SW6240705_Stormwater Report_20241029

' Harnett
--"In COUNTY 1-)�
NORTH CAROLINA
strong roots • new growth
' e+ 'F Stormwater Permit
'0 y7.
`-��� � � . Application
. \ ., -
• Harnett County Northwest Convenience Center
4 PID 050634 0019 03
\.-
• w;
'lb Harnett County, North Carolina
_ . y Ma 2024
„�.
•, Revised October 2024
, . 411100_' --- / .. _
` fir_ �tt ."'- L i 04V,51 -
4 ~ • Sri"t'`, < ' ''
rlin\\\
102_,0lz9

This page intentionally left blank.

Harnett County Northwest Convenience Center I Stormwater Permit Application—October 2024 r)�
Contents
Contents
Contents i
A. Project Narrative 1
1. Existing Conditions 1
2. Proposed Site Plan 1
B. Stormwater Flows 1
1. Pre-Development Conditions 2
2. Post-Development Conditions 2
C. Wet Pond Design 3
Attachments
Attachment A— USGS Plan
Attachment B —Soil Survey Report
Attachment C— Precipitation Frequency Data
Attachment D — Stormwater Flow
Attachment D.1 — Pre-Development Calculations
Attachment D.2— Post-Development Calculations
Attachment E —Wet Pond Calculations
Attachment E.1 —Wet Pond Design Calculations
Attachment E.2 — NCDEQ SCM C-3 Wet Pond
Attachment E.3—Wet Pond Operation and Maintenance Agreement
Attachment F — Property Deed and Boundary Plan

Harnett County Northwest Convenience Center I Stormwater Permit Application—October 2024 r)�
Contents
This page intentionally left blank.

Harnett County Northwest Convenience Center I Stormwater Permit Application—October 2024
Project Narrative
A. Project Narrative
Harnett County General Services is proposing to construct a new solid waste convenience center
to be located on a parcel off Oakridge River Road in Fuquay Varina, North Carolina. The parcel
is identified by PID 050634 0019 03 and PIN 0634-54-0565 and is currently owned by Harnett
County. The total site acreage is 28.26, see Attachment A for the site location on USGS map. A
boundary survey was completed by Benton W. Dewar and Associates and has been incorporated
into the application drawings. A copy of the Deed and Boundary Plan is included as Attachment
F. The County is finalizing a Site Plan Permit and Driveway Permit and has obtained an Erosion
and Sediment Control Permit (HARNE-2023-070)from NCDEQ for the proposed construction. In
the future, the County may locate a recreational facility and parking area at the site, but this work
is not included in this application and would be subject to erosion and sediment control and post-
construction stormwater permitting.
1 . Existing Conditions
The existing site is currently undeveloped and has been used for timber plots and agricultural
purposes in the past. The site soils consist of Bibb soils, Cecil fine sandy loam, Dothan loamy
sand, Fuquay loamy sand, Pacolet fine sandy loam, and Wehadkee loam (Attachment B).
The property is located within the Avents Creek — Cape Fear River subwatershed of the Cape
Fear River Basin. Avents Creek is classified as a WS-IV;HQW stream and therefore a Post-
Construction Stormwater Permit is required. Avents Creek is located approximately 1,850 feet
through vegetated (forested) buffer from the proposed Wet Pond stormwater control device.
2. Proposed Site Plan
Upon entering the parcel via Oakridge Road, a solid waste convenience center will be located on
the left. The solid waste convenience center will consist of over the wall drop off C & D, and two
MSW containers with back-in unloading stalls. An at grade recycling container will be located
opposite of the unloading stalls with a drive-thru drop-off lane. To the right of the entrance, will be
a future multi-use athletic field with parking areas and support facilities to be constructed during
a future phase of the project.
The proposed development of the convenience center will include disturbance of 5.88 acres or
21% of the County site, with 1.63 acres of Built Upon Area (BUA). The proposed BUA is The
impervious areas consist of paved driveway entrance, gravel roadways and parking areas,
concrete pads for materials and roll-off container storage and building roof from the attendant
shelter (100 SF).
B. Stormwater Flows
Stormwater run-off rates and volumes were analyzed for the pre- and post-development
conditions using HydroCADTM modeling software program. The SCS Method was used within
the model to calculate the peak runoff and an IDF curve was generated from precipitation data
gathered at Erwin station from the NOAA Precipitation Frequency Data Server (Attachment C).
The peak flows for the 1 and 25-year, 24-hour storm events were generated by the model. The

Harnett County Northwest Convenience Center I Stormwater Permit Application—October 2024
Stormwater Flows
modeling was completed for the immediate 26.5-acre area of the site that discharges to the
wooded areas upgradient of Avent Creek.
Drainage areas for pre-development and post-development conditions were delineated from the
site along with each respective time of concentration. These acreages, time values, and
corresponding land cover were entered into the model. The stormwater control measure (wet
pond and drainage swales) were modeled using the reaches and ponds within HydroCADTM
SCM specifics including surface area, outlet dimensions, elevations, and slopes were entered
into the model. The SCM devices were assigned their corresponding drainage areas to depict
how runoff would flow on site as shown on the routing diagram of the post-development
HydroCADTM report.
The two point of analysis for the pre- and post- development flows is the existing ravine on site
located to the southwest of the proposed stormwater management are and to a low area located
on the southern side of the property line as shown on figure in Attachment D.
1 . Pre-Development Conditions
The existing site is currently undeveloped that is mostly wooded with an existing agricultural field
adjacent to Oakridge River Road. The high point of the property is located along the northern
property line and slopes downward towards the southwest corner of the property. There are
currently no stormwater management devices located onsite. For analysis purposes, four
drainage areas were delineated and analyzed for pre-development conditions (Figure 1). Runoff
generated from the western portion of the site, delineated as Areas 1 and 2, flows off-site to the
southwest into an existing ravine and eventually into Avents Creek. Flow from the southeastern
portion of the site (Area 3) discharges to the south property line and into a ravine off-site and
eventually into Avents Creek. Flow from the central and eastern portion of the site, Area 4,
discharge toward Oakridge River Road and is intercepted by an existing drainage ditch that flows
off-site to the south. The pre-development drainage analyses are included in Attachment D-1.
2. Post-Development Conditions
For the Post-Development conditions, the site was delineated into four drainage areas and one
sub-area based on proposed grades and discharge locations (Figure 2). The proposed facility will
include a stormwater conveyance channel that collects runoff from the conveniences site and wet
pond maintenance road that discharges into a stormwater wet pond for treatment, detention of
peak flow, and controlled discharge via an outlet structure with orifices and weirs prior to discharge
over land to Avents Creek. The post-development drainage analyses are included in Attachment
D-2. The wet pond will be operated as a temporary sediment basin during construction with the
use of a skimmer. The skimmer will be removed once the site is stabilized so that discharge is
controlled by the orifices. The proposed wet pond will reduce the peak 25-year 24-hour post-
development flows to (Reach D7)Avents Creek to 21.09 cfs which is less than 10% increase over
the 19.92 cfs pre-development flows in accordance with the Article X of the Harnett County Unified
Development Ordinance.
Drainage Area 1 includes western portions of the site that discharge off-site via sheet flow and
shallow concentrated flow into the wooded buffer upland of Avents Creek. The area also included

Harnett County Northwest Convenience Center I Stormwater Permit Application—October 2024
Wet Pond Design
the wet pond. A drainage swale will cut-off and redirect run-off from the undisturbed areas from
entering the proposed wet pond.
Drainage Area 2 included undisturbed wooded areas and the western portion or the convenience
site and wet pond maintenance road. Runoff from these areas area collected in a drainage swale
and directed to the wet pond sediment forebay and wet pond for treatment prior to discharge to
the wooded buffer upgradient of Avents Creek.
Drainage Area 3 includes the eastern portion of the convenience site and run-off from this area is
collected by the drainage swale that directs flow to the west, joining flow from Area 2 prior to
discharge into the sediment forebay and wet pond.
Drainage Areas 4 includes the southeastern portions of the existing agricultural field and the
proposed entrance drive. Run-off from these areas will be collected in a roadside swale and
discharged to existing ditch along Oakridge River Road that discharges via overland flow via the
wooded buffer before entering Avents Creek.
Drainage Area 5 includes the eastern portion of the existing agricultural field and its runoff flows
to the east where it is collected in the roadside ditch along Oakridge River Road. The ditch
discharges beneath the new site driveway in a proposed 30-inch culvert prior to discharge into
the wooded buffer southeast of the convenience site and eventually into Avents Creek.
C. Wet Pond Design
The proposed wet pond design calculations are included in Attachment E.1. Details of the
proposed pond grades and outlet structure are included in the proposed construction drawings,
attached by reference to this application.
The wet pond is designed to treat a drainage area of 8.123 acres with 1.379 acres of impervious
area and has a design volume of 5,980 CF and main pond volume of 14,566 CF. The wet pond
includes a 6-foot wide vegetated shelf and an average depth of 4.62 feet. The wet pond
includes 6 inches of sediment storage for a volume of 738 CF. In addition, the sediment
forebay has a proposed volume of 2,214 CF which is within the range of 15% to 20% of the
main pond volume in accordance with NCDEQ Stormwater Design Manual Guidance C-3
(Attachment E.2).
The design volume discharge is regulated by three (3) 0.5-inch orifices at elevation of the
permanent pool of 322.14 MSL. The drawdown is calculated to be completed over a period of 4
days.
The wet pond discharge from a 1-year, 24-hour storm event is less than 0.29 cfs and thereby
minimizes any impact to the receiving channel upstream of Avents Creek.
An executed copy of the Operation and Maintenance Agreement is included in Attachment E.3.

Harnett County Northwest Convenience Center I Stormwater Permit Application—October 2024 r)�
Wet Pond Design
This page intentionally left blank.

Harnett County Northwest Convenience Center I Stormwater Permit Application—October 2024
Attachment A—USGS Plan
A
Attachment A — USGS
Plan

Harnett County Northwest Convenience Center I Stormwater Permit Application—October 2024 r)�
Attachment A—USGS Plan
This page intentionally left blank.

N
Harnett NW CC and Park W_<::::),E
S
Harnett 0 0.05 0.1 0.2 0.3
—1C-Th COUNTY GIS/E-911 Addressing — — Miles
NORTH CAROLINA June 5,2019 1 inch = 1,000 feet
AVENTS CREEK PROPOSED SITE
/ WS-IV;HQW
/1
W
E118 1427
Ici:tv°'3c°
J
o 8
U- (41
z P,k�
0
Sources:Esri,HERE,Garmin, Intermap,increment P Corp.,GEBCO,
USGS, FAO, NPS, NRCAN,GeoBase, IGN, Kadaster NL,Ordnance
Survey,Esri Japan, METI,Esri China(Hong Kong),(c)OpenStreetMap
contributors,and the GIS User Community
LEGEND
Recycle Center City Limits NC Parcels
Landfills _ Airport US CapeFearRiver
- - Surrounding County Boundaries MajorRoads Roads
Interstate Railroad
Federal Property

Harnett County Northwest Convenience Center I Stormwater Permit Application—October 2024 r)�
Attachment A—USGS Plan
This page intentionally left blank.

Harnett County Northwest Convenience Center I Stormwater Permit Application—October 2024 r)�
Attachment B—Soil Survey Report
B
Attachment B — Soil
Survey Report

Harnett County Northwest Convenience Center I Stormwater Permit Application—October 2024 r)�
Attachment B—Soil Survey Report
This page intentionally left blank.

USDA United States A product of the National Custom Soil Resource
Department of Cooperative Soil Survey,
Agriculture a joint effort of the United Report for
NStates Department of
RCS Agriculture and other Harnett County,
Federal agencies, State
Naturalagencies including the North Carolina
Resources Agricultural Experiment
Conservation Stations, and local
Service participants
Ng
illi
- �`�
--
4—
r Re
sOa 1 i
4( .lam }tit
•
\\I\ , . _s
i1
-
io f ,
d.
G L
z
ti. `'
) ._ ,- .
i0�
`'. `NM' a i, ."w^ A• it ,
_ - _r- _•
A_
te,s.
74 " tty',
0 •••••E•••• 1.000 ft r
1 / 1
May 30, 2019

Preface
Soil surveys contain information that affects land use planning in survey areas.
They highlight soil limitations that affect various land uses and provide information
about the properties of the soils in the survey areas. Soil surveys are designed for
many different users, including farmers, ranchers, foresters, agronomists, urban
planners, community officials, engineers, developers, builders, and home buyers.
Also, conservationists, teachers, students, and specialists in recreation, waste
disposal, and pollution control can use the surveys to help them understand,
protect, or enhance the environment.
Various land use regulations of Federal, State, and local governments may impose
special restrictions on land use or land treatment. Soil surveys identify soil
properties that are used in making various land use or land treatment decisions.
The information is intended to help the land users identify and reduce the effects of
soil limitations on various land uses. The landowner or user is responsible for
identifying and complying with existing laws and regulations.
Although soil survey information can be used for general farm, local, and wider area
planning, onsite investigation is needed to supplement this information in some
cases. Examples include soil quality assessments (http://www.nrcs.usda.gov/wps/
portal/nres/main/soils/health/) and certain conservation and engineering
applications. For more detailed information, contact your local USDA Service Center
(https://offices.sc.egov.usda.gov/locator/app?agency=nres)or your NRCS State Soil
Scientist(http://www.nres.usda.gov/wps/portal/nres/detail/soils/contactus/?
cid=nres142p2_053951).
Great differences in soil properties can occur within short distances. Some soils are
seasonally wet or subject to flooding. Some are too unstable to be used as a
foundation for buildings or roads. Clayey or wet soils are poorly suited to use as
septic tank absorption fields. A high water table makes a soil poorly suited to
basements or underground installations.
The National Cooperative Soil Survey is a joint effort of the United States
Department of Agriculture and other Federal agencies, State agencies including the
Agricultural Experiment Stations, and local agencies. The Natural Resources
Conservation Service (NRCS) has leadership for the Federal part of the National
Cooperative Soil Survey.
Information about soils is updated periodically. Updated information is available
through the NRCS Web Soil Survey, the site for official soil survey information.
The U.S. Department of Agriculture (USDA) prohibits discrimination in all its
programs and activities on the basis of race, color, national origin, age, disability,
and where applicable, sex, marital status, familial status, parental status, religion,
sexual orientation, genetic information, political beliefs, reprisal, or because all or a
part of an individual's income is derived from any public assistance program. (Not
all prohibited bases apply to all programs.) Persons with disabilities who require
2

alternative means for communication of program information (Braille, large print,
audiotape, etc.)should contact USDA's TARGET Center at [phone] (voice
and TDD). To file a complaint of discrimination, write to USDA, Director, Office of
Civil Rights, 1400 Independence Avenue, S.W., Washington, D.C. 20250-9410 or
call [phone] (voice)or(202) 720-6382 (TDD). USDA is an equal opportunity
provider and employer.
3

Contents
Preface 2
How Soil Surveys Are Made 5
Soil Map 8
Soil Map (Harnett County NW Convenience Center) 9
Legend 10
Map Unit Legend (Harnett County NW Convenience Center) 11
Map Unit Descriptions (Harnett County NW Convenience Center) 11
Harnett County, North Carolina 13
Bb—Bibb soils, frequently flooded 13
CeB—Cecil fine sandy loam, 2 to 8 percent slopes 14
CeD—Cecil fine sandy loam, 8 to 15 percent slopes 15
DoB—Dothan loamy sand, 2 to 6 percent slopes 16
FaB—Fuquay loamy sand, 0 to 6 percent slopes 17
PaE—Pacolet fine sandy loam, 15 to 25 percent slopes 19
W—Water 20
Wh—Wehadkee loam, frequently flooded 21
References 23
4

How Soil Surveys Are Made
Soil surveys are made to provide information about the soils and miscellaneous
areas in a specific area. They include a description of the soils and miscellaneous
areas and their location on the landscape and tables that show soil properties and
limitations affecting various uses. Soil scientists observed the steepness, length,
and shape of the slopes; the general pattern of drainage; the kinds of crops and
native plants; and the kinds of bedrock. They observed and described many soil
profiles. A soil profile is the sequence of natural layers, or horizons, in a soil. The
profile extends from the surface down into the unconsolidated material in which the
soil formed or from the surface down to bedrock. The unconsolidated material is
devoid of roots and other living organisms and has not been changed by other
biological activity.
Currently, soils are mapped according to the boundaries of major land resource
areas (MLRAs). MLRAs are geographically associated land resource units that
share common characteristics related to physiography, geology, climate, water
resources, soils, biological resources, and land uses (USDA, 2006). Soil survey
areas typically consist of parts of one or more MLRA.
The soils and miscellaneous areas in a survey area occur in an orderly pattern that
is related to the geology, landforms, relief, climate, and natural vegetation of the
area. Each kind of soil and miscellaneous area is associated with a particular kind
of landform or with a segment of the landform. By observing the soils and
miscellaneous areas in the survey area and relating their position to specific
segments of the landform, a soil scientist develops a concept, or model, of how they
were formed. Thus, during mapping, this model enables the soil scientist to predict
with a considerable degree of accuracy the kind of soil or miscellaneous area at a
specific location on the landscape.
Commonly, individual soils on the landscape merge into one another as their
characteristics gradually change. To construct an accurate soil map, however, soil
scientists must determine the boundaries between the soils. They can observe only
a limited number of soil profiles. Nevertheless, these observations, supplemented
by an understanding of the soil-vegetation-landscape relationship, are sufficient to
verify predictions of the kinds of soil in an area and to determine the boundaries.
Soil scientists recorded the characteristics of the soil profiles that they studied. They
noted soil color, texture, size and shape of soil aggregates, kind and amount of rock
fragments, distribution of plant roots, reaction, and other features that enable them
to identify soils. After describing the soils in the survey area and determining their
properties, the soil scientists assigned the soils to taxonomic classes (units).
Taxonomic classes are concepts. Each taxonomic class has a set of soil
characteristics with precisely defined limits. The classes are used as a basis for
comparison to classify soils systematically. Soil taxonomy, the system of taxonomic
classification used in the United States, is based mainly on the kind and character
of soil properties and the arrangement of horizons within the profile. After the soil
5

Custom Soil Resource Report
scientists classified and named the soils in the survey area, they compared the
individual soils with similar soils in the same taxonomic class in other areas so that
they could confirm data and assemble additional data based on experience and
research.
The objective of soil mapping is not to delineate pure map unit components; the
objective is to separate the landscape into landforms or landform segments that
have similar use and management requirements. Each map unit is defined by a
unique combination of soil components and/or miscellaneous areas in predictable
proportions. Some components may be highly contrasting to the other components
of the map unit. The presence of minor components in a map unit in no way
diminishes the usefulness or accuracy of the data. The delineation of such
landforms and landform segments on the map provides sufficient information for the
development of resource plans. If intensive use of small areas is planned, onsite
investigation is needed to define and locate the soils and miscellaneous areas.
Soil scientists make many field observations in the process of producing a soil map.
The frequency of observation is dependent upon several factors, including scale of
mapping, intensity of mapping, design of map units, complexity of the landscape,
and experience of the soil scientist. Observations are made to test and refine the
soil-landscape model and predictions and to verify the classification of the soils at
specific locations. Once the soil-landscape model is refined, a significantly smaller
number of measurements of individual soil properties are made and recorded.
These measurements may include field measurements, such as those for color,
depth to bedrock, and texture, and laboratory measurements, such as those for
content of sand, silt, clay, salt, and other components. Properties of each soil
typically vary from one point to another across the landscape.
Observations for map unit components are aggregated to develop ranges of
characteristics for the components. The aggregated values are presented. Direct
measurements do not exist for every property presented for every map unit
component. Values for some properties are estimated from combinations of other
properties.
While a soil survey is in progress, samples of some of the soils in the area generally
are collected for laboratory analyses and for engineering tests. Soil scientists
interpret the data from these analyses and tests as well as the field-observed
characteristics and the soil properties to determine the expected behavior of the
soils under different uses. Interpretations for all of the soils are field tested through
observation of the soils in different uses and under different levels of management.
Some interpretations are modified to fit local conditions, and some new
interpretations are developed to meet local needs. Data are assembled from other
sources, such as research information, production records, and field experience of
specialists. For example, data on crop yields under defined levels of management
are assembled from farm records and from field or plot experiments on the same
kinds of soil.
Predictions about soil behavior are based not only on soil properties but also on
such variables as climate and biological activity. Soil conditions are predictable over
long periods of time, but they are not predictable from year to year. For example,
soil scientists can predict with a fairly high degree of accuracy that a given soil will
have a high water table within certain depths in most years, but they cannot predict
that a high water table will always be at a specific level in the soil on a specific date.
After soil scientists located and identified the significant natural bodies of soil in the
survey area, they drew the boundaries of these bodies on aerial photographs and
6

Custom Soil Resource Report
identified each as a specific map unit. Aerial photographs show trees, buildings,
fields, roads, and rivers, all of which help in locating boundaries accurately.
7

Soil Map
The soil map section includes the soil map for the defined area of interest, a list of
soil map units on the map and extent of each map unit, and cartographic symbols
displayed on the map. Also presented are various metadata about data used to
produce the map, and a description of each soil map unit.
8

Custom Soil Resource Report
N Soil Map (Harnett County NW Convenience Center) N
M ry
691300 691400 691500 691600 6917W 691800 691900 692000 6921W 692200 692300 692400 692500 692600 692700
35°31'28"N 35°31'28"N
2010, ` •
ill
CeD A ,., ,
I
1 / W DoB
FaB- � 'r 1-- --.
'I i
` CeB
CeD ` �1
II\
->, - d ^ cS
Wh t
CeB � � �
4.....
CeD lifii \ \.
PaEAl
.414*
'0 -,.. r #,. .
1 w
M
N.
f5000 555n5 515,5 e7-)5 ea0505 aP Goo,' ,aOQ°
35°30'ST'N -.1111
35°30'57'N
6913W 691400 691500 691600 6917W 691800 691900 692000 6921W 692200 692300 692400 692500 692600 692700
3 3
Po si
M Map Scale:1:6,680 if printed on A landscape(11"x 8.5")sheet. N
Meters
P N 0 50 100 200 300
Feet
0 300 600 1200 1800
Map projection:Web Mercator Corner coordinates:WGS84 Edge tics:UTM Zone 17N WGS84
9

Custom Soil Resource Report
MAP LEGEND MAP INFORMATION
Area of Interest(AOI) ig Spoil Area The soil surveys that comprise your AOI were mapped at
Area of Interest(AOI) 1:24,000.
Q Stony Spot
SoilsCO Very Stony Spot
Soil Map Unit Polygons Warning:Soil Map may not be valid at this scale.
Wet Spot
"0 Soil Map Unit Lines Enlargement of maps beyond the scale of mapping can cause
Other misunderstandingof the detail of mapping and accuracyof soil
• Soil Map Unit Points pp g
•� Special Line Features line placement.The maps do not show the small areas of
Special Point Features contrasting soils that could have been shown at a more detailed
Blowout Water Features scale.
Streams and Canals
Borrow Pit
Transportation Please rely on the bar scale on each map sheet for map
Clay Spot .1-1-t Rails measurements.
▪ Closed Depression
O,1/ Interstate Highways
Gravel Pit Source of Map: Natural Resources Conservation Service
■y US Routes Web Soil Survey URL:
.1. Gravelly Spot Major Roads Coordinate System: Web Mercator(EPSG:3857)
Q Landfill Local Roads Maps from the Web Soil Survey are based on the Web Mercator
A. Lava Flow Background projection,which preserves direction and shape but distorts
distance and area.A projection that preserves area,such as the
dlle Marsh or swamp Aerial Photography Albers equal-area conic projection,should be used if more
A+ Mine or Quarry accurate calculations of distance or area are required.
O Miscellaneous Water This product is generated from the USDA-NRCS certified data as
0 Perennial Water of the version date(s)listed below.
v Rock Outcrop Soil Survey Area: Harnett County,North Carolina
+ Saline Spot Survey Area Data: Version 15,Sep 10,2018
• Sandy Spot Soil map units are labeled(as space allows)for map scales
Severely Eroded Spot 1:50,000 or larger.
O Sinkhole Date(s)aerial images were photographed: Jun 15,2015—Dec 9,
3) Slide or Slip 2017
• Sodic Spot 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.
10

Custom Soil Resource Report
Map Unit Legend (Harnett County NW
Convenience Center)
Map Unit Symbol Map Unit Name Acres in AOI Percent of AOI
Bb Bibb soils,frequently flooded 1.1 0.6%
CeB Cecil fine sandy loam,2 to 8 72.5 38.6%
percent slopes
CeD Cecil fine sandy loam,8 to 15 73.8 39.3%
percent slopes
DoB Dothan loamy sand,2 to 6 0.6 0.3%
percent slopes
FaB Fuquay loamy sand,0 to 6 24.8 13.2%
percent slopes
PaE Pacolet fine sandy loam, 15 to 0.1 0.0%
25 percent slopes
W Water 5.7 3.0%
Wh Wehadkee loam,frequently 9.3 4.9%
flooded
Totals for Area of Interest 187.9 100.0%
Map Unit Descriptions (Harnett County NW
Convenience Center)
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
11

Custom Soil Resource Report
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
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.
12

Custom Soil Resource Report
Harnett County, North Carolina
Bb—Bibb soils, frequently flooded
Map Unit Setting
National map unit symbol: 3snw
Elevation: 80 to 330 feet
Mean annual precipitation: 38 to 55 inches
Mean annual air temperature: 59 to 70 degrees F
Frost-free period: 210 to 265 days
Farmland classification: Not prime farmland
Map Unit Composition
Bibb, undrained, and similar soils: 80 percent
Johnston, undrained, and similar soils: 10 percent
Estimates are based on observations, descriptions, and transects of the mapunit.
Description of Bibb, Undrained
Setting
Landform: Flood plains
Landform position (two-dimensional): Toeslope
Down-slope shape: Concave
Across-slope shape: Linear
Parent material: Sandy and loamy alluvium
Typical profile
A -0 to 6 inches: sandy loam
Cg1 - 6 to 60 inches: sandy loam
Cg2- 60 to 80 inches: loamy sand
Properties and qualities
Slope: 0 to 2 percent
Depth to restrictive feature: More than 80 inches
Natural drainage class: Poorly drained
Runoff class: Low
Capacity of the most limiting layer to transmit water(Ksat): High (1.98 to 5.95
in/hr)
Depth to water table: About 0 to 12 inches
Frequency of flooding: Frequent
Frequency of ponding: None
Available water storage in profile: Moderate (about 7.2 inches)
Interpretive groups
Land capability classification (irrigated): None specified
Land capability classification (nonirrigated): 5w
Hydrologic Soil Group: A/D
Hydric soil rating: Yes
Description of Johnston, Undrained
Setting
Landform: Flood plains
Down-slope shape: Concave
Across-slope shape: Linear
Parent material: Sandy and loamy alluvium
13

Custom Soil Resource Report
Typical profile
A -0 to 30 inches: mucky loam
Cg1 -30 to 34 inches: loamy fine sand
Cg2-34 to 80 inches: fine sandy loam
Properties and qualities
Slope: 0 to 2 percent
Depth to restrictive feature: More than 80 inches
Natural drainage class: Very poorly drained
Runoff class: Ponded
Capacity of the most limiting layer to transmit water(Ksat): High (1.98 to 5.95
in/hr)
Depth to water table: About 0 inches
Frequency of flooding: Frequent
Frequency of ponding: Frequent
Available water storage in profile: High (about 9.4 inches)
Interpretive groups
Land capability classification (irrigated): None specified
Land capability classification (nonirrigated): 7w
Hydrologic Soil Group: A/D
Hydric soil rating: Yes
CeB—Cecil fine sandy loam, 2 to 8 percent slopes
Map Unit Setting
National map unit symbol: 3sp1
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
Cecil and similar soils: 90 percent
Estimates are based on observations, descriptions, and transects of the mapunit.
Description of Cecil
Setting
Landform: I nterfluves
Landform position (two-dimensional): Summit
Landform position (three-dimensional): Interfluve
Down-slope shape: Convex
Across-slope shape: Convex
Parent material: Saprolite derived from granite and gneiss and/or schist
Typical profile
Ap- 0 to 7 inches: fine sandy loam
Bt- 7 to 40 inches: clay
14

Custom Soil Resource Report
BC-40 to 55 inches: clay loam
C- 55 to 80 inches: sandy loam
Properties and qualities
Slope: 2 to 8 percent
Depth to restrictive feature: More than 80 inches
Natural drainage class: Well drained
Runoff class: Medium
Capacity of the most limiting layer to transmit water(Ksat): Moderately high to
high (0.57 to 1.98 in/hr)
Depth to water table: More than 80 inches
Frequency of flooding: None
Frequency of ponding: None
Available water storage in profile: Moderate (about 8.2 inches)
Interpretive groups
Land capability classification (irrigated): None specified
Land capability classification (nonirrigated): 2e
Hydrologic Soil Group: A
Hydric soil rating: No
CeD—Cecil fine sandy loam, 8 to 15 percent slopes
Map Unit Setting
National map unit symbol: 3sp2
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
Cecil and similar soils: 85 percent
Estimates are based on observations, descriptions, and transects of the mapunit.
Description of Cecil
Setting
Landform: I nterfluves
Landform position (two-dimensional): Summit, shoulder
Landform position (three-dimensional): Interfluve
Down-slope shape: Convex
Across-slope shape: Convex
Parent material: Saprolite derived from granite and gneiss and/or schist
Typical profile
Ap- 0 to 7 inches: fine sandy loam
Bt- 7 to 40 inches: clay
BC-40 to 55 inches: clay loam
C- 55 to 80 inches: sandy loam
Properties and qualities
Slope: 8 to 15 percent
15

Custom Soil Resource Report
Depth to restrictive feature: More than 80 inches
Natural drainage class: Well drained
Runoff class: Medium
Capacity of the most limiting layer to transmit water(Ksat): Moderately high to
high (0.57 to 1.98 in/hr)
Depth to water table: More than 80 inches
Frequency of flooding: None
Frequency of ponding: None
Available water storage in profile: Moderate (about 8.2 inches)
Interpretive groups
Land capability classification (irrigated): None specified
Land capability classification (nonirrigated): 3e
Hydrologic Soil Group: A
Hydric soil rating: No
DoB—Dothan loamy sand, 2 to 6 percent slopes
Map Unit Setting
National map unit symbol: 2wb94
Elevation: 50 to 660 feet
Mean annual precipitation: 40 to 69 inches
Mean annual air temperature: 55 to 70 degrees F
Frost-free period: 190 to 310 days
Farmland classification: All areas are prime farmland
Map Unit Composition
Dothan and similar soils: 82 percent
Minor components: 18 percent
Estimates are based on observations, descriptions, and transects of the mapunit.
Description of Dothan
Setting
Landform: I nterfluves
Landform position (two-dimensional): Shoulder
Landform position (three-dimensional): Interfluve
Down-slope shape: Convex
Across-slope shape: Linear
Parent material: Loamy marine deposits
Typical profile
Ap- 0 to 7 inches: loamy sand
E- 7 to 13 inches: loamy sand
Bt- 13 to 40 inches: sandy clay loam
Btv-40 to 79 inches: sandy clay loam
Properties and qualities
Slope: 2 to 6 percent
Depth to restrictive feature: More than 80 inches
Natural drainage class: Well drained
16

Custom Soil Resource Report
Capacity of the most limiting layer to transmit water(Ksat): Moderately high (0.20
to 0.57 in/hr)
Depth to water table: About 36 to 59 inches
Frequency of flooding: None
Frequency of ponding: None
Salinity, maximum in profile: Nonsaline to very slightly saline (0.0 to 2.0
mmhos/cm)
Available water storage in profile: Moderate (about 6.8 inches)
Interpretive groups
Land capability classification (irrigated): None specified
Land capability classification (nonirrigated): 2e
Hydrologic Soil Group: B
Forage suitability group: Loamy and clayey soils on rises and knolls of mesic
uplands (G133AA321 FL)
Hydric soil rating: No
Minor Components
Norfolk
Percent of map unit: 8 percent
Landform: I nterfluves
Landform position (two-dimensional): Shoulder
Landform position (three-dimensional): Interfluve
Down-slope shape: Convex
Across-slope shape: Linear
Hydric soil rating: No
Fuquay
Percent of map unit: 5 percent
Landform: I nterfluves
Landform position (two-dimensional): Shoulder
Landform position (three-dimensional): Interfluve
Down-slope shape: Convex
Across-slope shape: Linear
Hydric soil rating: No
Orangeburg
Percent of map unit: 5 percent
Landform: Marine terraces
Landform position (two-dimensional): Backslope, shoulder, summit
Landform position (three-dimensional): Side slope
Down-slope shape: Linear
Across-slope shape: Convex, linear
Hydric soil rating: No
FaB—Fuquay loamy sand, 0 to 6 percent slopes
Map Unit Setting
National map unit symbol: 2wb9d
Elevation: 160 to 660 feet
17

Custom Soil Resource Report
Mean annual precipitation: 40 to 69 inches
Mean annual air temperature: 55 to 70 degrees F
Frost-free period: 190 to 310 days
Farmland classification: Farmland of statewide importance
Map Unit Composition
Fuquay and similar soils: 85 percent
Minor components: 15 percent
Estimates are based on observations, descriptions, and transects of the mapunit.
Description of Fuquay
Setting
Landform: I nterfluves
Landform position (two-dimensional): Shoulder
Landform position (three-dimensional): Interfluve
Down-slope shape: Convex
Across-slope shape: Linear
Parent material: Sandy marine deposits over loamy marine deposits
Typical profile
Ap- 0 to 10 inches: loamy sand
E- 10 to 28 inches: loamy sand
Bt- 28 to 44 inches: sandy clay loam
Btv-44 to 80 inches: sandy clay loam
Properties and qualities
Slope: 0 to 6 percent
Depth to restrictive feature: More than 80 inches
Natural drainage class: Well drained
Capacity of the most limiting layer to transmit water(Ksat): Moderately high (0.20
to 0.57 in/hr)
Depth to water table: About 40 to 61 inches
Frequency of flooding: None
Frequency of ponding: None
Salinity, maximum in profile: Nonsaline to very slightly saline (0.0 to 2.0
mmhos/cm)
Sodium adsorption ratio, maximum in profile: 4.0
Available water storage in profile: Low (about 5.8 inches)
Interpretive groups
Land capability classification (irrigated): None specified
Land capability classification (nonirrigated): 2s
Hydrologic Soil Group: B
Forage suitability group: Sandy over loamy soils on rises, knolls, and ridges of
mesic uplands (G133AA221FL)
Hydric soil rating: No
Minor Components
Dothan
Percent of map unit: 7 percent
Landform: I nterfluves
Landform position (two-dimensional): Shoulder
Landform position (three-dimensional): Interfluve
Down-slope shape: Convex
Across-slope shape: Linear
18

Custom Soil Resource Report
Hydric soil rating: No
Candor
Percent of map unit: 5 percent
Landform: Marine terraces
Landform position (two-dimensional): Footslope, summit, shoulder
Landform position (three-dimensional): Interfluve
Down-slope shape: Convex, linear
Across-slope shape: Convex, linear
Hydric soil rating: No
Blaney
Percent of map unit: 3 percent
Landform: Ridges
Landform position (two-dimensional): Backslope, shoulder, summit
Landform position (three-dimensional): Interfluve, side slope
Down-slope shape: Convex
Across-slope shape: Convex
Hydric soil rating: No
PaE—Pacolet fine sandy loam, 15 to 25 percent slopes
Map Unit Setting
National map unit symbol: 3sq5
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: Not prime farmland
Map Unit Composition
Pacolet and similar soils: 85 percent
Minor components: 13 percent
Estimates are based on observations, descriptions, and transects of the mapunit.
Description of Pacolet
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: Saprolite derived from granite and gneiss and/or schist
Typical profile
Ap- 0 to 5 inches: sandy loam
E-5 to 8 inches: sandy loam
Bt- 8 to 29 inches: clay
BC-29 to 38 inches: sandy clay loam
C-38 to 80 inches: sandy loam
19

