20231000 Ver 1_00 DEP Cary Triangle STORMWATER CALCS to ToC 070523_20230713

STORMWATER CALCULATIONS
DUKE ENERGY PROGRESS
CARY TRIANGLE EXPRESSWAY 230KV GREENFIELD SUBSTATION
DEVELOPMENT PLAN
Town of Cary Review
Last Revised 7/5/23
ACE JN: 22-035
O'`
ID
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0 0 0 0
CONSULTING ENGINEERS, PA
CIVIL, MUNICIPAL & STRUCTURAL ENGINEERS
COMPREHENSIVE ENVIRONMENTAL SERVICES
P.O. Box 7966 • Rocky Mount, NC 27804
Phone: [phone]
Fax: [phone]
www.appianengineers.com

Duke Energy Progress
STORMWATER MANAGEMENT SUMMARY
DEP CARY TRIANGLE EXPRESSWAY 230KV GREENFIELD SUBSTATION
DEVELOPMENT PLAN
Town of Cary Review
Last Revised 715123
INTRODUCTION III
On March 31, 2023, NCDEQ provided a Letter of Approval for 2.5 acres of land disturbance for clearing
of 30 ft wide paths through the wooded site for geotechnical drill rig access (WAKE-2023-059). The
Town of Cary approved the Vegetation Protection Plans for that project on April 19, 2023 (23-REVEG-
5814). No impervious surfaces were proposed for that project.
The purpose of this project is the construction of a new 230kV electrical substation owned and operated
by Duke Energy Progress (DEP) located on 37.3 acres in Cary. These plans are for work associated with
site grading, 1800 LF driveway, creek crossings, and substation pad construction (electrical lines,
structures, lighting, and substation work will be by DEP). No manned structures, water or sewer lines
are proposed. Approximately 14.0 acres will be disturbed (see Erosion Control Plan for exact area
disturbed). No permanent stormwater control measures are required for this project.
SITE INFORMATION:
LOCATION INFORMATION
Address:
3150 Green Level Road West
Town:
Cary
County:
Wake
State:
NC
Tract Acreage:
37.30 ac
Cary Zoning Classification:
R-40/R8CU
Latitude/ Longitude:
35.788953,-78.888994
STORMWATER PERMIT INFORMATION
River Basin:
Cape Fear
Watershed:
Jordan Lake (Lower New Hope)
Receiving Stream Name
Unnamed tributary to Bachelor Creek
Stream Classification:
WS-IV;NSW
,stream Index Number:
16-41-6-2-(2)
Stormwater permitting by:
Town of Cary
Appian Consulting Engineers, PA

Duke Energy Progress
NARRATIVE:
A. OWNERSHIP: All work is in within property owned by Duke Energy Progress.
B. FLOODPLAIN: The site is NOT located within a special flood hazard area per FEMA Map
3720.0734.00K, dated 7/19/22.
C. WETLANDS/STREAMS/BUFFERS: The Town of Cary has jurisdiction for riparian buffers, while the
COE and NCDEQ has jurisdiction of the wetlands and streams. Wetlands delineation shown
provided by Duke Energy Progress, prepared by AECOM, 12/16/22, has been verified by the COE per
SAW-2022-02375, 12/23/22. Buffer Impacts were approved by the Town of Cary per TCBA-22-011,
11/16/22 and TCBA-23-002, 4/4/23. COE/DEQ approval of wetlands and streams impact
forthcoming.
D. SOILS: Per hand auger borings performed by S&ME on 9/23/22, the soils at the site vary from silty
clayey sand to sandy lean clay.
As shown on the Pre -Development Conditions exhibits, the 37.30 acre site is mostly wooded except for
the grassed 70 ft wide DEP transmission corridor and areas of existing grass and shrubs. No qualifying
champion trees were found (see tree assessment surveys dated September 2022 and March 21, 2023).
Three unnamed tributaries of Bachelor Creek traverse the property and will require large culverts for
the proposed driveway.
Proposed development consists of an 1,800± LF gravel driveway and stone substation pad for electrical
equipment.
1. A small grassed area in front of the substation will be reinforced with permanent geoweb to
provide stabilization for fire trucks and maintain porosity.
2. To provide enhanced screening from adjacent properties while allowing the proposed
earthwork during construction, reforestation areas are proposed that will receive plantings
upon completion of construction. See specifications and guarantee on landscaping plan.
3. Consistent with NCDEQ Stormwater Design Manual (Section A-4), the Town of Cary considers
stone within the fenced yard of the proposed electrical substation to be pervious.
4. 4" of #57 stone over geotextile is proposed outside the substation fence on three (3) sides of the
substation as shown on the grading plan (Cross Section 104). Per the Design Manual (A-4), this
is also considered pervious.
Appian Consulting Engineers, PA

Duke Energy Progress
Proposed development at this site is regulated by:
1. Watershed Protection (LDO 4.4.6)
2. Nutrient Reduction (LDO 7.3.2)
3. Peak Runoff Control (LDO 7.3.3)
I. WATERSHED PROTECTION _A
Proposed development at this site is regulated by Watershed Protection Requirements (LDO 4.4.6), for
the Jordan Lake Watershed (non -Critical Area). The total amount of proposed impervious surfaces is
less than 24%, so this project meets the Jordan Lake Low Density Development Criteria.
Total Area of Development (Parcel): 37.30 ac
Total Impervious Area Proposed: 1.15 ac
Proposed Impervious Area: 3.09%
11. NUTRIENT •
Proposed development at this site is regulated by Nutrient Reduction requirements (LDO 7.3.2).
Nutrient loading calculations were determined using the most current, approved accounting tool by the
NC Division of Energy, Mineral, and Land Resources (NC DEMLR), which is the Stormwater Nitrogen and
Phosphorous (SNAP) v4.2.0. Results are shown on the attached SNAP document and Town of Cary
Jordan Lake Supplemental Reporting Form for Nitrogen and Phosphorous. Based on the attached
calculations, no additional measures or buy -down is needed to meet nutrient reduction requirements.
Total Nitrogen Total Phosp orus
POST -DEVELOPMENT: 54.4 18.4
Target Export Rate: 164.1 29.1
LJ
Per LDO 7.3.3, there shall be no net increase in peak stormwater runoff flow leaving the site from pre -
development conditions for the one (I) -year design storm. Developments with less than 10% net
increase in peak flow of the one (I) -year design storm are not required to control peak flow for the one
(I) -year storm from the site. However, if the net increase in peak flow from the new development is
greater than 10%, the entire net increase from pre -development one (I) -year design storm peak flow
must be controlled.
As shown on the Post -Development Conditions exhibit, runoff leaves the site at five (5) points of
discharge or points of study. Peak stormwater runoff was determined using the USDA Technical Release
Number 55 (TR-55) or SCS Method.
Appian Consulting Engineers, PA

Duke Energy Progress
0 0�
The attached calculations demonstrate that post -development peak stormwater runoff flow leaving the
site is less than an 10% increase from pre -development conditions for the one (1)-year design storm
and is therefore exempt from additional stormwater controls.
A
B
C
D
E
Total
PRE -DEVELOPED CONDITIONS (cfs)
35.03
3.71
2.07
7.26
1.72
49.79
POST -DEVELOPED CONDITIONS (cfs)
37.44
3.67
2.09
7.70
1.74
52.64
Difference (%)
6.88%
-1.08%
0.97%
6.06%
1.16%
5.72%
CONCLUSION
This project meets the stormwater requirements set forth in the Town of Cary UDO without the need for
stormwater control measures or nutrient buy -down.
1:1►1We] M9►AILVAMA7
Appian Consulting Engineers, PA

MAPS

DEP Cary- 3150 Green Level West Rd
REID:0005379
PIN:0734218558
PIN Extension: 000
Deed Acres: 37.300000000000004
Township: White Oak
Owner: DUKE ENERGY PROGRESS LLC
Mailing Address 1: DATA & DOCUMENT
MGMT
Mailing Address 2: 550 S TRYON ST DEC 22A
Mailing Address 3: CHARLOTTE NC 28201
Deed Book:017332
Deed Page:01037
Deed Date: 1/4/2019
Map Name: 0734 03
Billing Class: Public
Property Description: DUKE ENERGY
PROGRESS, LLC RCMB BM2023 -00914
Site Address: 3150 GREEN LEVEL WEST RD
Street Name: GREEN LEVEL WEST RD
Old Parcel Number: --
Total Structures: 1
ZIP:27519
A
200 400 800 ft
1 inch equals 400 feet
Disclaimer
iMaps makes every effort to produce and publish
the most current and accurate information possible.
However, the maps are produced for information purposes,
and are NOT surveys. No warranties, expressed or implied,
are provided for the data therein, its use,or its interpretation.

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usoA Natural Resources Web Soil Survey
Conservation Service National Cooperative Soil Survey
Soil Map —Wake County, North Carolina
(DEP CARY)
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Soil Map —Wake County, North Carolina
97:1119G1:0
Map Unit Legend
Map Unit Symbol
Map Unit Name
Acres in AOI
Percent of AOI
ChA
Chewacla and Wehadkee
40.8
15.7%
soils, 0 to 2 percent slopes,
frequently flooded
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Creedmoor-Green Level
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24.2%
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slopes
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Creedmoor-Green Level
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7.1 %
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slopes
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Creedmoor-Green Level
134.7
51.7%
complex, 10 to 15 percent
slopes
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Creedmoor-Green Level -Urban
0.3
0.1 %
land complex, 2 to 10
percent slopes
W
Water
3.3
1.3%
Totals for Area of Interest
260.7
100.0%
USDA Natural Resources Web Soil Survey 5/10/2022
Conservation Service National Cooperative Soil Survey Page 3 of 3

Hydrologic Soil Group —Wake County, North Carolina
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usoA Natural Resources Web Soil Survey
Conservation Service National Cooperative Soil Survey
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Hydrologic Soil Group
Map unit symbol
Map unit name
Rating
Acres in AOI
Percent of AOI
ChA
Chewacla and
B/D
15.4
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frequently flooded
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Creedmoor-Green Level
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124.0
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USDA Natural Resources Web Soil Survey 1/18/2023
Conservation Service National Cooperative Soil Survey Page 3 of 4

