SWA000186_Design Calculations_20230302

Stormwater Impact Analysis
6785 Reynolda Road
Pfafftown, NC 27040
Project No. 22-271
Prepared for:
COC Investments, LLC
2049 West Pine Street
Mount Airy, NC 27030
PILOT
SURVEYING & ENGINEERING
106 S. Depot Street
Suite D
Pilot Mountain, NC
(336-422-6741)
www.pilotse.com
Contact: [e-mail]

Table of Contents
ProjectNarrative....................................................................................................................................................... 3
SupportingInformation............................................................................................................................................. 4
Hydrology& Summary.............................................................................................................................................. 5
Detention Summary & Water Quality Calculations................................................................................................... 6
HydrographsModeling Report.................................................................................................................................. 7
Pre Development Drainage Area Map...................................................................................................................... 8
Post Development Drainage Area Map..................................................................................................................... 9
OutletProtection..................................................................................................................................................... 10
Anti -Float Block Calculations................................................................................................................................... 11
HydraflowModeling Summary................................................................................................................................ 12
Erosion Control Calculations................................................................................................................................... 13
Page 2 of 13

Project Narrative
The proposed project consists of the construction of six new outdoor self storage buildings and
an office. The site is located on Reynolda Road in Pfafftown, North Carolina. Existing
conditions onsite consist of an existing junk yard on the eastern side of the site with two
additional existing buildings along Reynolda Road, one of which is to be removed.
The site generally drains from east to west with a small portion of the developing area draining
to the east. There is a small stream running south to north located on the western side of the
property; no impacts are proposed.
In order to mitigate stormwater impacts from the construction of the project, one above ground
wet pond has been designed to treat runoff from the site in accordance with the North Carolina
Stormwater Manual and to detain post -development flow rates to be equal or less than pre -
development flow rates for the 2-, 10- and 25- year storm events.
A multi -phase erosion control plan has been designed to provide the required erosion and
sediment control protection during construction. Measures generally include silt fence, silt
fence outlets, utilization of the wet pond as a skimmer basin during construction and other inlet
and gravel protection measures. Phase one of the erosion control plan has been developed to
install perimeter measures and remove only the amount of existing site infrastructure
necessary to install the wet pond and skimmer and clear and grub the area to be developed.
Stage two progresses with the installation of infrastructure, and addresses erosion control
once the site has reached finished grade and installation of storm drainage piping and fill has
been placed.
In conclusion, as proposed the development as designed will meet stormwater quality
requirements and detention requirements as the pond meets the 2-, 10, and 25- year detention
from predevelopment to post development rates.
Detention Summary
POA #
2-Yr Storm cfs
10-Yr Storm cfs
25-Yr Storm cfs
1
5.59
2.69
-529/(o
18.89
14.34
-24%
28.71
26.41
-8%
2
1.63
1.51
-7%
5.16
3.99
-23%
7.76
5.74
-26%
Page 3 of 13

Supporting
Information
Page 4 of 13

556530
36' 11' 21" N
36o 11' 8" N
556580 556630 556680 556730
Map Scale: 1:1,980 if printed on A portrait (8.5" x 11") sheet.
Meters
$ N 0 25 50 100 150
Feet
0 50 100 200 300
Map projection: Web Mercator Conermordinates: WGS84 Edge tics: lfrM Zone 17N WGS84
usoA Natural Resources Web Soil Survey
Conservation Service National Cooperative Soil Survey
Hydrologic Soil Group —Forsyth County, North Carolina
(Pre_DA1)
5565M 556630 556680 5%730
556780
556780
v
556830
36o 11' 21" N
36o 11' 8" N
556830
v
12/12/2022
Pagel of 4

Hydrologic Soil Group —Forsyth County, North Carolina
(Pre_DA1)
MAP LEGEND
Area of Interest (AOI)
0
Area of Interest (AOI)
Soils
Soil Rating
Polygons
0
A
0
A/D
0
B
0
B/D
C
0
C/D
0
D
0
Not rated or not available
Soil Rating
Lines
r 0
A
r 0
A/D
B
B/D
N 0
C
r 0
C/D
r 0
D
r 0
Not rated or not available
Soil Rating
Points
0
A
0
A/D
0
B
0
B/D
❑ C
0 C/D
0 D
❑ Not rated or not available
Water Features
Streams and Canals
Transportation
— Rails
­0 Interstate Highways
US Routes
Major Roads
Local Roads
Background
D6 Aerial Photography
MAP INFORMATION
The soil surveys that comprise your AOI were mapped at
1:15,800.
Warning: Soil Map may not be valid at this scale.
Enlargement of maps beyond the scale of mapping can cause
misunderstanding of the detail of mapping and accuracy of soil
line placement. The maps do not show the small areas of
contrasting soils that could have been shown at a more detailed
scale.
Please rely on the bar scale on each map sheet for map
measurements.
Source of Map: Natural Resources Conservation Service
Web Soil Survey URL:
Coordinate System: Web Mercator (EPSG:3857)
Maps from the Web Soil Survey are based on the Web Mercator
projection, which preserves direction and shape but distorts
distance and area. A projection that preserves area, such as the
Albers equal-area conic projection, should be used if more
accurate calculations of distance or area are required.
This product is generated from the USDA-NRCS certified data as
of the version date(s) listed below.
Soil Survey Area: Forsyth County, North Carolina
Survey Area Data: Version 24, Sep 8, 2022
Soil map units are labeled (as space allows) for map scales
1:50,000 or larger.
Date(s) aerial images were photographed: Oct 17, 2020—Nov 3,
2020
The orthophoto or other base map on which the soil lines were
compiled and digitized probably differs from the background
imagery displayed on these maps. As a result, some minor
shifting of map unit boundaries may be evident.
usoA Natural Resources Web Soil Survey 12/12/2022
Conservation Service National Cooperative Soil Survey Page 2 of 4

Hydrologic Soil Group —Forsyth County, North Carolina
Pre_DA1
Hydrologic Soil Group
Map unit symbol
Map unit name
Rating
Acres in AOI
Percent of AOI
CIB
Clifford sandy loam, 2 to
A
2.0
19.0%
6 percent slopes
FaD
Fairview fine sandy
B
0.1
0.6%
loam, 10 to 15 percent
slopes
PoC
Poplar Forest fine sandy
B
4.3
40.4%
loam, 6 to 10 percent
slopes
PoF
Poplar Forest fine sandy
B
3.7
34.4%
loam, 15 to 45 percent
slopes
TmB
Tomlin loam, 2 to 6
B
0.6
5.6%
percent slopes
Totals for Area of Interest
10.7
100.0%
USDA Natural Resources Web Soil Survey 12/12/2022
Conservation Service National Cooperative Soil Survey Page 3 of 4

Hydrologic Soil Group —Forsyth County, North Carolina
Pre_DA1
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 12/12/2022
Conservation Service National Cooperative Soil Survey Page 4 of 4

0
556680
36o 11' 20" N
g
0
r
36o 11' 11" N
Hydrologic Soil Group —Forsyth County, North Carolina
(Pre_DA2)
556710 556740 556770 556800 556830
556680 556710 556740 556770 556800 556830
b
Map Scale: 1:1,420 if printed on A portrait (8.5" x 11") sheet.
Meters
$ N 0 20 40 80 120
Feet
0 50 100 200 300
Map projection: Web Mercator Conermordinates: WGS84 Edge tics: lfrM Zone 17N WGS84
usoA Natural Resources Web Soil Survey
Conservation Service National Cooperative Soil Survey
556M
36o 11' 20" N
g
0
36o 11' 11" N
556890
12/12/2022
Pagel of 4

Hydrologic Soil Group —Forsyth County, North Carolina
(Pre_DA2)
MAP LEGEND
Area of Interest (AOI)
0
Area of Interest (AOI)
Soils
Soil Rating
Polygons
0
A
0
A/D
0
B
0
B/D
C
0
C/D
0
D
0
Not rated or not available
Soil Rating
Lines
r 0
A
r 0
A/D
B
B/D
N 0
C
r 0
C/D
r 0
D
r 0
Not rated or not available
Soil Rating
Points
0
A
0
A/D
0
B
0
B/D
❑ C
0 C/D
0 D
❑ Not rated or not available
Water Features
Streams and Canals
Transportation
— Rails
­0 Interstate Highways
US Routes
Major Roads
Local Roads
Background
D6 Aerial Photography
MAP INFORMATION
The soil surveys that comprise your AOI were mapped at
1:15,800.
Warning: Soil Map may not be valid at this scale.
Enlargement of maps beyond the scale of mapping can cause
misunderstanding of the detail of mapping and accuracy of soil
line placement. The maps do not show the small areas of
contrasting soils that could have been shown at a more detailed
scale.
Please rely on the bar scale on each map sheet for map
measurements.
Source of Map: Natural Resources Conservation Service
Web Soil Survey URL:
Coordinate System: Web Mercator (EPSG:3857)
Maps from the Web Soil Survey are based on the Web Mercator
projection, which preserves direction and shape but distorts
distance and area. A projection that preserves area, such as the
Albers equal-area conic projection, should be used if more
accurate calculations of distance or area are required.
This product is generated from the USDA-NRCS certified data as
of the version date(s) listed below.
Soil Survey Area: Forsyth County, North Carolina
Survey Area Data: Version 24, Sep 8, 2022
Soil map units are labeled (as space allows) for map scales
1:50,000 or larger.
Date(s) aerial images were photographed: Oct 17, 2020—Nov 3,
2020
The orthophoto or other base map on which the soil lines were
compiled and digitized probably differs from the background
imagery displayed on these maps. As a result, some minor
shifting of map unit boundaries may be evident.
usoA Natural Resources Web Soil Survey 12/12/2022
Conservation Service National Cooperative Soil Survey Page 2 of 4

Hydrologic Soil Group —Forsyth County, North Carolina
Pre_DA2
Hydrologic Soil Group
Map unit symbol
Map unit name
Rating
Acres in AOI
Percent of AOI
CIB
Clifford sandy loam, 2 to
A
0.1
2.8%
6 percent slopes
PcF2
Pacolet clay loam, 15 to
B
0.2
10.2%
45 percent slopes,
moderately eroded
PoC
Poplar Forest fine sandy
B
0.1
4.3%
loam, 6 to 10 percent
slopes
TmB
Tomlin loam, 2 to 6
B
1.8
82.6%
percent slopes
Totals for Area of Interest
2.2
100.0%
USDA Natural Resources Web Soil Survey 12/12/2022
Conservation Service National Cooperative Soil Survey Page 3 of 4

Hydrologic Soil Group —Forsyth County, North Carolina
Pre_DA2
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 12/12/2022
Conservation Service National Cooperative Soil Survey Page 4 of 4

v
556600
36o 11' 20" N
I
0
36o 11' 9" N
556600 556640 556680 556720 556760
v
Map Scale: 1:1,740 if printed on A portrait (8.5" x 11") sheet.
Meters
$ N 0 25 50 100 150
Feet
0 50 100 200 300
Map projection: Web Mercator Conermordinates: WGS84 Edge tics: lfrM Zone 17N WGS84
usoA Natural Resources Web Soil Survey
Conservation Service National Cooperative Soil Survey
Hydrologic Soil Group —Forsyth County, North Carolina
(Post_DA1_2SCM)
556640 556680 556720 556760
556840
36o 11' 20" N
36o 1V9"N
556940
12/12/2022
Pagel of 4

Hydrologic Soil Group —Forsyth County, North Carolina
(Post_DA1_2SCM)
MAP LEGEND
Area of Interest (AOI)
0
Area of Interest (AOI)
Soils
Soil Rating
Polygons
0
A
0
A/D
0
B
0
B/D
C
0
C/D
0
D
0
Not rated or not available
Soil Rating
Lines
r 0
A
r 0
A/D
B
B/D
N 0
C
r 0
C/D
r 0
D
r 0
Not rated or not available
Soil Rating
Points
0
A
0
A/D
0
B
0
B/D
❑ C
0 C/D
0 D
❑ Not rated or not available
Water Features
Streams and Canals
Transportation
— Rails
­0 Interstate Highways
US Routes
Major Roads
Local Roads
Background
D6 Aerial Photography
MAP INFORMATION
The soil surveys that comprise your AOI were mapped at
1:15,800.
Warning: Soil Map may not be valid at this scale.
Enlargement of maps beyond the scale of mapping can cause
misunderstanding of the detail of mapping and accuracy of soil
line placement. The maps do not show the small areas of
contrasting soils that could have been shown at a more detailed
scale.
Please rely on the bar scale on each map sheet for map
measurements.
Source of Map: Natural Resources Conservation Service
Web Soil Survey URL:
Coordinate System: Web Mercator (EPSG:3857)
Maps from the Web Soil Survey are based on the Web Mercator
projection, which preserves direction and shape but distorts
distance and area. A projection that preserves area, such as the
Albers equal-area conic projection, should be used if more
accurate calculations of distance or area are required.
This product is generated from the USDA-NRCS certified data as
of the version date(s) listed below.
Soil Survey Area: Forsyth County, North Carolina
Survey Area Data: Version 24, Sep 8, 2022
Soil map units are labeled (as space allows) for map scales
1:50,000 or larger.
Date(s) aerial images were photographed: Oct 17, 2020—Nov 3,
2020
The orthophoto or other base map on which the soil lines were
compiled and digitized probably differs from the background
imagery displayed on these maps. As a result, some minor
shifting of map unit boundaries may be evident.
usoA Natural Resources Web Soil Survey 12/12/2022
Conservation Service National Cooperative Soil Survey Page 2 of 4

Hydrologic Soil Group —Forsyth County, North Carolina
Post_DA1_2SCM
Hydrologic Soil Group
Map unit symbol
Map unit name
Rating
Acres in AOI
Percent of AOI
CIB
Clifford sandy loam, 2 to
A
2.2
21.7%
6 percent slopes
PoC
Poplar Forest fine sandy
B
3.8
37.3%
loam, 6 to 10 percent
slopes
PoF
Poplar Forest fine sandy
B
2.8
27.3%
loam, 15 to 45 percent
slopes
TmB
Tomlin loam, 2 to 6
B
1.4
13.7%
percent slopes
Totals for Area of Interest
10.3
100.0%
USDA Natural Resources Web Soil Survey 12/12/2022
Conservation Service National Cooperative Soil Survey Page 3 of 4

Hydrologic Soil Group —Forsyth County, North Carolina
Post_DA1_2SCM
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 12/12/2022
Conservation Service National Cooperative Soil Survey Page 4 of 4

3: Hydrologic Soil Group —Forsyth County, North Carolina 3:
(Post_DA1 _Byp) o
556530 556550 556570 556590 556610 556630 556650 556670
36o 11' 19" N I 36o 11' 19" N
PoF
FaD
Ap
o
- 5
r
0
o
_ 4
y
o IW� o
1
Soil N1aN may not M valiel at this scale.
360 11' 12" N - I 360 11' 12" N
556530 556550 .70 556590 556510 556630 556650 556670
o b
Map Scale: 1:1,040 if printed on A portrait (8.5" x 11") sheet.
Meters
$ N 0 15 30 60 90 $
Feet
0 50 100 200 300
Map projection: Web Mercator Conermordinates: WGS84 Edge tics: lfrM Zone 17N WGS84
usoA Natural Resources Web Soil Survey 12/13/2022
Conservation Service National Cooperative Soil Survey Pagel of 4