Custom Soil Resource Report
Properties and qualities
Slope: 15 to 25 percent
Depth to restrictive feature: More than 80 inches
Natural drainage class: Well drained
Runoff class: High
Capacity of the most limiting layer to transmit water(Ksat): Moderately high to
high (0.57 to 1.98 in/hr)
Depth to water table: More than 80 inches
Frequency of flooding: None
Frequency of ponding: None
Available water storage in profile: Moderate (about 7.4 inches)
Interpretive groups
Land capability classification (irrigated): None specified
Land capability classification (nonirrigated): 4e
Hydrologic Soil Group: B
Hydric soil rating: No
Minor Components
Spartanburg
Percent of map unit: 8 percent
Landform: Hillslopes on ridges
Landform position (two-dimensional): Backslope
Landform position (three-dimensional): Side slope
Down-slope shape: Linear
Across-slope shape: Convex
Hydric soil rating: No
Bethlehem
Percent of map unit: 5 percent
Landform: Hillslopes on ridges
Landform position (two-dimensional): Backslope
Landform position (three-dimensional): Side slope
Down-slope shape: Linear
Across-slope shape: Convex
Hydric soil rating: No
W—Water
Map Unit Composition
Water: 100 percent
Estimates are based on observations, descriptions, and transects of the mapunit.
Description of Water
Interpretive groups
Land capability classification (irrigated): None specified
Land capability classification (nonirrigated): 8w
Hydric soil rating: No
20

Custom Soil Resource Report
Wh—Wehadkee loam, frequently flooded
Map Unit Setting
National map unit symbol: 3sqv
Elevation: 80 to 330 feet
Mean annual precipitation: 38 to 55 inches
Mean annual air temperature: 59 to 70 degrees F
Frost-free period: 210 to 265 days
Farmland classification: Not prime farmland
Map Unit Composition
Wehadkee, undrained, and similar soils: 80 percent
Wehadkee, drained, and similar soils: 10 percent
Estimates are based on observations, descriptions, and transects of the mapunit.
Description of Wehadkee, Undrained
Setting
Landform: Depressions on flood plains
Down-slope shape: Concave
Across-slope shape: Linear
Parent material: Loamy alluvium
Typical profile
A -0to7inches: loam
Bg- 7 to 58 inches: loam
Cg- 58 to 84 inches: sandy loam
Properties and qualities
Slope: 0 to 2 percent
Depth to restrictive feature: More than 80 inches
Natural drainage class: Poorly drained
Runoff class: Very high
Capacity of the most limiting layer to transmit water(Ksat): Moderately high to
high (0.57 to 1.98 in/hr)
Depth to water table: About 0 to 12 inches
Frequency of flooding: Frequent
Frequency of ponding: None
Available water storage in profile: High (about 10.4 inches)
Interpretive groups
Land capability classification (irrigated): None specified
Land capability classification (nonirrigated): 6w
Hydrologic Soil Group: B/D
Hydric soil rating: Yes
Description of Wehadkee, Drained
Setting
Landform: Depressions on flood plains
Down-slope shape: Concave
Across-slope shape: Linear
Parent material: Loamy alluvium
21

Custom Soil Resource Report
Typical profile
A -O to 7 inches: loam
Bg- 7 to 58 inches: loam
Cg- 58 to 84 inches: sandy loam
Properties and qualities
Slope: 0 to 2 percent
Depth to restrictive feature: More than 80 inches
Natural drainage class: Poorly drained
Runoff class: Very high
Capacity of the most limiting layer to transmit water(Ksat): Moderately high to
high (0.57 to 1.98 in/hr)
Depth to water table: About 0 to 12 inches
Frequency of flooding: Frequent
Frequency of ponding: None
Available water storage in profile: High (about 10.4 inches)
Interpretive groups
Land capability classification (irrigated): None specified
Land capability classification (nonirrigated): 4w
Hydrologic Soil Group: B/D
Hydric soil rating: Yes
22

References
American Association of State Highway and Transportation Officials (AASHTO).
2004. Standard specifications for transportation materials and methods of sampling
and testing. 24th edition.
American Society for Testing and Materials (ASTM). 2005. Standard classification of
soils for engineering purposes. ASTM Standard D2487-00.
Cowardin, L.M., V. Carter, F.C. Golet, and E.T. LaRoe. 1979. Classification of
wetlands and deep-water habitats of the United States. U.S. Fish and Wildlife
Service FWS/OBS-79/31.
Federal Register. July 13, 1994. Changes in hydric soils of the United States.
Federal Register. September 18, 2002. Hydric soils of the United States.
Hurt, G.W., and L.M. Vasilas, editors. Version 6.0, 2006. Field indicators of hydric
soils in the United States.
National Research Council. 1995. Wetlands: Characteristics and boundaries.
Soil Survey Division Staff. 1993. Soil survey manual. Soil Conservation Service.
U.S. Department of Agriculture Handbook 18. http://www.nres.usda.gov/wps/portal/
nres/detai l/national/soi ls/?cid=nres 142p2_054262
Soil Survey Staff. 1999. Soil taxonomy: A basic system of soil classification for
making and interpreting soil surveys. 2nd edition. Natural Resources Conservation
Service, U.S. Department of Agriculture Handbook 436. http://
www.nres.usda.gov/wps/portal/nres/detail/national/soils/?cid=nres 142p2_053577
Soil Survey Staff. 2010. Keys to soil taxonomy. 11th edition. U.S. Department of
Agriculture, Natural Resources Conservation Service. http://
www.nres.usda.gov/wps/portal/nres/detail/national/soils/?cid=nres 142p2_053580
Tiner, R.W., Jr. 1985. Wetlands of Delaware. U.S. Fish and Wildlife Service and
Delaware Department of Natural Resources and Environmental Control, Wetlands
Section.
United States Army Corps of Engineers, Environmental Laboratory. 1987. Corps of
Engineers wetlands delineation manual. Waterways Experiment Station Technical
Report Y-87-1.
United States Department of Agriculture, Natural Resources Conservation Service.
National forestry manual. http://www.nrcs.usda.gov/wps/portal/nrcs/detail/soils/
home/?cid=nres142p2_053374
United States Department of Agriculture, Natural Resources Conservation Service.
National range and pasture handbook. http://www.nres.usda.gov/wps/portal/nres/
detail/national/landuse/rangepasture/?cid=stelprdb1043084
23

Custom Soil Resource Report
United States Department of Agriculture, Natural Resources Conservation Service.
National soil survey handbook, title 430-VI. http://www.nres.usda.gov/wps/portal/
nres/detail/soils/scientists/?cid=nres142p2_054242
United States Department of Agriculture, Natural Resources Conservation Service.
2006. Land resource regions and major land resource areas of the United States,
the Caribbean, and the Pacific Basin. U.S. Department of Agriculture Handbook
296. http://www.nres.usda.gov/wps/portal/nres/detail/national/soils/?
cid=nres142p2_053624
United States Department of Agriculture, Soil Conservation Service. 1961. Land
capability classification. U.S. Department of Agriculture Handbook 210. http://
www.nrcs.usda.gov/Internet/FSE_DOCUMENTS/nrcs142p2_052290.pdf
24

Harnett County Northwest Convenience Center I Stormwater Permit Application—October 2024 r)�
Attachment C—Precipitation
Frequency Data
C
Attachment C —
Precipitation Frequency
Data

Harnett County Northwest Convenience Center I Stormwater Permit Application—October 2024 r)�
Attachment C—Precipitation
Frequency Data
This page intentionally left blank.

Point precipitation frequency estimates(inches)
NOAA Atlas 14 Volume 2 Version 3
Data type: Precipitation depth
Time series type: Partial duration
Project area: Ohio River Basin
Location n< North Carr USA
Station Name: DUNN 4 NW
Latitude: 35.3247°
Longitude:-78.6881°
Elevation (USGS):200 ft
PRECIPITATION FREQUENCY ESTIMATES
by duratior 1 2 5 10 25 50 100 200 500 1000
5-min: 0.437 0.513 0.594 0.659 0.734 0.791 0.844 0.894 0.954 1.01
10-min: 0.697 0.821 0.951 1.06 1.17 1.26 1.34 1.42 1.51 1.58
15-min: 0.872 1.03 1.2 1.33 1.48 1.59 1.7 1.79 1.9 1.99
30-min: 1.2 1.43 1.71 1.93 2.2 2.4 2.6 2.78 3.02 3.22
60-min: 1.49 1.79 2.19 2.52 2.93 3.25 3.58 3.9 4.34 4.69
2-hr: 1.75 2.12 2.63 3.06 3.63 4.09 4.56 5.06 5.72 6.29
3-hr: 1.86 2.25 2.81 3.29 3.94 4.49 5.07 5.68 6.53 7.28
6-hr: 2.22 2.68 3.35 3.94 4.73 5.41 6.13 6.89 7.97 8.91
12-hr: 2.61 3.15 3.96 4.68 5.67 6.52 7.42 8.41 9.82 11.1
24-hr: 3.05 3.7 4.74 5.58 6.75 7.72 8.73 9.8 11.3 12.5
2-day: 3.57 4.32 5.49 6.42 7.73 8.81 9.93 11.1 12.8 14.2
3-day: 3.8 4.59 5.79 6.76 8.1 9.19 10.3 11.5 13.2 14.6
4-day: 4.03 4.86 6.1 7.09 8.47 9.58 10.7 12 13.7 15.1
7-day: 4.67 5.6 6.95 8.02 9.49 10.7 11.9 13.2 15 16.4
10-day: 5.33 6.38 7.78 8.87 10.4 11.5 12.7 14 15.6 17
20-day: 7.18 8.53 10.2 11.6 13.4 14.8 16.2 17.7 19.7 21.3
30-day: 8.95 10.6 12.5 13.9 15.9 17.3 18.8 20.3 22.3 23.8
45-day: 11.4 13.4 15.5 17.2 19.3 20.9 22.5 24.1 26.2 27.8
60-day: 13.6 16 18.4 20.2 22.5 24.3 26 27.7 29.9 31.6
Date/time(GMT): Thu May 30 12:52:27 2019
pyRunTime: 0.0106019973755

Harnett County Northwest Convenience Center I Stormwater Permit Application—October 2024 r)�
Attachment C—Precipitation
Frequency Data
This page intentionally left blank.

Harnett County Northwest Convenience Center I Stormwater Permit Application—October 2024 r)�
Attachment D—Stormwater Flow
D
Aachment D —
Stormwatett r Flow

Harnett County Northwest Convenience Center I Stormwater Permit Application—October 2024 r)�
Attachment D—Stormwater Flow
This page intentionally left blank.

Harnett County Solid Waste Department I Stormwater Permit Application—October 2024 r)�
Attachment D.1 —Pre-Development Calculations
D . 1
Attachment D. 1 — Pre-
Development Calculations

Harnett County Solid Waste Department I Stormwater Permit Application—October 2024 r)�
Attachment D.1 —Pre-Development Calculations
This page intentionally left blank.

1 2 3 4 5 6 7 8
_ 1141�I'I'lllllllllllllli�lili
���y N
__.__
=:::--...........-./...'
(7N\
/ '
D
m
LEGEND:
yyy boy oyo EXISTING CONTOURS
LOC LIMITS OF CONSTRUCTION
�y° rR,,rmr<I, c' 35p BUFFER ZONE
APPROXIMATE EDGE OF TREE LINE
3SS Amelet
/ E911 TOWER RADIUS
y "SS TOWER TOWER FENCE
P37337777 ADJACENT PUBLIC ROW
33 DSO _ w w w
350- '-'1 \ AREAL 11.fi09 AC 6"WATER MAIN
401
.._ ,
50'BUFFE' 3 TIME TO CONCENTRATION
100 LF SHEET FLOW
11111� . Sp 1068 LF SHALLOW CONC
r
ilL ),
/// /' ' II��/ OP PROP7LIN 4I 4* �6 C
'+j �'S i
TIMETOCAREA 4:ONCENT ,,,,
T FLOW RATIONi \\; II�ii
4n,0�68' O3s I S061LFSHALLOW COC '� '295 _u 3pBUFE �! % I 290 �200��S jIAREA 2:5.131 ACRATION \ ' ,per
280 285 M O� P PROPERTY Ll�ry /// 1, TIME 1// ,, 00 LOF SHEETLOW IMITS OF CONS RUCTION o I _moo a
600 LF SHALLOW CONC
Alk
lk
Mr
,y9° 320 -N315 011
- - �• � 36pSI' I ING6-INCHN 4F( /
310 - ' 11'i� - -- WATERMAN ar
I , !
305N SS� / i I\\ AREA?t231 AC ` Y
� TIME TO CONCENTRATION' � N--- O
\\.. 300 0%4 I') N O m y 100 LF SHEET FLOW ..,..,.. _\ I h� B
\a\l.tekg
N g0 226 LF SHALLOW CONC
N)N\\ o- 96' 2 ? /'S `\ APPROXIMATE LOCATION? �"�
N 2 85 MI OF THREE EXISTING TREES
)) \\0\1:s B' 26Q (/' ,yet°/ 345APPROXIMATERO`/T OF_, LIjw. � EXISTING TREE LINEr
N N j0 275 3"'Sp `74p 3q5 ��� (----346\\
wwV`
NIN 2- 5 m Yp
� N 265 � �
'((
320 35
0 b �iti N �5/ �S
�o/ 4' 310 3y0 a�p ,, o
N ��`rd305 Na. Qy _ SSA dNSo 315 _ N 32S
,n N a 4 aS0 O to
,,,,,,, a S 300 310 !� ,n ��
o
N tt �:6S� 295 305 M' #� �ry0
AVENTS CREEK gyp gp n , A
o _.� 11 NTIRE SITE DRAINS THROUGH NATURAL 290 9s p `h� t
CHANNELS IN DRAWS AND INTO ADVENT CREEK N
\p 285 N /___
NOTES:
�, 25‘/))),\))
i� 255605280 i /re 1. EXISTING TOPOGRAPHY AND PROPERTY LINES OBTAINED FROM
2Sp275 ' / HARNETT COUNTY GIS.
250 ya 270 /`ti° 330 2. PROPERTY BOUNDARY SURVEY COMPLETED BY BENTON W.
g5 .� t // DEWARE AND ASSOCIATES,APRIL 30,2019.
N ryyy ryN°,yby,�y0 25y Z6 25`— ` ,210��,1-g0 2854. 32S i 3. CONDITIONAL USE PERMIT#BA-CU-18-18 APPROVED 6/11/18.
0 Harnett
PROJECT MANAGER J.MURRAY,PE H a Y n ett
'q HDREngineering,Inc.oftheCarolinas PROJECT ENGINEER A.MCGREW,PE -m 0 U N T Y HYDROCAD MODEL
EXISTING CONDITIONS
DRAWN BY A.MCGREW,PE ` -
§
N.C.B.E.L.S.License Number:F-0116 NORTH CAROLINA KEY
strong roots new growth
Q Rae gheNte2760treet,Suite900 C 05/2024 ISSUED FOR BIDDING HARNETT COUNTY
II F)/ 919.232.6600 B 01/2023 REVISED BASED ON REVIEWER COMMENTS NORTHWEST CONVENIENCE CENTER 0 1" 2" FILENAME OOG-02 dwg SHEET
A 10/2022 ISSUED FOR PERMITTING OOG-01
ISSUE DATE DESCRIPTION PROJECT NUMBER 10354679 HARNETT COUNTY NORTH CAROLINA SCALE 1"=75'

4 D DO
Area 4 NCDOT Load Ditch
0
C B1
Existing ulvert
Area 1
0
2 D4
D1
Area 2 Arla 3 Di Next to Road
D w
D2 D3
D5 Draw Dr w
Draw
D6
D7 Draw
\\\\\MICA• ii//0
Outfall to Avent Creek \\n��F S ".e,/GINi
c9? 1I
4,.... ...•.0. •
, 4, 010 M\\\\\\
4ubca) Reach 'On• MI Routing Diagram for 20221019_Harnett County_NW CC_Existing Conditions
Prepared by HDR, Inc, Printed 10/19/2022
HydroCAD®10.00-25 s/n 11397 ©2019 HydroCAD Software Solutions LLC

20221019_Harnett County_NW CC_Existing Conditions
Prepared by HDR, Inc Printed 10/19/2022
HydroCAD® 10.00-25 s/n 11397 ©2019 HydroCAD Software Solutions LLC Page 2
Area Listing (all nodes)
Area CN Description
(acres) (subcatchment-numbers)
15.192 61 >75% Grass cover, Good, HSG B (1, 2, 4)
11.258 55 Woods, Good, HSG B (1, 2, 3)
26.450 58 TOTAL AREA

20221019_Harnett County_NW CC_Existing Conditions
Prepared by HDR, Inc Printed 10/19/2022
HydroCAD® 10.00-25 s/n 11397 ©2019 HydroCAD Software Solutions LLC Page 3
Soil Listing (all nodes)
Area Soil Subcatchment
(acres) Group Numbers
0.000 HSG A
26.450 HSG B 1, 2, 3, 4
0.000 HSG C
0.000 HSG D
0.000 Other
26.450 TOTAL AREA

20221019_Harnett County_NW CC_Existing Conditions
Prepared by HDR, Inc Printed 10/19/2022
HydroCAD® 10.00-25 s/n 11397 ©2019 HydroCAD Software Solutions LLC Page 4
Ground Covers (all nodes)
HSG-A HSG-B HSG-C HSG-D Other Total Ground Subcatchment
(acres) (acres) (acres) (acres) (acres) (acres) Cover Numbers
0.000 15.192 0.000 0.000 0.000 15.192 >75% Grass cover, Good 1, 2, 4
0.000 11.258 0.000 0.000 0.000 11.258 Woods, Good 1, 2, 3
0.000 26.450 0.000 0.000 0.000 26.450 TOTAL AREA

20221019_Harnett County_NW CC_Existing Conditions
Prepared by HDR, Inc Printed 10/19/2022
HydroCAD® 10.00-25 s/n 11397 ©2019 HydroCAD Software Solutions LLC Page 5
Pipe Listing (all nodes)
Line# Node In-Invert Out-Invert Length Slope n Diam/Width Height Inside-Fill
Number (feet) (feet) (feet) (ft/ft) (inches) (inches) (inches)
1 C 1 354.50 351.00 137.0 0.0255 0.012 12.0 0.0 0.0

20221019_Harnett County_NW CC_Existing Conditions Type 1124-hr 1y24h Rainfall=3.05"
Prepared by HDR, Inc Printed 10/19/2022
HydroCAD® 10.00-25 s/n 11397 ©2019 HydroCAD Software Solutions LLC Page 6
Time span=5.00-20.00 hrs, dt=0.05 hrs, 301 points
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN
Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method
Subcatchment 1: Area 1 Runoff Area=11.609 ac 0.00% Impervious Runoff Depth>0.24"
Flow Length=1,164' Tc=28.9 min CN=58 Runoff=1.39 cfs 0.230 af
Subcatchment 2: Area 2 Runoff Area=5.131 ac 0.00% Impervious Runoff Depth>0.21"
Flow Length=700' Tc=22.2 min CN=57 Runoff=0.59 cfs 0.091 af
Subcatchment 3: Area 3 Runoff Area=1.231 ac 0.00% Impervious Runoff Depth>0.17"
Flow Length=326' Tc=22.4 min CN=55 Runoff=0.08 cfs 0.017 af
Subcatchment 4: Area 4 Runoff Area=8.479 ac 0.00% Impervious Runoff Depth>0.33"
Flow Length=606' Tc=13.1 min CN=61 Runoff=2.92 cfs 0.231 af
Reach DO: NCDOT Road Ditch Avg. Flow Depth=0.42' Max Vel=2.10 fps Inflow=2.92 cfs 0.231 af
n=0.035 L=1,130.0' S=0.0146 '/' Capacity=201.86 cfs Outflow=2.01 cfs 0.226 af
Reach D1: Draw Avg. Flow Depth=0.12' Max Vel=0.22 fps Inflow=1.39 cfs 0.230 af
n=0.400 L=500.0' S=0.0620 '/' Capacity=252.99 cfs Outflow=0.76 cfs 0.206 af
Reach D2: Draw Avg. Flow Depth=0.10' Max Vel=0.24 fps Inflow=0.59 cfs 0.091 af
n=0.400 L=430.0' S=0.0977 '/' Capacity=211.86 cfs Outflow=0.33 cfs 0.084 af
Reach D3: Draw Avg. Flow Depth=0.02' Max Vel=0.14 fps Inflow=0.08 cfs 0.017 af
n=0.400 L=228.0' S=0.1667 '/' Capacity=432.67 cfs Outflow=0.05 cfs 0.016 af
Reach D4: Ditch Next to Road Avg. Flow Depth=0.54' Max Vel=0.53 fps Inflow=2.01 cfs 0.226 af
n=0.400 L=500.0' S=0.0720 '/' Capacity=49.87 cfs Outflow=1.31 cfs 0.216 af
Reach D5: Draw Avg. Flow Depth=0.22' Max Vel=0.29 fps Inflow=1.05 cfs 0.290 af
n=0.400 L=982.0' S=0.0570 '/' Capacity=120.90 cfs Outflow=0.73 cfs 0.237 af
Reach D6: Draw Avg. Flow Depth=0.10' Max Vel=0.18 fps Inflow=1.35 cfs 0.232 af
n=0.400 L=1,720.0' S=0.0500 '/' Capacity=198.54 cfs Outflow=0.38 cfs 0.119 af
Reach D7: Outfall to Avent Creek Avg. Flow Depth=0.20' Max Vel=0.24 fps Inflow=0.90 cfs 0.356 af
n=0.400 L=130.0' S=0.0385 '/' Capacity=132.42 cfs Outflow=0.90 cfs 0.339 af
Pond C 1: Existing Culvert Peak Elev=355.29' Inflow=2.01 cfs 0.226 af
Primary=2.01 cfs 0.226 af Secondary=0.00 cfs 0.000 af Outflow=2.01 cfs 0.226 af
Total Runoff Area = 26.450 ac Runoff Volume = 0.570 af Average Runoff Depth = 0.26"
100.00% Pervious = 26.450 ac 0.00% Impervious = 0.000 ac

20221019_Harnett County_NW CC_Existing Conditions Type II 24-hr ly 24h Rainfall=3.05"
Prepared by HDR, Inc Printed 10/19/2022
HydroCAD® 10.00-25 s/n 11397 ©2019 HydroCAD Software Solutions LLC Page 7
Summary for Subcatchment 1: Area 1
Runoff = 1.39 cfs @ 12.35 hrs, Volume= 0.230 af, Depth> 0.24"
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs
Type II 24-hr 1y 24h Rainfall=3.05"
Area (ac) CN Description
5.230 61 >75% Grass cover, Good, HSG B
6.379 55 Woods, Good, HSG B
11.609 58 Weighted Average
11.609 100.00% Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
13.3 100 0.0200 0.13 Sheet Flow,
Grass: Dense n= 0.240 P2= 3.70"
15.6 1,064 0.0520 1.14 Shallow Concentrated Flow,
Woodland Kv= 5.0 fps
28.9 1,164 Total
Subcatchment 1: Area 1
Hydrograph
D Runoff
1 1.39 cfs I
j Type 1124-h r
_ 0 ly 24h Rainfall=3.05"
Runoff Area=11.609 ac
'" lillir Runoff Volume=0.230 af
0 Runoff Depth>0.24"
LL �j Flow Length=1,164'
/% Tc=28.9 min
�� CN=58
i x
5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
Time (hours)

20221019_Harnett County_NW CC_Existing Conditions Type II 24-hr ly 24h Rainfall=3.05"
Prepared by HDR, Inc Printed 10/19/2022
HydroCAD® 10.00-25 s/n 11397 ©2019 HydroCAD Software Solutions LLC Page 8
Summary for Subcatchment 2: Area 2
Runoff = 0.59 cfs @ 12.26 hrs, Volume= 0.091 af, Depth> 0.21"
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs
Type II 24-hr 1y 24h Rainfall=3.05"
Area (ac) CN Description
1.483 61 >75% Grass cover, Good, HSG B
3.648 55 Woods, Good, HSG B
5.131 57 Weighted Average
5.131 100.00% Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
9.1 100 0.0200 0.18 Sheet Flow,
Grass: Short n= 0.150 P2= 3.70"
13.1 600 0.0233 0.76 Shallow Concentrated Flow,
Woodland Kv= 5.0 fps
22.2 700 Total
Subcatchment 2: Area 2
Hydrograph
0.65- 1 1 Runoff
l 0.59 cfs l
0°5- : '
244h r
..._....24h Rain'faIi 3.05"___.
11
0.45
Runoff Area=5. 131..ac...
Runoff''':Volume=0.091 of
0.35 Runoff Depth>0.21"
LL 0.3 Flow Length=700'
�
/�_.... ..... To22.2_.min__.
0.2
1111 N--
7......
0.05-
0-/ A
5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
Time (hours)

20221019_Harnett County_NW CC_Existing Conditions Type II 24-hr ly 24h Rainfall=3.05"
Prepared by HDR, Inc Printed 10/19/2022
HydroCAD® 10.00-25 s/n 11397 ©2019 HydroCAD Software Solutions LLC Page 9
Summary for Subcatchment 3: Area 3
Runoff = 0.08 cfs @ 12.29 hrs, Volume= 0.017 af, Depth> 0.17"
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs
Type II 24-hr 1y 24h Rainfall=3.05"
Area (ac) CN Description
1.231 55 Woods, Good, HSG B
1.231 100.00% Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
20.0 100 0.0200 0.08 Sheet Flow,
Woods: Light underbrush n= 0.400 P2= 3.70"
2.4 226 0.0973 1.56 Shallow Concentrated Flow,
Woodland Kv= 5.0 fps
22.4 326 Total
Subcatchment 3: Area 3
Hydrograph
0.09_ ........ ■Runoff
0.085= .os
I
0 fs
0.08 i
;.. r
Type
0.075
ly 24h RainfaN=3.05" _.
0.07
0.065 i / Runoff Area=1 .231 ac.........
Runoff folume—O q.1. ..af..
0.055
Runoff_ Depth>0.17"
0.05=
•
3 0.045 ......................:........................................._......................... 2��
LL 0.04_ Flow Length=3
0.035
i -�- ;_Tc 224
0.03
0.025 I I __ ' CN=6S........
0.015
0.005
6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
Time (hours)

20221019_Harnett County_NW CC_Existing Conditions Type II 24-hr ly 24h Rainfall=3.05"
Prepared by HDR, Inc Printed 10/19/2022
HydroCAD® 10.00-25 s/n 11397 ©2019 HydroCAD Software Solutions LLC Page 10
Summary for Subcatchment 4: Area 4
Runoff = 2.92 cfs @ 12.09 hrs, Volume= 0.231 af, Depth> 0.33"
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs
Type II 24-hr 1y 24h Rainfall=3.05"
Area (ac) CN Description
8.479 61 >75% Grass cover, Good, HSG B
8.479 100.00% Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
9.1 100 0.0200 0.18 Sheet Flow,
Grass: Short n= 0.150 P2= 3.70"
4.0 506 0.0198 2.11 Shallow Concentrated Flow,
Grassed Waterway Kv= 15.0 fps
13.1 606 Total
Subcatchment 4: Area 4
Hydrograph
.................................................... ❑Runoff
3 12.92 cfs i ::
Type 1124-h r
ly 24h Rainfall=3.05"
Runoff Area=8.479 ac
2- Runoff Volume=02311af_._..
Runoff Depth>0.33"
2 Flow Length=6Q6'
T 1 c� 3�1 min
1- I� cN=61
5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
Time (hours)

20221019_Harnett County_NW CC_Existing Conditions Type 1124-hr 1y24h Rainfall=3.05"
Prepared by HDR, Inc Printed 10/19/2022
HydroCAD® 10.00-25 s/n 11397 ©2019 HydroCAD Software Solutions LLC Page 11
Summary for Reach DO: NCDOT Road Ditch
Inflow Area = 8.479 ac, 0.00% Impervious, Inflow Depth > 0.33" for 1y 24h event
Inflow = 2.92 cfs @ 12.09 hrs, Volume= 0.231 af
Outflow = 2.01 cfs @ 12.35 hrs, Volume= 0.226 af, Atten= 31%, Lag= 15.4 min
Routing by Stor-Ind+Trans method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs
Max. Velocity= 2.10 fps, Min. Travel Time= 9.0 min
Avg. Velocity= 1.20 fps, Avg. Travel Time= 15.7 min
Peak Storage= 1,084 cf @ 12.20 hrs
Average Depth at Peak Storage= 0.42'
Bank-Full Depth= 3.00' Flow Area= 30.0 sf, Capacity= 201.86 cfs
1.00' x 3.00' deep channel, n= 0.035 Earth, dense weeds
Side Slope Z-value= 3.0 '/' Top Width= 19.00'
Length= 1,130.0' Slope= 0.0146 '/'
Inlet Invert= 372.00', Outlet Invert= 355.50'
Reach DO: NCDOT Road Ditch
Hydrograph
❑Inflow
; i
Izsz.ts ❑Outflo w
Inflow Area=8.479 ac
Avg. Flow Depth=0.42'
Max Vel=2.10 fps
1201. fs n=0.035
2—
L=1130.0'
LL _ 1 1 S=0.0146 '/'
iLitY2o1M6cft
0
5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
Time (hours)

20221019_Harnett County_NW CC_Existing Conditions Type 1124-hr 1y24h Rainfall=3.05"
Prepared by HDR, Inc Printed 10/19/2022
HydroCAD® 10.00-25 s/n 11397 ©2019 HydroCAD Software Solutions LLC Page 12
Summary for Reach D1: Draw
Inflow Area = 11.609 ac, 0.00% Impervious, Inflow Depth > 0.24" for 1y 24h event
Inflow = 1.39 cfs @ 12.35 hrs, Volume= 0.230 af
Outflow = 0.76 cfs @ 13.47 hrs, Volume= 0.206 af, Atten= 45%, Lag= 67.2 min
Routing by Stor-Ind+Trans method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs
Max. Velocity= 0.22 fps, Min. Travel Time= 38.1 min
Avg. Velocity= 0.15 fps, Avg. Travel Time= 54.4 min
Peak Storage= 1,745 cf @ 12.84 hrs
Average Depth at Peak Storage= 0.12'
Bank-Full Depth= 3.00' Flow Area= 174.0 sf, Capacity= 252.99 cfs
28.00' x 3.00' deep channel, n= 0.400 Sheet flow: Woods+light brush
Side Slope Z-value= 10.0 '/' Top Width= 88.00'
Length= 500.0' Slope= 0.0620 '/'
Inlet Invert= 316.00', Outlet Invert= 285.00'
Reach D1: Draw
Hydrograph
/ ❑Inflow
I1.39cfs ❑Outflow
Inflow Area=11 .609 ac
Avg. Flow Depth=0.12'
Ad Max Vel 0.22 fps
n=0.400
1076cfs , L=500.0'
S=0.0620 '/'
��,��j < •acity=252.99 cfs
0
5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
Time (hours)

20221019_Harnett County_NW CC_Existing Conditions Type 1124-hr 1y24h Rainfall=3.05"
Prepared by HDR, Inc Printed 10/19/2022
HydroCAD® 10.00-25 s/n 11397 ©2019 HydroCAD Software Solutions LLC Page 13
Summary for Reach D2: Draw
Inflow Area = 5.131 ac, 0.00% Impervious, Inflow Depth > 0.21" for 1y 24h event
Inflow = 0.59 cfs @ 12.26 hrs, Volume= 0.091 af
Outflow = 0.33 cfs @ 13.15 hrs, Volume= 0.084 af, Atten= 44%, Lag= 53.7 min
Routing by Stor-Ind+Trans method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs
Max. Velocity= 0.24 fps, Min. Travel Time= 29.3 min
Avg. Velocity= 0.17 fps, Avg. Travel Time= 42.1 min
Peak Storage= 576 cf @ 12.66 hrs
Average Depth at Peak Storage= 0.10'
Bank-Full Depth= 3.00' Flow Area= 126.0 sf, Capacity= 211.86 cfs
12.00' x 3.00' deep channel, n= 0.400 Sheet flow: Woods+light brush
Side Slope Z-value= 10.0 '/' Top Width= 72.00'
Length= 430.0' Slope= 0.0977 '/'
Inlet Invert= 327.00', Outlet Invert= 285.00'
Reach D2: Draw
Hydrograph
Inflow
0.65-" ss cts ❑Outflow
0.6
Inflow Area=5.131 ac
r
Avg. Flow Depth=0.10'
0.5.'
Vel=0.24 fps
_` n-0.400
Vl - .•
V - .................._.....................:......................................._:................. ............ .......... 033 cfs _......... ............. ............ ......... __._.
0.35= .
Q
0 0.3_' ;,, i C 7 '''
i
i 0
�•!•/ apacity=211 .86 cfs
. ' i ! Z
0.05
5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
Time (hours)

20221019_Harnett County_NW CC_Existing Conditions Type 1124-hr 1y24h Rainfall=3.05"
Prepared by HDR, Inc Printed 10/19/2022
HydroCAD® 10.00-25 s/n 11397 ©2019 HydroCAD Software Solutions LLC Page 14
Summary for Reach D3: Draw
Inflow Area = 1.231 ac, 0.00% Impervious, Inflow Depth > 0.17" for 1y 24h event
Inflow = 0.08 cfs @ 12.29 hrs, Volume= 0.017 af
Outflow = 0.05 cfs @ 13.21 hrs, Volume= 0.016 af, Atten= 38%, Lag= 55.0 min
Routing by Stor-Ind+Trans method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs
Max. Velocity= 0.14 fps, Min. Travel Time= 26.3 min
Avg. Velocity= 0.14 fps, Avg. Travel Time= 26.3 min
Peak Storage= 82 cf @ 12.77 hrs
Average Depth at Peak Storage= 0.02'
Bank-Full Depth= 3.00' Flow Area= 195.0 sf, Capacity= 432.67 cfs
20.00' x 3.00' deep channel, n= 0.400 Sheet flow: Woods+light brush
Side Slope Z-value= 15.0 '/' Top Width= 110.00'
Length= 228.0' Slope= 0.1667 '/'
Inlet Invert= 353.00', Outlet Invert= 315.00'
Reach D3: Draw
Hydrograph
....................»................ ❑Outflow
0.085=' Inflow Area=1 .231 ac
0.08 ''
i..... i t Avg. Flow Depth=0.02'
0.075=' /
...................._ Max
ax a - . fps
0.06= _n 0 400
0.055 " .. 0.05 cf
v 0.05_" 1 %, =L 228 0
c 0.045 � % —
a 0.04 *#� —
...................,...........----....,.....----...........t---...........---- ------........... --............ ....
i .... S 0 1667 '/'
��
0.03= �`��'..
�
0.025 ,, : 1.4:0,0I....
/i"
.._.. II
•
0.01 i
0
6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
Time (hours)

