (ic) and outlet (oc) control Weir risers checked for orifice conditions (ic) and submergence (s)
Stage / Discharge
Elev (ft)
395.00
394.00
393.00
392.00
391.00
390.00
000 I - _ 1- 389.00
0.00 0.08 0.16 0.24 032 0.40 0.48 0.56 0.64 0.72 0.80
Total Q Discharge (cfs)

Hyd rog ra p h Summary Re Para -flow Hydrographs Extension forAutoCAD® Civil 3D® 2009 by Autodesk, Inc. v6.066

2
Hydrograph Report
Hydraflow Hydrographs Extension forAutoCAD® Civil 3D®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 =
4.630 ac
Basin Slope =
0.0 %
Tc method =
USER
Total precip. =
3.05 in
Storm duration =
24 hrs
BMP Pre -Developed
Thursday, Jan 14, 2021
Peak discharge = 0.319 cfs
Time to peak =
738 min
Hyd. volume =
3,553 cuft
Curve number =
55
Hydraulic length
= 0 ft
Time of conc. (Tc)
= 21.00 min
Distribution
= Type II
Shape factor
= 484
Q (cfs) Hyd. No. 1 -- 1 Year 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)

Hydrograph Report
Hydraflow Hydrographs Extension for AutoCADO Civil 3D0 2009 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 =
4.630 ac
Basin Slope =
0.0 %
Tc method =
USER
Total precip. =
3.05 in
Storm duration =
24 hrs
BMP Post -Developed
Hyd. No. 2 -- 1 Year
15.00
12.00
. Me
3.00
3
Thursday, Jan 14, 2021
Peak discharge = 15.84 cfs
Time to peak =
716 min
Hyd. volume =
32,950 cuft
Curve number
- 90.7
Hydraulic length
= 0 ft
Time of conc. (Tc)
= 5.00 min
Distribution
= Type II
Shape factor
= 484
Q (cfs)
18.00
15.00
12.00
M 11
. /1
Ow
0.00 1 1_ ' 0.00
0 120 240 360 480 600 720 840 960 1080 1200 1320
Hyd No. 2 Time (min)

4
Hydrograph Report
Hydraflow Hydrographs Extension forAutoCAD® Civil 3D® 2009 byAutodesk, Inc. v6.066
Thursday, Jan 14, 2021
Hyd. No. 3
Post Through Pond
Hydrograph type =
Reservoir
Peak discharge
= 0.000 cfs
Storm frequency =
1 yrs
Time to peak
T 2056 min
Time interval =
2 min
Hyd. volume
= 0 cult
Inflow hyd. No. =
2 - BMP Post -Developed
Max. Elevation
= 392.50 ft
Reservoir name =
BMP Pond
Max. Storage
20,261 cuft
Storage Indication method used
Exfiltration extracted from Outflow.
Post Through Pond
Q (cfs)
Hyd. No. 3 -- 1 Year
Q (cfs)
18.00
18.00
15.00
15.00
12.00
12.00
9.00
9.00
6.00
6.00
- 3.00
3.00
0.00
0.00
0 240 480
720 960 1200 1440 1680 1920
2160 2400 2640
2880 3120
Hyd No. 3
Hyd No. 2 Total
storage used = 20,261
Time (min)
cuff

Hyd rog ra p h Summary Re Para"flow Hydrographs Extension forAutoCAD® Civil 3D@ 2009 by Autodesk, Inc. v6.066

7
Hydrograph Report
Hydraflow Hydrographs Extension forAutoCAD® Civil 3D® 2009 by Autodesk, Inc. v6.066
Hyd. No. 1
BMP Pre -Developed
Hydrograph type =
SCS Runoff
Storm frequency =
2 yrs
Time interval =
2 min
Drainage area =
4.630 ac
Basin Slope =
0.0 %
Tc method =
USER
Total precip. =
3.69 in
Storm duration =
24 hrs
Q (cfs)
MX
W1111
BMP Pre -Developed
Hyd. No. 1 -- 2 Year
120 240 360 480 600 720 840 960
Hyd No. 1
Thursday, Jan 14, 2021
Peak discharge = 1.106 cfs
Time to peak
= 730 min
Hyd. volume
= 7,044 cuft
Curve number
= 55
Hydraulic length
= 0 ft
Time of conc. (Tc)
= 21.00 min
Distribution
= Type II
Shape factor
= 484
Q (cfs)
2.00
1.00
0.00
1080 1200 1320 1440 1560
Time (min)

8
Hydrograph Report
Hydraflow Hydrographs Extension forAutoCAD® Civil 3D® 2009 byAutodesk, Inc. v6.066
Hyd. No. 2
BMP Post -Developed
Hydrograph type = SCS Runoff
Storm frequency = 2 yrs
Time interval
= 2 min
Drainage area
= 4.630 ac
Basin Slope
= 0.0 %
Tc method
= USER
Total precip.
= 3.69 in
Storm duration
= 24 hrs
Q (cfs
21.00
18.00
15.00
12.00
We M
3.00
Thursday, Jan 14, 2021
Peak discharge = 20.12 cfs
Time to peak =
716 min
Hyd. volume =
42,427 cuft
Curve number
= 90.7
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
I '
Q (cfs)
21.00
18.00
15.00
12.00
M
M
3.00
0.00 0.00
0 120 240 360 480 600 720 840 960 1080 1200
Hyd No. 2 Time (min)