Hydrologic Soil Group —Forsyth County, North Carolina
(Post_DA1 _Byp)
MAP LEGEND
Area of Interest (AOI)
0
Area of Interest (AOI)
Soils
Soil Rating
Polygons
0
A
0
A/D
0
B
0
B/D
C
0
C/D
0
D
0
Not rated or not available
Soil Rating
Lines
r 0
A
r 0
A/D
B
B/D
N 0
C
r 0
C/D
r 0
D
r 0
Not rated or not available
Soil Rating
Points
0
A
0
A/D
0
B
0
B/D
❑ C
0 C/D
0 D
❑ Not rated or not available
Water Features
Streams and Canals
Transportation
— Rails
­0 Interstate Highways
US Routes
Major Roads
Local Roads
Background
D6 Aerial Photography
MAP INFORMATION
The soil surveys that comprise your AOI were mapped at
1:15,800.
Warning: Soil Map may not be valid at this scale.
Enlargement of maps beyond the scale of mapping can cause
misunderstanding of the detail of mapping and accuracy of soil
line placement. The maps do not show the small areas of
contrasting soils that could have been shown at a more detailed
scale.
Please rely on the bar scale on each map sheet for map
measurements.
Source of Map: Natural Resources Conservation Service
Web Soil Survey URL:
Coordinate System: Web Mercator (EPSG:3857)
Maps from the Web Soil Survey are based on the Web Mercator
projection, which preserves direction and shape but distorts
distance and area. A projection that preserves area, such as the
Albers equal-area conic projection, should be used if more
accurate calculations of distance or area are required.
This product is generated from the USDA-NRCS certified data as
of the version date(s) listed below.
Soil Survey Area: Forsyth County, North Carolina
Survey Area Data: Version 24, Sep 8, 2022
Soil map units are labeled (as space allows) for map scales
1:50,000 or larger.
Date(s) aerial images were photographed: Oct 17, 2020—Nov 3,
2020
The orthophoto or other base map on which the soil lines were
compiled and digitized probably differs from the background
imagery displayed on these maps. As a result, some minor
shifting of map unit boundaries may be evident.
usoA Natural Resources Web Soil Survey 12/13/2022
Conservation Service National Cooperative Soil Survey Page 2 of 4

Hydrologic Soil Group —Forsyth County, North Carolina
Post_DA1 _Byp
Hydrologic Soil Group
Map unit symbol
Map unit name
Rating
Acres in AOI
Percent of AOI
FaD
Fairview fine sandy
B
0.1
4.1 %
loam, 10 to 15 percent
slopes
PoC
Poplar Forest fine sandy
B
0.5
35.8%
loam, 6 to 10 percent
slopes
PoF
Poplar Forest fine sandy
B
0.9
60.1 %
loam, 15 to 45 percent
slopes
Totals for Area of Interest
1.6
100.0%
USDA Natural Resources Web Soil Survey 12/13/2022
Conservation Service National Cooperative Soil Survey Page 3 of 4

Hydrologic Soil Group —Forsyth County, North Carolina
Post_DA1 _Byp
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 12/13/2022
Conservation Service National Cooperative Soil Survey Page 4 of 4

0
556680
36o 11' 20" N
g
0
r
36o 11' 11" N
Hydrologic Soil Group —Forsyth County, North Carolina
(Post_DA2_Byp)
556710 556740 556770 556800 556830
556680 556710 556740 556770 556800 556830
b
Map Scale: 1:1,420 if printed on A portrait (8.5" x 11") sheet.
Meters
$ N 0 20 40 80 120
Feet
0 50 100 200 300
Map projection: Web Mercator Conermordinates: WGS84 Edge tics: lfrM Zone 17N WGS84
usoA Natural Resources Web Soil Survey
Conservation Service National Cooperative Soil Survey
556M
36o 11' 20" N
g
0
36o 11' 11" N
556890
12/13/2022
Pagel of 4

Hydrologic Soil Group —Forsyth County, North Carolina
(Post_DA2_Byp)
MAP LEGEND
Area of Interest (AOI)
0
Area of Interest (AOI)
Soils
Soil Rating
Polygons
0
A
0
A/D
0
B
0
B/D
C
0
C/D
0
D
0
Not rated or not available
Soil Rating
Lines
r 0
A
r 0
A/D
B
B/D
N 0
C
r 0
C/D
r 0
D
r 0
Not rated or not available
Soil Rating
Points
0
A
0
A/D
0
B
0
B/D
❑ C
0 C/D
0 D
❑ Not rated or not available
Water Features
Streams and Canals
Transportation
— Rails
­0 Interstate Highways
US Routes
Major Roads
Local Roads
Background
D6 Aerial Photography
MAP INFORMATION
The soil surveys that comprise your AOI were mapped at
1:15,800.
Warning: Soil Map may not be valid at this scale.
Enlargement of maps beyond the scale of mapping can cause
misunderstanding of the detail of mapping and accuracy of soil
line placement. The maps do not show the small areas of
contrasting soils that could have been shown at a more detailed
scale.
Please rely on the bar scale on each map sheet for map
measurements.
Source of Map: Natural Resources Conservation Service
Web Soil Survey URL:
Coordinate System: Web Mercator (EPSG:3857)
Maps from the Web Soil Survey are based on the Web Mercator
projection, which preserves direction and shape but distorts
distance and area. A projection that preserves area, such as the
Albers equal-area conic projection, should be used if more
accurate calculations of distance or area are required.
This product is generated from the USDA-NRCS certified data as
of the version date(s) listed below.
Soil Survey Area: Forsyth County, North Carolina
Survey Area Data: Version 24, Sep 8, 2022
Soil map units are labeled (as space allows) for map scales
1:50,000 or larger.
Date(s) aerial images were photographed: Oct 17, 2020—Nov 3,
2020
The orthophoto or other base map on which the soil lines were
compiled and digitized probably differs from the background
imagery displayed on these maps. As a result, some minor
shifting of map unit boundaries may be evident.
usoA Natural Resources Web Soil Survey 12/13/2022
Conservation Service National Cooperative Soil Survey Page 2 of 4

Hydrologic Soil Group —Forsyth County, North Carolina
Post_DA2_Byp
Hydrologic Soil Group
Map unit symbol
Map unit name
Rating
Acres in AOI
Percent of AOI
CIB
Clifford sandy loam, 2 to
A
0.1
4.5%
6 percent slopes
PcF2
Pacolet clay loam, 15 to
B
0.2
16.4%
45 percent slopes,
moderately eroded
PoC
Poplar Forest fine sandy
B
0.1
6.8%
loam, 6 to 10 percent
slopes
TmB
Tomlin loam, 2 to 6
B
1.0
72.2%
percent slopes
Totals for Area of Interest
1.3
100.0%
USDA Natural Resources Web Soil Survey 12/13/2022
Conservation Service National Cooperative Soil Survey Page 3 of 4

Hydrologic Soil Group —Forsyth County, North Carolina
Post_DA2_Byp
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 12/13/2022
Conservation Service National Cooperative Soil Survey Page 4 of 4

12/12/22, 11:08 PM Precipitation Frequency Data Server
NOAA Atlas 14, Volume 2, Version 3
1' Location name: Pfafftown, North Carolina, USA*
Latitude: 36.1871°, Longitude:-80.3679° 6W�
Elevation: 948.23 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/hour)1
Average recurrence interval (years)
1 2 5 10 25 50 100 200 500 1000
5-min 4.43 5.27 6.22 6.86 7.66 8.18 8.68 9.12 9.64 10. 00
(4.09-4.81) 1 (4.87-5.74) 11 (5.74-6.77) 11 (6.32-7.46) 1 (7.01-8.32) 1 (7.44-8.90) 11 (7.84-9.44) 1 (8.18-9.96) 1 (8.53-10.6) 11 (8.76-11.0)
3.54
4.22
4.97
5.50
6.10
6.52
6.89
7.22
7.62
7.87
10-min
(3.27-3.84)
1 (3.90-4.59)
11 (4.59-5.42)
11 (5.06-5.97)
1 (5.58-6.62)
1 (5.93-7.09) 11
(6.23-7.51)
1 (6.48-7.90)
1 (6.75-8.36)
11 (6.90-8.68)
2.95
3.53
4.20
4.63
5.15
5.50
5.81
6.08
6.39
6.58
15-min
(2.73-3.20)
1 (3.27-3.84)
11 (3.87-4.57)
11 (4.26-5.04)
1 (4.72-5.60)
1 (5.00-5.98) 11
(5.25-6.32)
1 (5.45-6.64)
1 (5.66-7.02)
11 (5.77-7.26)
2.02
2.44
2.98
3.36
3.82
4.14
4.45
4.73
5.09
5.33
30-min
(1.87-2.19)
1 (2.26-2.66)
11 (2.75-3.25)
11 (3.09-3.65)
1 (3.49-4.14)
1 (3.77-4.51) 11
(4.02-4.84)
1 (4.24-5.17)
1 (4.51-5.58)
11 (4.67-5.88)
1.26
1.53
1.91
2.19
2.54
2.81
3.06
3.32
3.65
3.89
60-min
(1.1 7-1.37)
1 (1.42-1.67)
(1.76-2.08)
11 (2.01-2.38)
1 (2.33-2.76)
1 (2.55-3.05)
(2.77-3.34)
1 (2.98-3.63)
1 (3.23-4.00)
11 (3.41-4.29)
0.742
0.902
7 1.14
1.31
1.55
1.73
7 1.91
2.09
2.34
7 2.53
2-hr
(0.684-0.810)
(0.831-0.986)
(1.04-1.24)
11 (1.20-1.43)
1 (1.41-1.68)
1 (1.56-1.88) 11
(1.71-2.09)
1 (1.86-2.29)
1 (2.05-2.57)
11 (2.19-2.79)
0.531
0.647
0.815
0.943
1.12
115
1.38
112
1.71
1.85
3-hr
(0.490-0.581)
(0.597-0.708)
(0.751-0.890)
(0.864-1.03)
1 (1.01-1.21)
1 (1.13-1.36) 11
(1.24-1.51)
1 (1.35-1.66)
1 (1.49-1.87)
11 (1.60-2.04)
0.327
0.396
0.499
0.579
0.688
0.777
0.867
0.960
1.09
1.19
6-hr
(0.301-0.357)
(0.366-0.434)
(0.459-0.546)
(0.530-0.632)
(0.626-0.750)
(0.700-0.846)
(0.775-0.944)
(0.847-1.05)
1 (0.946-1.19)
(1.02-1.31)
0.196
0.237
0.299
0.349
0.418
0.475
0.535
0.597
0.686
0.757
12-hr
(0.180-0.214)
(0.218-0.260)
(0.275-0.327)
(0.319-0.380)
(0.379-0.454)
(0.427-0.514)
(0.476-0.578)
(0.525-0.646)
(0.592-0.743)
(0.643-0.822)
0.118
0.143
0.181
0.210
0.252
0.286
0.322
0.360
0.413
0.457
24-hr
(0.110-0.128)
(0.132-0.155)
(0.167-0.195)
(0.194-0.227)
(0.231-0.272)
(0.262-0.309)
(0.293-0.348)
(0.325-0.389)
(0.370-0.447)
(0.406-0.495)
0.069
0.084
0.104
0.121
0.144
0.162
0.180
0.200
0.227
0.249
2{iay
(0.064-0.075)
(0.078-0.090)
(0.097-0.113)
(0.112-0.130)
(0.132-0.154)
(0.149-0.174)
(0.165-0.194)
(0.182-0.216)
(0.206-0.245)
(0.224-0.270)
0.049
0.059
0.074
0.085
0.101
0.114
0.127
0.140
0.160
0.175
3tlay
(0.046-0.053)
(0.055-0.063)
(0.069-0.079)
(0.079-0.091)
(0.093-0.108)
(0.105-0.122)
(0.116-0.136)
(0.128-0.151)
(0.144-0.172)
(0.157-0.189)
0.039
0.047
0.058
0.067
0.080
0.090
0.100
0.111
0.126
0.138
4tlay
(0.036-0.042)
(0.044-0.050)
(0.054-0.062)
(0.063-0.072)
(0.074-0.085)
(0.083-0.096)
(0.092-0.107)
(0.101-0.119)
(0.114-0.136)
(0.124-0.149)
0.025
0.030
0.037
0.042
0.050
0.056
0.062
0.068
0.077
0.084
7{iay
(0.024-0.027)
(0.028-0.032)
(0.035-0.040)
(0.040-0.045)
(0.046-0.053)
(0.052-0.060)
(0.057-0.066)
(0.063-0.073)
(0.070-0.083)
(0.076-0.090)
0.020
0.024
F029
0.033
0.039
0.043
0.047
0.052
0.058
0.063
10-day
(0.019-0.022)
(0.023-0.026)
(0.027-0.031)
(0.031-0.035)
(0.036-0.041)
(0.040-0.046)
(0.044-0.050)
(0.048-0.055)
(0.053-0.062)
(0.057-0.067)
0.014
0.016
0.019
0.022
0.025
0.027
0.030
0.033
0.036
0.039
20-day
(0.013-0.014)
(0.015-0.017)
(0.018-0.020)
(0.020-0.023)
(0.023-0.026)
(0.026-0.029)
(0.028-0.032)
(0.030-0.035)
(0.033-0.039)
(0.036-0.042)
0.011
0.013
0.015
0.017
0.019
0.021
0.023
0.024
0.026
0.028
30-day
(0.011-0.012)
(0.013-0.014)
(0.015-0.016)
(0.016-0.018)
(0.018-0.020)
(0.020-0.022)
(0.021-0.024)
(0.023-0.025)
(0.025-0.028)
(0.026-0.029)
0.009
0.011
0.013
0.014
0.016
0.017
0.018
0.019
0.021
0.022
45-day
(0.009-0.010)
(0.011-0.012)
(0.012-0.013)
(0.013-0.015)
(0.015-0.016)
(0.016-0.018)
(0.017-0.019)
(0.018-0.020)
(0.019-0.022)
(0.020-0.023)
0.008
0.010
0.011
0.012
0.014
0.014
0.015
0.016
0.017
0.018
60-day
(0.008-0.009)
(0.010-0.010)
(0.011-0.012)
(0.012-0.013)
(0.013-0.014)
(0.014-0.015)
(0.015-0.016)
(0.015-0.017)
(0.016-0.018)
1 (0.017-0.019)
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 PIMP values.
Please refer to NOAAAtlas 14 document for more information.
Back to Top
PF graphical
https://hdsc.nws.noaa.gov/hdsc/pfds/pfds_printpage.html?lat=36.1871 & Ion =-80.3679&data=intensity&units=english&series=pds 1 /4

12/12/22, 11:08 PM Precipitation Frequency Data Server
PD5-based intensity -duration -frequency (IDF) curves
Latitude: 35.1871°, Longitude: -30.3679'
M 61616IM1
1.000
41
C
3fa OX
0.0011
t t Jr t L N N O r{4 N rq rq rq N rq N Alb A q r, O O O Ln O
,1 r-I rn ro 1-4N rn v Ln
Duration
10.000
1.000
ZI
m
.c
0.100
0
49
0.010
a
0.001 1 1 1 1 1 1 1 1 1 1
1 2 5 10 25 50 100 200 500 1000
Average recurrence interval (years)
NOAA Atlas 14, Volume 2, Version 3 Created (GMT): Tue Dec 13 04:08=33 2022
Back to Top
Maps & aerials
Small scale terrain
Average recurrence
ml erva I
{years}
— 1
2
— 5
10
— 25
60
100
200
500
1000
Duration
— 6-min —
2-day
— 10-min —
3-day
15-min —
d-dmy
— 3C-rnw —
7-d ay
— 6 Wain —
1 o-day
— 2fir —
20-day
— 3-rr —
30-day
— Bfir —
45-day
— 12-n r —
60-day
24-nr
https://hdsc.nws.noaa.gov/hdsc/pfds/pfds_printpage.htmI?Iat=36.1871 &Ion=-80.3679&data=intensity&units=engIish&series=pds 2/4

12/12/22, 11:08 PM
Precipitation Frequency Data Server
sta
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https://hdsc.nws.noaa.gov/hdsc/pfds/pfds_printpage.html?lat=36.1871 & Ion =-80.3679&data=intensity&units=english&series=pds 3/4

12/12/22, 11:08 PM
Precipitation Frequency Data Server
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/hdsc/pfds/pfds_printpage.html?lat=36.1871 & Ion =-80.3679&data=intensity&units=english&series=pds 4/4