20221019_Harnett County_NW CC_Existing Conditions Type 1124-hr 1y24h Rainfall=3.05"
Prepared by HDR, Inc Printed 10/19/2022
HydroCAD® 10.00-25 s/n 11397 ©2019 HydroCAD Software Solutions LLC Page 15
Summary for Reach D4: Ditch Next to Road
Inflow Area = 8.479 ac, 0.00% Impervious, Inflow Depth > 0.32" for 1y 24h event
Inflow = 2.01 cfs @ 12.35 hrs, Volume= 0.226 af
Outflow = 1.31 cfs @ 12.83 hrs, Volume= 0.216 af, Atten= 35%, Lag= 29.0 min
Routing by Stor-Ind+Trans method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs
Max. Velocity= 0.53 fps, Min. Travel Time= 15.7 min
Avg. Velocity= 0.33 fps, Avg. Travel Time= 25.4 min
Peak Storage= 1,241 cf @ 12.57 hrs
Average Depth at Peak Storage= 0.54'
Bank-Full Depth= 3.00' Flow Area= 36.0 sf, Capacity= 49.87 cfs
3.00' x 3.00' deep channel, n= 0.400 Sheet flow: Woods+light brush
Side Slope Z-value= 3.0 '/' Top Width= 21.00'
Length= 500.0' Slope= 0.0720 '/'
Inlet Invert= 351.00', Outlet Invert= 315.00'
Reach D4: Ditch Next to Road
Hydrograph
-/ ❑Inflow
IDOutflo;........--....:..--...........! i.....--.....-'--........ - ____ �2.01 ors
w
Inflow Area=8.479 ac
Avg. Flow Depth=0.54'
Max Vel=0.53 fps
i 1.31 crs n=0.400
N _
0 0'
S=0.0720 '/'
Capacity=49.87 cfs
0
5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
Time (hours)

20221019_Harnett County_NW CC_Existing Conditions Type 1124-hr 1y24h Rainfall=3.05"
Prepared by HDR, Inc Printed 10/19/2022
HydroCAD® 10.00-25 s/n 11397 ©2019 HydroCAD Software Solutions LLC Page 16
Summary for Reach D5: Draw
Inflow Area = 16.740 ac, 0.00% Impervious, Inflow Depth > 0.21" for 1y 24h event
Inflow = 1.05 cfs @ 13.41 hrs, Volume= 0.290 af
Outflow = 0.73 cfs @ 15.24 hrs, Volume= 0.237 af, Atten= 31%, Lag= 109.8 min
Routing by Stor-Ind+Trans method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs
Max. Velocity= 0.29 fps, Min. Travel Time= 55.7 min
Avg. Velocity= 0.23 fps, Avg. Travel Time= 70.5 min
Peak Storage= 2,436 cf @ 14.31 hrs
Average Depth at Peak Storage= 0.22'
Bank-Full Depth= 3.00' Flow Area= 93.0 sf, Capacity= 120.90 cfs
10.00' x 3.00' deep channel, n= 0.400 Sheet flow: Woods+light brush
Side Slope Z-value= 7.0 '/' Top Width= 52.00'
Length= 982.0' Slope= 0.0570 '/'
Inlet Invert= 285.00', Outlet Invert= 229.00'
Reach D5: Draw
Hydrograph
/ ■Inflow
i.os 11111 ■Outflow
Inflow Area=16.740 ac / _ ..-..-.. ._.-..
Avg. Flow Depth=0.22'
Max Vel=0.29 fps
0 73 cfs .
n=0.400 . '�j,
L=982.0' %j
S=0.0570 'I'
Capacity-120.90 cfs i
5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
Time (hours)

20221019_Harnett County_NW CC_Existing Conditions Type 1124-hr 1y24h Rainfall=3.05"
Prepared by HDR, Inc Printed 10/19/2022
HydroCAD® 10.00-25 s/n 11397 ©2019 HydroCAD Software Solutions LLC Page 17
Summary for Reach D6: Draw
Inflow Area = 9.710 ac, 0.00% Impervious, Inflow Depth > 0.29" for 1y 24h event
Inflow = 1.35 cfs @ 12.84 hrs, Volume= 0.232 of
Outflow = 0.38 cfs @ 17.31 hrs, Volume= 0.119 af, Atten= 72%, Lag= 268.1 min
Routing by Stor-Ind+Trans method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs
Max. Velocity= 0.18 fps, Min. Travel Time= 162.2 min
Avg. Velocity= 0.15 fps, Avg. Travel Time= 186.0 min
Peak Storage= 3,696 cf @ 14.60 hrs
Average Depth at Peak Storage= 0.10'
Bank-Full Depth= 3.00' Flow Area= 159.0 sf, Capacity= 198.54 cfs
20.00' x 3.00' deep channel, n= 0.400 Sheet flow: Woods+light brush
Side Slope Z-value= 11.0 '/' Top Width= 86.00'
Length= 1,720.0' Slope= 0.0500 '/'
Inlet Invert= 315.00', Outlet Invert= 229.00'
Reach D6: Draw
Hydrograph
/ ■Inflow
I 1.35 cfs •Outflow
Inflow Area=9.710 ac
Avg. Flow Depth=0.10' P
MaxVet=0.18 fps / ...................._1......................................._................... ............
1 n=0.400
L=1 ,720.0'
I
Capacity=198.54 cfs ����
0.38 cfs
5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
Time (hours)

20221019_Harnett County_NW CC_Existing Conditions Type 1124-hr 1y24h Rainfall=3.05"
Prepared by HDR, Inc Printed 10/19/2022
HydroCAD® 10.00-25 s/n 11397 ©2019 HydroCAD Software Solutions LLC Page 18
Summary for Reach D7: Outfall to Avent Creek
Inflow Area = 26.450 ac, 0.00% Impervious, Inflow Depth > 0.16" for 1y 24h event
Inflow = 0.90 cfs @ 16.45 hrs, Volume= 0.356 af
Outflow = 0.90 cfs @ 16.70 hrs, Volume= 0.339 af, Atten= 0%, Lag= 14.9 min
Routing by Stor-Ind+Trans method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs
Max. Velocity= 0.24 fps, Min. Travel Time= 9.2 min
Avg. Velocity= 0.20 fps, Avg. Travel Time= 10.9 min
Peak Storage= 495 cf @ 16.55 hrs
Average Depth at Peak Storage= 0.20'
Bank-Full Depth= 3.00' Flow Area= 117.0 sf, Capacity= 132.42 cfs
18.00' x 3.00' deep channel, n= 0.400 Sheet flow: Woods+light brush
Side Slope Z-value= 7.0 '/' Top Width= 60.00'
Length= 130.0' Slope= 0.0385 '/'
Inlet Invert= 229.00', Outlet Invert= 224.00'
Reach D7: Outfall to Avent Creek
Hydrograph
` ❑Inflow
1
I oso crs ❑Outflow
Inflow Area=26.450 ac 0.90
;���i���
Avg. Flow Depth=0.20'
Max Vel=0.24 fps
n=0.400
L=130.0
S=0.0385 '/'
Capacity=132.42 cfs
5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
Time (hours)

20221019_Harnett County_NW CC_Existing Conditions Type 1124-hr 1y24h Rainfall=3.05"
Prepared by HDR, Inc Printed 10/19/2022
HydroCAD® 10.00-25 s/n 11397 ©2019 HydroCAD Software Solutions LLC Page 19
Summary for Pond C 1: Existing Culvert
Inflow Area = 8.479 ac, 0.00% Impervious, Inflow Depth > 0.32" for 1y 24h event
Inflow = 2.01 cfs @ 12.35 hrs, Volume= 0.226 af
Outflow = 2.01 cfs @ 12.35 hrs, Volume= 0.226 af, Atten= 0%, Lag= 0.0 min
Primary = 2.01 cfs @ 12.35 hrs, Volume= 0.226 af
Secondary= 0.00 cfs @ 5.00 hrs, Volume= 0.000 af
Routing by Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs
Peak Elev= 355.29' @ 12.35 hrs
Flood Elev= 357.00'
Device Routing Invert Outlet Devices _
#1 Primary 354.50' 12.0" Round Culvert
L= 137.0' RCP, end-section conforming to fill, Ke= 0.500
Inlet/Outlet Invert= 354.50' /351.00' S= 0.0255 '/' Cc= 0.900
n= 0.012 Concrete pipe, finished, Flow Area= 0.79 sf
#2 Secondary 357.00' 50.0' long x 100.0' breadth Broad-Crested Rectangular Weir
Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60
Coef. (English) 2.68 2.70 2.70 2.64 2.63 2.64 2.64 2.63
Primary OutFlow Max=2.01 cfs @ 12.35 hrs HW=355.29' (Free Discharge)
L1=Culvert (Inlet Controls 2.01 cfs @ 3.02 fps)
Secondary OutFlow Max=0.00 cfs @ 5.00 hrs HW=354.50' (Free Discharge)
L2=Broad-Crested Rectangular Weir ( Controls 0.00 cfs)
Pond C 1: Existing Culvert
Hydrograph
❑Inflow
. . . . . . .2.01 cfs l- El Outflow
z.o1cfs'' Inflow Area=8.479 ac ❑Primary
z..cfs ❑Secondary
2- / I
Peak Elev=355.29'
IN ,r
LL 1
•
0 „
0 }'(C��tS �lSsf44% ItSS�tSS ����
5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
Time (hours)

20221019_Harnett County_NW CC_Existing Condition Type 1124-hr 25y 24h Rainfall=6.75"
Prepared by HDR, Inc Printed 10/19/2022
HydroCAD® 10.00-25 s/n 11397 ©2019 HydroCAD Software Solutions LLC Page 20
Time span=5.00-20.00 hrs, dt=0.05 hrs, 301 points
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN
Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method
Subcatchment 1: Area 1 Runoff Area=11.609 ac 0.00% Impervious Runoff Depth>2.00"
Flow Length=1,164' Tc=28.9 min CN=58 Runoff=21.62 cfs 1.937 af
Subcatchment 2: Area 2 Runoff Area=5.131 ac 0.00% Impervious Runoff Depth>1.92"
Flow Length=700' Tc=22.2 min CN=57 Runoff=10.82 cfs 0.822 af
Subcatchment 3: Area 3 Runoff Area=1.231 ac 0.00% Impervious Runoff Depth>1.75"
Flow Length=326' Tc=22.4 min CN=55 Runoff=2.31 cfs 0.180 af
Subcatchment 4: Area 4 Runoff Area=8.479 ac 0.00% Impervious Runoff Depth>2.28"
Flow Length=606' Tc=13.1 min CN=61 Runoff=28.83 cfs 1.614 af
Reach DO: NCDOT Road Ditch Avg. Flow Depth=1.30' Max Vel=4.01 fps Inflow=28.83 cfs 1.614 af
n=0.035 L=1,130.0' S=0.0146 '/' Capacity=201.86 cfs Outflow=25.05 cfs 1.601 af
Reach D1: Draw Avg. Flow Depth=0.74' Max Vel=0.67 fps Inflow=21.62 cfs 1.937 af
n=0.400 L=500.0' S=0.0620 '/' Capacity=252.99 cfs Outflow=17.57 cfs 1.884 af
Reach D2: Draw Avg. Flow Depth=0.66' Max Vel=0.72 fps Inflow=10.82 cfs 0.822 af
n=0.400 L=430.0' S=0.0977 '/' Capacity=211.86 cfs Outflow=8.69 cfs 0.804 af
Reach D3: Draw Avg. Flow Depth=0.19' Max Vel=0.46 fps Inflow=2.31 cfs 0.180 af
n=0.400 L=228.0' S=0.1667 '/' Capacity=432.67 cfs Outflow=1.98 cfs 0.176 af
Reach D4: Ditch Next to Road Avg. Flow Depth=2.05' Max Vel=1.11 fps Inflow=25.05 cfs 1.601 af
n=0.400 L=500.0' S=0.0720 '/' Capacity=49.87 cfs Outflow=20.51 cfs 1.579 af
Reach D5: Draw Avg. Flow Depth=1.23' Max Vel=0.79 fps Inflow=24.94 cfs 2.688 af
n=0.400 L=982.0' S=0.0570 '/' Capacity=120.90 cfs Outflow=17.88 cfs 2.575 af
Reach D6: Draw Avg. Flow Depth=0.59' Max Vel=0.50 fps Inflow=22.48 cfs 1.755 af
n=0.400 L=1,720.0' S=0.0500 '/' Capacity=198.54 cfs Outflow=7.83 cfs 1.549 af
Reach D7: Outfall to Avent Creek Avg. Flow Depth=1.15' Max Vel=0.67 fps Inflow=19.98 cfs 4.125 af
n=0.400 L=130.0' S=0.0385 '/' Capacity=132.42 cfs Outflow=19.92 cfs 4.094 af
Pond C 1: Existing Culvert Peak Elev=357.27' Inflow=25.05 cfs 1.601 af
Primary=5.70 cfs 1.128 af Secondary=19.35 cfs 0.473 af Outflow=25.05 cfs 1.601 af
Total Runoff Area = 26.450 ac Runoff Volume =4.553 af Average Runoff Depth = 2.07"
100.00% Pervious = 26.450 ac 0.00% Impervious = 0.000 ac

20221019_Harnett County_NW CC_Existing Condition Type 1124-hr 25y 24h Rainfall=6.75"
Prepared by HDR, Inc Printed 10/19/2022
HydroCAD® 10.00-25 s/n 11397 ©2019 HydroCAD Software Solutions LLC Page 21
Summary for Subcatchment 1: Area 1
Runoff = 21.62 cfs @ 12.25 hrs, Volume= 1.937 af, Depth> 2.00"
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs
Type II 24-hr 25y 24h Rainfall=6.75"
Area (ac) CN Description
5.230 61 >75% Grass cover, Good, HSG B
6.379 55 Woods, Good, HSG B
11.609 58 Weighted Average
11.609 100.00% Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
13.3 100 0.0200 0.13 Sheet Flow,
Grass: Dense n= 0.240 P2= 3.70"
15.6 1,064 0.0520 1.14 Shallow Concentrated Flow,
Woodland Kv= 5.0 fps
28.9 1,164 Total
Subcatchment 1: Area 1
Hydrograph
24=' :.............................................................................................................I.........................................
........ ..._i.
:............
■Runoff
22=' :........
21_ ; . ......_........_..._.............._............._............_.............._............_......_„...._........................ pe.....I1....24-O r
25y �4h �a�n#all-6 �'S
..._.............._1............_......_1....._............._i.........__
r
0
Ru ii noff Area �1.609 LI ;ac
15=' ,.......... I - Ru1noff..Volume=1.937 af.......
u 13- :.......... ........ ... ;.._._ .......__< ...._ .....;._--_........ ,.. ...... `
il 1 I 0
Runof# De th 2 QO
11 :
LT! FIQw.....Le.n. : th011 4'
TC 28 9 nitrt
O N=15
5 .......... ..... L....
q
! I f II 1 -E . 1- [ ! ; r
L
......... ....
5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
Time (hours)

20221019_Harnett County_NW CC_Existing Condition Type 1124-hr 25y 24h Rainfall=6.75"
Prepared by HDR, Inc Printed 10/19/2022
HydroCAD® 10.00-25 s/n 11397 ©2019 HydroCAD Software Solutions LLC Page 22
Summary for Subcatchment 2: Area 2
Runoff = 10.82 cfs @ 12.17 hrs, Volume= 0.822 af, Depth> 1.92"
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs
Type II 24-hr 25y 24h Rainfall=6.75"
Area (ac) CN Description
1.483 61 >75% Grass cover, Good, HSG B
3.648 55 Woods, Good, HSG B
5.131 57 Weighted Average
5.131 100.00% Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
9.1 100 0.0200 0.18 Sheet Flow,
Grass: Short n= 0.150 P2= 3.70"
13.1 600 0.0233 0.76 Shallow Concentrated Flow,
Woodland Kv= 5.0 fps
22.2 700 Total
Subcatchment 2: Area 2
Hydrograph
12
■Runoff
10.82 cfs_..-..-
11_
- - Type III 24-hr.
107 25y 24h Rainfall=6.75"
9_
..._.............._.,............_......_....._.............._.......... Runoff -
Area-5.131 ac
8_
Runoff Volume=0.822 af
N 7-
2 : 1, 1. I 0
Runoff Depth>1.92"_._..
3 6_ • Flow a rgt =700'
_ . Tc=22 2 m'rn.
4 I I •
3_
2-
5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
Time (hours)

20221019_Harnett County_NW CC_Existing Condition Type 1124-hr 25y 24h Rainfall=6.75"
Prepared by HDR, Inc Printed 10/19/2022
HydroCAD® 10.00-25 s/n 11397 ©2019 HydroCAD Software Solutions LLC Page 23
Summary for Subcatchment 3: Area 3
Runoff = 2.31 cfs @ 12.17 hrs, Volume= 0.180 af, Depth> 1.75"
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs
Type II 24-hr 25y 24h Rainfall=6.75"
Area (ac) CN Description
1.231 55 Woods, Good, HSG B
1.231 100.00% Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
20.0 100 0.0200 0.08 Sheet Flow,
Woods: Light underbrush n= 0.400 P2= 3.70"
2.4 226 0.0973 1.56 Shallow Concentrated Flow,
Woodland Kv= 5.0 fps
22.4 326 Total
Subcatchment 3: Area 3
Hydrograph
D Runoff
- 1 2.3l cfs I
i
Type 124-h r
2_ 025y 24h Rainfall=6.75
- Runoff Area=1 .231 ac
- Runoff Volume=0.180 of
'3 - / Runoff Depth>1.75"
F- , t ,' , 1low L.e_ngth=3261
1 Tc=22.4 min
. : . , : . : CN-55
0 ,iiiiiiiiiiiiiiiiiiiiiiiiiiiiiif ��
5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
Time (hours)

20221019_Harnett County_NW CC_Existing Condition Type 1124-hr 25y 24h Rainfall=6.75"
Prepared by HDR, Inc Printed 10/19/2022
HydroCAD® 10.00-25 s/n 11397 ©2019 HydroCAD Software Solutions LLC Page 24
Summary for Subcatchment 4: Area 4
Runoff = 28.83 cfs @ 12.06 hrs, Volume= 1.614 af, Depth> 2.28"
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs
Type II 24-hr 25y 24h Rainfall=6.75"
Area (ac) CN Description
8.479 61 >75% Grass cover, Good, HSG B
8.479 100.00% Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
9.1 100 0.0200 0.18 Sheet Flow,
Grass: Short n= 0.150 P2= 3.70"
4.0 506 0.0198 2.11 Shallow Concentrated Flow,
Grassed Waterway Kv= 15.0 fps
13.1 606 Total
Subcatchment 4: Area 4
Hydrograph
32="" 1 i I I I I ■Runoff
30 i iiii1J2883cfslii
28_ , 11111i01 Type II 24-hr
26= _ ��.........
2Sy 24h Rainfall-6.75
24
Runoff Area=8.479 ac.
22
20_ Runoff,Vol ume=1....fi1..._4.:._af...........
w 18=' .........iit [ ii _Runoff Depfh�2.2
8"
3 16_
o _
I
ow
� 14
................ ....en g... .......................... ..........
121 Tc=13..1......m.i.n0 .........
I
i
EN=61 .
8
iiii
4= .
5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
Time (hours)

20221019_Harnett County_NW CC_Existing Condition Type 1124-hr 25y 24h Rainfall=6.75"
Prepared by HDR, Inc Printed 10/19/2022
HydroCAD® 10.00-25 s/n 11397 ©2019 HydroCAD Software Solutions LLC Page 25
Summary for Reach DO: NCDOT Road Ditch
Inflow Area = 8.479 ac, 0.00% Impervious, Inflow Depth > 2.28" for 25y 24h event
Inflow = 28.83 cfs @ 12.06 hrs, Volume= 1.614 af
Outflow = 25.05 cfs @ 12.19 hrs, Volume= 1.601 af, Atten= 13%, Lag= 8.1 min
Routing by Stor-Ind+Trans method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs
Max. Velocity= 4.01 fps, Min. Travel Time= 4.7 min
Avg. Velocity = 1.79 fps, Avg. Travel Time= 10.5 min
Peak Storage= 7,216 cf @ 12.11 hrs
Average Depth at Peak Storage= 1.30'
Bank-Full Depth= 3.00' Flow Area= 30.0 sf, Capacity= 201.86 cfs
1.00' x 3.00' deep channel, n= 0.035 Earth, dense weeds
Side Slope Z-value= 3.0 '/' Top Width= 19.00'
Length= 1,130.0' Slope= 0.0146 '/'
Inlet Invert= 372.00', Outlet Invert= 355.50'
Reach DO: NCDOT Road Ditch
Hydrograph
32= /.. aas ❑Outflow
ill s
❑Inflow
......._:....
3 Inflow Area=8.479 ac
26 I I ir ,25.05 cfs vg.... Flo*..Dept 01
.301
2a Q1=4
Max = '-... a
22=
w 18 L='1,_'130 .0
. . . . . .
3 16 �a
- .0 ..a. a..
LL 14_' 1 4
81
12z. 4............ Ca.pmcity=.2U1... 6....cfs....
5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
Time (hours)

20221019_Harnett County_NW CC_Existing Condition Type 1124-hr 25y 24h Rainfall=6.75"
Prepared by HDR, Inc Printed 10/19/2022
HydroCAD® 10.00-25 s/n 11397 ©2019 HydroCAD Software Solutions LLC Page 26
Summary for Reach D1: Draw
Inflow Area = 11.609 ac, 0.00% Impervious, Inflow Depth > 2.00" for 25y 24h event
Inflow = 21.62 cfs @ 12.25 hrs, Volume= 1.937 af
Outflow = 17.57 cfs @ 12.61 hrs, Volume= 1.884 af, Atten= 19%, Lag= 21.2 min
Routing by Stor-Ind+Trans method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs
Max. Velocity= 0.67 fps, Min. Travel Time= 12.5 min
Avg. Velocity = 0.29 fps, Avg. Travel Time= 28.7 min
Peak Storage= 13,185 cf© 12.40 hrs
Average Depth at Peak Storage= 0.74'
Bank-Full Depth= 3.00' Flow Area= 174.0 sf, Capacity= 252.99 cfs
28.00' x 3.00' deep channel, n= 0.400 Sheet flow: Woods+light brush
Side Slope Z-value= 10.0 '/' Top Width= 88.00'
Length= 500.0' Slope= 0.0620 '/'
Inlet Invert= 316.00', Outlet Invert= 285.00'
Reach D1: Draw
Hydrograph
24- t ......
I 21.62cfsI t
•Inflow
■Outflow
t
' t
22;';' <._.... .. �. 1. c w...-Area=- 1.$0 � ...
201 i l h*0 Avg Flow;Dept :1 '
1&. 0 757cf l~
1 s
Max
.67 fin
13= a....__ L=.
... 0.0I.O....
3121i /1IIIIII
..,.... :::: ::::::::: -........._...-._:.0620 'I'...._._.
1
ø *4
5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
Time (hours)

20221019_Harnett County_NW CC_Existing Condition Type 1124-hr 25y 24h Rainfall=6.75"
Prepared by HDR, Inc Printed 10/19/2022
HydroCAD® 10.00-25 s/n 11397 ©2019 HydroCAD Software Solutions LLC Page 27
Summary for Reach D2: Draw
Inflow Area = 5.131 ac, 0.00% Impervious, Inflow Depth > 1.92" for 25y 24h event
Inflow = 10.82 cfs @ 12.17 hrs, Volume= 0.822 of
Outflow = 8.69 cfs @ 12.45 hrs, Volume= 0.804 af, Atten= 20%, Lag= 17.1 min
Routing by Stor-Ind+Trans method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs
Max. Velocity= 0.72 fps, Min. Travel Time= 10.0 min
Avg. Velocity= 0.32 fps, Avg. Travel Time= 22.6 min
Peak Storage= 5,253 cf @ 12.28 hrs
Average Depth at Peak Storage= 0.66'
Bank-Full Depth= 3.00' Flow Area= 126.0 sf, Capacity= 211.86 cfs
12.00' x 3.00' deep channel, n= 0.400 Sheet flow: Woods+light brush
Side Slope Z-value= 10.0 '/' Top Width= 72.00'
Length= 430.0' Slope= 0.0977 '/'
Inlet Invert= 327.00', Outlet Invert= 285.00'
Reach D2: Draw
Hydrograph
12= .........................................._.. , ❑
❑Inflow
....110.82 cfs : Outflow
11-'" ± Inflow Area=5.131 ac
,0= 'Avg. Flow Depth=0.66'
Max ,Vel=0.72 fps
n=0.400
S=0.0977 'I'
4=: ........._............._....................................._...................._........ i. •1' 1 _._.. Capacity=211.86 cfs
3- s
. i..... •,,I��
2
PI
0 �Sftf�
5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
Time (hours)

20221019_Harnett County_NW CC_Existing Condition Type 1124-hr 25y 24h Rainfall=6.75"
Prepared by HDR, Inc Printed 10/19/2022
HydroCAD® 10.00-25 s/n 11397 ©2019 HydroCAD Software Solutions LLC Page 28
Summary for Reach D3: Draw
Inflow Area = 1.231 ac, 0.00% Impervious, Inflow Depth > 1.75" for 25y 24h event
Inflow = 2.31 cfs @ 12.17 hrs, Volume= 0.180 af
Outflow = 1.98 cfs @ 12.41 hrs, Volume= 0.176 af, Atten= 15%, Lag= 14.2 min
Routing by Stor-Ind+Trans method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs
Max. Velocity= 0.46 fps, Min. Travel Time= 8.2 min
Avg. Velocity= 0.19 fps, Avg. Travel Time= 19.7 min
Peak Storage= 982 cf @ 12.27 hrs
Average Depth at Peak Storage= 0.19'
Bank-Full Depth= 3.00' Flow Area= 195.0 sf, Capacity= 432.67 cfs
20.00' x 3.00' deep channel, n= 0.400 Sheet flow: Woods+light brush
Side Slope Z-value= 15.0 '/' Top Width= 110.00'
Length= 228.0' Slope= 0.1667 '/'
Inlet Invert= 353.00', Outlet Invert= 315.00'
Reach D3: Draw
Hydrograph
/ ❑Inflow
j 1 2.31 cfs I ❑Outflow
Inflow Area=1 .231 ac
198cfs i Avg. Flow Depth=0.19'
2 ' i
�� ' Max Vel=0.46 fps
I/ n=0.400
/�0 L=228.0
LL �� =0.1667 '/'
# ,
� Capacity=432.67 cfs
4.
5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
Time (hours)

20221019_Harnett County_NW CC_Existing Condition Type 1124-hr 25y 24h Rainfall=6.75"
Prepared by HDR, Inc Printed 10/19/2022
HydroCAD® 10.00-25 s/n 11397 ©2019 HydroCAD Software Solutions LLC Page 29
Summary for Reach D4: Ditch Next to Road
Inflow Area = 8.479 ac, 0.00% Impervious, Inflow Depth > 2.27" for 25y 24h event
Inflow = 25.05 cfs @ 12.19 hrs, Volume= 1.601 af
Outflow = 20.51 cfs © 12.41 hrs, Volume= 1.579 af, Atten= 18%, Lag= 12.8 min
Routing by Stor-Ind+Trans method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs
Max. Velocity= 1.11 fps, Min. Travel Time= 7.5 min
Avg. Velocity = 0.50 fps, Avg. Travel Time= 16.7 min
Peak Storage= 9,343 cf @ 12.28 hrs
Average Depth at Peak Storage= 2.05'
Bank-Full Depth= 3.00' Flow Area= 36.0 sf, Capacity= 49.87 cfs
3.00' x 3.00' deep channel, n= 0.400 Sheet flow: Woods+light brush
Side Slope Z-value= 3.0 '/' Top Width= 21.00'
Length= 500.0' Slope= 0.0720 '/'
Inlet Invert= 351.00', Outlet Invert= 315.00'
Reach D4: Ditch Next to Road
Hydrograph
t......... ..-
28 I ❑Outflow
cfs I
D Inflow
26- 1n`flow A rea=8.479 ac
24-
22- .... 1 cfs I _
•
Avg Flow' Depth=2.05'
20- ,
Max Vel=1.11 fps
•
18- . ; 0 n=p.. ....__
.400
w 16-
3 14-
O0''I'
I 01 I a 12_
S�7 7
= i
10_:' t ._.
Da_ act_ C_ 149 7O#s•
s-'
•
5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
Time (hours)

20221019_Harnett County_NW CC_Existing Condition Type 1124-hr 25y 24h Rainfall=6.75"
Prepared by HDR, Inc Printed 10/19/2022
HydroCAD® 10.00-25 s/n 11397 ©2019 HydroCAD Software Solutions LLC Page 30
Summary for Reach D5: Draw
Inflow Area = 16.740 ac, 0.00% Impervious, Inflow Depth > 1.93" for 25y 24h event
Inflow = 24.94 cfs @ 12.56 hrs, Volume= 2.688 af
Outflow = 17.88 cfs @ 13.17 hrs, Volume= 2.575 af, Atten= 28%, Lag= 36.2 min
Routing by Stor-Ind+Trans method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs
Max. Velocity= 0.79 fps, Min. Travel Time= 20.8 min
Avg. Velocity= 0.42 fps, Avg. Travel Time= 38.6 min
Peak Storage= 22,363 cf @ 12.82 hrs
Average Depth at Peak Storage= 1.23'
Bank-Full Depth= 3.00' Flow Area= 93.0 sf, Capacity= 120.90 cfs
10.00' x 3.00' deep channel, n= 0.400 Sheet flow: Woods+light brush
Side Slope Z-value= 7.0 '/' Top Width= 52.00'
Length= 982.0' Slope= 0.0570 '/'
Inlet Invert= 285.00', Outlet Invert= 229.00'
Reach D5: Draw
Hydrograph
..... ._.... + ..... 1
/ I ■Outflo
O Inflow
zasa�s I
w
26- In ow Area=16. 40` ac ,
24—'
vg....Flow.... .Qp
20=' ,,:
Max VeI 0.79 fps ,.
........ ? I zss of5
18
: 0 n .�0.0....._1....
N
.
C
LL 12 S00.0a77a._���.....-? ..... +..... ;� .......
i
Capacity 120.90 cfs oi I
ivipr
8 r I I I 1,
5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
Time (hours)

20221019_Harnett County_NW CC_Existing Condition Type 1124-hr 25y 24h Rainfall=6.75"
Prepared by HDR, Inc Printed 10/19/2022
HydroCAD® 10.00-25 s/n 11397 ©2019 HydroCAD Software Solutions LLC Page 31
Summary for Reach D6: Draw
Inflow Area = 9.710 ac, 0.00% Impervious, Inflow Depth > 2.17" for 25y 24h event
Inflow = 22.48 cfs @ 12.41 hrs, Volume= 1.755 af
Outflow = 7.83 cfs © 13.76 hrs, Volume= 1.549 af, Atten= 65%, Lag= 81.3 min
Routing by Stor-Ind+Trans method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs
Max. Velocity= 0.50 fps, Min. Travel Time= 56.9 min
Avg. Velocity = 0.29 fps, Avg. Travel Time= 99.6 min
Peak Storage= 26,756 cf© 12.81 hrs
Average Depth at Peak Storage= 0.59'
Bank-Full Depth= 3.00' Flow Area= 159.0 sf, Capacity= 198.54 cfs
20.00' x 3.00' deep channel, n= 0.400 Sheet flow: Woods+light brush
Side Slope Z-value= 11.0 '/' Top Width= 86.00'
Length= 1,720.0' Slope= 0.0500 '/'
Inlet Invert= 315.00', Outlet Invert= 229.00'
7%.....................%%%%. **".....,
Reach D6: Draw
Hydrograph
•Inflow
ai
■Outflow
. :. .. ,.
:- � Inflow Area=910 ac
;
20=
i-.. ..-..-.. Avg:::::Flow`:Depth=O;59`:..
,8= 1 Max VeI=0 50 fps
n=!0
.400' ..-• ' I i : i 0 1 I
13=; .... ........ : ........... ;.-..-.. ..-..-.. ..-..-..-..-.._; : 4 1 =1,7
12=.
:
10 ?
I9- +..................._p....................3.............._ 17.83 cfs —
I i
21 7 ,,/..:1 , A
0
5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
Time (hours)

20221019_Harnett County_NW CC_Existing Condition Type 1124-hr 25y 24h Rainfall=6.75"
Prepared by HDR, Inc Printed 10/19/2022
HydroCAD® 10.00-25 s/n 11397 ©2019 HydroCAD Software Solutions LLC Page 32
Summary for Reach D7: Outfall to Avent Creek
Inflow Area = 26.450 ac, 0.00% Impervious, Inflow Depth > 1.87" for 25y 24h event
Inflow = 19.98 cfs @ 13.49 hrs, Volume= 4.125 of
Outflow = 19.92 cfs © 13.58 hrs, Volume= 4.094 af, Atten= 0%, Lag= 5.5 min
Routing by Stor-Ind+Trans method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs
Max. Velocity= 0.67 fps, Min. Travel Time= 3.3 min
Avg. Velocity = 0.40 fps, Avg. Travel Time= 5.4 min
Peak Storage= 3,890 cf @ 13.53 hrs
Average Depth at Peak Storage= 1.15'
Bank-Full Depth= 3.00' Flow Area= 117.0 sf, Capacity= 132.42 cfs
18.00' x 3.00' deep channel, n= 0.400 Sheet flow: Woods+light brush
Side Slope Z-value= 7.0 '/' Top Width= 60.00'
Length= 130.0' Slope= 0.0385 '/'
Inlet Invert= 229.00', Outlet Invert= 224.00'
Reach D7: Outfall to Avent Creek
Hydrograph
/ 111rni 111 0 Inflow
22= ;' :......................................._;,...................._....................1..................._.................... .....................:..._.._.. 19.98 cfs ... ............. ............ ............. ............. ............ ............__. ❑Outflow
I
20° Inflow Area-426 450' ac )1992c,� :::::::: ::::::::::: ::::: :::::::::
19'_' f A
Avg. Flow Depth=1.15 /r/I
iiii
18'_' //�
MaxVel Q.6 f 's
15=' i
144 n0.400 1 ,
.13=
...... .-
12= L , 13o.0I 0 �j
1 1091:::.<.: St7-0.038$ 'I' I- I 1 NI
ir 320 8' iiii
Capscty12 4 cfsj��,i
�� �''0
10 /AV
1;14,'
5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
Time (hours)

20221019_Harnett County_NW CC_Existing Condition Type 1124-hr 25y 24h Rainfall=6.75"
Prepared by HDR, Inc Printed 10/19/2022
HydroCAD® 10.00-25 s/n 11397 ©2019 HydroCAD Software Solutions LLC Page 33
Summary for Pond C 1: Existing Culvert
Inflow Area = 8.479 ac, 0.00% Impervious, Inflow Depth > 2.27" for 25y 24h event
Inflow = 25.05 cfs @ 12.19 hrs, Volume= 1.601 af
Outflow = 25.05 cfs @ 12.19 hrs, Volume= 1.601 af, Atten= 0%, Lag= 0.0 min
Primary = 5.70 cfs @ 12.19 hrs, Volume= 1.128 af
Secondary= 19.35 cfs @ 12.19 hrs, Volume= 0.473 af
Routing by Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs
Peak Elev= 357.27' @ 12.19 hrs
Flood Elev= 357.00'
Device Routing Invert Outlet Devices _
#1 Primary 354.50' 12.0" Round Culvert
L= 137.0' RCP, end-section conforming to fill, Ke= 0.500
Inlet/Outlet Invert= 354.50' /351.00' S= 0.0255 '/' Cc= 0.900
n= 0.012 Concrete pipe, finished, Flow Area= 0.79 sf
#2 Secondary 357.00' 50.0' long x 100.0' breadth Broad-Crested Rectangular Weir
Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60
Coef. (English) 2.68 2.70 2.70 2.64 2.63 2.64 2.64 2.63
Primary OutFlow Max=5.70 cfs @ 12.19 hrs HW=357.27' (Free Discharge)
L1=Culvert (Inlet Controls 5.70 cfs @ 7.26 fps)
Secondary OutFlow Max=19.13 cfs @ 12.19 hrs HW=357.27' (Free Discharge)
L2=Broad-Crested Rectangular Weir (Weir Controls 19.13 cfs @ 1.40 fps)
Pond C 1: Existing Culvert
Hydrograph
•Inflow
25.05////:
cfs I ❑Outflow
I s
28= :' 0s- Inflow;Area= .9...ac......... o se Secondary
26=: :. Pear v!e ~357 27'
24 -..
22_'..
20_. 19.35 cfs
18
w 16=
14_ :
r'
12='
10
8= _
6- �j��� ,i///////////Z
5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
Time (hours)

Harnett County Solid Waste Department I Stormwater Permit Application—October 2024 r)�
Attachment D.2—Post-Development Calculations
D . 2
Attachment D.2 — Post-
Development Calculations

Harnett County Solid Waste Department I Stormwater Permit Application—October 2024 01
Attachment D.2—Post-Development Calculations
This page intentionally left blank.

