SW6210907_Design Calculations_20211105

SI-orm wafer Monogemenf Reporf
Ocfo,ber 22, 2021
Timberland Gas Station
Calloway Road
Hoke County, NC
Prepared for:
Double D Engineering, PLLC
150 S. Page Street
Southern Pines, NC 28387
910-684-8646
Prepared by:
Bowman North Carolina, Ltd.
(Formerly Triangle Site Design,
4004 Barrett Drive, Suite 101
Raleigh, NC 27609
[phone]
Firm#F-1445
j TRIANGLE
rl SITE DESIGN
a Bowman company
PLLC)
�1E%k irk',
a¢dF ,
SEAL
051571
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TABLE OF CONTENTS
OVERVIEW
FIGURES
SOILS SURVEY & SOIL INFORMATION
USGS TOPOGRAPHIC MAP
FEMA FIRM MAP
WATER SURFACE CLASSIFICATIONS
HUC
NOAA POINT PRECIPITATION FREQUENCY ESTIMATES
SHWT REPORT
WATER QUANTITY -INFILTRATION BASIN
DRAINAGE AREA MAP
DESIGN SUPPLEMENT
CN VALUES
PRE -DEVELOPMENT HYDROGRAFHS
POST -DEVELOPMENT HYDROGRAPHS
TIME VS. VOLUME (STORAGE)
TIME VS. ELEVATION (STAGE)
ELEVATION -VOLUME -FLOW SUMMARY
SCM SUMMARY
TIME OF CONCENTRATION

OVERVIEW
This report contains the storm water management overview for the proposed gas station
site on Calloway Road in Hoke County. The project site is currently un—developed. The
proposed site consists of 4.392 acres and approximately 3.72 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 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 drainage area consists of 18,267sf (0.42 ac) off —site area that will be considered
100% BUA. The drainage area also consists of 7,822sf of the future Phase 2 building and
parking area. The proposed storm water management facility (infiltration basin) outlined in
this report has been designed for post —development peak attenuation to treat the impervious
areas of the development. The Infiltration Basin is designed to capture a drainage area of
2.90 ac with an impervious area of 2.13 ac. The balance of the site is open space and
will by—pass the proposed SCM. The SCM are designed to treat a 1,0" storm event.
Impervious Area &mmary — Infiltration Basin
Parking
62,156
1.43
Sidewalk
1718
0.04
Building
3,000
0.07
Future Impervious
7 822
0.18
Off -Site
18,267
1 0.42
Total IA to Pond
92,963
1 2.13
Soils
The County Soils Survey indicates that Autryville Loamy Sand and Candor Sand soils are
present on the site.

FIGURES

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Hydrologic Soil Group —Hoke County, North Carolina
Hydrologic Soil Group
Map unit symbol
Map unit name
Rating
Acres in AOI
Percent of AOI
AuA
Autryville loamy sand, 0
to 2 percent slopes
Candor sand, 1 to 8
percent slopes
A
0.9
16.7%
CaB
A
4.7
83.3%
Totals for Area of Interest
5.6
100.0%
Description
Hydrologic soil groups are based on estimates of runoff potential. Soils are
assigned to one of four groups according to the rate of water infiltration when the
soils are not protected by vegetation, are thoroughly wet, and receive
precipitation from long -duration storms.
The soils in the United States are assigned to four groups (A, B, C, and D) and
three dual classes (A/D, B/D, and C/D). The groups are defined as follows:
Group A. Soils having a high infiltration rate (low runoff potential) when
thoroughly wet. These consist mainly of deep, well drained to excessively
drained sands or gravelly sands. These soils have a high rate of water
transmission.
Group B. Soils having a moderate infiltration rate when thoroughly wet. These
consist chiefly of moderately deep or deep, moderately well drained or well
drained soils that have moderately fine texture to moderately coarse texture.
These soils have a moderate rate of water transmission.
Group C. Soils having a slow infiltration rate when thoroughly wet. These consist
chiefly of soils having a layer that impedes the downward movement of water or
soils of moderately fine texture or fine texture. These soils have a slow rate of
water transmission.
Group D. Soils having a very slow infiltration rate (high runoff potential) when
thoroughly wet. These consist chiefly of clays that have a high shrink -swell
potential, soils that have a high water table, soils that have a claypan or clay
layer at or near the surface, and soils that are shallow over nearly impervious
material. These soils have a very slow rate of water transmission.
If a soil is assigned to a dual hydrologic group (A/D, B/D, or C/D), the first letter is
for drained areas and the second is for undrained areas. Only the soils that in
their natural condition are in group D are assigned to dual classes.
Rating Options
Aggregation Method. Dominant Condition
USDA Natural Resources Web Soil Survey 8/26/2021
Conservation Service National Cooperative Soil Survey Page 3 of 4

