SW6231001_Stormwater Design Report_20240424

Bowman
Lancaster
N Parker Church Road
Hoke County, North Carolina
COORDINATE: 35°01 '20.14"N, 79°08'14.20"W
Project No.: 2201 37-01-001
Stormwater Design Report
Prepared By:
Bowman
NORTH CAROLINA
4006 Barrett Drive, Suite 104
Raleigh, NC 27609
ICAIIIo
a •
i
SEAL
: 051571
•
PREPARED FOR: /i' �l 0 ?.
/�'J lllfll 1111���\\\
Lancaster 1 HOA Inc. ��
1184 Fayetteville Road Carlo Pardo, PE
Raeford, NC 28376 NC License No. 051571
George Blackwell 0: [phone]
[phone] [e-mail]
JANUARY 17, 2024
Lancaster -Storm water Design Report 1

Bowman
NORTH CAROLINA
TABLE OF CONTENTS
Stormwater Management Narrative PAGE
• Project Data 3
• Site History 3
• Project Description 4
• Land Disturbance and Impervious Area 4
• Watershed Protection Overlay 4
• Streams 4
• Floodplains 4
• Design Requirements 4
• Methodology 5
• Conclusion 5
Appendix A: Figures 7
• County Soil Survey
• Topography Map
• FEMA Flood Map No. 3710945600J
• Hydrologic Unit Code (HUC)
• Surface Water Classification Map
• NOAA Point Precipitation Frequency Estimates
• SHWT and Infiltration Rate Report
• Pre-Development Drainage Basin Map
• Post-Development Drainage Basin Map
Appendix B: Infiltration Basin Calculations 8
• Design Supplement
• CN Values
• Time of Concentration Calculations
• Infiltration Basin Design
• Hydrographs
• Stormwater Management Details
• Spillway Design
Lancaster -Stormwater Design Report 2 I P a g e

Bowman
NORTH CAROLINA
STORMWATER MANAGEMENT NARRATIVE
This report documents the hydrological and erosion control analysis performed by Bowman
Consulting for the proposed Lancaster residential development in Hoke County, North Carolina.
The report consists of a review of available hydrologic data, methods analysis, development of
existing and proposed hydraulic models, and presentation of the impacts of the proposed
development in the project.
PROJECT DATA
Table 1:Site Information
Project Name Lancaster
Parcel Identification 494560401059
Number (PIN)
Parcel Address 471 N Parker Church Rd
Previous Site Plan Case N/A
Number
Stormwater Regulatory N/A
Basin
River Basin Cape Fear
Total Parcel Area 10.82+ acres
Existing / Proposed EXISTING: 0.09 acres (4,117 SF)
Impervious Area PROPOSED: 2.32 acres (100,880 SF)
Area of Land Disturbance 2.10 acres
TMDLs N/A
Watershed Protection N/A
Overlay
SITE HISTORY
The proposed site is located in Hoke County, North Carolina and is within an unincorporated area
of McLauchlin Township. The site is along N Parker Church Road. The site is adjacent to single-
family home subdivisions on the north and west, and undeveloped wooded space to the south
and east.
Soils located within the project site as defined by NRCS (National Resources Conservation
Service) are described in Table 2.
Lancaster -Storm water Design Report 3 I P a g e

Bowman
NORTH CAROLINA
Table 2:Hydrologic Soil Groups
Group Description
WaB Wagram loamy sand, 0 to 6 percent slopes
NoB Norfolk loamy sand, 2 to 6 percent slopes
BaD Blaney loamy sand, 8 to 15 percent slopes
BaB Blaney loamy sand, 2 to 8 percent slopes
According to the Web Soil Survey, 65% of the subject site falls within the hydrologic soil group A
and 35% of the site falls within hydrologic soil group C. Group A soils have a high infiltration rate
when thoroughly wet and consist mostly of well drained sands or gravelly sands. Group C soils
have a slow infiltration rate when thoroughly wet and are moderately fine textured or fine
textured.
PROJECT DESCRIPTION
Lancaster 1 HOA Inc. is proposing to develop the +10.82 acre parcel with a new 16 lot
residential development, as well as supporting infrastructure.
LAND DISTURBANCE AND IMPERVIOUS AREA
The project includes approximately 2.10 acres of land disturbance on the northern parcel.
Approximately 2.32 acres (+ 100,880 SF) of impervious area is proposed for the lots, pavement,
sidewalk, and mail kiosk.
WATERSHED PROTECTION OVERLAY
This site is not located in a watershed protection overlay.
STREAMS
There are no streams located on site.
FLOODPLAINS
The project is shown to be located in Zone 'X' per FEMA Panel 3710945600J located in Appendix
A. Because the post-developed conditions will not result in a net increase in runoff from the site,
no adverse downstream impacts are expected to occur.
DESIGN REQUIREMENTS
Stormwater design was based on the standards presented in the North Carolina Department of
Environmental Quality (NC DEQ) Stormwater Design Manual.
Lancaster -Stormwater Design Report 4 I P a g e

Bowman
NORTH CAROLINA
The NC DEQ requires that post-development discharge rates for the site are not to exceed pre-
development discharge rates for the one (1)-year and ten (10)-year twenty-four (24)-hour
duration storm event.
Stormwater quantity control will be provided by one new infiltration basin as part of the
development.
METHODOLOGY
Hydrology and storm water modeling calculations were performed using the latest version of
Hydraflow modeling software. Simulations were set up based on information provided within the
North Carolina Department of Environmental Quality (NC DEQ) Stormwater Design Manual.
The Soil Conservation Service (NRCS TR-55) hydrologic method was utilized for the estimation of
stormwater runoff peak rates and the generation of hydrographs for the routing of stormwater
flows. Input and results can be found summarized in tables throughout this report and in the
appendices.
CONCLUSION
Stormwater design was based on the standards presented in the North Carolina Department of
Environmental Quality (NC DEQ) Stormwater Design Manual.
Peak Runoff Analysis
• Pre-Development Conditions
The site is currently residential with a few buildings and dirt driveways, but is primarily open and
wooded space. The site is planned for residential development. For the purposes of SCM design,
one drainage area was analyzed in this report with its own study point, composite runoff curve
number and single point of analysis.
SCM#1 Pre-Developed Area covers 9.55 acres (+416,055 SF) and directs water to the southeast
corner of the site.
Drainage Area #1 drains off-site and eventually to Puppy Creek. The characteristics for the pre-
development condition are shown below and additional calculations such as can be found in
Appendix B. A drainage map identifying the basin can also be found in Appendix B.
Table 5:Pre-Development Drainage Area Summaries
Area Composite Time of
Basin ID [acres] Curve Concentration
Number (CN) (Tc) [min.]
SCM #1 Pre-Developed Area 9.55 60.4 22.3
• Post-Development Conditions
The post-development condition contains one drainage area to the infiltration basin.
Lancaster -Stormwater Design Report 5 I P a g e

Bowman
NORTH CAROLINA
Drainage Area #1 consists of the proposed residential development area and some offsite area.
The drainage area collects runoff with curb inlets, and drainage pipes that connect to the
proposed infiltration basin SCM.
The characteristics for the post-development drainage areas are shown below and calculations
can be found in Appendix B. A drainage map identifying the area can be found in Appendix A.
Table 6:Post Development Area Summaries
Area
Composite Time of
Basin ID [acres] Curve Concentration
Number (CN) (Tc) [min.]
SCM #1 Post-Developed Area 9.04 73.2 5
• Comparison of Peak Discharges
The pre- and post- development peak discharges are shown below. Full calculations and
hydrographs can be found on Appendix B.
Table 8: Total Site Downstream Impact-Normal Condition
Pre-Dev. Post-Dev. w/o Detention Post-Dev. w/ Detention
Peak Discharge Rate Peak Discharge Rate Peak Discharge Rate
Storm Event (cfs) (cfs) (cfs)
1-yr 24-hr _ 2.112 13.62 _ 0.000
10-yr 24-hr 15.12 40.47 1.315
100-yr 24-hr 36.22 76.68 46.12
Lancaster -Storm water Design Report Wage

Bowman
NORTH CAROLINA
APPENDIX A
Figures
County Soil Survey
Topography Map
FEMA Flood Map
Hydrologic Unit Code (HUC)
Surface Classification Map
NOAA Point Precipitation Frequency Estimates
SHWT and Infiltration Rates Report
Pre-Development Drainage Basin Map
Post-Development Drainage Basin Map
Lancaster -Storm water Design Report 7 I P a g e

Hydrologic Soil Group—Hoke County, North Carolina
8
F
669840 669920 670000 670080 670160 670240 670320 670400 670480 670560
35°1'28"N . 35°1'28"N
- .1!
•
a
.0
0 JT
• 51
i*Nos 114. Pep)
8
- , \ ...........H1 .
11 r..
NoB -
4
I 'f ,ram —
t
�01 NE 541oR RD- wE nd ate thIlE -2,ca0 °
35°1'12"N I 6� 35°1'12'N
669840 669920 670000 670080 670160 670240 670320 670400 670480 670560
3 3
b. Map Scale:1:3,530 if printed on A landscape(11"x 8.5")sheet. ,
N Meters
0 50 100 200 300
Feet
0 150 300 600 900
Map projection:Web Mercator Corner coordinates:WG584 Edge tics:UTM Zone 17N WOiS84
USDA Natural Resources Web Soil Survey 9/1/2023
Conservation Service National Cooperative Soil Survey Page 1 of 4

Hydrologic Soil Group—Hoke County, North Carolina
MAP LEGEND MAP INFORMATION
Area of Interest(AOI) p c The soil surveys that comprise your AOI were mapped at
Area of Interest(AOI) 1:24,000.
0 C/D
Soils • D Warning:Soil Map may not be valid at this scale.
Soil Rating Polygons
l A p Not rated or not available Enlargement of maps beyond the scale of mapping can cause
misunderstanding of the detail of mapping and accuracy of soil
n A/D Water Features line placement.The maps do not show the small areas of
Streams and Canals contrasting soils that could have been shown at a more detailed
n B scale.
Transportation
Q B/D
r4-1. Rails Please rely on the bar scale on each map sheet for map
n C measurements.
ti Interstate Highways
C/D US Routes Source of Map: Natural Resources Conservation Service
Web Soil Survey URL:
0 D Major Roads Coordinate System: Web Mercator(EPSG:3857)
n Not rated or not available Local Roads
Maps from the Web Soil Survey are based on the Web Mercator
Soil Rating Lines Background projection,which preserves direction and shape but distorts
• • A distance and area.A projection that preserves area,such as the
1111 Aerial Photography Albers equal-area conic projection,should be used if more
• • A/D accurate calculations of distance or area are required.
^r B This product is generated from the USDA-NRCS certified data as
.v B/D of the version date(s)listed below.
• r C Soil Survey Area: Hoke County, North Carolina
Survey Area Data: Version 20,Sep 8,2022
• • C/D
Soil map units are labeled(as space allows)for map scales
• • D 1:50,000 or larger.
• w Not rated or not available Date(s)aerial images were photographed: Apr 23,2022—Apr
Soil Rating Points 27,2022
p A The orthophoto or other base map on which the soil lines were
compiled and digitized probably differs from the background
O A/D imagery displayed on these maps.As a result,some minor
• B shifting of map unit boundaries may be evident.
• B/D
USDA Natural Resources Web Soil Survey 9/1/2023
Conservation Service National Cooperative Soil Survey Page 2 of 4

Hydrologic Soil Group—Hoke County, North Carolina
Hydrologic Soil Group
Map unit symbol Map unit name Rating Acres in AOI Percent of AOI
BaB Blaney loamy sand,2 to C 7.6 22.4%
8 percent slopes
BaD Blaney loamy sand,8 to C 7.3 21.5%
15 percent slopes
JT Johnston loam ND 0.7 2.1%
NoB Norfolk loamy sand,2 to A 3.4 10.0%
6 percent slopes
WaB Wagram loamy sand,0 A 15.0 44.0%
to 6 percent slopes
Totals for Area of Interest 34.0 100.0%
USDA Natural Resources Web Soil Survey 9/1/2023
Conservation Service National Cooperative Soil Survey Page 3 of 4

Hydrologic Soil Group—Hoke County,North Carolina
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
Component Percent Cutoff.None Specified
Tie-break Rule: Higher
USDA Natural Resources Web Soil Survey 9/1/2023
Conservation Service National Cooperative Soil Survey Page 4 of 4

Y Liv,
1
e..,
7,;-• Z,'. ' .' '..'."2.1%‘-:
:.--
...e
,
Nicholson Creek - Nicholson Creek •-• - ' -• ‘. --- Nicholson Creek Clifdal.
.. 1 iD . . . . .
/
1...
—
' -
Johnsons Mill
1
.,.<1.-.)
_ -
. , If•,_--J-I'4 •
, •-•. _ _.:__-r--.
. a
--;1
-,.., • ".., I
.
Nicholson Creek -i Nicholson Creek- - 7) - 'IN i cho I s on CreEk -t-- - Clifdal.
,...
_ . _. ..
5-:
... -,
,-, •-
• ..