1 2 3 4 5 6 7 8
Y
irr".........r
N
Aji ill o syy D
m
LEGEND:
EXISTING CONTOURS
LOC LIMITS OF CONSTRUCTION
�yo
/36p BUFFER ZONE c
APPROXIMATE EDGE OF TREE LINE
ASS I =--- G911 T.WFR RADIUS
r 335f h 3SS M TOWER FENCG
ADJAC NT PUBLIC ROW
350�1 AREA 1:9.848 AC
"" 6"WAT RMAIN
50'BUFFE' - 3gs \ TIME TO CONCENTRATION
_ 100 LF SHEET FLOW
40111,4
AIII I � 1`?S� 827 LF SHALLOW CONC .440400
�46 ''',0N \
, 1:
E911 COMMUNICATIO_ �rtagolf
_�� 355�355
v ExisJl' NOF ce uE�N '—,L_vf� 8 t ONTBUFFS• fr„,,c,.„4,4„ r------
346
w w 30 DIVERSION DITCH(00) �/ PROPERTY LIN �
ail` 3 25V 24H MAX VELOCITY 517 FTIS y AREA 4 DRAINS TO EXISTING I �l
"2 - // h , '/ NCDOT ROW 6WALE NO — 3
O O / p / ,y IMPROVEMENTS TO BE MADE Sp
iiii
3p S 3j �� / n O 3S �� yo I TIME
SO* 7 60 CONCENTRATION 0 SHALLOW LOW ' IS `S
\I 295 p3 p s 50'BUFFS-1 �C/ � 2 I 100 LF SHEET FLOW
290 a % "<5. M��...,t(OVA, %'�i° c M .w
265 O 'iSL PROPERTY LINE AREA 1.1:1.761 A., K O
in M\ �/ � /' TIME TO CONCENTRATION t I W-
27528O 71(_?'
�ryh � 186100SHALLOW CO C V TIME TO CONCENTRAT AC ION ON M I ¢o
26 !I N '.alli��ll/ �O 1751LF SHALLOW FCONCLOW p
?gyp— �I.
S_ O CSWALE SiaSa�y.S�O ov'w ( I . �� I�k - ''‘ aD O \ 2ELOCITY611OdwSanOr�9� 320 0 \33US \ �O 25V 24H MAX VELOCITVACCESS DRIVE SWALE(599 FT/S ' 1t� � �ry4f 315 \ !STING 6-INCHNNN310 _ a M // �:..",_ �o.___ i WATER MAN `�"➢v �-
lii \ y, \� I J// ^ ,ASS T.... \ � :.-:7::. I 7. a�� \\ OV/
'..�li', I�o w �305 �E tit, .._.._. ..../ '-'._ / 1'�N 9 ;. 3'.1. AC ., \\\ Y\ ONTRION O,',�c5)°)\‘ 30p �, ' 100 LF SHEET FLOW\ '\ �� j&y- B
a N 9 2 290 ,�� I - 220 LF SHALLOW CONC f• a
a 'S ',• n `. \ PR\ \ it/iPLAUTLET CED FOR IMPRION TO BE
CULVERT Y� rv��ya�a� 28s � :2@5 ''�o ����,� �3�55 `���50
s 2T0 215 o "S / \340 —_3q3 "il
S AREA 4 AND 5 DRAIN TO U`
Al T.
M 3 �I EXISTING NCDOT ROW
N M "+ CSWALE(S2) 3 d `, SWALE NO IMPROVEMENTS
h N 265 ul '70 25Y 24H MAX VELOCITY 5.98 FT/S\� 3$ Q ` TO BE MADE/ p
ry � M 32s �� 325 dp �h �
, 3 320 �� 34��
i6 _ / �S�
423 N/1?
y
�SO� ry0 —310 ,51. <1 o
\ i1` N Nit, 06 "� 3s 1
aS N 305 b
D o w 315 �
a�N acyo � N i'3,5.
\ �'`,N N o �n
300 310 I�
N a�0 1
1
1t a:aSS o 295 305 Z'Itli
AVENTS CREEK h 2gS 2\ 29S3p0 0oMli
Flo A
— NTIRE SITE DRAINS THROUGH NATURAL 290
irit. CHANNELS IN DRAWS AND INTO ADVENT CREEK h
2>p �285 - N NOTES:
0.0:4 kitk
s \ p
a \ 2 25g 60
S 280 i�� /ry°0 II 1. EXISTING TOPOGRAPHY AND PROPERTY LINES OBTAINED FROM
S 275 ' HARNETT COUNTY GIs.
�) _250 270 rt.
33p 2. PROPERTY BOUNDARY SURVEY COMPLETED BY BENTON W.
e
ry 6 ��255 -- ^�ZgS� \ DEWARE AND ASSOCIATES,APRIL 30,2019.
cN T'S,�,do ph p ?- �60 /
'L ryy 65 Z60� / 0/2228 � 32S 3. CONDITIONAL USE PERMIT#BA-CU-18-18 APPROVED 6/11/18.
0.
PROJECT MANAGER J.MURRAY,PE
PROJECT ENGINEER A.MCGREW,PE Harnett PROPOSED CONDITIONS
$ HDR Engineering,Inc.of the Carolinas �/Th COUNTY HYDROCAD MODEL
DRAWN BY A.MCGREW,PE
N.C.B.E.L.S.License Number:F-0116 NORTH CAROLINA KEY
'';' IM) strong roots•new growth
555 Fayetteville Street,Suite 900 HARNETT COUNTY
919.32.6 00C 05/2024 ISSUED FOR BIDDING
Raleigh,NC 7601 B 01/2023 REVISED BASED ON REVIEWER COMMENTS 0 1" 2' FILENAME OOG-02.dwg
Z A 10/2022 ISSUED FOR PERMITTING NORTHWEST CONVENIENCE CENTER SHEET±
ISSUE DATE DESCRIPTION PROJECT NUMBER 10354670 SCALE 1"=125' oOV�01
HARNETT COUNTY NORTH CAROLINA

K 4 )
Area 4 DO
O
NCDOT Ro d Ditch
Area 4 SO
O
DD Area 10 Access Drive Swale CB1
c7
Diversi n Ditch 1 P Area 1.1 Area 0 Replaced C Ivert
CB
D1 Pond S1 < C2 Area 3 D3 D4
Dra D2 Swale Proposed Culvert S2 Draw 'ch Next to Road
/Draw CC Swale
D5
/ Draw
D6
Draw
D7 \`,,Q'. CA -n�
Outfall to Avent Creek co
� 0,,� ....EIS. r
/1L ''
rN •--
O4•OU54 •-
Cc.. .1
//('f.l\�`
(Subca) Reach 'on.
MI Routing Diagram for 20241024_Harnett County_NW CC_Construction Condition;
Prepared by HDR, Inc, Printed 10/28/2024
HydroCAD®10.00-20 s/n 11397 ©2017 HydroCAD Software Solutions LLC

20241024_Harnett County_NW CC_Construction Conditions
Prepared by HDR, Inc Printed 10/28/2024
HydroCAD® 10.00-20 s/n 11397 ©2017 HydroCAD Software Solutions LLC Page 2
Area Listing (all nodes)
Area CN Description
(acres) (subcatchment-numbers)
18.218 61 >75% Grass cover, Good, HSG B (1, 1.1, 2, 3, 4, 5)
1.645 96 Gravel surface, HSG B (1.1, 2, 3, 5)
0.150 98 Paved parking, HSG B (5)
6.511 55 Woods, Good, HSG B (1, 1.1, 2)
26.524 62 TOTAL AREA

20241024_Harnett County_NW CC_Construction Conditions
Prepared by HDR, Inc Printed 10/28/2024
HydroCAD® 10.00-20 s/n 11397 ©2017 HydroCAD Software Solutions LLC Page 3
Soil Listing (all nodes)
Area Soil Subcatchment
(acres) Group Numbers
0.000 HSG A
26.524 HSGB 1, 1.1, 2, 3, 4, 5
0.000 HSG C
0.000 HSG D
0.000 Other
26.524 TOTAL AREA

20241024_Harnett County_NW CC_Construction Conditions
Prepared by HDR, Inc Printed 10/28/2024
HydroCAD® 10.00-20 s/n 11397 ©2017 HydroCAD Software Solutions LLC Page 4
Ground Covers (all nodes)
HSG-A HSG-B HSG-C HSG-D Other Total Ground Subcatchment
(acres) (acres) (acres) (acres) (acres) (acres) Cover Numbers
0.000 18.218 0.000 0.000 0.000 18.218 >75% Grass cover, Good 1, 1.1, 2,
3, 4, 5
0.000 1.645 0.000 0.000 0.000 1.645 Gravel surface 1.1, 2, 3,
5
0.000 0.150 0.000 0.000 0.000 0.150 Paved parking 5
0.000 6.511 0.000 0.000 0.000 6.511 Woods, Good 1, 1.1, 2
0.000 26.524 0.000 0.000 0.000 26.524 TOTAL AREA

20241024_Harnett County_NW CC_Construction Conditions
Prepared by HDR, Inc Printed 10/28/2024
HydroCAD® 10.00-20 s/n 11397 ©2017 HydroCAD Software Solutions LLC Page 5
Pipe Listing (all nodes)
Line# Node In-Invert Out-Invert Length Slope n Diam/Width Height Inside-Fill
Number (feet) (feet) (feet) (ft/ft) (inches) (inches) (inches)
1 1P 318.00 317.00 66.0 0.0152 0.011 24.0 0.0 0.0
2 C 1 354.00 351.50 137.0 0.0182 0.012 30.0 0.0 0.0
3 C2 334.40 330.50 45.0 0.0867 0.012 30.0 0.0 0.0

20241024_Harnett County_NW CC_Construction CondType 1124-hr 1 y 24h Rainfall=3.05"
Prepared by HDR, Inc Printed 10/28/2024
HydroCAD® 10.00-20 s/n 11397 ©2017 HydroCAD Software Solutions LLC Page 6
Time span=0.00-180.00 hrs, dt=0.01 hrs, 18001 points
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN
Reach routing by Dyn-Stor-Ind method - Pond routing by Dyn-Stor-Ind method
Subcatchment 1: Area 1 Runoff Area=9.848 ac 0.00% Impervious Runoff Depth=0.29"
Flow Length=830' Tc=24.0 min CN=58 Runoff=1.33 cfs 0.238 af
Subcatchment 1.1: Area 1.1 Runoff Area=1.761 ac 0.00% Impervious Runoff Depth=0.35"
Flow Length=286' Tc=9.2 min CN=60 Runoff=0.65 cfs 0.052 af
Subcatchment2: Area 2 Runoff Area=5.131 ac 0.00% Impervious Runoff Depth=0.53"
Flow Length=500' Tc=11.8 min CN=65 Runoff=3.19 cfs 0.226 af
Subcatchment3: Area 3 Runoff Area=1.231 ac 0.00% Impervious Runoff Depth=0.99"
Flow Length=326' Tc=22.4 min CN=75 Runoff=1.21 cfs 0.102 af
Subcatchment4: Area 4 Runoff Area=6.257 ac 0.00% Impervious Runoff Depth=0.38"
Flow Length=606' Tc=13.1 min CN=61 Runoff=2.19 cfs 0.200 af
Subcatchment5: Area 4 Runoff Area=2.296 ac 6.53% Impervious Runoff Depth=0.61"
Flow Length=275' Tc=10.3 min CN=67 Runoff=1.87 cfs 0.117 af
Reach DO: NCDOT Road Ditch Avg. Flow Depth=0.36' Max Vel=1.99 fps Inflow=2.19 cfs 0.200 af
n=0.035 L=1,130.0' S=0.0159 '/' Capacity=210.84 cfs Outflow=1.46 cfs 0.200 af
Reach D1: Draw Avg. Flow Depth=0.11' Max Vet=0.21 fps Inflow=1.34 cfs 0.515 af
n=0.400 L=500.0' S=0.0620 '/' Capacity=252.99 cfs Outflow=0.65 cfs 0.513 af
Reach D2: Draw Avg. Flow Depth=0.00' Max Vet=0.00 fps
n=0.400 L=430.0' S=0.0977 'I Capacity=211.86 cfs Outflow=0.00 cfs 0.000 af
Reach D3: Draw Avg. Flow Depth=0.00' Max Vel=0.00 fps
n=0.400 L=228.0' S=0.1667 '/' Capacity=432.67 cfs Outflow=0.00 cfs 0.000 af
Reach D4: Ditch Next to Road Avg. Flow Depth=0.62' Max Vet=0.57 fps Inflow=2.65 cfs 0.317 af
n=0.400 L=500.0' S=0.0720 '/' Capacity=49.87 cfs Outflow=1.74 cfs 0.317 af
Reach D5: Draw Avg. Flow Depth=0.16' Max Vet=0.24 fps Inflow=0.65 cfs 0.513 af
n=0.400 L=982.0' S=0.0570 '/' Capacity=120.90 cfs Outflow=0.42 cfs 0.509 af
Reach D6: Draw Avg. Flow Depth=0.11' Max Vel=0.19 fps Inflow=1.74 cfs 0.317 af
n=0.400 L=1,720.0' S=0.0500 '/' Capacity=198.54 cfs Outflow=0.45 cfs 0.317 af
Reach D7: Outfall to Avent Creek Avg. Flow Depth=0.19' Max Vel=0.23 fps Inflow=0.87 cfs 0.826 af
n=0.400 L=130.0' S=0.0385 '/' Capacity=132.42 cfs Outflow=0.87 cfs 0.826 af
Reach DD: Diversion Ditch Avg. Flow Depth=0.05' Max Vet=1.82 fps Inflow=1.33 cfs 0.238 af
n=0.022 L=240.0' S=0.0375 'I Capacity=734.43 cfs Outflow=1.32 cfs 0.238 af
Reach SO: Access Drive Swale Avg. Flow Depth=0.24' Max Vet=1.05 fps Inflow=1.87 cfs 0.117 af
n=0.030 L=540.0' S=0.0037'/' Capacity=72.46 cfs Outflow=1.31 cfs 0.117 af

20241024_Harnett County_NW CC_Construction CondType 1124-hr 1 y 24h Rainfall=3.05"
Prepared by HDR, Inc Printed 10/28/2024
HydroCAD® 10.00-20 s/n 11397 ©2017 HydroCAD Software Solutions LLC Page 7
Reach S1: Swale Avg. Flow Depth=0.22' Max Vet=3.52 fps Inflow=4.01 cfs 0.328 af
n=0.022 L=390.0' S=0.0269 '/' Capacity=340.18 cfs Outflow=3.93 cfs 0.328 af
Reach S2: CC Swale Avg. Flow Depth=0.31' Max Vet=3.67 fps Inflow=4.13 cfs 0.328 af
n=0.022 L=455.0' S=0.0233'/' Capacity=49.84 cfs Outflow=4.01 cfs 0.328 af
Pond 1 P: Pond Peak EIev=323.80' Storage=29,966 cf Inflow=4.36 cfs 0.380 af
Primary=0.03 cfs 0.277 af Secondary=0.00 cfs 0.000 af Outflow=0.03 cfs 0.277 af
Pond C 1: Replaced Culvert Peak EIev=354.63' Inflow=2.65 cfs 0.317 af
Primary=2.65 cfs 0.317 af Secondary=0.00 cfs 0.000 af Outflow=2.65 cfs 0.317 af
Pond C2: Proposed Culvert Peak EIev=335.19' Inflow=4.01 cfs 0.328 af
30.0" Round Culvert n=0.012 L=45.0' S=0.0867 '/' Outflow=4.01 cfs 0.328 af
Total Runoff Area = 26.524 ac Runoff Volume = 0.935 af Average Runoff Depth = 0.42"
99.43% Pervious = 26.374 ac 0.57% Impervious = 0.150 ac

20241024_Harnett County_NW CC_Construction CondType 1124-hr ly 24h Rainfall=3.05"
Prepared by HDR, Inc Printed 10/28/2024
HydroCAD® 10.00-20 s/n 11397 ©2017 HydroCAD Software Solutions LLC Page 8
Summary for Subcatchment 1: Area 1
Runoff = 1.33 cfs @ 12.27 hrs, Volume= 0.238 af, Depth= 0.29"
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-180.00 hrs, dt= 0.01 hrs
Type II 24-hr 1 y 24h Rainfall=3.05"
Area (ac) CN Description
5.230 61 >75% Grass cover, Good, HSG B
4.618 55 Woods, Good, HSG B
9.848 58 Weighted Average
9.848 100.00% Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
13.3 100 0.0200 0.13 Sheet Flow,
Grass: Dense n= 0.240 P2= 3.70"
10.7 730 0.0520 1.14 Shallow Concentrated Flow,
Woodland Kv= 5.0 fps
24.0 830 Total
Subcatchment 1: Area 1
Hydrograph
0 Runoff
1.33 cfs
T (pe� II 24-h r
jly 24h IRa1nfaII=3.05"
1 - j H Runoff Arela=9.848 ac
Runoff Volume=0.238 af
13, Runoff Depth=0.29"
LL j Flow Length=830'
Tc=24.d m i n
CN=58
0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180
Time (hours)

20241024_Harnett County_NW CC_Construction CondType 1124-hr ly 24h Rainfall=3.05"
Prepared by HDR, Inc Printed 10/28/2024
HydroCAD® 10.00-20 s/n 11397 ©2017 HydroCAD Software Solutions LLC Page 9
Summary for Subcatchment 1.1: Area 1.1
Runoff = 0.65 cfs @ 12.04 hrs, Volume= 0.052 af, Depth= 0.35"
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-180.00 hrs, dt= 0.01 hrs
Type II 24-hr 1 y 24h Rainfall=3.05"
Area (ac) CN Description
1.314 61 >75% Grass cover, Good, HSG B
0.407 55 Woods, Good, HSG B
0.040 96 Gravel surface, HSG B
1.761 60 Weighted Average
1.761 100.00% Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
8.0 100 0.0700 0.21 Sheet Flow,
Grass: Dense n= 0.240 P2= 3.70"
1.2 186 0.2500 2.50 Shallow Concentrated Flow,
Woodland Kv= 5.0 fps
9.2 286 Total
Subcatchment 1.1: Area 1.1
Hydrograph
_ — — — I— t ❑Runoff
0 7E 0.65 cfs — — -
0.657v % IC�I L�F�
0.6
0.557 14 24h-kaiinfA= 0 "0.5-Y / Runoff ►re =L7611c
0.45 of o
% — — f�V �u rye .0 a2 pf
=9_3F
0 0.35-z j -Riclf! pep h
2 = / ow L-en h 86-,
05: c-7. m111
0.25-
0.2 j C VN--6O
0.15_ % 1-
0.1-
0 , . . . , . .. ..t
0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180
Time (hours)

20241024_Harnett County_NW CC_Construction CondType 1124-hr ly 24h Rainfall=3.05"
Prepared by HDR, Inc Printed 10/28/2024
HydroCAD® 10.00-20 s/n 11397 ©2017 HydroCAD Software Solutions LLC Page 10
Summary for Subcatchment 2: Area 2
Runoff = 3.19 cfs @ 12.06 hrs, Volume= 0.226 af, Depth= 0.53"
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-180.00 hrs, dt= 0.01 hrs
Type II 24-hr 1 y 24h Rainfall=3.05"
Area (ac) CN Description
2.748 61 >75% Grass cover, Good, HSG B
1.486 55 Woods, Good, HSG B
0.897 96 Gravel surface, HSG B
5.131 65 Weighted Average
5.131 100.00% Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
9.1 100 0.0200 0.18 Sheet Flow,
Grass: Short n= 0.150 P2= 3.70"
2.7 400 0.0233 2.46 Shallow Concentrated Flow,
Unpaved Kv= 16.1 fps
11.8 500 Total
Subcatchment 2: Area 2
Hydrograph
/ D Runoff
- 3.19 cfs
3y' 0-- Type-I134-hr
- j I 1y 24h Rainfall=3.05"
I Runoff Area=5.131 ac
° 2- j _Fpunoffyo1unie=0.226 of
- Runoff Depth=O.53
° / Flow Length=500'
Tc=11.8 min
0 ,/
0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180
Time (hours)

20241024_Harnett County_NW CC_Construction CondType 1124-hr ly 24h Rainfall=3.05"
Prepared by HDR, Inc Printed 10/28/2024
HydroCAD® 10.00-20 s/n 11397 ©2017 HydroCAD Software Solutions LLC Page 11
Summary for Subcatchment 3: Area 3
Runoff = 1.21 cfs @ 12.17 hrs, Volume= 0.102 af, Depth= 0.99"
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-180.00 hrs, dt= 0.01 hrs
Type II 24-hr 1 y 24h Rainfall=3.05"
Area (ac) CN Description
0.000 55 Woods, Good, HSG B
0.482 96 Gravel surface, HSG B
0.749 61 >75% Grass cover, Good, HSG B
1.231 75 Weighted Average
1.231 100.00% Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
20.0 100 0.0200 0.08 Sheet Flow,
Woods: Light underbrush n= 0.400 P2= 3.70"
2.4 226 0.0973 1.56 Shallow Concentrated Flow,
Woodland Kv= 5.0 fps
22.4 326 Total
Subcatchment 3: Area 3
Hydrograph
D Runoff
1.21 cfs
Type II 24-hr
4y 24h Rainfall-.05"
I Runoff Area=1 .231 ac
I Zunoff Volume=0.102 af
Runoff Depth=0.99"
Flow Length=326'
Tc=22.4 m i n
CAI=75
0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180
Time (hours)

20241024_Harnett County_NW CC_Construction CondType 1124-hr ly 24h Rainfall=3.05"
Prepared by HDR, Inc Printed 10/28/2024
HydroCAD® 10.00-20 s/n 11397 ©2017 HydroCAD Software Solutions LLC Page 12
Summary for Subcatchment 4: Area 4
Runoff = 2.19 cfs @ 12.09 hrs, Volume= 0.200 af, Depth= 0.38"
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-180.00 hrs, dt= 0.01 hrs
Type II 24-hr 1 y 24h Rainfall=3.05"
Area (ac) CN Description
6.257 61 >75% Grass cover, Good, HSG B
6.257 100.00% Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
9.1 100 0.0200 0.18 Sheet Flow,
Grass: Short n= 0.150 P2= 3.70"
4.0 506 0.0198 2.11 Shallow Concentrated Flow,
Grassed Waterway Kv= 15.0 fps
13.1 606 Total
Subcatchment 4: Area 4
Hydrograph
/ ❑Runoff
2.19 cfs
j T�pell4
2-- / 1y 24h Rainfall=3.05"
Runoff Area=6.257 ac
Runoff Volume=0.200 af
Runoff Depth=9.38"
LL 1 j -Plow Length 6G6
Tc=13.1 min
CN=61
0 ,/
0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180
Time (hours)

20241024_Harnett County_NW CC_Construction CondType 1124-hr ly 24h Rainfall=3.05"
Prepared by HDR, Inc Printed 10/28/2024
HydroCAD® 10.00-20 s/n 11397 ©2017 HydroCAD Software Solutions LLC Page 13
Summary for Subcatchment 5: Area 4
Runoff = 1.87 cfs @ 12.04 hrs, Volume= 0.117 af, Depth= 0.61"
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-180.00 hrs, dt= 0.01 hrs
Type II 24-hr 1 y 24h Rainfall=3.05"
Area (ac) CN Description
1.920 61 >75% Grass cover, Good, HSG B
0.226 96 Gravel surface, HSG B
0.150 98 Paved parking, HSG B
2.296 67 Weighted Average
2.146 93.47% Pervious Area
0.150 6.53% Impervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
9.1 100 0.0200 0.18 Sheet Flow,
Grass: Short n= 0.150 P2= 3.70"
1.2 175 0.0285 2.53 Shallow Concentrated Flow,
Grassed Waterway Kv= 15.0 fps
10.3 275 Total
Subcatchment 5: Area 4
Hydrograph
❑Runoff
2- 1.87 cfs
Titpe II 14-hr
1y 24h Rainfall=3.05"
Runoff Area=2.296 ac
Runoff Volume=0.1117 af
Runoff Depth J.61"
° 1 Flow Length=275'
LL
Tc=10.3 min
CN=67
III/
o iiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiii/
0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180
Time (hours)

20241024_Harnett County_NW CC_Construction CondType 1124-hr 1 y 24h Rainfall=3.05"
Prepared by HDR, Inc Printed 10/28/2024
HydroCAD® 10.00-20 s/n 11397 ©2017 HydroCAD Software Solutions LLC Page 14
Summary for Reach DO: NCDOT Road Ditch
Inflow Area = 6.257 ac, 0.00% Impervious, Inflow Depth = 0.38" for 1y 24h event
Inflow = 2.19 cfs @ 12.09 hrs, Volume= 0.200 af
Outflow = 1.46 cfs @ 12.19 hrs, Volume= 0.200 af, Atten= 33%, Lag= 6.2 min
Routing by Dyn-Stor-Ind method, Time Span= 0.00-180.00 hrs, dt= 0.01 hrs
Max. Velocity= 1.99 fps, Min. Travel Time= 9.5 min
Avg. Velocity = 0.91 fps, Avg. Travel Time= 20.6 min
Peak Storage= 830 cf @ 12.19 hrs
Average Depth at Peak Storage= 0.36'
Bank-Full Depth= 3.00' Flow Area= 30.0 sf, Capacity= 210.84 cfs
1.00' x 3.00' deep channel, n= 0.035 Earth, dense weeds
Side Slope Z-value= 3.0 '/' Top Width= 19.00'
Length= 1,130.0' Slope= 0.0159 '/'
Inlet Invert= 372.00', Outlet Invert= 354.00'
Reach DO: NCDOT Road Ditch
Hydrograph
❑Inflow
- 2.19 cfs ❑outflow)
Inflow Area=6.257 ac
2 Avg. Flow Depth=0.36'
Max Vel=1 .99 fps
1.46 cfs n=0.035
L=1 ,130.0'
S=0.0159 '/'
Capacity=210.84 cfs
•
•
j�I//%��VAVAVA fff��fff�fff��ff�fff�ff VA V
0
0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180
Time (hours)

20241024_Harnett County_NW CC_Construction CondType 1124-hr 1 y 24h Rainfall=3.05"
Prepared by HDR, Inc Printed 10/28/2024
HydroCAD® 10.00-20 s/n 11397 ©2017 HydroCAD Software Solutions LLC Page 15
Summary for Reach D1: Draw
[62] Hint: Exceeded Reach DD OUTLET depth by 0.08' @ 12.94 hrs
Inflow Area = 17.971 ac, 0.00% Impervious, Inflow Depth > 0.34" for 1y 24h event
Inflow = 1.34 cfs @ 12.30 hrs, Volume= 0.515 af
Outflow = 0.65 cfs @ 12.81 hrs, Volume= 0.513 af, Atten= 52%, Lag= 30.7 min
Routing by Dyn-Stor-Ind method, Time Span= 0.00-180.00 hrs, dt= 0.01 hrs
Max. Velocity= 0.21 fps, Min. Travel Time= 40.4 min
Avg. Velocity = 0.09 fps, Avg. Travel Time= 90.2 min
Peak Storage= 1,565 cf @ 12.81 hrs
Average Depth at Peak Storage= 0.11'
Bank-Full Depth= 3.00' Flow Area= 174.0 sf, Capacity= 252.99 cfs
28.00' x 3.00' deep channel, n= 0.400 Sheet flow: Woods+light brush
Side Slope Z-value= 10.0 '/' Top Width= 88.00'
Length= 500.0' Slope= 0.0620 '/'
Inlet Invert= 316.00', Outlet Invert= 285.00'
Reach D1: Draw
Hydrograph
❑Inflow
1.34 cfs o Outflow
Inflow Area=17.971 ac
Avg. Flow Depth=0.11'
Max Vel=0.21 fps
n=0.400
L=500.0'
LL 0.65 cfs S=0.0620 '/'
Capacity=252.99 cfs
0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180
Time (hours)

20241024_Harnett County_NW CC_Construction CondType 1124-hr 1 y 24h Rainfall=3.05"
Prepared by HDR, Inc Printed 10/28/2024
HydroCAD® 10.00-20 s/n 11397 ©2017 HydroCAD Software Solutions LLC Page 16
Summary for Reach D2: Draw
[43] Hint: Has no inflow (Outflow=Zero)
Bank-Full Depth= 3.00' Flow Area= 126.0 sf, Capacity= 211.86 cfs
12.00' x 3.00' deep channel, n= 0.400 Sheet flow: Woods+light brush
Side Slope Z-value= 10.0 '/' Top Width= 72.00'
Length= 430.0' Slope= 0.0977 '/'
Inlet Invert= 327.00', Outlet Invert= 285.00'
Reach D2: Draw
/ Hydrograph
1-
D Outflow
Avg. Flow Depth=0.00'
Max Vel=0.00 fps
n=0.400
L=430.0'
S=0.0977 '/'
Capacity=211 .86 cfs
0.00 cfs (
0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180
Time (hours)

20241024_Harnett County_NW CC_Construction CondType 1124-hr 1 y 24h Rainfall=3.05"
Prepared by HDR, Inc Printed 10/28/2024
HydroCAD® 10.00-20 s/n 11397 ©2017 HydroCAD Software Solutions LLC Page 17
Summary for Reach D3: Draw
[43] Hint: Has no inflow (Outflow=Zero)
Bank-Full Depth= 3.00' Flow Area= 195.0 sf, Capacity= 432.67 cfs
20.00' x 3.00' deep channel, n= 0.400 Sheet flow: Woods+light brush
Side Slope Z-value= 15.0 '/' Top Width= 110.00'
Length= 228.0' Slope= 0.1667 '/'
Inlet Invert= 353.00', Outlet Invert= 315.00'
Reach D3: Draw
/ Hydrograph
1-
D Outflow
Avg. Flow Depth=0.00'
Max Vel=0.00 fps
n=0.400
L=228.0'
S=0.1667 '/'
Capacity=432.67 cfs
0.00 cfs (
0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180
Time (hours)

20241024_Harnett County_NW CC_Construction CondType 1124-hr 1 y 24h Rainfall=3.05"
Prepared by HDR, Inc Printed 10/28/2024
HydroCAD® 10.00-20 s/n 11397 ©2017 HydroCAD Software Solutions LLC Page 18
Summary for Reach D4: Ditch Next to Road
Inflow Area = 8.553 ac, 1.75% Impervious, Inflow Depth = 0.44" for 1y 24h event
Inflow = 2.65 cfs @ 12.16 hrs, Volume= 0.317 of
Outflow = 1.74 cfs @ 12.35 hrs, Volume= 0.317 af, Atten= 34%, Lag= 11.8 min
Routing by Dyn-Stor-Ind method, Time Span= 0.00-180.00 hrs, dt= 0.01 hrs
Max. Velocity= 0.57 fps, Min. Travel Time= 14.5 min
Avg. Velocity = 0.21 fps, Avg. Travel Time= 40.0 min
Peak Storage= 1,516 cf @ 12.35 hrs
Average Depth at Peak Storage= 0.62'
Bank-Full Depth= 3.00' Flow Area= 36.0 sf, Capacity= 49.87 cfs
3.00' x 3.00' deep channel, n= 0.400 Sheet flow: Woods+light brush
Side Slope Z-value= 3.0 '/' Top Width= 21.00'
Length= 500.0' Slope= 0.0720 '/'
Inlet Invert= 351.00', Outlet Invert= 315.00'
Reach D4: Ditch Next to Road
Hydrograph
❑Inflow
2.65 cfs ❑outflow)
Inflow Area=8.553 ac
Avg. Flow Depth=0.62'
Max Vel=0.57 fps
21 1.74 cfs n=0.400
L=500.0'
- S=0.0720 '/'
1— Capacity=49.87 cfs
0
0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180
Time (hours)

20241024_Harnett County_NW CC_Construction CondType 1124-hr 1 y 24h Rainfall=3.05"
Prepared by HDR, Inc Printed 10/28/2024
HydroCAD® 10.00-20 s/n 11397 ©2017 HydroCAD Software Solutions LLC Page 19
Summary for Reach D5: Draw
[62] Hint: Exceeded Reach D1 OUTLET depth by 0.08' @ 14.48 hrs
[61] Hint: Exceeded Reach D2 outlet invert by 0.16' @ 13.97 hrs
Inflow Area = 17.971 ac, 0.00% Impervious, Inflow Depth > 0.34" for 1y 24h event
Inflow = 0.65 cfs @ 12.81 hrs, Volume= 0.513 af
Outflow = 0.42 cfs @ 13.97 hrs, Volume= 0.509 af, Atten= 36%, Lag= 69.6 min
Routing by Dyn-Stor-Ind method, Time Span= 0.00-180.00 hrs, dt= 0.01 hrs
Max. Velocity= 0.24 fps, Min. Travel Time= 67.8 min
Avg. Velocity = 0.09 fps, Avg. Travel Time= 174.9 min
Peak Storage= 1,693 cf @ 13.97 hrs
Average Depth at Peak Storage= 0.16'
Bank-Full Depth= 3.00' Flow Area= 93.0 sf, Capacity= 120.90 cfs
10.00' x 3.00' deep channel, n= 0.400 Sheet flow: Woods+light brush
Side Slope Z-value= 7.0 '/' Top Width= 52.00'
Length= 982.0' Slope= 0.0570 '/'
Inlet Invert= 285.00', Outlet Invert= 229.00'

20241024_Harnett County_NW CC_Construction CondType 1124-hr ly 24h Rainfall=3.05"
Prepared by HDR, Inc Printed 10/28/2024
HydroCAD® 10.00-20 s/n 11397 ©2017 HydroCAD Software Solutions LLC Page 20
Reach D5: Draw
Hydrograph
— H H I ❑Inflow
0.7 0.65 cfs A' �A 0 outflow
0.65 IIbfI lA- CQ= 11 .9 1 — C
00.6 —t + —H Aug�Fl10vu�Dpi h=b.16'
0.5 j IJVMax YeII O.24 fis
0.45 0.42 cfs I H H H A°
r I 3 0 35 A 1 _H L l— 1— 1 Z1—_
T324)1
o
0.25 z
— — + —H 129'9? S
0.1
0.05 ' /
0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180
Time (hours)