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8/26/2021 Precipitation Frequency Data Server
NOAA Atlas 14, Volume 2, Version 3
Location name: Raeford, North Carolina, USA'
Latitude: 35.0094°, Longitude:-79.3095'
Elevation: 379.97 ft-
'source: ESRI Maps
source: USGS
POINT PRECIPITATION FREQUENCY ESTIMATES
G M. Bonnin, D Martin, B. Lin, T. Parzybok, M-Yekta, and D. Riley
NOAA, National Weather Service, Silver Spring, Maryland
PF tabular I PF graphical I Maps & aerials
PF tabular
PDS-based point precipitation frequency estimates with 90% confidence intervals (in inches)1
puration
Average
Q 2 5 10
recurrence interval (years)
25 50 100 200 500 1000
6-min
0.665071-0
0 30 q8
R.4o0 0 569
0,54T-.0.0fi3
[0.604 0 732)
(d 6.515
815)
[0.7019-0 874
0.7� -0932
() 803 i} 98
0_sp61�b i
0.8951.11
10�t1in
0.636 0.769
0-15 $09i❑
0.8776706
0-967 617
(1 0711830)
(1.15 1739
1.213 49) 1 [1 2741356]
1 345267
1 40-1974)
6.872
1.04
1.22
1.35
1.50
1.61
1.71 1.80
1.91
1.99
15 mtn
0-794.0-962
. 0.945-1-14
1-11-1.34
1-22-148
1 36-1..65
1.45-1 76
(153-187) 1 (1 61.1.97)
(169-210
1 75-219
3.04
3.22
1.20
1.43
1.73
1.95
2.22
2.42
2.62 2.80
30{t1m
(1-09-1.32)
1 (1.31-1.58)
1 (1.58-1.91)
1 (1 77-2 15)
2.01-2-44
2.18.2.65)
(2-35-2-87)2.50.3-07)
11 (2 69.3.34)
(2 84.3 54)
1.49
1.80
2.22
2.54
2.96
3.28
3.60 3.93
4.37
4.71
604tun
.1,36-1.64
1,64-1.96)
1 (2.31.2.79
2G7-3-25
2.96-3.60
3-23.3.95 3-61-430
3.86-479
414-517
2-hr
1.58 1 94
1.91 215
2 442595
2 6-3 41
3-25 4.02)
3.63-4.51
(4.005000 4.37 5650)
1(4.6758.18
5-25-6.73
3-hr
(1.62 2406
Z022350
2 55-3.14
(2 96 3866)
(3.5 -4.37
3.96 4.94)
(4.4195.54 (4-87-616 .
5.51'3 ,05
(B 000177
6-hr
1.99 244
22 95
3-04-.172
(3.54 4234)
(4.22509) 11
(4. 63589)
1 (532-6.62 (5.897239
6: $-8-4&
7 0938
6.4511
12-hr
[2-34 2988
2-84.3.49
3- 94-42.
4-20-518
5.03 fi424]
5 71-7
(6-41-8.04) 1 (7 4-905)
(5- 5--10.5
8.96-111 7
24-h r
(2: 3 3530
3.2 4900)
4-325705
5.02-5599
5,99-`-7 04
5 763 .96
7 548.92) (8.36.9.9❑
(946.11 3)
1(10.3. 2 4
11.8
12.9
3.54
4.28
5.377
6.23
7.42
F 8.38
9.36 10.4
2�tay
(3-30 3-82}1
(3-98.4.61) 1[4
99-5.78}
(5 78-6 71
6.86-7.99
7-71-9.01)
11 (8-59-10.1) (9,48.11.2)
(10 7-12 7)
11 ( 11 7-1-39)
3.76
4.53
5.65
6.55
7.77
8.75
9.76 10.8
12.2
3�lay
3.51-4.03
4.23-4.8
5.27-5.06
6.09-7.01
?
7.20.8 3�
8-069 37
8.99-10.5 9-91-11.fi
11.2-13.1
ry13.4
1_.1-14 4
4�iay
3 2 4825
4.48-5.11
5 55-a 34y
6.4087631
s 18 66
8.46 9373
9:39-0.8 10 3-12-0
11 6-13.6
(12 6--14 8
7�ay
[A.3 4193}
(5.1G5189)
(7 23-8 29
8 48 9 74)
(9 46- 0.9
10.5- 2.1
(11 5-13:3)
(1219-15.0
1
[140-16.4)
10�ay
4-98 5862y
(5 336.6)
[7 I6 H 08)
8.181 941
9-39-10.0
10 4- 1.8}
t11 4-13.0
1214-14 2
13.74-15.8
14 8- U 1
F 20.1
7.11
8.41
10.00
11.2
12.9
14.2
15.5
16.9
20�1ay
6.71-7-53
7.95-8.92
9-43-10-6)
1 (10 6-11 9
12 1-13 7) 1
14.5-16.5
15.7-17 9
(17 3-19.9)
(18 6-21 4)
3.5
2
30�ay
8-5 9334
9.8 -141-0
1115-129
1218--14-3
(1414-16.2
15,7--17.6
16.9- 91)
181- 0.5
198-225
210- 4,0
45 day
11.2
(10-6-11.8)
13.1
(12 4-13.8)
15.1
(14 3-15.9)
16.6
(15-7-17 5
18.5
17.5-19.5)
20.0
(18-8-21-1)
21.4
( 20 2-22 6)
22.8
1 (21.5-24-1)23.1-26.1
28.2
(24.4-27 7)
29.7
13.4
15.7
17.8
19.5
21.6
23.2
24.7
26.2
60{lay
12.7-14 1
14.9-16.5
16 9-18 7)
18.5-20 5 )
20.5-22 7
21 9-24 4
(23 q 28.1
24 7-27.7
26.5-29.8
27.8-31 4
t Precipitation frequency (PF) estimates in this table are based on frequency analysis of partial duration series (PDS)-
Numbers in parenthesis are PF estimates at lower and upper bounds of the 90% confidence interval The probability that precipitation frequency estimates (for
a given duration and average recurrence interval) will be greater than the upper bound (or less than the lower bound) is 5% Estimates at upper bounds are
not checked against probable maximum precipitation (PMP) estimates and may be higher than currently valid PMP values
Please refer to NOAA Atlas 14 document for more information.
Back to Top
PF graphical
https://hdsc.nws.noaa.gov/hdsc/pfds/pfds_printpage.html?Iat=35.0094&Ion=-79.3095&data=depth&units=english&series=pds 1/4

Scott Cole, A'CLSS
312 Copples Road Ext
Asheboro, NC 27205
[phone]
Double D Engineering, PLLC
Attn: Mr. Lee Humphrey
150 S. Page Street
Southern Pines, NC 28387
August 10, 2021
Re: Seasonal High -Water Table Identification and Soil Infiltration Rates: Proposed Gas Station
(Timberland Ranch). Hoke County, NC (PIN 594060001097)
Soil conditions and infiltration rates were evaluated and measured on the above -referenced property
within the proposed storm water BMP device. Work was conducted in accordance with Parts A-2 and C-
1 of the North Carolina De )arlmel7l of Environmental Quality Stoi-iniv ter Design Manual. Soil samples
were evaluated with a hand auger.
SEASONAL HIGH WATER TABLE IDENTIFICATION
Seasonal High Water Table depth is determined by field evaluation for soil wetness conditions which are
indicated by the presence of redoximorphic (redox) features with a chroma of 2 or less (in Munsell color
notation) in mottles or the horizon matrix. Colors of chroma 2 or less due to relic minerals from parent
material (underlying rock), anaerobic activity created by placement of fill material, or soil textural class
transitions (perched water) are not considered as indicators for seasonal high water. Upon determination
of SHWT depth, an additional 6" will be deducted from the observed depth to account for capillary fringe
water movement above the SHWT. Stormwater infiltration trenches are designed to ensure the lowest
point is at least two feet above the Seasonal High Water Table (SHWT).
The SHWT for this P ra'ect was identified within the pro used BMP device at elevation 366'
Ca_ntbroaimateIy_15' belowground surface.).
SATURATED HYDRAULIC CONDUCTIVITY KSa,
Soils within the proposed stormwater BMP device typical of those within the Candor Sand series. Candor
Sands are very deep and excessively drained soils with moderately high rates of permeability. Infiltration
rates were measured to determine the suitability for installation of a stormwater infiltration BMP.
Infiltration rates were measured using a Johnson Constant Head Perneameter. Measurements were
recorded at varying intervals until equilibrium was reached.
A summary of observations within the proposed Stormwater BMP Device is shown in the table below.
BMP Device Site #1
Boring 9
SHWT
Dlunsell Color
Ksat #t
Ksat 42
Ksat 43
Ksat #4
(feet below
Notation
round surface
1
15'
51' 8/1
0-7'
7-9.5'
9.5-13'
13-15
SHWT
2.5Y 7/1
LS/SL
Perched water
SL/SCL
Crs LS
elevation: 366'
22" / hour
Not Measured
3" / hour
15" / hour

Scott Cole, NCLSS
312 Copples Road Ext
Asheboro, NC 27205
[phone]
CONCLUSION
Field evaluation of hydraulic conductivity provides estimations of soil infiltration rates; however,
methods used to measure these rates can influence the results. Side walls of the bore hole are "smeared"
by the soil auger as the hole is prepared and loose soil in the bottom of the hole is placed in suspension
when water is applied; both of these factors negatively influence water infiltration rates. To help
overcome these issues, after excavation of each infiltration trench, it is recommended the trench bottom
and sidewalls be raked and dusted with pulverized limestone. These are practices that have been in place
within the on -site wastewater industry to help loosen the soil and aid in restoration of soil structure.
I am pleased to be of service in this matter and can be contacted at your convenience should you have any
questions concerning information within this report.
Thank you.
Scxol
North Carolina Licensed Soil Scientist
9,P+ KL 1
Q a