Hydrologic Soil Group —Wake County, North Carolina
Description
Hydrologic soil groups are based on estimates of runoff potential. Soils are
assigned to one of four groups according to the rate of water infiltration when the
soils are not protected by vegetation, are thoroughly wet, and receive
precipitation from long -duration storms.
The soils in the United States are assigned to four groups (A, B, C, and D) and
three dual classes (A/D, B/D, and C/D). The groups are defined as follows:
Group A. Soils having a high infiltration rate (low runoff potential) when
thoroughly wet. These consist mainly of deep, well drained to excessively
drained sands or gravelly sands. These soils have a high rate of water
transmission.
Group B. Soils having a moderate infiltration rate when thoroughly wet. These
consist chiefly of moderately deep or deep, moderately well drained or well
drained soils that have moderately fine texture to moderately coarse texture.
These soils have a moderate rate of water transmission.
Group C. Soils having a slow infiltration rate when thoroughly wet. These consist
chiefly of soils having a layer that impedes the downward movement of water or
soils of moderately fine texture or fine texture. These soils have a slow rate of
water transmission.
Group D. Soils having a very slow infiltration rate (high runoff potential) when
thoroughly wet. These consist chiefly of clays that have a high shrink -swell
potential, soils that have a high water table, soils that have a claypan or clay
layer at or near the surface, and soils that are shallow over nearly impervious
material. These soils have a very slow rate of water transmission.
If a soil is assigned to a dual hydrologic group (A/D, B/D, or C/D), the first letter is
for drained areas and the second is for undrained areas. Only the soils that in
their natural condition are in group D are assigned to dual classes.
Rating Options
Aggregation Method: Dominant Condition
Component Percent Cutoff.- None Specified
Tie -break Rule: Higher
USDA Natural Resources Web Soil Survey 1/18/2023
Conservation Service National Cooperative Soil Survey Page 4 of 4

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From: Bailey, David E CIV USARMY CESAW (USA)
To: Dalton, Amv
Cc: Samuels, Kelley; Witherspoon, Josh
Subject: [EXTERNAL] Delineation Concurrence: SAW-2022-02375 (Duke Energy Progress / Cary Triangle Expressway
230kV Substation Project / Wake County)
Date: Friday, December 23, 2022 7:57:48 AM
Attachments: Fiaure7 Aauatic Resources 121622.pdf
0,
I reviewed the information you sent for the above referenced project. Based on your submittal, available remotely
sensed information, and updated delineation map per my comments, no field verification from the Corps is
necessary.
By copy of this e-mail, we are confirming that the aquatic resources delineation has been verified by the Corps to be
sufficiently accurate and reliable for permitting actions and the determination of compensatory mitigation
requirements. The boundaries of these aquatic resources are shown on the attached delineation map entitled
"Figure 7 Aquatic Resources Overview Map", dated December 2022.
Regulatory Guidance Letter (RGL) 16-01 provides guidance for Jurisdictional Determinations (JDs) and states "The
Corps generally does not issue a JD of any type where no JD has been requested". At this time we are only verifying
the delineation. This delineation may be relied upon for use in the permit evaluation process, including determining
compensatory mitigation. This delineation verification is not an Approved Jurisdictional Determination (AJD) and is
not an appealable action under the Regulatory Program Administrative Appeal Process (33 CFR Part 331). However,
you may request an AJD, which is an appealable action.
If you wish to receive a Preliminary Jurisdictional Determination (PJD), or an AJD please respond accordingly,
otherwise nothing further is required and we will not provide any additional documentation pertaining to this
delineation.
Sincerely,
Dave Bailey
David E. Bailey, PWS
Regulatory Project Manager
US Army Corps of Engineers
CE-SAW-RG-R
3331 Heritage Trade Drive, Suite 105
Wake Forest, North Carolina 27587
Mobile: [phone]
Email: David. E.Bailey2Pusace.army.miI
We would appreciate your feedback on how we are performing our duties. Our automated

STORMWATER DIVISION
April 4, 2023
Duke Energy Progress, LLC c/o
Ms. Amy Dalton
AECOM
10 Patewood Drive, Building VI, Suite 500
Greenville, SC 29615
RE: REVISED No Practical Alternatives/Request for Authorization Certificate
Triangle Expressway 230kV Substation
0 Green Level West Road
UT to Bachelor Branch
TCBA-23-002
Dear Ms. Dalton:
The Town has received your No Practical Alternatives/Request for a REVISED Authorization Certificate
to construct an electrical substation, including transmission line right -or -way and an access road, at the
above -referenced property. The project proposes 59,974 square feet of impacts to Jordan Lake
riparian buffers and Urban Transition Buffers (UTBs) associated with a UT to Bachelor Branch.
Upon a thorough review and careful consideration, this request is approved since it meets the no
practical alternatives criteria in the Town of Cary's Land Development Ordinance (LDO) Section 14.6.9.
Below is a summary of approved impacts based on your Revised Buffer Authorization Request received
by this office on April 3, 2023:
Buffer
Temporary or
Buffer
Zone 1
Zone 2
Zone 3
Impact
Permanent
Feature
Mitigation
Impact
Impact
Impact
#
Y/N?
1
Permanent
UT to
N
6,195 SF
4,167 SF
0
(Road crossing)
Bachelor
Branch
2
Permanent
UT to
N
8,350 SF
5,983 SF
11,635 SF
(Road crossing)
Bachelor
Branch
3
Permanent
UT to
N
6,860 SF
4,383 SF
1,941 SF
(Road crossing)
Bachelor
Branch
4
Permanent
UT to
N
6,281 SF
4,179 SF
0
(Electric
Bachelor
transmission line
Branch
ROW
TOTAL
27,686 SF
18,712 SF
13,576 SF
IMPACTS
Appeals of determinations regarding Authorization Certificates for activities in Zone 1 or Zone 2 of the
riparian buffer shall be referred to the Director of the Division of Water Resources, c/o the 401 and
Buffer Permitting Unit, or its successor.
TOWN Of CARY
316 North Academy Street • Cary, NC 27513 • PO Box 8005 • Cary, NC 27512-8005
te1919-469-4030 • fax [phone] • www.townofcary.org

Ms. Dalton
REVISED Jordan Lake Buffer Authorization
April 4, 2023
Page 2 of 2
Thank you for your cooperation in the submittal of your application. Please call me at [phone] if
I can be of further assistance.
Sincerely,
§',�0
Eric W. Kul
Environmental Specialist
Cc: File Copy
TOWN Of CARY
316 North Academy Street • Cary, NC 27513 • PO Box 8005 • Cary, NC 27512-8005
te1919-469-4030 • fax [phone] • www.townofcary.org

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WATER QUANTITY
PEAK FLOW CALCULATIONS

PEAK FLOW CALCULATIONS
DEP Cary Triangle Expressway
Areas calculated by JS, 6/30/23
Total Property Area: 37.30 ac
Point of Study (Point of Discharge): A
PRE -DEVELOPED CONDITIONS
B C D E Tota I
Ex Trees (ac):
25.19
2.13
1.19
3.62
0.26 32.39
Ex Grass/Shrub (ac):
3.74
-
-
0.55
0.62 4.91
Total Drainage Area (ac):
28.93
2.13
1.19
4.17
0.88 37.30
POST -DEVELOPED CONDITIONS
Ex Trees (ac):
13.61
1.10
1.07
3.13
0.26 19.17
New Trees (ac)
5.46
0.17
-
-
- 5.63
Grass/Shrub (ac):
6.09
0.72
0.13
1.04
0.63 8.61
Concrete Entrance (ac):
0.04
-
-
-
- 0.04
Gravel Driveway (ac):
1.11
-
-
-
- 1.11
Gravel Substation (pervious) (ac):
2.15
-
-
-
- 2.15
Reinforced Grass (ac):
0.59
-
-
-
- 0.59
Total Drainage Area (ac):
29.05
1.99
1.20
4.17
0.89 37.30
A B C D E Tota I
PRE -DEVELOPED CONDITIONS
1 yr 24 hr
35.03
3.71
2.07
7.26
1.72
49.79
POST -DEVELOPED CONDITIONS
1 yr 24 hr
37.44
3.67
2.09
7.70
1.74
52.64
Difference (cfs)
2.41
(0.04)
0.02
0.44
0.02
2.85
Difference (%)
✓6.88%
V/-1.085%
✓0.97%
✓6.06%
Vf16%
✓5.72%
if 10% increase in Q1 from pre-dev rate, then site must detain Q1,2,5,10, & Q100 to pre-dev rates

Ex Conditions
S4
Reach and L
ink
A2
Pro Conditions

A
DEP CARY POS A
Prepared by Appian Consulting Engineers, PA Page 2
HvdroCADO 8.00 s/n 003961 © 2006 HvdroCAD Software Solutions LLC 7/5/2023
Area Listing (all nodes)
Area (acres) CN Description (subcats)
5.460 77 New Woods, Good, HSG D (A2)
38.800 77 Woods, Good, HSG D (A,A2)
9.830 80 >75% Grass cover, Good, HSG D (A,A2)
0.590 80 >75% Grass cover, Reinforced (A2)
2.150 80 Gravel within Substation Fence (A2)
1.110 91 Gravel roads, HSG D (A2)
0.040 98 Concrete Entrance (A2)
57.980

A
DEP CARY POS A Type 1124-hr 1-yr24 hour Rainfall=2.86"
Prepared by Appian Consulting Engineers, PA Page 3
HvdroCADO 8.00 s/n 003961 © 2006 HvdroCAD Software Solutions LLC 7/5/2023
Time span=5.00-120.00 hrs, dt=0.05 hrs, 2301 points
Runoff by SCS TR-20 method, UH=SCS
Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method
Subcatchment A: Ex Conditions Runoff Area=28.930 ac Runoff Depth=0.98"
Flow Length=1,500' Tc=15.0 min CN=77 Runoff=35.03 cfs 2.351 of
Subcatchment A2: Pro Conditions Runoff Area=29.050 ac Runoff Depth=1.03"
Flow Length=1,500' Tc=15.0 min CN=78 Runoff=37.44 cfs 2.494 of
Total Runoff Area = 57.980 ac Runoff Volume = 4.845 of Average Runoff Depth = 1.00"
99.93% Pervious Area = 57.940 ac 0.07% Impervious Area = 0.040 ac