20241024_Harnett County_NW CC_Construction CondType 1124-hr 1 y 24h Rainfall=3.05"
Prepared by HDR, Inc Printed 10/28/2024
HydroCAD® 10.00-20 s/n 11397 ©2017 HydroCAD Software Solutions LLC Page 21
Summary for Reach D6: Draw
[61] Hint: Exceeded Reach D3 outlet invert by 0.11' @ 13.84 hrs
[62] Hint: Exceeded Reach D4 OUTLET depth by 0.02' @ 29.06 hrs
Inflow Area = 8.553 ac, 1.75% Impervious, Inflow Depth = 0.44" for 1y 24h event
Inflow = 1.74 cfs @ 12.35 hrs, Volume= 0.317 af
Outflow = 0.45 cfs @ 13.84 hrs, Volume= 0.317 af, Atten= 74%, Lag= 89.0 min
Routing by Dyn-Stor-Ind method, Time Span= 0.00-180.00 hrs, dt= 0.01 hrs
Max. Velocity= 0.19 fps, Min. Travel Time= 152.4 min
Avg. Velocity = 0.09 fps, Avg. Travel Time= 307.4 min
Peak Storage= 4,130 cf @ 13.84 hrs
Average Depth at Peak Storage= 0.11'
Bank-Full Depth= 3.00' Flow Area= 159.0 sf, Capacity= 198.54 cfs
20.00' x 3.00' deep channel, n= 0.400 Sheet flow: Woods+light brush
Side Slope Z-value= 11.0 '/' Top Width= 86.00'
Length= 1,720.0' Slope= 0.0500 '/'
Inlet Invert= 315.00', Outlet Invert= 229.00'

20241024_Harnett County_NW CC_Construction CondType 1124-hr ly 24h Rainfall=3.05"
Prepared by HDR, Inc Printed 10/28/2024
HydroCAD® 10.00-20 s/n 11397 ©2017 HydroCAD Software Solutions LLC Page 22
Reach D6: Draw
Hydrograph
/ 1 1 ❑Inflow
1.74 cfs 0 outflow
I nil ow Are =8.553 a c
I 1 1 Avg1. Flov' Depth=b.1 1'
I I Max VeI=0.19 fpls
1 0=0,.400
1- I I 1 ( =1,720.0'
o
A Cpci y=19".54 c s
0.45 cfs
o l l/
0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180
Time (hours)

20241024_Harnett County_NW CC_Construction CondType 1124-hr 1 y 24h Rainfall=3.05"
Prepared by HDR, Inc Printed 10/28/2024
HydroCAD® 10.00-20 s/n 11397 ©2017 HydroCAD Software Solutions LLC Page 23
Summary for Reach D7: Outfall to Avent Creek
[62] Hint: Exceeded Reach D5 OUTLET depth by 0.04' @ 15.04 hrs
[62] Hint: Exceeded Reach D6 OUTLET depth by 0.08' @ 14.15 hrs
Inflow Area = 26.524 ac, 0.57% Impervious, Inflow Depth > 0.37" for 1y 24h event
Inflow = 0.87 cfs @ 13.92 hrs, Volume= 0.826 af
Outflow = 0.87 cfs @ 14.03 hrs, Volume= 0.826 af, Atten= 0%, Lag= 6.4 min
Routing by Dyn-Stor-Ind method, Time Span= 0.00-180.00 hrs, dt= 0.01 hrs
Max. Velocity= 0.23 fps, Min. Travel Time= 9.3 min
Avg. Velocity = 0.08 fps, Avg. Travel Time= 27.1 min
Peak Storage= 484 cf @ 14.03 hrs
Average Depth at Peak Storage= 0.19'
Bank-Full Depth= 3.00' Flow Area= 117.0 sf, Capacity= 132.42 cfs
18.00' x 3.00' deep channel, n= 0.400 Sheet flow: Woods+light brush
Side Slope Z-value= 7.0 '/' Top Width= 60.00'
Length= 130.0' Slope= 0.0385 '/'
Inlet Invert= 229.00', Outlet Invert= 224.00'

20241024_Harnett County_NW CC_Construction CondType 1124-hr ly 24h Rainfall=3.05"
Prepared by HDR, Inc Printed 10/28/2024
HydroCAD® 10.00-20 s/n 11397 ©2017 HydroCAD Software Solutions LLC Page 24
Reach D7: Outfall to Avent Creek
Hydroggrraph
— ❑Inflow `
0.95=z fl R7 rfs _ _ ❑outflow)
09 0.87 cfs 1 -h t t I[#Idw Ar 2S.5 4Ic-
0.85
o 8 !j 1 —[ rt t t AVg 110W D p#i14. ' -
°o 7V j! 1 A T 1 riViax V-elI O.23 fps0.654/
Tii
0.6
0
0.5 ' 1 1 1 —L1 ” �
ay
/ E �� 19
025✓
0.2✓ z — 1— 1 1 1
0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180
Time (hours)

20241024_Harnett County_NW CC_Construction CondType 1124-hr 1 y 24h Rainfall=3.05"
Prepared by HDR, Inc Printed 10/28/2024
HydroCAD® 10.00-20 s/n 11397 ©2017 HydroCAD Software Solutions LLC Page 25
Summary for Reach DD: Diversion Ditch
Inflow Area = 9.848 ac, 0.00% Impervious, Inflow Depth = 0.29" for ly 24h event
Inflow = 1.33 cfs @ 12.27 hrs, Volume= 0.238 af
Outflow = 1.32 cfs @ 12.30 hrs, Volume= 0.238 af, Atten= 1%, Lag= 1.6 min
Routing by Dyn-Stor-Ind method, Time Span= 0.00-180.00 hrs, dt= 0.01 hrs
Max. Velocity= 1.82 fps, Min. Travel Time= 2.2 min
Avg. Velocity = 1.01 fps, Avg. Travel Time= 3.9 min
Peak Storage= 175 cf @ 12.30 hrs
Average Depth at Peak Storage= 0.05'
Bank-Full Depth= 2.00' Flow Area= 44.0 sf, Capacity= 734.43 cfs
14.00' x 2.00' deep channel, n= 0.022 Earth, clean & straight
Side Slope Z-value= 5.0 3.0 '/' Top Width= 30.00'
Length= 240.0' Slope= 0.0375 '/'
Inlet Invert= 325.00', Outlet Invert= 316.00'
7
Reach DD: Diversion Ditch
Hydrograph
/ ❑Inflow
1.33 r:fs I ❑Outflow
1.32 cfs Inflow Area=9.848 ac
Avg. Flow Depth=0.05'
j Max Vel=1 .82 fps
1-
n=0.022
L=240.0'
° S=0.0375 '/'
Capacity=734.43 cfs
0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180
Time (hours)

20241024_Harnett County_NW CC_Construction CondType 1124-hr 1 y 24h Rainfall=3.05"
Prepared by HDR, Inc Printed 10/28/2024
HydroCAD® 10.00-20 s/n 11397 ©2017 HydroCAD Software Solutions LLC Page 26
Summary for Reach SO: Access Drive Swale
Inflow Area = 2.296 ac, 6.53% Impervious, Inflow Depth = 0.61" for 1y 24h event
Inflow = 1.87 cfs @ 12.04 hrs, Volume= 0.117 of
Outflow = 1.31 cfs @ 12.12 hrs, Volume= 0.117 af, Atten= 30%, Lag= 4.7 min
Routing by Dyn-Stor-Ind method, Time Span= 0.00-180.00 hrs, dt= 0.01 hrs
Max. Velocity= 1.05 fps, Min. Travel Time= 8.5 min
Avg. Velocity = 0.34 fps, Avg. Travel Time= 26.4 min
Peak Storage= 672 cf @ 12.12 hrs
Average Depth at Peak Storage= 0.24'
Bank-Full Depth= 2.00' Flow Area= 21.0 sf, Capacity= 72.46 cfs
4.50' x 2.00' deep channel, n= 0.030 Short grass
Side Slope Z-value= 3.0 '/' Top Width= 16.50'
Length= 540.0' Slope= 0.0037 '/'
Inlet Invert= 358.00', Outlet Invert= 356.00'
Reach SO: Access Drive Swale
Hydrograph
❑Inflow
1.87 cfs ❑Outflow
2 Inflow Area=2.296 ac
Avg. Flow Depth=0.24'
Max Vet=1 .05 fps
1.31 cfs
n=0.030
L=540.0'
° S=0.0037 '/'
Capacity=72.46 cfs
0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180
Time (hours)

20241024_Harnett County_NW CC_Construction CondType 1124-hr 1 y 24h Rainfall=3.05"
Prepared by HDR, Inc Printed 10/28/2024
HydroCAD® 10.00-20 s/n 11397 ©2017 HydroCAD Software Solutions LLC Page 27
Summary for Reach S1: Swale
Inflow Area = 6.362 ac, 0.00% Impervious, Inflow Depth = 0.62" for ly 24h event
Inflow = 4.01 cfs @ 12.10 hrs, Volume= 0.328 af
Outflow = 3.93 cfs @ 12.12 hrs, Volume= 0.328 af, Atten= 2%, Lag= 1.4 min
Routing by Dyn-Stor-Ind method, Time Span= 0.00-180.00 hrs, dt= 0.01 hrs
Max. Velocity= 3.52 fps, Min. Travel Time= 1.8 min
Avg. Velocity = 1.23 fps, Avg. Travel Time= 5.3 min
Peak Storage= 435 cf @ 12.12 hrs
Average Depth at Peak Storage= 0.22'
Bank-Full Depth= 2.00' Flow Area= 28.0 sf, Capacity= 340.18 cfs
4.00' x 2.00' deep channel, n= 0.022 Earth, clean & straight
Side Slope Z-value= 5.0 '/' Top Width= 24.00'
Length= 390.0' Slope= 0.0269 '/'
Inlet Invert= 330.50', Outlet Invert= 320.00'
Reach S1: Swale
Hydrograph
❑Inflow
4.01 cfs ❑Outflow
3.93 cfs Inflow Area=6.362 ac
4 Avg. Flow Depth=0.22'
Maxl= 2 e 3 5 fps
3 n=0.022
j� L=390.0'
2 S=0.0269 '/'
Capacity=340.18 cfs
jj
0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180
Time (hours)

20241024_Harnett County_NW CC_Construction CondType 1124-hr 1 y 24h Rainfall=3.05"
Prepared by HDR, Inc Printed 10/28/2024
HydroCAD® 10.00-20 s/n 11397 ©2017 HydroCAD Software Solutions LLC Page 28
Summary for Reach S2: CC Swale
Inflow Area = 6.362 ac, 0.00% Impervious, Inflow Depth = 0.62" for ly 24h event
Inflow = 4.13 cfs @ 12.07 hrs, Volume= 0.328 af
Outflow = 4.01 cfs @ 12.10 hrs, Volume= 0.328 af, Atten= 3%, Lag= 1.6 min
Routing by Dyn-Stor-Ind method, Time Span= 0.00-180.00 hrs, dt= 0.01 hrs
Max. Velocity= 3.67 fps, Min. Travel Time= 2.1 min
Avg. Velocity = 1.33 fps, Avg. Travel Time= 5.7 min
Peak Storage= 497 cf @ 12.10 hrs
Average Depth at Peak Storage= 0.31'
Bank-Full Depth= 1.00' Flow Area= 7.0 sf, Capacity= 49.84 cfs
2.00' x 1.00' deep channel, n= 0.022 Earth, clean & straight
Side Slope Z-value= 5.0 '/' Top Width= 12.00'
Length= 455.0' Slope= 0.0233 '/'
Inlet Invert= 345.00', Outlet Invert= 334.40'
Reach S2: CC Swale
Hydrograph
❑Inflow
4.13 cfs ❑Outflow
4.01 cfs Inflow Area=6.362 ac
4 Avg. Flow Depth=0.31'
Max Vel=3.67 fps
3- n=0.022
3 _ L=455.0'
2- j S=0.0233 '/'
Capacity=49.84 cfs
1-
•
0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180
Time (hours)

20241024_Harnett County_NW CC_Construction CondType 1124-hr 1 y 24h Rainfall=3.05"
Prepared by HDR, Inc Printed 10/28/2024
HydroCAD® 10.00-20 s/n 11397 ©2017 HydroCAD Software Solutions LLC Page 29
Summary for Pond 1 P: Pond
[62] Hint: Exceeded Reach S1 OUTLET depth by 3.80' @ 24.94 hrs
Inflow Area = 8.123 ac, 0.00% Impervious, Inflow Depth = 0.56" for 1y 24h event
Inflow = 4.36 cfs @ 12.11 hrs, Volume= 0.380 af
Outflow = 0.03 cfs @ 24.57 hrs, Volume= 0.277 af, Atten= 99%, Lag= 747.7 min
Primary = 0.03 cfs @ 24.57 hrs, Volume= 0.277 af
Secondary = 0.00 cfs @ 0.00 hrs, Volume= 0.000 af
Routing by Dyn-Stor-Ind method, Time Span= 0.00-180.00 hrs, dt= 0.01 hrs
Starting Elev= 322.14' Surf.Area= 8,230 sf Storage= 14,450 cf
Peak Elev= 323.80' @ 24.57 hrs Surf.Area= 10,554 sf Storage= 29,966 cf (15,516 cf above start)
Flood Elev= 327.00' Surf.Area= 17,014 sf Storage= 73,645 cf (59,195 cf above start)
Plug-Flow detention time= (not calculated: initial storage exceeds outflow)
Center-of-Mass det. time= 4,408.1 min ( 5,314.0 - 905.9 )
Volume Invert Avail.Storage Storage Description _
#1 318.50' 73,645 cf Custom Stage Data (Prismatic)Listed below (Recalc)
Elevation Surf.Area Inc.Store Cum.Store
(feet) (sq-ft) (cubic-feet) (cubic-feet)
318.50 1,496 0 0
319.00 1,770 817 817
320.00 2,590 2,180 2,997
321.00 4,996 3,793 6,790
322.00 8,046 6,521 13,311
323.00 9,363 8,705 22,015
324.00 10,855 10,109 32,124
325.00 12,730 11,793 43,917
326.00 14,856 13,793 57,710
327.00 17,014 15,935 73,645
Device Routing Invert Outlet Devices
#1 Primary 318.00' 24.0" Round Culvert
L= 66.0' RCP, square edge headwall, Ke= 0.500
Inlet/ Outlet Invert= 318.00' / 317.00' S= 0.0152 '/' Cc= 0.900
n= 0.011 Concrete pipe, straight & clean, Flow Area= 3.14 sf
#2 Device 1 322.14' 0.5" Vert. Orifice/Grate X 3.00 C= 0.600
#3 Device 1 325.50' 48.0" x 48.0" Horiz. Orifice/Grate C= 0.600
Limited to weir flow at low heads
#4 Secondary 326.50' 25.0' long x 15.0' breadth Broad-Crested Rectangular Weir
Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60
Coef. (English) 2.68 2.70 2.70 2.64 2.63 2.64 2.64 2.63

20241024_Harnett County_NW CC_Construction CondType 1124-hr 1 y 24h Rainfall=3.05"
Prepared by HDR, Inc Printed 10/28/2024
HydroCAD® 10.00-20 s/n 11397 ©2017 HydroCAD Software Solutions LLC Page 30
Primary OutFlow Max=0.03 cfs @ 24.57 hrs HW=323.80' TW=316.04' (Dynamic Tailwater)
L =Culvert (Passes 0.03 cfs of 33.14 cfs potential flow)
2=Orifice/Grate (Orifice Controls 0.03 cfs @ 6.16 fps)
3=Orifice/Grate ( Controls 0.00 cfs)
Secondary OutFlow Max=0.00 cfs @ 0.00 hrs HW=322.14' TW=325.00' (Dynamic Tailwater)
4-4=Broad-Crested Rectangular Weir( Controls 0.00 cfs)
Pond 1 P: Pond
Hydrograph
/36cfs ❑inflow
❑Outflow
- hiflow Area=8.123 ac ose ondary
j Peak EIev=323.80'
4 Storage=29,966 cf
3
2
o
3
0
LL 2
1— I I I
4 nn' rf
0.03 cfs
0.00 cfs �
o 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180
Time (hours)

20241024_Harnett County_NW CC_Construction CondType 1124-hr 1 y 24h Rainfall=3.05"
Prepared by HDR, Inc Printed 10/28/2024
HydroCAD® 10.00-20 s/n 11397 ©2017 HydroCAD Software Solutions LLC Page 31
Summary for Pond C 1: Replaced Culvert
[62] Hint: Exceeded Reach DO OUTLET depth by 0.29' @ 12.11 hrs
Inflow Area = 8.553 ac, 1.75% Impervious, Inflow Depth = 0.44" for 1y 24h event
Inflow = 2.65 cfs @ 12.16 hrs, Volume= 0.317 of
Outflow = 2.65 cfs @ 12.16 hrs, Volume= 0.317 af, Atten= 0%, Lag= 0.0 min
Primary = 2.65 cfs @ 12.16 hrs, Volume= 0.317 af
Secondary = 0.00 cfs @ 0.00 hrs, Volume= 0.000 af
Routing by Dyn-Stor-Ind method, Time Span= 0.00-180.00 hrs, dt= 0.01 hrs
Peak Elev= 354.63' @ 12.16 hrs
Flood Elev= 357.00'
Device Routing Invert Outlet Devices
#1 Primary 354.00' 30.0" Round Culvert
L= 137.0' RCP, end-section conforming to fill, Ke= 0.500
Inlet/ Outlet Invert= 354.00' / 351.50' S= 0.0182 '/' Cc= 0.900
n= 0.012 Concrete pipe, finished, Flow Area= 4.91 sf
#2 Secondary 357.00' 50.0' long x 100.0' breadth Broad-Crested Rectangular Weir
Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60
Coef. (English) 2.68 2.70 2.70 2.64 2.63 2.64 2.64 2.63
Primary OutFlow Max=2.65 cfs @ 12.16 hrs HW=354.63' TW=351.45' (Dynamic Tailwater)
4-1=Culvert (Inlet Controls 2.65 cfs @ 2.71 fps)
Secondary OutFlow Max=0.00 cfs @ 0.00 hrs HW=354.00' TW=351.00' (Dynamic Tailwater)
4-2=Broad-Crested Rectangular Weir( Controls 0.00 cfs)

20241024_Harnett County_NW CC_Construction CondType 1124-hr 1 y 24h Rainfall=3.05"
Prepared by HDR, Inc Printed 10/28/2024
HydroCAD® 10.00-20 s/n 11397 ©2017 HydroCAD Software Solutions LLC Page 32
Pond C 1: Replaced Culvert
Hydrograph
7 Aq rf� ❑Inflow
9 Rai rf E Outflow
2.65 cfs Inflow Area=8.553 ac o Primary
e Secondary
Peak Elev=354.63'
2 -
i
1
o
1
A
0.00 cfs ; /��/����/����/����/��
0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180
Time (hours)

20241024_Harnett County_NW CC_Construction CondType 1124-hr 1 y 24h Rainfall=3.05"
Prepared by HDR, Inc Printed 10/28/2024
HydroCAD® 10.00-20 s/n 11397 ©2017 HydroCAD Software Solutions LLC Page 33
Summary for Pond C2: Proposed Culvert
[62] Hint: Exceeded Reach S2 OUTLET depth by 0.48' @ 12.10 hrs
Inflow Area = 6.362 ac, 0.00% Impervious, Inflow Depth = 0.62" for 1y 24h event
Inflow = 4.01 cfs @ 12.10 hrs, Volume= 0.328 af
Outflow = 4.01 cfs @ 12.10 hrs, Volume= 0.328 af, Atten= 0%, Lag= 0.0 min
Primary = 4.01 cfs @ 12.10 hrs, Volume= 0.328 af
Routing by Dyn-Stor-Ind method, Time Span= 0.00-180.00 hrs, dt= 0.01 hrs
Peak Elev= 335.19' @ 12.10 hrs
Flood Elev= 337.00'
Device Routing Invert Outlet Devices
#1 Primary 334.40' 30.0" Round Culvert
L= 45.0' RCP, end-section conforming to fill, Ke= 0.500
Inlet/Outlet Invert= 334.40' / 330.50' S= 0.0867 '/' Cc= 0.900
n= 0.012 Concrete pipe, finished, Flow Area= 4.91 sf
Primary OutFlow Max=4.01 cfs @ 12.10 hrs HW=335.19' TW=330.72' (Dynamic Tailwater)
4-1=Culvert (Inlet Controls 4.01 cfs @ 3.02 fps)
Pond C2: Proposed Culvert
Hydrograph
n1 rf ❑Inflow
❑Primary
4.01 cfs 4-
Inflow Area=6.362 ac
Peak Elev=335.19'
30.0"
3
_ /
Round Culvert
3 _ n=0.012
2 , L=45.0'
_ S=0.0867 '/'
1-
It
0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180
Time (hours)

20241024_Harnett County_NW CC_Construction Con Type II 24-hr 25y 24h Rainfall=6.75"
Prepared by HDR, Inc Printed 10/28/2024
HydroCAD® 10.00-20 s/n 11397 ©2017 HydroCAD Software Solutions LLC Page 34
Time span=0.00-180.00 hrs, dt=0.01 hrs, 18001 points
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN
Reach routing by Dyn-Stor-Ind method - Pond routing by Dyn-Stor-Ind method
Subcatchment 1: Area 1 Runoff Area=9.848 ac 0.00% Impervious Runoff Depth=2.24"
Flow Length=830' Tc=24.0 min CN=58 Runoff=20.88 cfs 1.839 af
Subcatchment 1.1: Area 1.1 Runoff Area=1.761 ac 0.00% Impervious Runoff Depth=2.43"
Flow Length=286' Tc=9.2 min CN=60 Runoff=6.73 cfs 0.356 af
Subcatchment2: Area 2 Runoff Area=5.131 ac 0.00% Impervious Runoff Depth=2.91"
Flow Length=500' Tc=11.8 min CN=65 Runoff=21.52 cfs 1.244 af
Subcatchment3: Area 3 Runoff Area=1.231 ac 0.00% Impervious Runoff Depth=3.93"
Flow Length=326' Tc=22.4 min CN=75 Runoff=5.04 cfs 0.403 af
Subcatchment4: Area 4 Runoff Area=6.257 ac 0.00% Impervious Runoff Depth=2.52"
Flow Length=606' Tc=13.1 min CN=61 Runoff=21.47 cfs 1.316 af
Subcatchment5: Area 4 Runoff Area=2.296 ac 6.53% Impervious Runoff Depth=3.11"
Flow Length=275' Tc=10.3 min CN=67 Runoff=10.89 cfs 0.595 af
Reach DO: NCDOT Road Ditch Avg. Flow Depth=1.13' Max Vel=3.84 fps Inflow=21.47 cfs 1.316 af
n=0.035 L=1,130.0' S=0.0159 '/' Capacity=210.84 cfs Outflow=18.97 cfs 1.316 af
Reach D1: Draw Avg. Flow Depth=0.77' Max Vel=0.68 fps Inflow=21.27 cfs 3.419 af
n=0.400 L=500.0' S=0.0620 '/' Capacity=252.99 cfs Outflow=18.65 cfs 3.416 af
Reach D2: Draw Avg. Flow Depth=0.00' Max Vet=0.00 fps
n=0.400 L=430.0' S=0.0977 'I Capacity=211.86 cfs Outflow=0.00 cfs 0.000 af
Reach D3: Draw Avg. Flow Depth=0.00' Max Vel=0.00 fps
n=0.400 L=228.0' S=0.1667 'I Capacity=432.67 cfs Outflow=0.00 cfs 0.000 af
Reach D4: Ditch Next to Road Avg. Flow Depth=2.15' Max Vel=1.14 fps Inflow=28.18 cfs 1.910 af
n=0.400 L=500.0' S=0.0720 '/' Capacity=49.87 cfs Outflow=23.15 cfs 1.910 af
Reach D5: Draw Avg. Flow Depth=1.07' Max Vel=0.73 fps Inflow=18.65 cfs 3.416 af
n=0.400 L=982.0' S=0.0570 '/' Capacity=120.90 cfs Outflow=13.62 cfs 3.409 af
Reach D6: Draw Avg. Flow Depth=0.58' Max Vet=0.50 fps Inflow=23.15 cfs 1.910 af
n=0.400 L=1,720.0' S=0.0500 '/' Capacity=198.54 cfs Outflow=7.76 cfs 1.910 af
Reach D7: Outfall to Avent Creek Avg. Flow Depth=1.18' Max Vel=0.68 fps Inflow=21.17 cfs 5.319 af
n=0.400 L=130.0' S=0.0385 '/' Capacity=132.42 cfs Outflow=21.09 cfs 5.318 af
Reach DD: Diversion Ditch Avg. Flow Depth=0.27' Max Vet=5.17 fps Inflow=20.88 cfs 1.839 af
n=0.022 L=240.0' S=0.0375 '/' Capacity=734.43 cfs Outflow=20.83 cfs 1.839 af
Reach SO: Access Drive Swale Avg. Flow Depth=0.73' Max Vel=1.99 fps Inflow=10.89 cfs 0.595 af
n=0.030 L=540.0' S=0.0037'/' Capacity=72.46 cfs Outflow=9.71 cfs 0.595 af

20241024_Harnett County_NW CC_Construction Con Type II 24-hr 25y 24h Rainfall=6.75"
Prepared by HDR, Inc Printed 10/28/2024
HydroCAD® 10.00-20 s/n 11397 ©2017 HydroCAD Software Solutions LLC Page 35
Reach S1: Swale Avg. Flow Depth=0.59' Max Vel=6.11 fps Inflow=25.18 cfs 1.648 af
n=0.022 L=390.0' S=0.0269 '/' Capacity=340.18 cfs Outflow=25.00 cfs 1.648 af
Reach S2: CC Swale Avg. Flow Depth=0.74' Max Vel=5.98 fps Inflow=25.47 cfs 1.648 af
n=0.022 L=455.0' S=0.0233 '/' Capacity=49.84 cfs Outflow=25.18 cfs 1.648 af
Pond 1 P: Pond Peak Elev=325.76' Storage=54,258 cf Inflow=30.53 cfs 2.004 af
Primary=7.12 cfs 1.580 af Secondary=0.00 cfs 0.000 af Outflow=7.12 cfs 1.580 af
Pond C 1: Replaced Culvert Peak Elev=356.67' Inflow=28.18 cfs 1.910 af
Primary=28.18 cfs 1.910 af Secondary=0.00 cfs 0.000 af Outflow=28.18 cfs 1.910 af
Pond C2: Proposed Culvert Peak Elev=336.77' Inflow=25.18 cfs 1.648 af
30.0" Round Culvert n=0.012 L=45.0' S=0.0867 '/' Outflow=25.18 cfs 1.648 af
Total Runoff Area = 26.524 ac Runoff Volume = 5.753 af Average Runoff Depth = 2.60"
99.43% Pervious = 26.374 ac 0.57% Impervious = 0.150 ac

20241024_Harnett County_NW CC_Construction Con Type 1124-hr 25y 24h Rainfall=6.75"
Prepared by HDR, Inc Printed 10/28/2024
HydroCAD® 10.00-20 s/n 11397 ©2017 HydroCAD Software Solutions LLC Page 36
Summary for Subcatchment 1: Area 1
Runoff = 20.88 cfs @ 12.19 hrs, Volume= 1.839 af, Depth= 2.24"
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-180.00 hrs, dt= 0.01 hrs
Type II 24-hr 25y 24h Rainfall=6.75"
Area (ac) CN Description
5.230 61 >75% Grass cover, Good, HSG B
4.618 55 Woods, Good, HSG B
9.848 58 Weighted Average
9.848 100.00% Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
13.3 100 0.0200 0.13 Sheet Flow,
Grass: Dense n= 0.240 P2= 3.70"
10.7 730 0.0520 1.14 Shallow Concentrated Flow,
Woodland Kv= 5.0 fps
24.0 830 Total
Subcatchment 1: Area 1
Hydrograph
23 ■Runoff
22. 20.88 cfs
2 0 T�yp� i iE a. r
18/
17 ilunbffiAria 19.848 c
15
14V % 11 unlog Vflume 8. 9 of
12V_ F�no -fep "
Li10V —Plow Len th=830'
— 1�c 4 min —_
6 % H CiV---6-B
24/-17
— -
0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180
Time (hours)

20241024_Harnett County_NW CC_Construction Con Type 1124-hr 25y 24h Rainfall=6.75"
Prepared by HDR, Inc Printed 10/28/2024
HydroCAD® 10.00-20 s/n 11397 ©2017 HydroCAD Software Solutions LLC Page 37
Summary for Subcatchment 1.1: Area 1.1
Runoff = 6.73 cfs @ 12.01 hrs, Volume= 0.356 af, Depth= 2.43"
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-180.00 hrs, dt= 0.01 hrs
Type II 24-hr 25y 24h Rainfall=6.75"
Area (ac) CN Description
1.314 61 >75% Grass cover, Good, HSG B
0.407 55 Woods, Good, HSG B
0.040 96 Gravel surface, HSG B
1.761 60 Weighted Average
1.761 100.00% Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
8.0 100 0.0700 0.21 Sheet Flow,
Grass: Dense n= 0.240 P2= 3.70"
1.2 186 0.2500 2.50 Shallow Concentrated Flow,
Woodland Kv= 5.0 fps
9.2 286 Total
Subcatchment 1.1: Area 1.1
Hydrograph
❑Runoff
7- 6.73 cfs
e Type II 14-hr
61/ j 25y 24h Rainfall=6.75"
% —I Run-bff Area=1 .761 ac
/ F�uI1off Vo,Iume=0.356 oaf
Runoff Depth=2.43"
= % _Plow Length=286'
3
i-c=9.2 m i n
2 C14=6O
1
0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180
Time (hours)

20241024_Harnett County_NW CC_Construction Con Type 1124-hr 25y 24h Rainfall=6.75"
Prepared by HDR, Inc Printed 10/28/2024
HydroCAD® 10.00-20 s/n 11397 ©2017 HydroCAD Software Solutions LLC Page 38
Summary for Subcatchment 2: Area 2
Runoff = 21.52 cfs @ 12.04 hrs, Volume= 1.244 af, Depth= 2.91"
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-180.00 hrs, dt= 0.01 hrs
Type II 24-hr 25y 24h Rainfall=6.75"
Area (ac) CN Description
2.748 61 >75% Grass cover, Good, HSG B
1.486 55 Woods, Good, HSG B
0.897 96 Gravel surface, HSG B
5.131 65 Weighted Average
5.131 100.00% Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
9.1 100 0.0200 0.18 Sheet Flow,
Grass: Short n= 0.150 P2= 3.70"
2.7 400 0.0233 2.46 Shallow Concentrated Flow,
Unpaved Kv= 16.1 fps
11.8 500 Total
Subcatchment 2: Area 2
Hydrograph
241/1 — — —1 — — — •Runoff
23 21.5e-fsi
22_ / — —
21
20_'
19_ 2y4h Rnfl=�.7 "
18-
17= — — — —I -Run-off-Area=5.1-31 c -
;4= i i _ upo#1 V lu e 1.2144 f =
12= i Rer4-h2.91"
0 1101V, / I Length=500'
Li owLe 500
$4/ i c=i1$ min
7 r eiV=65
4 0 rt
2 o � J
0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180
Time (hours)

20241024_Harnett County_NW CC_Construction Con Type 1124-hr 25y 24h Rainfall=6.75"
Prepared by HDR, Inc Printed 10/28/2024
HydroCAD® 10.00-20 s/n 11397 ©2017 HydroCAD Software Solutions LLC Page 39
Summary for Subcatchment 3: Area 3
Runoff = 5.04 cfs @ 12.15 hrs, Volume= 0.403 af, Depth= 3.93"
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-180.00 hrs, dt= 0.01 hrs
Type II 24-hr 25y 24h Rainfall=6.75"
Area (ac) CN Description
0.000 55 Woods, Good, HSG B
0.482 96 Gravel surface, HSG B
0.749 61 >75% Grass cover, Good, HSG B
1.231 75 Weighted Average
1.231 100.00% Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
20.0 100 0.0200 0.08 Sheet Flow,
Woods: Light underbrush n= 0.400 P2= 3.70"
2.4 226 0.0973 1.56 Shallow Concentrated Flow,
Woodland Kv= 5.0 fps
22.4 326 Total
Subcatchment 3: Area 3
Hydrograph
0 Runoff
5.04 cfs
5 Type II 24-hr
1 2y 24h Rainfall=6.75"
4 j Runoff Arela=1.231 do
F�uI1off Vo,Iume70.403 oaf
3� % Rulnoff Depth=3.93"
_ Flow Length=326'
2- Tic==12.4 mein
CN='5
0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180
Time (hours)

20241024_Harnett County_NW CC_Construction Con Type 1124-hr 25y 24h Rainfall=6.75"
Prepared by HDR, Inc Printed 10/28/2024
HydroCAD® 10.00-20 s/n 11397 ©2017 HydroCAD Software Solutions LLC Page 40
Summary for Subcatchment 4: Area 4
Runoff = 21.47 cfs @ 12.06 hrs, Volume= 1.316 af, Depth= 2.52"
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-180.00 hrs, dt= 0.01 hrs
Type II 24-hr 25y 24h Rainfall=6.75"
Area (ac) CN Description
6.257 61 >75% Grass cover, Good, HSG B
6.257 100.00% Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
9.1 100 0.0200 0.18 Sheet Flow,
Grass: Short n= 0.150 P2= 3.70"
4.0 506 0.0198 2.11 Shallow Concentrated Flow,
Grassed Waterway Kv= 15.0 fps
13.1 606 Total
Subcatchment 4: Area 4
Hydrograph
24 - •Runoff
23- 21.47 cfs _
22211 % —
— H
114 r
20_
19_% - 2y4h Ranfill4.7 " -
— — —
17_ -Run-off-Ar4a=6.257
15=� off Vol ui a 1 -
1 ='
w4=
13_ not Beph '5?n,
312 lowh-
666
0 1110
1
LL '9� L—e t
ic3. mnm
7=-
4
3
2 I
0
0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180
Time (hours)

20241024_Harnett County_NW CC_Construction Con Type 1124-hr 25y 24h Rainfall=6.75"
Prepared by HDR, Inc Printed 10/28/2024
HydroCAD® 10.00-20 s/n 11397 ©2017 HydroCAD Software Solutions LLC Page 41
Summary for Subcatchment 5: Area 4
Runoff = 10.89 cfs @ 12.02 hrs, Volume= 0.595 af, Depth= 3.11"
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-180.00 hrs, dt= 0.01 hrs
Type II 24-hr 25y 24h Rainfall=6.75"
Area (ac) CN Description
1.920 61 >75% Grass cover, Good, HSG B
0.226 96 Gravel surface, HSG B
0.150 98 Paved parking, HSG B
2.296 67 Weighted Average
2.146 93.47% Pervious Area
0.150 6.53% Impervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
9.1 100 0.0200 0.18 Sheet Flow,
Grass: Short n= 0.150 P2= 3.70"
1.2 175 0.0285 2.53 Shallow Concentrated Flow,
Grassed Waterway Kv= 15.0 fps
10.3 275 Total
Subcatchment 5: Area 4
Hydrograph
12
■Runoff
10.89 cfs
11 pi 11_ 4 r -
y-24hiRai nfal l= .75"
I -Runoff-Area=2.2-96 ac -
$_ j -u+noff V-gIuie=0.5 5-af -
w pepth= .11"
6_ ;
o
low Length=27-5'
/
41/- i�c=10.3 min -
C-V==7 —
3
2_/
0
0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180
Time (hours)