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i STORMwAiEPy
.� . ENT --
Solt C
Test Location (Elevation 381') CA=CZVAY R(L
SHWT: 15' bgs t
SHWT Elevation: 366'
Ksat 0-7' LSISL: 22" 1 hour
Ksat 7-9.5' SCLlSC: perched water NOT Measured r
Ksat 9.5-13' SUSCL: 3" / hour ~�
Ksat 13-15' LS Coarse: 15" 1 hour _
� r
T� 2AOR11ir
�' I ems+ � ��1 •-��
1 inch = 60 feet -�-

WATER QUANTITY -INFILTRATION BASIN

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SUPPLEMENT-EZ COVER PAGE
FORMS LOADED
f PROJECT INFORMATION-
4f 1 Project Name
Timberland Gas Station
2 Project Area (ac) _
4.392
3 Coastal Wetland Area (ac)
4 ISurface Water Area ac
_ -
5 Is this project High or Low Density?
High
6
Does this project use an off -site SCM?
No
COMPLIANCE WITH 02H .1003(4) _ {
_7 l Width of vegetated setbacks provided (feet) N/A
8 Will the vegetated setback remain vegetated? N/A
9 If BUA is proposed in the setback, does it meet NCAC 02H.1003 4 c-d ? No
10 Is streambank stabilization proposed on this project? No
NUMBER AND TYPE OF SCMs:
11
Infiltration System
1
12
Bioretention Cell
0
13
Wet Pond
0
14
Stormwater Wetland
0
15
Permeable Pavement
0
16
Sand Filter
0
17
Rainwater Harvesting RWH
0
18
Green Roof
0
19
Level Spreader -Filter Strip LS-FS
0
20
Disconnected Impervious Surface DIS
0
21
Treatment Swale
0
22
Dry Pond
0
23
StormFilter
0
24
Silva Cell
0
25
Ba alter
0
26
_
Filterra
0
FORMS LOADED
DESIGNER CERTIFICATION
27
Name and Title:
Organization—
Carlo Pardo, PE
28
Bowman North Carolina, Ltd.
29
_
Street address:
4004 Barrett Drive, Suite 101
30
City, State, Zip:
Raleigh, NC 27609
31
Phone numbers :
919-553-6570
32
Email:
[e-mail]
Certification Statement
I certify, under penalty of law that this Supplement-EZ form and all supporting information were prepared under my direction or supervision; that the
information provided in the form is, to the best of my knowledge and belief, true, accurate, and complete; and that the engineering plans,
specifications, operation and maintenance agreements and other supporting information are consistent with the information provided here.
AIRQ�
S51p0;q�'���
SEAL
051571
C. .........
Signature of Designer
b ';�a a
Date

DRAINAGE AREAS
1
Is this a high density project?
Yes
2
o, number of drainage areas/SCMs
If sDoes
1
3
this project have low density areas?
No
4
If so, number of low density drainage areas
0
5
Is all/part of this project subject to previous rule
versions?
No
FORMS LOADED
DRAINAGE AREA INFORMATION
Entfire Site
1
4
Type of SCM �~
-
Infiltration Basin
5
Total drainage area (sq ft
191320 sf
126116 sf
6
Onsite drainage area (sq ft
191320 sf
107849 sf
7
Offsite drainage area (sq ft
18267 sf
18267 sf
8
Total BUA in project (sq fl
101189 sf
92963 sf
9
New BUA on subdivided lots (subject to permitting)
(sq ft
10
New BUA not on subdivided lots (subject to
permitting) (sf)
11
Offsite BUA (sq ft
18267 sf
18267 sf
12
Breakdown of new BUA not on subdivided lots:
Parkin (sq ft
Sidewalk (sq ft
1718 sf
1718 sf
Roof (sq ft
3000 sf
3000 sf
Roadway s ft
70382 sf
62156 sf
Future (sq ft
Other, please specify in the comment box
below sq ft
7822 sf
7822 sf
13
New infiltrating permeable pavement on
subdivided lots (sq ft
14
New infiltrating permeable pavement not on
subdivided lots (sq ft
15permitting)_
Existing BUA that will remain (not subject to
s ft
16
Existing BUA that is already permitted (sq ft
17
xis inq BUA that will be removed (sq ft
18
Percent BUA
39.25%'On Site
74%
19
Design storm inches
1.0 in
20
Design volume of SCM (cu ft)
7498 cf
21 1
Calculation method for design volume
I Simple Method
ITIONAL INFORMATION
Please use this space to provide any additional information about the
22 drainage area(s):
Offsite Drainage area includes a portion of Calloway Road and the future Lot
68 in the Timberland Ranch development = 18267 sf. There is future
building/sidewalk/pavement included in the impervious calculations:
5000sf/620sf/2202sf, respectively = 7822 sf. There is 8226sf of bypass from

INFILTRATION SYSTEM
1 Drama e area number _ � 1
2 Minimum required treatment volume (cu ft) 7498 cf
3
Is the SCM sized to treat the SW from all surfaces at build -out?
Yes
4
Is the SCM located away from contaminated soils?
Yes
5
What are the side slopes of the SCM (H:V or enter "Vertical' for
trenches)?
3:1
6
Does the SCM have retaining walls, gabion walls or other engineered
side slopes?
No
7
Are the inlets, outlets, and receiving stream protected from erosion
(10- ear storm)?
Yes
8
Is there an overflow or bypass for inflow volume in excess of the
design volume?
Yes
9
What is the method for dewatering the SCM for maintenance?
Pump (preferred)
10
If applicable, will the SCM be cleaned out after construction?
Yes
11
Does the maintenance access comply with General MDC (8)?
Yes
12
Does the drainage easement comply with General MDC (9)?
Yes
13
If the SCM is on a single family lot, does (will?) the plat comply with
General MDC (10)?
NIA
14
Is there an O&M Agreement that complies with General MDC (11)?
Yes
15
Is there an O&M Plan that complies with General MDC (12)?
Yes
16
Does the SCM follow the device specific MDC?
Yes
17
Was the SCM designed by an NC licensed rofessional?
Yes
TIM cvc-mM iM FROM fixk{ . Si
18
Proposed sloe of the subgrade surface (°l,)
0%
19
Are terraces or bafflesprovided?
No
20
]Type of pretreatment:
Forebay
21
Was the soil investigated in the footprint and at the elevation of the
infiltrations stem?
Yes
22
SHWT elevation (fmsl)
366.00 _
23
Depth to SHWT per soils report (in)
180.00
24
Ground elevation at boring in soils re ort (fmsl)
381.00
25
Is a detailed hydrogeologic study attached if the separation is
between 1 and 2 feet?
Yes
26
Soil infiltration rate (in/hr)
11.00
27
Factor of safety (FS) (2 is recommended):
2.00
Elevaflbns
29
Bottom elevation (fmsl)
378 ft
30
Storage elevation (fmsl)
380. ft
31
Bypass elevation (fmsl)
380.7 ft
For Basins Only
32
Bottom surface area (ft 2)4975 ft
33
Stora a elevation surface area ft2 7075. ft
34
Length (ft)
35
jWidth (ft)
36
jPerforated pipe diameter, if applicable (inches)
37
Number of laterals
38
Total len th of perforated piping
39
Stone type, if applicable
40
Stone porosity (%)
41
Is stone free of fines?
42
Is the stone wrapped in 2eotextile fabric?
43
Has at least one inspection port been provided?
Volumes/Drawdown
44 IDesion volume of SCM (cu ft) 7498 of
45 ITime to draw down (hours) 3 hrs
ADDITIONAL INFORMATION
46 Please use this space to provide any additional information about the
infiltration system(s):
Infiltration 3 9:50 AM 1012212021