12/12/22, 11:08 PM Precipitation Frequency Data Server
NOAA Atlas 14, Volume 2, Version 3
Location name: Pfafftown, North Carolina, USA*�'
Latitude: 36.1871°, Longitude:-80.3679°
Elevation: 948.23 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
11 PDS-based point precipitation freauencv estimates with 90% confidence intervals (in inches)' 11
Average recurrence interval (years)
1 2 5 10 25 50 100 200 500 1000
5-min 0.369 0.439 0.518 0.572 0.638 0.682 0.723 0.760 0.803 0.833
(0.341-0.401) (0.406-0.478) (0.478-0.564) (0.527-0.622) (0.584-0.693) (0.620-0.742) (0.653-0.787) (0.682-0.830) (0.711-0.881) (0.730-0.91
0.590
0.703
0.829
0.916
1.02
1.09
1.15
1.20
1.27
1.31
10-min
(0.545-0.640)
(0.650-0.765)
(0.765-0.903)
(0.843-0.995)
(0.930-1.10)
(0.988-1.18)
1 (1.04-1.25) 11
(1.08-1.32)
1 (1.13-1.39)
11 (1.15-1.45)
0.738
0.883
1.05
1.16
1.29
1.38
1.45
1.52
1.60
1.65
15-min
(0.682-0.800)
(0.817-0.961)
(0.968-1.14)
11 (1.07-1.26) 11
(1.18-1.40)
1 (1.25-1.50)
1 (1.31-1.58) 11
(1.36-1.66)
1 (1.42-1.75)
11 (1.44-1.82)
1.01
1.22
1.49
1.68
1.91
2.07
2.22
2.37
2.54
2.67
30-min
(0.934-1.10)
(1.13-1.33)
(1.38-1.62)
(1.55-1.82)
(1.75-2.07)
(1.88-2.25)
(2.01-2.42)
(2.12-2.59)
(2.25-2.79)
(2.34-2.94)
1.26
1.63
1.91
2.19
2.64
2.81
3.06
3.32
3.66
3.89
60-min
(1.17-1.37)
(1.42-1.67)
(1.76-2.08)
(2.01-2.38)
(2.33-2.76)
(2.55-3.05)
(2.77-3.34)
(2.98-3.63)
(3.23-4.00)
(3.41-4.29)
1.49
1.81
2.27
2.62
3.09
3.46
3.82
4.18
4.68
6.06
2-hr
(1.37-1.62)
(1.66-1.97)
(2.09-2.48)
(2.40-2.86)
(2.81-3.37)
(3.12-3.77)
(3.42-4.17)
(3.71-4.58)
(4.09-5.14)
(4.37-5.58)
1.60
1.94
2.45
2.83
3.35
3.75
4.16
4.57
5.12
5.56
3-hr
(1.47-1.74)
(1.79-2.13)
(2.25-2.67)
(2.60-3.09)
(3.04-3.65)
(3.39-4.08)
(3.72-4.53)
(4.05-4.99)
(4.48-5.62)
(4.80-6.12)
1.96
2.37
2.99
3.47
4.12
4.66
6.19
6.76
6.63
7.14
6-hr
(1.81-2.14)
(2.19-2.60)
(2.75-3.27)
(3.18-3.78)
(3.75-4.49)
(4.19-5.07)
(4.64-5.65)
(5.07-6.26)
(5.66-7.13)
(6.11-7.83)
2.36
2.86
3.61
4.20
6.04
6.72
6.44
7.19
8.26
9.13
12-hr
(2.17-2.58)
(2.63-3.13)
(3.31-3.94)
(3.85-4.58)
(4.57-5.47)
(5.15-6.19)
(5.73-6.97)
(6.32-7.79)
(7.13-8.96)
(7.75-9.90)
2.84
3.43
4.33
5.05
6.05
6.87
7.73
8.64
9.92
11.0
24-hr
(2.63-3.07)
(3.18-3.72)
(4.00-4.69)
(4.66-5.46)
(5.55-6.54)
(6.28-7.42)
(7.03-8.35)
(7.80-9.34)
(8.89-10.7)
(9.76-11.9)
3.33
4.01
6.01
6.80
6.89
7.76
8.66
9.60
10.9
12.0
2{iay
(3.09-3.58)
(3.73-4.32)
(4.66-5.40)
(5.38-6.24)
(6.36-7.41)
(7.14-8.35)
(7.94-9.33)
(8.75-10.4)
(9.87-11.8)
(10.7-13.0)
3.63
4.26
6.30
6.13
7.26
8.18
9.13
10.1
11.6
12.6
3tlay
(3.29-3.79)
(3.96-4.57)
(4.93-5.69)
(5.69-6.57)
(6.72-7.79)
(7.54-8.78)
(8.37-9.81)
(9.23-10.9)
(10.4-12.4)
(11.3-13.6)
3.73
4.49
5.59
6.45
7.64
8.60
9.59
10.6
12.1
13.2
4tlay
(3.49-4.00)
(4.20-4.82)
(5.21-5.98)
(6.00-6.90)
(7.08-8.18)
(7.93-9.22)
(8.81-10.3)
(9.70-11.4)
(10.9-13.0)
(11.9-14.3)
4.26
6.10
6.24
7.14
8.38
9.37
10.4
11.6
12.9
14.1
7{iay
(3.99-4.55)
(4.77-5.45)
(5.83-6.66)
(6.66-7.62)
(7.79-8.94)
(8.67-10.0)
(9.59-11.1)
(10.5-12.3)
(11.8-13.9)
(12.7-15.2)
4.86
6.79
7.01
7.96
9.26
10.3
11.3
12.4
13.9
16.1
10tlay
(4.57-5.17)
(5.45-6.17)
(6.58-7.45)
(7.46-8.47)
(8.65-9.84)
(9.57-10.9)
(10.5-12.1)
(11.5-13.3)
(12.7-14.9)
(13.7-16.2)
6.54
7.75
9.21
10.4
11.9
13.2
14.4
15.6
17.3
18.6
20tlay
(6.18-6.93)
(7.33-8.21)
(8.70-9.76)
(9.78-11.0)
(11.2-12.6)
(12.3-13.9)
(13.4-15.3)
(14.5-16.6)
(16.0-18.5)
(17.1-19.9)
8.11
9.66
11.1
12.3
13.9
16.1
16.2
17.4
18.9
20.1
30tlay
(7.72-8.52)
(9.09-10.0)
(10.6-11.7)
(11.7-12.9)
(13.2-14.6)
(14.2-15.8)
(15.3-17.1)
(16.4-18.3)
(17.7-20.0)
(18.7-21.2)
10.2
12.0
13.8
16.1
16.9
18.2
19.4
20.7
22.3
23.6
45tlay
(9.78-10.7)
(11.5-12.6)
(13.2-14.4)
(14.4-15.8)
(16.0-17.6)
(17.3-19.0)
(18.4-20.4)
(19.5-21.7)
(21.0-23.4)
(22.0-24.8)
12.2
14.3
16.2
17.6
19.5
20.8
22.1
23.4
25.0
26.2
60tlay
(11.7-12.7)
(13.7-14.9)
(15.5-16.9)
(16.9-18.4)
(18.6-20.3)
(19.9-21.8)
(21.1-23.2)
(22.2-24.5)
(23.6-26.2)
(24.7-27.5)
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 PIMP values.
Please refer to NOAAAtlas 14 document for more information.
Back to Top
PF graphical
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12/12/22, 11:08 PM Precipitation Frequency Data Server
Pas -based depth -duration -frequency (DDF) curves
Latitude: 36.1871`, Longitude: -80-3679'
M:11
25
c
t 20
4-
a
di
U
15
49
10
CL
a
5
0
t t Jr t L N N O r{4 N rq rq rq N rq N �5 lb A q O O O Ln O
,1 r-I rn ro � N rn v Ln
Duration
30
25
c
s 20
a
m
a 15
A,
49
a
,� 10
CL
a
y
f
------------
.... ............
1 2 5 10 25 50 100 200 500 1000
Average recurrence interval (years)
NOAA Atlas 14, VoIume 2, Version 3 Created (GMT): Tue Dec 13 04:07:57 2022
Back to Top
Maps & aerials
Small scale terrain
Average recurrence
ml erva I
f years}
— 1
— 5
— 14
— 25
64
100
200
500
1000
Duration
— 6-min —
2-day
— 14-min —
3-day
15-min —
d-dmy
— 3C-rnw —
7-d ay
— 6 Wain —
10-day
— 2fir —
20-day
— 3-rr —
30-day
— Bfir —
45-day
— 12-n r —
60-day
24-nr
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12/12/22, 11:08 PM
Precipitation Frequency Data Server
sta
I
f' ?Q irlli
,Pfaltown ,
Large scale terrain
* Lynchburg Al
Blacksburg Roanoke
Bristol
winston-
• . Uuii7am
k reenshoro •
r:•ii r_1it,=17e11 Ral2igl'
Itp
•Asl7erille NORTH C A R 0 L I N A
100km Charlotte
Fayetteville
6 mi ja-
Large scale map
Lynchburg
Blacksburg ;,Roanoke
l r'
ort Bristol
Johnson Gity
in! l"Greensboroarham
J,Raieigh
Carolina
' f arl Otte
100km
Fettevi Ile
Large scale aerial
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12/12/22, 11:08 PM
Precipitation Frequency Data Server
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National Oceanic and Atmospheric Administration
National Weather Service
National Water Center
1325 East West Highway
Silver Spring, MD 20910
Questions?: [e-mail]
Disclaimer
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Hydrology &
Summary
Page 5 of 13

PRE -DEVELOPMENT HYDROLOGIC CALCULATIONS
For: COC INVESTMENTS, LLC
2049 WEST PINE STREET
MOUNT AIRY, NC 27030
Pfafftown Self Storage
.PILOT
SURVEYING & ENGINEERING
Project Number: 22-271
By: Cory George, PE, PLS
106 S. Depot Street
Suite D
Pilot Mountain, NC 27041

PILOT
URVEYING .4N❑ I'i. �,.i F.GRING
Project Name: Pfafftown Self Storage
Project Numbe 22-271
SUMMARY
PRE DEVELOPMENT SUMMARY
Date: 12/14/2022
Calculated By: JCG
Subbasin ID
Drainage Area Breakdown [acres]
Impervious Open Wooded
Total Area
[acres]
SCS CN
Tc [min]
DA-1
1.31
6.61
2.79
10.71
60
11.92
DA-2
0.00
2.15
0.00
2.15
60
5.00
12.86

P1LOT
.l1R VEYING ANG ENGINE EPING
Project Name: Pfafftown Self Storage
Project Number: 22-271
Subbasin ID: DA-1
SCS CURVE NUMBERS
(REF: SCS TR-55).
HYDROLOGIC CALCULATIONS
HSG Impervious Open Wooded Pond
A 98 39 30 100
B 98 61 55 100
C 98 74 70 100
D 98 80 77 100
HSG A = 19%
HSG B = 81%
HSG C = 0%
HSG D = 0%
Cover Condition SCS CN Comments
Impervious 98
Open 57 Assume good condition
Wooded 50 Assume good condition
Pond 100
SITE IMPERVIOUS BREAKDOWN
Contributing Area
Area [sf]
Area [ac]
Building
0.00
Offsite
0.00
Parking
0.00
Misc
57,267
1.31
Total
57,267
1.31
WATERSHED BREAKDOWN
Date: 12/14/2022
Calculated By: JCG
Contributing Area SCS CN Area [sf] Area [ac] Comments
Impervious
Open
98
57,267
1.31
57
287,723
6.61 Assume good condition
Wooded
50
121,357
2.79 Assume good condition
Open Water
100
0
0.00
Total Area =1 10.71 Jacres
=1 0.0167 sq mi
Composite SCS CN = 60
% Impervious = 12.28%

TIME OF CONCENTRATION
REF: SCS TR-55 .
Segment 1: Overland Flow
Length =
Upstream Invert =
Downstream Invert =
Slope =
Manning's n =
P (2-year/24-hour) =
Segment Time =
100
ft
ft
ft
ft/ft
948.50
941.00
0.0750
0.24
den-
3.43
inch
1 8.12
Imin
Segment 2: Concentrated Flow
Length =
725
ft
Upstream Invert =
941.00
ft
Downstream Invert =
897.00
ft
Slope =
0.0607
ft/ft
Paved? =
No
Velocity =
3.97
ft/sec
Segment Time =
3.04
min
Segment 3: Channel Flow
Length =
Upstream Invert =
Downstream Invert =
Slope =
Manning's n = i
Flow Area =
Wetted Perimeter =
Channel Velocity =
Segment Time =
Segment 4: Channel o�
Length =
Upstream Invert =
Downstream Invert =
Slope =
Manning's n =
Flow Area =
Wetted Perimeter =
Channel Velocity =
Segment Time =
wn,
ft
(REF: Natural Channel Desi
ft
Design criteria for stabilized
ft
is 3.5-6 ft/sec
ft/ft
Assumed Bottom Width=�
natural c anne
Assumed Depth=
ft
ft
min
Time of Concentration = 11.92 min
(REF: Natural Channel Desi
Design cn ena tor stabilized
is 3.5-6 ff/sec
Assumed Bo om Width=
Assumed Depth=

P1LOT
.l1R VEYING ANG ENGINE EPING
Project Name: Pfafftown Self Storage
Project Number: 22-271
Subbasin ID: DA-2
SCS CURVE NUMBERS
(REF: SCS TR-55).
HYDROLOGIC CALCULATIONS
HSG Impervious Open Wooded Pond
A 98 39 30 100
B 98 61 55 100
C 98 74 70 100
D 98 80 77 100
HSG A - 3%
HSG B
HSG C - 0%
HSG D - 0%
Cover Condition SCS CN Comments
Impervious j8
Open 60 Assume good condition
Wooded 54 Assume good condition
Pond 100
SITE IMPERVIOUS BREAKDOWN
Contributine Area Area isfl Area lacl
Building
Roads
0
0
0.00
0.00
Parking
0
0.00
Misc
0
0.00
Total
0
0.00
WATERSHED BREAKDOWN
Contributiniz Area
Date: 12/14/2022
Calculated By: JCG
SCS CN Area Isfl Area facl Comments
Impervious
Open
78
U
0.00
60
93,806
2.15 Assume good condition
Wooded
54
0
0.00 Assume good condition
Open Water
100
0
0.00
Total Area = 2.15 acres
= 0.0034 sq mi
Composite SCS CN = 60
% Impervious

TIME OF CONCENTRATION
REF: SCS TR-55 .
Length =
100
ft
Upstream Invert =
948.50
ft
Downstream Invert =
947.00
ft
Slope =
0.0150
ft/ft
Manning's n =
0.01
gravel & bare soil
P (2-year/24-hour) =
3.43
inches (Pfafftown,
Segment Time =1
1.31
Imin
Length =
144
ft
Upstream Invert =
947.00
ft
Downstream Invert =
943.00
ft
Slope =
0.0278
ft/ft
Paved? =
No
Velocity =
2.69
ft sec
Segment Time
0.89
min
Time of Concentration = 5.00 min

dNPILOT
�� SfIRVEYING ANO ENGINEERING
Project Name: Pfafftown Self Storage
Project Numbe 22-271
POST DEVELOPMENT SUMMARY
Date: 12/14/2022
Calculated By: JCG
SUMMARY
Subbasin ID Drainage Area Breakdown [acres] Total Area SCS CN Tc [min]
Impervious Open Wooded [acres]
DA1- to SCM
4.89
4.71
0.70
10.30
76
5.00
DA1- BYP
0.06
0.21
1.19
1.46
58
9.01
DA2 - BYP
0.13
1.22
0.00
1.34
64
5.00
111.766