A
DEP CARY POS A Type 1124-hr 1-yr24 hour Rainfall=2.86"
Prepared by Appian Consulting Engineers, PA Page 4
HydroCADO 8.00 s/n 003961 © 2006 HydroCAD Software Solutions LLC 7/5/2023
Subcatchment A: Ex Conditions
Inflow Hydrograph
Runoff = 35.03 cfs @ 12.08 hrs, Volume= 2.351 af, Depth= 0.98"
Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-120.00 hrs, dt= 0.05 hrs
Type II 24-hr 1-yr 24 hour Rainfall=2.86"
Area (ac) CN Description
25.190 77 Woods, Good, HSG D
3.740 80 >75% Grass cover, Good, HSG D
28.930 77 Weighted Average
28.930 Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
15.0 1,500 1.67 Direct Entry, Site Flow
w
0
LL
Subcatchment A: Ex Conditions
Hydrograph
i --+--+--+--+--+--+--+------------------+--+--+--+--+--+--+--+------I---
i35.03ds - -- -- -- -- ---------------I--- -- -- -- -- -- -- -- ------I---
- - -- -- -- -- ------------------Tpe_lll, Z4-hr-1 x2 �4hllour--
i --L-L--1--1--1--J--J---------------II-----L--L----Rai nf WF-_2- 6"--
i --L-L--1--1--1--J-- ---1---1---1---1---1---L--L--L--1--1--1---I---I---I---I---
--- ---- -- -- ---------I--- I --- I --- I --- --_kunoffVokme=2:I13511-af_-
-- - -- -- -- ---I-
i --- ---- -- -------------------------------Rurioff-Derlith--.98'--
i - -- -- -- ---------------I-- -I-- - - - -- -- - --
r--- --- - -----
� I I I I I I I I I I
- -- + -- + -- ------------I-- -I-- - - - -- -'rC=1vIII.OjMjn--
I I
i --T- T--T --T -- ---------- -----'--r-- r-- T - -T -- --;--DPI -77--
i --r -r--+--
+
--r--r--r---I---I---I---r--r--r--r--r--r--r--r--r--r---I---I---
5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 105 110 115 120
Time (hours)
— Runoff

A
DEP CARY POS A Type 1124-hr 1-yr24 hour Rainfall=2.86"
Prepared by Appian Consulting Engineers, PA Page 5
HydroCADO 8.00 s/n 003961 © 2006 HydroCAD Software Solutions LLC 7/5/2023
Subcatchment A2: Pro Conditions
Inflow Hydrograph
Runoff = 37.44 cfs @ 12.08 hrs, Volume= 2.494 af, Depth= 1.03"
Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-120.00 hrs, dt= 0.05 hrs
Type II 24-hr 1-yr 24 hour Rainfall=2.86"
Area (ac)
CN
Description
13.610
77
Woods, Good, HSG D
5.460
77
New Woods, Good, HSG D
6.090
80
>75% Grass cover, Good, HSG D
0.590
80
>75% Grass cover, Reinforced
2.150
80
Gravel within Substation Fence
1.110
91
Gravel roads, HSG D
0.040
98
Concrete Entrance
29.050
78 Weighted Average
29.010
Pervious Area
0.040
Impervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
15.0 1,500 1.67 Direct Entry, Site Flow
Subcatchment A2: Pro Conditions
Hydrograph
— Runoff
Type -Ill 4-fir'1 yr-24hourr--
L-L--1--1--i--J-- L--L-- --
Rainf9Nr2-8
--+-+--+--+--+--+--+--+--+------+----- -R"cyff-Area=�9�5-q ale--
--}-}--+--+--�--�--�---�---�---�---�---�--Au'vo#f-VAD ume=2-494-0 -
I --r -r rt--rt-----------r-----r--r--u olil DPi LhT 1 ,VVH--
-- -- -- -- -- - Flow-Lervgtlr9-, 01�'--
-- - -- -- -- -- -- -- -- -- -- ----------------
--',- L
-- ---II ---II------------------II - -- II-- - --- II - -- II--- -- --C�I��-7Ij8--
5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 105 110 115 120
Time (hours)

Ex Conditions
S4
Reach and Link
Pro Conditions

B
DEP CARY POS B
Prepared by Appian Consulting Engineers, PA Page 2
HvdroCADO 8.00 s/n 003961 © 2006 HvdroCAD Software Solutions LLC 7/5/2023
Area Listing (all nodes)
Area (acres) CN Description (subcats)
0.170 77 New Woods, Good, HSG D (132)
3.230 77 Woods, Good, HSG D (13,132)
0.720 80 >75% Grass cover, Good, HSG D (13,132)
0.000 80 >75% Grass cover, Reinforced (132)
0.000 80 Gravel within Substation Fence (132)
0.000 91 Gravel roads, HSG D (132)
0.000 98 Concrete Entrance (132)
4.120

B
DEP CARY POS B Type 1124-hr 1-yr24 hour Rainfall=2.86"
Prepared by Appian Consulting Engineers, PA Page 3
HvdroCADO 8.00 s/n 003961 © 2006 HvdroCAD Software Solutions LLC 7/5/2023
Time span=5.00-120.00 hrs, dt=0.05 hrs, 2301 points
Runoff by SCS TR-20 method, UH=SCS
Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method
Subcatchment B: Ex Conditions Runoff Area=2.130 ac Runoff Depth=0.98"
Flow Length=500' Tc=5.0 min CN=77 Runoff=3.71 cfs 0.173 of
Subcatchment 132: Pro Conditions Runoff Area=1.990 ac Runoff Depth=1.03"
Flow Length=500' Tc=5.0 min CN=78 Runoff=3.67 cfs 0.171 of
Total Runoff Area = 4.120 ac Runoff Volume = 0.344 of Average Runoff Depth = 1.00"
100.00% Pervious Area = 4.120 ac 0.00% Impervious Area = 0.000 ac

B
DEP CARY POS B Type 1124-hr 1-yr24 hour Rainfall=2.86"
Prepared by Appian Consulting Engineers, PA Page 4
HydroCADO 8.00 s/n 003961 © 2006 HydroCAD Software Solutions LLC 7/5/2023
Subcatchment B: Ex Conditions
Inflow Hydrograph
Runoff = 3.71 cfs @ 11.96 hrs, Volume= 0.173 af, Depth= 0.98"
Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-120.00 hrs, dt= 0.05 hrs
Type II 24-hr 1-yr 24 hour Rainfall=2.86"
Area (ac) CN Description
2.130 77 Woods, Good, HSG D
0.000 80 >75% Grass cover, Good, HSG D
2.130 77 Weighted Average
2.130 Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
5.0 500 1.67 Direct Entry, Site Flow
w
0
LL
Subcatchment B: Ex Conditions
Hydrograph
--L--L--L--1--1--1--1--J--J---1---1---1---1---1---1---L--L--L--L--1--1--1--
3.71 cfs
Type II 24-hr 1 yr 24 hour
Rainfc1IIT2,86"
Runoff Area=2.13Q a;c
Runoff volume=0.173 of
--+--+-- -- - Rurioff_aeothr0198,"
FI'oW L;en',gth=OOQ'
Yc;=5! 0 m i n
-- -- -- C - =77_
5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 105 110 115 120
Time (hours)
— Runoff

B
DEP CARY POS B Type 1124-hr 1-yr24 hour Rainfall=2.86"
Prepared by Appian Consulting Engineers, PA Page 5
HydroCADO 8.00 s/n 003961 © 2006 HydroCAD Software Solutions LLC 7/5/2023
Subcatchment 1132: Pro Conditions
Inflow Hydrograph
Runoff = 3.67 cfs @ 11.96 hrs, Volume= 0.171 af, Depth= 1.03"
Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-120.00 hrs, dt= 0.05 hrs
Type II 24-hr 1-yr 24 hour Rainfall=2.86"
Area (ac)
CN
Description
1.100
77
Woods, Good, HSG D
0.170
77
New Woods, Good, HSG D
0.720
80
>75% Grass cover, Good, HSG D
0.000
80
>75% Grass cover, Reinforced
0.000
80
Gravel within Substation Fence
0.000
91
Gravel roads, HSG D
0.000
98
Concrete Entrance
1.990 78 Weighted Average
1.990 Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
5.0 500 1.67 Direct Entry, Site Flow
w
0
LL
Subcatchment 1132: Pro Conditions
Hydrograph
3.67 cfs
Type II 24-hr 1 yr 24 hour
RainfaIIT2,86"
{ - - 7 - T - - T - - T - - T - - 7 - - 7 - - 7 - - 7 7 - - 7 - - T - - T - - T - - T - - 7 - -
Runoff Arga=1.$9Q a;c
Runoff Volume=0.,17,1 of
Runoff-Dep�th#l.,O
FI'oW L;en',gth=OOQ'
Yc;=5! 0 m i n
--'L-L--L--1--1--i--i--J-- CK=78-
5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 105 110 115 120
Time (hours)
— Runoff

Ex Conditions
S4
Reach and L
ink
C2
Pro Conditions

C
DEP CARY POS C
Prepared by Appian Consulting Engineers, PA Page 2
HydroCADO 8.00 s/n 003961 © 2006 HydroCAD Software Solutions LLC 7/3/2023
Area Listing (all nodes)
Area (acres) CN Description (subcats)
2.260 77 Woods, Good, HSG D (C,C2)
0.130 80 >75% Grass cover, Good, HSG D (C,C2)
2.390

C
DEP CARY POS C Type 1124-hr 1-yr24 hour Rainfall=2.86"
Prepared by Appian Consulting Engineers, PA Page 3
HvdroCADO 8.00 s/n 003961 © 2006 HvdroCAD Software Solutions LLC 7/3/2023
Time span=5.00-120.00 hrs, dt=0.05 hrs, 2301 points
Runoff by SCS TR-20 method, UH=SCS
Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method
Subcatchment C: Ex Conditions Runoff Area=1.190 ac Runoff Depth=0.98"
Flow Length=260' Tc=5.0 min CN=77 Runoff=2.07 cfs 0.097 of
Subcatchment C2: Pro Conditions Runoff Area=1.200 ac Runoff Depth=0.98"
Flow Length=260' Tc=5.0 min CN=77 Runoff=2.09 cfs 0.098 of
Total Runoff Area = 2.390 ac Runoff Volume = 0.194 of Average Runoff Depth = 0.98"
100.00% Pervious Area = 2.390 ac 0.00% Impervious Area = 0.000 ac