Triangle Site Design, PLLC
Timberland Gas Station, Hoke County, NC
Curve Number Calculation (CN)
Pre -Developed Conditions
Drainage Area (acres 4.81
Existing Soil Groups_
Sod Grouo Map Symbol Soil Description Acres Percent of DA
A AuA Autryville Loamy Sand 4.41 92%
A CaB Candor Sand 0.40 8%
_Existing Land Uses
Land Use Description Existing Soil Group Acres Curve # Weighted CN
Open Space - Good Stand A 4.72 59 57.9
Impervious -Roadway A 0.09 98 1.8
Cumulative Curve # = 59.7

Triangle Site Design, PLLC
Timberland Gas Station, Hoke County, NC
Curve Number Calculation (CN)
Post -Developed Conditions to Infiltration Basin
Drainage Area (acres]_.' 2.90
Existing Soil Groups.
Soil Grouo Map Symbol Soil Description Acres Percent of DA
A AuA Autryville Loamy Sand 2.50 86%
A CaB Candor Sand 0.40 14%
Proposed Land Uses:
Land Use Description Existinq_Soil Group Acres Curve # Weighted CN
Open Space - Good Stand A 0.77 59 15.7
Impervious Area A 2.13 98 72.0
Cumulative Curve # = 87.6

Triangle Site Design, PLLC
Timberland Gas Station, Hoke County, NC
Curve Number Calculation (CN)
Post -Developed Bypass Conditions to Infiltration Basin
Drainage Area {acres : 1.91
Existing Soil Groups_
Soil Group Map Symbol Soil Description Acres Percent of DA
A AuA Autryville Loamy Sand 1.91 100%
A CaB Candor Sand 0.00 0%
Proposed Land Uses'
Land Use Description Existing Soil Group Acres Curve # Weighted CN
Open Space - Good Stand A 1.72 59 53.1
Impervious Area A 0.19 98 9.7
Cumulative Curve # = 62.9

Infiltration Basin Design
Site Information
Sub Area Location:
Drainage To Infiltration Basin
Drainage Area (DA) =
2.90 Acres 126116 sf
Impervious Area (IA) =
2.13 Acres 92963 sf
Percent Impervious (1) =
73-7 %
Required Water Quality Volume
Design Storm = 1 inch
Determine Rv Value = 0.05 + .009 (1) = 0.71 in/in
Water Quality Volume = 0.172 ac-ft
Water Quality Volume = 7,496 cf
Water Quality Volume = 0.713 inches of runoff
NOAA 1-year. 24-hour event = 3.05 inches
Minimum Surface Area
SA =
(12-FS"DV)/(K"T)
Factor of Safety (FS) =
2
Design Volume (DV) =
7497.7 cf
Hydraulic Conductivity of Soil =
11.00 in/hr
Max Dewatering Time =
72 hours
SA =
227.2 sf
Time to Draw Down
Dewatering Time =
(12-FS"DV)/(K"SA)
Factor of Safety (FS) =
2
Design Volume (DV) =
7497.7 cf
Hydraulic Conductivity of Soil =
11.00 in/hr
Surface Area (SA) Provided =
4975 sf
T =
3.3 hrs

0
00
r
m
l
\\ \ I I
I i I

'STAGE/STORAGE TABLE
INFILTRATION BASIN
STAGE
ELEVATION
CONTOUR
INCREMENTAL
TOTAL
(FT)
LFT)
AREA (SF)
STORAGE (CF)
STORAGE (CF)
0.0
378.0
4975
0
0
1.0
379.0
5995
5485
5485
2.0
380.0
7075
6535
12020
3.0
381.0
8205
7640
19660
4.0
382.0
9400
8803
28463
ORMWATER MANAGEMENT DESIGN
INFILTRATION BASIN
RIVER BASIN: CAPE FEAR
RECEIVING STREAM: MILL CREEK
STREAM INDEX: 18-31-11
STREAM CLASS: C
HUC: 03030004
POND DESIGN SUMMARY
DRAINAGE AREA TO POND: 2.90 ACRES
SITE IMPERVIOUS AREA TO POND: 1.71 ACRES
OFF -SITE DESIGN IMPERVIOUS AREA TO POND: 0.42 ACRES
TOTAL DESIGN IMPERVIOUS AREA TO POND: 2.13 ACRES
PRE -DEVELOPED POST -DEVELOPED POST DEVELOPED POST DEVELOPED POST DEVELOPED
THROUGH POND BYPASS COMBINED
DRAINAGE AREA: 4.81 AC 2.90 AC 1.91 AC
CURVE NUMBER: 59.7 87.6 62.9
INFILTRATION RATE: 11.0 IN/HR
1.0" STORM EVENT:
0.515 CFS
0.000 CFS
1-YEAR STORM EVENT:
0.957 CFS
8.850 CFS
0.000 CFS
0.908 CFS
0.908 CFS
2-YEAR STORM EVENT:
2.226 CFS
11.52 CFS
0.000 CFS
1.794 CFS
1.794 CFS
10-YEAR STORM EVENT:
7.302 CFS
18.88 CFS
0.000 CFS
4.805 CFS
4.805 CFS
100-YEAR STORM EVENT:
17.60 CFS
30.49 CFS
18.87 CFS
10.59 CFS
29.46 CFS