20241024_Harnett County_NW CC_Construction Con Type 1124-hr 25y 24h Rainfall=6.75"
Prepared by HDR, Inc Printed 10/28/2024
HydroCAD® 10.00-20 s/n 11397 ©2017 HydroCAD Software Solutions LLC Page 42
Summary for Reach DO: NCDOT Road Ditch
Inflow Area = 6.257 ac, 0.00% Impervious, Inflow Depth = 2.52" for 25y 24h event
Inflow = 21.47 cfs @ 12.06 hrs, Volume= 1.316 af
Outflow = 18.97 cfs @ 12.11 hrs, Volume= 1.316 af, Atten= 12%, Lag= 3.2 min
Routing by Dyn-Stor-Ind method, Time Span= 0.00-180.00 hrs, dt= 0.01 hrs
Max. Velocity= 3.84 fps, Min. Travel Time= 4.9 min
Avg. Velocity = 1.34 fps, Avg. Travel Time= 14.1 min
Peak Storage= 5,577 cf @ 12.11 hrs
Average Depth at Peak Storage= 1.13'
Bank-Full Depth= 3.00' Flow Area= 30.0 sf, Capacity= 210.84 cfs
1.00' x 3.00' deep channel, n= 0.035 Earth, dense weeds
Side Slope Z-value= 3.0 '/' Top Width= 19.00'
Length= 1,130.0' Slope= 0.0159 '/'
Inlet Invert= 372.00', Outlet Invert= 354.00'
Reach DO: NCDOT Road Ditch
Hydrograph
I I I
rl Inflow
241121.47 cfs 1 — — ❑outflow
22H — n 131 Are 6.2-67 ac
20 18.97 cfs —I 4 4 Avc Fio Dipth=�l:9!3'
19_ I /
18= I I —I I I RbxA/463A34.
1716
15= , —I I 11=9'05—
w 14- I / 1 i1
13
12 / I P_ 1
_ ,1,
a 11= IH V p.�1
_ /% I �p�ci =�a l 4 c
a %/ — — I t - t — —
3=
0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180
Time (hours)

20241024_Harnett County_NW CC_Construction Con Type 1124-hr 25y 24h Rainfall=6.75"
Prepared by HDR, Inc Printed 10/28/2024
HydroCAD® 10.00-20 s/n 11397 ©2017 HydroCAD Software Solutions LLC Page 43
Summary for Reach D1: Draw
[62] Hint: Exceeded Reach DD OUTLET depth by 0.59' © 12.49 hrs
Inflow Area = 17.971 ac, 0.00% Impervious, Inflow Depth > 2.28" for 25y 24h event
Inflow = 21.27 cfs @ 12.32 hrs, Volume= 3.419 of
Outflow = 18.65 cfs @ 12.43 hrs, Volume= 3.416 af, Atten= 12%, Lag= 6.4 min
Routing by Dyn-Stor-Ind method, Time Span= 0.00-180.00 hrs, dt= 0.01 hrs
Max. Velocity= 0.68 fps, Min. Travel Time= 12.2 min
Avg. Velocity = 0.11 fps, Avg. Travel Time= 78.2 min
Peak Storage= 13,700 cf @ 12.43 hrs
Average Depth at Peak Storage= 0.77'
Bank-Full Depth= 3.00' Flow Area= 174.0 sf, Capacity= 252.99 cfs
28.00' x 3.00' deep channel, n= 0.400 Sheet flow: Woods+light brush
Side Slope Z-value= 10.0 '/' Top Width= 88.00'
Length= 500.0' Slope= 0.0620 '/'
Inlet Invert= 316.00', Outlet Invert= 285.00'
7%.*%.%*%%%-%%*%%%%%%%* ***•••..
Reach D1: Draw
Hydrograph
H
■Inflow
23lz 21.27 cfs ■outflow
22 I 11i�nflwLAre�a147� 7�'I a`�
21=
20- 18.65 cfs 4 Av Fio th=V./ 17'
19
;; x1/4 OX8 Ts
16 15t H 0I
H n11— .400—
a 1413
' I %%
11
P"ci!"Y=12 ?' ?-' s7
0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180
Time (hours)

20241024_Harnett County_NW CC_Construction Con Type II 24-hr 25y 24h Rainfall=6.75"
Prepared by HDR, Inc Printed 10/28/2024
HydroCAD® 10.00-20 s/n 11397 ©2017 HydroCAD Software Solutions LLC Page 44
Summary for Reach D2: Draw
[43] Hint: Has no inflow (Outflow=Zero)
Bank-Full Depth= 3.00' Flow Area= 126.0 sf, Capacity= 211.86 cfs
12.00' x 3.00' deep channel, n= 0.400 Sheet flow: Woods+light brush
Side Slope Z-value= 10.0 '/' Top Width= 72.00'
Length= 430.0' Slope= 0.0977 '/'
Inlet Invert= 327.00', Outlet Invert= 285.00'
Reach D2: Draw
/ Hydrograph
1-
D Outflow
Avg. Flow Depth=0.00'
Max Vel=0.00 fps
n=0.400
L=430.0'
S=0.0977 '/'
Capacity=211 .86 cfs
0.00 cfs (
0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180
Time (hours)

20241024_Harnett County_NW CC_Construction Con Type II 24-hr 25y 24h Rainfall=6.75"
Prepared by HDR, Inc Printed 10/28/2024
HydroCAD® 10.00-20 s/n 11397 ©2017 HydroCAD Software Solutions LLC Page 45
Summary for Reach D3: Draw
[43] Hint: Has no inflow (Outflow=Zero)
Bank-Full Depth= 3.00' Flow Area= 195.0 sf, Capacity= 432.67 cfs
20.00' x 3.00' deep channel, n= 0.400 Sheet flow: Woods+light brush
Side Slope Z-value= 15.0 '/' Top Width= 110.00'
Length= 228.0' Slope= 0.1667 '/'
Inlet Invert= 353.00', Outlet Invert= 315.00'
Reach D3: Draw
/ Hydrograph
1-
D Outflow
Avg. Flow Depth=0.00'
Max Vel=0.00 fps
n=0.400
L=228.0'
S=0.1667 '/'
Capacity=432.67 cfs
0.00 cfs (
0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180
Time (hours)

20241024_Harnett County_NW CC_Construction Con Type 1124-hr 25y 24h Rainfall=6.75"
Prepared by HDR, Inc Printed 10/28/2024
HydroCAD® 10.00-20 s/n 11397 ©2017 HydroCAD Software Solutions LLC Page 46
Summary for Reach D4: Ditch Next to Road
Inflow Area = 8.553 ac, 1.75% Impervious, Inflow Depth = 2.68" for 25y 24h event
Inflow = 28.18 cfs @ 12.09 hrs, Volume= 1.910 of
Outflow = 23.15 cfs @ 12.17 hrs, Volume= 1.910 af, Atten= 18%, Lag= 4.8 min
Routing by Dyn-Stor-Ind method, Time Span= 0.00-180.00 hrs, dt= 0.01 hrs
Max. Velocity= 1.14 fps, Min. Travel Time= 7.3 min
Avg. Velocity = 0.30 fps, Avg. Travel Time= 28.2 min
Peak Storage= 10,151 cf @ 12.17 hrs
Average Depth at Peak Storage= 2.15'
Bank-Full Depth= 3.00' Flow Area= 36.0 sf, Capacity= 49.87 cfs
3.00' x 3.00' deep channel, n= 0.400 Sheet flow: Woods+light brush
Side Slope Z-value= 3.0 '/' Top Width= 21.00'
Length= 500.0' Slope= 0.0720 '/'
Inlet Invert= 351.00', Outlet Invert= 315.00'
Reach D4: Ditch Next to Road
Hydrograph
_I _L Inflow
30 28.18 cfs f ❑outflow
28
4 n4Iol Ar-e =8.-5 3--a c-
_
26 — — H -� Avd
24� 23.15 cfs
22Lax V =1 pl�
20= 0 _I 1 1 r T rn Q.4g0
18,
16
LLo
14= ØØ =000
'/12
a ' y=4g.817-cfs-
t -
2= %�,�I//
0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180
Time (hours)

20241024_Harnett County_NW CC_Construction Con Type II 24-hr 25y 24h Rainfall=6.75"
Prepared by HDR, Inc Printed 10/28/2024
HydroCAD® 10.00-20 s/n 11397 ©2017 HydroCAD Software Solutions LLC Page 47
Summary for Reach D5: Draw
[62] Hint: Exceeded Reach D1 OUTLET depth by 0.49' @ 12.96 hrs
[61] Hint: Exceeded Reach D2 outlet invert by 1.07' @ 12.71 hrs
Inflow Area = 17.971 ac, 0.00% Impervious, Inflow Depth > 2.28" for 25y 24h event
Inflow = 18.65 cfs @ 12.43 hrs, Volume= 3.416 af
Outflow = 13.62 cfs @ 12.71 hrs, Volume= 3.409 af, Atten= 27%, Lag= 17.1 min
Routing by Dyn-Stor-Ind method, Time Span= 0.00-180.00 hrs, dt= 0.01 hrs
Max. Velocity= 0.73 fps, Min. Travel Time= 22.5 min
Avg. Velocity = 0.12 fps, Avg. Travel Time= 135.7 min
Peak Storage= 18,360 cf @ 12.71 hrs
Average Depth at Peak Storage= 1.07'
Bank-Full Depth= 3.00' Flow Area= 93.0 sf, Capacity= 120.90 cfs
10.00' x 3.00' deep channel, n= 0.400 Sheet flow: Woods+light brush
Side Slope Z-value= 7.0 '/' Top Width= 52.00'
Length= 982.0' Slope= 0.0570 '/'
Inlet Invert= 285.00', Outlet Invert= 229.00'

20241024_Harnett County_NW CC_Construction Con Type 1124-hr 25y 24h Rainfall=6.75"
Prepared by HDR, Inc Printed 10/28/2024
HydroCAD® 10.00-20 s/n 11397 ©2017 HydroCAD Software Solutions LLC Page 48
Reach D5: Draw
Hydrograph
+ - 0 Inflow
� 18.65 cfs 1 _❑outflow
20i9 — lnfl w4r 371 °c_
1s
18= /'�V FkovO*t&lA y r
16/ I -r T Mx f ei OI73If s 15i 13.62 cfs
4 13 -/ ��/% 1— — 1 1 —1 — — -L H H H H Il -O.4OOI
11 - — — — - 44 - I— 1-1 $2.Q—
° 1 I j -0 CE57 11—
$V I �pci =fit cfs
Lt I j t _L H H H H — 1— 1 - 1
0 _. (._. ��
0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180
Time (hours)

20241024_Harnett County_NW CC_Construction Con Type II 24-hr 25y 24h Rainfall=6.75"
Prepared by HDR, Inc Printed 10/28/2024
HydroCAD® 10.00-20 s/n 11397 ©2017 HydroCAD Software Solutions LLC Page 49
Summary for Reach D6: Draw
[61] Hint: Exceeded Reach D3 outlet invert by 0.58' @ 12.57 hrs
[62] Hint: Exceeded Reach D4 OUTLET depth by 0.03' @ 27.59 hrs
Inflow Area = 8.553 ac, 1.75% Impervious, Inflow Depth = 2.68" for 25y 24h event
Inflow = 23.15 cfs @ 12.17 hrs, Volume= 1.910 of
Outflow = 7.76 cfs @ 12.57 hrs, Volume= 1.910 af, Atten= 66%, Lag= 23.7 min
Routing by Dyn-Stor-Ind method, Time Span= 0.00-180.00 hrs, dt= 0.01 hrs
Max. Velocity= 0.50 fps, Min. Travel Time= 57.1 min
Avg. Velocity = 0.12 fps, Avg. Travel Time= 244.8 min
Peak Storage= 26,581 cf @ 12.57 hrs
Average Depth at Peak Storage= 0.58'
Bank-Full Depth= 3.00' Flow Area= 159.0 sf, Capacity= 198.54 cfs
20.00' x 3.00' deep channel, n= 0.400 Sheet flow: Woods+light brush
Side Slope Z-value= 11.0 '/' Top Width= 86.00'
Length= 1,720.0' Slope= 0.0500 '/'
Inlet Invert= 315.00', Outlet Invert= 229.00'

20241024_Harnett County_NW CC_Construction Con Type 1124-hr 25y 24h Rainfall=6.75"
Prepared by HDR, Inc Printed 10/28/2024
HydroCAD® 10.00-20 s/n 11397 ©2017 HydroCAD Software Solutions LLC Page 50
Reach D6: Draw
Hydrograph
I
0 Inflow
24� 23.15 cfs 0 Outflow
l
-InftoAlre =8 s58--alc--
20 , —t kv6 Ftov�D6pt1�--b5i3T-
18:/ 1 1 1 1 I Maxl VeI=0.5O fills
16" - 1 -1 4 4 I- 11=9.400-
314� j 1 1 -1 17 T I- r1 ?G.
10 — I I A A A L i_ 'c'ta351°►ciV'
7.76 cfs —1 CapaaCiy=19,.54 C!s
8 - I
6L. ,
1 1 1 1 1 1 1 1 1 1
4�
0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180
Time (hours)

20241024_Harnett County_NW CC_Construction Con Type II 24-hr 25y 24h Rainfall=6.75"
Prepared by HDR, Inc Printed 10/28/2024
HydroCAD® 10.00-20 s/n 11397 ©2017 HydroCAD Software Solutions LLC Page 51
Summary for Reach D7: Outfall to Avent Creek
[62] Hint: Exceeded Reach D5 OUTLET depth by 0.12' @ 12.96 hrs
[62] Hint: Exceeded Reach D6 OUTLET depth by 0.62' @ 12.78 hrs
Inflow Area = 26.524 ac, 0.57% Impervious, Inflow Depth > 2.41" for 25y 24h event
Inflow = 21.17 cfs @ 12.68 hrs, Volume= 5.319 of
Outflow = 21.09 cfs @ 12.72 hrs, Volume= 5.318 af, Atten= 0%, Lag= 2.4 min
Routing by Dyn-Stor-Ind method, Time Span= 0.00-180.00 hrs, dt= 0.01 hrs
Max. Velocity= 0.68 fps, Min. Travel Time= 3.2 min
Avg. Velocity = 0.10 fps, Avg. Travel Time= 22.3 min
Peak Storage= 4,048 cf @ 12.72 hrs
Average Depth at Peak Storage= 1.18'
Bank-Full Depth= 3.00' Flow Area= 117.0 sf, Capacity= 132.42 cfs
18.00' x 3.00' deep channel, n= 0.400 Sheet flow: Woods+light brush
Side Slope Z-value= 7.0 '/' Top Width= 60.00'
Length= 130.0' Slope= 0.0385 '/'
Inlet Invert= 229.00', Outlet Invert= 224.00'

20241024_Harnett County_NW CC_Construction Con Type 1124-hr 25y 24h Rainfall=6.75"
Prepared by HDR, Inc Printed 10/28/2024
HydroCAD® 10.00-20 s/n 11397 ©2017 HydroCAD Software Solutions LLC Page 52
Reach D7: Outfall to Avent Creek
Hydrograph
1 I —1 ± T
4117r Outflow
h
2221_ 21.09 cfs ❑Inflow 1 1 1 — 1�iifIiW kr =261-i4 . C-
1204 9 I % — 1 1 —I H 4 4 kv Fkov ►dDJ tI CIA ill'
17 1 1 1 Nf x1A/ dX8Tpls-
161
15 % — 1 1 H H H- + H- H H — fl=OI.400-
° 11.1 0. I % 0 1
11
94
81 — — 1 —1 —1 —1 4 4 9Pci =1-3?-4?-,-
64
3
2✓ ' %/ i //
0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180
Time (hours)

20241024_Harnett County_NW CC_Construction Con Type 1124-hr 25y 24h Rainfall=6.75"
Prepared by HDR, Inc Printed 10/28/2024
HydroCAD® 10.00-20 s/n 11397 ©2017 HydroCAD Software Solutions LLC Page 53
Summary for Reach DD: Diversion Ditch
Inflow Area = 9.848 ac, 0.00% Impervious, Inflow Depth = 2.24" for 25y 24h event
Inflow = 20.88 cfs @ 12.19 hrs, Volume= 1.839 of
Outflow = 20.83 cfs @ 12.20 hrs, Volume= 1.839 af, Atten= 0%, Lag= 0.4 min
Routing by Dyn-Stor-Ind method, Time Span= 0.00-180.00 hrs, dt= 0.01 hrs
Max. Velocity= 5.17 fps, Min. Travel Time= 0.8 min
Avg. Velocity = 1.64 fps, Avg. Travel Time= 2.4 min
Peak Storage= 966 cf @ 12.20 hrs
Average Depth at Peak Storage= 0.27'
Bank-Full Depth= 2.00' Flow Area= 44.0 sf, Capacity= 734.43 cfs
14.00' x 2.00' deep channel, n= 0.022 Earth, clean & straight
Side Slope Z-value= 5.0 3.0 '/' Top Width= 30.00'
Length= 240.0' Slope= 0.0375 '/'
Inlet Invert= 325.00', Outlet Invert= 316.00'
Reach DD: Diversion Ditch
Hydrograph
r,Inflow
22- 20.83 cfs f� � 4 4 � ❑outflo23 An RR w
21 n to �1C@a=9.&48ac
19_ I %� H ,Svc, Fkno pth=b.2tr'
18_
17= % I I —I - MaXI-/e=54 74 s-
16
15 I —I rt fi fi 111=9.$22-
14
13
gr-
" 10_ %� _ rt fi � t )I-J
8_ ØØ,
I I 4 4 d— l 1
I1rtrtrtfi
0
0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180
Time (hours)

20241024_Harnett County_NW CC_Construction Con Type II 24-hr 25y 24h Rainfall=6.75"
Prepared by HDR, Inc Printed 10/28/2024
HydroCAD® 10.00-20 s/n 11397 ©2017 HydroCAD Software Solutions LLC Page 54
Summary for Reach SO: Access Drive Swale
Inflow Area = 2.296 ac, 6.53% Impervious, Inflow Depth = 3.11" for 25y 24h event
Inflow = 10.89 cfs @ 12.02 hrs, Volume= 0.595 af
Outflow = 9.71 cfs @ 12.07 hrs, Volume= 0.595 af, Atten= 11%, Lag= 2.6 min
Routing by Dyn-Stor-Ind method, Time Span= 0.00-180.00 hrs, dt= 0.01 hrs
Max. Velocity= 1.99 fps, Min. Travel Time= 4.5 min
Avg. Velocity = 0.51 fps, Avg. Travel Time= 17.8 min
Peak Storage= 2,638 cf @ 12.07 hrs
Average Depth at Peak Storage= 0.73'
Bank-Full Depth= 2.00' Flow Area= 21.0 sf, Capacity= 72.46 cfs
4.50' x 2.00' deep channel, n= 0.030 Short grass
Side Slope Z-value= 3.0 '/' Top Width= 16.50'
Length= 540.0' Slope= 0.0037 '/'
Inlet Invert= 358.00', Outlet Invert= 356.00'
Reach SO: Access Drive Swale
Hydrograph
❑Inflow
12- 10.89 cfs - Eloutflow
ni o lRtL Are 2 2.76_ c_
10
j
9.71 cfs Svc, . F�ev�p�Erptl�= 7�i'
I I - H H H MaxWet=199-f s
$- I /
I � _ I I I I I I I I m=Q•�I�
3 6
_ /' I I IAA H L 1-1=54o.9'
5- I I - H H 5=0.0037 '/'
4- I I —I 7 Ca�acity=72.46 cfs
3-
2-
0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180
Time (hours)

20241024_Harnett County_NW CC_Construction Con Type 1124-hr 25y 24h Rainfall=6.75"
Prepared by HDR, Inc Printed 10/28/2024
HydroCAD® 10.00-20 s/n 11397 ©2017 HydroCAD Software Solutions LLC Page 55
Summary for Reach S1: Swale
Inflow Area = 6.362 ac, 0.00% Impervious, Inflow Depth = 3.11" for 25y 24h event
Inflow = 25.18 cfs @ 12.06 hrs, Volume= 1.648 of
Outflow = 25.00 cfs @ 12.08 hrs, Volume= 1.648 af, Atten= 1%, Lag= 0.8 min
Routing by Dyn-Stor-Ind method, Time Span= 0.00-180.00 hrs, dt= 0.01 hrs
Max. Velocity= 6.11 fps, Min. Travel Time= 1.1 min
Avg. Velocity = 1.77 fps, Avg. Travel Time= 3.7 min
Peak Storage= 1,596 cf @ 12.08 hrs
Average Depth at Peak Storage= 0.59'
Bank-Full Depth= 2.00' Flow Area= 28.0 sf, Capacity= 340.18 cfs
4.00' x 2.00' deep channel, n= 0.022 Earth, clean & straight
Side Slope Z-value= 5.0 '/' Top Width= 24.00'
Length= 390.0' Slope= 0.0269 '/'
Inlet Invert= 330.50', Outlet Invert= 320.00'
7%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%\
Reach S1: Swale
Hydrograph
F
rl Inflow
28A.18 cfS 0 outflow
26, 25.00 cfs
24= I AV FrovIrDpth=b.5b'
22_ I //��
20= /�/ — —L 4 + T MxWA 1 4 s-
18_ T T T T T T T O.O 2
14 �-
14- tH=390.Q'
a 12- T T�=CitCf2 ,/,
appci =34�1 c s
6= T T T
4-
0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180
Time (hours)

20241024_Harnett County_NW CC_Construction Con Type 1124-hr 25y 24h Rainfall=6.75"
Prepared by HDR, Inc Printed 10/28/2024
HydroCAD® 10.00-20 s/n 11397 ©2017 HydroCAD Software Solutions LLC Page 56
Summary for Reach S2: CC Swale
Inflow Area = 6.362 ac, 0.00% Impervious, Inflow Depth = 3.11" for 25y 24h event
Inflow = 25.47 cfs @ 12.05 hrs, Volume= 1.648 af
Outflow = 25.18 cfs @ 12.06 hrs, Volume= 1.648 af, Atten= 1%, Lag= 0.9 min
Routing by Dyn-Stor-Ind method, Time Span= 0.00-180.00 hrs, dt= 0.01 hrs
Max. Velocity= 5.98 fps, Min. Travel Time= 1.3 min
Avg. Velocity = 1.88 fps, Avg. Travel Time= 4.0 min
Peak Storage= 1,916 cf @ 12.06 hrs
Average Depth at Peak Storage= 0.74'
Bank-Full Depth= 1.00' Flow Area= 7.0 sf, Capacity= 49.84 cfs
2.00' x 1.00' deep channel, n= 0.022 Earth, clean & straight
Side Slope Z-value= 5.0 '/' Top Width= 12.00'
Length= 455.0' Slope= 0.0233 '/'
Inlet Invert= 345.00', Outlet Invert= 334.40'
7%%%%%%%%%%%%%%%* *%%-%%%%%%%\
Reach S2: CC Swale
Hydrograph
r,Inflow
28 / 25.47 cfs ❑outflow
26. 25.18 cfs
24_ H Avgt Ft Dpth=b.7V'
22= I —I 7 MaxN 5 98 s
20- //
18= / 7 7 r =0.$22-
14 H =45.9'
o
12 7 7 `OtO
10_ — Ea9484cf�
8-
7 7 7
4-
0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180
Time (hours)

20241024_Harnett County_NW CC_Construction Con Type II 24-hr 25y 24h Rainfall=6.75"
Prepared by HDR, Inc Printed 10/28/2024
HydroCAD® 10.00-20 s/n 11397 ©2017 HydroCAD Software Solutions LLC Page 57
Summary for Pond 1 P: Pond
[62] Hint: Exceeded Reach S1 OUTLET depth by 5.51' @ 24.76 hrs
Inflow Area = 8.123 ac, 0.00% Impervious, Inflow Depth = 2.96" for 25y 24h event
Inflow = 30.53 cfs @ 12.06 hrs, Volume= 2.004 af
Outflow = 7.12 cfs @ 12.44 hrs, Volume= 1.580 af, Atten= 77%, Lag= 22.8 min
Primary = 7.12 cfs @ 12.44 hrs, Volume= 1.580 af
Secondary = 0.00 cfs @ 0.00 hrs, Volume= 0.000 af
Routing by Dyn-Stor-Ind method, Time Span= 0.00-180.00 hrs, dt= 0.01 hrs
Starting Elev= 322.14' Surf.Area= 8,230 sf Storage= 14,450 cf
Peak Elev= 325.76' @ 12.44 hrs Surf.Area= 14,354 sf Storage= 54,258 cf (39,808 cf above start)
Flood Elev= 327.00' Surf.Area= 17,014 sf Storage= 73,645 cf (59,195 cf above start)
Plug-Flow detention time= 1,901.9 min calculated for 1.249 af(62% of inflow)
Center-of-Mass det. time= 1,389.8 min ( 2,238.7 - 848.9 )
Volume Invert Avail.Storage Storage Description
#1 318.50' 73,645 cf Custom Stage Data (Prismatic)Listed below (Recalc)
Elevation Surf.Area Inc.Store Cum.Store
(feet) (sq-ft) (cubic-feet) (cubic-feet)
318.50 1,496 0 0
319.00 1,770 817 817
320.00 2,590 2,180 2,997
321.00 4,996 3,793 6,790
322.00 8,046 6,521 13,311
323.00 9,363 8,705 22,015
324.00 10,855 10,109 32,124
325.00 12,730 11,793 43,917
326.00 14,856 13,793 57,710
327.00 17,014 15,935 73,645
Device Routing Invert Outlet Devices
#1 Primary 318.00' 24.0" Round Culvert
L= 66.0' RCP, square edge headwall, Ke= 0.500
Inlet/ Outlet Invert= 318.00' / 317.00' S= 0.0152 '/' Cc= 0.900
n= 0.011 Concrete pipe, straight & clean, Flow Area= 3.14 sf
#2 Device 1 322.14' 0.5" Vert. Orifice/Grate X 3.00 C= 0.600
#3 Device 1 325.50' 48.0" x 48.0" Horiz. Orifice/Grate C= 0.600
Limited to weir flow at low heads
#4 Secondary 326.50' 25.0' long x 15.0' breadth Broad-Crested Rectangular Weir
Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60
Coef. (English) 2.68 2.70 2.70 2.64 2.63 2.64 2.64 2.63

20241024_Harnett County_NW CC_Construction Con Type II 24-hr 25y 24h Rainfall=6.75"
Prepared by HDR, Inc Printed 10/28/2024
HydroCAD® 10.00-20 s/n 11397 ©2017 HydroCAD Software Solutions LLC Page 58
Primary OutFlow Max=7.12 cfs @ 12.44 hrs HW=325.76' TW=316.77' (Dynamic Tailwater)
L =Culvert (Passes 7.12 cfs of 39.34 cfs potential flow)
2=Orifice/Grate (Orifice Controls 0.04 cfs @ 9.14 fps)
3=Orifice/Grate (Weir Controls 7.08 cfs @ 1.68 fps)
Secondary OutFlow Max=0.00 cfs @ 0.00 hrs HW=322.14' TW=325.00' (Dynamic Tailwater)
4-4=Broad-Crested Rectangular Weir( Controls 0.00 cfs)
Pond 1 P: Pond
Hydrograph
AI I F T I
30.53 cfs •OutflowInflow
_G' / 7 7 — ❑
Inflow Area&.1123 a�C ❑Primary
34_ z / ❑Secondary
30 / /- F F Peak Elev=325.76'
28= / /I I F F 1 1 Storage=54,258 cf
26 / ,
22V / � - I T IT T
20;/ / % I I T T 17 1 17 T F 1 1T
.!, 18
0 16_ / /— I T T 17 17 71 7 T F 71717
"' 14: / —
1210v1v 7.1 219 cfs rf 1- 1 71 T T 1F 17 71 7 T F 71717
8 / /
61
0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180
Time (hours)

20241024_Harnett County_NW CC_Construction Con Type II 24-hr 25y 24h Rainfall=6.75"
Prepared by HDR, Inc Printed 10/28/2024
HydroCAD® 10.00-20 s/n 11397 ©2017 HydroCAD Software Solutions LLC Page 59
Summary for Pond C 1: Replaced Culvert
[62] Hint: Exceeded Reach DO OUTLET depth by 1.55' @ 12.09 hrs
[61] Hint: Exceeded Reach SO outlet invert by 0.67' @ 12.09 hrs
Inflow Area = 8.553 ac, 1.75% Impervious, Inflow Depth = 2.68" for 25y 24h event
Inflow = 28.18 cfs @ 12.09 hrs, Volume= 1.910 af
Outflow = 28.18 cfs @ 12.09 hrs, Volume= 1.910 af, Atten= 0%, Lag= 0.0 min
Primary = 28.18 cfs @ 12.09 hrs, Volume= 1.910 af
Secondary = 0.00 cfs @ 0.00 hrs, Volume= 0.000 af
Routing by Dyn-Stor-Ind method, Time Span= 0.00-180.00 hrs, dt= 0.01 hrs
Peak Elev= 356.67' @ 12.09 hrs
Flood Elev= 357.00'
Device Routing Invert Outlet Devices
#1 Primary 354.00' 30.0" Round Culvert
L= 137.0' RCP, end-section conforming to fill, Ke= 0.500
Inlet/Outlet Invert= 354.00' / 351.50' S= 0.0182 '/' Cc= 0.900
n= 0.012 Concrete pipe, finished, Flow Area= 4.91 sf
#2 Secondary 357.00' 50.0' long x 100.0' breadth Broad-Crested Rectangular Weir
Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60
Coef. (English) 2.68 2.70 2.70 2.64 2.63 2.64 2.64 2.63
Primary OutFlow Max=28.15 cfs @ 12.09 hrs HW=356.67' TW=352.98' (Dynamic Tailwater)
4-1=Culvert (Inlet Controls 28.15 cfs @ 5.73 fps)
Secondary OutFlow Max=0.00 cfs @ 0.00 hrs HW=354.00' TW=351.00' (Dynamic Tailwater)
2=Broad-Crested Rectangular Weir( Controls 0.00 cfs)

20241024_Harnett County_NW CC_Construction Con Type II 24-hr 25y 24h Rainfall=6.75"
Prepared by HDR, Inc Printed 10/28/2024
HydroCAD® 10.00-20 s/n 11397 ©2017 HydroCAD Software Solutions LLC Page 60
Pond C 1: Replaced Culvert
Hydrograph
A _L _L _L - _H -
/1 7R 1 R rfg E Inflow
A 751 1 R rf r - E Outflow
Nrfli4m Area=8.553 arc - ❑Primary
28.18 cfs ❑Secondary
30 %
28 I 7 I ea7k EIev=356.67'
26
24 I rt fi 1 —h fi fi I I H rt -
-
20;
i18 -/ + ]— + I —I —
16� —
014� / I —L ] -[ - 1 -1 —14
8 -/
6 -
4 - '/ / / / / /
0.00 cfs G / / / / / /rir//
0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180
Time (hours)

20241024_Harnett County_NW CC_Construction Con Type II 24-hr 25y 24h Rainfall=6.75"
Prepared by HDR, Inc Printed 10/28/2024
HydroCAD® 10.00-20 s/n 11397 ©2017 HydroCAD Software Solutions LLC Page 61
Summary for Pond C2: Proposed Culvert
[62] Hint: Exceeded Reach S2 OUTLET depth by 1.63' @ 12.06 hrs
Inflow Area = 6.362 ac, 0.00% Impervious, Inflow Depth = 3.11" for 25y 24h event
Inflow = 25.18 cfs @ 12.06 hrs, Volume= 1.648 af
Outflow = 25.18 cfs @ 12.06 hrs, Volume= 1.648 af, Atten= 0%, Lag= 0.0 min
Primary = 25.18 cfs @ 12.06 hrs, Volume= 1.648 af
Routing by Dyn-Stor-Ind method, Time Span= 0.00-180.00 hrs, dt= 0.01 hrs
Peak Elev= 336.77' @ 12.06 hrs
Flood Elev= 337.00'
Device Routing Invert Outlet Devices
#1 Primary 334.40' 30.0" Round Culvert
L= 45.0' RCP, end-section conforming to fill, Ke= 0.500
Inlet/Outlet Invert= 334.40' / 330.50' S= 0.0867 '/' Cc= 0.900
n= 0.012 Concrete pipe, finished, Flow Area= 4.91 sf
Primary OutFlow Max=25.15 cfs @ 12.06 hrs HW=336.76' TW=331.09' (Dynamic Tailwater)
4-1=Culvert (Inlet Controls 25.15 cfs @ 5.23 fps)
Pond C2: Proposed Culvert
Hydrograph
❑Inflow
28 7ri 1 R rf ❑Primary
26 25.18 cfs (' Inflow Area=6.362 ac
24 I Peak Elev=336.77'
22- I
20= I 30.0"
18- Round Culvert
w 16-
o
14- / n=0.012
IL 12- L=45.0'
$- S=0.O867 /
4- •
s
f 7Z/r
0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180
Time (hours)

Harnett County Solid Waste Department I Stormwater Permit Application—October 2024 I.)
Attachment E—Wet Pond Calculations J
Attachment E — Wet Pond
Calculations

Harnett County Solid Waste Department I Stormwater Permit Application—October 2024 I.)
Attachment E—Wet Pond Calculations J
This page intentionally left blank.

Harnett County Solid Waste Department I Stormwater Permit Application—October 2024 I.)
E.1 J
■
Attachment E.1 — Wet Pond
Design Calculations

Harnett County Solid Waste Department I Stormwater Permit Application-October 2024 Fn
Attachment E.1-Wet Pond Design Calculations
This page intentionally left blank.