PI LOT
SURVEYING I1N° ENGINEERING
Project Name:
Pfafftown Self Storage
Project Number:
22-271
Subbasin ID:
DA1 - to SCM
SCS CURVE NUMBERS
(REF: SCS TR-55).
HSG
HYDROLOGIC CALCULATIONS
A
98
B
98
C
98
D
98
HSG A = 22%
HSG B = 78%
HSG C = 0%
HSG D = 0%
Cover Condition
SCS CN
Date: 12/14/2022
Calculated By: JCG
pen
wooaea
rona
39
30
100
61
55
100
74
70
100
80
77
100
Comments
Impervious
98
Open
56
Assume good condition
Wooded
50
Assume good condition
Pond
100
-
OFF SITE IMPERVIOUS BREAKDOWN
Contributing Area Area fsfl Area facl
Building
0
0.00
Offsite
0
0.00
Parking
0
0.00
Misc
212,827
4.89
Total
212,827
4.89
WATERSHED BREAKDOWN
Contributing Area
SCS CN Area fsfl Area facl Comments
Impervious
212,827
4.89
Open
56
205,293
4.71
Assume good condition
Wooded
50
30,587
0.70
Assume good condition
Open Water
100
0
0.00
Total Area = 10.30 acres
0.0161 �sq mi
Composite SCS CN =� 76
% Impervious
TIME OF CONCENTRATION
(REF: SCS TR-55).
Time of Concentration = 5.00 min

PILOT
a.............
Project Name: Pfafftown Self Storage
Project Number: 22-245
Subbasin ID: DA1- BYP
SCS CURVE NUMBERS
(REF: SCS TR-55)
HYDROLOGIC CALCULATIONS
Date: 12/14/2022
Calculated By: JCG
HSG
Impervious
Open
Wooded
Pond
A
98
39
30
100
B
98
61
55
100
C
98
74
70
100
D
98
80
77
100
HSG A =
HSG B =
HSG C =
MO%
HSG D =
Cover Condition SCS CN Comments
Impervious
98
1 -
Open
61
Assume good condition
Wooded
55
Assume good condition
Pond
100
OFF SITE IMPERVIOUS BREAKDOWN
Contributing Area Area [sf] Area [ac]
Building
0
0.06
Offsite
0
0.00
Parking
0
0.00
Misc
2,768
0.06
Total
2,768
0.06
WATERSHED BREAKDOWN
Contributing Area SCS CN Area [sf] Area [ac] Comments
Impervious
98
2,768
0.06
1 -
Open
61
8,951
0.21
Assume good condition
Wooded
55
51,951
1.19
Assume good condition
Open Water
100
0
0.00
Total Area = 1.46 acres
= 0.0023 sq mi
Composite SCS CN = 58
% Impervious = 4.35%

TIME OF CONCENTRATION
(REF: SCS TR-55).
Length =
Upstream Invert=
Downstream Invert=
Slope =
Manning's n =
P (2-year/24-hour) =
Segment Time =
100
934.50
926.00
0.0850
0.24
3.43
7.73
ft
ft
ft
ft/ft
dense
inche<
min
ft
ft
ft
ft/ft
ft/sec
min
egment 2: Concentrated Flow
Length =
Upstream Invert=
Downstream Invert=
Slope =
Paved? =
Velocity =
Segment Time =
134
926.00
902.00
0.1791
No
6.83
0.33
Length =
Upstream Invert =
Downstream Invert =
Slope =
Manning's n =
Flow Area =
Wetted Perimeter =
Channel Velocity =
Segment Time =1
298
ft (REF: Natural Channel Design Handbook)
ft Design criteria for stabilized channel
ft is 3.5-6 ft/sec
ft/ft Assumed Bottom Width= 1 4.00 ft
natural channel Assumed Depth= 1.50 ft
ft
ft
ft
Imin
902.00
893.00
0.0302
0.045
6.00
7.00
5.19
0.96
Time of Concentration = 9.01 min

Project Name: Pfafftown Self Storage
Project Number: 22-245
Subbasin ID: DA2 - BYP
SCS CURVE NUMBERS
HYDROLOGIC CALCULATIONS
Date: 12/14/2022
Calculated By: 1CG
(REF: SCS TR-55).
HSG
Impervious
Open
Wooded
Pond
A
98
39
30
100
B
98
61
55
100
C
98
74
70
100
D
98
80
77
100
HSG A= 5%
HSG B= 95%
HSG C= 0%
HSG D = 0%
Cover Condition SCS CN Comments
Impervious
98
Open
60
Assume good condition
Wooded
54
Assume good condition
Pond
100
OFF SITE IMPERVIOUS BREAKDOWN
Contributing Area Area [sf] Area [ac]
Building
0
0.00
Offsite
0
0.00
Parking
0
0.00
Misc
5,526
0.13
Total
5,526
0.13
WATERSHED BREAKDOWN
Contributing Area SCS CN Area [sf] Area [ac] Comments
Impervious
98
5,526
0.13
Open
60
52,950
1.22
Assume good condition
Wooded
54
0
0.00
Assume good condition
Open Water
100
0
0.00
Total Area = 1.34 acres
= 0.0021 sq mi
Composite SCS CN = 64
% Impervious =
TIME OF CONCENTRATION
REF: SCS TR-55 .
Segment 1: Overland Flow
Length =
100
ft
Upstream Invert=
949.00
ft
Downstream Invert =
946.50
ft
Slope =
0.0250
ft/ft
Manning's n =
0.01
gravel & bare soil
P (2-year/24-hour) =
3.43
inches (Pfafftown, NCJ
Segment Time=
1.07
min
Segment 2: Concentrated Flow
Length = 85
Upstream Invert= 946.50
Downstream Invert = 943.00
Slope = 0.0412
Paved? = No
Velocity = 3.27
Segment Time = 0.43
ft
ft
ft
ft/ft
min
Time of Concentration = 5.00 min

Detention
Summary &
Water Quality
Calculations
Page 6 of 13

STORMWATER MANAGEMENT CALCUATIONS
For: COC Investments, LLC
2049 West Pine Street
Mount Airy, NC 27030
Pfafftown Self Storage
PILOT
SURVEYING & ENGINEERING
Project Number: 22-271
By: Cory George, PE, PLS
106 S. Depot Street
Suite D
Pilot Mountain, NC 27041

Detention Summary
Project Name: Pfafftown Self Storage
roject Number: 22-271
Detention Summary
Date: 12/15/2022
Calculated By: JCG
Point of 1 2 Year Storm [cfs] 10 Year Storm [cfs] 25 Year Storm [cfs]
Analvsis Pre Post % Incr. Pre I Post I % Incr. Pre I Post I % Incr.
1
1 5.59
1 2.69
1 -52%
1 18.89
1 14.34
1 -24%
1 28.71
1 26.41
1 -8%
2
1 1.63
1 1.51
1 -7%
1 5.16
1 3.99
1 -23%
1 7.76
1 5.74
1 -26%
Detention Summary - 1 Year 24 Hour Storm
Point of 1 Year Storm [cfs]
Analysis Pre Post % Incr.
1 2.20 0.66 -70%
SCM Summary
Drainage Area =
10.30
ac
Impervious Area =
4.89
ac
% Impervious
47%
Top of Dam =
915.00
ft
Normal Pool =1
909.00 Ift
Riser Size =
4'x4'
Riser Crest =1
912.50 Ift
Em. Spillway Crest =
913.50
ft
Em. Spillway Width =1
15.00 Ift
Barrel Diameter =
24
in
# of Barrells =
1
Invert In =
905.00
ft
Invert Out =
904.00
ft
Length =
78
ft
Slope =
1.3%
Routing Summary
Return Inflow Outflow Max Freeboard
Period cfs cfs WSE ft
2
25.23
2.54
910.79
4.21
10
49.12
12.33
912.01
2.99
25
64.63
23.35
912.77
2.23
100
91.38
45.88
913.63
1.37

Forebay Stage Storage
Project Name: Pfafftown Self Storage
Project Number: 22-271
Stage - Storage Function - Forebay
Contour
Contour Stage Area
(feet) (feet) (SF)
Date: 12/14/2022
Calculated By: JCG
Average
Incremental
Accumulated
Estimated
Contour
Contour
Contour
Stage
Area
Volume
Volume
w/ S-S Fxn
(SF)
(CF)
(CF)
(feet)
904.00
0.00
216
906.00
2.00
1000
608
1216
1216
2.01
907.00
3.00
1435
1218
1218
2434
2.97
908.00
4.00
1895
1665
1665
4099
3.98
909.00
5.00
2409
2152
2152
6251
5.04
Storage vs. Stage
7000
6000
y = 348.98x1.7836
5000
RZ = 0.9994
LL
4000
v
1
`o
3000
Y
`^
2000
1000
0
1.00 2.00 3.00 4.00 5.00 6.00
0.00
Stage (feet)
KS -1 349
b - 1.7836

Main Pool Volume
Project Name: Pfafftown Self Storage
Project Number: 22-271
Stage - Storage Function - Main Pool
Contour
Contour Stage Area
(feet) (feet) (SF)
Average
Incremental
Contour
Contour
Area
Volume
(SF)
(CF)
Date: 12/14/2022
Calculated By: JCG
Accumulated
Estimated
Contour
Stage
Volume
w/ S-S Fxn
(CF)
(feet)
901.00
0.00
2073
904.00
3.00
3810
2942
8825
8825
3.05
905.00
4.00
4464
4137
4137
12962
3.97
906.00
5.00
5163
4814
4814
17775
4.93
907.00
6.00
5898
5531
5531
23306
5.93
908.00
7.00
6657
6278
6278
29583
6.98
909.00
8.00
8606
7632
1 7632
1 37215
1 8.17
Storage vs. Stage
40000
35000
y = 1730.1x1.461
30000
RZ = 0.9978
U
25000
20000
aio
�o
0
15000
i+
10000
5000
0
0.00
2.00 4.00 6.00 8.00 10.00
Stage (feet)
KS —1 1730
b=1 1.4610

Total Stage Storage
Project Name: Pfafftown Self Storage
Project Number: 22-271
SCM ID: WP-1
Stage - Storage Function - Total Above NP
Contour
Contour Stage Area
(feet) (feet) (SF)
Date: 12/14/2022
Calculated By: JCG
Average
Incremental
Accumulated
Estimated
Contour
Contour
Contour
Stage
Area
Volume
Volume
w/ S-S Fxn
(SF)
(CF)
(CF)
(feet)
909.00
0.00
11669
910.00
1.00
13056
12363
12363
12363
1.01
912.00
3.00
16002
14529
29058
41421
2.94
913.00
4.00
17559
16781
16781
58201
3.98
914.00
5.00
19173
18366
18366
76567
5.08
915.00
1 6.00
1 20841
1 20007
20007
96574
6.25
Storage vs. Stage
120000
100000
y = 12184x1.14
LL
80000
RZ = 0.9985
60000
ajo
�o
N
40000
20000
0
0.00
1.00 2.00 3.00 4.00 5.00 6.00 7.00
Stage (feet)
KS -1 12273
b - 1.1262

Main Pool Surface Area and Volume Calculc-
Project Name: Pfafftown Self Storage Date: #########
Project Number: 22-271 Calculated By: JCG
Determination of Design Volume
DV = 3,630*(R p)*(R v)*(A)
where,
DV = design volume (cubic feet)
R v = 0.05+0.009(1) where 1 is percent impervious cover
A = area in acres
R p = design storm depth (in inches)
Total area, A =
10.30
acres
Impervious area =
4.89
acres
Percent impervious cover, I =
47.48
Design Storm Depth, Rp =
1.00
inches
R`, =
0.48
DV=J
17,845
cf.
Forebay Volume Calculation
Forebay Volume = M7,215
cf
MainPool Volume = cf
VFB Of VMP = 15-20% Required

SA/DA Table Method
Vol. of Main Pool @ NSE, Vpp = 37,215 cf.
SA of Main Pool @ NSE, SA = 8,606 cf.
Average Depth, Dag = 4.32 ft
4.00
4.32 5.00
Low Bound
40% 1.24
1.09
Site Impervious
47% 1.44
1.38 1.25
High Bound
50% 1.51
1.31
SA/DA Ratio Required = 1.38
Drainage Area, A
Main Pool Surface Area Required = 0.14 ac
6,196 sf
Main Pool Surface Area Provided = 8,606 sf
Table 1: Piedmont and Mountain SA/DA Table (Adapted from Driscoll, 1986)
Percent
Impervious Cover
Permanet Pool Average Depth (ft)
3.0
4.0
5.0
6.0
7.0
>_ 8.0
10%
0.51
0.43
0.37
0.30
0.27
0.25
20%
0.84
0.69
0.61
0.51
0.44
0.40
30%
1.17
0.94
0.84
0.72
0.61
0.56
40 %
1.51
1.24
1.09
0.91
0.78
0.71
50%
1.79
1.51
1.31
1.13
0.95
0.87
60%
2.09
1.77
1.49
1.31
1.12
1.03
70%
2.51
2.09
1.80
1.56
1.34
1.17
80%
2.92
2.41
2.07
1.82
1.62
1.40
90%
3.25
2.64
2.31
2.04
1.84
1.59
100%
3.55
2.79
2.52
2.34
2.04
1.75

Design Volume Depth
DV = 17,845
Ks = 12273
b= 1.13
Depth of DV in Pond = 1.39 ft
Normal Pool Elevation = 909.00
Elevation of DV = 910.39
Drawdown Calcuation (Average Head)
Orifice Diameter, D = 2 in
No. of Orifices = 1
Depth of DV in Pond = 1.39 ft
Average Head on Orifice = 0.66 ft
Orifice Coefficient = 0.6
Area of Orifice = 0.022 sf
Average Flow Rate = 0.085 cfs
Drawdown Time = 2.43 days

Hydrographs
Modeling Report
Page 7 of 13

Hy d raf I ow Table of C o nteenf\2022\22-271 - Joe Dobbin - Pfafftown Storage\Design\Hydrographs\Wet_Pond2.gpw
Hydraflow Hydrographs Extension for AUtodeskS Civil 3DO by Autodesk, Inc. v2022
Wednesday, 12 / 14 / 2022
2 - Year
SummaryReport.........................................................................................................................
1
HydrographReports
...................................................................................................................
2
Hydrograph No.
1, SCS Runoff, Pre - DA#1............................................................................
2
Hydrograph No.
2, SCS Runoff, Pre - DA#2............................................................................
3
Hydrograph No.
3, SCS Runoff, Post - DA#1 to SCM..............................................................
4
Hydrograph No.
4, SCS Runoff, Post - DA#1 BYP..................................................................
5
Hydrograph No.
5, SCS Runoff, Post - DA#2 BYP..................................................................
6
Hydrograph No.
6, Reservoir, SCM Routing............................................................................
7
PondReport
- SCM.............................................................................................................
8
Hydrograph No.
7, Combine, Post - POA#1.............................................................................
9
10 -Year
SummaryReport
.......................................................................................................................
10
HydrographReports.................................................................................................................
11
Hydrograph No.
1, SCS Runoff, Pre - DA#1..........................................................................
11
Hydrograph No.
2, SCS Runoff, Pre - DA#2..........................................................................
12
Hydrograph No.
3, SCS Runoff, Post - DA#1 to SCM............................................................
13
Hydrograph No.
4, SCS Runoff, Post - DA#1 BYP................................................................
14
Hydrograph No.
5, SCS Runoff, Post - DA#2 BYP................................................................
15
Hydrograph No.
6, Reservoir, SCM Routing..........................................................................
16
Hydrograph No.
7, Combine, Post - POA#1...........................................................................
17
25 - Year
SummaryReport
.......................................................................................................................
18
HydrographReports.................................................................................................................
19
Hydrograph No.
1, SCS Runoff, Pre - DA#1..........................................................................
19
Hydrograph No.
2, SCS Runoff, Pre - DA#2..........................................................................
20
Hydrograph No.
3, SCS Runoff, Post - DA#1 to SCM............................................................
21
Hydrograph No.
4, SCS Runoff, Post - DA#1 BYP................................................................
22
Hydrograph No.
5, SCS Runoff, Post - DA#2 BYP................................................................
23
Hydrograph No.
6, Reservoir, SCM Routing..........................................................................
24
Hydrograph No.
7, Combine, Post - POA#1...........................................................................
25
100 - Year
SummaryReport
.......................................................................................................................
26
HydrographReports.................................................................................................................
27
Hydrograph No.
1, SCS Runoff, Pre - DA#1..........................................................................
27
Hydrograph No.
2, SCS Runoff, Pre - DA#2..........................................................................
28
Hydrograph No.
3, SCS Runoff, Post - DA#1 to SCM............................................................
29
Hydrograph No.
4, SCS Runoff, Post - DA#1 BYP................................................................
30
Hydrograph No.
5, SCS Runoff, Post - DA#2 BYP................................................................
31
Hydrograph No.
6, Reservoir, SCM Routing..........................................................................
32
Hydrograph No.
7, Combine, Post - POA#1...........................................................................
33