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Hydrograph Report
Hydraflow Hydrographs Extension for AutoCADO Civil 3D® 2009 by Autodesk, Inc. v6.066
Hyd. No. 3
Post Through SCM
Hydrograph type
= Reservoir
Peak discharge
Storm frequency
= 100 yrs
Time to peak
Time interval
= 2 min
Hyd. volume
Inflow hyd. No.
= 2 - SCM Post -Developed
Reservoir name
Max. Elevation
= 381.33 ft
Max. Storage
0
Friday, Oct 22, 2021
= 18.87 cfs
= 12.00 hrs
= 13,670 cuft
= BMP Pond
= 22,439 cuft
Storage Indication method used. Exfiltration extracted from Outflow.
Hydrograph Discharge Table (Printed values - 1 00% of Op)
Time Inflow Elevation Clv A Clv B Clv C PfRsr Wr A Wr B Wr C Wr D Exfil Outflow
(hrs) cfs ft cfs cfs cfs cfs cfs cfs cfs cfs cfs cfs
11.931
30.49 <<
380.97 ----- ----- ----- -----
5.614 -----
----- ----- 2.081
5.614
11.97
29.29
381.22 ---- ----- _-_-- -----
14.55 --
----- ----- 2.155
14.55
12.00
22.87
381.32 << __-- - - ----- -----
18.87 -----
----- ----- 2.185
18.87 <<
12.03
14.33
381.29 ----- - - --- -----
17.70 -----
----- ---- 2.178
17.70
12.07
7.866
381.20 ----- ----- ----- -----
13.71 -----
----- ----- 2.149
13.71
12.10
4.875
381.10 ----- - - --_-- -----
9.728 -----
----- ----- 2.118
9.728
12.13
3.998
381.01 ----- - - ----- -----
6.906--------
----- 2.094
6.906
12.17
3.826
380.95 ----- - - ----- -----
5.001 -----
----- ----- 2.075
5.001
12.20
3.664
380.91 ----- ----- --- -----
3.761 -----
---- ----- 2.063
3.761
12.23
3.502
380.88 ----- ----- ----- -----
3.035 -----
----- ----- 2.055
3.035
12.27
3.339
380.86 ----- ----- ----- --
2.534 -----
----- ----- 2.048
2.534
12.30
3.176
380.84 ----- - - ----- -----
2.136 -----
- -- ----- 2.043
2.136
12.33
3.013
380.83 ----- -_-_- ___-- ___-
1.810 -----
_ - _---- 2.039
1.810
12.37
2.849
380.81 ----- ---- ---- --
1.534 -----
-__-- ----- 2.036
1.534
12.40
2.686
380.80 ---- -- - -----
1.293 -----
----- ----- 2.032
1.293
12.43
2.522
380.79 ----- ----- ----- -----
1.141 -----
----- --- 2.030
1.141
12.47
2.358
380.78 ----- _ - ----- -----
1.012 -----
----- ----- 2.027
1.012
12.50
2.193
380.77 ----- ---- ----- -----
0.878 -----
----- ----- 2.023
0.878
12.53
2.041
380.76 ----- ---- ---- ----
0.739 -----
----- ----- 2.020
0.740
12.57
1.928
380.75 ----- ----- ----- -----
0.603 -----
----- ----- 2.017
0.603
12.60
1.857
380.74 ----- ----- ---- -----
0.475 -----
----- ---- 2.014
0.475
12.63
1.811
380.73 ----- ----- ----- -----
0.359 ----
----- ----- 2.011
0.359
12.67
1.774
380.72 ----- ----- ----- -----
0.257 -----
----- ----- 2.009
0.257
End

10/22/21, 9:44 AM
NORTH
AMERICAN
GREEN'
SPILLWAY ANALYSIS
> > > Grass Spillway
Name
Grass Spillway
Discharge
18.87
Peak Flow Period
1
Channel Slope
0.3333
Channel Bottom Width
15
Low Flow Liner
Retardence Class
C 6-12 in
Vegetation Type
Mix (Sod and Bunch)
Vegetation Density
Very Good 80-95%
Soil Type
Sandy Loam (GM)
C350 - Class C - Mix
(Sod & Bunch) - Very Good 80-95%
ECMDS 7.0
North American Green
5401 St. Wend el -Cynthia na Rd.
Poseyville, Indiana 47633
Tel. [phone]
> Fax [phone]
www.nagreen.com
ECMDS v7.0
Normal
Permissible
Calculated
Safety
Staple
Phase
Reach
Discharge
Velocity
Mannings N
Remarks
Depth
Shear Stress
Shear Stress
I Factor
Pattern
C350
Straight
18.87 cfs
8.66 ft/s
0.15 ft
0.027
3.2 Ibs/ft2
3.02 Ibs/ft2
1.06
STABLE E
Unvegetated
Underlying
Straight
18.87 cfs
8.66 ft/s
0.15 ft
0.027
3.03 Ibs/ft2
2.96 Ibs/ft2
1.02
STABLE E
Substrate
C350 Reinforced
Straight
18.87 cfs
8.17 ft/s
0.15 ft
0.03
12 Ibs/ft2
3.19 Ibs/ft2
3.76
STABLE E
Vegetation
Underlying
Straight
18.87 cfs
8.17 ft/s
0.15 ft
0.03
3.2 Ibs/ft2
3.13 Ibs/ft2
1.02
STABLE E
Substrate
https://ecmds.com/projecUl 1/1

Pond Report
M
Hydraflow Hydrographs Extension for AutoCADO Civil 3D® 2009 by Autodesk, Inc. v6.066
Friday, Oct 22, 2021
Pond No. 1 - BMP Pond
Pond Data
Contours - User -defined contour areas. Average end area method used for volume calculation. Begining Elevation = 378.00 ft
Stage / Storage Table
Stage (ft) Elevation (ft)
Contour area (sgft)
Incr. Storage (cult)
Total storage (cuft)
0.00 378.00
4,975
0
0
1.00 379.00
5,995
5,485
5,485
2.00 380.00
7,075
6,535
12,020
3.00 381.00
8,205
7,640
19,660
4.00 382.00
9,400
8,803
28,463
Culvert / Orifice Structures
Weir Structures
[A]
[B]
[C]
[PrPRSr]
[A]
[B]
[C]
[D]
Rise (in)
Inactive
Inactive
Inactive
Inactive
Crest Len (ft)
= 15.00
0.00
0.00
000
Span (in)
= 0.00
0.00
0.00
0.00
Crest El. (ft)
= 380.70
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)
= 11.000 (by Contour)
Multistage
= n/a
No
Yes
No
TW Elev. (ft)
= 0.00
Stage (ft)
4.00
3.00
2.00
M6
0.00
0.00 6.00
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
12.00 18.00 24.00 30.00 36.00 42.00 48.00
Elev (ft)
382.00
381.00
380.00
379.00
378.00
54.00 60.00 66.00
Discharge (cfs)

Hydrograph Summary Re p aflow Hydrographs Extension for AutoCADO 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
(cult)
Inflow
hyd(s)
Maximum
elevation
(ft)
Total
strge used
(cuft)
Hydrograph
description
1
SCS Runoff
0.957
2
730
6,074
-- -
----
SCM Pre -Developed
2
SCS Runoff
8.850
2
716
18,065
—
---
------
SCM Post -Developed
3
Reservoir
0.000
2
712
0
2
379.25
7,103
Post Through SCM
4
SCS Runoff
0.908
2
722
3,218
---
------
-
SCM Post -Developed Bypass
6
SCS Runoff
0.515
2
146
2,378
---
----
1.0 Post -Developed to SCM
7
Reservoir
0.000
2
152
0
6
378.11
607
1.0inPost Through SCM
Infiltration.gpw
Return Period: 1 Year
Friday, Oct 22, 2021