C
DEP CARY POS C Type 1124-hr 1-yr24 hour Rainfall=2.86"
Prepared by Appian Consulting Engineers, PA Page 4
HydroCADO 8.00 s/n 003961 © 2006 HydroCAD Software Solutions LLC 7/3/2023
Subcatchment C: Ex Conditions
Inflow Hydrograph
Runoff = 2.07 cfs @ 11.96 hrs, Volume= 0.097 af, Depth= 0.98"
Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-120.00 hrs, dt= 0.05 hrs
Type II 24-hr 1-yr 24 hour Rainfall=2.86"
Area (ac) CN Description
1.190 77 Woods, Good, HSG D
0.000 80 >75% Grass cover, Good, HSG D
1.190 77 Weighted Average
1.190 Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
5.0 260 0.87 Direct Entry, Site Flow
w
0
LL
Subcatchment C: Ex Conditions
Hydrograph
2.07 cfs
T�pe 11 24 rr-1 yr hour-
Rainf6llT2�86..
Runoff Area=1.19Q a'c
Runoff Volume 0.,097 of
Runoff Dep�thr0198,..
- -- -- F1ovV-Lenth-�6Q'-
Yc;=5! 0 m i n
CN'=77
5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 105 110 115 120
Time (hours)
— Runoff

C
DEP CARY POS C Type 1124-hr 1-yr24 hour Rainfall=2.86"
Prepared by Appian Consulting Engineers, PA Page 5
HydroCADO 8.00 s/n 003961 © 2006 HydroCAD Software Solutions LLC 7/3/2023
Subcatchment C2: Pro Conditions
Inflow Hydrograph
Runoff = 2.09 cfs @ 11.96 hrs, Volume= 0.098 af, Depth= 0.98"
Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-120.00 hrs, dt= 0.05 hrs
Type II 24-hr 1-yr 24 hour Rainfall=2.86"
Area (ac) CN Description
1.070 77 Woods, Good, HSG D
0.130 80 >75% Grass cover, Good, HSG D
1.200 77 Weighted Average
1.200 Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
5.0 260 0.87 Direct Entry, Site Flow
w
0
LL
Subcatchment C2: Pro Conditions
Hydrograph
2.09 cfs
-- -,Type It 24 hr-11r 24-hour-
RainfallT2,86;..
Runoff Arga=1.�0Q a;c
Runoff Volume 0.,0918 of
Runoff Dep�thr0198,..
-r--r--T--T-- -----------'---'---'--------- -Flovylen';gtI -=�SQV
Yc;=5! 0 m i n
CN'=77
5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 105 110 115 120
Time (hours)
— Runoff

Ex Conditions
S4
Reach and L
ink
D2
Pro Conditions

D
DEP CARY POS D
Prepared by Appian Consulting Engineers, PA Page 2
HydroCADO 8.00 s/n 003961 © 2006 HydroCAD Software Solutions LLC 7/3/2023
Area Listing (all nodes)
Area (acres) CN Description (subcats)
6.750 77 Woods, Good, HSG D (D,D2)
1.590 80 >75% Grass cover, Good, HSG D (D,D2)
8.340

D
DEP CARY POS D Type 1124-hr 1-yr24 hour Rainfall=2.86"
Prepared by Appian Consulting Engineers, PA Page 3
HvdroCADO 8.00 s/n 003961 © 2006 HvdroCAD Software Solutions LLC 7/3/2023
Time span=5.00-120.00 hrs, dt=0.05 hrs, 2301 points
Runoff by SCS TR-20 method, UH=SCS
Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method
Subcatchment D: Ex Conditions Runoff Area=4.170 ac Runoff Depth=0.98"
Flow Length=600' Tc=5.0 min CN=77 Runoff=7.26 cfs 0.339 of
Subcatchment D2: Pro Conditions Runoff Area=4.170 ac Runoff Depth=1.03"
Flow Length=600' Tc=5.0 min CN=78 Runoff=7.70 cfs 0.358 of
Total Runoff Area = 8.340 ac Runoff Volume = 0.697 of Average Runoff Depth = 1.00"
100.00% Pervious Area = 8.340 ac 0.00% Impervious Area = 0.000 ac

D
DEP CARY POS D Type 1124-hr 1-yr24 hour Rainfall=2.86"
Prepared by Appian Consulting Engineers, PA Page 4
HydroCADO 8.00 s/n 003961 © 2006 HydroCAD Software Solutions LLC 7/3/2023
Subcatchment D: Ex Conditions
Inflow Hydrograph
Runoff = 7.26 cfs @ 11.96 hrs, Volume= 0.339 af, Depth= 0.98"
Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-120.00 hrs, dt= 0.05 hrs
Type II 24-hr 1-yr 24 hour Rainfall=2.86"
Area (ac) CN Description
3.620 77 Woods, Good, HSG D
0.550 80 >75% Grass cover, Good, HSG D
4.170 77 Weighted Average
4.170 Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
5.0 600 2.00 Direct Entry, Site Flow
w
0
LL
Subcatchment D: Ex Conditions
Hydrograph
7.26 cfs
T�pe1124hr-� yr h�our-
RainfMI:T218
Runoff Area=4.17Q a;c
uno ff V o umU33 e=.af-
Ru�loff-De p�t #-0,9V - --J-J--J--J--J--J--J--J--J------------I- I-
FIoW L;en',gth=OOQ.
L__L__ L_ J J_�1__
c=5�� �nin
-' - -- -- -- -- -- -- --------------------'---' --' -- -- -- =77-
5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 105 110 115 120
Time (hours)
— Runoff

D
DEP CARY POS D Type 1124-hr 1-yr24 hour Rainfall=2.86"
Prepared by Appian Consulting Engineers, PA Page 5
HydroCADO 8.00 s/n 003961 © 2006 HydroCAD Software Solutions LLC 7/3/2023
Subcatchment D2: Pro Conditions
Inflow Hydrograph
Runoff = 7.70 cfs @ 11.96 hrs, Volume= 0.358 af, Depth= 1.03"
Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-120.00 hrs, dt= 0.05 hrs
Type II 24-hr 1-yr 24 hour Rainfall=2.86"
Area (ac) CN Description
3.130 77 Woods, Good, HSG D
1.040 80 >75% Grass cover, Good, HSG D
4.170 78 Weighted Average
4.170 Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
5.0 600 2.00 Direct Entry, Site Flow
Subcatchment D2: Pro Conditions
Hydrograph
7.70ds- T-- T--T--T--T - -T -- ---------r-----T-----F--F--T--T--T--T--T--
LLTT11 -- -- Type II���24-hr_1L�r24-h�ouir-
iT2,8 Ranfall6;..
- - -- -- -- -- -- -- -- --- Ru oft-ArOa=4.17Q-a;c-
-------+--+-- -----,---,---,---,---,--lkunoff VoJIJniae=4.358-af-
Rurloff Depthr1103,..
--- -----------------------------------------------------------------
FI'oW L;en',gth=OOQ.
CN�'�=78
5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 105 110 115 120
Time (hours)
— Runoff

E
Ex Conditions
S4
Reach and L
ink
E2
Pro Conditions

E
DEP CARY POS E
Prepared by Appian Consulting Engineers, PA Page 2
HydroCADO 8.00 s/n 003961 © 2006 HydroCAD Software Solutions LLC 7/3/2023
Area Listing (all nodes)
Area (acres) CN Description (subcats)
0.520 77 Woods, Good, HSG D (E,E2)
1.250 80 >75% Grass cover, Good, HSG D (E,E2)
1.770

E
DEP CARY POS E Type 1124-hr 1-yr24 hour Rainfall=2.86"
Prepared by Appian Consulting Engineers, PA Page 3
HvdroCADO 8.00 s/n 003961 © 2006 HvdroCAD Software Solutions LLC 7/3/2023
Time span=5.00-120.00 hrs, dt=0.05 hrs, 2301 points
Runoff by SCS TR-20 method, UH=SCS
Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method
Subcatchment E: Ex Conditions Runoff Area=0.880 ac Runoff Depth=1.09"
Flow Length=500' Tc=5.0 min CN=79 Runoff=1.72 cfs 0.080 of
Subcatchment E2: Pro Conditions Runoff Area=0.890 ac Runoff Depth=1.09"
Flow Length=500' Tc=5.0 min CN=79 Runoff=1.74 cfs 0.081 of
Total Runoff Area = 1.770 ac Runoff Volume = 0.160 of Average Runoff Depth = 1.09"
100.00% Pervious Area = 1.770 ac 0.00% Impervious Area = 0.000 ac

E
DEP CARY POS E Type 1124-hr 1-yr24 hour Rainfall=2.86"
Prepared by Appian Consulting Engineers, PA Page 4
HydroCADO 8.00 s/n 003961 © 2006 HydroCAD Software Solutions LLC 7/3/2023
Subcatchment E: Ex Conditions
Inflow Hydrograph
Runoff = 1.72 cfs @ 11.96 hrs, Volume= 0.080 af, Depth= 1.09"
Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-120.00 hrs, dt= 0.05 hrs
Type II 24-hr 1-yr 24 hour Rainfall=2.86"
Area (ac) CN Description
0.260 77 Woods, Good, HSG D
0.620 80 >75% Grass cover, Good, HSG D
0.880 79 Weighted Average
0.880 Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
5.0 500 1.67 Direct Entry, Site Flow
N
U
0
LL
Subcatchment E: Ex Conditions
Hydrograph
1.72 cfs
Type II 24-hr 1 yr 24 h'�our
RainfaIIT2,86..
Iuof Arpa=0.88Q a;c
Ikunoff Volume 0.080 of
- - -- -- -- -- -- -- -- --- -- ]Ru"ffDeppthr1.09`.'
FI'ovy L;en',gth=60Q.
Yc;=50 min
C N=79
5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 105 110 115 120
Time (hours)
— Runoff

E
DEP CARY POS E Type 1124-hr 1-yr24 hour Rainfall=2.86"
Prepared by Appian Consulting Engineers, PA Page 5
HydroCADO 8.00 s/n 003961 © 2006 HydroCAD Software Solutions LLC 7/3/2023
Subcatchment E2: Pro Conditions
Inflow Hydrograph
Runoff = 1.74 cfs @ 11.96 hrs, Volume= 0.081 af, Depth= 1.09"
Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-120.00 hrs, dt= 0.05 hrs
Type II 24-hr 1-yr 24 hour Rainfall=2.86"
Area (ac) CN Description
0.260 77 Woods, Good, HSG D
0.630 80 >75% Grass cover, Good, HSG D
0.890 79 Weighted Average
0.890 Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
5.0 500 1.67 Direct Entry, Site Flow
N
U
0
LL
Subcatchment E2: Pro Conditions
Hydrograph
1.74 cfs
Type II 24-hr 1 yr 24 h'�our
RainfaIIT2,86..
Iuof Arpa=0.89Q a;c
Otunoff Volume 0.081 of
-- -- -- ------------Rurtoff-Dept-hr Fye
FI'ovy L;en',gth=60Q.
Yc;=50 min
C N=79
5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 105 110 115 120
Time (hours)
— Runoff