9
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 = 2 yrs
Time interval = 2 min
Inflow hyd. No. = 2 - BMP Post -Developed
Reservoir name = BMP Pond
Storage Indication method used. Exfiltration extracted from Outflow
Q (cfs)
21.00
18.00
15.00
12.00
M
WE
3.00
0.00
0 360
— Hyd No. 3
720
Post Through Pond
Hyd. No. 3 -- 2 Year
Thursday, Jan 14, 2021
Peak discharge = 0.000 cfs
Time to peak
= 594 min
Hyd. volume
= 0 cuft
Max. Elevation
= 393.17 ft
Max. Storage
= 26,744 cuft
Q (cfs)
21.00
18.00
15.00
12.00
M
.M
KRII87
0.00
1080 1440 1800 2160 2520 2880 3240 3600
Hyd No. 2 Total storage used = 26,744 cult Time (min)

10
Hyd rog ra p h Summary Re y�ra ow Hydrographs Extension for AutoCAD® Civil 3D® 2009 by Autodesk, Inc. v6.066
Hydrograph
description
BMP Pre -Developed
BMP Post -Developed
Post Through Pond
Jan 14, 2021

11
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 =
10 yrs
Time interval =
2 min
Drainage area =
4.630 ac
Basin Slope =
0.0 %
Tc method =
USER
Total precip. =
5.45 in
Storm duration =
24 hrs
5.00
4.00
3.00
W IM
1.00
M
BMP Pre -Developed
Hyd. No. 1 -- 10 Year
Thursday, Jan 14, 2021
Peak discharge = 5.060 cfs
Time to peak
= 728 min
Hyd. volume
= 20,740 cuft
Curve number
= 55
Hydraulic length
= 0 ft
Time of conc. (Tc)
= 21.00 min
Distribution
= Type II
Shape factor
= 484
Q (cfs)
6.00
5.00
4.00
3.00
alit
1.00
0.00
120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Hyd No. 1 Time (min)

ii V
Hydrograph Report
Hydraflow Hydrographs Extension forAutoCAD® Civil 3D® 2009 byAutodesk, Inc. v6.066
Hyd. No. 2
BMP Post -Developed
Hydrograph type = SCS Runoff
Storm frequency = 10 yrs
Time interval
= 2 min
Drainage area
= 4.630 ac
Basin Slope
= 0.0 %
Tc method
= USER
Total precip.
= 5.45 in
Storm duration
= 24 hrs
Q (cfs)
35.00
30.00
25.00
0411XITIM
15.00
10.00
5.00
BMP Post -Developed
Hyd. No. 2 -- 10 Year
Thursday, Jan 14, 2021
Peak discharge = 31.80 cfs
Time to peak =
716 min
Hyd. volume =
69,127 cuft
Curve number
= 90.7
Hydraulic length
= 0 ft
Time of conc. (Tc)
= 5.00 min
Distribution
= Type II
Shape factor
= 484
Q (cfs)
35.00
30.00
25.00
20.00
15.00
10.00
5.00
0.00 ' ' 0.00
0 120 240 360 480 600 720 840 960 1080 1200
Hyd No. 2 Time (min)

13
Hydrograph Report
Hydraflow Hydrographs Extension forAutoCAD® Civil 31DO 2009 byAutodesk, Inc. v6.066
Hyd. No. 3
Post Through Pond
Hydrograph type = Reservoir
Storm frequency = 10 yrs
Time interval = 2 min
Inflow hyd. No. = 2 - BMP Post -Developed
Reservoir name = BMP Pond
Storage Indication method used. Exfiltration extracted from Outflow
Q (cfs)
35.00
30.00
25.00
rM
15.00
10.00
5.00
0.00
0 360
— Hyd No. 3
720
Post Through Pond
Hyd. No. 3 -- 10 Year
Thursday, Jan 14, 2021
Peak discharge = 0.000 cfs
Time to peak
= 588 min
Hyd. volume
= 0 cuft
Max. Elevation
= 394.71 ft
Max. Storage
= 45,672 cuft
Q (cfs)
35.00
25.00
20.00
15.00
10.00
5.00
0.00
1080 1440 1800 2160 2520 2880 3240 3600 3960
Time (min)
Hyd No. 2 Total storage used = 45,672 cuft

|
`
!k
|
\
at
�#
!
2
�®
|_
�
�f
§
|)
i
a2
!
�#
\
K �
2
k
$.
!
$\�
�
i|J
■
$
k`
\t¥
§
0.8
|
°
0
0;|.
k]
�
§
7

-k� �
,��\�-iCt � CYO �t P �G