P:
Hydrograph Report
Hydraflow Hydrographs Extension for AutoCAD® Civil 3DO 2009 by Autodesk, Inc. v6.066
Hyd. No. 1
SCM Pre -Developed
Hydrograph type =
SCS Runoff
Storm frequency =
1 yrs
Time interval =
2 min
Drainage area -
4.810 ac
Basin Slope =
0.0 %
Tc method =
USER
Total precip. =
3.05 in
Storm duration =
24 hrs
SCM Pre -Developed
Friday, Oct 22, 2021
Peak discharge = 0.957 cfs
Time to peak
= 730 min
Hyd. volume
= 6,074 cuft
Curve number
= 59.7
Hydraulic length
= 0 ft
Time of conc. (Tc)
= 20.80 min
Distribution
= Type II
Shape factor
= 484
Q (cfs) Hyd. No. 1 -- 1 Year Q (cfs)
1.00 ;- 1.00
0.90 0.90
0.80 0.80
0.70 0.70
0.60 0.60
0.50 0.50
0.40 0.40
0.30 0.30
0.20 0.20
0.10 0.10
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 for AutoCADO Civil 3D® 2009 by Autodesk, Inc. v6.066
Hyd. No. 2
SCM Post -Developed
Hydrograph type =
SCS Runoff
Storm frequency =
1 yrs
Time interval =
2 min
Drainage area =
2.900 ac
Basin Slope =
0.0 %
Tc method =
USER
Total precip. =
3.05 in
Storm duration =
24 hrs
Q (cfs)
10.00
M
. ��
H YX
rm
SCM Post -Developed
Hyd. No. 2 -- 1 Year
120 240 360 480 600 720
Hyd No. 2
Friday, Oct 22, 2021
Peak discharge = 8.850 cfs
Time to peak =
716 min
Hyd. volume =
18,065 cuft
Curve number
= 87.6
Hydraulic length
= 0 ft
Time of conc. (Tc)
= 5.00 min
Distribution
= Type II
Shape factor
= 484
Q (cfs)
10.00
we]
4.00
2.00
0.00
840 960 1080 1200 1320 1440
Time (min)

4
Hydrograph Report
Hydraflow Hydrographs Extension for AutoCAD® Civil 3D0 2009 by Autodesk, Inc. v6.066
Hyd. No. 3
Post Through SCM
Hydrograph type = Reservoir
Storm frequency = 1 yrs
Time interval = 2 min
Inflow hyd. No. = 2 - SCM Post -Developed
Reservoir name = BMP Pond
Storage Indication method used. Exfiltration extracted from Outflow.
Q (cfs)
10.00
More
4.00
2.00
0.00
0 120 240
Hyd No. 3
Post Through SCM
Hyd. No. 3 -- 1 Year
360 480 600 720
Hyd No. 2
Peak discharge
Time to peak
Hyd. volume
Max. Elevation
Max. Storage
Friday, Oct 22, 2021
= 0.000 cfs
= 712 min
= 0 tuft
= 379.25 ft
= 7,103 cuft
Q (cfs)
10.00
ee
. �e
4.00
2.00
0.00
840 960 1080 1200 1320 1440 1560
Time (min)
® Total storage used = 7,103 cult

Hydrograph Report
Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2009 by Autodesk, Inc. v6.066
Hyd. No. 4
SCM Post -Developed
Bypass
Hydrograph type
= SCS Runoff
Storm frequency
= 1 yrs
Time interval
= 2 min
Drainage area
= 1.910 ac
Basin Slope
= 0.0 %
Tc method
= USER
Total precip.
= 3.05 in
Storm duration
= 24 hrs
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
0.2'0 0.20
0.10 0.10
0.00 — - - 0.00
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Hyd No. 4 Time (min)
0
Friday, Oct 22, 2021
Peak discharge = 0.908 cfs
Time to peak
= 722 min
Hyd. volume
- 3,218 cuft
Curve number
= 62.9
Hydraulic length
= 0 ft
Time of conc. (Tc)
= 10.00 min
Distribution
= Type II
Shape factor
= 484
SCM Post -Developed Bypass
Hyd. No. 4 -- 1 Year

7
Hydrograph Report
Hydraflow Hydrographs Extension for AutoCADO Civil 3DO 2009 by Autodesk, Inc. v6.066
Hyd. No. 6
1.0 Post -Developed to SCM
Hydrograph type
= SCS Runoff
Storm frequency
= 1 yrs
Time interval
= 2 min
Drainage area
= 2.900 ac
Basin Slope
= 0.0 %
Tc method
= USER
Total precip.
= 1.00 in
Storm duration
= 6.00 hrs
Q (cfs)
1.00
0.90
0.80
0.70
0.60
0.50
0.40
0.30
0.20
0.10
0 00
Friday, Oct 22, 2021
Peak discharge = 0.515 cfs
Time to peak
= 146 min
Hyd. volume
= 2,378 cuft
Curve number
= 87.6
Hydraulic length
= 0 ft
Time of conc. (Tc)
= 5.00 min
Distribution
= SCS 6-Hr
Shape factor
= 484
1.0 Post -Developed to SCM
Hyd. No. 6 -- 1 Year
Q (cfs)
1.00
0.90
0.80
0.70
0.60
0.50
0.40
0.30
0.20
0.10
000
0 60 120 180 240 300 360 420
Time (min)
Hyd No. 6

Hydrograph Report
0
Hydraflow Hydrographs Extension for AutoCADO Civil 31DO 2009 by Autodesk, Inc. v6.066 Friday, Oct 22, 2021
Hyd. No. 7
1.0inPost Through SCM
Hydrograph type = Reservoir Peak discharge = 0.000 cfs
Storm frequency = 1 yrs Time to peak = 152 min
Time interval = 2 min Hyd. volume = 0 cuft
Inflow hyd. No. = 6 - 1.0 Post -Developed to SCM Max. Elevation = 378.11 ft
Reservoir name - BMP Pond Max. Storage = 607 cuft
Storage Indication method used. Exfiltration extracted from Outflow.
Q (cfs)
1.00
0.90
0.80
0.70
0.60
0.50
0.40
0.30
0.20
0.10
0.00
0
Q (cfs)
1.00
0.90
0.80
0.70
0.60
0.50
0.40
0.30
0.20
0.10
0.00
60 120 180 240 300 360 420 480 540 600 660
Hyd No. 7 Hyd No. 6 ® Total storage used = 607 cult Time (min)
1.0inPost Through SCM
Hyd. No. 7 -- 1 Year

10
Hydrograph Summary Re p Nydraflow Hydrographs Extension for AutoCADO Civil 3DO 2009 by Autodesk, Inc. v6.066
Hyd.
No.
Hydrograph
type
(origin)
Peak
flow
(cfs)
Time
interval
(min)
Time to
peak
(min)
Hyd.
volume
(cuft)
Inflow Maximum
hyd(s) elevation
(ft)
Total
strge used
(cuft)
Hydrograph
description
1
SCS Runoff
2.226
2
730
10,701
- -
------
SCM Pre -Developed
2
SCS Runoff
11.52
2
716
23,754
--
- -
- -
SCM Post -Developed
3
Reservoir
0.000
2
862
0
2
379.64
9,664
Post Through SCM
4
SCS Runoff
1.794
2
722
5,359
------
--
SCM Post -Developed Bypass
6
SCS Runoff
0.000
2
n/a
0
----
----
----
1.0 Post -Developed to SCM
7
Reservoir
0.000
2
n/a
0
6
378.00
0.000
1.0inPost Through SCM
Infiltration.gpw
Return Period: 2 Year
Friday, Oct 22, 2021