WATER QUALITY CALCULATIONS:
SNAP TOOL 4.2

SNAP TOOL INFORMATION WORKSHEET
Information for Entry into SNAP Version 4.2.0
Project Name:
Date Prepared:
Prepared by: Appian
Site Information:
Disturbed Area:
Total Property Size:
Total Reg/UnReg Area:
Pre -Project Land Characteristics:
Roof
Roadway
Parking/Driveway/Sidewalk
DEP Cary Triangle Expressway
6/23/2023
dcr
a c sf
14.00 609,840
37.30 1,624,788
37.30 1,624,788
a c sf
Protected Forest 4.47 194,832
Managed Pervious/Landscaping (total) 32.83 1,429,956
Existing Grass
Offsite or Existing Roof -
Offsite or Existing Roadway -
Offsite or Existing Parking/Driveway/Sidewalk - -
Offsite Protected Forest -
Offsite Managed Pervious -
Land Taken up by SCM - -
Total Reg/UnReg Area: 37.30 1,624,788
Post -Project Land Characteristics:
ac
sf
Roof
-
-
Roadway (total)
0.04
1,781
Pro Concrete Entrance
0.04
1,781
Parking/Driveway/Sidewalk (total)
1.11
48,367
Pro Gravel Driveway (less stone shoulder outside substation fence)
1.11
48,367
Protected Forest
3.58
156,126
Managed Pervious/Landscaping (total)
32.56
1,418,514
Unprotected Ex Trees
15.59
678,919
Unprotected New Trees/Landscaping
5.63
245,243
Grass/Shrubs
8.61
375,052
Pro Gravel within Substation Fence
2.15
93,600
Pro Reinforced Grass/Geoweb
0.59
25,700
Offsite or Existing Roof - -
Offsite or Existing Roadway - -
Offsite or Existing Parking/Driveway/Sidewalk - -
Offsite Protected Forest - -
Offsite Managed Pervious - -
Land Taken up by SCM - -
Total Reg/UnReg Area: 37.30 1,624,788
Net BUA
Roadway (total) 0.04 1,781
Parking/Driveway/Sidewalk (total) 1.11 48,367
TOTAL POST -DEVELOPED BUA: 1.15 50,148
3.09

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Nutrient Export Summary
SNAP v4.2.0
Landcover 8 SCM Data Review
Frrnrs / Advisories Frrnrc / Advisories
Avg Annual precip (in) =
46.22
SCM Area (ft) =
0
Total (Regulated +
1,624,788
SCM Treated Area
Unregulated) Area (ft) _
Project (Regulated)
Area _
1,624,788
Catchment Routing:
No errors
(ft)
Treating Runoff from
Net BUA ( Project Area
BUA only ft�) =
50,148
Net BUA indicates new development
or expansion.
Existing BUA or Offsite:
Disturbed Area (ft) =
no
609,540
Custom Landcovers are
no
present:
Total Phosphorus
Export Target
ze.oe
Total Nitrogen Export Target
164.1z
Scaled to Project Area (lb/yr):
Scaled to Project Area (lb/yr):
Total Area
Total Area
Project Area
Total Area Project Area
Total Area Project Area
Total Area Project Area
Nutrient Export Summary
Project Area
(Onsite +
(Onsite Only)
Post -Project
Post -Project
Post -Project Post -Project
Post -Project Post -Project
Post -Project Post -Project
Offsite)
Pre -Project Pre -Protect
before
Treatment
before
Treatment
after after
Treatment Treatment
SCM-Treated SCM-Treated
Area Only Area Only
Untreated
Areas
Untreated
Areas
Area (All Landcover Types) (acres)
37.3000 37.3000
37.3000
37.3000
37.3000 37.3000
0.0000 0.0000
37.3000
37.3000
Percent Built -Upon Area (BUA) (%)
0% 0%
3%
1 3%
3% 3%
0% 0%
3% I
3%
Built -Upon Area (BUA) (sgft)
_
0 0
50,148
50,148
50,148 50,148
0 0
50,148
50,148
Annual Runoff Volume (ft'/yr)
251,616 251616
435,071
435,071
435,071 435,071
0 0
435,071
435,071
Annual Runoff %Change
56%
56%
56% 56%
�������
���
��
Total Runoff Change (cuft/yr)
156,454
156,454
156,454 156,454
Total Nitrogen EMC(mg/L)
2.30 2.30
1.99 1.99
1.99
1.99
0.00 0.00
1.99
1.99
Total Nitrogen Load Leaving Site (lb/yr)
40.43
54.44
54.44
54.44
0.00 0.00
54.44
54.44
54.44
Total Nitrogen Loading Rate (1blac/yr)
�4043
1.08 1.OS
1.46
1.46
1.46
0.00 0.00
1.46
1.46
1.46
Total Nitrogen %Change Pre -to -Post
35%
35%
35%
35%
Total Nitrogen Change (Ib/yr) Pre -to -Post
14.01
14.01
14.01
ML
14.01
Total Phosphorus EMC(mg/L)
0.95 0.95
0.67 0.67
0.67
0.67
0.00 0.00
0.67
0.67
Total Phosphorus Load Leaving Site (lb/yr)
16.62 16.62
18.39
18.39
18.39
0.00 1 0.00
18.39
18.39
18.39
Total Phosphorus Loading Rate (Ib/ac/yr)
0.45 0.45
0.49
0.49
0.00 0.00
0.49
0.49
0.49
0.49
Total Phosphorus %Change Pre -to -Post
11%
11%
11%
11%
Total Phosphorus Change (lb/yr)Pre-to-Post
1.77
1.77
1.77
1.77
SCM/Catchment Summary
SCM ID and Type
Volume
Reduction (.)
TN Reduction
(91)
TP Reduction
M)
TN Out
(lbs/ac/yr)
TP Out
(lbs/ac/yr)
Catchment 1
0.00%
0.00%
0.00%
0.00
0.00
101: NA
0.00%
0.00%
0.00%
0.00
0.00
102: NA
0.00%
0.00%
0.00%
0.00
0.00
103: NA
0.00%
0.00%
0.00%
0.00
0.00
Catchment
0.00%
0.00%
0.00%
0.00
0.00
707NA
0.00%
0.00%
0.00%
0.00
0.00
202: NA
0.00%
0.00%
0.00%
0.00
0.00
203: NA
0.00%
1 0.00%
0.00%
0.00
1 0.00
Catchment
0.00%
0.00%
0.00%
0.00
0.00
TOTNA
0.00%
0.00%
0.00%
0.00
0.00
302: NA
0.00%
0.00%
0.00%
0.00
0.00
303: NA
0.00%
0.00%
0.00%
0.00
0.00
Catchment4
0.00%
0.00%
0.00%
0.00
0.00
401: NA
0.00%
0.00%
0.00%
0.00
0.00
402: NA
0.00%
0.00%
0.00%
0.00
0.00
403: NA
0.00%
1 0.00%
0.00%
0.00
0.00
Catchments
0.00%
0.00%
0.00%
0.00
0.00
sot: NA
0.00%
0.00%
0.00%
0.00
0.00
502: NA
0.00%
0.00%
0.00%
0.00
0.00
503: NA
0.00%
0.00%
0.00%
0.00
0.00
Catchment
0.00%
0.00%
0.00%
0.00
0.00
601: NA
0.00%
0.00%
0.00%
0.00
0.00
602: NA
0.00%
0.00%
0.00%
0.00
0.00
603: NA
0.0w/
0.00%
0.00%
1 0.00
0.00
Falls Lake ONLY: Onsite Reduction Compliance Check
Nitrogen
Phosphorus
Onsite % Reduction Requirement
Export Target Scaled to Area (lb/yr)
164.12
29.09
Export Load Post -Project Before Treatment
54.44
18.39
Total Reduction Need (lb/yr)
Onsite Reduction Need (lb/yr)
Onsite Export Target (lb/yr)
Project Area Post -Project After Treatment
54.44
18.39
NO SCMS REQUIRED OR PROPOSED

Nutrient Management Strategy Watershed - Nutrient Offset Credit Reporting Form
SNAP 4.2.0
Please complete and submit the following information to the local government permitting your development project
to characterize it and assess the need to purchase nutrient offset credits. Contact and rule implementation
information can be found online at:
http://deg. nc.gov/a bo ut/d ivis io ns/wate r-reso u rces/plan ni ng/nonpoint-sou rce-ma nagement/n ut rie nt-offset-i nformation
PROJECT INFORMATION
Applicant Name: Duke Energy Progress
Project Name: Duke Energy Progress Cary Triangle
Project Address: 315 Green Level West Road
Date: (mm/dd/yyyy) Development Land Use Type: Commercial
County: Wake Project Activity Type: Greenfield Development
Project Area (sqft): 1,624,788 Project Latitude: 35.788714
Post -Project Built -Upon Area %: 3.09% 1 Project Longitude:-78.889097
Nutrient Management Watershed
Subwatershed
Nitrogen Delivery Zone'.
Phosphorus Delivery Zone'.
WATERSHED INFORMATION
Jordan Lake
Lower —New —Hope
Jordan - 060160
Jordan - 060160
N Target Export Rate (lb/ac/yr):
4.40
P Target Export Rate (lb/ac/yr):
0.78
Nitrogen Delivery Factor:
85%
Phosphorus Delivery Factor:
90%
PERMANENT NUTRIENT OFFSET REQUEST
Post -Project Nitrogen Calculations - Projects with No Offsite or Built -Upon Area
(A)
(B)
(C)
(D)
(F)
(G)
(Where
Applicable)
TN Export
TN Remaining
TN Permanent
Additional
Total TN
TN Untreated
Target Load
TN Treated
Reduction
TN Delivery
Offsets
Local Gov't
Permanent
Load (lb/yr)
(Ib/yr)
Load (lb/yr)
Need (Ib/yr)
Factor (%)
Required
Offsets (Ib/yr)
Offsets to
(lb/yr)
Buy (lb/yr)
54.4
1 164.1
1 54.4
1 0.0
1
1 85.0%
1 0.0
I 0.0
Post -Project Phosphorus Calculations - Projects with No Offsite or Built -Upon Area
(A)
(B)
(C)
(D)
(F)
(G)
(Where
Applicable)
TP Export
TP Remaining
TP Permanent
Additional
Total TP
TP Untreated
Target Load
TP Treated
Reduction
TP Delivery
Offsets
Local Gov't
Permanent
Load (lb/yr)
(Ib/yr)
Load (lb/yr)
Need (Ib/yr)
Factor (%)
Required
Offsets (Ib/yr)
Offsets to
(lb/yr)
Buy (lb/yr)
I 0.0
18.4
1 29.1
1 18.4
1 0.0
1
1 90.0%
1 0.0
LOCAL GOVERNMENT AUTHORIZATION
Local Govei
Staff Name
Staff Email