Hydrograph Summary Report
Hydraflow Hydrographs Extension for Autodesk@ Civil 3DO by Autodesk, Inc. v2022
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
5.587
1
723
19,197
------
------
------
Pre - DA#1
2
SCS Runoff
1.629
1
719
4,037
------
------
------
Pre - DA#2
3
SCS Runoff
25.23
1
718
50,694
------
------
------
Post - DA#1 to SCM
4
SCS Runoff
0.688
1
721
2,256
------
------
------
Post - DA#1 BYP
5
SCS Runoff
1.512
1
718
3,361
------
------
------
Post - DA#2 BYP
6
Reservoir
2.542
1
747
40,500
3
910.79
23,239
SCM Routing
7
Combine
2.688
1
746
42,756
4,6
------
------
Post - POA#1
P:\Projects\2022\22-271 - Joe Dobbin - Pfaf
obdetBtnr1RgeQeQ0hkydrographs
gW&WXay;,p1.2 / 14 / 2022

Hydrograph Report
2
Hydraflow Hydrographs Extension for AUtodeskS Civil 3DO by Autodesk, Inc. v2022
Hyd. No. 1
Pre - DA#1
Hydrograph type
= SCS Runoff
Storm frequency
= 2 yrs
Time interval
= 1 min
Drainage area
= 10.710 ac
Basin Slope
= 0.0 %
Tc method
= User
Total precip.
= 3.43 in
Storm duration
= 24 hrs
Q (cfs)
6.00
5.00
4.00
3.00
2.00
1.00
Peak discharge
Time to peak
Hyd. volume
Curve number
Hydraulic length
Time of conc. (Tc)
Distribution
Shape factor
Pre - DA#1
Hyd. No. 1 -- 2 Year
0 120 240 360 480 600 720
— Hyd No. 1
840
Wednesday, 12 / 14 / 2022
= 5.587 cfs
= 723 min
= 19,197 cuft
= 60
= 0 ft
= 12.00 min
= Type II
= 484
Q (cfs)
6.00
5.00
4.00
3.00
2.00
1.00
' 0.00
960 1080 1200 1320 1440 1560
Time (min)

Hydrograph Report
K
Hydraflow Hydrographs Extension for AUtodeskS Civil 3DO by Autodesk, Inc. v2022
Hyd. No. 2
Pre - DA#2
Hydrograph type
= SCS Runoff
Storm frequency
= 2 yrs
Time interval
= 1 min
Drainage area
= 2.150 ac
Basin Slope
= 0.0 %
Tc method
= User
Total precip.
= 3.43 in
Storm duration
= 24 hrs
Q (cfs)
2.00
1.00
Peak discharge
Time to peak
Hyd. volume
Curve number
Hydraulic length
Time of conc. (Tc)
Distribution
Shape factor
Pre - DA#2
Hyd. No. 2 -- 2 Year
120 240 360 480 600 720 840 960
Hyd No. 2
Wednesday, 12 / 14 / 2022
= 1.629 cfs
= 719 min
= 4,037 cuft
= 60
= 0 ft
= 5.00 min
= Type II
= 484
Q (cfs)
2.00
1.00
0.00
1080 1200 1320 1440 1560
Time (min)

4
Hydrograph Report
Hydraflow Hydrographs Extension for AUtodeskS Civil 3DO by Autodesk, Inc. v2022
Wednesday, 12 / 14 / 2022
Hyd. No. 3
Post - DA#1 to SCM
Hydrograph type
= SCS Runoff
Peak discharge
= 25.23 cfs
Storm frequency
= 2 yrs
Time to peak
= 718 min
Time interval
= 1 min
Hyd. volume
= 50,694 cuft
Drainage area
= 10.300 ac
Curve number
= 76
Basin Slope
= 0.0 %
Hydraulic length
= 0 ft
Tc method
= User
Time of conc. (Tc)
= 5.00 min
Total precip.
= 3.43 in
Distribution
= Type II
Storm duration
= 24 hrs
Shape factor
= 484
Q (cfs)
28.00
24.00
16.00
12.00
4.00
Post - DA#1 to SCM
Hyd. No. 3 -- 2 Year
Q (cfs)
28.00
24.00
20.00
16.00
12.00
4.00
0.00 - 0.00
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
— Hyd No. 3 Time (min)

I-
Hydrograph Report
Hydraflow Hydrographs Extension for AUtodeskS Civil 3DO by Autodesk, Inc. v2022
Wednesday, 12 / 14 / 2022
Hyd. No. 4
Post - DA#1 BYP
Hydrograph type
= SCS Runoff
Peak discharge
= 0.688 cfs
Storm frequency
= 2 yrs
Time to peak
= 721 min
Time interval
= 1 min
Hyd. volume
= 2,256 cuft
Drainage area
= 1.460 ac
Curve number
= 58
Basin Slope
= 0.0 %
Hydraulic length
= 0 ft
Tc method
= User
Time of conc. (Tc)
= 9.00 min
Total precip.
= 3.43 in
Distribution
= Type II
Storm duration
= 24 hrs
Shape factor
= 484
Q (cfs)
1.00
0.90
WE
0.70
0.60
0.50
0.40
0.30
0.20
0.10
0.00
0
Post - DA#1 BYP
Hyd. No. 4 -- 2 Year
Q (cfs)
1.00
0.90
M :M
0.70
0.60
0.50
0.40
0.30
0.20
0.10
0.00
120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Hyd No. 4 Time (min)

Hydrograph Report
Hydraflow Hydrographs Extension for AUtodeskS Civil 3DO by Autodesk, Inc. v2022
Hyd. No. 5
Post - DA#2 BYP
Hydrograph type
= SCS Runoff
Storm frequency
= 2 yrs
Time interval
= 1 min
Drainage area
= 1.340 ac
Basin Slope
= 0.0 %
Tc method
= User
Total precip.
= 3.43 in
Storm duration
= 24 hrs
Q (cfs)
2.00
1.00
Peak discharge
Time to peak
Hyd. volume
Curve number
Hydraulic length
Time of conc. (Tc)
Distribution
Shape factor
Post - DA#2 BYP
Hyd. No. 5 -- 2 Year
120 240 360 480 600 720 840 960
Hyd No. 5
Wednesday, 12 / 14 / 2022
= 1.512 cfs
= 718 min
= 3,361 cuft
= 64
= 0 ft
= 5.00 min
= Type II
= 484
Q (cfs)
2.00
1.00
0.00
1080 1200 1320 1440 1560
Time (min)

Hydrograph Report
I
U
Hydraflow Hydrographs Extension for AUtodeskS Civil 3DO by Autodesk, Inc. v2022
Hyd. No. 6
SCM Routing
Hydrograph type
= Reservoir
Storm frequency
= 2 yrs
Time interval
= 1 min
Inflow hyd. No.
= 3 - Post - DA#1 to SCM
Reservoir name
= SCM
Storage Indication method used.
Q (cfs)
28.00
24.00
16.00
12.00
4.00
Peak discharge
Time to peak
Hyd. volume
Max. Elevation
Max. Storage
SCM Routing
Hyd. No. 6 -- 2 Year
Wednesday, 12 / 14 / 2022
= 2.542 cfs
= 747 min
= 40,500 cuft
= 910.79 ft
= 23,239 cuft
Q (cfs)
28.00
24.00
20.00
16.00
12.00
4.00
0.00 ' 1' � ' ' 0.00
0 300 600 900 1200 1500 1800 2100 2400 2700 3000
Time (min)
— Hyd No. 6 — Hyd No. 3 ® Total storage used = 23,239 cult

Pond Report $
Hydraflow Hydrographs Extension for Autodesk@ Civil 3D@ by Autodesk, Inc. v2022 Wednesday, 12 / 14 / 2022
Pond No. 1 - SCM
Pond Data
Contours -User-defined contour areas. Conic method used for volume calculation. Begining Elevation = 909.00 ft
Stage / Storage Table
Stage (ft) Elevation (ft) Contour area (sqft) Incr. Storage (cuft) Total storage (cuft)
0.00
909.00
11,669
0
0
1.00
910.00
13,056
12,355
12,355
2.00
911.00
14,501
13,771
26,126
3.00
912.00
16,002
15,244
41,369
4.00
913.00
17,559
16,773
58,142
5.00
914.00
19,172
18,358
76,500
6.00
915.00
20,841
19,999
96,499
Culvert / Orifice Structures
Weir Structures
[A]
[B]
[C]
[PrFRsr]
[A]
[B]
[C]
[D]
Rise (in)
= 24.00
2.00
6.00
0.00
Crest Len (ft)
= 16.00
15.00
0.00
0.00
Span (in)
= 24.00
2.00
18.00
0.00
Crest El. (ft)
= 912.50
913.50
0.00
0.00
No. Barrels
= 1
1
3
0
WeirCoeff.
= 3.33
2.60
3.33
3.33
Invert El. (ft)
= 904.00
909.00
910.50
0.00
Weir Type
= 1
Broad
---
---
Length (ft)
= 78.00
0.00
0.00
0.00
Multi -Stage
= Yes
No
No
No
Slope (%)
= 1.50
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)
= 0.000 (by
Contour)
Multi -Stage
= n/a
Yes
Yes
No
TW Elev. (ft)
= 0.00
Note: Culvert/Orifice outflows are analyzed under inlet (ic) and outlet (oc) control. Weir risers checked for orifice conditions (ic) and submergence (s).
Stage /
Storage / Discharge Table
Stage
Storage
Elevation
CIvA
CIvB
CIvC PrfRsr
WrA
WrB WrC
WrD ExfiI User Total
ft
cuft
ft
cfs
cfs
cfs cfs
cfs
cfs cfs
cfs cfs cfs cfs
0.00
0
909.00
0.00
0.00
0.00 ---
0.00
0.00 ---
--- --- --- 0.000
1.00
12,355
910.00
30.25 is
0.10 is
0.00 ---
0.00
0.00 ---
--- --- --- 0.101
2.00
26,126
911.00
30.25 is
0.15 is
5.42 is ---
0.00
0.00 ---
--- --- --- 5.562
3.00
41,369
912.00
30.25 is
0.18 is
12.11 is ---
0.00
0.00 ---
--- --- --- 12.29
4.00
58,142
913.00
35.26 is
0.17 is
16.25 is ---
18.84
0.00 ---
--- --- --- 35.26
5.00
76,500
914.00
45.10 is
0.03 is
3.59 is ---
41.47 s
13.79 ---
--- --- --- 58.88
6.00
96,499
915.00
47.75 is
0.02 is
1.93 is ---
45.78 s
71.65 ---
--- --- --- 119.38

Hydrograph
Report
9
Hydraflow Hydrographs Extension for AUtodeskS Civil 3DO by Autodesk, Inc. v2022
Wednesday, 12 / 14 / 2022
Hyd. No. 7
Post - POA#1
Hydrograph type
= Combine
Peak discharge
= 2.688 cfs
Storm frequency
= 2 yrs
Time to peak
= 746 min
Time interval
= 1 min
Hyd. volume
= 42,756 cuft
Inflow hyds.
= 4, 6
Contrib. drain. area
= 1.460 ac
Q (cfs)
3.00
2.00
1.00
e
Post - POA#1
Hyd. No. 7 -- 2 Year
Q (cfs)
3.00
2.00
1.00
I J I ----L I I I 1
0.00
300 600 900 1200 1500 1800 2100 2400 2700 3000
Time (min)
Hyd No. 7 Hyd No. 4 Hyd No. 6

Hydrograph Summary Report
10
Hydraflow Hydrographs Extension for Autodesk@ Civil 3DO by Autodesk, Inc. v2022
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
18.86
1
722
50,913
------
------
------
Pre - DA#1
2
SCS Runoff
5.161
1
718
10,707
------
------
------
Pre - DA#2
3
SCS Runoff
49.12
1
718
99,354
------
------
------
Post - DA#1 to SCM
4
SCS Runoff
2.617
1
720
6,341
------
------
------
Post - DA#1 BYP
5
SCS Runoff
3.989
1
718
8,092
------
------
------
Post - DA#2 BYP
6
Reservoir
12.33
1
726
89,024
3
912.01
41,512
SCM Routing
7
Combine
14.34
1
723
95,365
4,6
------
------
Post - POA#1
P:\Projects\2022\22-271 - Joe Dobbin - Pfaf
obdetBtnfflgdQedigr)Kk#drographs
gW&WXay;,p1.2 / 14 / 2022

Hydrograph Report
Hydraflow Hydrographs Extension for AUtodeskS Civil 3DO by Autodesk, Inc. v2022
Wednesday, 12 / 14 / 2022
Hyd. No. 1
Pre - DA#1
Hydrograph type
= SCS Runoff
Peak discharge
= 18.86 cfs
Storm frequency
= 10 yrs
Time to peak
= 722 min
Time interval
= 1 min
Hyd. volume
= 50,913 cuft
Drainage area
= 10.710 ac
Curve number
= 60
Basin Slope
= 0.0 %
Hydraulic length
= 0 ft
Tc method
= User
Time of conc. (Tc)
= 12.00 min
Total precip.
= 5.05 in
Distribution
= Type II
Storm duration
= 24 hrs
Shape factor
= 484
Q (cfs)
21.00
18.00
15.00
12.00
• Me
3.00
Pre - DA#1
Hyd. No. 1 -- 10 Year
Q (cfs)
21.00
18.00
15.00
12.00
• rs
3.00
0.00 10.00
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
— Hyd No. 1 Time (min)

Hydrograph Report
12
Hydraflow Hydrographs Extension for AUtodeskS Civil 3DO by Autodesk, Inc. v2022
Hyd. No. 2
Pre - DA#2
Hydrograph type
= SCS Runoff
Storm frequency
= 10 yrs
Time interval
= 1 min
Drainage area
= 2.150 ac
Basin Slope
= 0.0 %
Tc method
= User
Total precip.
= 5.05 in
Storm duration
= 24 hrs
Q (cfs)
6.00
5.00
4.00
3.00
2.00
1.00
Peak discharge
Time to peak
Hyd. volume
Curve number
Hydraulic length
Time of conc. (Tc)
Distribution
Shape factor
Pre - DA#2
Hyd. No. 2 -- 10 Year
0.00 ' ' ' ' 1 'N L
0 120 240 360 480 600 720
— Hyd No. 2
840
Wednesday, 12 / 14 / 2022
= 5.161 cfs
= 718 min
= 10,707 cuft
= 60
= 0 ft
= 5.00 min
= Type II
= 484
Q (cfs)
6.00
5.00
4.00
3.00
2.00
1.00
0.00
960 1080 1200 1320 1440 1560
Time (min)

Hydrograph
Report
13
Hydraflow Hydrographs Extension for AUtodeskS Civil 3DO by Autodesk, Inc. v2022
Wednesday, 12 / 14 / 2022
Hyd. No. 3
Post - DA#1 to SCM
Hydrograph type
= SCS Runoff
Peak discharge
= 49.12 cfs
Storm frequency
= 10 yrs
Time to peak
= 718 min
Time interval
= 1 min
Hyd. volume
= 99,354 cuft
Drainage area
= 10.300 ac
Curve number
= 76
Basin Slope
= 0.0 %
Hydraulic length
= 0 ft
Tc method
= User
Time of conc. (Tc)
= 5.00 min
Total precip.
= 5.05 in
Distribution
= Type II
Storm duration
= 24 hrs
Shape factor
= 484
Post - DA#1 to 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
0.00 - 0.00
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
— Hyd No. 3 Time (min)