11
Hydrograph Report
Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2009 by Autodesk, Inc. v6.066
Hyd. No. 1
SCM Pre -Developed
Hydrograph type =
SCS Runoff
Storm frequency =
2 yrs
Time interval =
2 min
Drainage area =
4.810 ac
Basin Slope =
0.0 %
Tc method =
USER
Total precip. =
3.69 in
Storm duration =
24 hrs
Q (cfs)
3.00
2.00
1.00
SCM Pre -Developed
Hyd. No. 1 -- 2 Year
120 240 360 480 600 720 840 960
Hyd No. 1
Friday, Oct 22, 2021
Peak discharge = 2.226 cfs
Time to peak =
730 min
Hyd. volume =
10,701 cuft
Curve number =
59.7
Hydraulic length
= 0 ft
Time of conc. (Tc) =
20.80 min
Distribution
= Type II
Shape factor
= 484
Q (cfs)
3.00
2.00
1.00
0.00
1080 1200 1320 1440 1560
Time (min)

12
Hydrograph Report
Hydraflow Hydrographs Extension for AutoCADO Civil 3D® 2009 by Autodesk, Inc. v6.066
Friday, Oct 22, 2021
Hyd. No. 2
SCM Post -Developed
Hydrograph type =
SCS Runoff
Peak discharge
= 11.52 cfs
Storm frequency =
2 yrs
Time to peak
= 716 min
Time interval =
2 min
Hyd. volume
= 23,754 cuft
Drainage area =
2.900 ac
Curve number
= 87.6
Basin Slope =
0.0 %
Hydraulic length
= 0 ft
Tc method =
USER
Time of conc. (Tc)
= 5.00 min
Total precip. =
3.69 in
Distribution
= Type II
Storm duration =
24 hrs
Shape factor
= 484
SCM Post -Developed
Hyd. No. 2 -- 2 Year
10.00
Were
�re
4.00
2.00
Q (cfs)
12.00
10.00
M
MIX
4.00
2.00
0.00 ` I I^� - 0.00
0 120 240 360 480 600 720 840 960 1080 1200 1320
Hyd No. 2 Time (min)

Hydrograph
Report
13
Hydraflow Hydrographs Extension forAutoCAD® Civil 31DO2009 byAutodesk, Inc. v6.066
Friday, Oct 22, 2021
Hyd. No. 3
Post Through SCM
Hydrograph type
= Reservoir
Peak discharge
= 0.000 cfs
Storm frequency
= 2 yrs
Time to peak
= 862 min
Time interval
= 2 min
Hyd. volume
= 0 cuft
Inflow hyd. No.
= 2 - SCM Post -Developed
Max. Elevation
= 379.64 ft
Reservoir name
= BMP Pond
Max. Storage
= 9,664 cuft
Storage Indication method used. Exfiltration extracted from Outflow
Post Through SCM
Q (cfs) Hyd. No. 3 -- 2 Year Q (cfs)
12.00 - 12.00
10.00 10.00
8.00 — 8.00
6.00 6.00
4.00 4.00
I
2.00 2.00
0.00 0.00
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560 1680
Time (min)
Hyd No. 3 Hyd No. 2 ® Total storage used = 9,664 cult

14
Hydrograph Report
Hydraflow Hydrographs Extension for AutoCADO Civil 3DO 2009 by Autodesk, Inc. v6.066
Hyd. No. 4
SCM Post -Developed
Bypass
Hydrograph type
= SCS Runoff
Storm frequency
= 2 yrs
Time interval
= 2 min
Drainage area
= 1.910 ac
Basin Slope
= 0.0 %
Tc method
= USER
Total precip.
= 3.69 in
Storm duration
= 24 hrs
Q (cfs)
W ItM
1.00
M
Friday, Oct 22, 2021
Peak discharge = 1.794 cfs
Time to peak
= 722 min
Hyd. volume
= 5,359 cuft
Curve number
= 62.9
Hydraulic length
= 0 ft
Time of conc. (Tc)
= 10.00 min
Distribution
= Type II
Shape factor
= 484
SCM Post -Developed Bypass
Hyd. No. 4 -- 2 Year
120 240 360 480 600 720 840 960
Hyd No. 4
Q (cfs)
2.00
1.00
0.00
1080 1200 1320 1440 1560
Time (min)

17
Hydrograph Summary Rep OY aflow Hydrographs Extension for AUtoCADV 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)
Inflow
hyd(s)
Maximum
elevation
(ft)
Total
strge used
(cuft)
Hydrograph
description
1
SCS Runoff
7.302
2
728
27,532
----
- —
---
SCM Pre -Developed
2
SCS Runoff
18.88
2
716
40,027
------
--
—
SCM Post -Developed
3
Reservoir
0.000
2
974
0
2
380.70
17,359
Post Through SCM
4
SCS Runoff
4.805
2
722
12,822
—
-
SCM Post -Developed Bypass
6
SCS Runoff
0.000
2
n/a
0
-
------
1.0 Post -Developed to SCM
7
Reservoir
0.000
2
n/a
0
6
378.00
0.000
1.0inPost Through SCM
Infiltration.gpw
Return Period: 10 Year
Friday, Oct 22, 2021

Hydrograph Report
Hydraflow Hydrographs Extension for AUtoCADO Civil 3DO 2009 by Autodesk, Inc. v6.066
Hyd. No. 1
SCM Pre -Developed
Hydrograph type =
SCS Runoff
Storm frequency =
10 yrs
Time interval =
2 min
Drainage area =
4.810 ac
Basin Slope =
0.0 %
Tc method =
USER
Total precip. =
5.45 in
Storm duration =
24 hrs
MIX
4.00
WIR
SCM Pre -Developed
Hyd. No. 1 -- 10 Year
120 240 360 480 600 720 840
Hyd No. 1
18
Friday, Oct 22, 2021
Peak discharge = 7.302 cfs
Time to peak =
728 min
Hyd. volume =
27,532 cuft
Curve number
= 59.7
Hydraulic length
= 0 ft
Time of conc. (Tc)
= 20.80 min
Distribution
= Type II
Shape factor
= 484
Q (cfs)
8.00
. 1H
4.00
2.00
0.00
960 1080 1200 1320 1440 1560
Time (min)

19
Hydrograph Report
Hydraflow Hydrographs Extension for AutoCADO Civil 3D® 2009 by Autodesk, Inc. v6.066
Hyd. No. 2
SCM Post -Developed
Hydrograph type = SCS Runoff
Storm frequency = 10 yrs
Time interval
= 2 min
Drainage area
= 2.900 ac
Basin Slope
= 0.0 %
Tc method
= USER
Total precip.
= 5.45 in
Storm duration
= 24 hrs
SCM Post -Developed
Friday, Oct 22, 2021
Peak discharge = 18.88 cfs
Time to peak
= 716 min
Hyd. volume
= 40,027 cuft
Curve number
= 87.6
Hydraulic length
= 0 ft
Time of conc. (Tc)
= 5.00 min
Distribution
= Type II
Shape factor
= 484
Q (cfs) Hyd. No. 2 -- 10 Year Q (cfs)
21.00 21.00
-
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
0 120 240 360 480 600 720 840 960 1080 1200
Hyd No. 2 Time (min)