Harnett County Solid Waste Convenience Center Wet Pond Calculations
Using Simple Run-off Calcuation to determine Design Volume
Simple Method for Runoff Volume
Rv = 0.05 + 0.9 * IA
Where: Rv = Runoff coefficient(unitless)
In = Impervious fraction(unitless)
DV = 3630 * RD * Rv * A
Where: DV = Design volume(cu ft)
RD = Design storm depth(in)
A = Drainage area(ac) \O(i I I j J /1
C
Where IA is 1.379/8.123 `C •0`i • X ''
Rv=0.05+0.9* la or 0.05 +0.9*(1.379/8.123) Q� J ;3r
Rv= 0.2027884 �•,�� �<`
`//
Then determine the design volume (Dv) •// • , •
�,
)02,02
Where RD is 1 inch
Dv=3630*Rd*Rv*A or 3630*1*0.203*8.123
Dv= 5,980
From Equation 1 in the NCDEQ stormwater Design Manual the main pool volume was determined using
Equation 1: Main Pool Volume, VMP
Vmp = 0.87 * T T * DV
Where: 0.87 = Factor to adjust for the volume in the forebay
VMP = Main pool volume,not including the forebay(cubic feet)
HRT = Required hydraulic residence time(14 days)
Ts = Average time between storm events(5 days)
DV = Design volume(cubic feet)
Vmp=0.87*(Hrt/Ts)*Dv or 0.87*(14/5)*5,980
Vmp= 14,566
The Average Depth is found using Equation 3

Equation 3. Average depth when the shelf is partially or fully submerged and
the shelf is being excluded from the average depth calculation
Vrr—Vshelf
Davg=
A hntttn,of chvlf
Where: Davy = Average depth(feet)
Vpp = Main pool volume at permanent pool elevation(feet3)
Vahelf = Volume over the shelf only(feet3)—see below
Abottom of snelf = Area of main pool at the bottom of the shelf(feet2)
Vsholf= 0.5'Depthmaa over shelf*Perimeterp.,m pool*Wldthwbm.,p.d part of shelf
Where: Depth., overanetl = Depth of water at the deep side of the shelf as
measured from the permanent pool(feet)
Perimeteroe,,,,pod = Perimeter of main pool at the bottom of the
shelf(feet)
Widthsphmemed pal of shelf = Width from the deep side to the dry side of the
shelf as measured at permanent pool(feet)
Where Vpp is= 14,581 CF
Vshelf is 0.5 x 1.0 X 235 If* 6 ft= 705
Area of Bottom of Shelf is 3003 sf
Davg= 4.62 ft
Sediment Storage is from EL 318.5 to 319.0
Sediment Storage=738 CF
Forebay Storage to be 15 to 20%of Wet Pond Storage
Wet Pond Storage = 14566 CF
Forebay Vol = 2184.9 to 2913.2 CF
Measured Forebay Volume= 2214 CF
Drawdown Time
(3) 1/2-inch Orifices at EL 322.14
Orifice Equation for Outlet Flow
An orifice is simply a hole. In the design of SCMs, orifices are often used for drawing down the
design volume. It is important to determine the size an orifice correctly so that the appropriate
detention time provided.
The basic equation for discharge from an orifice is:
Q = CD A (2 g Ho)o.5
Where: Q = Discharge(cfs)
CD = Coefficient of discharge per Table 6(unitless)
A = Cross-sectional area of orifice entrance(sq ft)
g = Acceleration of gravity(32.2 ft/sec2)
Ho = Driving head from water surface to centroid
orifice (ft) *usually use Hd3 to compute
drawdown through an orifice to reflect the fact
that head is decreasing as drawdown occurs*

Table 6: Values of Coefficient of Discharge for Orifices, CD
(Malcom 1989)
Entrance Condition CD
Typical default value 0.60
Square-edged entrance 0.59
Concrete pipe,grooved end 0.65
Corrugated metal pipe,mitred to slope 0.52
Corrugated metal pipe,projecting from fill 1.00
Figure 6: Schematic of Orifice Flow
(Malcom 1989)
Hu
Where Cd =0.60 and Ho is 2.11'
Q= 3x(0.60*(0.5/12)*(0.5/12)*3.14/4)*(2g*2.11/3)^0.5
Q= 0.0165099 cfs
Dv= 5,980 cf
Drawdown Time= 362178.7 sec
100.6052 HR
4.191883 days

SUPPLEMENT-EZ COVER PAGE
FORMS LOADED
PROJECT INFORMATION
1 Project Name Harnett County Northwest Convenience Center
2 Project Area(ac) 28.26
3 Coastal Wetland Area(ac) 0
4 Surface Water Area(ac) 0
5 Is this project High or Low Density? High
6 Does this project use an off-site SCM? No
COMPLIANCE WITH 02H.1003(4)
7 Width of vegetated setbacks provided(feet) 30
8 Will the vegetated setback remain vegetated? Yes
9 If BUA is proposed in the setback,does it meet NCAC 02H.1003(4)(c-d)? N/A
10 Is streambank stabilization proposed on this project? No
NUMBER AND TYPE OF SCMs:
11 Infiltration System
12 Bioretention Cell
13 Wet Pond 1
14 Stormwater Wetland
15 Permeable Pavement
16 Sand Filter
17 Rainwater Harvesting(RWH)
18 Green Roof
19 Level Spreader-Filter Strip(LS-FS)
20 Disconnected Impervious Surface(DIS)
21 Treatment Swale
22 Dry Pond
23 StormFilter
24 Silva Cell
25 Bayfilter
26 Filterra
FORMS LOADED
DESIGNER CERTIFICATION
27 Name and Title: Jeffrey S.Murray,Vice President
28 Organization: HDR Engineering,Inc.of the Carolinas
29 Street address: 555 Fayetteville Street,Suite 900
30 City,State,Zip: Raleigh,NC 27601
31 Phone number(s): 919-232-6682
32 Email: [e-mail]
Certification Statement:
I certify,under penalty of law that this Supplement-EZ form and all supporting information were prepared under my direction or supervision;that the
information provided in the form is,to the best of my knowledge and belief,true,accurate,and complete;and that the engineering plans,
specifications,operation and maintenance agreements and other supporting information are consistent with the information provided here.
Designer
��\\,\1 i( 1jr)f•/f`f
0,7 .i ' , Sig ue f ner
�hyr
16/47ZT
Seal Date

DRAINAGE AREAS
1 Is this a high density project? Yes
2 If so,number of drainage areas/SCMs _ 0
3 Does this project have low density areas? _ No
4 If so,number of low density drainage areas _ 1
Is all/part of this project subject to previous rule
5 versions? No
CLICK TO LOAD FORM
DRAINAGE AREA INFORMATION Entire Site LD 1
4 Type of SCM NA Wet Pond
5 Total drainage area(sq ft) 1231005 _ 353846
6 Onsite drainage area(sq ft) 1231005 353846
7 Offsite drainage area(sq ft) 0 0
8 Total BUA in project(sq ft) 78190 sf 78190 sf
New BUA on subdivided lots(subject to
9 permitting)(sq ft)
New BUA not on subdivided lots(subject to
10 permitting)(sf) 78190 sf 78190 sf
11 Offsite BUA(sq ft) sf sf
12 Breakdown of new BUA not on subdivided lots:
-Parking(sq ft) 43300 sf 43300 sf
-Sidewalk(sq ft)
-Roof(sq ft) 100 sf 10 sf
-Roadway(sq ft) 34790 sf 34790 sf
-Future(sq ft)
-Other,please specify in the comment box
below(sq ft)
New infiltrating permeable pavement on
13 subdivided lots(sq ft) sf sf
New infiltrating permeable pavement not on
14 subdivided lots(sq ft) sf sf
Existing BUA that will remain(not subject to
15 permitting)(sq ft) sf sf
16 Existing BUA that is already permitted(sq ft) sf sf
17 Existing BUA that will be removed(sq ft) sf sf
18 Percent BUA 6% 22%
19 Design storm(inches) 1.0 in 1.0 in
20 Design volume of SCM(cu ft) 5980 cf
21 Calculation method for design volume 3630*Rd*Rv*A
ADDITIONAL INFORMATION
Please use this space to provide any additional information about the
22 drainage area(s):
A single drainage area is connected to the Wet Pond. Subareas were
delineated in the HydroCAD analysis for purposes of sizing conveyance
channels and piping for the 25-year,24-hour storm.

Disturbed Drainage Area Built Upon
Site Area Area to SCM1 Area
SF 1,231,006 256,133 353,846 78,190
AC 28.26 5.88 8.12 1.79
1 Drainage Area 1.1, 2, and 3

WET POND
1 Drainage area number A
2 Minimum required treatment volume(cu ft)
GENERAL MDC FROM 02H.1050
3 Is the SCM sized to treat the SW from all surfaces at build-out? Yes
4 Is the SCM located away from contaminated soils? Yes
5 What are the side slopes of the SCM(H:V)? 3:1
Does the SCM have retaining walls,gabion walls or other
6 No
engineered side slopes?
Are the inlets,outlets,and receiving stream protected from erosion
7 Yes
(10-year storm)?
8 Is there an overflow or bypass for inflow volume in excess of the Yes
design volume?
9 What is the method for dewatering the SCM for maintenance? Drawdown Orifice
10 If applicable,will the SCM be cleaned out after construction? Yes
11 Does the maintenance access comply with General MDC(8)? Yes
12 Does the drainage easement comply with General MDC(9)? _ N/A
If the SCM is on a single family lot,does(will?)the plat comply with
13 N/A
General MDC(10)?
14 Is there an O&M Agreement that complies with General MDC(11)? Yes
15 Is there an O&M Plan that complies with General MDC(12)? Yes
16 Does the SCM follow the device specific MDC? Yes
17 Was the SCM designed by an NC licensed professional? Yes
WET POND MDC FROM 02H.1053
18 Sizing method used SA/DA
19 Has a stage/storage table been provided in the calculations? _ Yes
20 Elevation of the excavated main pool depth(bottom of sediment 318.50
removal)(fmsl)
21 Elevation of the main pool bottom(top of sediment removal)(fmsl) 319.00
22 Elevation of the bottom of the vegetated shelf(fmsl) 321.00
23 Elevation of the permanent pool(fmsl) _ 322.14
24 Elevation of the top of the vegetated shelf(fmsl) 322.00
25 Elevation of the temporary pool(fmsl) 324.25
26 Surface area of the main permanent pool(square feet) 4066
27 Volume of the main permanent pool(cubic feet) 14581 cf
28 Average depth of the main pool(feet) 4.62 ft
29 Average depth equation used Equation 3
30 If using equation 3,main pool perimeter(feet) 235.0 ft
31 If using equation 3,width of submerged veg.shelf(feet) 6.0 ft
32 Volume of the forebay(cubic feet) 2214 cf
33 Is this 15-20%of the volume in the main pool? Yes
34 Clean-out depth for forebay(inches) 24 in
35 Design volume of SCM(cu ft) 5980 cf
36 Is the outlet an orifice or a weir? Orifice
37 If orifice,orifice diameter(inches) (3)0.5 Inch Orifices
38 If weir,weir height(inches)
39 If weir,weir length(inches)
40 Drawdown time for the temporary pool(days) 4
41 Are the inlet(s)and outlet located in a manner that avoids short- Yes
circuiting?
42 Are berms or baffles provided to improve the flow path? Yes
43 Depth of forebay at entrance(inches) 24 in
44 Depth of forebay at exit(inches) _ 12 in
45 Does water flow out of the forebay in a non-erosive manner? Yes
46 Width of the vegetated shelf(feet) 6 ft
47 Slope of vegetated shelf(H:V) 6:1
48 Does the orifice drawdown from below the top surface of the No
permanent pool?
49 Does the pond minimize impacts to the receiving channel from the 1- Yes
yr,24-hr storm?
50 Are fountains proposed?(If Y,please provide documentation that No
MDC(9)is met.)
51 Is a trash rack or other device provided to protect the outlet system? Yes
52 Are the dam and embankment planted in non-clumping turf grass? Yes
53 Species of turf that will be used on the dam and embankment Fescue/Bermuda
54,Has a planting plan been provided for the vegetated shelf? Yes
ADDITIONAL INFORMATION
Please use this space to provide any additional information about
55 the wet pond(s):
2

Harnett County Solid Waste Department I Stormwater Permit Application-October 2024 Fn
Attachment E.1-Wet Pond Design Calculations
This page intentionally left blank.

Harnett County Solid Waste Department I Stormwater Permit Application—October 2024 I.)
E.2 J
■
Attachment E.2 — NCDEQ
SCM C-3 Wet Pond

Harnett County Solid Waste Department I Stormwater Permit Application—October 2024 I.)
Attachment E.2—NCDEQ SCM C-3 Wet Pond J
This page intentionally left blank.

IC
Fn vironmental
NCDEQ Stormwater Design Manual Quality
C-3. Wet Pond
•
TO-2 it ilk . 1
r.
,4 4,, •,.-,I,'t-,
. ! J �y
►,1
41
I '1 . . - 4•'�'*''or � i#. A ! e + tom- .�
F * * .•,.
Design Objective
A wet pond shall be designed to capture the design storm and release it slowly over a period of two to
five days via a properly design outlet structure. The first outlet in the structure is designed to be above
the bottom of the pond, thus creating a permanent pool of water. Stormwater shall have an adequate
flow path to bring about removal of TSS through dilution and settling. The pond shall be designed in a
manner that protects the device, the areas around the device and the receiving stream from erosion.
The pond also must be maintained properly to prevent the resuspension of captured sediments.
Design Volume
The design volume for a wet pond is equivalent to the volume that is retained for a two to five-day
period between the temporary pool elevation and the permanent pool elevation.
Important Links
Rule 15A NCAC 2H .1053. MDC for Wet Ponds
SCM Credit Document, C-3. Credit for Wet Ponds
C-3. Wet Pond 1 Revised: 11-23-2020

Fn vironmental
NCDEQ Stormwater Design Manual Quality
Table of Contents
Guidance on the MDC
MDC 1: Main Pool Surface Area and Volume
MDC 2: Main Pool Depth
MDC 3: Sediment Storage
MDC 4: Location of Inlet(s) and Outlet
MDC 5: Forebay
MDC 6: Vegetated Shelf
MDC 7: Drawdown Time
MDC 8: Protection of the Receiving Stream
MDC 9: Fountains
MDC 10: Trash Rack
MDC 11: Vegetation
Recommendations
Recommendation 1: Outlet Structure
Recommendation 2: Emergency Spillway
Recommendation 3: Irrigation
Recommendation 4: Safety
Recommendation 5: Temperature Control
Design Variants
Maintenance
Old Versus New Design Standards
i
� I
it
J ,
I
1 _ 1
o.s ` , i . yi r V t A4 u .—i , � gy p � �p- a' -, , t' g& iM
' �, ` m -J 40't" r lP. � 4. * �' 7y ,`k " t 4 ,' ,. a� ryLi Y-0 M1a )/� 1 `e s F, r -V., , —_-` ---- 'rt l gP t' '' : ro , ,y , i'+ i `- -
ir
44 fi '' � + •t �'_n.
-ter a
o _
C-3. Wet Pond 2 Revised: 11-23-2020

NZ, Environmental
Quality
NCDEQ Stormwater Design Manual Environmental
Figure 1: Wet Pond Example: Plan View
FOUNTAIN(OPTIONAL FEATURE) // � /
VERIFY EROSION AND RE-SUSPENSION ' / j"///
OF SEDIMENT WILL NOT OCCUR; // /
DO NOT PLACE NEAR OUTLET J// //
/ , /
MAIN POOL /i4 SCM MAINTENANCE AND
SURFACE AREA AND VOLUME SIZED USING EITHER: // ACCESS EASEMENT
(a) HYRDAULIC RETENTION TIME METHOD;or /
(b) THE SA/DA AND AVERAGE DEPTH METHOD
VEGETATED SHELF e `� 15 FOREBAY PERCENT
MINIMUM WIDTH:6 FT
MAXIMUM SLOPE:6 H:1 V OF MAIN POOL
/ VOLUME
VEGETATED SIDE SLOPES
RECOMMENDED SLOPE:3 H:1 V / \
PLANTED WITH NON-CLUMPING TURF GRASS
TREES AND WOODY SHELVES NOT ALLOWED/
OUTLET STRUCTURE _`
PLACE INLETS AND ag
OUTLETS TO AVOID it /)
SHORT-CIRCUTING AND •,%3.
DESIGN FOR EROSION 1 PROTECTION I INLET STRUCTU
JI /, PLACE INLETS D
OUTLETS TO AVOID
/ SHORT-CIRCUTING
` AND DES
btift
/ �' • `% EROSION
FOR
PROTECTION
EMERGENCY SPILLWAY ill li
PROVIDED FOR MAJOR
STORMS AND DESIGNED r TRANSITION FROM FOREBAY TO
FOR EROSION / MAIN POOL SHALL FLOW AT A
PROTECTION / NON-EROSIVE VELOCITY
/
C-3. Wet Pond 3 Revised: 11-23-2020

Environmental
NCDEQ Stormwater Design Manual Qaaliry
Figure 2: Wet Pond Example: Cross-Section View 1
FOREBAY MAIN POOL SURFACE AREA AND VOLUME
(a)15 TO 20 PERCENT OF MAIN POOL VOLUME SURFACE AREA AND VOLUME SIZED USING EITHER:
(b)ENTRANCE SHALL BE DEEPER THAN EXIT (a)HYDRAULIC RETENTION TIME METHOD:OR
(c)WATER FLOWING OVER FOREBAY DAM (b)THE SA/DA AND AVERAGE DEPTH METHOD
SHALL FLOW AT NON-EROSIVE VELOCITY
(d)IF DEPTH<30 INCHES,CLEAN OUT
FOREBAY EMBANKMENT
MIN.WIDTH:
10 FT FOR
TEMPORARY POOL EMERGENCY SPILLWAY MAINTENANCE
DESIGN TO DRAW ACCESS
DOWN BETWEEN
TWO AND FIVE
DAYS p�
•
(,)
14/
(2-
MIN:6'
TEMPORARY POOL
MAIN POOL \
/,/ N
//2// o
///'//
/ /// /
/7"//••//'/ i // %////j%�/
/// // // // / / // // //
//// / / ////////// / ////// /
/ •
// // // /// /./ / /// // // //r j/ /// // /•/ // •/ •/// /•// •// // /•// //
/ /// •////// //- // / ///////// ///� /// /// / /// ///,// // /// /// ///// //
/// // // /// // '`��// // // /// / ////////////- // /// // /// // /// /// // // ///
•////// //%///////, %// %%///////// //'////////// ///�//////////%/ /////////%/////////////////
//// // // // // // /// // /. .. // /// / //// /// /// / ,/ /// / // / ,/ ///
//v/% ///////////j ////// ///////// ////4///////// // /////////j// j ///////////// // ///
////// ///////////////// //////// /// //j/// / // ///////// // ////////////////// ///'
////// ///////////////// ////// ////%////// / ////////////////// ////////////// //////////
/////// ////////////// // ////// /// /// /// / //// /// /// // / // // // // /
,// /// // ////////////// //// //////////////// ////////////////// ///////////////////////
/////// /j//////////////%/ /j j�///%////////////j//////////j///// ////j///%///j%///j�/%
VEGETATED SIDE SLOPES SEDIMENT STORAGE MAIN POOL DEPTH VEGETATED SHELF
RECOMMENDED SLOPE:3 H:1 V MINIMUM SEDIMENT AVG.DEPTH:3'TO 8' MINIMUM WIDTH:6 FT
PLANTED WITH NON-CLUMPING STORAGE DEPTH OF 6" "OPTION TO EXCLUDE MAXIMUM SLOPE:6 H:1 V
TURF GRASS;TREES AND SUBMERGED PORTION VEGETATION:MINIMUM OF 3
WOODY SHELVES NOT OF VEG.SHELF FROM DIVERSE SPECIES OF
ALLOWED CALCULATIONS HERBACEOUS,NATIVE
SPECIES;MIN.50 PLANTS
PER 200 SF OF SHELF
C-3. Wet Pond 4 Revised: 11-23-2020

Environmental
NCDEQ Stormwater Design Manual Quality
Figure 3: Wet Pond Example: Cross-Section View 2
VEGETATED SHELF
MINIMUM WIDTH:6 FT
MAXIMUM SLOPE:6 H:1 V
OUTLET STRUCTURE
MUST BE SIZED TO: VEGETATED SIDE SLOPES
(a)DRAWDOWN TEMPORARY RECOMMENDED SLOPE:3 H:1 V
POOL IN TWO TO FIVE DAYS TRASH RACK FRONT AND BACK EMBANKMENT SLOPE
(b)DISCHARGE RUNOFF FROM REQUIRED REQUIRED TO BE VEGETATED
1-YR,24-HR STORM TO MINIMIZE
HYDROLOGIC IMPACTS
6'MIN. EMBANKMENT
SH LF WIITH MINIMUM WIDTH:10 FT FOR
MAINTENANCE ACCESS
TEMPORARY POOL
PROPOSED GRADE
MAIN POOL 1111
OUTLET PIPE
EXISTING GRADE
F/1/, /,- /// ///r////,- /// / //
DEWATERING METHOD
WET PONDS SHALL HAVE A METHOD TO DRAW DOWN STANDING WATER TO
FACILITATE MAINTENANCE AND INSPECTION
MIN.6"SEDIMENT (E.G.,SKIMMER OR PUMP)
STORAGE
Figure 4: Wet Pond Example: Outlet Structure
TRASH RACK(REQUIRED)
WEIR(OR OTHER METHOD)
TO ESTABLISH
TEMPORARY POOL
RISER CREST
ORIFICE
OUTLET TO ESTABLISH TEMPORARY POOL \ "\
NORMAL POOL
NNH
MUST DRAW DOWN
TEMPORARY POOL IN NORMAL POOL I
TWO TO FIVE DAYSail
Illy-� T - - - - - - -
\//\//\//\//\//\� \i\i.i,�i/p�i/• OUTLET PIPE
DEWATERING METHOD
WET PONDS SHALL HAVE • 1
METHOD TO DRAW DOWN
STANDING WATER TO t i
FACILITATE MAINTENANCE
AND INSPECTION(E.G.,
SKIMMER OR PUMP)
ANTI-FLOTATION SLAB ANTI-SEEP MEASURES
ARE RECOMMENDED
C-3. Wet Pond 5 Revised: 11-23-2020

NC Environmental
NCDEQ Stormwater Design Manual Qaaliry
Guidance on the MDC
MDC 1. MAIN POOL SURFACE AREA AND VOLUME.
The main pool of the wet pond shall be sized using either:
(a) The Hydraulic Retention Time (HRT) Method; or
(b) The SA/DA and Average Depth Method.
The calculation of the volume or area of the main pool under this MDC does not include the
volume or area of the forebay. The forebay will be added to the main pool per MDC 5 below.
The Hydraulic Retention Time (HRT) Method is based on setting a ratio between the permanent
pool and temporary pool volume that results in a stormwater residence time of at least 14 days.
This method does not create a direct correlation between the pond's surface area and average
depth but instead allows the designer to determine the pond geometry that works best for the
site.
Ponds designed under the HRT Method will typically have an average depth of eight feet or
less. If a pond's average depth does exceed eight feet, then the equation below shall only apply
to the portion of the pond that is above the eight-foot average depth threshold. (In other words,
the deep portions of the main pool shall not be considered to provide pollutant removal.)
The total main pool volume is determined by the following equation:
Equation 1: Main Pool Volume, VMP
VMP = 0.87 * HRT * DV
s
Where: 0.87 = Factor to adjust for the volume in the forebay
VMP = Main pool volume, not including the forebay (cubic feet)
HRT = Required hydraulic residence time (14 days)
Ts = Average time between storm events (5 days)
DV = Design volume (cubic feet)
The SA/DA Tables with Average Depth Method is based on providing a minimum surface
area to drainage area ratio depending on the percent imperviousness in the drainage area and
on the average depth of the pond. The required minimum percentages are outlined in Table 1
(Piedmont and Mountains) and Table 2 (Coastal). Because these numbers are expressed as
percentages, the required surface area of the wet pond would be calculated by multiplying the
drainage area by the value found in Table 1 or Table 2, and then dividing the result by 100.
C-3. Wet Pond 6 Revised: 11-23-2020

Environmental
NCDEQ Stormwater Design Manual Quality
Table 1: Piedmont and Mountain SA/DA Table (Adapted from Driscoll, 1986)
Percent Permanent Pool Average Depth (ft)
Impervious
Cover 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
Table 2: Coastal SA/DA Table (Adapted from Driscoll, 1986)
Percent Permanent Pool Average Depth (ft)
Impervious
Cover 3.0 4.0 5.0 6.0 7.0 >_8.0
10% 0.78 0.61 0.44 0 0 0
20% 1.48 1.04 0.87 0.70 0.52 0.35
30% 2.18 1.65 1.39 1.13 0.87 0.70
40% 2.96 2.26 1.83 1.39 0.96 0.78
50% 3.65 2.87 2.35 1.83 1.31 0.96
60% 4.35 3.31 2.78 2.26 1.74 1.13
70% 5.22 3.92 3.22 2.52 1.83 1.31
80% 5.92 4.52 3.65 2.78 1.91 1.57
90% 6.53 5.05 4.18 2.96 2.44 1.74
100% 7.13 5.92 4.87 3.83 2.78 1.83
C-3. Wet Pond 7 Revised: 11-23-2020

Environmental
NCDEQ Stormwater Design Manual Qaaliry
MDC 2: MAIN POOL DEPTH.
The average depth of the main pool shall be three to eight feet below the permanent pool
elevation. The applicant shall have the option of excluding the submerged portion of the
vegetated shelf from the calculation of average depth.
Depth is an important engineering design criterion because most of the pollutants are removed
through settling through the water column. Very shallow wet ponds may develop currents that
can re-suspend materials; on the other hand, very deep wet ponds can become thermally
stratified or anoxic and release pollutants back into the water.
When calculating the average depth, only the main pool is considered. The forebay is excluded
from the calculation. Depths between 8 and 20 feet may be allowed when an existing
excavated area is being converted to a wet pond. For ponds deeper than 8 feet, only the main
pool volume in the first 8 feet of depth may be used for the HRT method and the 8.0-foot depth
column should be used for the SA/DA method.
Because the cross-sectional area of a wet pond generally varies with depth, the average depth
of the wet pond is not equal to the total depth from the main pool surface to the bottom of the
pond. The average depth must be calculated using either Equation 2 or Equation 3 below.
Equation 2 calculates a ratio of the total volume of the main pool to its surface area, and can be
used for all wet pond designs. When all or part of the vegetated shelf is submerged, designers
have the option to use Equation 3. In Equation 3, the volume of water above the vegetated
shelf is excluded from the calculation.
Equation 2. Average depth when the shelf is not submerged or
the shelf is being included in the average depth calculation
VPP
Davg = SA
Where: Davg = Average depth (feet)
VPP = Main pool volume at permanent pool elevation (feet3)
SA = Main pool area at permanent pool elevation (feet2)
C-3. Wet Pond 8 Revised: 11-23-2020

Environmental
NCDEQ Stormwater Design Manual Qaaliry
Equation 3. Average depth when the shelf is partially or fully submerged and
the shelf is being excluded from the average depth calculation
VPP—Vshelf
Davg =
Abottom of shelf
Where: Davg = Average depth (feet)
VPP = Main pool volume at permanent pool elevation (feet3)
Vshelf = Volume over the shelf only (feet3)—see below
Abottom of shelf = Area of main pool at the bottom of the shelf (feet2)
Vshelf= 0.5 * Depthmax over shelf* Perimeterperm pool * Widthsubmerged part of shelf
Where: Depthmax over shelf = Depth of water at the deep side of the shelf as
measured from the permanent pool (feet)
Perimeterperm pool = Perimeter of main pool at the bottom of the
shelf(feet)
Widthsubmerged part of shelf = Width from the deep side to the dry side of the
shelf as measured at permanent pool (feet)
MDC 3: SEDIMENT STORAGE.
The forebay and main pool shall have a minimum sediment storage depth of six inches.
To achieve this goal, the designer should design the entire wet pond per the MDC and then add
an additional six inches to the depth for sediment storage. In other words, the six-inch depth for
sediment storage must be excluded when calculating the average depth of the wet pond and
when using the HRT Method. It is recommended to consider adding more depth to reduce the
frequency of cleanouts required for the wet pond.
MDC 4: LOCATION OF INLET(S) AND OUTLET.
The inlet(s) and outlet shall be located in a manner that avoids short circuiting.
The most direct way of maximizing the flow path between the inlet and the outlet is to design a
long, narrow pond. In fact, long and narrow but irregularly shaped wet ponds usually appear
more natural and therefore may have increased aesthetic value. If local site conditions prohibit a
relatively long, narrow facility, baffles may be placed in the wet pond to lengthen the stormwater
flow path as much as possible. Baffles should extend to at least the temporary pool elevation.
Where possible, the width of the pond should expand near the outlet to facilitate settling.
C-3. Wet Pond 9 Revised: 11-23-2020

NC Environmental
NCDEQ Stormwater Design Manual Qaaliry
MDC 5: FOREBAY.
A forebay that meets the following specifications shall be included:
(a) Forebay volume shall be 15 to 20 percent of the volume in the main pool;
(b) The forebay entrance shall be deeper than the forebay exit;
(c) The water flowing over or through the structure that separates the forebay from the
main pool shall flow at a nonerosive velocity; and
(d) If sediment accumulates in the forebay in a manner that reduces its depth to less than
75 percent of its design depth, then the forebay shall be cleaned out and returned to its
design state.
Forebays are required on all inlets to a wet pond to collect sediment for easier removal and to
dissipate the flow energy prior to the stormwater entering the main part of the wet pond. The
forebay should be configured for energy dissipation to avoid re-suspension of sediment
previously captured in the forebay. One of several engineering means of energy dissipation is
to have the inlet pipe submerged below the permanent forebay pool level, provided that the inlet
placement does not serve to re-suspend previously captured sediment.
The volume for the forebay shall be 15 to 20°/0 of the main pool volume. If the pond has more
than one forebay, then the total volumes of the forebays shall be 15 to 20% of the main pool
volume. See Figure 5 for guidance on forebay design.
Figure 5: Forebay Diagram
Influent stormwater To main pool
Thr
•
I .........,,
60 in 40 in
MDC 6: VEGETATED SHELF.
The main pool shall be equipped with a vegetative shelf around its perimeter. The minimum
width of the vegetated shelf shall be six feet and the slope shall be no steeper than 6:1
(horizontal to vertical).
The designer may choose the precise placement of the vegetated shelf with regard to the top of
the permanent pool. The vegetated shelf may be completely submerged with the permanent
pool perimeter as its outer boundary, completely above the permanent pool with the permanent
pool perimeter as its inner boundary, or partially submerged at permanent pool. A vegetated
C-3. Wet Pond 10 Revised: 11-23-2020

Fn vironmental
NCDEQ Stormwater Design Manual Quality
shelf is not required around the perimeter of the forebay, although the designer may provide one
if it suits the project.
MDC 7: DRAWDOWN TIME.
The design volume shall draw down to the permanent pool level between two and five days.
The design volume shall be retained for two to five days; however, this requirement does not
apply to any peak attenuation volume that the pond is designed to handle. However, the
hydraulics of any peak flow attenuation capacities should be considered when calculating the
two to five-day drawdown rate.
MDC 8: PROTECTION OF THE RECEIVING STREAM.
The wet pond shall discharge the runoff from the one-year, 24-hour storm in a manner that
minimizes hydrologic impacts to the receiving channel.
Eventually, there will be more technical information available on this MDC. For now, it is being
researched at NCSU.
MDC 9: FOUNTAINS.
If fountains are proposed, then documentation shall be provided that they will not resuspend
sediment or cause erosion in the pond.
Fountains are optional, decorative wet pond Figure 6: Fountain in a Wet Pond
amenities. DEQ advises that fountains be ;.' �
designed as follows: `' .. '
1. The fountain should draw water from fewer
than two feet below the permanent pool to �` . r
avoid resuspending solids. 11:'-*'
2. Separated units (where the nozzle, pump : , `' fi
and intake are connected by tubing) should k '4* ,.
be used only if they draw water from the =r ;
surface in the deepest part of the pond. �►-
3. The falling water from the fountain should .ww
be centered in the pond, away from the
shoreline. -
MDC 10: TRASH RACK.
A trash rack or other device shall be provided to prevent large debris from entering the outlet
system.
See Chapter A-5 for more information on trash racks and other devices that may be used to
prevent large debris from entering the outlet system.
C-3. Wet Pond 11 Revised: 11-23-2020

0 Environmental
NCDEQ Stormwater Design Manual Qaaliry
MDC 11: VEGETATION.
The following criteria apply to vegetation in and around the wet pond:
(a) The dam structure, including front and back embankment slopes, of the pond shall be
vegetated with non-clumping turf grass; trees and woody shrubs shall not be allowed;
and
(b) The vegetated shelf shall be planted with a minimum of three diverse species of
herbaceous, native vegetation at a minimum density of 50 plants per 200 square feet of
shelf area.
The wet pond design should include a landscape plan that has been prepared by a qualified
design professional licensed in North Carolina. The landscape plan should provide
specifications for the vegetation species, installation, and the post-installation care. The
landscape plan shall cover the dam, embankment slopes and the vegetated shelf.
On the dam and the dam and embankment slopes, turf grass provides stability and enhances
access to the facility for maintenance. DEQ recommends perennial grasses such as hybrid
Bermuda or centipede in the Coastal Plan and Piedmont, and cool season turf grass such as
fescue and bluegrass in the Mountains. Weeping love grass is not allowed because it does not
provide long-term slope stabilization.
Trees and woody shrubs shall not be planted on the dam or embankment slopes and any
volunteers should be removed as part of regular maintenance actives. However, trees and
shrubs may be planted outside of the embankment slopes and can serve to shade the wet
pond, along its south, east, and west sides. Shading reduces heating of the water and helps to
reduce algal blooms and the potential for anaerobic conditions.
Figure 7: Vegetated Shelf(University of Idaho)
= ,_,
. ..,f...,:•,.:,,,f,:_., 4,gerp. -. ,:s, 'i. ' iPm0 yik Air ,li , -. .,,,,,„„--- -
„;..,. ,„:.)' •-,,s•,„• 0 .
t *' f.,t i y,
l{
l P .r
~� ' ai f, � • }� f
;r it 41': aA Pee
F' ; •.
Nytit,
o ae-, -
t t ,.> .„
'
The plants on the vegetated shelf are important to discourage waterfowl (a source of nutrients
and bacteria directly to the wet pond) and protect the shoreline from erosion. Vegetated
shelves also enhance safety by discouraging children from entering the pond. The designer
should design for the hydrologic conditions of the vegetated shelf. Table 3 below lists plants for
vegetated shelves that will remain submerged and partially submerged between storm events.
If the vegetated shelf will be above the permanent pool and/or the permanent pool drops
C-3. Wet Pond 12 Revised: 11-23-2020

Environmental
NCDEQ Stormwater Design Manual Quality
between storm events due to infiltration, plants that are adapted to drier conditions should be
specified. Wetland seed mixes shall not be used.
Table 3: Plants for Submerged and Partially Submerged Vegetated Shelves
Botanical Name Common Name
Asclepias incarnata Swamp Milkweed
Carex tenera Quill sedge
Chelone glabra White Turtlehead
Eupatoriadelphus dubius Dwarf Joe Pye Weed
Eupatoriadelphus fistulosus Joe Pye Weed
Eupatoriadelphus maculatus Spotted trumpetweed
Hibiscus coccineus Scarlet rose mallow
Hibiscus laevis Halberdleaf rosemallow
Kosteletzkya virginica Seashore Mallow
Lobelia cardinalis Cardinal flower
Lobelia elongata Longleaf lobelia
Lobelia siphilitica Great blue Lobelia
Rhynchospora colorata Starrush whitetop
Saccharum baldwinii Narrow plumegrass
C-3. Wet Pond 13 Revised: 11-23-2020

Environmental
NCDEQ Stormwater Design Manual Qaaliry
Recommendations
RECOMMENDATION 1: OUTLET STRUCTURE.
The following recommendations apply to the outlet structure:
(a) A drawdown orifice should have a turned-down elbow in order to prevent trash or other
material floating on the surface from clogging the pipe.
(b) The riser should be placed close to the embankment to facilitate maintenance and reduce
flotation forces.
(c) The design engineer should calculate flotation force for any outlet design subject to
flotation forces.
(d) Measures should be provided along the barrel of the principal spillway to prevent piping.
(e) Durable materials, such as reinforced concrete, are preferable to corrugated metal in
most instances. The riser should be placed in or at the face of the embankment such that
maintenance access is facilitated and flotation forces are reduced.
In addition to achieving the 2 to 5-day drawdown period, outlets should be designed for ease of
maintenance. One possible configuration option of the outlet piping that simplifies maintenance
and reduces the potential for obstruction is the submerged orifice arrangement shown in Figure
3 at the beginning of this chapter.
Durable materials, such as reinforced concrete, are preferable to corrugated metal in most
instances. The riser should be placed in or at the face of the embankment. By placing the riser
close to the embankment, maintenance access is facilitated and flotation forces are reduced.
The design engineer must present flotation force calculations for any outlet design subject to
flotation forces. See Chapter A-5 for more information about designing outlet structures.
RECOMMENDATION 2: EMERGENCY SPILLWAY.
It is strongly recommended to provide an emergency spillway to prevent structure failure of
the embankment structure during large storm events.
Emergency overflow spillways should be designed with hardened materials to prevent structural
failures, which are expensive to repair and can pose safety risks for persons and property
downslope of the wet pond.
RECOMMENDATION 3: IRRIGATION.
Irrigation is allowed but the designer should maintain some water in the permanent pool,
specify appropriate plants for the vegetated shelf, and consider human health issues.
Irrigation from wet ponds is allowed. Irrigation from a pond will help the site better match pre-
development hydrology by soaking surface runoff into the ground between storms. It will also
increase the storage capacity in the pond for the next storm. Drawdown should not eliminate
the permanent pool since the settling accomplished in the pool is a vital mechanism for pollutant
removal. Also, plant species that are drought-hardy should be selected for the vegetated shelf.
The owner should be aware of potential health issues with spraying water stored in a wet pond.
Algal growth and the associated cyanobacteria produce toxins that may be released in an
C-3. Wet Pond 14 Revised: 11-23-2020

