SW3210201_Calculation Package_20210428

LITTLE
DIVERSIFIED ARCHITECTURAL CONSULTING
Union County Southwest Regional Library
Town of Waxhaw I Union County I North Carolina
CALCULATIONS FOR:
Storm Drainage System
Curb Flumes
Riprap Aprons
Skimmer Sediment Basins
PREPARED FOR:
NCDEMLR - Central Office
512 North Salisbury Street
1612 Mail Service Center
Raleigh, North Carolina 27699
Submitted: February 151h, 2021
Resubmitted: April 261h, 2021
Little Project Number
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051865
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PREPARED BY:
Little Diversified Architectural Consulting
615 South College Street, Suite 1600
Charlotte, North Carolina 28202
111.9475.00
615 South College Street, Suite 1600 1 Charlotte, North Carolina 28202 1 p: 704.525.6350 1 www.litLleonline.com

LITTLE
DIVERSIFIED ARCHITECTURAL CONSULTING
PROJECT NARRATIVE
The proposed Union County Southwest Regional Library is a new approximately
20,000 square -foot, single story facility on a county -owned parcel south of the
Cuthbertson Middle and High Schools on Cuthbertson Road at the south entry to the
school access drive. The projectwill also consist of a parking area atthe north ofthe
facility for approximately 85 parking spaces. This project is considered a low -density
project since it contains less than 24% built -upon -area.
During construction, temporary skimmer sediment basins, diversion ditches, slope
drains, and erosion control matting will be installed to provide erosion control.
NOTE. The most recent version of these calculations shall supersede all others.
615 South College Street, Suite 1600 1 Charlotte, North Carolina 28202 1 p: 704.525.6350 1 www.littleonline.com

TABLE OF CONTENTS
Storm Drainage System
Curb Flumes
Riprap Aprons
Skimmer Sediment Basins
LITTLE"
DIVERSIFIED ARCHITECTURAL CONSULTING
615 South College Street, Suite 1600 1 Charlotte, North Carolina 28202 1 p: 704.525.6350 1 www.litLleonline.com

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Custom Soil Resource Report
Soil Map
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34° 58' 2" N ' a
523150 523210 523270 523330 523390 523450
3
Map Scale: 1:2,670 if printed on A landscape (11" x 8.5") sheet.
Meters
N 0 35 70 140 210
Feet
0 100 200 400 600
Map projection: Web Mercator Comer coordinates: WGS84 Edge tics: UTM Zone 17N WGS84
6
523510 523570 523630
523510 523570 523630
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MAP LEGEND
Area of Interest (AOI)
0
Area of Interest (AOI)
Soils
0
Soil Map Unit Polygons
im 0
Soil Map Unit Lines
■
Soil Map Unit Points
Special
Point Features
Blowout
Borrow Pit
Clay Spot
Closed Depression
Gravel Pit
.4
Gravelly Spot
0
Landfill
Lava Flow
Marsh or swamp
+
Mine or Quarry
Miscellaneous Water
Perennial Water
Rock Outcrop
Saline Spot
Sandy Spot
Severely Eroded Spot
Sinkhole
Slide or Slip
oa
Sodic Spot
Custom Soil Resource Report
MAP INFORMATION
A
Spoil Area
The soil surveys that comprise your AOI were mapped at
1:24,000.
Stony Spot
Very Stony Spot
Warning: Soil Map may not be valid at this scale.
Wet Spot
Enlargement of maps beyond the scale of mapping can cause
Other
misunderstanding of the detail of mapping and accuracy of soil
.-
Special Line Features
line placement. The maps do not show the small areas of
contrasting soils that could have been shown at a more detailed
Water Features
scale.
-
Streams and Canals
Transportation
Please rely on the bar scale on each map sheet for map
�}}
Rails
measurements.
Interstate Highways
Source of Map: Natural Resources Conservation Service
US Routes
Web Soil Survey URL:
Coordinate System: Web Mercator (EPSG:3857)
Major Roads
Local Roads
Maps from the Web Soil Survey are based on the Web Mercator
projection, which preserves direction and shape but distorts
Background
distance and area. A projection that preserves area, such as the
Aerial Photography
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: Union County, North Carolina
Survey Area Data: Version 20, Jun 3, 2020
Soil map units are labeled (as space allows) for map scales
1:50,000 or larger.
Date(s) aerial images were photographed: Jul 18, 2011—Nov
25, 2017
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.
7

Custom Soil Resource Report
Map Unit Legend
Map Unit Symbol
Map Unit Name
Acres in AOI
Percent of AOI
BaB
Badin channery silt loam, 2 to 8
15.5
80.0%
percent slopes
CmB
Cid channery silt loam, 1 to 5
0.0
0.1 %
percent slopes
GsB
Goldston-Badin complex, 2 to 8
1.7
8.9%
percent slopes
TbB2
Tarrus gravelly silty clay loam, 2
0.1
0.8%
to 8 percent slopes,
moderately eroded
TbC2
Tarrus gravelly silty clay loam, 8
2.0
10.3%
to 15 percent slopes,
moderately eroded
Totals for Area of Interest
19.4
100.0%
Map Unit Descriptions
The map units delineated on the detailed soil maps in a soil survey represent the
soils or miscellaneous areas in the survey area. The map unit descriptions, along
with the maps, can be used to determine the composition and properties of a unit.
A map unit delineation on a soil map represents an area dominated by one or more
major kinds of soil or miscellaneous areas. A map unit is identified and named
according to the taxonomic classification of the dominant soils. Within a taxonomic
class there are precisely defined limits for the properties of the soils. On the
landscape, however, the soils are natural phenomena, and they have the
characteristic variability of all natural phenomena. Thus, the range of some
observed properties may extend beyond the limits defined for a taxonomic class.
Areas of soils of a single taxonomic class rarely, if ever, can be mapped without
including areas of other taxonomic classes. Consequently, every map unit is made
up of the soils or miscellaneous areas for which it is named and some minor
components that belong to taxonomic classes other than those of the major soils.
Most minor soils have properties similar to those of the dominant soil or soils in the
map unit, and thus they do not affect use and management. These are called
noncontrasting, or similar, components. They may or may not be mentioned in a
particular map unit description. Other minor components, however, have properties
and behavioral characteristics divergent enough to affect use or to require different
management. These are called contrasting, or dissimilar, components. They
generally are in small areas and could not be mapped separately because of the
scale used. Some small areas of strongly contrasting soils or miscellaneous areas
are identified by a special symbol on the maps. If included in the database for a
given area, the contrasting minor components are identified in the map unit
descriptions along with some characteristics of each. A few areas of minor
components may not have been observed, and consequently they are not
mentioned in the descriptions, especially where the pattern was so complex that it
0