National Flood Hazard Layer FIRMette = FEMA Legend_
79°8'25"W 35°1'36"N SEE FIS REPORT FOR DETAILED LEGEND AND INDEX MAP FOR FIRM PANEL LAYOUT
r
•11 041
�� \ Without Base Flood Elevation(BFE)
'• • • I ` Zone A,V.A99
y '1 With BFE or Depth Zone AE,AO,AH,VE,AR
Nc6 SPECIAL FLOOD
_ - �- HAZARD AREAS Regulatory Floodway
. ...-"(f\ \*N‘IN\
• _... • 0.2%Annual Chance Flood Hazard,Areas
r11 r i ,.Fi� of 1%annual chance flood with average
0� �i 4.`7 depth less than one foot or with drainage
I OA
• • areas of less than one square mile zone x
• , , i,,,►�/ � ' i y�� Future Conditions 1%Annual
� ' , • , • \�'1, . Chance Flood Hazard zonex
• • ', 4 ,r 4.0 " Area with Reduced Flood Risk due to
j • '• 110. %. ��G OTHER AREAS OF Levee.See Notes.zonex
f ' , r��et 1' Zone AE ` FLOOD HAZARD �� Area with Flood Risk due to Leveezone D
• � C F� � '�, , ! ,
. \ NO SCREEN Area of Minimal Flood Hazard zonex
l I / ' • \ t\ _
Effective LOMRs
lL_ • ♦ t \ 1 } OTHER AREAS Area of Undetermined Flood Hazard Zone D
I.
410
#r
�• •_ , 0" .►tklik • Zone AE IS 1t GENERAL ----- Channel,Culvert,or Storm Sewer
•
I� •
STRUCTURES I I I I I I I Levee,Dike,or Floodwall
t
• I. .
d �` 1 O 20.2 Cross Sections with 1%Annual Chance
HOKE COUNTY 1 t�•s Water Surface Elevation
• _ i \ ' a - Coastal Transect
• 4 ' -� _ s - Base Flood Elevation Line(BFE)
3 to 0397� AREA OF MINIMAL FLOOD HAZARD '� Limit of Study
. Jurisdiction Boundary
• ZOn X ' FLOOt1'���Y --- Coastal Transect Baseline
•
-f„ 3710945600J •• 37109466.. - F�
OTHER - - Profile Baseline
01J• �� .y�..r.• . FEATURES
� Hydrographic Feature
eff iri . /17/2006 01 eff. 10/17/21)r i t,
• - ail Digital Data Available N
\\\.
ArA.Pan � No Digital Data Available
�,, .• •. 0 r •I y Unmapped
'� 1104410°.—
r'
•
yy ' ^�� The pin displayed on the map is an approximate
A y. • ; �' 4.4.
i �� .� point selected by the user and does not represent
111,
• A .� i�
• an authoritative property location.
♦rai �. This map complies with FEMA's standards for the use of
�� • �• o. digital flood maps if it is not void as described below.
�/}' • j • • j iv __► _ The basemap shown complies with FEMA's basemap
• • • • . :
• °if µ ` accuracy standards
• a• •.J 41 • • The flood hazard information is derived directly from the
• authoritative NFHL web services provided by FEMA.This map
` , . �• • i I •sr3 * r I' , • ` ,�2,0 was exported on 9/1/2023 at 2:39 PM and does not
` 1•' .• i. 6 reflect changes or amendments subsequent to this date and
♦_ y�. tit
11•
time.The NFHL and effective information may change or
, � •; 4 • �' r••, •I•�• ^• �� W'.
• ♦ become superseded by new data over time.
T11' 1• v - �' • This map image is void if the one or more of the following map
: . *
1 • i - •, a, elements do not appear:basemap imagery,flood zone labels,
# - _ t� •
legend,scale bar,map creation date,community identifiers,
• FIRM panel number,and FIRM effective date.Map images for
ge Feet 1:6 79°7'48"W 35°1'7"N unmapped and unmodernized areas cannot be used for
0 250 500 1,000 1,500 2,000 '�0� regulatory purposes.
Basemap Imagery Source:USGS National Map 2023

73
a
8
C. h11 Ct
co
(1 of 2) ► LO X
12-Digit HUC(Subwatershed)
12-Digit Name: Lower Puppy Creek
Z 12-Digit Code: 030300040606
a i 10-Digit Name: Rockfish Creek
vc
co 10-Digit Code: 0303000406
0
8-Digit Code: 03030004
A
River Basin: Cape Fear
lie Dr a 12-Digit Area(ac): 11.636.32
o I ,� on 10 R4
Zoom to ns
Tv
illMir
c`o
co
AO jt _ Id
0
al o
o0 y
�SSenro`Nec
0O, o

i
DEQ
r,:, NC Surface Water Classifications NC Classifications Website Report an Issue
�viP
I,., y 1
QStream Details ( Lec:crd )( Layers )\ Pr nt )
a Oe 4 ®a
O O 0GS
ca'ralrot 01 g. f,ni -a Oi
oi
to F4
XQ- C2
I y _it Familyo a Surface Water Classifications:
6
♦t N R
gar `y''" ,� ; Surface Water Classifications: 0] X
Facrs
o �' e Stream Index: 18-31 -19
��
ir
to Cx ��,a �o\`9 Stream Index: 18-31 19
0
Stream Name: Puppy Creek Stream Name: Puppy Creek
o Description: From source to Rockfish Creek
Description: From source to Rockfish Creek
:, Classification. C
p` Date of Class.: June 30, 1973 Classification: C
'+e`•d'‘ Pk' What does this Class_mean? v _,v Date of Class.: June 30, 1973
F/ ,.0.,.v 1,
River Basin: Cape Fear
0What does this Class. mean? View
i
a
7 Johnsons
3CZzon, t Mill -'-' River Basin: Cape Fear
7.
t,
Q
,0'3�
L`.

9/1/23,2:37 PM Precipitation Frequency Data Server
NOAA Atlas 14,Volume 2,Version 3
vL Location name: Raeford,North Carolina,USA* ''''
i X1 Latitude:35.022°, Longitude: -79.1365° V
none
„ .175,i Elevation:247 ft**
4' *source:ESRI Maps
-.nu° **source:USGS
POINT PRECIPITATION FREQUENCY ESTIMATES
G.M.Bonnin,D.Martin,B.Lin,T.Parzybok,M.Yekta,and D.Riley
NOAA,National Weather Service,Silver Spring,Maryland
PF tabular I PF graphical I Maps & aerials
PF tabular
PDS-based point precipitation frequency estimates with 90% confidence intervals (in inches)1
Average recurrence interval(years)
Duration 1 2 I 5 10 25 50 100 200 I 500 1000
5-min 0.436 0.514 0.600 0.664 0.741 0.796 0.849 0.899 0.960 1.01
(0.396-0.483) (0.467-0.570) (0.544-0.665) (0.601-0.734) (0.668-0.817) (0.716-0.877) (0.759-0.934) (0.800-0.988) (0.847-1.06) (0.883-1.11)
10-min 0.696 0.822 0.960 1.06 1.18 1.27 1.35 1.42 1.52 1.59
(0.632-0.771) (0.747-0.912) (0.872-1.06) (0.962-1.17) (1.06-1.30) (1.14-1.40) (1.21-1.48) (1.27-1.57) (1.34-1.67) (1.39-1.74)
15-min 0.870 1.03 1.22 1.34 1.50 I 1.61 1.70 1.80 1.91 1.99
(0.790-0.963) (0.939-1.15)I (1.10-1.35) (1.22-1.48) (1.35-1.65) (1.44-1.77) (1.52-1.88) (1.60-1.98) I (1.69-2.10) (1.74-2.19)
30-min 1.19 1.43 1.73 1.95 2.22 2.42 2.61 2.80 1 3.04 3.22
(1.08-1.32) (1.30-1.58) (1.57-1.91) (1.76-2.15) (2.00-2.44) (2.18-2.66) (2.34-2.87) (2.49-3.08) (2.68-3.34) (2.83-3.54)
60-min 1.49 1.79 2.21 2.54 2.95 3.28 3.60 3.92 4.36 4.71
(1.35-1.65) (1.63-1.99) (2.01-2.45) (2.30-2.80) (2.66-3.26) (2.95-3.61) I (3.22-3.96) (3.49-4.31) (3.85-4.80) (4.12-5.18)
2-hr 1.73 2.10 2.64 3.05 I 3.61 4.05 4.50 4.96 5.58 6.07
(1.56-1.95) (1.89-2.36) (2.37-2.96) (2.74-3.42) (3.22-4.05) (3.60-4.54) (3.97-5.04) (4.35-5.55) (4.85-6.24) (5.23-6.79)
3-hr 1.84 2.22 2.81 3.27 3.92 4.44 4.99 5.56 6.37 7.02
(1.65-2.07) (2.00-2.51) (2.52-3.16) (2.93-3.68) (3.48-4.40) (3.93-4.98) (4.38-5.59) (4.85-6.22) , (5.48-7.13) (5.98-7.85)
6-hr 2.19 2.65 3.35 3.92 4.70 5.34 6.02 6.74 7.76 8.58
(1.98-2.45) (2.40-2.96) (3.03-3.73) (3.52-4.35) (4.20-5.21) (4.74-5.92) (5.30-6.66) (5.88-7.44) (6.68-8.55) (7.31-9.46)
12-hr 2.58 3.13 3.97 4.66 5.64 6.45 7.31 8.24 9.57 10.7
(2.33-2.88) I (2.83-3.49) (3.58-4.43) (4.18-5.19) (5.02-6.25) (5.70-7.14) (6.40-8.08) (7.14-9.09) (8.16-10.6) (8.98-11.7)
24-h r 3.04 3.68 4.67 5.45 6.54 7.41 8.30 9.24 10.5 I 11.5
(2.82-3.28) (3.42-3.98) (4.33-5.04) (5.04-5.88) (6.02-7.05) (6.80-7.98) (7.60-8.96) (8.43-9.96) (9.55-11.3) (10.4-12.5)
2-day 3.53 4.26 5.36 6.23 7.44 8.40 9.40 10.4 11.8 13.0
(3.29-3.80) (3.97-4.58) (4.98-5.76) (5.78-6.70) (6.87-7.98) (7.74-9.02) (8.62-10.1) (9.53-11.2) (10.8-12.7) (11.7-14.0)
3-day 3.75 4.52 5.65 6.55 7.79 8.78 9.80 10.9 12.3 13.5
(3.50-4.02) (4.22-4.84) (5.27-6.05) (6.09-7.01) (7.22-8.33) (8.11-9.39) (9.03-10.5) (9.96-11.6) I (11.2-13.2)I (12.2-14.4)
4-day 3.97 4.78 5.94 6.87 8.14 9.16 10.2 11.3 I 12.8 14.0
(3.72-4.24) (4.48-5.10) (5.55-6.34) (6.41-7.32) (7.57-8.68) 1 (8.49-9.76) (9.43-10.9) (10.4-12.1) (11.7-13.7) (12.7-14.9)
7-day 4.61 5.52 6.78 7.79 9.16 10.3 11.4 12.5 14.1 1 15.4
(4.31-4.93) (5.16-5.90) (6.33-7.26) (7.26-8.32) (8.51-9.79) (9.50-11.0) (10.5-12.2) (11.6-13.4) (13.0-15.2) (14.1-16.5)
10-day 5.28 6.30 7.63 I 8.66 10.1 11.2 12.3 I 13.4 14.9 16.1
(4.97-5.62) (5.93-6.70) (7.16-8.10) (8.13-9.19) (9.41-10.7) (10.4-11.8) (11.4-13.0) (12.4-14.2) (13.8-15.9) (14.8-17.2)
20-day 7.12 I 8.44 10.0 11.3 13.0 14.3 15.7 17.0 18.9 20.3
(6.72-7.56) (7.96-8.96) (9.46-10.7) (10.6-12.0) (12.2-13.8) r(13.4-15.2) (14.6-16.6) (15.8-18.1) i (17.5-20.1) (18.7-21.6)
30-day 8.86 10.4 12.2 13.6 15.4 16.8 18.2 19.6 21.4 I 22.8
(8.38-9.38) (9.88-11.1) (11.6-12.9) (12.8-14.4) (14.5-16.3) (15.8-17.8) (17.0-19.3) (18.3-20.8) (19.9-22.7) (21.2-24.3)
45-day 11.2 13.2 15.2 16.7 18.6 20.1 21.6 23.0 24.9 26.3
(10.6-11.8) (12.5-13.9) (14.3-16.0) (15.8-17.6) (17.6-19.7) (19.0-21.3) (20.3-22.8) (21.6-24.4) (23.3-26.4) (24.6-28.0)
60-day 13.4 15.7 17.9 19.6 21.7 23.4 24.9 26.5 28.5 30.0
(12.7-14.1) (14.9-16.5) (17.0-18.9) i (18.6-20.6) (20.6-22.9) I (22.1-24.6) (23.5-26.3) I (24.9-27.9) (26.8-30.1) (28.1-31.7)
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 NOAAAtlas 14 document for more information.
Back to Top
PF graphical
https://hdsc.nws.noaa.gov/pfds/pfds_printpage.html?lat=35.0220&Ion=-79.1365&data=depth&units=english&series=pds 1/4