Jordan Lake Developer Nutrient Reporting Form
Please complete and submit the following information to the local government permitting your development project to
characterize it and assess the need to purchase nutrient offsets. Contact and rule implementation information can be
found online at http://portal.ncdenr.org/web/wq/ps/nps/nutrientoffsetintro.
PROJECT INFORMATION (for Jordan Lake)
Applicant Name' Duke Energy Progress, LLC
Project Name: Duke Energy Progress Cary Triangle Expressway
Project Address (if available): Street: City/Town: County:
3150 Green Level Road West Cary, NC Wake
Date: (mo/d/yr)
Project
Lat: (decimal degrees)
Long: (decimal degrees)
July 6, 2023
Location :
35.788714
-78.889097
Is this Redevelopment? ❑ - Yes
Development Type (Please check all that apply)
®- No
Impervious Cover (%):
(Pre -Construction)
�•��%
�
Commercial
E]
Mixed -Use
�
I -
Single Fam. Residential
E]�
Industrial
❑
Duplex Residential
❑
Multi-Fam. Residential
Impervious Cover (%):
o
3.09 /o
El
Institutional
(Post -Construction)
JORDAN WATERSHED INFORMATION
Small Watershed ID (6 digits): (See next page or online map.)
New Development Load Requirements (See individual rules
060160
for a full description of nutrient requirements.)
Jordan Subwatershed (Please check one)
Loading Rate Targets
Offsite Thresholds
Nitrogen N & Phosphorus P
6 N Ibs/ac Residential;
❑
Upper New Hope
2.2 N Ib/ac/yr
10 N Ibs/ac Commercial
0.82 P Ib/ac/yr
(must meet all onsite treatment
requirements)
IX
Lower New Hope
4.4 N Ib/ac/yr
0.78 P Ib/ac/yr
NUTRIENT OFFSET REQUEST(Must meet the offsite thresholds — see above)
Nitrogen Loading / Offset Needs
(A)
(B)
I (C)
(D)
I (E)
I (F)
I (G)
(H)
Untreated
Treated
Loading Rate
Reduction
Project
Offset
Delivery
State Buy Down
Loading Rate
Loading Rate
Target
(Ibs/ac/yNeed r)
Size (ac)
Duration (yrs)
Factor (%)
Amount (Ibs)
(Ibs/ac/yr)
(Ibs/ac/yr)
(Ibs/ac/yr)
B- C
D* E* F* G
54.4
164.1
54.4
0.0
37.30
30
85.0%
0.0
Phosphorus Loading / Offset Needs
(A)
(B)
(C)
(D) I
(E)
I (F)
I (G)
(H)
Untreated
Treated
Loading Rate
Reduction Need
Project
Offset
Delivery
State Buy Down
Load Rate
Load Rate
Target
(Ibs/ac/yr)
Size (ac)
Duration (yrs)
Factor (%)
Amount (Ibs)
(Ibs/ac/yr)
(Ibs/ac/yr)
(Ibs/ac/yr)
B- C
D* E* F* G
18.4
29.1
18.4
0.0
37.30
30
90.0%
0.0
Control of Peak Stormwater Flow (1 year 24 hour design storm)
Calculated Predevelopment Peak Flow
Calculated Post Development Peak Flow
Flow Control Method
49.79 cfs (all points of discharge)
52.64 cfs (all points of discharge)
n/a
° Increase
Authorizing Local Government Name:
Town Of Cary
Staff Name:
Staff Email:
Phone:
Jordan Nutrient Load Reporting Form. September 12, 2012

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_

CREEK CROSSING #1
CALCULATIONS

CULVERT CALCULATIONS
Project: DEP Cary Triangle Expressway
Description: CREEK CROSSING #1
COHSIILTtNG EN�NEERS, PA
Designer: dcr
Date: 5/15/2023
1.1 Based on NCDOT topo, the contributing watershed for this culvert is 21.5 acres (see attached Runoff Map).
1.2 The watershed characteristics can be approximated as follows:
Total;
ACRES
CN
DESCRIPTION
8.0
55
Woods, Good, HSG B
0.5
85
Gravel Roads, HSG B
4.0
61
>75% Grass cover good HSG B
9.0
1 98
JPaved Roads
21.5
1 75
Weighted CN
1.3 Using the SCS Method and rainfall information from NOAA at this location, the peak runoff rates are as follows:
STORM (24 hr)
FLOW (cfs)
1-yr
22.81
2-yr
34.14
10-yr
67.77
25-yr
88.96
50-yr
106.39
100-yr
124.06
500-yr
167.81
1000-yr
186.78
(see attached hydrographs)

CREEK CROSSING #1
Based on NCDOT contours, there should be a culvert that directs flow from NCDOT ROW into this creek (beyond scope o
topographical survey). Since this culvert carries runoff from fully developed areas and NCDOT transportation corridors, i
will be designed to safely pass the 50 year storm without impoundment of water, and the 1,000 year storm does not ex(
top of headwall (see attached hydrographs). A single 60" RCP is proposed at this location.
3. US COE CULVERT REQUIREMENTS
3.1 Per US COE NWP 57, Regional Conditions for Culvert:
9. Culvert Placement. For all NWPs that allow for culvert placement, the following
conditions shall be applied:
a. For all NWPs that involve the con structi onli nstallation of culverts, measures shall be included in the
construct ol Ration that will promote the safe passage of fish and other aquatic organisms
33
Placement of culverts and other structures in streams shall be below the elevation of the streambed by one foot for
all culverts with a diameter greater than 48 inches, and 20% of the culvert diameter for culverts having a diameter
less than or equal to 48 inches. If the culvert outlet is submerged within a pool or scour hole and designed to provide
for aquatic passage, then culvert burial into the streambed is not required.
Culvert burial is not required for structures less than 72 inch diameterAvidth, where the slope of the culvert will be
greater than 2.5%, provided that all alternative options for flattening the slope have been investigated and aquatic
life move me nticonnectivity has been provided when possible (e.g., rock ladders, cross vanes, sills, baffles etc.).
Culvert burial is not required when bedrock is present in culvert locations.
Installation of culverts in wetlands shall ensure continuity of water movement and be designed to adequately
accommodate high water or flood conditions. When roadways, causeways, or other fill projects are constructed
across FEMA-designated floodways or wetlands, openings such as culverts or bridges shall be provided to maintain
the natural hydrology of the system as well as prevent constriction of the floodway that may result in destabilization
of streams or wetlands.
Circular
Culver!
Wse
StM.Lt— joiameler}
Me[ena
t
2 Inches
nrerk
A waiver from the depth specifications in this condition may be requested, in writing, by the permittee and issued by
the Corp. This waiver request must be specific as to the reascns(s) for the request. The waiver will be issued if it
can be demonstrated that the proposed design would result in less impacts to the aquatic environment. Culverts
placed across wetland fills purely for the purposes of equalizing surface water do not have to be buried, but the
culverts must be of adequate size and/or number to ensure unrestricted transmission of water.
b. Bank -full flows (or less) shall be accommodated through maintenance of the existing bank -full channel cross
sectional area. Additional culverts or culvert barrels at such crossings shall be allowed only to receive bank -full
flows.
Approach Fit
Roadway
Culvertburied
Bankfull belowstreambed
- - - - - to appropriate
depth Ufie—ii—d).
$at27ei Stream
Slucka& t3ottom
c. Culverts shall be designed and installed in such a manner that the original stream profiles are not altered and
allow for aquatic life movement during low flows. The dimension, pattern, and profile of the stream above and below
a pipe or culvert shall not be modified by widening the stream channel or by reducing the depth of the stream in
connection with the construction activity. The width, height, and gradient of a proposed culvert shall be such as to
pass the average historical low flow and spring flow without adversely altering flaw velocity. If the width of the culvert
is wider than the stream channel, the culvert shall include multiple boxes/pipes, baffles, benches and/or sills to
maintain the natural width of the stream channel. If multiple culvertslplpeslbarrels are used, low flows shall be
accommodated in one culvertlpipe and additional culvertsipipes shall be installed such that they receive only flows
above bar kful1.