Custom Soil Resource Report
was impractical to make enough observations to identify all the soils and
miscellaneous areas on the landscape.
The presence of minor components in a map unit in no way diminishes the
usefulness or accuracy of the data. The objective of mapping is not to delineate
pure taxonomic classes but rather to separate the landscape into landforms or
landform segments that have similar use and management requirements. The
delineation of such segments on the map provides sufficient information for the
development of resource plans. If intensive use of small areas is planned, however,
onsite investigation is needed to define and locate the soils and miscellaneous
areas.
An identifying symbol precedes the map unit name in the map unit descriptions.
Each description includes general facts about the unit and gives important soil
properties and qualities.
Soils that have profiles that are almost alike make up a soil series. Except for
differences in texture of the surface layer, all the soils of a series have major
horizons that are similar in composition, thickness, and arrangement.
Soils of one series can differ in texture of the surface layer, slope, stoniness,
salinity, degree of erosion, and other characteristics that affect their use. On the
basis of such differences, a soil series is divided into soil phases. Most of the areas
shown on the detailed soil maps are phases of soil series. The name of a soil phase
commonly indicates a feature that affects use or management. For example, Alpha
silt loam, 0 to 2 percent slopes, is a phase of the Alpha series.
Some map units are made up of two or more major soils or miscellaneous areas.
These map units are complexes, associations, or undifferentiated groups.
A complex consists of two or more soils or miscellaneous areas in such an intricate
pattern or in such small areas that they cannot be shown separately on the maps.
The pattern and proportion of the soils or miscellaneous areas are somewhat similar
in all areas. Alpha -Beta complex, 0 to 6 percent slopes, is an example.
An association is made up of two or more geographically associated soils or
miscellaneous areas that are shown as one unit on the maps. Because of present
or anticipated uses of the map units in the survey area, it was not considered
practical or necessary to map the soils or miscellaneous areas separately. The
pattern and relative proportion of the soils or miscellaneous areas are somewhat
similar. Alpha -Beta association, 0 to 2 percent slopes, is an example.
An undifferentiated group is made up of two or more soils or miscellaneous areas
that could be mapped individually but are mapped as one unit because similar
interpretations can be made for use and management. The pattern and proportion
of the soils or miscellaneous areas in a mapped area are not uniform. An area can
be made up of only one of the major soils or miscellaneous areas, or it can be made
up of all of them. Alpha and Beta soils, 0 to 2 percent slopes, is an example.
Some surveys include miscellaneous areas. Such areas have little or no soil
material and support little or no vegetation. Rock outcrop is an example.
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Custom Soil Resource Report
Union County, North Carolina
BaB—Badin channery silt loam, 2 to 8 percent slopes
Map Unit Setting
National map unit symbol: 2t80y
Elevation: 300 to 1,100 feet
Mean annual precipitation: 43 to 49 inches
Mean annual air temperature: 59 to 63 degrees F
Frost -free period: 215 to 245 days
Farmland classification: Farmland of statewide importance
Map Unit Composition
Badin and similar soils: 90 percent
Minor components: 10 percent
Estimates are based on observations, descriptions, and transects of the mapunit.
Description of Badin
Setting
Landform: Interfluves
Landform position (two-dimensional): Summit, shoulder
Landform position (three-dimensional): Interfluve
Down -slope shape: Linear
Across -slope shape: Convex
Parent material: Residuum weathered from metasedimentary rock and/or
metavolcanics
Typical profile
A - 0 to 6 inches: channery silt loam
Bt - 6 to 35 inches: silty clay
Cr- 35 to 43 inches: bedrock
R - 43 to 53 inches: bedrock
Properties and qualities
Slope: 2 to 8 percent
Depth to restrictive feature: 24 to 40 inches to paralithic bedrock; 40 to 59 inches
to lithic bedrock
Drainage class: Well drained
Runoff class: Medium
Capacity of the most limiting layer to transmit water (Ksat): Very low to high (0.00
to 1.98 in/hr)
Depth to water table: More than 80 inches
Frequency of flooding: None
Frequency of ponding: None
Available water capacity: Low (about 6.0 inches)
Interpretive groups
Land capability classification (irrigated): None specified
Land capability classification (nonirrigated): 3e
Hydrologic Soil Group: C
Hydric soil rating: No
10

Custom Soil Resource Report
Minor Components
Goldston
Percent of map unit: 5 percent
Landform: Interfluves
Landform position (two-dimensional): Summit, shoulder
Landform position (three-dimensional): Interfluve
Down -slope shape: Convex
Across -slope shape: Convex
Hydric soil rating: No
Tatum
Percent of map unit: 5 percent
Landform: Interfluves
Landform position (two-dimensional): Summit, shoulder
Landform position (three-dimensional): Interfluve
Down -slope shape: Linear
Across -slope shape: Convex
Hydric soil rating: No
CmB—Cid channery silt loam, 1 to 5 percent slopes
Map Unit Setting
National map unit symbol: 3wOq
Elevation: 200 to 650 feet
Mean annual precipitation: 37 to 60 inches
Mean annual air temperature: 59 to 66 degrees F
Frost -free period: 200 to 240 days
Farmland classification: Farmland of statewide importance
Map Unit Composition
Cid and similar soils: 85 percent
Estimates are based on observations, descriptions, and transects of the mapunit.
Description of Cid
Setting
Landform: Interfluves
Landform position (two-dimensional): Summit
Landform position (three-dimensional): Interfluve
Down -slope shape: Convex
Across -slope shape: Linear
Parent material: Residuum weathered from metavolcanics and/or residuum
weathered from argillite
Typical profile
Ap - 0 to 9 inches: channery silt loam
Bt - 9 to 22 inches: silty clay loam
BC - 22 to 27 inches: channery silty clay
Cr- 27 to 32 inches: weathered bedrock
11

Custom Soil Resource Report
R - 32 to 80 inches: unweathered bedrock
Properties and qualities
Slope: 2 to 6 percent
Depth to restrictive feature: 20 to 40 inches to paralithic bedrock; 20 to 40 inches
to lithic bedrock
Drainage class: Moderately well drained
Runoff class: Low
Capacity of the most limiting layer to transmit water (Ksat): Very low to moderately
high (0.00 to 0.20 in/hr)
Depth to water table: About 12 to 30 inches
Frequency of flooding: None
Frequency of ponding: None
Available water capacity. Low (about 4.0 inches)
Interpretive groups
Land capability classification (irrigated): None specified
Land capability classification (nonirrigated): 2e
Hydrologic Soil Group: D
Hydric soil rating: No
GsB—Goldston-Badin complex, 2 to 8 percent slopes
Map Unit Setting
National map unit symbol: 3wl1
Elevation: 200 to 650 feet
Mean annual precipitation: 37 to 60 inches
Mean annual air temperature: 59 to 66 degrees F
Frost -free period: 200 to 240 days
Farmland classification: Not prime farmland
Map Unit Composition
Goldston and similar soils: 45 percent
Badin and similar soils: 40 percent
Estimates are based on observations, descriptions, and transects of the mapunit.
Description of Goldston
Setting
Landform: Interfluves
Landform position (two-dimensional): Summit
Landform position (three-dimensional): Interfluve
Down -slope shape: Convex
Across -slope shape: Convex
Parent material: Residuum weathered from metavolcanics and/or argillite
Typical profile
A - 0 to 5 inches: very channery silt loam
Bw - 5 to 16 inches: very channery silt loam
Cr - 16 to 27 inches: weathered bedrock
R - 27 to 80 inches: unweathered bedrock
12

Custom Soil Resource Report
Properties and qualities
Slope: 2 to 8 percent
Depth to restrictive feature: 10 to 20 inches to paralithic bedrock; 20 to 40 inches
to lithic bedrock
Drainage class: Well drained
Runoff class: Medium
Capacity of the most limiting layer to transmit water (Ksat): Very low to high (0.00
to 1.98 in/hr)
Depth to water table: More than 80 inches
Frequency of flooding: None
Frequency of ponding: None
Available water capacity: Very low (about 1.7 inches)
Interpretive groups
Land capability classification (irrigated): None specified
Land capability classification (nonirrigated): 4s
Hydrologic Soil Group: D
Hydric soil rating: No
Description of Badin
Setting
Landform: Hillslopes on ridges
Landform position (two-dimensional): Backslope
Landform position (three-dimensional): Side slope
Down -slope shape: Linear
Across -slope shape: Convex
Parent material: Residuum weathered from metavolcanics and/or argillite
Typical profile
A - 0 to 7 inches: channery silt loam
Bt - 7 to 28 inches: silty clay
Cr- 28 to 41 inches: weathered bedrock
R - 41 to 80 inches: unweathered bedrock
Properties and qualities
Slope: 4 to 8 percent
Depth to restrictive feature: 20 to 40 inches to paralithic bedrock; 40 to 80 inches
to lithic bedrock
Drainage class: Well drained
Runoff class: Medium
Capacity of the most limiting layer to transmit water (Ksat)
to 1.98 in/hr)
Depth to water table: More than 80 inches
Frequency of flooding: None
Frequency of ponding: None
Available water capacity. Low (about 4.8 inches)
Interpretive groups
Land capability classification (irrigated): None specified
Land capability classification (nonirrigated): 2e
Hydrologic Soil Group: C
Hydric soil rating: No
Very low to high (0.00
13