9/1/23,2:37 PM Precipitation Frequency Data Server
PDS-based depth-duration-frequency (DDF) curves
Latitude: 35.0220°, Longitude: -79.1365°
30 - Average recurrence
interval
(years)
25 -
c - 1
c 20 - — 2
c 5cv
15 - __A — 25
50
a 10 — 100
200
tL 5 - Ill 500
-lr
— 1000
0-
c c c c c ; >. >,>, >, >, >, >. >,>.
• - L L r r t ro ro ro ro ro ro ro ro ro
A rn lb ry V -O "O"O 7 17 7 7 7 17
, A A4 N
O rn $ Duration Ni O1 N rrnn v V)
30 - -
25
c
Duration
L 20PIII -
cu '_� — 5-min — 2-day
v
c 15 _� J� - 10-min — 3-day
•y -�� 15 nun — 4-day
.a 10 - � � — 30 min — 7-day
ai
--- — 60-nun — 10-day
a �� — 2-hr — 20-day
5 -�� —� — 3-hr — 30-day
— 6-hr - 45-day
0 - — 12-hr — 60-day
i i — 24-hr
1 2 5 10 25 50 100 200 500 1000
Average recurrence interval (years)
NOAA Atlas 14,Volume 2,Version 3 Created(GMT):Fri Sep 1 18:37:18 2023
Back to Top
Maps & aerials
Small scale terrain
https://hdsc.nws.noaa.gov/pfds/pfds_printpage.html?lat=35.0220&Ion=-79.1365&data=depth&units=english&series=pds 2/4

9/1/23,2:37 PM Precipitation Frequency Data Server
FORT BRAGG
MILITARY
RESERVATION
mmommm
A RPARX
401'
4 a ette
\ 2mi
Large scale terrain
Winston-Salem
• • Durham
Greensboro • Rocky Mount
Raleigh
•
NORTH CAROLINA
Green
•Charlotte Faye ±ill�.
' Jackson
•
[ H CAROLINA a
Wilmington a
100km
60mi
Large scale map
Winston6' lem Greensboro U�uu Rocky Mount
Raleigh
North o eenvl
Carolina
arlotte
F etteville
Jackson
Wilmin
N n
100km
I
60mi
Carolina i
Large scale aerial
https://hdsc.nws.noaa.gov/pfds/pfds_printpage.html?lat=35.0220&Ion=-79.1365&data=depth&units=english&series=pds 3/4

9/1/23,2:37 PM Precipitation Frequency Data Server
Winston-Salem
•
Greensboro Durham .
Raleigh
Gr eenvi
North •
Carol in a
Charlotte
• • Fayett-
Jackson
0
Wilmine�
100km
fl
60mi
Back to Top
US Department of Commerce
National Oceanic and Atmospheric Administration
National Weather Service
National Water Center
1325 East West Highway
Silver Spring,MD 20910
Questions?:[e-mail]
Disclaimer
https://hdsc.nws.noaa.gov/pfds/pfds_printpage.html?lat=35.0220&Ion=-79.1365&data=depth&units=english&series=pds 4/4

9/1/23,2:38 PM Precipitation Frequency Data Server
NOAA Atlas 14,Volume 2,Version 3
i°s" Location name: Raeford,North Carolina,USA* ''''
Imo$; Latitude:35.022°, Longitude: -79.1365° none I
Elevation:247 ft** i
4* *source:ESRI Maps "a
-.nu° **source:USGS "`" y
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/hour)1
Average recurrence interval(years)
Duration
1 2 5 10 25 50 100 - 200 500 1000
5-min 5.23 6.17 7.20 7.97 8.89 9.55 10.2 10.8 11.5 12.1
(4.75-5.80) (5.60-6.84) (6.53-7.98) (7.21-8.81) (8.02-9.80) (8.59-10.5) (9.11-11.2) (9.60-11.9) (10.2-12.7) (10.6-13.3)
10-min 4.18 4.93 5.76 6.37 7.09 7.61 8.09 8.54 9.11 1 9.52
(3.79-4.63) (4.48-5.47) (5.23-6.39) (5.77-7.04) I (6.38-7.81) (6.84-8.38) (7.24-8.90) (7.61-9.40) (8.03-10.0) (8.34-10.5)
15-min 3.48 4.13 4.86 5.38 5.99 6.42 6.82 7.19 7.64 7.96
(3.16-3.85) (3.76-4.58) (4.41-5.39) (4.86-5.94) (5.40-6.60) (5.78-7.07) (6.10-7.50) (6.40-7.90) (6.74-8.40) (6.98-8.76)
30-min 2.39 2.85 3.45 3.89 4.43 4.84 5.22 5.60 6.08 6.45
(2.17-2.64) (2.60-3.17) (3.13-3.83) (3.53-4.30) (4.00-4.89) _(4.35-5.32) (4.67-5.75) (4.98-6.15) (5.37-6.68) (5.65-7.09)
60-min 1.49 1.79 2.21 2.54 2.95 3.28 3.60 3.92 4.36 4.71
(1.35-1.65) (1.63-1.99) (2.01-2.45) (2.30-2.80) (2.66-3.26) I (2.95-3.61) (3.22-3.96) (3.49-4.31) (3.85-4.80) I (4.12-5.18)
2-hr 0.866 1.05 1.32 1.53 1.80 2.03 2.25 2.48 2.79 3.04
(0.779-0.976) (0.945-1.18) (1.19-1.48) (1.37-1.71) (1.61-2.02) (1.80-2.27) (1.99-2.52) (2.18-2.78) (2.42-3.12) (2.62-3.40)
3-hr 0.611 0.740 0.935 1.09 1.30 1.48 1.66 1.85 2.12 2.34
(0.550-0.690) (0.666-0.835) (0.839-1.05) (0.976-1.22) (1.16-1.46) (1.31-1.66) (1.46-1.86) (1.61-2.07) (1.83-2.37) (1.99-2.62)
6-hr 0.365 0.443 0.559 0.653 0.784 1 0.892 1.01 1.12 1.30 1.43
(0.330-0.408) (0.401-0.494) (0.505-0.622) (0.588-0.726) (0.701-0.870)1(0.792-0.988) (0.885-1.11) (0.982-1.24) (1.12-1.43) (1.22-1.58)
12-hr 0.214 0.259 0.329 0.387 0.468 0.535 0.607 0.683 0.794 0.885
(0.193-0.239) (0.234-0.289) (0.297-0.367) (0.347-0.430) (0.416-0.518) (0.473-0.592) (0.531-0.670) (0.592-0.754) (0.677-0.876) (0.745-0.974)
24-hr 0.126 0.153 0.194 0.227 0.272 0.308 0.346 0.384 0.438 0.480
(0.117-0.136) (0.142-0.165) (0.180-0.210) (0.210-0.245) (0.250-0.293) (0.283-0.332) (0.316-0.373) (0.351-0.414) (0.398-0.472) (0.434-0.518)
2-day 0.073 0.088 0.111 0.129 0.154 0.174 0.195 ' 0.217 0.246 0.269
(0.068-0.079) (0.082-0.095) (0.103-0.120) (0.120-0.139) (0.143-0.166) (0.161-0.187) (0.179-0.210)1(0.198-0.233) (0.224-0.265) (0.244-0.290)
3-day 0.052 0.062 0.078 0.090 0.108 0.121 0.136 0.150 0.170 0.186
(0.048-0.055) (0.058-0.067) (0.073-0.084) (0.084-0.097) (0.100-0.115) (0.112-0.130) (0.125-0.145) (0.138-0.161) (0.156-0.183) (0.169-0.200)I
4-day 0.041 0.049 0.061 0.071 0.084 0.095 0.106 0.117 0.133 0.145
(0.038-0.044) (0.046-0.053) (0.057-0.066) (0.066-0.076) (0.078-0.090) (0.088-0.101) (0.098-0.113) (0.108-0.125) (0.121-0.142) (0.132-0.155)
7-day 0.027 0.032 0.040 0.046 0.054 0.061 0.067 0.074 0.084 0.091
(0.025-0.029) (0.030-0.035) (0.037-0.043) (0.043-0.049) (0.050-0.058) (0.056-0.065) (0.062-0.072) (0.068-0.079) (0.077-0.090) (0.083-0.098)
10-day 0.022 0.026 0.031 0.036 0.041 0.046 ' 0.051 0.055 0.062 0.067
(0.020-0.023) (0.024-0.027) (0.029-0.033) (0.033-0.038) (0.039-0.044) (0.043-0.049) (0.047-0.054) (0.051-0.059) (0.057-0.066) (0.061-0.071)
20-day 0.014 0.017 0.020 0.023 0.027 0.029 0.032 0.035 0.039 0.042
(0.014-0.015) (0.016-0.018) (0.019-0.022) (0.022-0.024) (0.025-0.028) (0.027-0.031) (0.030-0.034) (0.033-0.037) (0.036-0.041)i(0.039-0.045)
30-day 0.012 0.014 0.016 0.018 0.021 0.023 0.025 0.027 0.029 0.031
(0.011-0.013) (0.013-0.015) (0.016-0.017) (0.017-0.019) (0.020-0.022) (0.021-0.024) (0.023-0.026) (0.025-0.028) (0.027-0.031) (0.029-0.033)
45-day 0.010 0.012 0.014 0.015 0.017 0.018 0.019 0.021 0.023 0.024
(0.009-0.010) (0.011-0.012) (0.013-0.014) (0.014-0.016) (0.016-0.018) (0.017-0.019) (0.018-0.021) (0.020-0.022) (0.021-0.024) (0.022-0.025)
60-day 0.009 0.010 0.012 0.013 0.015 0.016 0.017 0.018 0.019 0.020
(0.008-0.009) (0.010-0.011) (0.011-0.013) (0.012-0.014) (0.014-0.015) (0.015-0.017) (0.016-0.018) (0.017-0.019) (0.018-0.020)1(0.019-0.022)I
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 Top
PF graphical
https://hdsc.nws.noaa.gov/pfds/pfds_printpage.html?lat=35.0220&Ion=-79.1365&data=intensity&units=english&series=pds 1/4

9/1/23,2:38 PM Precipitation Frequency Data Server
PDS-based intensity-duration-frequency (IDF) curves
Latitude: 35.0220°, Longitude: -79.1365°
Average recurrence
101 -__ interval
(years)
L_
c \\\ — 1
2
7 10° - \ — 5
c
a, \\ — 10
— 25
`o :: TTTE
E E E E N OS ki, N 4 v v-a7 7 v v 77
N A4 N
'n O2 4 m $ Duration Ni 0� N illv V)
101 - •
L_
L
C
— Duration
c — 5-min — 2-day
a
— 1 0-min — 3-day
c 15-min — 4-day
0
— 30-min — 7-day
;° 10-1 - — 60-min — 10-day
•a
D — 2fir — 20-day
cu
a` — 3-hr — 30-day
— 6fir — 45-day
10-2 — 12-hr — 60-day
I I i i I i I — 24fir
1 2 5 10 25 50 100 200 500 1000
Average recurrence interval (years)
NOAA Atlas 14,Volume 2,Version 3 Created(GMT):Fri Sep 1 18:37:50 2023
Back to Top
Maps & aerials
Small scale terrain
https://hdsc.nws.noaa.gov/pfds/pfds_printpage.html?Iat=35.0220&Ion=-79.1365&data=intensity&units=english&series=pds 2/4