Hydrograph
Report
14
Hydraflow Hydrographs Extension for AUtodeskS Civil 3DO by Autodesk, Inc. v2022
Wednesday, 12 / 14 / 2022
Hyd. No. 4
Post - DA#1 BYP
Hydrograph type
= SCS Runoff
Peak discharge
= 2.617 cfs
Storm frequency
= 10 yrs
Time to peak
= 720 min
Time interval
= 1 min
Hyd. volume
= 6,341 cuft
Drainage area
= 1.460 ac
Curve number
= 58
Basin Slope
= 0.0 %
Hydraulic length
= 0 ft
Tc method
= User
Time of conc. (Tc)
= 9.00 min
Total precip.
= 5.05 in
Distribution
= Type II
Storm duration
= 24 hrs
Shape factor
= 484
Post - DA#1 BYP
Q (cfs) Hyd. No. 4 -- 10 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. 4 Time (min)

Hydrograph
Report
15
Hydraflow Hydrographs Extension for AUtodeskS Civil 3DO by Autodesk, Inc. v2022
Wednesday, 12 / 14 / 2022
Hyd. No. 5
Post - DA#2 BYP
Hydrograph type
= SCS Runoff
Peak discharge
= 3.989 cfs
Storm frequency
= 10 yrs
Time to peak
= 718 min
Time interval
= 1 min
Hyd. volume
= 8,092 cuft
Drainage area
= 1.340 ac
Curve number
= 64
Basin Slope
= 0.0 %
Hydraulic length
= 0 ft
Tc method
= User
Time of conc. (Tc)
= 5.00 min
Total precip.
= 5.05 in
Distribution
= Type II
Storm duration
= 24 hrs
Shape factor
= 484
Post - DA#2 BYP
Q (cfs) Hyd. No. 5 -- 10 Year Q (cfs)
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. 5 Time (min)

16
Hydrograph Report
Hydraflow Hydrographs Extension for AUtodeskS Civil 3DO by Autodesk, Inc. v2022
Wednesday, 12 / 14 / 2022
Hyd. No. 6
SCM Routing
Hydrograph type
= Reservoir
Peak discharge
= 12.33 cfs
Storm frequency
= 10 yrs
Time to peak
= 726 min
Time interval
= 1 min
Hyd. volume
= 89,024 cuft
Inflow hyd. No.
= 3 - Post - DA#1 to SCM
Max. Elevation
= 912.01 ft
Reservoir name
= SCM
Max. Storage
= 41,512 cuft
Storage Indication method used.
SCM Routing
Q (cfs) Hyd. No. 6 -- 10 Year Q (cfs)
50.00 50.00
40.00 40.00
30.00 30.00
20.00 20.00
10.00 10.00
0.00 0.00
0 180 360 540 720 900 1080 1260 1440 1620
Time (min)
— Hyd No. 6 Hyd No. 3 ® Total storage used = 41,512 cult

Hydrograph
Report
17
Hydraflow Hydrographs Extension for AUtodeskS Civil 3DO by Autodesk, Inc. v2022
Wednesday, 12 / 14 / 2022
Hyd. No. 7
Post - POA#1
Hydrograph type
= Combine
Peak discharge
= 14.34 cfs
Storm frequency
= 10 yrs
Time to peak
= 723 min
Time interval
= 1 min
Hyd. volume
= 95,365 cuft
Inflow hyds.
= 4, 6
Contrib. drain. area
= 1.460 ac
Post - POA#1
Q (cfs) Hyd. No. 7 -- 10 Year Q (cfs)
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
Time (min)
— Hyd No. 7 Hyd No. 4 Hyd No. 6

Hydrograph Summary Report
18
Hydraflow Hydrographs Extension for Autodesk@ Civil 3DO by Autodesk, Inc. v2022
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
28.71
1
722
74,792
------
------
------
Pre - DA#1
2
SCS Runoff
7.761
1
718
15,729
------
------
------
Pre - DA#2
3
SCS Runoff
64.63
1
718
131,993
------
------
------
Post - DA#1 to SCM
4
SCS Runoff
4.077
1
720
9,476
------
------
------
Post - DA#1 BYP
5
SCS Runoff
5.738
1
718
11,533
------
------
------
Post - DA#2 BYP
6
Reservoir
23.35
1
724
121,612
3
912.77
54,361
SCM Routing
7
Combine
26.41
1
724
131,088
4,6
------
------
Post - POA#1
P:\Projects\2022\22-271 - Joe Dobbin - Pfaf
obdetBtnrlRgeQe!i§r)Kk#drographs
gW&WXay;,p1.2 / 14 / 2022

Hydrograph Report
19
Hydraflow Hydrographs Extension for AUtodeskS Civil 3DO by Autodesk, Inc. v2022
Hyd. No. 1
Pre - DA#1
Hydrograph type
= SCS Runoff
Storm frequency
= 25 yrs
Time interval
= 1 min
Drainage area
= 10.710 ac
Basin Slope
= 0.0 %
Tc method
= User
Total precip.
= 6.05 in
Storm duration
= 24 hrs
Q (cfs)
30.00
25.00
15.00
10.00
5.00
Peak discharge
Time to peak
Hyd. volume
Curve number
Hydraulic length
Time of conc. (Tc)
Distribution
Shape factor
Pre - DA#1
Hyd. No. 1 -- 25 Year
0.00 ' 1 1 1�--r I
0 120 240 360 480 600 720
— Hyd No. 1
840
Wednesday, 12 / 14 / 2022
= 28.71 cfs
= 722 min
= 74,792 cuft
= 60
= 0 ft
= 12.00 min
= Type II
= 484
Q (cfs)
30.00
25.00
20.00
15.00
10.00
5.00
_ —1 0.00
960 1080 1200 1320 1440 1560
Time (min)

Hydrograph Report
20
Hydraflow Hydrographs Extension for AUtodeskS Civil 3DO by Autodesk, Inc. v2022
Hyd. No. 2
Pre - DA#2
Hydrograph type
= SCS Runoff
Storm frequency
= 25 yrs
Time interval
= 1 min
Drainage area
= 2.150 ac
Basin Slope
= 0.0 %
Tc method
= User
Total precip.
= 6.05 in
Storm duration
= 24 hrs
Q (cfs)
8.00
M
4.00
2.00
0.00
0 120 240 360 480 600 720
— Hyd No. 2
Peak discharge
Time to peak
Hyd. volume
Curve number
Hydraulic length
Time of conc. (Tc)
Distribution
Shape factor
Pre - DA#2
Hyd. No. 2 -- 25 Year
840
Wednesday, 12 / 14 / 2022
= 7.761 cfs
= 718 min
= 15,729 cuft
= 60
= 0 ft
= 5.00 min
= Type II
= 484
Q (cfs)
8.00
M
4.00
r M�
0.00
960 1080 1200 1320 1440 1560
Time (min)

21
Hydrograph Report
Hydraflow Hydrographs Extension for AUtodeskS Civil 3DO by Autodesk, Inc. v2022
Wednesday, 12 / 14 / 2022
Hyd. No. 3
Post - DA#1 to SCM
Hydrograph type
= SCS Runoff
Peak discharge
= 64.63 cfs
Storm frequency
= 25 yrs
Time to peak
= 718 min
Time interval
= 1 min
Hyd. volume
= 131,993 cuft
Drainage area
= 10.300 ac
Curve number
= 76
Basin Slope
= 0.0 %
Hydraulic length
= 0 ft
Tc method
= User
Time of conc. (Tc)
= 5.00 min
Total precip.
= 6.05 in
Distribution
= Type II
Storm duration
= 24 hrs
Shape factor
= 484
Q (cfs)
70.00
50.00
40.00
30.00
10.00
Q (cfs)
70.00
•1 01
50.00
40.00
30.00
20.00
10.00
0.00 0.00
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440
— Hyd No. 3 Time (min)

Hydrograph
Report
22
Hydraflow Hydrographs Extension for AUtodeskS Civil 3DO by Autodesk, Inc. v2022
Wednesday, 12 / 14 / 2022
Hyd. No. 4
Post - DA#1 BYP
Hydrograph type
= SCS Runoff
Peak discharge
= 4.077 cfs
Storm frequency
= 25 yrs
Time to peak
= 720 min
Time interval
= 1 min
Hyd. volume
= 9,476 cuft
Drainage area
= 1.460 ac
Curve number
= 58
Basin Slope
= 0.0 %
Hydraulic length
= 0 ft
Tc method
= User
Time of conc. (Tc)
= 9.00 min
Total precip.
= 6.05 in
Distribution
= Type II
Storm duration
= 24 hrs
Shape factor
= 484
Post - DA#1 BYP
Q (cfs) Hyd. No. 4 -- 25 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. 4 Time (min)

Hydrograph Report
23
Hydraflow Hydrographs Extension for AUtodeskS Civil 3DO by Autodesk, Inc. v2022
Hyd. No. 5
Post - DA#2 BYP
Hydrograph type
= SCS Runoff
Storm frequency
= 25 yrs
Time interval
= 1 min
Drainage area
= 1.340 ac
Basin Slope
= 0.0 %
Tc method
= User
Total precip.
= 6.05 in
Storm duration
= 24 hrs
Q (cfs)
6.00
5.00
4.00
3.00
2.00
1.00
Peak discharge
Time to peak
Hyd. volume
Curve number
Hydraulic length
Time of conc. (Tc)
Distribution
Shape factor
Post - DA#2 BYP
Hyd. No. 5 -- 25 Year
0.00 ' 1 1 11 -
0 120 240 360 480 600 720
— Hyd No. 5
840
Wednesday, 12 / 14 / 2022
= 5.738 cfs
= 718 min
= 11, 533 cuft
= 64
= 0 ft
= 5.00 min
= Type II
= 484
Q (cfs)
6.00
5.00
4.00
3.00
2.00
1.00
0.00
960 1080 1200 1320 1440 1560
Time (min)

24
Hydrograph Report
Hydraflow Hydrographs Extension for AUtodeskS Civil 3DO by Autodesk, Inc. v2022
Wednesday, 12 / 14 / 2022
Hyd. No. 6
SCM Routing
Hydrograph type
= Reservoir
Peak discharge
= 23.35 cfs
Storm frequency
= 25 yrs
Time to peak
= 724 min
Time interval
= 1 min
Hyd. volume
= 121,612 cuft
Inflow hyd. No.
= 3 - Post - DA#1 to SCM
Max. Elevation
= 912.77 ft
Reservoir name
= SCM
Max. Storage
= 54,361 cuft
Storage Indication method used.
Q (cfs)
70.00
50.00
40.00
30.00
10.00
SCM Routing
Hyd. No. 6 -- 25 Year
Q (cfs)
70.00
*1 01
50.00
40.00
30.00
20.00
10.00
0.00 ' 1 1 1
' ' 0.00
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Time (min)
— Hyd No. 6 — Hyd No. 3 ® Total storage used = 54,361 cult

Hydrograph
Report
25
Hydraflow Hydrographs Extension for AUtodeskS Civil 3DO by Autodesk, Inc. v2022
Wednesday, 12 / 14 / 2022
Hyd. No. 7
Post - POA#1
Hydrograph type
= Combine
Peak discharge
= 26.41 cfs
Storm frequency
= 25 yrs
Time to peak
= 724 min
Time interval
= 1 min
Hyd. volume
= 131,088 cuft
Inflow hyds.
= 4, 6
Contrib. drain. area
= 1.460 ac
Post - POA#1
Q (cfs) Hyd. No. 7 -- 25 Year Q (cfs)
28.00 28.00
24.00 24.00
20.00 20.00
16.00 16.00
12.00 12.00
8.00 8.00
4.00 4.00
0.00 0.00
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Time (min)
— Hyd No. 7 — Hyd No. 4 Hyd No. 6

Hydrograph Summary Report
26
Hydraflow Hydrographs Extension for Autodesk@ Civil 3DO by Autodesk, Inc. v2022
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
47.05
1
721
119,870
------
------
------
Pre - DA#1
2
SCS Runoff
12.55
1
718
25,209
------
------
------
Pre - DA#2
3
SCS Runoff
91.38
1
717
189,426
------
------
------
Post - DA#1 to SCM
4
SCS Runoff
6.808
1
720
15,465
------
------
------
Post - DA#1 BYP
5
SCS Runoff
8.894
1
718
17,893
------
------
------
Post - DA#2 BYP
6
Reservoir
45.88
1
723
179,003
3
913.63
69,788
SCM Routing
7
Combine
51.74
1
722
194,468
4,6
------
------
Post - POA#1
P:\Projects\2022\22-271 - Joe Dobbin - Pfaf
obdetBtnr1RgeQediO6i\Y1ydrographs
gW&WXay;,p1.2 / 14 / 2022

Hydrograph Report
27
Hydraflow Hydrographs Extension for AUtodeskS Civil 3DO by Autodesk, Inc. v2022
Hyd. No. 1
Pre - DA#1
Hydrograph type
= SCS Runoff
Storm frequency
= 100 yrs
Time interval
= 1 min
Drainage area
= 10.710 ac
Basin Slope
= 0.0 %
Tc method
= User
Total precip.
= 7.73 in
Storm duration
= 24 hrs
Q (cfs)
50.00
40.00
30.00
10.00
Peak discharge
Time to peak
Hyd. volume
Curve number
Hydraulic length
Time of conc. (Tc)
Distribution
Shape factor
Pre - DA#1
Hyd. No. 1 -- 100 Year
0.00 i i i I - I I I I -
0 120 240 360 480 600 720
— Hyd No. 1
Wednesday, 12 / 14 / 2022
= 47.05 cfs
= 721 min
= 119,870 cuft
= 60
= 0 ft
= 12.00 min
= Type II
= 484
Q (cfs)
50.00
40.00
30.00
20.00
10.00
MWITil
840 960 1080 1200 1320 1440 1560
Time (min)

Hydrograph Report
28
Hydraflow Hydrographs Extension for AUtodeskS Civil 3DO by Autodesk, Inc. v2022
Hyd. No. 2
Pre - DA#2
Hydrograph type
= SCS Runoff
Storm frequency
= 100 yrs
Time interval
= 1 min
Drainage area
= 2.150 ac
Basin Slope
= 0.0 %
Tc method
= User
Total precip.
= 7.73 in
Storm duration
= 24 hrs
Q (cfs)
14.00
12.00
10.00
M
. M@
4.00
2.00
Peak discharge
Time to peak
Hyd. volume
Curve number
Hydraulic length
Time of conc. (Tc)
Distribution
Shape factor
Pre - DA#2
Hyd. No. 2 -- 100 Year
Wednesday, 12 / 14 / 2022
= 12.55 cfs
= 718 min
= 25,209 cuft
= 60
= 0 ft
= 5.00 min
= Type II
= 484
Q (cfs)
14.00
12.00
10.00
M
ee
4.00
ItM
0.00
120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Hyd No. 2 Time (min)

29
Hydrograph Report
Hydraflow Hydrographs Extension for AUtodeskS Civil 3DO by Autodesk, Inc. v2022
Wednesday, 12 / 14 / 2022
Hyd. No. 3
Post - DA#1 to SCM
Hydrograph type
= SCS Runoff
Peak discharge
= 91.38 cfs
Storm frequency
= 100 yrs
Time to peak
= 717 min
Time interval
= 1 min
Hyd. volume
= 189,426 cuft
Drainage area
= 10.300 ac
Curve number
= 76
Basin Slope
= 0.0 %
Hydraulic length
= 0 ft
Tc method
= User
Time of conc. (Tc)
= 5.00 min
Total precip.
= 7.73 in
Distribution
= Type II
Storm duration
= 24 hrs
Shape factor
= 484
Q (cfs)
100.00
90.00
80.00
70.00
60.00
50.00
40.00
30.00
20.00
10.00
0 00
0 120 240 360 480 600 720 840 960 1080 1200 1320
Hyd No. 3 Time (min)