Custom Soil Resource Report
TbB2—Tarrus gravelly silty clay loam, 2 to 8 percent slopes, moderately
eroded
Map Unit Setting
National map unit symbol: 2mx8q
Elevation: 200 to 1,400 feet
Mean annual precipitation: 37 to 60 inches
Mean annual air temperature: 59 to 66 degrees F
Frost -free period: 200 to 240 days
Farmland classification: All areas are prime farmland
Map Unit Composition
Tarrus, moderately eroded, and similar soils: 85 percent
Estimates are based on observations, descriptions, and transects of the mapunit.
Description of Tarrus, Moderately Eroded
Setting
Landform: Interfluves
Landform position (two-dimensional): Summit
Landform position (three-dimensional): Interfluve
Down -slope shape: Convex
Across -slope shape: Convex
Parent material: Residuum weathered from schist and/or other metamorphic rock
Typical profile
Ap - 0 to 6 inches: gravelly silty clay loam
Bt - 6 to 45 inches: silty clay
Cr - 45 to 80 inches: weathered bedrock
Properties and qualities
Slope: 2 to 8 percent
Depth to restrictive feature: 40 to 60 inches to paralithic bedrock
Drainage class: Well drained
Runoff class: Medium
Capacity of the most limiting layer to transmit water (Ksat): Very low to high (0.00
to 1.98 in/hr)
Depth to water table: More than 80 inches
Frequency of flooding: None
Frequency of ponding: None
Available water capacity: Low (about 4.5 inches)
Interpretive groups
Land capability classification (irrigated): None specified
Land capability classification (nonirrigated): 2e
Hydrologic Soil Group: B
Hydric soil rating: No
14

Custom Soil Resource Report
TbC2—Tarrus gravelly silty clay loam, 8 to 15 percent slopes,
moderately eroded
Map Unit Setting
National map unit symbol: 2mx8r
Elevation: 200 to 1,400 feet
Mean annual precipitation: 37 to 60 inches
Mean annual air temperature: 59 to 66 degrees F
Frost -free period: 200 to 240 days
Farmland classification: Farmland of statewide importance
Map Unit Composition
Tarrus, moderately eroded, and similar soils: 85 percent
Estimates are based on observations, descriptions, and transects of the mapunit.
Description of Tarrus, Moderately Eroded
Setting
Landform: Hillslopes on ridges
Landform position (two-dimensional): Backslope
Landform position (three-dimensional): Side slope
Down -slope shape: Linear
Across -slope shape: Convex
Parent material: Residuum weathered from metavolcanics and/or argillite
Typical profile
Ap - 0 to 6 inches: gravelly silty clay loam
Bt - 6 to 45 inches: silty clay
Cr - 45 to 80 inches: weathered bedrock
Properties and qualities
Slope: 8 to 15 percent
Depth to restrictive feature: 40 to 60 inches to paralithic bedrock
Drainage class: Well drained
Runoff class: Medium
Capacity of the most limiting layer to transmit water (Ksat): Very low to high (0.00
to 1.98 in/hr)
Depth to water table: More than 80 inches
Frequency of flooding: None
Frequency of ponding: None
Available water capacity. Low (about 4.5 inches)
Interpretive groups
Land capability classification (irrigated): None specified
Land capability classification (nonirrigated): 3e
Hydrologic Soil Group: B
Hydric soil rating: No
15

qiwQ-USGS
science for a changing world
U.S. DEPARTMENT OF THE INTERIOR
U.S. GEOLOGICAL SURVEY
The National Map
USTopo
WAXHAW QUADRANGLE
NORTH CAROLINA - UNION COUNTY
7.5-MINUTE SERIES
-80.7500'
35.0000' 523000ME 24 25 26 27 28 29 30 31 32 33
34.8750° 23
-80.7500°
24
Produced by the United States Geological Survey
25
North American Datum of 1983 (NAD83)
World Geodetic System of 1984 (WGS84). Projection and
1 000-meter grid: Universal Transverse Mercator, Zone 17S
This map is not a legal document. Boundaries may be
generalized for this map scale. Private lands within government
reservations may not be shown. Obtain permission before
entering private lands.
Imagery .....................................................NAIP, May 2016 - November 2016
Roads ......................................... U.S. Census Bureau, 2016
Names............................................................................GNIS, 1980 - 2019
Hydrography...............................National Hydrography Dataset, 1899 - 2018
Contours............................................National Elevation Dataset, 2008 - 2009
Boundaries ..............Multiple sources; see metadata file 2017 - 2018
Wetlands.................FWS National Wetlands Inventory 1983 - 1989
26
MN, ,
N
7*54'
140 MILS
0*11'
3 MILS
UTM GRID AND 2019 MAGNETIC NORTH
DECLINATION AT CENTER OF SHEET
U.S. National Grid
100,000 - m Square ID
NU
Grid Zone Designation
17S
27
SCALE 1:24 000
29
30
1 0.5 0 KILOMETERS 1 2
1000 500 0 METERS 1000 2000
1 0.5 0 1
MILES
1000 0 1000 2000 3000 4000 5000 6000 7000 8000 9000 10000
FEET
CONTOUR INTERVAL 10 FEET
NORTH AMERICAN VERTICAL DATUM OF 1988
This map was produced to conform with the
National Geospatial Program US Topo Product Standard, 2011.
A metadata file associated with this product is draft version 0.6.18
31
32
33
-80.6250`
34 35.0000'
73
72
71
70
69
68
67
::
65
64
63
62
61
3860000-N
53400omE
34.8750'
-80.6250'
ROAD CLASSIFICATION
Expressway Local Connector
oo 0
NORTH
AROLINA
Secondary Hwy _ Local Road;
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Ramp 4WD
P.-Y
• Interstate Route US Route O State Route
M
QUADRANGLE LOCATION
N
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1 Weddington
C9
1
2
3
2 Matthews
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3 Bakers
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4 5 4 Catawba NE cD O
5 Monroe Z
ILL
6 Van Wyck r W
6 7 8 7 Unity M
8 Tradesville WAXHAW, NC uZi
ADJOINING QUADRANGLES 2019 Z Z