NZ Environmental
NCDEQ Stormwater Design Manual Qaaliry
aerosol form. There is a documented case where irrigation spray from an algae-laden wet pond
caused several citizens to become ill. Although there does not seem to be evidence of such
adverse effects occurring in North Carolina, a property owner should be cognizant of the
potential liability from such a situation. Improperly treated stormwater can contain other types of
harmful bacteria that, when placed in human skin contact, could be a health issue.
As with all irrigation, caution should be taken to make sure that spray does not occur on lands
that would result in surface runoff to streams or erosion on bare areas.
RECOMMENDATION 4: SAFETY.
Engineering design features that encourage safety are recommended.
The permanent pool of water presents an attractive play area to children and thus may create
safety problems. Engineering design features that discourage child access are recommended.
Trash racks and other debris-control structures should be sized to prevent entry by children.
Other safety considerations include using fences around the spillway structure, embankment,
and wet pond slopes; using shallow safety benches around the wet pond; and posting warning
signs.
Fencing of wet ponds is not generally aesthetically pleasing but may be required by the local
review authority. Another method is to engineer the contours of the wet pond to eliminate steep
drop offs. Riser openings should not permit unauthorized access. End walls should be fenced
to prevent falls if they are a sufficient height to cause a safety concern.
RECOMMENDATION 5: TEMPERATURE CONTROL.
The follow recommendations pertain to reducing the warming of stormwater in a wet pond:
(f) Trees and shrubs can be planted to maximize pond shading, primarily along the south,
east, and west sides of the basin to reduce temperature impacts.
(g) The outlet structure can be modified to withdraw from a deeper point in the permanent
pool to reduce temperature impacts.
These recommendations should be considered in trout waters; however, they are helpful to
protecting all streams throughout North Carolina. Outlet structures designed to withdraw water
from deeper in the wet ponds should be designed sufficiently above the bottom of the wet pond
to prevent the withdrawal of sediment from the pond.
Design Variants
DESIGN VARIANT 1: FLOATING WETLAND ISLAND (FWI).
FWIs may be added as an optional enhancement to wet ponds to increase their
effectiveness at removing nutrients. The additional nutrient credits are described in the SCM
Credit Document.
FWIs should adhere to the following MDC or an alternative design with equal or greater
effectiveness:
C-3. Wet Pond 15 Revised: 11-23-2020

Fni mtal
NCDEQ Stormwater Design Manual
(a) The maximum depth for the wet pond shall be 6 feet to ensure that the stormwater is in
contact with the roots of the wetland plants.
(b) Wetland mat material shall float, be durable, non-toxic, and capable of supporting plant
life, allowing root growth freely through the bottom into the water column.
(c) Floating mats shall be spaced evenly from bank to bank perpendicular to the flow.
Floating mats shall be at least 10 feet away from the outlet structure to prevent clogging.
(d) Vegetation shall be obligate wetland plants that are capable of developing thick root
masses that hang two to three feet in the water column for optimal water interception.
(e) Plants shall be installed at a density of one plant per 2 square feet. There shall be a
minimum of 85% aerial coverage of plants on the mats.
(f) Anchor cable shall be as long as the maximum depth of the pond. Stainless steel or
durable plastic cables are recommended for connecting the FTW to a weighted anchor
such as cinderblocks at the bottom of the pond). The anchor cable should be inspected
annually.
(g) Prior to installing FWIs, the wet pond should be inspected for invasive aquatic weeds so
they can be removed. Planting material should be peat moss or potting soil (per
manufacturer's recommendations) installed in pre-drilled holes in the floating mat
material.
(h) Fencing should be should be initially be installed over the island to prevent geese &
wildlife intrusion while plants are being established. Twine or deer fencing is
recommended.
Maintenance
Important operation and maintenance procedures:
1. Immediately after the wet pond is established, the plants on the vegetated shelf and
perimeter of the basin will be watered twice weekly if needed, until the plants become
established (commonly six weeks).
2. No portion of the wet pond will be fertilized after the first initial fertilization that is required
to establish the plants on the vegetated shelf.
3. Stable groundcover will be maintained in the drainage area to reduce the sediment load
to the wet pond.
4. If the pond must be drained for an emergency or to perform maintenance, the flushing of
sediment through the emergency drain will be minimized as much as possible.
5. Once a year, a dam safety expert should inspect the embankment.
6. The measuring device used to determine the sediment elevation shall be such that it will
give an accurate depth reading and not readily penetrate into accumulated sediments.
C-3. Wet Pond 16 Revised: 11-23-2020

IC ni minf
NCDEQ Stormwater Design Manual "
After the wet pond is established, it should be inspected quarterly and within 24 hours after
every storm event greater than 1.0 inches (or 1.5 inches if in a Coastal County).. Records
of operation and maintenance will be kept in a known set location and shall be available upon
request.
Inspection activities shall be performed as follows. Any problems that are found shall be
repaired immediately.
Table 4: Sample Operation and Maintenance Provisions for Wet Ponds
SCM element: Potential problems: How to ediate the
prooblblem:
The entire SCM Trash/debris is present. Remove the trash/debris.
Regrade the soil if necessary to
Areas of bare soil and/or remove the gully, plant ground
The perimeter of the wet pond erosive gullies have formed. cover and water until it is
established. Provide lime and
a one-time fertilizer application.
Unclog the pipe. Dispose of
The inlet pipe is clogged (if the sediment in a location
applicable). where it will not cause impacts
to streams or the SCM.
The inlet pipe is cracked or
The inlet device otherwise damaged (if Repair or replace the pipe.
applicable).
Regrade the swale if necessary
Erosion is occurring in the and provide erosion control
swale (if applicable). devices such as reinforced turf
matting or riprap to avoid future
erosion problems.
Search for the source of the
Sediment has accumulated to a sediment and remedy the
depth greater than the original problem if possible. Remove
design depth for sediment the sediment and dispose of it
storage. in a location where it will not
cause impacts to streams or
The forebay the SCM.
Provide additional erosion
protection such as reinforced
Erosion has occurred. turf matting or riprap if needed
to prevent future erosion
problems.
C-3. Wet Pond 17 Revised: 11-23-2020

ItZ t, mtof
NCDEQ Stormwater Design Manual "`;;"'
Remove the weeds, preferably
Weeds are present. by hand. If pesticide is used,
wipe it on the plants rather than
spraying.
Best professional practices Prune according to best
show that pruning is needed to professional practices.
maintain optimal plant health.
Determine the source of the
problem: soils, hydrology,
disease, etc. Remedy the
Plants are dead, diseased or problem and replace plants.
The vegetated shelf dying. Provide a one-time fertilizer
application to establish the
ground cover if a soil test
indicates it is necessary.
Remove the weeds, preferably
Weeds are present. by hand. If pesticide is used,
wipe it on the plants rather than
spraying.
Search for the source of the
sediment and remedy the
Sediment has accumulated to a problem if possible. Remove
depth greater than the original the sediment and dispose of it
design sediment storage depth. in a location where it will not
cause impacts to streams or
the SCM.
The main treatment area
Algal growth covers over 50% Consult a professional to
of the area. remove and control the algal
growth.
Cattails, phragmites or other Remove the plants by wiping
invasive plants cover 50% of them with pesticide (do not
the basin surface. spray).
Shrubs have started to grow on Remove shrubs immediately.
the embankment.
Evidence of muskrat or beaver Consult a professional to
The embankment activity is present. remove muskrats or beavers
and repair any holes or erosion.
A tree has started to grow on Consult a dam safety specialist
the embankment. to remove the tree.
C-3. Wet Pond 18 Revised: 11-23-2020

Environmental
NCDEQ Stormwater Design Manual Quality
An annual inspection by an
appropriate professional shows Make all needed repairs
that the embankment needs immediately.
repair.
Clean out the outlet device and
Clogging has occurred. dispose of any sediment in a
gg g location where it will not cause
The outlet device impacts to streams or the SCM
The outlet device is damaged Repair or replace the outlet
device.
Weeds or volunteer trees are Remove the weeds or trees.
growing on the mat.
Floating wetland island (if
applicable)
The anchor cable is damaged, Restore the anchor cable to its
disconnected or missing. design state.
Erosion or other signs of Repair the damage and
damage have occurred at the improve the flow dissipation
outlet. structure
The receiving water
Discharges from the wet pond
are causing erosion or Contact the local NCDEQ
sedimentation in the receiving Regional Office.
water.
https://www.bae.ncsu.ed u/extension/ext-publications/water/protecti nq/sea-q rant-stormwater-
ponds-factsheet.pdf
Old Versus New Design Standards
The following is a summary of some of the changes in wet pond design standards between the
archived version of the BMP Manual and the current MDC for wet ponds. It is intended to
capture the highlights only; any wet pond MDC that are not captured in this table are still
required per 15A NCAC 02H .1053.
Old manual requirements New MDC
Drawdown time for the 2-5 days 2-5 days
design volume
Sizing SA/DA tables SA/DA tables or HRT method
(designer's choice)
Vegetated shelf min width 10 feet 6 feet
C-3. Wet Pond 19 Revised: 11-23-2020

Eni mtol
NCDEQ Stormwater Design Manual "`1;"'
Vegetated shelf max 10:1 6:1
slope
Vegetated shelf location Halfway above and halfway below Flexible; can be entirely above or
the permanent pool entirely beneath the permanent pool
or partway; vegetated shelf plants
should be adjusted accordingly
SHWT requirements Permanent pool shall be within 6" No requirements regarding SHWT
of the SHWT(either above or
below)or a liner shall be provided
LS-FS downslope of pond Required Not required
90% TSS pond design Allowed to stand alone as an No longer relevant, SA/DA Tables
alternative to providing an 85% are for the 85% pond. Also, SA/DA
pond with a LS-FS Tables pertain to sizing the main
pool, with the forebay added later;
that is why the values are 15%
lower.
Minimum length to width 1.5:1 with 3:1 recommended Specific ratio not given; instead,
ratio inlet(s)and outlet shall be located to
avoid short circuiting.
Forebay size Forebay required to be 20% of Forebay required to be 15-20% of
the overall wet pond volume main pool volume
Forebay design Not specified Forebay should be deeper at the
entrance, shallower at the exit.
Fountains Table limiting pump power Fountains allowed as long as they do
according to pond volume not resuspend sediment or cause
erosion around the perimeter of the
pond.
Trash rack Not required Trash rack or other device to exclude
trash from the outlet structure
required.
C-3. Wet Pond 20 Revised: 11-23-2020

Harnett County Solid Waste Department I Stormwater Permit Application—October 2024
E.3
E
3
II
Attachment E.3 — Wet
Pond Operation and
Maintenance Agreement

Harnett County Solid Waste Department I Stormwater Permit Application—October 2024 1.)1
Attachment E.3—Wet Pond Operation and Maintenance Agreement
This page intentionally left blank.

Operation & Maintenance Agreement
Project Name: Harnett County Northwest Convenience Center
Project Location: 1971 Oakridge River Road, Fuquay-Varina, NC 27526
Cover Page
Maintenance records shall be kept on the following SCM(s). This maintenance record shall be kept in a log in a known set location.
Any deficient SCM elements noted in the inspection will be corrected, repaired, or replaced immediately. These deficiencies can
affect the integrity of structures, safety of the public, and the pollutant removal efficiency of the SCM(s).
The SCM(s) on this project include (check all that apply&corresponding O&M sheets will be added automatically):
Infiltration Basin Quantity: Location(s):
Infiltration Trench Quantity: Location(s):
Bioretention Cell Quantity: Location(s):
Wet Pond Quantity: 1 Location(s): Western portion of site
Stormwater Wetland Quantity: Location(s):
Permeable Pavement Quantity: Location(s):
Sand Filter Quantity: Location(s):
Rainwater Harvesting Quantity: Location(s):
Green Roof Quantity: Location(s):
Level Spreader- Filter Strip Quantity: Location(s):
Proprietary System Quantity: Location(s):
Treatment Swale Quantity: Location(s):
Dry Pond Quantity: Location(s):
Disconnected Impervious Surface Present: No Location(s):
User Defined SCM Present: No Location(s):
Low Density Present: No Type:
I acknowledge and agree by my signature below that I am responsible for the performance of the maintenance procedures listed for
each SCM above, and attached O&M tables. I agree to notify NCDEQ of any problems with the system or prior to any changes to
the system or responsible party.
Responsible Party: Chad Beane
Title & Organization: Harnett County Solid Waste Director
Street address: 200 Alexander Drive
City, state, zip: Lillington, NC 27546
Phone number(s): 910-814-6004
Email: [e-mail]
Signature: Date: tO-22-ZOZs-I
EA-11 W iN1541,1 , a Notary Public for the State of it�oi Ce.YYiU'
County of 14c , do hereby certify that ,, C°.,,.lad �c3 �e-
personally appeared before me this 7 Z4`t day of C #Q " ' � -uv-t and
acknowledge the due execution of the Operations and Maintenance Agreement .
Witness *n§ icial seal, eyklik- C151- "i/ •
Nit, USA,
Seal My commission expires 03-22 2027
STORM-EZ 10/17/2024
Version 1.5 O&M Agreement Page 1 of 5

Wet Pond Maintenance Requirements
Important operation and maintenance procedures:
Immediately after the wet detention basin is established, the plants on the vegetated shelf and
- perimeter of the basin should be watered twice weekly if needed, until the plants become established
(commonly six weeks).
No portion of the wet pond should be fertilized after the initial fertilization that is required to establish
- the plants on the vegetated shelf.
_ Stable groundcover will be maintained in the drainage area to reduce the sediment load to the wet
pond.
If the pond must be drained for an emergency or to perform maintenance, the flushing of sediment
- through the emergency drain will be minimized as much as possible.
At least once annually, a dam safety expert will inspect the embankment. Any problems that are
- found will be repaired immediately.
The measuring device used to determine the sediment elevation shall be such that it will give an
accurate depth reading and not readily penetrate into accumulated sediments.
After the wet pond is established, it will be inspected quarterly and within 24 hours after every storm event greater
than 1.0 inches (or 1.5 inches if in a Coastal County). Records of operation and maintenance shall be kept in a
known set location and shall be available upon request.
Inspection activities shall be performed as follows. Any problems that are found shall be repaired immediately.
SCM element: Potential problem: How to remediate the problem:
The entire wet pond Trash/debris is present. Remove the trash/debris.
The perimeter of the wet Areas of bare soil and/or Regrade the soil if necessary to remove the gully, plant ground
pond erosive gullies have cover and water until it is established. Provide lime and a one-
formed. time fertilizer application.
The inlet pipe is clogged (if Unclog the pipe. Dispose of the sediment off-site.
applicable).
The inlet pipe is cracked or
otherwise damaged (if Repair or replace the pipe.
The inlet device applicable).
Erosion is occurring in the Regrade the swale if necessary and provide erosion control
swale (if applicable). devices such as reinforced turf matting or riprap to avoid future
problems with erosion.
Sediment has
accumulated to a depth Search for the source of the sediment and remedy the problem
greater than the original if possible. Remove the sediment and dispose of it in a location
design depth for sediment where it will not cause impacts to streams or the SCM.
storage.
The forebay
Erosion has occurred. Provide additional erosion protection such as reinforced turf
matting or riprap if needed to prevent future erosion problems.
Weeds are present. Remove the weeds, preferably by hand. If pesticide is used,
wipe it on the plants rather than spraying.
1

Wet Pond Maintenance Requirements (Continued)
SCM element: Potential problem: How to remediate the problem:
Sediment has
accumulated to a depth Search for the source of the sediment and remedy the problem
greater than the original if possible. Remove the sediment and dispose of it in a location
design sediment storage where it will not cause impacts to streams or the SCM.
depth.
The main treatment area Algal growth covers over Consult a professional to remove and control the algal growth.
50% of the area. g
Cattails, phragmites or
other invasive plants cover Remove the plants by wiping them with pesticide (do not spray).
50% of the basin surface.
Best professional practices
show that pruning is Prune according to best professional practices.
needed to maintain
optimal plant health.
The vegetated shelf Determine the source of the problem: soils, hydrology, disease,
Plants are dead, diseased etc. Remedy the problem and replace plants. Provide a one-
or dying. time fertilizer application to establish the ground cover if a soil
test indicates it is necessary.
Weeds are present. Remove the weeds, preferably by hand. If pesticide is used,
wipe it on the plants rather than spraying.
Shrubs have started to Remove shrubs immediately.
grow on the embankment.
Evidence of muskrat or Consult a professional to remove muskrats or beavers and
beaver activity is present. repair any holes or erosion.
The embankment A tree has started to grow Consult a dam safety specialist to remove the tree.
on the embankment.
An annual inspection by
an appropriate
professional shows that Make all needed repairs immediately.
the embankment needs
repair.
Clogging has occurred. Clean out the outlet device and dispose of any sediment in a
gg g location where it will not cause impacts to streams or the SCM.
The outlet device
The outlet device is Repair or replace the outlet device.
damaged.
Weeds or volunteer trees Remove the weeds or trees.
are growing on the mat.
Floating wetland island
(if applicable) The anchor cable is
damaged, disconnected or Restore the anchor cable to its design state.
missing.
1

Wet Pond Maintenance Requirements (Continued)
SCM element: Potential problem: How to remediate the problem:
Erosion or other signs of
damage have occurred at Repair the damage and improve the flow dissipation structure.
the outlet.
The receiving water Discharges from the wet
pond are causing erosion Contact the local NCDEQ Regional Office.
or sedimentation in the
receiving water.
1

Wet Detention Pond Design Summary
Wet Pond Diagram
WET POND ID FOREBAY MAIN POND
WP Permanent Pool El. 322 Permanent Pool El. 322.4
Temporary Pool El: 322 Temporary Pool El: 324.5
Pretreatment other Clean Out Depth: 1 Clean Out Depth: 3.4
than forebay? No Sediment Removal El 321 Sediment Removal El 319
Has Veg. Filter? No Bottom Elevation: 320 Bottom Elevation: 318.5
ATTACH ADDITIONAL SHEETS IF NECESSARY
1

Harnett County Solid Waste Department I Stormwater Permit Application—October 2024 1.)1
Attachment E.3—Wet Pond Operation and Maintenance Agreement
This page intentionally left blank.

Harnett County Solid Waste Department I Stormwater Permit Application—October 2024 I.)
Attachment F—Property Deed and Boundary Plan J
Attachment F — Property
Deed and Boundary Plan

Harnett County Solid Waste Department I Stormwater Permit Application—October 2024 1.)1
Attachment F—Property Deed and Boundary Plan

B3617 - P699
For Registration Kimberly S. Hargrove
Register of Deeds
Harnett County, NC
HARNETT COUNTY TAX ID # Electronically Recorded
050634 0019 03 2018 Jun 26 02:57 PM NC Rev Stamp: $ 1110.00
Book: 3617 Page:699 - 701 Fee: $ 26.00
Instrument Number: 2018009124
06-26-2018 BY: SB
NORTH CAROLINA GENERAL WARRANTY DEED
Excise Tax: $1,110.00 NO TITLE SEARCH NOR TAX ADVICE GIVEN
Parcel Identifier No. 050634 0019 03 Verified by County on the day of ,20
By:
Mail/Box to: Dwight W. Snow. Attorney at Law: P.O. Box 397. Dunn. NC 28335
This instrument was prepared by: Currie Tee Howell, Attorney. Adams. Howell. Sizemore & Lenfestey, P.A.
Brief description for the Index: 28.29 +/- acres off Oakridge River Road
THIS DEED made this 22nd day of June, 2018, by and between
GRANTOR GRANTEE
Jam my Scott Mason and wife, Sharon County of Harnett, a Political
Pearce Mason Subdivision of the State of North
Carolina
6412 Burt Road PO Box 759
Fuquay-Varina, NC 27526 Lillington, NC 27546
Enter in appropriate block for each Grantor and Grantee: name, mailing address, and, if appropriate, character of entity, e.g.
corporation or partnership.
The designation Grantor and Grantee as used herein shall include said parties, their heirs, successors, and assigns, and shall include
singular, plural, masculine, feminine or neuter as required by context.
WITNESSETH, that the Grantor, for a valuable consideration paid by the Grantee, the receipt of which is hereby acknowledged, has
and by these presents does grant, bargain, sell and convey unto the Grantee in fee simple, all that certain lot or parcel of land situated
in Buckhorn Township, Harnett County, North Carolina and more particularly described as follows:
SEE ATTACHED EXHIBIT "A"
If checked, this property is the principal residence of the Grantor.
NC Bar Association Form No. 3© 1976, Revised© 1/1/2010
Pri nteri by A oreement with the NC Rar A ccnri atinn
Submitted electronically by "Dwight Snow Attorney at Law"
in compliance with North Carolina statutes governing recordable documents
and the terms of the submitter agreement with the Harnett County Register of Deeds .

B3617 - P700
The property hereinabove described was acquired by Grantor by instrument recorded in Book 1164, Book 584 and Book 1 328 Page
8.
A map showing the above described property is recorded in Plat Cabinet F, Slide 588-A (Tract One) and Map Book 99, Page 24
(Tract Two), Harnett County Registry.
TO HAVE AND TO HOLD the aforesaid lot or parcel of land and all privileges and appurtenances thereto belonging to the Grantee
in fee simple.
And the Grantor covenants with the Grantee, that Grantor is seized of the premises in fee simple, has the right to convey
the same in fee simple, that title is marketable and free and clear of all encumbrances, and that Grantor will warrant and
defend the title against the lawful claims of all persons whomsoever, other than the following exceptions:
This conveyance is expressly made subject to the lien created by all the Grantors' real 2018 Harnett County ad valorem
taxes on said tract of land which the Grantee(s) agree to assume and pay in full when due.
Subject to all easements, rights-of-way, covenants and other restrictions as shown on the public record or as would be
disclosed by an accurate survey and inspection of the land.
IN WITNESS WHEREOF, the Grantor has duly executed the foregoing as of the day and year first above written.
Grantor(s):
e•-1 6 SEAL)
Jam Scott Mason
v%.k c2CkL WL(
�AL� `
Sharon Pearce Mason
State of - County or City of
I, the undersigned Notary Public of the County or City of Q.. and State aforesaid, certify that Jammy Scott
Mason and wife, Sharon Pearce Mason,personally appeared before me this day and acknowledged the due execution of the foregoing
instrument for the purposes therein expressed. Witness my hand and Notarial stamp or seal thisa6_ day of June, 2018.
11 ��t�4 »ti= „riirji.,�
` A�/
My Commission Expires: � 1 _.�``� ' I 1 1 °
/4 ' (IA_
�i, , . �l! �tA , Notary Public
(Affix Seal) k' - Nota .' . Printed i r Typed Name
�
yily� immn�1��'����
rr� s r Co My ,
s SSfON XPIAes m
s
. %
-7 Ug LIG G`��r.
CO U Kral 01.
/NANDII anMt''
NC Bar Association Form No. 3 © 1976,Revised© 1/1/2010
Printed by Agreement with the NC Bar Association

B3617 - P701
EXHIBIT "A"
TRACT ONE:
BEING all of that tract of land containing 13.84 acres, 0.56 acre of which lies within the road right
of way of Oakridge River Road (S.R. 1418), as is shown on the plat entitled "Boundary Survey for
Jammy Scott Mason & Sharon Pearce Mason" dated May 29, 1996 and revised on June 11, 1996
which appears of record in Plat Cabinet F, Slide 588-A, Harnett County Registry, to which reference
is hereby made for a more definite and precise description.
By deed recorded in Book 650, Page 758, Harnett County Registry from Revels Tractor Company,
Inc., Charles T. Revels received a one-half undivided interest, Bobby 3. Revels received a one-fourth
undivided interest and William A. Hipp received a one-fourth undivided interest in the above
described property.
TRACT TWO:
BEGINNING at an iron pipe set in the southern boundary line of the 13.85 acre tract of property
previously conveyed to Grantees by deed recorded in Book 1164, Pages 584-586, Harnett County
Registry, said beginning point being North 60° 49' 37" West 344.10 ft. from the point where the
southeastern corner of said 13.85 acre tract lies at the western margin of Oakridge River Road (S.
R. 1418); thence along and with the southern boundary of said tract North 60°49' 37" West 207.85
ft. to an existing iron pipe (at edge of field/pine forest); thence continuing with said southern line
North 60°49'37" West 334.62 ft.to an existing iron pipe;thence with the western line of such 13.85
acre tract North 06° 28' 15" East 331.81 ft. to an existing iron pipe (control corner); thence a new
line North 85° 02' 16" West 431.10 ft.to an iron pipe set,a corner in the line of the property owned
now or formerly by Lawrence Wells and Vada S. Wells described by deed recorded in Book 319,
Page 421, ,Harnett County Registry; thence a new dividing line South 05° 00' 00" West 1011.00 ft.
to an iron pipe set; thence as another new dividing line South 87° 40' 46" East 459.76 ft to an iron
pipe set; thence South 79° 20' 36" East 111.80 ft. to an iron pipe set; thence North 83° 3 0' 46" East
43.56 ft.to anironpipe set;thence North 68° 59'41" East 138.37 ft.to an iron pipe set; thence North
40°46' 46" East 173.13 ft.to an iron pipes,t; thence North 05°28' 55"East 33.66 ft. to an iron pipe
set;thence North 26° 04' 27" East 21 S.14 ft. to the point and place of BEGNNING, and being all
of that parcel of property containing 15.00 acres, more or less, as shown on the survey entitled
"Recombination Survey for Jammy Scott Mason and Sharon Pearce Mason" filed for record as Map
#99-24, in.the Harnett County,North Carolina, Registry.
By deed recorded in Book 650, Page 758,Harnett County Registry from Revels Tractor Company,
Inc.,Charles T.Revels received a one-half undivided interest,Bobby J.Revels received a one-fourth
undivided interest and William A. Hipp received a one-fourth undivided interest in the above
described property.

Harnett County Solid Waste Department I Stormwater Permit Application-May 2024 En
Attachment F-Property Deed and Boundary Plan

B2019 - P 142
LEGEND Duncan NC 42
fi
CMS - CONCRETE MONUMENT SET ECS - EXISTING COTTON SPINDLE NE. 1116------...s..&,/,
ECM - EXISTING CONCRETE MONUMENT CSS - COTTON SPINDLE SET
EIP - EXISTING IRON PIPE D - DRAINAGE M
co
EIS - EXISTING IRON STAKE G - GAS LINE NCSR 140'
En - EXISTING REBAR S - SANITARY SEWER k1.
ECS - EXISTING COTTON SPIKE W -
WATER
EPK - EXISTING PK NAIL E - ELECTRIC 0 Gc'�
EN - EXISSINN NNL BETTY WELLS TILLEY TRUST c� a
ERS - EXISTING RAILROAD SPIKE T- TELEPHONE ry
IPS - IRON PIPE SET FH - FIRE HYDRANT D.B. 2954 PG. 618 v
ISS - IRON STAKE SET WM - WATER METER z SITE
RSS - RAILROAD SPIKE SET 3 itNS NAIL SET WV- WATER VALVE 2
PKS - PK OR MAG. NAIL SET CO - SEWER CLEANOUT EIP
R/W - RIGHT OF WAY TP - TELEPHONE PEDESTAL
CL - CENTERUNE UP - UTILITY POLE u \
B.M. - BOOK OF MAPS EL - ELEVATION
P.B. - PLAT BOOK MH - MANHOLE c'j S A. •50'18"E INTERSECTION VICINITY MAP (no scale)
M.B. - MAP BOOK BC - BACK OF CURB co
D.B. - DEED BOOK HVAC - HEAT/AC UNIT .) 9 TIE 1 Nc�'
SB - SET BACK CP - COMPUTED POINT cV co 877.42' 07 42' S 10'36'36°W I fl�i r'C��
N�CGS EDGE PAVEMENT
CAROUNA GEODETIC SURVEY . 0 32.86' ,ECS 6�'p s �„,� '
OHW-OVERHEAD WIRES 0 N \/C AD
Z EIP } .ECS R/wR/w
NOTES EIP EIP
GRID
TP'"1 04
S 86'35'42"E
AREA BY COORDINATES. 430.95' EIP COORDINATES o R
THIS PROPERTY IS NOT LOCATED IN A FEMA MAPPED N - 645,027.663 to /h
FLOOD HAZARD AREA. FEMA MAP # EIP NC GRID E - 2,035,894.990
ZONE X; EFF. DATE 10/3/2006. COORDINATES ELEV. - 367.727
SUBJECT TO ABOVE AND OR UNDERGROUND N - 644,963.235 3
UTILITIES AND OR EASEMENTS. E - 2,03,0159731 .' ico
NO TITLE SEARCH WAS PROVIDED TO THE SURVEYOR. io C4
NC GRID COORDINATES FROM GPS-VRS O orn
OBSERVATIONS. NAD 83(2012B) ELEVATIONS NAVD 88 N •to 'V, �"�
GPS UNIT - SPECTRA PRECISION SP-80. ) 00 CD 1 T-t C_
0 i IZ-9
REFERENCES
D.B. 3617 PG. 699 a w CO
MAP # 99-24 Cam) C./
a
MAP # 2007-427 I O
D.B. 646 PAGE 582
OTHERS AS SHOWN I cp
O
EIP-NAIL EIP
NC GRID
COORDINATES
28.263 ACRES
_ N - 644,635.130 \
FOR REGISTRATION _° TO ROAD R/W EL- 2,0 3,835.190 \
Kimberly S. Hargrove
REGISTER OF DEEDS °'Nt, W \
Harnett County, NC v-CO C " 3 I \
2019 MAY 07 04:2 :54 PM n
BK:2019 PG:142-142 way CIO I \ CALLS ALONG ROAD R/W
FEE:$21.00
INSTRUMENT # 2019005924 ct�N N po z. COURSE BEARING DISTANCE
T LIES TER -I N. M g
La . . O M p L-1 S 10'17'30"W 80.90'
IL
11
zma z N L-2 S 13'44'33'W 23.00'
III II Qom II
2019005924
EIP
O6,(0 N 6344.7 GRAVEL L-1 EIP / \
�, O 22 7' DRiVE_-
ry `?48'� L—\2 TP, /-
EIP
I, BENTON W. DEWAR, PROFESSIONAL LAND SURVEYOR �,
NO. L-3040, CERTIFY: Ui
THAT THE SURVEY IS OF AN EXISTING PARCEL OR PARCELS OF LAND EIP UP
OR ONE OR MORE EXISTING EASEMENTS AND DOES NOT CREATE EIP m
A NEW STREET OR CHANGE AN EXISTING STREET. S 03'53'27"W 02
FOR THE PURPOSES OF THIS SUBSECTION, AN "EXISTING PARCEL" EIP 33.70' 3
OR "EXISTING EASEMENT" IS AN AREA OF LAND DESCRIBED
IN A SINGLE, LEGAL DESCRIPTION OF LEGALLY RECORDED \ a ,,
SUBDIVISION THAT HAS BEEN OR MAY BE LEGALLY CONVEYED 1 O \\ B D.B. &36 3 TERRI HO G. WELL BOUNDARY SURVEY FOR THE
TO A NEW OWNER BY DEED IN IT'S EXISTING CONFIGURATION. ^^�0�,� ft
\\
COUNTY OF HARNETT
BENTON W. DEWAR NCPLS 3040 EIP c9 P.O. BOX 759 LILLINGTON, NC 27546
REVIEW OFFICER'S CERTIFICATE 459.69' 1�$31\9.4
EIP DEED BOOK 3617 PAGE 699
STATE OF NOR CAROU EIP N 89'15'15"W 111,90'EIP EIP 61.26
co ors 2 N $0.49'35,w 5 PIN # 0634-54-0565.000
I, .(ICI • N. REVIEW OFFICER OF f �-rY1,4 L COUNTY, CERTIFY t S 81'46'20"W BUCKHORN TOWNSHIP
THAT THE MAP 0 PLAT TO WHICH THIS CERTIFICATION 43.60'
IS 1FFlXE MEETS REQUIREMENTS FOR RECORDING.
)5 11.1.1 NJ k.ET HARNETT COUNTY — NORTH CAROLINA
(. ANNIE L. REVELS, et al SCALE : 1" = 120' — APRIL 30, 2019
REVIEW CC I"I __,,,,,,,,,, D.B. 2788 PG. 625
r''T CAR MAP # 2007-427 120 0 120 240 360
DATE `'�`Q.N ...'4/•
O •FESSI it v ';
I, BENTON W. DEWAR, CERTIFY THAT THIS PLAT WAS DRAWN UNDER a 9''•
MY SUPERVISION FROM AN ACTUAL SURVEY MADE UNDER MY 2 GRAPHIC SCALE - FEET
SUPERVISION DEED BOOK 3vI3 PAGE (o4Q MAP # 2+0ut PAGE 42* ; _ E SEAL 1 = HARNETT COUNTY
THAT THE BOUNDARIES NOT SURVEYED ARE CLEARLY INDICATED AS DRAWN = ' L.3040
FROM INFORMATION FOUND IN DEED MAP BOOK — PAGE < Q': L NORTH CAROIINA /� ,, II
THAT THE RATIO OF PRECISION OR POSITIONAL ACCURACY AS CALCULATED IS m'9ti �'Q : FILED DATE rJ I-1 I Q TIME `4'ZZ illl I:1goD0 F ; THAT THIS PLAT WAS PREPARED IN ACCORDANCE -F�''4 SUR`I"a Q: BENTON W. DEWAR AND ASSOCIATES
WITH G.S. 47-30 AS AM MENDED. WITNESS MY ORIGINAL SIG ATRUE, rON W.0;``` MAP NUMBER �6 - 1 PROFESSIONAL LAND SURVEYOR
'''in ,,,,
LICENSE NUMBER AND S THIS ° DAY OF r�tA A.D. 201 Y S. ARG VE 5920 HONEYCUTT ROAD
REGIST ,..0 -.) D HOLLY SPRINGS, NC 27540
c-6e-- e/ /i{ BY : •
DEPUTY 51,t),(r' PH. # (919)-552-9813
BENTON W. DEWAR, PLS - 3040
RECORDED MAP # 2019 - 1 _ 19-41L
HARNEI( COUNTY R.O.D. HARMASON\14A\600

Harnett County Solid Waste Department I Stormwater Permit Application-May 2024 En
Attachment F-Property Deed and Boundary Plan

Harnett County Solid Waste Department I Stormwater Permit Application—May 2024 r)�
Attachment F—Property Deed and Boundary Plan
1 )�
HDR Engineering, Inc. of the Carolinas
555 Fayetteville Street, Suite 900
Raleigh, NC 27601-3034
919.232.6600
NC License F0116
hdrinc.com
© 2024 HDR, Inc., all rights reserved