CREEK CROSSING #1
3.2 Determine Low Flow/ Bankfull elevation: n/a
The single culvert will be buried 12" to comply with COE NWP 57 Regional Conditions.
As such, the vertical layout of the culvert looks like this:
CULVERT #1 PIPE DIA
PIPE SLOPE INV IN
Barrel 60
3.0% 310.1
Ex Ditch -
311.1
Pro Drive Elev.
326.0
TOP @ IN INV OUT TOP @ OUT
315.1 308.3 313.3
- 309.3 -
326.0
Using the SCS Method as described above for the proposed culverts, the following peak runoff elevations can be determ
STORM (24 hr)
Barrel
Flow (cfs)
Max Elevation
1-yr
22.81
312.47
2-yr
34.14
312.90
10-yr
67.77
313.99
25-yr
88.96
314.60
50-yr
106.39
315.08
100-yr
124.06
315.54
500-yr
167.81
316.63
1000-yr
186.78
317.09
(see attached hydrographs)

CROSSING 1
DEP Cary Type 1124-hr 1-yr24 hour Rainfall=2.86"
Prepared by Appian Consulting Engineers, PA Page 1
HydroCADO 8.00 s/n 003961 © 2006 HydroCAD Software Solutions LLC 6/1/2023
Subcatchment 1: Into Culvert 1
Inflow Hydrograph
Runoff = 22.81 cfs @ 12.09 hrs, Volume= 1.560 af, Depth= 0.87"
Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-120.00 hrs, dt= 0.05 hrs
Type II 24-hr 1-yr 24 hour Rainfall=2.86"
Area (ac) CN Description
8.000 55 Woods, Good, HSG B
0.500 85 Gravel roads, HSG B
4.000 61 >75% Grass cover, Good, HSG B
9.000 98 Paved roads
21.500
75 Weighted Average
12.500
Pervious Area
9.000
Impervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
15.0 1,700 1.89 Direct Entry, Site Flow
w
0
LL
Subcatchment 1: Into Culvert 1
Hydrograph
22.81cfs - -- -- -- --------------------
-- -- -- -- -- -- -----------
Type 11 24-hr 1�-yr 241 hour -
--',- ----=, --=, -- ---', -- I ---',---',---',---',---',---',---',---',---',--------- - ' - '- -
Rainf611�2,86"
Rpnoff Arep= 1.$OQ a'c
I unoff Volume=1.560 of
- - -- -- -- -- -- --- -' --! -Runoff Qepthr0187.'--
L-L--1--1--1--J--J--- -- Flow Length=1-,-70W _
L - L L - _ 1 1
-- - -- -- -- -- -- -- -- -- -- -- -- -- -- -- ---Tc=16.0-min--
CN=T5
L--
- - - - - - - - - - - - - - - - - - - - - - - - - - ----i---
5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 105 110 115 120
Time (hours)
— Runoff

CROSSING 1
DEP Cary Type 1124-hr 1-yr24 hour Rainfall=2.86"
Prepared by Appian Consulting Engineers, PA Page 2
HydroCADO 8.00 s/n 003961 © 2006 HydroCAD Software Solutions LLC 6/1/2023
Pond Cl: Culvert 1
Inflow Area =
21.500 ac,
Inflow Depth = 0.87"
for 1-yr 24 hour event
Inflow =
22.81 cfs @
12.09 hrs, Volume=
1.560 of
Outflow =
22.81 cfs @
12.09 hrs, Volume=
1.560 af, Atten= 0%, Lag= 0.0 min
Primary =
22.81 cfs @
12.09 hrs, Volume=
1.560 of
Routing by Stor-Ind method, Time Span= 5.00-120.00 hrs, dt= 0.05 hrs
Peak Elev= 312.47'@ 12.09 hrs
Device Routing Invert Outlet Devices
#1 Primary 311.10' 4.5' long Sharp -Crested Rectangular Weil End Contraction(s)
#2 Device 1 310.10' 60.0" x 60.0' long Barrel 1 (Low Flow)
RCP, square edge headwall, Ke= 0.500
Outlet Invert= 308.30' S= 0.0300 T Cc= 0.900
n= 0.012 Concrete pipe, finished
Primary OutFlowMax=22.41 cfs@ 12.09 hrs HW=312.45' (Free Discharge)
L1=Sharp-Crested Rectangular WeioWeir Controls 22.41 cfs @ 3.80 fps)
L2=Barrel 1 (Low Flow)(Passes 22.41 cfs of 43.47 cfs potential flow)
Pond Cl: Culvert 1
Hydrograph
74 22.81cfs - -- -- -- -- -- -- -- ----------------------------- ----- --
Inflow Area=2T.-500 aic -
?0 --',-----i-- ---- ---------------- ------ ---
Peak E.�IeV=312 AV
14 -- - ----+--+--+-- --+-- -- --------------------------i--- --i--- --
10 --L-L--L--1--1--1--L--1-- -- -- ---'------------------------L-----L--
6 --li - -- -- -- -- -- -----------------------------------li --li --li --
4 r r--r--T--T--T--T-- -- -- -- ------------------r--r--r--r--r--r--
11
2 --r r--r--r--r--r--r--r--r--r--r---i---i---i---i---i---r--r--r--r--r--r--
5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 105 110 115 120
Time (hours)
— Inflow
Primary

CROSSING 1
DEP Cary Type 1124-hr 2-yr 24 hour Rainfall=3.45"
Prepared by Appian Consulting Engineers, PA Page 3
HydroCADO 8.00 s/n 003961 © 2006 HydroCAD Software Solutions LLC 6/1/2023
Subcatchment 1: Into Culvert 1
Inflow Hydrograph
Runoff = 34.14 cfs @ 12.08 hrs, Volume= 2.269 af, Depth= 1.27"
Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-120.00 hrs, dt= 0.05 hrs
Type II 24-hr 2-yr 24 hour Rainfall=3.45"
Area (ac) CN Description
8.000 55 Woods, Good, HSG B
0.500 85 Gravel roads, HSG B
4.000 61 >75% Grass cover, Good, HSG B
9.000 98 Paved roads
21.500
75 Weighted Average
12.500
Pervious Area
9.000
Impervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
15.0 1,700 1.89 Direct Entry, Site Flow
w
0
LL
Subcatchment 1: Into Culvert 1
Hydrograph
i 34.14cfs - -- -- -- --------------- - -I--- ---------------------------I---
--L-L--1--1--1--J--�---1---1---1---1---1---L--L--L--1--1--1--�--�---I---I---
-- I ----------------------a pe-NII -err- r- 4 our--
ainf�l
----I---I------------------------------Rl�3�45..
-- ------------I-- -I-- - - - - --;-- -- ------I---
i --- ---- --I I-------------------------R -nof '-e-1= 1.$00ac--
-- _- r--T- -T- -T- - Iku o f-V��urir�e=2�
r-r--t--t--rt--------------------II-- 269-0 -
- - -- -- -- -- -----''I------------'II---' -- Runoff- - 44-- r11---
- ---+--+-- -- -- ---'' --- -- -Flow-Lenth_.'a-,70'--
� I I I I I I I I I I I I I I
Im_
I -- ----irr--- i-- --------I ---I ---I ---I --Ir---I ----------T-- ---- C1------I %---------IIIIII
5--------
TTTT rrTT
T-T--T--T--T---------T--T---
rrrrrT
--+--+---- --r-r--r--+--+--+--1-
-
-
Runoff
5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 105 110 115 120
Time (hours)

CROSSING 1
DEP Cary Type 1124-hr 2-yr 24 hour Rainfall=3.45"
Prepared by Appian Consulting Engineers, PA Page 4
HydroCADO 8.00 s/n 003961 © 2006 HydroCAD Software Solutions LLC 6/1/2023
Pond Cl: Culvert 1
Inflow Area =
21.500 ac,
Inflow Depth = 1.27"
for 2-yr 24 hour event
Inflow =
34.14 cfs @
12.08 hrs, Volume=
2.269 of
Outflow =
34.14 cfs @
12.08 hrs, Volume=
2.269 af, Atten= 0%, Lag= 0.0 min
Primary =
34.14 cfs @
12.08 hrs, Volume=
2.269 of
Routing by Stor-Ind method, Time Span= 5.00-120.00 hrs, dt= 0.05 hrs
Peak Elev= 312.90'@ 12.08 hrs
Device Routing Invert Outlet Devices
#1 Primary 311.10' 4.5' long Sharp -Crested Rectangular Weil End Contraction(s)
#2 Device 1 310.10' 60.0" x 60.0' long Barrel 1 (Low Flow)
RCP, square edge headwall, Ke= 0.500
Outlet Invert= 308.30' S= 0.0300 T Cc= 0.900
n= 0.012 Concrete pipe, finished
Primary OutFlowMax=33.49 cfs@ 12.08 hrs HW=312.88' (Free Discharge)
L1=Sharp-Crested Rectangular WeioWeir Controls 33.49 cfs @ 4.36 fps)
L2=Barrel 1 (Low Flow)(Passes 33.49 cfs of 63.13 cfs potential flow)
Pond Cl: Culvert 1
Hydrograph
i 34.14cfs - -- -- -- -- -- -- -- -- -
-------------- ---------I---
--I--- --
i --II-II--II-- --7 -- 7 -- III-- III-- III-- III-- III---------IIPeak-P.Iev,3-12.196 -
I I
T - T - - T - - T - - T - - T - - 7 - - 7 - - 7 - - 7 - - 7 T T - -
- - t - I - - I - - t - - t - - t - - t - - t - - t - - t - - t - - -
-L-LL1--1--1--L--1---------------------------------L-----L--
--II - -- -- -- -- --III --III -- III-- III-- III ---------------------------II --II --II --
{ --I - I--I--I--I--I--I-- I-
-I--I--I---------------------------I--I--I-_
i --F -T--T--T--T--T--7--7-----------------------------------T--r--
--T -T--T--T--T--T--7--T--T--T--T---------------------------T-----T--
5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 105 110 115 120
Time (hours)
— Inflow
Primary

CROSSING 1
DEP Cary Type 1124-hr 10-yr 24 hour Rainfall=5.01 "
Prepared by Appian Consulting Engineers, PA Page 5
HydroCADO 8.00 s/n 003961 © 2006 HydroCAD Software Solutions LLC 6/1/2023
Subcatchment 1: Into Culvert 1
Inflow Hydrograph
Runoff = 67.77 cfs @ 12.07 hrs, Volume= 4.403 af, Depth= 2.46"
Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-120.00 hrs, dt= 0.05 hrs
Type II 24-hr 10-yr 24 hour Rainfall=5.01"
Area (ac) CN Description
8.000 55 Woods, Good, HSG B
0.500 85 Gravel roads, HSG B
4.000 61 >75% Grass cover, Good, HSG B
9.000 98 Paved roads
21.500
75 Weighted Average
12.500
Pervious Area
9.000
Impervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
15.0 1,700 1.89 Direct Entry, Site Flow
Subcatchment 1: Into Culvert 1
Hydrograph
-- -- -- -- -- -- -- --- - --- -- -- -- -- -- -- --
67.77ds -T--T--r--r--r------------r-----r--r--r--T--T--r--r--r------I---
i --�,, -�,, -- -- --------------------�,,---T---e-HF241i�--1�- jr-24-hour
Y
-L--1--1--1--J--J---1---1---1---1---1---L--L--L--1--1--1--�--�---�---�---
Ralinfal1 5.011"
i --r -r--T--T--T--r--r------------r-----r--r--r--T--T--r--r--r------I---
i -----=--=--------------------------'-hutioff Area 21,500Q-aic-
i --� - -- -- -- -- --------------------I-Runoff-VOl-ume-=4.4d3-a# -
--T- T--T --T --�Iupoff-oe
--
--r-r--+--+--�__�__�___I---I---I---I---I---r--r--r--r--r--�--�--�---I---I---
TcT15.0 lmin
1 --r -r--T--T--r--r--r------------------r--r--r--T--T--T--,--,---I---I---
i --III- -III--- -- - - ICNI=7-15--
-r--+--+--4--1--I------------------r--r--r--r--r--4--1--I------I---
i --'r -'r --=I --=I -- 'I---'I---'I---I---I---I---I---I---'I----'r --'r --'r --'r --'I -- 'I-- 'I---I---I---
5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 105 110 115 120
Time (hours)
— Runoff