NOAA Atlas 14, Volume 2, Version 3
' Location name: Waxhaw, North Carolina, USA*
Latitude: 34.9752°, Longitude:-80.7411
Elevation: m/ft**
source: ESRI Maps m y�
** source: USGS
POINT PRECIPITATION FREQUENCY ESTIMATES
G.M. Bonnin, D. Martin, B. Lin, I Parzybok, M.Yekta, and D. Riley
NOAA, National Weather Service, Silver Spring, Maryland
PF tabular I PF graphical I Maps & aerials
PF tabular
PDS-based point precipitation frequency estimates with 90% confidence intervals (in inches/hour)1
Average recurrence interval (years)
Duration ������1 100
1 2 5 10 25 50 100 200 500 1000
5.02 5.93 6.88 7.57 8.38 8.93 9.43 9.89 10.4 10.8
5-min
(4.62-5.45) (5.45-6.46) (6.31-7.49) 1 (6.94-8.22) 1 (7.64-9.08) 1 (8.11-9.67) 1 (8.53-10.2) 1 (8.89-10.7) 1 (9.28-11.3) 1 (9.53-11.7)
10-min 4.01 4.73 5.50 6.05 6.67 7.11 7.49 7.84 8.23 8.48
(3.69-4.35) (4.36-5.16) (5.05-5.99) 1 (5.55-6.58) 1 (6.09-7.24) (6.46-7.70) (6.77-8.12) 1 (7.05-8.50) (7.34-8.95) 11 (7.51-9.24)
3.34 3.97 4.64 5.11 5.64 6.00 6.32 6.59 6.91 7.10
15-min
(3.08-3.63) (3.65-4.32) (4.26-5.06) (4.68-5.54) (5.14-6.11) (5.45-6.50) 1 (5.71-6.84) 1 (5.93-7.15) (6.16-7.51) 11 (6.28-7.73)
2.29 2.74 3.30 3.70 4.18 F 4.84 5.13 5.50 5.75
30-min
(2.11-2.49) (2.52-2.99) (3.03-3.59) (3.39-4.02) (3.81-4.53) 1 (4.37-5.24) 1 (4.61-5.57) 1 (4.90-5.97) (5.09-6.26)
60-min 1.43 1.72 2.11 2.41 2.78 3.06 3.33 3.60 3.94 4.20 (1.32-1.55) 1 (1.58-1.87) (1.94-2.30) (2.21-2.62) 11 (2.54-3.01) 11 (2.78-3.32) (3.01-3.61) (3.24-3.90) (3.52-4.29) (3.71-4.57)
0.825 0.998 1.24 1.42 1.66 1.84 2.02 2.20 2.43 2.62
2-hr
(0.756-0.902) (0.914-1.09) 1 (1.13-1.35) 1 (1.29-1.55) 1 (1.50-1.81) 1 (1.66-2.00) (1.81-2.20) (1.96-2.39) (2.15-2.65) (2.29-2.86)
0.584 0.705 0.878 1.01 1.20 1.34 1.49 F 1.64 F 1.85 2.01
3-hr
(0.534-0.642) ( 0.645-0.775) ( 0.802-0.965) (0.923-1.11) 1 (1.08-1.31) (1.21-1.47) (1.33-1.62) 1 (1.46-1.79) 1 (1.62-2.02) 1 (1.75-2.20)
0.352 0.424 0.529 0.612 0.725 0.815 0.908 1.00 1.14 1.24
6-hr
(0.322-0.386) (0.389-0.465) (0.484-0.580) (0.558-0.670) (0.657-0.791) (0.735-0.888) (0.812-0.989) (0.890-1.09) (0.994-1.24) 1 (1.07-1.35)
0.206 0.249 0.312 0.363 0.434 0.491 0.550 0.613 F 0.701 0.772
12-hr
(0.190-0.227) (0.229-0.274) (0.286-0.343) (0.331-0.398) (0.393-0.473) (0.441-0.535) (0.490-0.599) (0.540-0.666) (0.607-0.761) (0.660-0.840)
0.123 0.148 0.186 0.216 0.258 0.291 0.327 0.363 0.415 0.457
24-hr
(0.113-0.133) ( 0.137-0.160) ( 0.172-0.201) ( 0.199-0.234) ( 0.237-0.279) (0.267-0.315) (0.298-0.354) (0.330-0.394) (0.375-0.451) ( 0.410-0.497)
2-day 0.072 0.087 0.108 0.125 0.149 0.168 F 0.188 0.209 0.238 0.261
F(0-
(0.067-0.078) (0.080-0.094) (0.100-0.118) (0.116-0.136) (0.137-0.162) (154-0.182 0.171-0.204) ( 0.190-0.227) ( 0.214-0.259) (0.234-0.285)
0.051 0.061 0.076 0.088 0.104 0.117 0.131 0.145 0.165 F 0.181
3-day
(0.047-0.055) (0.057-0.066) (0.070-0.082) (0.081-0.095) (0.096-0.113) (0.108-0.127) (0.120-0.142) (0.132-0.157) (0.149-0.179) (0.163-0.197)
0.040 0.049 0.060 0.069 0.082 0.092 0.102 0.113 0.129 0.141
4-day
(0.038-0.044) (0.045-0.052) (0.056-0.065) (0.064-0.074) (0.075-0.088) (0.084-0.099), (0.094-0.111) (0.103-0.123) (0.117-0.140) (0.127-0.153)
0.027 0.032 0.039 0.045 0.052 0.059 0.065 F 0.072 0.081 0.089
7-day
(0.025-0.029) (0.030-0.034) (0.036-0.042) (0.042-0.048) (0.049-0.056) (0.054-0.063) (0.060-0.070) (0.066-0.077) (0.074-0.087) ( 0.081-0.096)
F 0.026 0.031 0.035 0.040 0.045 0.049 0.054 0.060 0.065
F0.021
10-day
(0.020-0.023) (0.024-0.027) (0.029-0.033) (0.033-0.037) (0.038-0.043) (0.042-0.048) (0.046-0.053) (0.050-0.058) (0.055-0.065) (0.060-0.070)
0.014 0.017 0.020 0.022 0.026 0.028 0.031 0.034 0.037 0.040
-:d �ay
(0.013-0.015) (0.016-0.018) (0.019-0.021) (0.021-0.024) (0.024-0.027) (0.026-0.030) (0.029-0.033) (0.031-0.036) (0.034-0.040) (0.037-0.043)
0.012 0.014 0.016 0.018 0.020 0.022 0.024 0.025 0.028 0.030
30-day
(0.011-0.012) (0.013-0.015) (0.015-0.017) (0.017-0.019) (0.019-0.021) (0.021-0.023) (0.022-0.025) (0.024-0.027) (0.026-0.030) (0.027-0.032)
0.010 0.012 0.013 0.014 0.016 0.017 0.019 0.020 0.021 0.023
45-day
(0.009-0.010) (0.011-0.012) (0.012-0.014) (0.014-0.015) (0.015-0.017) (0.016-0.018) (0.018-0.020) (0.019-0.021) (0.020-0.023) (0.021-0.024)
0.009 0.010 0.012 0.013 0.014 0.015 0.016 0.017 0.018 0.019
60-day
(0.008-0.009) (0.010-0.011) (0.011-0.012) (0.012-0.013) (0.013-0.015) (0.014-0.016) (0.015-0.017) (0.016-0.018) (0.017-0.019) (0.018-0.020)
Precipitation frequency (PF) estimates in this table are based on frequency analysis of partial duration series (PDS).
Numbers in parenthesis are PF estimates at lower and upper bounds of the 90% confidence interval. The probability that precipitation frequency estimates (for a
given duration and average recurrence interval) will be greater than the upper bound (or less than the lower bound) is 5%. Estimates at upper bounds are not
checked against probable maximum precipitation (PMP) estimates and may be higher than currently valid PMP values.
Please refer to NOAA Atlas 14 document for more information.
Back to Top
PF graphical