9/1/23,2:38 PM Precipitation Frequency Data Server
FORT BRAGG
MILITARY
RESERVATION
mmommm
A RPARX
401'
4 a ette
\ 2mi
Large scale terrain
Winston-Salem
• • Durham
Greensboro • Rocky Mount
Raleigh
•
NORTH CAROLINA
Green
•Charlotte Faye ±ill�.
' Jackson
•
[ H CAROLINA a
Wilmington a
100km
60mi
Large scale map
Winston6' lem Greensboro U�uu Rocky Mount
Raleigh
North o eenvl
Carolina
arlotte
F etteville
Jackson
Wilmin
N n
100km
I
60mi
Carolina i
Large scale aerial
https://hdsc.nws.noaa.gov/pfds/pfds_printpage.html?lat=35.0220&Ion=-79.1365&data=intensity&units=english&series=pds 3/4

9/1/23,2:38 PM Precipitation Frequency Data Server
Winston-Salem
•
Greensboro Durham .
Raleigh
Gr eenvi
North •
Carol in a
Charlotte
• • Fayett-
Jackson
0
Wilmine�
100km
fl
60mi
Back to Top
US Department of Commerce
National Oceanic and Atmospheric Administration
National Weather Service
National Water Center
1325 East West Highway
Silver Spring,MD 20910
Questions?:[e-mail]
Disclaimer
https://hdsc.nws.noaa.gov/pfds/pfds_printpage.html?lat=35.0220&Ion=-79.1365&data=intensity&units=english&series=pds 4/4

Scott Cole,NCLSS
312 Copples Road Ext
Asheboro, NC 27205
[phone]
D&L Engineering, PLLC May 17,2023
Attn: Mr. Lee Humphrey
150 S. Page Street
Southern Pines,NC 28387
Re: Seasonal High-Water Table Identification and Soil Infiltration Rates: N. Parker Church Road, Hoke
County NC parcel 494560401059
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 Department of Environmental Quality Stormwater 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 chroma colors of 2 or less (in Munsell
color notation) in mottles or the horizon matrix, and at times, saturated soil conditions and/or free water
within the soil profile. 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).
SATURATED HYDRAULIC CONDUCTIVITY (Ksat)
Soils evaluated on this property are typical of those within Blaney Loamy Sand Soil series. These soils are
well drained to moderately well drained soils with varying rates of permeability. Infiltration rates are
measured to determine if soil conditions are suitable for the installation of stormwater infiltration devices.
Infiltration rates are measured using a Johnson Constant Head Permeameter. Measurements are recorded
at varying intervals until equilibrium is reached.
The SHWT and Infiltration rates for the stormwater BMP devices are reported in the table below.
BMP Device Site
Test Location SHWT Munsell Color Ksat#1 Ksat#2 Ksat#2
(feet below Notation
_ground surface)
Free Water 0-4' 4-6' 6-11'
Elevation 204' observed 11' 2.5Y 7/1 Loamy Sand/ Clay- Sandy Loam
bgs(Elevation Sandy Loam Expansive Saprolite
193') 10"/hour Not with mottles
Measured Not
Measured

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 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,
Scott Cole �\ +y... / co,,
North Carolina Licensed Soil Scientist d# �0 t
r Cr'

�gR / �� V��CC
�� co �I �� ,a?�vA LP
___________------- ?___:___----V _ , , :t1 .: •-4i ,, ,i. . ztt,, tutAto/1
tO
. - 6::','11(' . `.4.7171111y71.7744allAkk4.17#1
------------- -----___ _---- __.----s-- Nikk-110ihh„.
-_______-- •N_
ry------_______-- .401k-4,-- —'NN‘ ---- kso\V .•--0.111.1111"w '------ „,, _ \S. 411,4111VZ
, ' -. '4.1qfit
,— \ ‘‘,,,N._ i
71111, \ \ ... 4
lo0 Milik \1/4,,Ni:‘ ..* 444i,i&xXX in =Z -
p \t;1/4,, ,...\\,---,,,,-....-. , ,, ,,,,\"‘,\, _,...,,, ,16.:„..." N___.7- .-10,
c.,
\......
..
..
,...)
e.
�``` , NN\N-- Op' a
WmJ�oy:
: ilkel
\ a isi
it
el
6 \ m Y Y Y r
1\ _., ---------
4 i'it,' „) ,\ _____
N _
v..-z'
p ` 3 \ 234
,r ` `\\ ____
__________
to �z
M tD
O.
♦, ``�```` 8£Z
C e ``10
``♦`/ on
et
M ` ``I
__,
.:,
M p . .� ` p '
.,:::*
c...,
it? tip: c)--
et (NI M V
� , et
4::::
coco
p �� p et
Irsisor, M cOo +f IN
"ftp44.
/ o� p Fpp� �p 4 O
—� �------ boo,- .e...
` N
cn
to Ikp p co
e
et tl : / ut r F
o et
p / et �� —
�— co et p _ _
e� N
_i_ . .
ej o M 9 0 . r
(,.
1I2
cCO
O h r c:o to
et et et
et Q

I1 .. .-�t� \_ 1V/", \I" _. -:^ 'f-'1_Ili"_/,-/^^ - j- li _
``y` "-1.---, \----- ----- —:=r-r':-s/1(''1.-ram �-\ `-' i''r.k I
!t __ _ __ ———.r.-4.T -tom./--1- _,-- \_ \ ( \
11.'2' •r: 7 -r J r r_-f\ r r" , , \--\rf='=q.-=_L_k_.....'..---- G,--"i
,,
), /
Li-‘I--:__4 4..._,—_-) ..!---,-?r---r bra\ -=e- —— _✓ / 1\I '
^ a
l`
,4, .\
▪ j~__ -\, \`\..\ _ _ ---- \� /' / / / ' __ `I- . --.-_ \
\r;...--- �h - -\._-_- - --• '- /` /1 J/ I / / / / f ♦ `� `:\ '��`�`. --
\/ — — __— —^ -, v . / . / \-// / / / /i 1-'-,_—\ - - -N-N_ __ �---�
l /-"`_ _' \- ! _--\� '\ I ' I - r r'' ,' /r /, /\ / ♦i' '------ \ '" :\C,\_-
--..--\---''''
� ---'--'\,-_.--_ `'--- -----' �\ _iJ'c' - C/ I' •' / `\ i �° ( IN / / /_`.\--——_'\-'`\
sj
— � ---"i / I `:' '.;_- ----- `\`
---- r - _ ' / / - r\ 1 I /i I �w. .,:\\
- /---` _ '---- _`-1.- - _ ' • ---- .V ' I �``/ ( L/ I it \I ^- `\ /--
/ I. .(' ' • 1 •,-. '\ �' \\•/ — �L
lam' - -.'' -- '-� .i ._\ \� - -
\ t .,/ it _C// ,I' J i v ,. /\a \`A i \ \`` \ \ ^/' - -- 1.>
'- ._/-' - .. —\- --.\/```-` -.._` ""7 i C__i /_ . I 1 ♦ 1 \ \ \\ \-� _�i--`-
J i \ S v /' i I 1 \ `\ , , .�_ ----,
,, r- 1 i-' \ 1 i , \ \ \ , w\ /
• / -_ /:---,-/-
-_ _ __ /� - \_/ _ _:I- / °v 1\, '\\`\`\` J//i
\ _I/__' \� __ `---/ \r ` _' ..7,l/^_ _-___ / / ♦ I y \ \\\\\\\I\`r\\\( _
/ ' ^.l 7/ , S' C C .. `Cl - 1 \_' __�\l- i I \\ 1 \\Y'1\\\ 1
/' __-- �,C "/f ,._ ' _ ^\1.' `---_ /-"-------'\"''
- i / \ \ \ k\�\\\\\ I y
./ , _I I /. , /,,\ Si I `_I __ -- `\ �- '-/ / `` `\\\\\\1\\\\\I\
-
-/.' 4 /I \\ \ I-/ri,.- p,\.:+'\_-\ ✓;-. (_1 1-/'+�/-- — \: \ \\-'- /""------.♦ 9.' i 1\\j\\\\\\.
-y • /
- �L 1-" _ , / I- .\ \\ .- • - ,/•�_ -/1�
r-
1-- 1` -.I , / / / / ,/\ • - < `^ - ?v - - _/ /C/ -__ .\ \\ i- i.-_ l
` \1 i/ ; I i',F- `, \ S'i--,- 1 - / - ` `
�J/`-\ i i 1 I /' _ • \ ` ♦ _ ' i/ i/ r"\\ N', ,, :-..,---,',...\ram`�-
I / / /�_`- 'i-\ __ `- __''//'i/r `�i. r
I .G ) - `-✓
-_-_. _▪ - ,,,._\,-,-__:,--:--,--- -/ / � r'// ' r 1 ` \ \ _ _1 - /�/ - :-'/�-Is'$'=�'-.,__--`.`. .-$� _
':�`,: \-- --/// D /l //:./ "e\\\ ` -\/ --1,,,,--/'---i /// �'- -'�-`\. -_ -' ,
`'C \\``:`.� —1....----_,--'m //%/'� -\ I _ -\ �--/-; --,/-_/!_ - -J _�
; ` . \---- _D V/Ji/'//_. 1 'I ./.__` I / - /,--i j/� --- --- 41.—�./f _- -
/ mSom\ \ - - - -_� --_'-/ -- __
\L\ -\��-^-> i j,_ 5 \ ---'`_ 4�'.�'/- r—/ ' - -_-
--IC `._\\C _ _II i'/ --11`- -_''\ ----_/'J '-_C--_'_- -/—/ ;.'"' l^ '/_-` �_
I� -`,� _-_ -2 '/iy \ tom'-_-'i7 —/ - ' /�- _ 1 C `_. � � /---,Lei" I� `
Ili .\S' -> \• 1 -'_-- %- *= r r'o` I __ . --`\-
5
./III\\\\-___ -y ___ • �• _- _, / :-.' • --, 'b"l" —S\.� - \ i• ��I
II11 \\,/ - _ N-,` '/-o•-•-/,„ -C _ r. r-. IL / \ �1
1 \\, \"��^ - i'` - ^/ /'r/C' `_-- - .,-1\ -.,,• _- `-. \J- I Imo- 1`r \ `. 1
_III\\\_'_---- - �` - ----'i/I( ' j/'.v_s, Q,` -- _\--'_ -/ - i I` i �" \
y /- ( .1
1i1\`� '\�_```�ecr\iL\`��n %'i ii \\\ r- \- \�i �..I \,`,—,.i\./�_/-,r U I�' \) `\ `1_
i- _I r� I� .� -_ -`-- - --��_i / \ /i-\/-y/�^ ten_- V _ _/ I/ 5 W.. `\
_1
pll E a V g Io i := PRE-DEVELOPED DRAINAGE AREA MAP BARRETT q`m.
s= a; . yI LANCASTER ���� Bowman
D �s "gy m p z on�s�;slss�s,o
v$ ,2
,,,, N PARKER CHURCH RD,RAEFORD,HOKE COUNTY,NC .m m
2 eo.me�rvonn c„oim,ua.