30
Hydrograph Report
Hydraflow Hydrographs Extension for AUtodeskS Civil 3DO by Autodesk, Inc. v2022
Wednesday, 12 / 14 / 2022
Hyd. No. 4
Post - DA#1 BYP
Hydrograph type
= SCS Runoff
Peak discharge
= 6.808 cfs
Storm frequency
= 100 yrs
Time to peak
= 720 min
Time interval
= 1 min
Hyd. volume
= 15,465 cuft
Drainage area
= 1.460 ac
Curve number
= 58
Basin Slope
= 0.0 %
Hydraulic length
= 0 ft
Tc method
= User
Time of conc. (Tc)
= 9.00 min
Total precip.
= 7.73 in
Distribution
= Type II
Storm duration
= 24 hrs
Shape factor
= 484
Q (cfs)
7.00
. 11
5.00
4.00
3.00
2.00
1.00
Post - DA#1 BYP
Hyd. No. 4 -- 100 Year
Q (cfs)
7.00
. Me
5.00
4.00
3.00
2.00
1.00
0.00 ' 1 1 1J -- ' ' ' ' 0.00
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
— Hyd No. 4 Time (min)

Hydrograph Report
31
Hydraflow Hydrographs Extension for AUtodeskS Civil 3DO by Autodesk, Inc. v2022
Hyd. No. 5
Post - DA#2 BYP
Hydrograph type
= SCS Runoff
Storm frequency
= 100 yrs
Time interval
= 1 min
Drainage area
= 1.340 ac
Basin Slope
= 0.0 %
Tc method
= User
Total precip.
= 7.73 in
Storm duration
= 24 hrs
Q (cfs)
10.00
WE
4.00
2.00
Peak discharge
Time to peak
Hyd. volume
Curve number
Hydraulic length
Time of conc. (Tc)
Distribution
Shape factor
Post - DA#2 BYP
Hyd. No. 5 -- 100 Year
120 240 360 480 600 720 840
Hyd No. 5
Wednesday, 12 / 14 / 2022
= 8.894 cfs
= 718 min
= 17,893 cuft
= 64
= 0 ft
= 5.00 min
= Type II
= 484
Q (cfs)
10.00
WE
ItM
4.00
ItM
0.00
960 1080 1200 1320 1440 1560
Time (min)

32
Hydrograph Report
Hydraflow Hydrographs Extension for AUtodeskS Civil 3DO by Autodesk, Inc. v2022
Wednesday, 12 / 14 / 2022
Hyd. No. 6
SCM Routing
Hydrograph type
= Reservoir
Peak discharge
= 45.88 cfs
Storm frequency
= 100 yrs
Time to peak
= 723 min
Time interval
= 1 min
Hyd. volume
= 179,003 cuft
Inflow hyd. No.
= 3 - Post - DA#1 to SCM
Max. Elevation
= 913.63 ft
Reservoir name
= SCM
Max. Storage
= 69,788 cuft
Storage Indication method used.
Q (cfs)
100.00
90.00
:1 11
70.00
60.00
50.00
40.00
30.00
SCM Routing
Hyd. No. 6 -- 100 Year
Q (cfs)
100.00
90.00
:1 11
70.00
60.00
50.00
40.00
30.00
1 11 1���"�� 1 11
1 1 �1 •1 �:1 •11 1 :�1 •.1 1:1 11 1 ��1 •1

Hydrograph
Report
33
Hydraflow Hydrographs Extension for AUtodeskS Civil 3DO by Autodesk, Inc. v2022
Wednesday, 12 / 14 / 2022
Hyd. No. 7
Post - POA#1
Hydrograph type
= Combine
Peak discharge
= 51.74 cfs
Storm frequency
= 100 yrs
Time to peak
= 722 min
Time interval
= 1 min
Hyd. volume
= 194,468 cuft
Inflow hyds.
= 4, 6
Contrib. drain. area
= 1.460 ac
Post - POA#1
Q (cfs) Hyd. No. 7 -- 100 Year Q (cfs)
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 0.00
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Time (min)
— Hyd No. 7 — Hyd No. 4 Hyd No. 6

Pre Development
Drainage Area
Map
Page 8 of 13

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Date: 2022.12.14
22:36:23-05'00'
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DRAWN BY:
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PROJECT NO.
22-271
SHEET NO.
PRE
1
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Post Development
Drainage Area
Map
Page 9 of 13

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by Jonathan
Cory Cory George
Date: 2022.12.14
George 22:35:23-05'00'
50 0 25 50 100
SCALE: 1" = 50'
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SCALE:
1"=50'
DATE:
12-14-2022
DRAWN BY:
JCG
PROJECT NO.
22-271
SHEET NO.
POST
1
2
3
0
5
0
7
0

Outlet
Protection
Page 10 of 13

User Input Data
Calculated Value
Reference Data
Designed By:
JCG Date: 9/12/2022
Checked By:
JCG Date: 9/12/2022
Company:
Pilot S&E
Project Name:
Pfafftown Self Storage
Project No.:
22-271
Site Location (City/Town) Pfafftown, NC
Culvert Id. EW-100
Total Drainage Area (acres) 10.3
Step 1. Determine the tad ater depth fiord channel characteristics below the
pipe outlet for the design capacity of the pipe_ If the tailuater depth is less
than half the outlet pipe diameter, it is classified nu'rdmum tailwater condition_
Hit is greater than half the pipe diameter, it is classified maxisi lLmi condition_
Pipes that outlet onto Wide $at areas with no defined chatuiel are assumed
to have a mini,num tailuwater condition unless reliable flood stage elevations
Show otherwise_
Outlet pipe diameter, Do (in.) 24
Tailwater depth (in.) 0
Minimum/Maximum tailwater? Min TW (Fig. 8.06a)
Discharge (cfs) 12.33
Velocity (ft./s) 8.12
Step 2. Based on the tailv4 ater conditions determined in step 1 _ enter Figure
$_06a or Figure 8_06b, and determine d50 riprag size and miniunun apron length
(L). The d_y size is the niediau stone size in a well -graded riprag apron_
Step 3. Detennine apron width at the pipe outlet, the apron shape, and the
apron width at the outlet end from the same figure used in Step 2_

Minimum TW
Figure 8.06a
Riprap d50, (ft.)
0.5
Minimum apron length, La (ft.)
12
Apron width at pipe outlet (ft.)
6
Apron shape
Trap
Apron width at outlet end (ft.)
14
,Step 4. Determine the maximum stone diameter:
dr,=1.5xd5o
Minimum TW
Max Stone Diameter, dmax (ft.) 0.75
Step 5. Determine the apron thickness:
Apron Thickness(ft.)
Apron thickness = 1.5 x d,.
Maximum TW
Figure 8.06b
0
2
Maximum TW
0
Minimum TW Maximum TW
1.125 0
Step 6. Fit the riprap apron to the site by making it level for the munimtun
length, L. , from Figure 8-06a or Figure 8-06b- Extend the apron farther
dowrnstream and along channel batiks iLmtil stability is assured- Keep the
apron as straight as possible and align it with the flow of the receiving stream_
Make any necessary alignment bends near the pipe outlet so that the entrance
into the recei'-img stream is straight -
Some locations may require lining of the entire channel cross section to asstue
stabilit-v-
It may be necessary to increase the size of riprap -where protection of the
channel side slopes is necessary (Appiondix 8.05)- Where overfalls exist at
pipe outlets or fiovvs are excessive, a phuige pool should be considered, see
page 8-06-8-

Figure 8.06a: Design of outlet protection from a round pipe flowing full, minimum
tailwater condition (Tw<0.5 diameter)
Discharge (0Isec)
Curves may not be extrapolated.
Figure 8.05a 0,Dsign of autie t protection protection Irom a round pipe flowing full, minirnum taiiwatcr condition (Tw c 0.5 diameter).
Rev. 12.93 8.06.3

Anti -Float Block
Calculations
Page 11 of 13

PILOT
.dLe, 0 -N-1
SURVEYING AND ENGINEERING
ANTI -FLOAT BLOCK CALCULATIONS
Project Name: Pfafftown Self Storage
Project Number: 22-271
Input Information
Inside Length =1 4.00 Ift
Inside Width = 4.00 ft
Wall Thickness = 6.00 lin
Inside Height of Riser = 7.50 ft
Weight of Concrete =1 142.00 Ipcf
Trash Rack Inputs
Concrete Present
Date: 12/14/2022
Calculated By: JCG
Base Length = 5.00 ft
Base Width = 5.00 ft
Base Thickness = 6.00 in
OD of Outlet Pipe = 30.00 in
Drain Pipe =1 8.00 lin
Bottom Length / Width = Ulft
ft
Top Length / Width = ft
Height =
Trash Rack Displacement = 38 cf
Riser Structure = 67.5 cf
Riser Base =1 12.5 Jcf
Outlet Pipe Opening = 2.45 cf
Drain Pipe Opening =1 0.17 Jcf
Total Concrete Less Openings = 77.37 cf
Weight of Concrete = 10986.70 Ibs

Water Displacement
Anti Float Design
Concrete Displacement = 77.37 cf
Trash Rack Displacement = 38.00 cf
Air Displacement = 122.63 cf
Total Displacement= 238.00 cf
Unit Weight of Water = 62.40 Ibs
Weight of Water Displaced = 14851.20 Ibs
Additional Weight Need = 3864.50 Ibs
Safety Factor = 1.15
Additional Weight Required = 4444.18 Ibs
Additional Concrete Required = 31.30 cf
Anti -Float Block Length
= 7.00
ft
Anti -Float Block Width
= 7.00
ft
Anti -Float Block Thickness
= 12.00
in
Anti -Float Block Displacement
= 49.00
cf
Anti -Float Block Weight = 6958.00 Ibs
Total Concrete Present = 126.37 cf
Total Concrete Weight = 17944.70 Ibs
Weight of Water Displaced = 14851.20 Ibs
Calculated Safety Factor = 1.21

Hydraflow
Modeling
Summary
Page 12 of 13

IT. 111,111111111111
Ouffall 0 4
—�-�6
Ouffall
I
3
Project File: Pfafflown_Storage.stm
Number of lines: 15 1 Date: 12/14/2022
Storm Sewers v2022.00

,� -iT*TM I I R -� ••
Page 1
Line
Alignment
Flow Data
Physical Data
Line ID
No.
Dnstr
Line
Defl
Junc
Known
Drng
Runoff
Inlet
Invert
Line
Invert
Line
Line
N
J-Loss
Inlet/
Line
Length
angle
Type
Q
Area
Coeff
Time
El Dn
Slope
El Up
Size
Shape
Value
Coeff
Rim El
No.
(ft)
(deg)
(cfs)
(ac)
M
(min)
(ft)
M
(ft)
(in)
(n)
(K)
(ft)
1
End
143.688
33.088
DrGrt
0.00
0.14
0.95
5.0
944.50
1.25
946.30
18
Cir
0.013
0.50
951.10
Pipe - 3
2
1
68.432
3.002
DrGrt
0.00
0.20
0.95
5.0
946.40
1.17
947.20
15
Cir
0.013
1.14
951.02
Pipe - 2
3
2
59.930
45.849
DrGrt
0.00
0.18
0.95
5.0
947.30
1.17
948.00
15
Cir
0.013
1.00
950.70
Pipe - 1
4
End
99.126
1.928
DrGrt
0.00
0.00
0.95
5.0
944.00
1.01
945.00
15
Cir
0.013
0.56
951.25
Pipe - 15
5
4
66.000
18.841
DrGrt
0.00
0.16
0.95
5.0
945.10
1.06
945.80
15
Cir
0.013
0.50
951.06
Pipe - 14
6
5
66.000
0.000
DrGrt
0.00
0.16
0.95
5.0
945.90
1.21
946.70
15
Cir
0.013
1.00
951.06
Pipe - 13
7
End
35.000
22.708
MH
0.00
0.00
0.00
5.0
937.00
3.71
938.30
24
Cir
0.013
1.00
949.50
Pipe - 8
8
7
113.000
86.588
MH
0.00
0.00
0.00
5.0
938.50
1.15
939.80
24
Cir
0.013
1.00
949.50
Pipe - 7
9
8
128.510
-89.780
DrGrt
0.00
0.24
0.95
5.0
940.00
1.40
941.80
24
Cir
0.013
2.25
951.06
Pipe - 6
10
9
66.000
0.000
DrGrt
0.00
0.24
0.95
5.0
941.90
1.14
942.65
24
Cir
0.013
1.50
951.06
Pipe - 5
11
10
93360
0.000
DrGrt
0.00
1.27
0.75
5.0
942.75
1.07
943.75
18
Cir
0.013
1.00
947.75
Pipe - 4
12
9
153.000
-90.000
DrGrt
0.00
0.23
0.95
5.0
941.90
1.05
943.50
15
Cir
0.013
1.00
951.28
Pipe - 12
13
10
153.000
-90.000
DrGrt
0.00
0.23
0.95
5.0
942.75
1.14
944.50
15
Cir
0.013
1.00
951.28
Pipe - 11
14
9
158.000
90.000
DrGrt
0.00
0.22
0.95
5.0
941.90
1.01
943.50
15
Cir
0.013
1.00
951.28
Pipe - 10
15
10
165.500
90.000
DrGrt
0.00
0.25
0.95
5.0
942.75
1.06
944.50
15
Cir
0.013
1.00
951.20
Pipe - 9
Pfafftown Self Storage
Number of lines: 15
Date: 12/14/2022
Storm Sewers v2022.00

ILZ
L I � 11, li
Page 1
Struct
Structure ID
Junction
Rim
Structure
Line Out
Line In
No.
Type
Elev
Shape
Length
Width
Size
Shape
Invert
Size
Shape
Invert
(ft)
(ft)
(ft)
(in)
(ft)
(in)
(ft)
1
DI-102
DropGrate
951.10
Rect
4.00
4.00
18
Cir
946.30
15
Cir
946.40
2
DI-101
DropGrate
951.02
Rect
4.00
4.00
15
Cir
947.20
15
Cir
947.30
3
DI-100
DropGrate
950.70
Rect
4.00
4.00
15
Cir
948.00
4
DI-302
DropGrate
951.25
Rect
4.00
4.00
15
Cir
945.00
15
Cir
945.10
5
DI-301
DropGrate
951.06
Rect
4.00
4.00
15
Cir
945.80
15
Cir
945.90
6
DI-300
DropGrate
951.06
Rect
4.00
4.00
15
Cir
946.70
7
MH-204
Manhole
949.50
Rect
0.00
4.00
24
Cir
938.30
24
Cir
938.50
8
MH-203
Manhole
949.50
Rect
0.00
4.00
24
Cir
939.80
24
Cir
940.00
9
DI-202
DropGrate
951.06
Rect
4.00
4.00
24
Cir
941.80
24
Cir
941.90
15
Cir
941.90
15
Cir
941.90
10
DI-201
DropGrate
951.06
Rect
4.00
4.00
24
Cir
942.65
18
Cir
942.75
15
Cir
942.75
15
Cir
942.75
11
DI-200
DropGrate
947.75
Rect
4.00
4.00
18
Cir
943.75
12
DI-209
DropGrate
951.28
Rect
4.00
4.00
15
Cir
943.50
13
DI-208
DropGrate
951.28
Rect
4.00
4.00
15
Cir
944.50
14
DI-207
DropGrate
951.28
Rect
4.00
4.00
15
Cir
943.50
15
DI-206
DropGrate
951.20
Rect
4.00
4.00
15
Cir
944.50
L
Pfafftown Self Storage
- ------
Number of Structures: 15
------
[ Run Date: 12/1412022
Storm Sewers v2022.00