NOAA Atlas 14, Volume 2, Version 3
' Location name: Waxhaw, North Carolina, USA*
Latitude: 34.9752°, Longitude:-80.7411
Elevation: m/ft**
source: ESRI Maps m y�
** source: USGS
POINT PRECIPITATION FREQUENCY ESTIMATES
G.M. Bonnin, D. Martin, B. Lin, I 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)'
Average recurrence interval (years)
Duration 100 1 �����
2 5 10 25 50 200 500 1000
5-min 0.418 0.494 0.573 0.631 0.698 0.744 0.786 0.824IF 0.867 IF 0.898
(0.385-0.454) (0.454-0.538) (0.526-0.624) (0.578-0.685) (0.637-0.757) (0.676-0.806) (0.711-0.852) (0.741-0.894) (0.773-0.943) (0.794-0.978)
10-min 0.668 0.789 0.917 1.01 1.11 1.19 1.25 1.31 1.37 F 1.41
(0.615-0.725) (0.726-0.860) (0.842-0.999) (0.925-1.10) 1 (1.01-1.21) 1 (1.08-1.28) 1 (1.13-1.35) 1 (1.18-1.42) 1 (1.22-1.49) 1 (1.25-1.54)
0.835
0.992
1.16
15-min
(0.769-0.907)
(0.913-1.08)
1 (1.07-1.26)
1.14
1.37
1.65
30-min
(1.06-1.24)
1 (1.26-1.49)
1 (1.51-1.80)
1.28
1.41
1.50
1.58
1.65
1.73
1.78
(1.17-1.39) 11
(1.29-1.53)
1 (1.36-1.63)
1 (1.43-1.71)
1 (1.48-1.79)
1.85
2.09
2.26
2.42
2.57
2.75
2.88
(1.70-2.01)
1 (1.91-2.26)
11 (2.05-2.45)
1 (2.19-2.62)
1 (2.31-2.78)
(2.45-2.99)1
(2.54-3.13)
60-min 1.43 1.72 2.11 2.41 2.78 3.06 3.33 3.60 3.94 4.20
(1.32-1.55) (1.58-1.87) (1.94-2.30) (2.21-2.62) 11 (2.54-3.01) 11 (2.78-3.32) 1 (3.01-3.61) 1 (3.24-3.90) 1 (3.52-4.29) 1 (3.71-4.57)
2-hr 1.65 2.00 2.47
(1.51-1.81) (1.83-2.19) (2.26-2.71)
3-hr 1.75 2.12 2.64
(1 .60-1.93) (1.94-2.33) (2.41-2.90)
2.84
3.31
3.67
4.03
4.39
4.87
5.23
(2.58-3.10)
1 (3.00-3.61)
1 (3.32-4.00)
1 (3.62-4.39)
1 (3.92-4.79)
1 (4.30-5.31)
(4.58-5.71)
3.05
3.59
4.03
4.47
4.93
5.55
6.05
(2.77-3.34)
(3.25-3.93)
(3.63-4.40)
(4.00-4.87)
(4.37-5.37)
(4.86-6.06)
1 (5.24-6.61)
6-hr 2.11 2.54 3.17 3.67 4.34 4.88 5.44 6.02 6.82 7.45
(1.93-2.31) 1 (2.33-2.79) 1 (2.90-3.48) 1 (3.34-4.01) 1 (3.94-4.74) 1 (4.40-5.32) 1 (4.87-5.92) 1 (5.33-6.54) 1 (5.95-7.41) 1 (6.43-8.10)
12-hr 2.49 3.00 3.76
(2.29-2.73) 1 (2.76-3.30) 1 (3.45-4.13)
24-hr 2.94 3.55 4.46
(2.72-3.18) (3.29-3.85) (4.12-4.83)
4.37
5.22
5.91
6.63
7.38
8.44
9.31
(3.99-4.79)
1 (4.73-5.70)
1 (5.31-6.44)
1 (5.90-7.21)
1 (6.50-8.03)
1 (7.32-9.17)
1 (7.96-10.1)
8.72
9.96
11.0
5.18
6.18
6.99
7.84
(4.78-5.61)
1 (5.68-6.69)
1 (6.41-7.57)
1 (7.15-8.49)
1 (7.92-9.46)
1 (8.99-10.8)
1 (9.84-11.9)
2-day 3.46 4.17 5.20 6.02 7.16 8.08 9.02 10.0 11.4 12.5
(3.21-3.76) 1 (3.86-4.53) 1 (4.81-5.65) 1 (5.55-6.53) 1 (6.58-7.76) 1 (7.40-8.76) 1 (8.23-9.80) 1 (9.10-10.9) 1 (10.3-12.4) 1 (11.2-13.7)
3-day 3.67 4.41 5.48 6.32 7.50 8.44 F 9.42 10.4 11.9 13.0
(3.41-3.97) fl (4.10-4.78) 1 (5.07-5.93) 1 (5.84-6.84) 1 (6.90-8.11) 1 (7.75-9.14) 1 (8.61-10.2) 1 (9.51-11.3) 1 (10.7-12.9) 1 (11.7-14.2)
4-day 3.88 4.66 5.75 6.62 7.83 8.81 9.81 10.9 1213.5
(3.61-4.19) (4.33-5.03) (5.34-6.21) (6.13-7.15) (7.23-8.46) (8.10-9.52) 11 (9.00-10.6) (9.92-11.8) (.3 11.2-13.4) (12.2-14.7)
7-day 4.50 5.37 6.54 7.48
(4.20-4.83) (5.02-5.76) 1 (6.11-7.02) 1 (6.98-8.02)
�-7 5.14 6.12 7.37 8.36
(4.83-5.51) fl (5.73-6.55) 1 (6.89-7.88) 1 (7.80-8.93)
8.79
(8.16-9.42)
(9.02-10.4)
9.83
10.9 12.0
13.6
14.9
1 (9.10-10.5)
1 (10.1-11.7) 1 (11.1-12.9)
1 (12.4-14.7)
(13.5-16.1)
9.69
10.7
11.8
12.9
14.4
15.7
1 (9.99-11.5)
1 (11.0-12.7)
1 (11.9-13.9)
1 (13.3-15.5)
20-day 6.88 8.11 9.58 10.8 12.3 13.6 14.8 16.1 17.8 19.2
(6.47-7.32) (7.64-8.65) (9.01-10.2) (10.1-11.5) (11.5-13.1) (12.7-14.5) (13.8-15.8) 1 (15.0-17.2) 1 (16.5-19.1) (17.7-20.6)
30-day 8.43 9.92 11.5 12.8 14.5 15.8 17.0 18.3 20.0 21.3
(7.97-8.95) (9.37-10.5) (10.9-12.3) (12.1-13.6) (13.6-15.4) (14.8-16.7) (15.9-18.1) 1 (17.1-19.5) 1 (18.6-21.3)
45-day 10.6 12.4 14.2 15.6 17.4 18.8 20.1 F 21.4 23.1 24.4
(10.1-11.2) (11.8-13.1) (13.5-15.0) (14.8-16.4) (16.5-18.3) (17.7-19.8) (19.0-21.2) (20.2-22.6) (21.7-24.4) (22.8-25.8)
60-day (12.0-13.2) (14.0- 5.4) (15.9-17.5) (17.18 9.0) (19.1021.1) (20.51 2.6) (21.8--4.1) (23?0- 5.6) (246627.5) (25?8- 8.9)
1 Precipitation frequency (PF) estimates in this table are based on frequency analysis of partial duration series (PDS).
Numbers in parenthesis are PF estimates at lower and upper bounds of the 90% confidence interval. The probability that precipitation frequency estimates (for a
given duration and average recurrence interval) will be greater than the upper bound (or less than the lower bound) is 5%. Estimates at upper bounds are not
checked against probable maximum precipitation (PMP) estimates and may be higher than currently valid PMP values.
Please refer to NOAA Atlas 14 document for more information.
Back to Top
PF graphical

LITTLE"
DIVERSIFIED ARCHITECTURAL CONSULTING
STORM DRAINAGE SYSTEM
615 South College Street, Suite 1600 1 Charlotte, North Carolina 28202 1 p: 704.525.6350 1 www.litLleonline.com