�
\_ 1 �J
1 I 1� !1 —1 i _ .. I
9 "I ' ,) f- _yam_ rf1 —_(;es —_---- J "- 1 I/—
--
/ _-_` .\ CF 7 /-- / ./. i f t -._ L \\—;\ \ --- ----"^r
___
a
i �, — % r----- -,„-/_,_ \ID 17 �'3_ / / / L ,./; ,,- \\ —^_r\\ , Z--- `````\_ __--
ill,
_ J / )/\ r- \ � , i ei�, I ` \mil\— . — . —_—_— "`—'
_ss
ity
_`i\ _�= '-- /,--,
r_ L, \\ r ;',. \, -1/4 .-', -fir r ,— --�� -\``- -Z / - ;-{ ,,, - /, - _ I`— -I -` -0 'i' \`\ --- --.�e,'.�/ k' a j "< -- . / , 7 L _-,,;, \I \ -. J
I I i,�, \`` __ n_^ -i ` ` ,\--- i i' - .- __tit` - � . , ,"^ A
�._ - J/^\ ^ /1 ./ ( it N\\ \\�—
�-- -A •^ `__•—'/a✓ — =�_'_�` \�`� \ wM' , <,/' ,\ \\`\, ' ,\I
R
-Y
--�
- _ ; A m POST-DEVELOPED DRAINAGE AREA MAP am ma Now o q`a
N s4= g LCASR oh Bowman
T ; p 2 Phone Is,slssa-as�o
4$ q N PARKER CHURCH RD,RAEFORD,HOKE COUNTY,NC m
m 8 eo.marvonn carow,ue

Bowman
NORTH CAROLINA
APPENDIX B
Wet Pond Calculations
Design Supplement
CN Values
Time of Concentration Calculations
Infiltration Basin Design
Hydrograph
Stormwater Management Details
Spillway Design
Lancaster -Storm water Design Report 8

SUPPLEMENT-EZ COVER PAGE
FORMS LOADED
PROJECT INFORMATION
1 Project Name Lancaster
2 Project Area(ac) 10.82
3 Coastal Wetland Area(ac) -
4 Surface Water Area(ac) -
5 Is this project High or Low Density? High
6 Does this project use an off-site SCM? No
COMPLIANCE WITH 02H.1003(4)
7 Width of vegetated setbacks provided(feet) 30 _
8 Will the vegetated setback remain vegetated? Yes
9 If BUA is proposed in the setback,does it meet NCAC 02H.1003(4)(c-d)? N/A
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 Bayfilter 0
26 Filterra 0
i.
FORMS LOADED
7DESIGNER CERTIFICATION
27 Name and Title: _ Carlo Pardo, PE
28 Organization: Bowman North Carolina,Ltd.
29 Street address: 4006 Barrett Drive,Suite 104
30 City,State,Zip: Raleigh,NC 27609
31 'Phone number(s): 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.
Designer \`,��tttillil:;ii;;/yy,
ii
SEAL
r
:,1---
Signatur f Designer
051571
i '•• t'
��///nimillttt���� 1) 17inti
Seal Dale

DRAINAGE AREAS
1 r0 Is this a high density project? I Yes
2 If so,number of drainage areas/SCMs 1
3 Does this project have low density areas? No
4 If so,number of low density drainage areas
Is all/part of this project subject to previous rule
5 ;versions? No
FORMS LOADED
DRAINAGE AREA INFORMATION Entire Site 1 1 —'1
[ —
4 Type of SCM - ' Infiltration Basin
5 Total drainage area(sq ft) 471494 sf 393707
6 Onsite drainage area(sq ft) 471494 sf 386138
7 Offsite drainage area(sq ft) 7569
8 Total BUA in project(sq ft) 100880 sf 108449 sf
New BUA on subdivided lots(subject to permitting)
9 ,(sq ft) 64000 sf 64000 sf
New BUA not on subdivided lots(subject to
10 ,permitting)(sf) 36880 sf 36880 sf _
11 Offsite BUA(sq ft) 7569 sf
12 Breakdown of new BUA not on subdivided lots:
-Parking(sq ft) _
-Sidewalk(sq ft) 5026 sf 5026 sf
-Roof(sq ft)
-Roadway(sq ft) 31854 sf 31854 sf
-Future(sq ft) __
-Other,please specify in the comment box
below ss ft)
New infiltrating permeable pavement on
' 13 'subdivided lots(sq ft)
New infiltrating permeable pavement not on
14 subdivided lots(sq ft)
Existing BUA that will remain(not subject to
15 permitting)(sq�
16 Existing BUA that is already permitted(sq ft) _
17 Existing BUA that will be removed(sq ft) 4117 sf 4117 sf
18 Percent BUA 21.40% 27.5%
19 Design storm(inches) 1.0 in
20 Design volume of SCM(Cu ft) 36158 cf
21 Calculation method for design volume Simple Method
•ADDITIONAL INFORMATION
Please use this space to provide any additional information about the
22 drainage area(s):
Line 11-The 7,569 sf of off-site impervious is made up of ROW and neighboring parcels that were assumed
100%BUA.
In the pond calculations the pre-developed drainage area has 11,240 sf(0.26 ac.)of BUA.The 4,117 sf listed
above is the existing,on-site BUA.The remaining 7,123 sf of BUA is off-site,and is either included in Line 11,
or will not drain to the infiltration basin after development.

INFILTRATION SYSTEM
1 ;Drainage area number I 1
2 Minimum required treatment volume(cu ft) 9774 cf
GENERAL MDC FROM 02H.1050
3 Is the SCM sized to treat the SW from all surfaces at build-out? Yes
4 'Is the SCM located away from contaminated soils? Yes
5 What are the side slopes of the SCM(H:V or enter"Vertical'for
trenches)? 3:1
6 Does the SCM have retaining walls,gabion walls or other engineered
4side slopes? No
7 'Are the inlets,outlets,and receiving stream protected from erosion
(10-year 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? I Pump(preferred)
10 If applicable,will the SCM be cleaned out after construction? Yes
11 Does the maintenance access comply with General MDC(8)? - j Yes
12 Does the drainage easement comply with General MDC(9)? Yes
13 If the SCM is on a single family lot,does(will?)the plat comply with
General MDC 10)? N/A
14 Is there an O&M Agreement that complies with General MDC(11)? Yes_
15 Is there an O&M Plan that complies with General MDC(12)? Yes
16 .Does the SCM follow the device specific MDC? Yes
17 Was the SCM designed by an NC licensed professional? Yes
"INFILTRATION SYSTEM MDC FROM 02H.1051
18 Proposed slope of the subgrade surface(%) 0%
19 Are terraces or baffles provided? No
20 Type of pretreatment: Fore_bay
Soils Data
21 Was the soil investigated in the footprint and at the elevation of the
infiltration system? Yes
22 SHWT elevation(fmsl) 193.00
23 Depth to SHWT per soils report(in) 132.00
24 Ground elevation at boring in soils report(fmsl) 204.00
25 Is a detailed hydrogeologic study attached if the separation is
between 1 and 2 feet? N/A
26 Soil infiltration rate(in/hr) 4 5.00
27 Factor of safety(FS) (2 is recommended): j 2.00
Elevations
29 Bottom elevation(fmsl) ( 200 ft
30 Storage elevation(fmsl) 201.7 ft
31 Bypass elevation(fmsl) 201.7 ft
For Basins Only
32 Bottom surface area(ft2) 19800 ft
33 Storage elevation surface area(ft2) 22760.ft
For Trenches Only
34 Length(ft)
35 Width(ft)
36 'Perforated pipe diameter,if applicable(inches) _
37 Number of laterals
38 Total length of perforated piping
39 Stone type,if applicable
40 Stone porosity(%)
41 Is stone free of fines?
42 Is the stone wrapped in geotextile fabric?
43 Has at least one inspection port been provided?
I Volumes/Drawdown
L 44 Design volume of SCM(cu ft) 36158 cf
45 Time to draw down(hours) 18.9 hrs
ADDITIONAL INFORMATION
46 'Please use this space to provide any additional information about the
infiltration system(s):
Line 26-The soils report found the infiltration rate of the soil for DA 1 to be 10.0"/hr.A
=more conservative value of 5.0"/hr was used in the calculations,to account for
clogging of the soils that will happen over time.
Infiltration 1 4:21 PM 1/17/2024

Bowman North Carolina, Ltd.
Lancaster, Hoke County, NC
Curve Number Calculation (CN)
Pre-Developed Conditions(Wet Pond)
Drainage Area(acres): 9.55
Existing Soil Groups:
Soil Group Map Symbol Soil Description Acres Percent of DA
A WaB/NoB Candor Sand 7.03 74%
C BaD/BaB Blaney,Gilead,Vaucluse loamy sand 2.52 26%
Existing Land Uses:
Land Use Description Existing Soil Group Acres Curve# Weighted CN
Open Space-Good Stand A 1.66 45 7.8
Wooded -Thin Stand A 1.05 50 5.5
Wooded -Good Stand A 3.67 60 23.0
Wooded -Good Stand C 2.52 70 18.5
Road - Dirt A 0.39 72 2.9
Impervous Area A/C 0.26 98 2.6
Cumulative Curve#= 60.4

Bowman North Carolina, Ltd.
Lancaster, Hoke County, NC
Curve Number Calculation (CN)
Post-Developed Conditions (Wet Pond)
Drainage Area(acres): 9.04
Existing Soil Groups:
Soil Group Map Symbol Soil Description Acres Percent of DA
A CaB Candor Sand 5.88 65%
C BaB/BaD/GdB/VaD Blaney,Gilead,Vaucluse loamy sand 3.16 35%
Existing Land Uses:
Land Use Description Existing Soil Group Acres Curve # Weighted CN
Open Space - Good Condition A 3.94 55 24.0
Open Space - Good Condition C 2.61 77 22.3
Impervious Area 2.49 98 27.0
Cumulative Curve# = 73.2

TIME OF CONCENTRATION
Existing Conditions DA
SCS Methodology
OPEN CHANNEL
SHALLOW CONC FLOW: FLOW: TOTAL
SHEET FLOW: SEGMENT 1 SEGMENT 1
Manning's Equation:
Tc=(0.007(nL)"0.8)/(P2^0.5)(s^0.4) 2-year/24-hr Tc=L/60'V V=1.49R'S'°/n
Basin Comments Length Elev1 Elev2 Slope Rainfall Depth Manning's Ts, Length Elev2 Elev3 Slope Condition Vavg Ts, Cross Sectional Wetted Perimeter Hydraulic Radius Length Elev3 Elev4 Slope Manning's V Tcp ToTOToL Tc(minimum) Tlag Basin
(ft (ft/ft) TP-40(in) "n" (min) (ft) (ft/ft) TR-55 Fig.3-1 (ft/sec) (min) Flow Area(ft"2) (ft) (ft) (ft) (fUft) "n" (fps) (min) (min) (10 min) 0.6*Tc(hrs)
1 100 253.0 251.9 0.011 3.68 0.24 16.90 1163 251.9 193 0.05064 Unpaved 3.60 5.38 22.29 22.29 0.22 1
9/5/20234:57 PM G:\HYDRO\projects\TIMECONC(Lancaeterl.Ne

Infiltration Basin Design
Site Information
Sub Area Location: Drainage To Infiltration Basin #1
Drainage Area (DA) = 9.04 Acres 393,707 sf
Impervious Area (IA) = 2.49 Acres 108,449 sf
Percent Impervious (I) = 27.5 %
Required Water Quality Volume
Design Storm = 1 inch
Determine Rv Value = 0.05 + .009 (I) = 0.30 in/in
Water Quality Volume = 0.224 ac-ft
Water Quality Volume = 9,774 cf
Water Quality Volume = 0.298 inches of runoff
NOAA 1-year, 24-hour event = 3.08 inches
Minimum Surface Area
SA= (12*FS*DV)/(K*T)
Factor of Safety (FS) = 2
Design Volume (DV) = 36,158 cf
Hydraulic Conductivity of Soil = 5.00 in/hr
Max Dewatering Time = 72 hours
SA= 2410.5 sf
Drawdown Time
T= FS * (DV*12)/(K*SA)
Factor of Safety (FS) = 2
Design Volume (DV) = 36,158 cf
Hydraulic Conductivity of Soil = 5.00 in/hr
Surface Area Provided = 19,800 sf
Drawdown Time = 8.8 hours

1
Hydrograph Summary Report Hydraflow Hydrographs Extension for Autodesk®Civil 3D®by Autodesk, Inc.v2022
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 2.112 2 730 12,728 SCM Pre-Developed
2 SCS Runoff 13.62 2 718 27,449 SCM Post-Developed
3 Reservoir 0.000 2 740 0 2 200.51 10,579 Post Through SCM
5 SCS Runoff 0.092 2 360 634 1.0 Post-Developed to SCM
6 Reservoir 0.012 2 362 131 5 200.02 367 1.0inPost Through SCM
Infiltration #1.gpw Return Period: 1 Year Monday, 09/ 18/2023

2
Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk®Civil 3D®by Autodesk, Inc.v2022 Monday,09/18/2023
Hyd. No. 1
SCM Pre-Developed
Hydrograph type = SCS Runoff Peak discharge = 2.112 cfs
Storm frequency = 1 yrs Time to peak = 730 min
Time interval = 2 min Hyd. volume = 12,728 cuft
Drainage area = 9.550 ac Curve number = 60.4
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = User Time of conc. (Tc) = 22.30 min
Total precip. = 3.04 in Distribution = Type II
Storm duration = 24 hrs Shape factor = 484
SCM Pre-Developed
Q (cfs) Hyd. No. 1 -- 1 Year Q (cfs)
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. 1 Time (min)

3
Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk®Civil 3D®by Autodesk, Inc.v2022 Monday,09/18/2023
Hyd. No. 2
SCM Post-Developed
Hydrograph type = SCS Runoff Peak discharge = 13.62 cfs
Storm frequency = 1 yrs Time to peak = 718 min
Time interval = 2 min Hyd. volume = 27,449 cuft
Drainage area = 9.040 ac Curve number = 73.2
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = User Time of conc. (Tc) = 5.00 min
Total precip. = 3.04 in Distribution = Type II
Storm duration = 24 hrs Shape factor = 484
SCM Post-Developed
Q (cfs) Hyd. No. 2 -- 1 Year Q (cfs)
14.00 I 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
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Hyd No. 2 Time (min)