,� -iT*TM I I R -� •
Page 1
Line
Line ID
Flow
Line
Line
Line
Invert
Invert
Line
HGL
HGL
Minor
HGL
Dns
Junction
No.
rate
Size
shape
length
EL Dn
EL Up
Slope
Down
Up
loss
Junct
Line
Type
(cfs)
(in)
(ft)
(ft)
(ft)
N
(ft)
(ft)
(ft)
(ft)
No.
1
Pipe - 3
3.21
18
Cir
143.688
944.50
946.30
1.253
945.04
946.98
0.13
946.98
End
DropGrate
2
Pipe - 2
2.39
15
Cir
68.432
946.40
947.20
1.169
946.98
947.82
n/a
947.82
1
DropGrate
3
Pipe - 1
1.17
15
Cir
59.930
947.30
948.00
1.168
947.82
948.43
n/a
948.43 j
2
DropGrate
4
Pipe - 15
1.95
15
Cir
99.126
944.00
945.00
1.009
944.56
945.56
0.12
945.56
End
DropGrate
5
Pipe - 14
2.00
15
Cir
66.000
945.10
945.80
1.061
945.57
946.36
0.11
946.36
4
DropGrate
6
Pipe - 13
1.04
15
Cir
66.000
945.90
946.70
1.212
946.36
947.10
n/a
947.10 j
5
DropGrate
7
Pipe - 8
14.14
24
Cir
35.000
937.00
938.30
3.714
938.35
939.65
n/a
939.65
End
Manhole
8
Pipe - 7
1432
24
Cir
113.000
938.50
939.80
1.150
939.65
941.16
0.61
941.16
7
Manhole
9
Pipe - 6
14.52
24
Cir
128.510
940.00
941.80
1.401
941.16
943.17
1.40
943.17
8
DropGrate
10
Pipe - 5
10.47
24
Cir
66.000
941.90
942.65
1.136
943.17
943.81
n/a
943.81 j
9
DropGrate
11
Pipe - 4
6.53
18
Cir
93.360
942.75
943.75
1.071
943.81
944.74
n/a
944.74 j
10
DropGrate
12
Pipe - 12
1.50
15
Cir
153.000
941.90
943.50
1.046
943.17
943.98
n/a
943.98 j
9
DropGrate
13
Pipe - 11
1.50
15
Cir
153.000
942.75
944.50
1.144
943.81
944.98
n/a
944.98 j
10
DropGrate
14
Pipe - 10
1.43
15
Cir
158.000
941.90
943.50
1.013
943.17
943.97
n/a
943.97 j
9
DropGrate
15
Pipe - 9
1.63
15
Cir
165.500
942.75
944.50
1.057
943.81
945.01
n/a
945.01 j
10
DropGrate
Pfafftown Self Storage
Number of lines: 15
Run Date: 12/1412022
NOTES: Return period= 10Yrs. ;j -Line contains hyd. jump.
Storm Sewers v2022.00

Page 1
Station
Len
Drng Area
Rnoff
Area x C
Tc
Rain
Total
Cap
Vel
Pipe
Invert Elev
HGL Elev
Grnd / Rim Elev
Line ID
coeff
(1)
flow
full
Line
To
Incr
Total
Incr
Total
Inlet
Syst
Size
Slope
Dn
Up
Dn
Up
Dn
Up
Line
(ft)
(ac)
(ac)
(C)
(min)
(min)
(in/hr)
(cfs)
(cfs)
(ft1s)
(in)
00
(ft)
00
(ft)
(ft)
00
I
End
143.688
0.14
0.52
0.95
0.13
0.49
5.0
6.6
6.5
3.21
1175
4.88
18
1.25
944.50
946.30
945.04
946.98
946.00
951.10
Pipe - 3
2
1
68.432
0.20
0.38
0.95
0.19
0.36
5.0
6.0
6.6
2.39
6.98
4.11
15
1.17
946.40
947.20
946.98
947.82
951.10
951.02
Pipe - 2
3
2
59.930
0.18
0.18
0.95
0.17
0.17
5.0
5.0
6.9
1.17
6.98
2.81
15
1.17
947.30
948.00
947.82
948.43
951.02
950.70
Pipe - 1
4
End
99126
0.00
0.32
0.95
0.00
0.30
5.0
7.0
6.4
1.95
6A9
3.70
15
1.01
944.00
945.00
944.56
945.56
944.00
951.25
Pipe - 15
5
4
66.000
0.16
0.32
0.95
0.15
0.30
5.0
6.3
6.6
MO
6.65
4.23
15
1.06
945.10
945.80
945.57
946.36
951.25
951.06
Pipe - 14
6
5
66.000
0.16
0.16
0.95
0.15
0.15
5.0
5.0
6.9
1.04
7.11
2.80
15
1.21
945.90
946.70
946.36
947.10
951.06
951.06
Pipe - 13
7
End
35.000
0.00
2.68
0.00
0.00
2.29
5.0
8.3
6.2
14.14
43.59
6.25
24
3.71
937.00
938.30
938.35
939.65
940.52
949.50
Pipe - 8
8
7
113.000
0.00
2.68
0.00
0.00
2.29
5.0
7.9
6.2
14.32
24.26
6.96
24
1.15
938.50
939.80
939.65
941.16
949.50
949.50
Pipe - 7
9
8
128.510
0.24
2.68
0.95
0.23
2.29
5.0
7A
6.3
14.52
26.77
6.99
24
1.40
940.00
941.80
941.16
943.17
949.50
951.06
Pipe - 6
10
9
66.000
0.24
1.99
0.95
0.23
1.64
5.0
7.1
6.4
10A7
24.11
5.26
24
1.14
941.90
942.65
943.17
943.81
951.06
951.06
Pipe - 5
11
10
93.360
1.27
1.27
0.75
0.95
0.95
5.0
5.0
6.9
6.53
10.87
5.10
18
1.07
942.75
943.75
943.81
944.74
951.06
947.75
Pipe - 4
12
9
153.000
0.23
0.23
0.95
0.22
0.22
5.0
5.0
6.9
1.50
6.60
2.32
15
1.05
941.90
943.50
943.17
943.98
951.06
951.28
Pipe - 12
13
10
153.000
0.23
0.23
0.95
0.22
0.22
5.0
5.0
6.9
1.50
6.91
2.38
15
1.14
942.75
944.50
943.81
944.98
951.06
951.28
Pipe - 11
14
9
158.000
0.22
0.22
0.95
0.21
0.21
5.0
5.0
6.9
1.43
6.50
2.27
15
1.01
941.90
943.50
943.17
943.97
951.06
951.28
Pipe - 10
15
10
165.500
0.25
0.25
0.95
0.24
0.24
5.0
5.0
6.9
1.63
6.64
2.48
15
1.06
942.75
944.50
943.81
945.01
951.06
951.20
Pipe - 9
Pfafftown Self Storage
Number of lines: 15
Run Date: 12/14/2022
NOTES:Intensity = 136.50 (Inlet time + 21,50) 10.91; Return period =Yrs. 10 c = cir e = ellip b = box
Storm Sewers v2022.00

Erosion Control
Calculations
Page 13 of 13

EROSION CONTROL CALCULATIONS
For: C®C Investments, LLC
4049 West Pine Street
Mount Airy, NC 27030
Pfafftown Self Storage
-PILOT
SURVEYING & ENGINEERING
Project Number: 22-271
By: Cory George, PE, PLS
106 S. Depot Street
Suite D
Pilot Mountain, NC 27041

�� PILOT
�' SIIR VEYING �N❑ ENGINEERINE.
Runoff Calculations - Rational Method
Project Name: Pfafftown Self Storage
Project Number: 22-271
Subbasin ID: Skimmer
Runoff Coefficients
Date: 12/14/2022
Calculated I JCG
Land Use
C
Land Use
C
Business-
Lawns -
Downtown areas
0.70-0.95
Sandy soil, flat, 2%
0.05-0.10
Neighborhood areas
0.50-0.70
Sandy soil, ave_,
0.10-0.15
2-7%
Residential:
Sandy soil, steep.
0.15-0.20
Single-family areas
0.30-0.50
7%
Multi units, detached
0.40-0.60
Heavy soil, flat, 2%
0.13-0.17
Multi units, Attached
0_60-0.75
Heavy sail, ave_,
0.1" 22
Suburban
0.25-0.40
2-7%
Industrial-
Heavy soil, steep,
70�
0.25-0.35
Light areas
0.50-0.80
Heavy areas
0-fi0-0-90
Agricultural land:
Parks, cemeteries
0.10-0.25
Bare packed soil
Smooth
0.30-0.60
Playgrounds
0.20-0.35
Rough
0.20-0.50
Cultivated rows
Railroad yard areas
0.20-0.40
Heavy soil no crop
0.30-0.60
Heavy soil with
Unimproved areas
0.1" 30
Crop
0.20-0.50
Streets-
Sandy soil no crop
0.20-0.40
Asphalt
0.70-095
Sandy soil with
Concrete
0.80-0.95
Crop
0.10-0.25
Brick
0.70-0.85
Pasture
Heavy soil
0.1" 45
Drives and walks
0.75-0.85
Sandy soil
0.05-0.25
Woodlands
0.45-0.25
Roofs
0.75-0.85
NOTE: The designer
must use judgement to select the appropriate
C
value within the range
for the appropriate land use. Generally,
larger
anus with permeable
soils, fiat slopes, and dense vegetation
should
have lowest C values.
Smaller areas with slowly permeable
soils, steep
slopes, and sparse vegetation should be assigned highest C
values_
Source: American Society of Civil Engineers

Watershed Breakdown
Cnntrihutinn Area Coefficient Area rarl Comments
Subarea A
0.25 0.000
0.60 6.935
Wooded, steep
Subarea B
Bare Soil (DA)
Subarea C
0.30
1.304
Grass, 2-7%
Subarea D
0.85
1.251
Impervious
Total Area = 9.490 acres
Weighted Runoff Coefficient = 0.59
Time of Concentration
Reference USDA TR-55
Segment 1: Overland Flow
Length =
100
ft
Upstream Invert =
948.50
ft
Downstream Invert =
941.00
ft
Slope =
0.0750
ft/ft
Manning's n =
0.02
Bare Earth
P (2-year/24-hour) =1
3.43
linches
Segment Time =1
1.11
min
Segment 2: Concentrated Flow
Length =
483
ft
Upstream Invert=
941.00
ft
Downstream Invert=
918.00
ft
Slope =
0.0476
ft/ft
Paved? =
No
Velocity =
3.52
ft/sec
Segment Time =
2.29
min
Time of Concentration = 3.40 min

Rainfall Intensity (in/hr)
Reference NOAA Atlas 14
Peak Flow Rates
Ration Method
Return Interval ears
Duration min 2 1 10 1 25 1 100
5 6.86 1 7.66 1 8.68
= CLA
Peak Flow Rates
Weighted Runoff Coefficient = 0.59
Total Area = 9.490 ac
Q2 =
29.5�
cfs
Q10 =
38.52
cfs
Q25 =
43.01
cfs
Qioo =
48.74
cfs

'"%
P1 LOT
SURVEYING AN❑ ENGINEERING
Erosion Control Calculations - Skimmer Basin
Project Name: Pfafftown Self Storage
Project Number: 22-271
Subbasin ID: SB-1
Stage - Storage - As Graded
Date: 12/14/2022
Calculated By: JCG
Contour
Average
Incremental
Accumulated
Contour
Contour
Contour
Contour
Stage
Area
Area
Volume
Volume
(feet)
(feet)
(SF)
(SF)
(CF)
(CF)
909
0
11,669
910
1
13,056
12,363
12,363
12,363
912
3
16,002
14,529
29,058
41,421
912.5 3.5
16,772
16,387
8,194
49,614
913
17,559
17,166
8,583
58,197
914
19,173
20,841
18,366
20,007
1 18,366
1 20,007
76,563
96,570
915
Required Volume = 9,405
Provided Volume = 49,614 Good
Required Surface Area = 12,520
Provided Surface Area = 16,772 Good
riser crest

PILOT
SURVEYING AND ENGINEERING
Erosion Control Calculations - Skimmer Basin
Project Name: Pfafftown Self Storage
Project Number: 22-271
Subbasin ID: SB-1
Skimmer Basin Design Parameters
Drainage Area =
6.245
acres
Peak Flow, Q10
= 38.52
cfs
Disturbed Area
= 5.225
acres
Required Basin Dimensions
Min. Volume
= 1800
cf per disturbed acre
Req. Volume
= 9405
cf
Min. Surface Area
= 325
sf per Q10 cfs
Req. Surface Area
= 12520
sf
Volume Provided = 49614 cf, at riser crest
Surface Area Provided =1 16772 Isf, at riser crest
Skimmer Orifice Calculations
Min. Drawdown Time = 2 days
Dewater Volume = 9405 cf
Daily Flow Req, Qd = 4703 cfd
Skimmer Size = Iin
Min. Orifice Size = 2.23 in
Orifice Size = 2 in
Drawdown Time = 2.49 days
Date: 12/14/2022
Calculated E JCG
Skimmer Size (in) I Head on Skimmer (ft)
1.5
0.125
2
0.167
2.5
0.208
3
0.25
4
0.333
5
0.333
6
0.417
8
0.5

1
2 1 3 1 4 1 5 1 6 1 7
F
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BERNIE JACKSON
PIN: 5899-50-2399
DEED BK: 2137 PG: 1095
BERNIE JACKSON
PIN: 5899-50-2287
DEED BK: 2137 PG: 1096
KARAN GUARINO
PIN: 5899-50-2174
DEED BK: 3505 PG: 366
FORSYTH VENTURES, INC
r/ r����� ���� PROPOSED TREE SAVE AREA
� ���� PIN: 5899-90-1759
EXISTING PROPERTY LINE (TYP.) I I I OUTL T\S RUA�TSRE ` / \ \ / _ DEED BK: 1822 PG: 213
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George
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EXISTING GUY LINE (TYP.)
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EXISTING POWER POLE (TYP.)
�EBRIS T �\ MOVED
/ I \ � RAVEL TO R MW /
Digitally signed by
Jonathan Cory
George
Date: 2022.12.14
22:13:20-05'00'
EX. CONCRET€TOBEE RE OWED /. �. \ . EX. DEBRIS TO BE REMOVED
J TOTAL DISTURBED AREA: 8.83 ACRES
'k- EXIS G WATER '
/
VA YP.) � E'x, I -
-�to" Concrete�loc-v—
LEGEND
��d, / ■ _ndArick Retail Building .. \ \/ / EXISTING IRON MON.
01 \ ~ \ . . . . EX. C CRETE TO BE REMOVED ® SET 5/8" REBAR
\ \ \ CALCULATED POINT
. . . .� . . . \ . . 0 TRAVERSE STATION
CONCRETE MONUMENT
// �✓ • EX. POWER POLE TO BE MOVED (TYP.) ® PK NAIL
EXISTING WATER METER (TYP.) ,J` \ / Z R/W MONUMENT
. .A . . . . . . . . . . BUILDING TO BE REMOVED 9 R.R. SPIKE
\ / `
EX. F E O BE Q STONE
61 REMgVE P.) �\ . . . . . . EX. CONCRETE TO REMAIN ® WATER METER
• • • • SEWER CLEANOUT
d R �� Rqr d / `` \ / �� EXISTING B ILDING TO REMAIN QS SEWER MANHOLE
d d d STORM MANHOLE
\ FIRE HYDRANT
SEWARp CR \ ... � UTILITY POLE
SR- 1460 1 6OFT WIDTH PUBLIC R/W �`s6>1/ SINGLE POLE SIGN
—R/W
AR/W R/W R/W
��d 8 EX. OVERHEA
\ \ POWER TO BE
REMOVED (TYP.)
\ TS m
\ \ w
\ N
pd
WATER VALVE
O
WELL
GUY WIRE
BOUNDARY LINE
LINE NOT SURVEYED
— R/W—
RIGHT OF WAY
— — —
— EASEMENT
— P —
OVERHEAD ELEC
— E —
UNDERGRD ELEC
— w —
WATER LINE
SS
SEWER LINE
— GAS—
GAS LINE
— SD —
STORM LINE
DITCH CNTRLINE
— x —CHAIN
LNK FNCE
50 0 25 50 100
SCALE: 1" = 50'
z
0
LD
w
Of
w
z
0
Wcc
W
W
z0
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z
V
z
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SEAL
042031 =
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a
0
z
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a
SCALE:
ill =50'
DATE:
12-13-2022
DRAWN BY:
JCG
PROJECT NO.
22-271
SHEET NO.
DA-1
1
2
3 1 4
5
0
7
0