\ tZ--
I
OVERALL SITE AREA = 15.59 AC
IMPERVIOUS AREA = 1.82 AC
BUA % = 11.7%

-71
I i CURB FLUME-1
I I DA: .56
22
C: 0.76
I I Q 3.21
I I 1
CURB FLUME-2
\ I 1 \ \ DA: .16
Q 0.89 1
Q .08
\ \ CURB FLUME-3 CURB FLUME-4
DA: 0.21 DA: 045
0.76 Q 0..89
Q 1.21 +3.03=4.24
\ Q 3.03
\\ \ \ \ \ CURB FLUME-5 �` \
� DA 0.20
\ C. 0.76
Q 1.15+L21 +3.03=5.39
\ \\ \ \ \ AD-106.18 AD-106.19 DI-102.2 I DI-102.3
\ DA: 0.04 DA: 0.01 DA: 0.06 DA: 0.06
�\\ \E BsJIL ING
FNT�N
Spy00` 4N0 40&P11
Opp RTSO
� � DI-zo1 � F SCyOp� NCH
DA: 0.45
C: 0.30
1

Hydraflow Storm Sewers Extension for Autodesk@ Civil 3D@ Plan
Outfall
1
Project File: 200 Series.stm Number of lines: 1 Date: 2/10/2021
Storm Sewers v2020.00

MyReport
Page 1
Line
No.
Inlet
ID
Line
Size
(in)
Line
Length
(ft)
Line
Slope
M
Invert
Up
(ft)
Invert
Dn
(ft)
Gnd/Rim
El Up
(ft)
Drng
Area
(ac)
Runoff
Coeff
(C)
Flow
Rate
(cfs)
Incr
Q
(cfs)
Known
Q
(cfs)
Vel
Dn
(ft/s)
Capac
Full
(cfs)
1
DI-201
15
65
0.77
569.50
569.00
573.95
0.45
0.30
0.98
0.98
0.00
2.99
6.15
Project File: 200 Series.stm
Number of lines: 1
Date: 2/10/2021
NOTES: "Critical depth
Storm Sewers

Hydraulic Grade Line Computations
Page 1
Line
Size
(in)
Q
(cfs)
Downstream
Len
(ft)
Upstream
Check
JL
coeff
(K)
Minor
loss
(ft)
Invert
elev
(ft)
HGL
elev
(ft)
Depth
(ft)
Area
(sgft)
Vel
(ft/s)
Vel
head
(ft)
EGL
elev
(ft)
Sf
M
Invert
elev
(ft)
HGL
elev
(ft)
Depth
(ft)
Area
(sgft)
Vel
(ft/s)
Vel
head
(ft)
EGL
elev
(ft)
Sf
M
Ave
Sf
M
Enrgy
loss
(ft)
1
15
0.98
569.00
569.39
0.39
0.32
2.99
0.14
569.53
0.000
65
569.50
569.89 j
0.39**
0.32
3.01
0.14
570.03
0.000
0.000
n/a
1.00
n/a
Project File: 200 Series.stm
Number of lines: 1
Run Date: 2/10/2021
Notes: ; ** Critical depth.; j-Line contains hyd. jump ; c = cir e = ellip b = box
Storm Sewers v2020.00

Hydraflow HGL Computation Procedure
Page 1
General Procedure:
Hydraflow computes the HGL using the Bernoulli energy equation. Manning's equation is used to determine energy losses due to pipe friction.
In a standard step, iterative procedure, Hydraflow assumes upstream HGLs until the energy equation balances. If the energy equation
cannot balance, supercritical flow exists and critical depth is temporarily assumed at the upstream end. A supercritical flow Profile
is then computed using the same procedure in a downstream direction using momentum principles.
Col. 1 The line number being computed. Calculations begin at Line 1 and proceed upstream.
Col. 2 The line size. In the case of non -circular pipes, the line rise is printed above the span.
Col. 3 Total flow rate in the line.
Col. 4 The elevation of the downstream invert.
Col. 5 Elevation of the hydraulic grade line at the downstream end. This is computed as the upstream HGL + Minor loss of this line's downstream line.
Col. 6 The downstream depth of flow inside the pipe (HGL - Invert elevation) but not greater than the line size.
Col. 7 Cross -sectional area of the flow at the downstream end.
Col. 8 The velocity of the flow at the downstream end; (Col. 3 / Col. 7).
Col. 9 Velocity head (Velocity squared / 2g).
Col. 10 The elevation of the energy grade line at the downstream end, HGL + Velocity head, (Col. 5 + Col. 9).
Col. 11 The friction slope at the downstream end (the S or Slope term in Manning's equation).
Col. 12 The line length.
Col. 13 The elevation of the upstream invert.
Col. 14 Elevation of the hydraulic grade line at the upstream end.
Col. 15 The upstream depth of flow inside the pipe (HGL - Invert elevation) but not greater than the line size.
Col. 16 Cross -sectional area of the flow at the upstream end.
Col. 17 The velocity of the flow at the upstream end; (Col. 3 / Col. 16).
Col. 18 Velocity head (Velocity squared / 2g).
Col. 19 The elevation of the energy grade line at the upstream end, HGL + Velocity head, (Col. 14 + Col. 18) .
Col. 20 The friction slope at the upstream end (the S or Slope term in Manning's equation).
Col. 21 The average of the downstream and upstream friction slopes.
Col. 22 Energy loss. Average Sf/100 x Line Length (Col. 21/100 x Col. 12). Equals (EGL upstream - EGL downstream) +/- tolerance.
Col. 23 The junction loss coefficient (K).
Col. 24 Minor loss. (Col. 23 x Col. 18). Is added to upstream HGL and used as the starting HGL for the next upstream line(s).

Storm Sewer Profile
Proj. file: 200 Series.stm
(ft)
N O
O �j O
O
o w
+O -o W
cu E
DI -201 to
M-200
T
—j O
^_ OO
O Cho
n LO
COElev.
�'
+O w W
B 9;
cn �
582.00
582.00
579.00
579.00
576.00
576.00
573.00
573.00
570.00
567.00
0
0 10 20 30 40 50
HGL Reach (ft)
570.00
567.00
60 70 80 90 100
Storm Sewers

Channel Report
Hydraflow Express Extension for Autodesk® Civil 3D® by Autodesk, Inc.
Curb Flume-6 to FES-101
Trapezoidal
Bottom Width (ft)
= 15.00
Side Slopes (z:1)
= 5.00, 5.00
Total Depth (ft)
= 1.00
Invert Elev (ft)
= 568.00
Slope (%)
= 0.50
N-Value
= 0.030
Calculations
Compute by:
Known Q
Known Q (cfs)
= 3.20
Elev (ft)
570.00
v
569.50
569.00
568.50
568.00
567.50
Section
1 5 10 15 20
Reach (ft)
Highlighted
Depth (ft)
Q (cfs)
Area (sqft)
Velocity (ft/s)
Wetted Perim (ft)
Crit Depth, Yc (ft)
Top Width (ft)
EGL (ft)
25 30
Tuesday, Apr 27 2021
= 0.19
= 3.200
= 3.03
= 1.06
= 16.94
= 0.12
= 16.90
= 0.21
Depth (ft)
2.00
1.50
1.00
0.50
-0.50
35

Channel Report
Hydraflow Express Extension for Autodesk® Civil 3D® by Autodesk, Inc.
Sidewalk Culvert
Circular
Diameter (ft) = 1.50
Invert Elev (ft) = 570.00
Slope (%) = 0.50
N-Value = 0.013
Calculations
Compute by: Known Q
Known Q (cfs) = 5.11
Elev (ft)
572.00
571.50
571.00
570.50
570.00
569.50
Highlighted
Depth (ft)
Q (cfs)
Area (sqft)
Velocity (ft/s)
Wetted Perim (ft)
Crit Depth, Yc (ft)
Top Width (ft)
EGL (ft)
Section
Tuesday, Apr 20 2021
= 0.92
= 5.110
= 1.14
= 4.49
= 2.70
= 0.87
= 1.46
= 1.23
0 1 2 3
Reach (ft)