4
Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk®Civil 3D®by Autodesk, Inc.v2022 Monday,09/18/2023
Hyd. No. 3
Post Through SCM
Hydrograph type = Reservoir Peak discharge = 0.000 cfs
Storm frequency = 1 yrs Time to peak = 740 min
Time interval = 2 min Hyd. volume = 0 cuft
Inflow hyd. No. = 2 - SCM Post-Developed Max. Elevation = 200.51 ft
Reservoir name = BMP Pond Max. Storage = 10,579 cuft
Storage Indication method used. Exfiltration extracted from Outflow.
Post Through SCM
Q (cfs) Hyd. No. 3 -- 1 Year Q (cfs)
14.00 1 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
Time (min)
Hyd No. 3 Hyd No. 2 111111111 Total storage used = 10,579 cuft

5
Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk®Civil 3D®by Autodesk, Inc.v2022 Monday,09/18/2023
Hyd. No. 5
1.0 Post-Developed to SCM
Hydrograph type = SCS Runoff Peak discharge = 0.092 cfs
Storm frequency = 1 yrs Time to peak = 360 min
Time interval = 2 min Hyd. volume = 634 cuft
Drainage area = 11.260 ac Curve number = 72.9
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = User Time of conc. (Tc) = 5.00 min
Total precip. = 1.00 in Distribution = SCS 6-Hr
Storm duration = 6.00 hrs Shape factor = 484
1.0 Post-Developed to SCM
Q (cfs) Hyd. No. 5 -- 1 Year Q (cfs)
0.10 0.10
0.09 0.09
0.08 [ 0.08
_ 7//
0.07 [ 0.07
0.06 1 0.06
0.05 0.05
0.04 0.04
0.031 0.03
4
0.02 0.02
0.01 0.01
0.00 - ,- 0.00
0 60 120 180 240 300 360 420
Hyd No. 5 Time (min)

6
Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk®Civil 3D®by Autodesk, Inc.v2022 Monday,09/18/2023
Hyd. No. 6
1.0inPost Through SCM
Hydrograph type = Reservoir Peak discharge = 0.012 cfs
Storm frequency = 1 yrs Time to peak = 362 min
Time interval = 2 min Hyd. volume = 131 cuft
Inflow hyd. No. = 5 - 1.0 Post-Developed to SCIA/lax. Elevation = 200.02 ft
Reservoir name = BMP Pond Max. Storage = 367 cuft
Storage Indication method used. Exfiltration extracted from Outflow.
1.0inPost Through SCM
Q (cfs) Hyd. No. 6 -- 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 h 0.02
111 1 II 1
11 1 11 11 1
0.01 1 1 0.01
0.00 — — 0.00
0 120 240 360 480 600 720 840
Time (min)
Hyd No. 6 Hyd No. 5 111111111 Total storage used = 367 cuft

7
Hydrograph Summary Report Hydraflow Hydrographs Extension for Autodesk®Civil 3D®by Autodesk, Inc.v2022
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 4.736 2 730 22,183 SCM Pre-Developed
2 SCS Runoff 20.22 2 718 40,448 SCM Post-Developed
3 Reservoir 0.000 2 724 0 2 200.80 16,547 Post Through SCM
5 SCS Runoff 0.000 2 n/a 0 1.0 Post-Developed to SCM
6 Reservoir 0.000 2 n/a 0 5 200.00 0.000 1.0inPost Through SCM
Infiltration #1.gpw Return Period: 2 Year Monday, 09/ 18/2023

8
Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk®Civil 3D®by Autodesk, Inc.v2022 Monday,09/18/2023
Hyd. No. 1
SCM Pre-Developed
Hydrograph type = SCS Runoff Peak discharge = 4.736 cfs
Storm frequency = 2 yrs Time to peak = 730 min
Time interval = 2 min Hyd. volume = 22,183 cuft
Drainage area = 9.550 ac Curve number = 60.4
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = User Time of conc. (Tc) = 22.30 min
Total precip. = 3.68 in Distribution = Type II
Storm duration = 24 hrs Shape factor = 484
SCM Pre-Developed
Q (cfs) Hyd. No. 1 -- 2 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. 1 Time (min)

9
Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk®Civil 3D®by Autodesk, Inc.v2022 Monday,09/18/2023
Hyd. No. 2
SCM Post-Developed
Hydrograph type = SCS Runoff Peak discharge = 20.22 cfs
Storm frequency = 2 yrs Time to peak = 718 min
Time interval = 2 min Hyd. volume = 40,448 cuft
Drainage area = 9.040 ac Curve number = 73.2
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = User Time of conc. (Tc) = 5.00 min
Total precip. = 3.68 in Distribution = Type II
Storm duration = 24 hrs Shape factor = 484
SCM Post-Developed
Q (cfs) Hyd. No. 2 -- 2 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 1320 1440 1560
Hyd No. 2 Time (min)

10
Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk®Civil 3D®by Autodesk, Inc.v2022 Monday,09/18/2023
Hyd. No. 3
Post Through SCM
Hydrograph type = Reservoir Peak discharge = 0.000 cfs
Storm frequency = 2 yrs Time to peak = 724 min
Time interval = 2 min Hyd. volume = 0 cuft
Inflow hyd. No. = 2 - SCM Post-Developed Max. Elevation = 200.80 ft
Reservoir name = BMP Pond Max. Storage = 16,547 cuft
Storage Indication method used. Exfiltration extracted from Outflow.
Post Through SCM
Q (cfs) Hyd. No. 3 -- 2 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
0 240 480 720 960 1200 1440 1680 1920
Time (min)
Hyd No. 3 Hyd No. 2 111111111 Total storage used = 16,547 cuft

11
Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk®Civil 3D®by Autodesk, Inc.v2022 Monday,09/18/2023
Hyd. No. 5
1.0 Post-Developed to SCM
Hydrograph type = SCS Runoff Peak discharge = 0.000 cfs
Storm frequency = 2 yrs Time to peak = n/a
Time interval = 2 min Hyd. volume = 0 cuft
Drainage area = 11.260 ac Curve number = 72.9
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = User Time of conc. (Tc) = 5.00 min
Total precip. = 0.00 in Distribution = SCS 6-Hr
Storm duration = 6.00 hrs Shape factor = 484
1.0 Post-Developed to SCM
Q (cfs) Hyd. No. 5 -- 2 Year Q (cfs)
0.10 0.10
0.09 I 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 20 40 60 80 100 120
Hyd No. 5 Time (min)

12
Hydrograp i Report
Hydraflow Hydrographs Extension for Autodesk®Civil 3D®by Autodesk, Inc.v2022 Monday,09/18/2023
Hyd. No. 6
1.0inPost Throug i SCM
Hydrograph type = Reservoir Peak discharge = 0.000 cfs
Storm frequency = 2 yrs Time to peak = n/a
Time interval = 2 min Hyd. volume = 0 cuft
Inflow hyd. No. = 5 - 1.0 Post-Developed to SCIA/lax. Elevation = 200.00 ft
Reservoir name = BMP Pond Max. Storage = 0 cuft
Storage Indication methoc used. Exfiltration racted from Outflow.
1.0inPost Through SCM
Q (cfs) Hyd. No. 6 -- 2 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
0 600 1200 1800 2400 3000 3600 4200 4800 5400 6000
Time (min)
Hyd No. 6 Hyd No. 5 111111111 Total storage used = 0 cuft

13
Hydrograph Summary Report Hydraflow Hydrographs Extension for Autodesk®Civil 3D®by Autodesk, Inc.v2022
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 15.12 2 728 56,513 SCM Pre-Developed
2 SCS Runoff 40.47 2 716 81,720 SCM Post-Developed
3 Reservoir 1.315 2 746 2,481 2 201.77 37,824 Post Through SCM
5 SCS Runoff 0.000 2 n/a 0 1.0 Post-Developed to SCM
6 Reservoir 0.000 2 n/a 0 5 200.00 0.000 1.0inPost Through SCM
Infiltration #1.gpw Return Period: 10 Year Monday, 09/ 18/2023

14
Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk®Civil 3D®by Autodesk, Inc.v2022 Monday,09/18/2023
Hyd. No. 1
SCM Pre-Developed
Hydrograph type = SCS Runoff Peak discharge = 15.12 cfs
Storm frequency = 10 yrs Time to peak = 728 min
Time interval = 2 min Hyd. volume = 56,513 cuft
Drainage area = 9.550 ac Curve number = 60.4
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = User Time of conc. (Tc) = 22.30 min
Total precip. = 5.45 in Distribution = Type II
Storm duration = 24 hrs Shape factor = 484
SCM Pre-Developed
Q (cfs) Hyd. No. 1 -- 10 Year Q (cfs)
18.00 - 18.00
15.00 1 15.00
12.00 12.00
9.00 9.00
6.00 6.00
3.00 3.00
0.00 I •
0.00
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Hyd No. 1 Time (min)

15
Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk®Civil 3D®by Autodesk, Inc.v2022 Monday,09/18/2023
Hyd. No. 2
SCM Post-Developed
Hydrograph type = SCS Runoff Peak discharge = 40.47 cfs
Storm frequency = 10 yrs Time to peak = 716 min
Time interval = 2 min Hyd. volume = 81,720 cuft
Drainage area = 9.040 ac Curve number = 73.2
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = User Time of conc. (Tc) = 5.00 min
Total precip. = 5.45 in Distribution = Type II
Storm duration = 24 hrs Shape factor = 484
SCM Post-Developed
Q (cfs) Hyd. No. 2 -- 10 Year Q (cfs)
50.00 50.00
•
40.00 40.00
30.00 1 30.00
20.00 20.00
10.00 I 10.00
0.00 - • '- 0.00
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Hyd No. 2 Time (min)

16
Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk®Civil 3D®by Autodesk, Inc.v2022 Monday,09/18/2023
Hyd. No. 3
Post Through SCM
Hydrograph type = Reservoir Peak discharge = 1.315 cfs
Storm frequency = 10 yrs Time to peak = 746 min
Time interval = 2 min Hyd. volume = 2,481 cuft
Inflow hyd. No. = 2 - SCM Post-Developed Max. Elevation = 201.77 ft
Reservoir name = BMP Pond Max. Storage = 37,824 cuft
Storage Indication method used. Exfiltration extracted from Outflow.
Post Through SCM
Q (cfs) Hyd. No. 3 -- 10 Year Q (cfs)
50.00 50.00
40.00 40.00
30.00 30.00
20.00 20.00
10.00 10.00
111
��uuullll
0.00 - 0.00
0 120 240 360 480 600 720 840
Time (min)
Hyd No. 3 Hyd No. 2 111111111 Total storage used = 37,824 cuft

17
Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk®Civil 3D®by Autodesk, Inc.v2022 Monday,09/18/2023
Hyd. No. 5
1.0 Post-Developed to SCM
Hydrograph type = SCS Runoff Peak discharge = 0.000 cfs
Storm frequency = 10 yrs Time to peak = n/a
Time interval = 2 min Hyd. volume = 0 cuft
Drainage area = 11.260 ac Curve number = 72.9
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = User Time of conc. (Tc) = 5.00 min
Total precip. = 0.00 in Distribution = SCS 6-Hr
Storm duration = 6.00 hrs Shape factor = 484
1.0 Post-Developed to SCM
Q (cfs) Hyd. No. 5 -- 10 Year Q (cfs)
0.10 0.10
0.09 I 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 20 40 60 80 100 120
Hyd No. 5 Time (min)

18
Hydrograph Report
Hydraflow Hydrographs E xtension for Autodes4®Civil 3D®by Autodesk, Inc.v2022 Monday,09/18/2023
Hyd. No. 6
1.0inPost Throuc h SCM
Hydrograph type = Re;ervoir Peak discharge = 0.000 cfs
Storm frequency = 10 yrs Time to peak = n/a
Time interval = 2 min Hyd. volume = 0 cuft
Inflow hyd. No. = 5 - 1.0 Post-Developed to SCIA/lax. Elevation = 200.00 ft
Reservoir name = BM' Pond Max. Storage = 0 cuft
Storage Indication method used. Exfiltration exfacted from Outflow.
1.0inPost Through SCM
Q (cfs) Hyd. No. 6 -- 10 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 — I 0.02
0.01 0.01
0.00 - 0.00
0 600 1200 1800 2400 3000 3600 4200 4800 5400 6000
Time (min)
Hyd No. 6 Hyd No. 5 111111111 Total storage used = 0 cuft