K11
Hydrograph Report
Hydraf low Hydrographs Extension forAutoCAD® Civil 3DO2009 byAutodesk, Inc. v6.066
Hyd. No. 3
Post Through SCM
Hydrograph type = Reservoir
Storm frequency = 10 yrs
Time interval = 2 min
Inflow hyd. No. = 2 - SCM Post -Developed
Reservoir name = BMP Pond
Storage Indication method used. Exfiltration extracted from Outflow.
Post Through SCM
Peak discharge
Time to peak
Hyd. volume
Max. Elevation
Max. Storage
Friday, Oct 22, 2021
= 0.000 cfs
= 974 min
= 0 cuft
= 380.70 ft
= 17,359 cuft
Q (cfs) Hyd. No. 3 -- 10 Year Q (cfs)
21.00 21.00
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 1 - —j. -- _ 0.00
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Time (min)
Hyd No. 3 Hyd No. 2 ® Total storage used = 17,359 cuft

Hlydrograph Report
Hydraf low Hydrographs Extension for AutoCAD® Civil 3DO 2009 by Autodesk, Inc. v6.066
Hyd. No. 4
SCM Post -Developed
Bypass
Hydrograph type
= SCS Runoff
Storm frequency
= 10 yrs
Time interval
= 2 min
Drainage area
= 1.910 ac
Basin Slope
= 0.0 %
Tc method
= USER
Total precip.
= 5.45 in
Storm duration
= 24 hrs
4.00
3.00
2.00
1.00
0.00
0 120 240
Hyd No. 4
21
Friday, Oct 22, 2021
Peak discharge = 4.805 cfs
Time to peak
= 722 min
Hyd. volume
= 12,822 cuft
Curve number
= 62.9
Hydraulic length
= 0 ft
Time of conc. (Tc)
= 10.00 min
Distribution
= Type II
Shape factor
= 484
SCM Post -Developed Bypass
Hyd. No. 4 -- 10 Year
360 480 600 720 840
Q (cfs)
5.00
4.00
3.00
2.00
1.00
0.00
960 1080 1200 1320 1440 1560
Time (min)

24
Hydrograph
Summary
Re PC I-rydraflow
Hydrographs
Extension
for AUtoCAD@
Civil 3D® 2009 by Autodesk, Inc. v6.066
Hydrograph
Peak
Time
Time to
Hyd.
Inflow
Maximum
Total
Hydrograph
Hyd.
No.
type
flow
interval
peak
volume
hyd(s)
elevation
strge used
description
(origin)
(cfs)
(min)
(min)
(cult)
(ft)
(cult)
1
SCS Runoff
17.60
2
728
61,984
- --
------
------
SCM Pre -Developed
2
SCS Runoff
30.49
2
716
66,764
-----
------
---
SCM Post -Developed
3
Reservoir
18.87
2
720
13,670
2
381.33
22,439
Post Through SCM
4
SCS Runoff
10.59
2
720
27,561
-----
--
---
SCM Post -Developed Bypass
6
SCS Runoff
0.000
2
n/a
0
------
- --
----
1.0 Post -Developed to SCM
7
Reservoir
0.000
2
n/a
0
6
378.00
0.000
1.0inPost Through SCM
Infiltration.gpw
Return Period: 100 Year
Friday, Oct 22, 2021

Hydrograph Report
Hydraflow Hydrographs Extension for AutoCAD® Civil 3D@ 2009 by Autodesk, Inc. v6.066
Hyd. No. 1
SCM Pre -Developed
Hydrograph type =
SCS Runoff
Storm frequency =
100 yrs
Time interval =
2 min
Drainage area =
4,810 ac
Basin Slope =
0.0 %
Tc method =
USER
Total precip. =
8.25 in
Storm duration =
24 hrs
15.00
12.00
• 0H
. 0H
3.00
SCM Pre -Developed
Hyd. No. 1 -- 100 Year
25
Friday, Oct 22, 2021
Peak discharge = 17.60 cfs
Time to peak =
728 min
Hyd. volume
= 61,984 cuft
Curve number
= 59.7
Hydraulic length
= 0 ft
Time of conc. (Tc)
= 20.80 min
Distribution
= Type II
Shape factor
= 484
Q (cfs)
18.00
15.00
12.00
we]
3.00
0.00
120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Hyd No. 1 Time (min)

26
Hydrograph Report
Hydraflow Hydrographs Extension for AutoCADO Civil 3D® 2009 by Autodesk, Inc. v6.066
Hyd. No. 2
SCM Post -Developed
Hydrograph type =
SCS Runoff
Storm frequency =
100 yrs
Time interval =
2 min
Drainage area =
2.900 ac
Basin Slope =
0.0 %
Tc method =
USER
Total precip. =
8.25 in
Storm duration =
24 hrs
SCM Post -Developed
Friday, Oct 22, 2021
Peak discharge = 30.49 cfs
Time to peak
= 716 min
Hyd. volume
= 66,764 cuft
Curve number
= 87.6
Hydraulic length
= 0 ft
Time of conc. (Tc)
= 5.00 min
Distribution
= Type II
Shape factor
= 484
Q (cfs) Hyd. No. 2 -- 100 Year Q (cfs)
35.00 - 35.00
30.00 30.00
25.00 25.00
20.00 - 20.00
15.00 - 15.00
10.00 10.00
5.00 5.00
0.00 0.00
0 120 240 360 480 600 720 840 960 1080 1200
Hyd No. 2 Time (min)
•

Hydrograph Report
Hydraflow Hydrographs Extension for AutoCADO Civil 3D® 2009 by Autodesk, Inc. v6.066
Hyd. No. 3
Post Through SCM
Hydrograph type =
Reservoir
Storm frequency =
100 yrs
Time interval =
2 min
Inflow hyd. No. =
2 - SCM Post -Developed
Reservoir name =
BMP Pond
Storage Indication method used. Exfiltration extracted from Outflow.
Post Through SCM
27
Friday, Oct 22, 2021
Peak discharge = 18.87 cfs
Time to peak = 720 min
Hyd. volume = 13,670 cuft
Max. Elevation = 381.33 ft
Max. Storage = 22,439 cuft
Q (cfs) Hyd. No. 3 -- 100 Year Q (cfs)
35.00 35.00
30.00 30.00
25.00 - 25.00
20.00 20.00
15.00 — 15.00
10.00 10.00
5.00 5.00
0.00 0.00
0 120 240 360 480 600 720 840
Time (min)
Hyd No. 3 Hyd No. 2 ® Total storage used = 22,439 cult

pl-
Hydrograph Report
Hydraflow Hydrographs Extension for AutoCADO Civil 3D® 2009 byAutodesk, Inc. v6.066
Hyd. No. 4
SCM Post -Developed
Bypass
Hydrograph type
= SCS Runoff
Storm frequency
= 100 yrs
Time interval
= 2 min
Drainage area
= 1.910 ac
Basin Slope
= 0.0 %
Tc method
= USER
Total precip.
= 8.25 in
Storm duration
= 24 hrs
10.00
. IX
4.00
2.00
Friday, Oct 22, 2021
Peak discharge = 10.59 cfs
Time to peak
= 720 min
Hyd. volume
= 27,561 cuft
Curve number
= 62.9
Hydraulic length
= 0 ft
Time of conc. (Tc)
= 10.00 min
Distribution
= Type II
Shape factor
= 484
SCM Post -Developed Bypass
Hyd. No. 4 -- 100 Year
Q (cfs)
12.00
10.00
M
M. We
4.00
2.00
0.00 -+ 1 1 1 �Pp� I I I 1 0.00
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
-- Hyd No. 4 Time (min)

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