Channel Report
Hydraflow Express Extension for Autodesk® Civil 3D® by Autodesk, Inc.
Channel at FES-100
Trapezoidal
Bottom Width (ft)
= 0.50
Side Slopes (z:1)
= 3.00, 3.00
Total Depth (ft)
= 5.00
Invert Elev (ft)
= 563.40
Slope (%)
= 1.67
N-Value
= 0.034
Calculations
Compute by:
Known Q
Known Q (cfs)
= 7.40
Highlighted
Depth (ft)
Q (cfs)
Area (sqft)
Velocity (ft/s)
Wetted Perim (ft)
Crit Depth, Yc (ft)
Top Width (ft)
EGL (ft)
Tuesday, Apr 27 2021
= 0.81
= 7.400
= 2.37
= 3.12
= 5.62
= 0.75
= 5.36
= 0.96
Elev (ft) Section Depth (ft)
569.00
5.60
568.00
4.60
567.00
3.60
566.00
2.60
1.60
565.00
564.00
0.60
563.00
562 00
-0.40
1 40
5 10 15 20 25
Reach (ft)
30 35 40 45

LITTLE"
DIVERSIFIED ARCHITECTURAL CONSULTING
CURB FLUMES
615 South College Street, Suite 1600 1 Charlotte, North Carolina 28202 1 p: 704.525.6350 1 www.litLleonline.com

Weir Report
Hydraflow Express Extension for Autodesk® Civil 3D® by Autodesk, Inc.
Curb Flume-1
Rectangular Weir
Crest
= Sharp
Bottom Length (ft)
= 3.00
Total Depth (ft)
= 0.50
Calculations
Weir Coeff. Cw
= 3.33
Compute by:
Known Q
Known Q (cfs)
= 3.22
Depth (ft)
1.00
0.50
NMI
-0.50
Curb Flume-1
Highlighted
Depth (ft)
Q (cfs)
Area (sqft)
Velocity (ft/s)
Top Width (ft)
Tuesday, Apr 20 2021
= 0.47
= 3.220
= 1.41
= 2.28
= 3.00
Depth (ft)
1.00
0.50
-0.50
0 .5 1 1.5 2 2.5 3 3.5 4
Weir W.S. Length (ft)

Weir Report
Hydraflow Express Extension for Autodesk® Civil 3D® by Autodesk, Inc.
Curb Flume-2
Rectangular Weir
Crest
= Sharp
Bottom Length (ft)
= 2.00
Total Depth (ft)
= 0.50
Calculations
Weir Coeff. Cw
= 3.33
Compute by:
Known Q
Known Q (cfs)
= 1.08
Depth (ft)
1.00
0.50
NMI
-0.50
Curb Flume-2
Highlighted
Depth (ft)
Q (cfs)
Area (sqft)
Velocity (ft/s)
Top Width (ft)
Tuesday, Apr 20 2021
= 0.30
= 1.080
= 0.59
= 1.82
= 2.00
Depth (ft)
1.00
0.50
-0.50
0 .5 1 1.5 2 2.5 3
Weir W.S. Length (ft)

Weir Report
Hydraflow Express Extension for Autodesk® Civil 3D® by Autodesk, Inc.
Curb Flume-3
Rectangular Weir
Highlighted
Crest
= Sharp
Depth (ft)
Bottom Length (ft)
= 1.50
Q (cfs)
Total Depth (ft)
= 0.50
Area (sqft)
Velocity (ft/s)
Calculations
Top Width (ft)
Weir Coeff. Cw
= 3.33
Compute by:
Known Q
Known Q (cfs)
= 1.21
Depth (ft)
1.00
0.50
NMI
-0.50
0 .5 1
Weir W.S.
Curb Flume-3
Tuesday, Apr 20 2021
= 0.39
= 1.210
= 0.58
= 2.08
= 1.50
Depth (ft)
1.00
0.50
-0.50
1.5 2 2.5
Length (ft)

Weir Report
Hydraflow Express Extension for Autodesk® Civil 3D® by Autodesk, Inc.
Curb Flume-4
Rectangular Weir
Crest
= Sharp
Bottom Length (ft)
= 3.00
Total Depth (ft)
= 0.50
Calculations
Weir Coeff. Cw
= 3.33
Compute by:
Known Q
Known Q (cfs)
= 3.03
Depth (ft)
1.00
0.50
NMI
-0.50
Curb Flume-4
Highlighted
Depth (ft)
Q (cfs)
Area (sqft)
Velocity (ft/s)
Top Width (ft)
Tuesday, Apr 20 2021
= 0.45
= 3.030
= 1.35
= 2.24
= 3.00
Depth (ft)
1.00
0.50
-0.50
0 .5 1 1.5 2 2.5 3 3.5 4
Weir W.S. Length (ft)

Weir Report
Hydraflow Express Extension for Autodesk® Civil 3D® by Autodesk, Inc.
Curb Flume-5
Rectangular Weir
Crest
Bottom Length (ft)
Total Depth (ft)
Calculations
Weir Coeff. Cw
Compute by:
Known Q (cfs)
Depth (ft)
1.00
0.50
NMI
-0.50
= Sharp
= 5.00
= 0.50
= 3.33
Known Q
= 5.39
Curb Flume-5
Highlighted
Depth (ft)
Q (cfs)
Area (sqft)
Velocity (ft/s)
Top Width (ft)
Tuesday, Apr 20 2021
= 0.47
= 5.390
= 2.36
= 2.29
= 5.00
0 1 2 3 4 5 6 7
Depth (ft)
1.00
0.50
-0.50
Weir W.S.
Length (ft)

Weir Report
Hydraflow Express Extension for Autodesk® Civil 3D® by Autodesk, Inc.
Curb Flume-6
Rectangular Weir
Crest
= Sharp
Bottom Length (ft)
= 3.00
Total Depth (ft)
= 0.50
Calculations
Weir Coeff. Cw
= 3.33
Compute by:
Known Q
Known Q (cfs)
= 3.20
Depth (ft)
1.00
0.50
NMI
-0.50
Curb Flume-6
Highlighted
Depth (ft)
Q (cfs)
Area (sqft)
Velocity (ft/s)
Top Width (ft)
Tuesday, Apr 27 2021
= 0.47
= 3.200
= 1.40
= 2.28
= 3.00
Depth (ft)
1.00
0.50
-0.50
0 .5 1 1.5 2 2.5 3 3.5 4
Weir W.S. Length (ft)

LITTLE"
DIVERSIFIED ARCHITECTURAL CONSULTING
RIPRAP APRONS
615 South College Street, Suite 1600 1 Charlotte, North Carolina 28202 1 p: 704.525.6350 1 www.littleonline.com

Riprap Outlet Protection: HW-200
Outlet Information
Outlet Pipe Diameter (Do) = 15 in
Tailwater Depth = 0 in
Min. or Max. Tailwater? Min. TW (Fig. 8.06a)
Discharge (Q) = 1 cfs
Riprap Apron
Riprap Size (d5o) = 0.50 ft (from figure)
Min. Apron Length (La) = 8.0 ft (from figure)
Apron Width at Pipe Outlet = 3 * Do = 3.750 ft
Apron Width at Outlet End = Do + La = 9.25 ft
Max. Stone Diameter, dmax =1.5 * d5o = 0.75 ft
Apron Thickness = 1.5 * dmax = 1.125 ft
Legend
red = input
black = calculation