19
Hydrograph Summary Report Hydraflow Hydrographs Extension for Autodesk®Civil 3D®by Autodesk, Inc.v2022
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 36.22 2 728 127,237 SCM Pre-Developed
2 SCS Runoff 76.68 2 716 156,907 SCM Post-Developed
3 Reservoir 46.12 2 720 52,044 2 202.48 54,752 Post Through SCM
5 SCS Runoff 0.000 2 n/a 0 1.0 Post-Developed to SCM
6 Reservoir 0.000 2 n/a 0 5 200.00 0.000 1.0inPost Through SCM
Infiltration #1.gpw Return Period: 100 Year Monday, 09/ 18/2023

20
Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk®Civil 3D®by Autodesk, Inc.v2022 Monday, 09/18/2023
Hyd. No. 1
SCM Pre-Developed
Hydrograph type = SCS Runoff Peak discharge = 36.22 cfs
Storm frequency = 100 yrs Time to peak = 728 min
Time interval = 2 min Hyd. volume = 127,237 cuft
Drainage area = 9.550 ac Curve number = 60.4
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = User Time of conc. (Tc) = 22.30 min
Total precip. = 8.30 in Distribution = Type II
Storm duration = 24 hrs Shape factor = 484
SCM Pre-Developed
Q (cfs) Hyd. No. 1 -- 100 Year Q (cfs)
40.00 40.00
I
30.00 30.00
20.00 20.00
10.00 10.00
0.00 —L ...-
i - 0.00
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Time (min)
— Hyd No. 1

21
Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk®Civil 3D®by Autodesk, Inc.v2022 Monday,09/18/2023
Hyd. No. 2
SCM Post-Developed
Hydrograph type = SCS Runoff Peak discharge = 76.68 cfs
Storm frequency = 100 yrs Time to peak = 716 min
Time interval = 2 min Hyd. volume = 156,907 cuft
Drainage area = 9.040 ac Curve number = 73.2
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = User Time of conc. (Tc) = 5.00 min
Total precip. = 8.30 in Distribution = Type II
Storm duration = 24 hrs Shape factor = 484
SCM Post-Developed
Q (cfs) Hyd. No. 2 -- 100 Year Q (cfs)
80.00 I 80.00
•
70.00 70.00
60.00 60.00
50.00 50.00
40.00 40.00
30.00 30.00
20.00 20.00
I
10.00 10.00
0.00 — 0.00
0 120 240 360 480 600 720 840 960 1080 1200 1320
Hyd No. 2 Time (min)

22
Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk®Civil 3D®by Autodesk, Inc.v2022 Monday,09/18/2023
Hyd. No. 3
Post Through SCM
Hydrograph type = Reservoir Peak discharge = 46.12 cfs
Storm frequency = 100 yrs Time to peak = 720 min
Time interval = 2 min Hyd. volume = 52,044 cuft
Inflow hyd. No. = 2 - SCM Post-Developed Max. Elevation = 202.48 ft
Reservoir name = BMP Pond Max. Storage = 54,752 cuft
Storage Indication method used. Exfiltration extracted from Outflow.
Post Through SCM
Q (cfs) Hyd. No. 3-- 100 Year Q (cfs)
80.00 80.00
70.00 70.00
60.00 60.00
50.00 50.00
40.00 40.00
30.00 30.00
20.00 20.00
10.00 10.00
0.00
0 120 240 360 480 600 720 840
Time (min)
Hyd No. 3 Hyd No. 2 111111111 Total storage used = 54,752 cuft

23
Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk®Civil 3D®by Autodesk, Inc.v2022 Monday,09/18/2023
Hyd. No. 5
1.0 Post-Developed to SCM
Hydrograph type = SCS Runoff Peak discharge = 0.000 cfs
Storm frequency = 100 yrs Time to peak = n/a
Time interval = 2 min Hyd. volume = 0 cuft
Drainage area = 11.260 ac Curve number = 72.9
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = User Time of conc. (Tc) = 5.00 min
Total precip. = 0.00 in Distribution = SCS 6-Hr
Storm duration = 6.00 hrs Shape factor = 484
1.0 Post-Developed to SCM
Q (cfs) Hyd. No. 5-- 100 Year Q (cfs)
0.10 0.10
0.09 I 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 20 40 60 80 100 120
Hyd No. 5 Time (min)

24
Hydrogra h Report
Hydraflow Hydrograph Extension for Autodeskt Civil 3D®by Autodesk, Inc.v2022 Monday,09/18/2023
Hyd. No. 6
1.0inPost Thro gh SCM
Hydrograph type = Res arvoir Peak discharge = 0.000 cfs
Storm frequency = 100 yrs Time to peak = n/a
Time interval = 2 mil Hyd. volume = 0 cuft
Inflow hyd. No. = 5 - 1.0 Post-Developed to SCIA/lax. Elevation = 200.00 ft
Reservoir nam ; = BMF' Pond Max. Storage = 0 cuft
Storage Indication me hod used. Exfiltration extr.cted from Outflow.
1.0inPost Through SCM
Q (cfs) Hyd. No. 6-- 100 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
0 600 1200 1800 2400 3000 3600 4200 4800 5400 6000
Time (min)
Hyd No. 6 Hyd No. 5 111111111 Total storage used = 0 cuft

1
I \
oY \ 1 \
/ / / \ \ \ice\ \ \ 1
/ / f / / / N� \ \ \ ��\ —\—_� \ \ I �\ --
/ / //
/ (/ // I �\ \ i��\ \ \ \ ( /
f / / \� \ I \ \ \ /" \ --(-- \` \ \
—0 \ \ j \ \ \ GRASS SPILLWAY /
\ \ \ \ REFER TO DETAIL
/ — \ /\ \ /1 \ \ , THIS SHEET I \\
\ \ \ \ �� \ ) \\ > I
y
N\ \ /\ / � \ \ \ I \ 1 \ r /
\,_^\ ` ' . (0\\ I I I I LA `� \ \ TOP OF l \ /
\ i' \ \ I 7 \ , , ,EMBANKMENT \ 1 II
\ \ lk\%/c( 1 I \ p \ ELEV=203.0�,� \\ \, 11 \ 1xo\ I\ \\ v `' I \ / /
\ 1 \
�i 1 \ \ I \\ o I \ I iJ ( )
\ STORMWATER 1 � - o ����'(��� ) \ �
MANAGEMENT • �>yP \ 1 \ I \ 1 \ \ /
1 EASEMENT \ \ c � �'�I� \ A V \ 1 A c N\
,\ ' \ (N \ 4 \) -, V AV A \ o \ � I 1
\ \ \ \ I \ / 1 \ \ \ \, 1 / , I � / /
\ . !: 1 / \ :�f 1 \I 1 I \ \\ \ \\ \\ O I \ // r / /
�\ k\ l� I \I I I\ST�QRM�VATER \TREATMENT \
\ > , 1 \ \\�N \ \ \ \ \\ I' 1 / '\\ / \\ //
\ J I` \I o�.\' \ \ \\ bP N\SPACEI I \ 1
I -\ \ \ \ \ \ P, 43 \S F� \ I I 1 I /
/ RIP RAP \ \ o� \ \ \ 1\ N\ \ \ \ \ \ \ \ I \ 1 6' \ / _/
\ DISSIPATER PAD \\ \\\ \ \ \ \ \ \ l \ \ \ \ \ \ I
\\ WIDTH=8' \ \ \ ) \ \ \ \ \ I rn 1
LENGTH=16' \\\ `\\\ \cc' \\ \\ \\ \ \ \ \\ \ \ \ \ \ \\ \\ I \
THICKNESS=24" \\ \ co •\ \ \ \ \ \ \ \ \ \ \ \ 1
RIP RAP CLASS=1 \\ \ c-� \ \ \ \ \ \ l \ \\ \ \ \ \ \ \. \I I /
I \ � \ \ \ \ \ ( \ \ \ II ) /
I \ \ o, \ \ \ I 1 i ( t \ 1 • 1
\ \ \\ \ ! c' \ \ \ \ \ 1 I 1 \ I 1 / / ^ -
` LOT I \ t\ `�' �o I \ \ \\ \ 1 I \ \ \�� f/ 1 , EMN
1 1 J
\\20,2421 SF ly \ 11 \ o \ 1 \\ I \ \ I 1 I '�
�1\\ \ / \\I \ �' I \.
I \ 1 !.'�II I \\ \r,
/ 00 �� 1 / \ \
III \\\ / `\/ \ \\�\ \ \ + / \)\ ,, \ \`\ 1 II 11 I I / \\�\
1 \ / ! \ \ 1 1 / / \
\ I \ / i 1 \\ I ( 1 I \� \ \ \ \ \ \ \
\\1 \�, / i I / -----____- --"\-- I (\ \1 \\ \\ \\ \\\\\\ \\\ \�\ \\
'( \\ I I ,I-- / / \ I l \ \\ \\ \\\ \ \\ \\ \
\ I 1 ( / I I I \ \\ \ \ \ \ \ \ \
l\\ (\\ J � � I 1 i I I ( \ I \ \ \ \ \\ \ \ � \
) \. 1, \,-7 ��� \ ,1 J l \ l \2 > \ \ N \ \ \ \
GRAPHIC SCALE
50 0 25 50 100 200
l!Im
PLAN VIEW
( IN FEET )
1 inch = 50 ft.
1 STORMWATER MANAGEMENT SYSTEM DETAILS
LLA NOT TO SCALE

RIP-RAP PRE-TREATMENT
FOREBAY AT PIPE INLETS
SEE DETAIL THIS SHEET
TOP OF EMBANKMENT=203.0
fr>NANNN, ` GRASS Sao ��
IW-YEAR STORM ELEVATION=202.48 M - ��� %>>>%/
10-YEAR STORM ELEVATION=201.77
SPILLWAY ELEVATION=201.7 /////�// A112FILTER FABRIC AT BOTTOM
AND SIDES aF CLEAN SAND
2-YEAR STORM ELEVATION=200.80 /' ////�/'lIMgj, Y 4 �/�
/�//�/%/%/%/%/*I ." 1'-0•CLEAN SAND �0��"��
I-YEAR STORM ELEVATION=200.51 '/' %//�//%% ZX T\N Wi\/\/ �A'
1.0•RAINFALL ELEVATION=200A2 �//j /�\��\. M , \�\�///�;���� //p
EXISTING GRADE=204.0 BOTTOM OF BASIN=200.0 a \�j -M M .� �//�� ��/��/��/��/��/\\�\
•
FILTER MIXTURE R co „//� • /
1'-0"OF CLEAN ASTM C-33 z,/ii i ��
SAND(MEDIUM AGGREGATE SAND 1 '��'�'������
WITH A SIZE RANGE OF 0.02-INCH cdi
TO 0.04-INCH DIAMETER) T �I=I I I_I _
23 LAYER OF GEOTEXTILE PERMEABLE
FILTER FABRIC(MIRAFI N-SERIES
FILTER FABRIC OR EQUIVALENT)
1'-0"MIN.UNDISTURBED IN-SITU g-
SOIL
2
• SEASONAL HIGH WATER TABLE=193.0
j>'11ta ,f e+t d.y,,
INFILTRATION BASIN TYPICAL SECTION
NTS

215 215
CI#11
210 _ EXISTING GRADE 21 0
FUTURE GRADE
TOP OF
EMBANKMENT
ELEV=203.0
\ GRASS SPILLWAY
ELEV=201.7
205 - \\ REF SHE
ET
THIS 205
\
62'-24" CLASS-III RCP ® 9.18%
200 200
BOTTOM OF INFILTRATION BASIN = 200.0
-0+50 0+00 1+00 2+00
I \FILTATIO\ 3ASI \ OFILE VIEW
HOIZO\ TAL SCALE: 1 "= 30'
VERTICAL SCALE: 1 "= 3'

C)
W N O O
0 0 o o r`1
w r
co Z rrn
C/7
(➢j-1 `L I- I--
co z D D W N o 0 0
CD
o o o o Z
m VD 0
�— v m
K� � -„,
'^
P1 I 0 = O
f—
➢ CO N 0 0 ND N.) N.) N O
Z o * cn CA NDO
-0 G7 P1 U) Ut W � NJ vl
p N m N CD O CD ➢ D
rn z m G
)
o➢ I n m
rn
.C)ao W O r—
c r) W m O cn
7➢ CA
^ Z z
N ' A C•7 NJ -, N 2) 23 D
z � rn Cn p ➢ m T
O N ID a) 0 C) M W
m
o w Co rn Fri z r
o X _ O O c=)
m
p Z CA = r r
TI O _
co r
-D Z O
✓z ➢
n_1 O CD -A w M 0 r
-<o O iv o m o
co rn cn OD O
CO cD 00 O
D
m
v
73 co
D
C/)
CO NN
W O �-- N -- � —1C') 0 —1 O c!) o -0 -0 = cc) C/) 212)
�^ D C,) (/') 00 CP I I p C 7D O TI _H 70 O 770 C 71 < (n
V, z Cn I m -< ' p-i C 3> D P1 D ZC O C'J 71 71 m 2:
z m 3> c/) rT1 z r- Cr) — Z P 1 D D )
r r 37D cD O� ZC C 000 � � ZW 73
r cn U) 77 cnc) ai c) = 71 mmmmN nz " cDi
z = c/) � CC CD CD Fri O DCcnZ
O 0 X O O Z7 .Z7 m n Fri Z cn O m Z O cn X ..
�m rrn * _ � m � � m Z � � mzND = C N .. ➢ D
0 or x * Z rT1 < r<T1mZ D � � C < m
m z S fZ 71 Z -1 -H < ff� ➢ rT1 MI
D I-O \ Z � � z OZ1 � � � (/)
CD C 7
r O Z D O -0 CA C71 OD C7 CO C D >
J z m Oz O C C 0 m D�
O G7 D2) 0 NO -< P1 1Ji
NJ
� 2] m m
Z 73 7D - Z O) 1 '�
m
oN c� —s � iN ivrncfl -H70 00 m
co co —I 61 � J � NO � O .ZI 0 = I
pm O N N Cn N W CD m Z c0
r- o q
mO () C) () C (-) Z CA�Z l ml Z 0 < J cn cn Cn
NJ
cn V) ND m m I- Cl)C o
O < O v
-II CA C m
n n O CD CI Z- O z Z
I-- CO v4, N -" 0 CD -A CO -H1 Z
z rr1 O) OO CA oC CDCC TI
➢ ic - co N N Co < N _ r
z O I
II z N N N N N C < D
m
0 N P1
�I o M 0 N O N COrn O
I— 0 CCOO J N 4, Z
DD D D D C/)
ND -< - -` 000 -H (') n (') CD
0 6' c; 000 = C mmMm -<
v I- NCnCCC 0 -1 U) UU) U)
rr1
< n n C-) C-) C-) C-) o
y NNP = P = < m
m M
O C
\ o
J

STORM DRAINAGE PIPE OR
CONCRETE FLUME
OUTFALL INTO POND LENGTH Sc WIDTH
DIMENSIR TOBE PER
RIP—RAP
P
.�__ =r .
APRON DETAIL
TAPER DEPTH
oo
FILTER BED ED ELEVATION
BIO—RETENTION N POND
II 111 11 iIII=ll 1-=I I .r P ° °
1-III III III III III II III—III-1S- FOREBAY 1 'gogo°o°o °o°o_ r.. \'II I1=of 4-=111= 2
1=1IMI11=111 , _00 •
I I I 1 I I I-
_1 \ ��1�-- 1-
—11I=11 fI11-1 I' •�—I H 11EI 11=1111
MII 111—I— —I11-111=1I I I1=1 -111=
III-rnElIIIET n-T-n n=11=1E=
—111-11 M 11E111-11 El I 1-111E11 M1 11-11
1=III IC I=I= Il III 1i1 0000
6" CLASS B o0
RIP—RAP OVER
RIP-RAP FOREBAY FILTER FABRIC
SCALE: N.T.S.
FILTER MEDIA (SEE NOTE 2)
SILT FENCE AS NEEDED 'UMP
FLOW G
cC
NOTES: ATER LEVEL
1. PRIOR TO INSTALLATION, MANUFACTURER SPECIFICATIONS OF FILTER MEDIA SHALL BE REVIEWED TO
ENSURE THAT DISCHARGE FROM FILTER MEDIA SHALL MEET OR EXCEED THE PROVISIONS OF THE CLEAN
WATER ACT.
2. ENSURE THAT PUMP PRESSURE DOES NOT EXCEED FILTER MEDIA PRESSURE RATING.
3. FILTER MEDIA MAY BE, BUT NOT LIMITED TO, SAND MEDIA FILTRATION DEVICES, RATED FILTER FABRIC 1
BAGS OR POLYMER BASED DEWATERING PRACTICES. _
4. PUMP STRAINER SHALL NOT BE IN CONTACT WITH BOTTOM OF POND.
�' I_ 1111=
BMP POND DEWATERING LOW POINT

10
Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk®Civil 3D®by Autodesk, Inc.v2022 Monday,09/18/2023
Hyd. No. 3 Peak Flow Period
Post Through SCM 13.70-11.90 = 1.80 - 2 hours
Hydrograph type = Reservoir Peak discharge = 46.12 cfs
Storm frequency = 100 yrs Time to peak = 12.00 hrs
Time interval = 2 min Hyd. volume = 52,044 cuft
Inflow hyd. No. = 2 - SCM Post-Develoftelservoir name = BMP Pond
Max. Elevation = 202.48 ft Max. Storage = 54,752 cuft
Storage Indication method used. Exfiltration extracted from Outflow.
Hydrograph Discharge Table (Printed values>=1.00%of Qp.)
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
11.90 66.44 201.85 3.988 2.667 3.988
11.93 76.68 << 202.14 19.70 2.728 19.70
11.97 75.18 202.37 36.30 2.776 36.30
12.00 59.59 202.48 << 46.12 2.801 46.12
12.03 37.73 202.48 46.03 2.800 46.03
12.07 20.87 202.40 39.14 2.783 39.14
12.10 13.00 202.30 30.84 2.761 30.84
12.13 10.71 202.21 24.10 2.742 24.10
12.17 10.27 202.14 19.41 2.727 19.41
12.20 9.854 202.09 16.06 2.716 16.06
12.23 9.434 202.05 13.73 2.708 13.73
12.27 9.011 202.02 11.89 2.701 11.89
12.30 8.583 201.99 10.44 2.696 10.44
12.33 8.153 201.97 9.279 2.691 9.279
12.37 7.721 201.95 8.343 2.687 8.343
12.40 7.287 201.93 7.541 2.684 7.541
12.43 6.850 201.92 6.848 2.681 6.848
12.47 6.409 201.91 6.223 2.678 6.223
12.50 5.968 201.89 5.665 2.675 5.665
12.53 5.561 201.88 5.134 2.673 5.134
Continues on next page...

11
Post Through SCM
Hydrograph Discharge Table
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
12.57 5.256 201.87 4.673 2.670 4.673
12.60 5.066 201.86 4.256 2.668 4.256
12.63 4.944 201.85 3.889 2.666 3.889
12.67 4.846 201.84 3.598 2.665 3.598
12.70 4.748 201.84 3.343 2.663 3.342
12.73 4.649 201.83 3.114 2.662 3.115
12.77 4.550 201.82 2.909 2.661 2.909
12.80 4.450 201.82 2.728 2.659 2.728
12.83 4.350 201.81 2.574 2.658 2.574
12.87 4.250 201.81 2.429 2.657 2.429
12.90 4.150 201.81 2.292 2.657 2.292
12.93 4.049 201.80 2.160 2.656 2.160
12.97 3.948 201.80 2.033 2.655 2.033
13.00 3.847 201.79 1.910 2.654 1.910
13.03 3.751 201.79 1.792 2.653 1.792
13.07 3.668 201.79 1.694 2.653 1.694
13.10 3.602 201.78 1.600 2.652 1.600
13.13 3.545 201.78 1.510 2.651 1.510
13.17 3.491 201.78 1.425 2.650 1.425
13.20 3.437 201.77 1.343 2.650 1.343
13.23 3.383 201.77 1.266 2.649 1.266
13.27 3.328 201.77 1.192 2.649 1.192
13.30 3.274 201.77 1.120 2.648 1.120
13.33 3.219 201.76 1.051 2.648 1.051
13.37 3.165 201.76 0.984 2.647 0.984
13.40 3.110 201.76 0.931 2.646 0.931
13.43 3.056 201.76 0.880 2.646 0.880
13.47 3.001 201.75 0.828 2.645 0.828
Continues on next page...

12
Post Through SCM
Hydrograph Discharge Table
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
13.50 2.946 201.75 0.776 2.645 0.776
13.53 2.892 201.75 0.724 2.644 0.724
13.57 2.844 201.75 0.672 2.644 0.672
13.60 2.800 201.74 0.620 2.643 0.620
13.63 2.760 201.74 0.570 2.643 0.570
13.67 2.721 201.74 0.521 2.642 0.521
13.70 2.682 201.74 0.473 2.642 0.473
...End

9/18/23,9:05 AM ECMDS 7.0
NORTH North American Green
AMERICAN 5401 St. Wendel-Cynthiana Rd.
Poseyville, Indiana 47633
GREEN Tel. [phone]
>Fax [phone]
www.nagreen.com
ECMDS v7.0
SPILLWAY ANALYSIS
>>>Grass Spillway
Name Grass Spillway
Discharge 46.12
Peak Flow Period 2
Channel Slope 0.33
Channel Bottom Width 20
Low Flow Liner
Retardence Class C 6-12 in
Vegetation Type Mix(Sod and Bunch)
Vegetation Density Very Good 80-95%
Soil Type Sand(SP)
Shoremax - Class C - Mix (Sod & Bunch) - Very Good 80-95%
Normal Permissible Calculated Safety Staple
Phase Reach Discharge Velocity Mannings N Remarks
Depth Shear Stress Shear Stress Factor Pattern
Shoremax w/ Straight 46.12 cfs 11.35 ft/s 0.2 ft 0.025 8.5 lbs/ft2 4.12 lbs/ft2 2.06 STABLE F
P300
Unvegetated
Underlying Straight 46.12 cfs 11.35 ft/s 0.2 ft 0.025 5.25 lbs/ft2 4.05 lbs/ft2 1.3 STABLE F
Substrate
Shoremax w/ Straight 46.12 cfs 11.07 ft/s 0.21 ft 0.027 14 lbs/ft2 4.23 lbs/ft2 3.31 STABLE F
P300 Reinforced
Vegetation
Underlying Straight 46.12 cfs 11.07 ft/s 0.21 ft 0.027 8.5 lbs/ft2 4.15 lbs/ft2 2.05 STABLE F
Substrate
https://ecmds.com/project/157518/spillway-analysis/251955/show 1/1

Project Name Riprap Dissipator#1 Date
Lancaster Sep,2023
DD Project No.
Location D&L Engineering, PLLC DL2202
Hoke County, North Carolina 150 S. Page Street Calculated By
Southern Pines, NC 28387 JLH
[phone] Checked By
JLH
STORM DESIGN: 25 Year
BACKGROUND: Use the E&S Control Planning& Design Manual, Section 8.06.
REFERENCE: (NCDEHNR, 1993)
Step 1. Minimum Tailwater Condition
Step 2. D-o= 18 in. Pipe diameter in inches
D-o= 1.50 ft. Pipe diameter in feet
Q-25= 9.09 cfs Pipe outlet(from drainage calculations)
d-50= 0.3 ft. from Figure 8.06 a
L-a= 10 ft. from Figure 8.06 a
Step 3. 3*D-o= 4.50 ft. 3 times the outlet pipe diameter
W = 11.50 ft. Pipe diameter+Apron length
Step 4. d-max 0.45 ft. Maximum Stone Diameter(1.5*d-50)in inches
d-max 5 in. Maximum Stone Diameter(1.5*d-50)in feet
Step 5. Thickness= 0.68 ft. Min.Apron Thickness With Filter Fabric(1.5*d-max)in feet
Thickness= 8 in. Min.Apron Thickness With Filter Fabric(1.5*d-max)in inches
DESIGN DIMENSIONS: Apron Dimensions Riprap
Length Width 3*D-o Thick Class
10 12 5 18in. B
TERMINOLOGY: Q10 = 10-Year Design Storm, Peak Discharge, (cfs)
D-o= Pipe Diameter, (in. &ft.)
d-50 = Mean Stone Diameter of Rip-Rap, (ft.)
L-a = Length of Rip-Rap Apron, (ft.)
3*D-o= Width of Rip-Rap Apron @ Pipe Outlet, (ft.)
W = Width of Rip-Rap Apron @ End of Apron, (ft.)
d-max= Maximum Stone Diameter of Rip-Rap, (ft. &in.)
Thickness= Thickness of Rip-Rap Apron With Filter Fabric, (ft. &in.)