Figure 8.06a: Design of outlet protection from a round pipe flowing full, minimum tailwater
condition (TW < 0.5 diameter)
I zo
=8ft to
3 0
Outlet W . Do + La
pipe I
diameter PD)
La
T il►later 0.5Do
1
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Riprap Outlet Protection: FES-100
Outlet Information
Outlet Pipe Diameter (Do) = 15 in
Tailwater Depth = 0 in
Min. or Max. Tailwater? Min. TW (Fig. 8.06a)
Discharge (Q) = 5 cfs
Riprap Apron
Riprap Size (d5o) = 0.50 ft (from figure)
Min. Apron Length (La) = 8.0 ft (from figure)
Apron Width at Pipe Outlet = 3 * Do = 3.750 ft
Apron Width at Outlet End = Do + La = 9.25 ft
Max. Stone Diameter, dmax =1.5 * d5o = 0.75 ft
Apron Thickness = 1.5 * dmax = 1.125 ft
Legend
red = input
black = calculation

Figure 8.06a: Design of outlet protection from a round pipe flowing full, minimum tailwater
condition (TW < 0.5 diameter)
3 0
Outlet W . Do + L
Pipe I
diameter PD)
La
-,A,, 1 water � 0.5Do
p1 Pp 60 —
9`r
men
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L" = 8 ft

Riprap Outlet Protection: RL @ Front of Building
Outlet Information
Outlet Pipe Diameter (Do) = 12 in
Tailwater Depth = 0 in
Min. or Max. Tailwater? Min. TW (Fig. 8.06a)
Discharge (Q) = 1 cfs
Riprap Apron
Riprap Size (d5o) = 0.50 ft (from figure)
Min. Apron Length (La) = 6.0 ft (from figure)
Apron Width at Pipe Outlet = 3 * Do = 3.000 ft
Apron Width at Outlet End = Do + La = 7.00 ft
Max. Stone Diameter, dmax =1.5 * d5o = 0.75 ft
Apron Thickness = 1.5 * dmax = 1.125 ft
Legend
red = input
black = calculation

Figure 8.06a: Design of outlet protection from a round pipe flowing full, minimum tailwater
condition (TW < 0.5 diameter)
20
L.. = 6 ft 10
3 0
Outlet W . Do + La
pipe I
diameter PD)
La
T il►later 0.5Do
1
60
51
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Riprap Outlet Protection: Rainchains
Outlet Information
Outlet Pipe Diameter (Do) = 12 in
Tailwater Depth = 0 in
Min. or Max. Tailwater? Min. TW (Fig. 8.06a)
Discharge (Q) = 2 cfs
Riprap Apron
Riprap Size (d5o) = 0.50 ft (from figure)
Min. Apron Length (La) = 6.0 ft (from figure)
Apron Width at Pipe Outlet = 3 * Do = 3.000 ft
Apron Width at Outlet End = Do + La = 7.00 ft
Max. Stone Diameter, dmax =1.5 * d5o = 0.75 ft
Apron Thickness = 1.5 * dmax = 1.125 ft
Legend
red = input
black = calculation

Figure 8.06a: Design of outlet protection from a round pipe flowing full, minimum tailwater
condition (TW < 0.5 diameter)
20
L.. = 6 ft 10
3 0
Outlet W . Do + La
pipe I
diameter PD)
La
T il►later 0.5Do
1
60
51
.; II
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Riprap Outlet Protection: RL @ Side & Back of Building
Outlet Information
Outlet Pipe Diameter (Do) = 1" in
Tailwater Depth = in
Min. or Max. Tailwater? Min. TW (Fig. 8.06a)
Discharge (0.) = cfs
Riprap Apron
Riprap Size (d50) = 0.50 ft (from figure)
Min. Apron Length (La) = 6.0 ft (from figure)
Apron Width at Pipe Outlet = 3 * Do = 3.000 ft
Apron Width at Outlet End = Do + La = 7.00 ft
Max. Stone Diameter, dmax = 1.5 * d50 = 0.75 ft
Apron Thickness = 1.5 * dmax = 1.125 ft
Legend
red = input
black = calculation

Figure 8.06a: Design of outlet protection from a round pipe flowing full, minimum tailwater
condition (TW < 0.5 diameter)
20
L.. = 6 ft 10
3 0
Outlet W . Do + La
pipe I
diameter PD)
La
T il►later 0.5Do
1
60
51
.; II
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LITTLE"
DIVERSIFIED ARCHITECTURAL CONSULTING
SKIMMER SEDIMENT BASINS
615 South College Street, Suite 1600 1 Charlotte, North Carolina 28202 1 p: 704.525.6350 1 www.litLleonline.com

Skimmer Sediment Basin #1 Design
Basin Storage
Drainage Area, A = 2.50 acres
Storage Required = 3,600 * A = 9,000 ft,
Basin Size (Refer to Erosion Control
Plan)
Elevation
Area (ft Z)
Cumulative Volume (ft 3)
552.00
941
0
553.00
1592
1267
554.00
2615
3370
555.00
3163
6259
556.00
3737
9709
Basin Configuration
Bottom Elevation =
552.00
Spillway Elevation =
556.00
Top of Berm Elevation =
557.50
Proposed Sediment Depth =
4.00 ft
Basin Efficiency
Basin Storage Required = 9,000 ft,
Basin Storage Provided = 9,709 ft' So, good design
Surface Area Required = 325 ftZ/cfs = 3,690 ftz
Surface Area Provided = 3,737 ft' So, good design
Skimmer Design (One Skimmer)
Drawdown Time = 2.00 days
Skimmer Size = 2.5 inches
Orifice Size = 2.3 inches
Faircloth Skimmer Design Table
Skimmer Size (in)
Volume Drained (ft )
Factor
1.5
3456
1920
2
6566
2246
2.5
11000
2304
3
19547
2765
4
36534
2908
5
65664
3283
6
103680
3628
8
195956
3974
Spillway Design Flow
Composite Soil Coefficient, C = 0.60 (Bare Soil)
Drainage Area, A = 2.50 acres
10-year Rainfall Intensity, Ito = 7.57 in/hr
Flow, Q = CIA = 11 cfs
Spillway Size
C = 3.0
Height of Flow Over Spillway, h = 0.5 ft
Spillway Length, L = Q / (C * h1-5) = 11 ft
Legend
red = input
black = calculation

Skimmer Sediment Basin #2 Design
Basin Storage
Drainage Area, A = 2.90 acres
Storage Required = 3,600 * A = 10,440 ft'
Basin Size (Refer to Erosion Control
Plan)
Elevation
Area (ft')
Cumulative Volume (ft 3)
555.00
372
0
556.00
947
660
557.00
1720
1993
558.00
2529
4118
559.00
3406
7085
560.00
4363
11010
Basin Configuration
Bottom Elevation =
562.00
Spillway Elevation =
566.00
Top of Berm Elevation =
567.50
Proposed Sediment Depth =
4.00 ft
Basin Efficiency
Basin Storage Required = 10,440 ft'
Basin Storage Provided = 11,010 ft, So, good design
Surface Area Required = 325 ft2/cfs = 4,281 ft'
Surface Area Provided = 4,363 ft' So, good design
Skimmer Design (One Skimmer)
Drawdown Time = 2.00 days
Skimmer Size = 3.0 inches
Orifice Size = 2.3 inches
Faircloth Skimmer Design Table
Skimmer Size (in)
Volume Drained (ft )
Factor
1.5
3456
1920
2
6566
2246
2.5
11000
2304
3
19547
2765
4
36534
2908
5
65664
3283
6
103680
3628
8
195956
3974
Spillway Design Flow
Composite Soil Coefficient, C = 0.60 (Bare Soil)
Drainage Area, A = 2.90 acres
10-year Rainfall Intensity, I10 = 7.57 in/hr
Flow, Q = CIA = 13 cfs
Spillway Size
C = 3.0
Height of Flow Over Spillway, h = 0.5 ft
Spillway Length, L = Q / (C * h15)= 12 ft
Legend
red = input
black = calculation