CROSSING 1
DEP Cary Type 1124-hr 10-yr 24 hour Rainfall=5.01 "
Prepared by Appian Consulting Engineers, PA Page 6
HydroCADO 8.00 s/n 003961 © 2006 HydroCAD Software Solutions LLC 6/1/2023
Pond Cl: Culvert 1
Inflow Area =
21.500 ac,
Inflow Depth = 2.46"
for 10-yr 24 hour event
Inflow =
67.77 cfs @
12.07 hrs, Volume=
4.403 of
Outflow =
67.77 cfs @
12.07 hrs, Volume=
4.403 af, Atten= 0%, Lag= 0.0 min
Primary =
67.77 cfs @
12.07 hrs, Volume=
4.403 of
Routing by Stor-Ind method, Time Span= 5.00-120.00 hrs, dt= 0.05 hrs
Peak Elev= 313.99'@ 12.07 hrs
Device Routing Invert Outlet Devices
#1 Primary 311.10' 4.5' long Sharp -Crested Rectangular Weil End Contraction(s)
#2 Device 1 310.10' 60.0" x 60.0' long Barrel 1 (Low Flow)
RCP, square edge headwall, Ke= 0.500
Outlet Invert= 308.30' S= 0.0300 T Cc= 0.900
n= 0.012 Concrete pipe, finished
Primary OutFlowMax=66.40 cfs@ 12.07 hrs HW=313.95' (Free Discharge)
L1=Sharp-Crested Rectangular WeioWeir Controls 66.40 cfs @ 5.52 fps)
L2=Barrel 1 (Low Flow)(Passes 66.40 cfs of 108.49 cfs potential flow)
Pond Cl: Culvert 1
Hydrograph
67.77 cfs
-r--T--T--T--7--7--r--r--r---I---I---I---I---I---I---I---I---r--r--r--
�I---I-Inflow Arella=�21-.-51100 arc -
I
I
--L-L--L--1--1--1--1--1--�--�--�---I---I ---I---I ---I---I---I---I---I---I---�--II-�--�{�--
IPeA-Etlwv=3-13:99� - i --r-r--r--T--T--T--7--7--r--r--r---
--I- - � -- � -- � -- � -- � -- � -- � -- �-- �-- �---II---II---II---II---II---II---II---II---Ii --li --� --
_r__r__T__T__T__7__7__1 _1- --_I___I___I__-I---I---I---I---I---r-----r--
I-- --r -r--r--T--T--T--7--7------------------------r--r--r--r-----r--
--I- - � -- � -- � -- � -- � -- � -- � -- �-- �-- �---II---II---II---II---II---II---II---II---Ii --li --� --
--Ir - IT -- IT ----
5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 105 110 115 120
Time (hours)
— Inflow
Primary

CROSSING 1
DEP Cary Type // 24-hr 25-yr 24 hour Rainfall=5.93"
Prepared by Appian Consulting Engineers, PA Page 7
HydroCADO 8.00 s/n 003961 © 2006 HydroCAD Software Solutions LLC 6/1/2023
Subcatchment 1: Into Culvert 1
Inflow Hydrograph
Runoff = 88.96 cfs @ 12.07 hrs, Volume= 5.774 af, Depth= 3.22"
Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-120.00 hrs, dt= 0.05 hrs
Type II 24-hr 25-yr 24 hour Rainfall=5.93"
Area (ac) CN Description
8.000 55 Woods, Good, HSG B
0.500 85 Gravel roads, HSG B
4.000 61 >75% Grass cover, Good, HSG B
9.000 98 Paved roads
21.500
75 Weighted Average
12.500
Pervious Area
9.000
Impervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
15.0 1,700 1.89 Direct Entry, Site Flow
Subcatchment 1: Into Culvert 1
Hydrograph
88.96 cfs
i --II, -, -- -- -----------------------I-T---e-U-2 —hr 25—yr24-hour -
I --r-r--T--T--�--�--�---I---I---I---� --I- �-r--r--T--Tp �- ,^'',I---I-(]--I---
i
I --T-T--T--T-- -- --------------I---------Rufioff Area=21 Z00-arc -
-
r--T--T--r--r--r---------------I---r--r--r--r--r--r
--,--,------I---
I --T-T--T--T-- -- -- ------------I ----- '-RgnoffTV01umv1==5I.7714^/ Of -
i - -r- r-- r--r-- r-- r-- r------------r r--r--r-- uI- Tf_0eI I `Ir4j, -
r r--T--T--r--r--r---I---I---I---r--I---r--r--
i --r-r--t--t------------ ------ ---------'r--r--0ow I;Len I gt=11,7O(Y--
r r--T--T--r--r--r---I---I---I---r--I---r--r--r--r--r--r--r--r---I---I---
i --r-r--t--t--rt-- -- --------- ---------'r--r--r--fi--t-Jc=45.0-min--
--r -r--+--+--+--+--+------------r--r--r--r--r--+--+--+--+-
i --r -r--t--t--r--r--r------------r--r--r--r--r--t--t--r--r--r------I---
--r -r--+--+--+--+--+------------r--r--r--r--r--+--+--+--+--+------I---
--+ -+--+--+--+--+--+------------------r--+--+--+--+--+--+--+------I---
5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 105 110 115 120
Time (hours)
— Runoff

CROSSING 1
DEP Cary Type // 24-hr 25-yr 24 hour Rainfall=5.93"
Prepared by Appian Consulting Engineers, PA Page 8
HydroCADO 8.00 s/n 003961 © 2006 HydroCAD Software Solutions LLC 6/1/2023
Pond Cl: Culvert 1
Inflow Area =
21.500 ac,
Inflow Depth = 3.22"
for 25-yr 24 hour event
Inflow =
88.96 cfs @
12.07 hrs, Volume=
5.774 of
Outflow =
88.96 cfs @
12.07 hrs, Volume=
5.774 af, Atten= 0%, Lag= 0.0 min
Primary =
88.96 cfs @
12.07 hrs, Volume=
5.774 of
Routing by Stor-Ind method, Time Span= 5.00-120.00 hrs, dt= 0.05 hrs
Peak Elev= 314.60'@ 12.07 hrs
Device Routing Invert Outlet Devices
#1 Primary 311.10' 4.5' long Sharp -Crested Rectangular Weil End Contraction(s)
#2 Device 1 310.10' 60.0" x 60.0' long Barrel 1 (Low Flow)
RCP, square edge headwall, Ke= 0.500
Outlet Invert= 308.30' S= 0.0300 T Cc= 0.900
n= 0.012 Concrete pipe, finished
Primary OutFlowMax=87.20 cfs@ 12.07 hrs HW=314.55' (Free Discharge)
L1=Sharp-Crested Rectangular WeioWeir Controls 87.20 cfs @ 6.08 fps)
L2=Barrel 1 (Low Flow)(Passes 87.20 cfs of 132.73 cfs potential flow)
N
U
3
0
LL
Pond Cl: Culvert 1
Hydrograph
88.96 cfs
I
I
I
I
I
I
I
--
-_I
I F
I
- --
_I
r--r--T--T--T--_T--_T--,--,--,---I---I---I---I---IIY--�yli---I---I---�--i
I
--
I
--
I
--
--
--
--
--
--
---IInflow
I I I I
r Arella=�21C.-511II0r aic -
--r--
i --li
�
1 - -T
r
i --r
r
i --r
--+
i --r
--+
- --
_I
-r--r--T--T--T----T--T--T--T------------------r--r--r----r--r--
_I
r--r--T--T--T--�--7--,--,--,---I-
-r--r--T--T--T--7--T--1--1--1---------------------------T-----T--
r-
-r--r--t--t
r-
-r--r--t--t
-r--r--t--t--t--+--+--+--+--+---------------------------+-----r--
-r--r--t-
-r--r--t--t--t--+--+--+--+--+---------------------------+-----r--
--
-r--T--T--T--T--T--T--
-r-
--
-T-
--
--t
-T-
-
-t-
--
--r--r--r--r--r-------
-T-
-t-
-t-
--
-T-
-r--r--r-
-r-
--
-T-
-r-
--
-T-
-r-
--
T-
-T-
-r-
-r-
---------II
-T--
-T--
-r--
-
r------------------r--r--r--r--r--r--
PeakP.[ev-_,344!160B--
I- I- I- I- r--r--r--�--T --r--
-I---I---I---I---
I---I---I---I---r--r--r--
------ - - - - -- ------ r-- - - -r --
-I---I---I---I---I---I---I---I---r--r--
r--
---------------r--r--r--r--r--r--
-
5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 105 110 115 120
Time (hours)
— Inflow
Primary

CROSSING 1
DEP Cary Type 1124-hr 50-yr 24 hour Rainfall=6.67"
Prepared by Appian Consulting Engineers, PA Page 9
HydroCADO 8.00 s/n 003961 © 2006 HydroCAD Software Solutions LLC 6/1/2023
Subcatchment 1: Into Culvert 1
Inflow Hydrograph
Runoff = 106.39 cfs @ 12.07 hrs, Volume= 6.916 af, Depth= 3.86"
Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-120.00 hrs, dt= 0.05 hrs
Type II 24-hr 50-yr 24 hour Rainfall=6.67"
Area (ac) CN Description
8.000 55 Woods, Good, HSG B
0.500 85 Gravel roads, HSG B
4.000 61 >75% Grass cover, Good, HSG B
9.000 98 Paved roads
21.500
75 Weighted Average
12.500
Pervious Area
9.000
Impervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
15.0 1,700 1.89 Direct Entry, Site Flow
Subcatchment 1: Into Culvert 1
Hydrograph
-r--r--r--r--r--7--7--7--
--
---li---li---li---li---li---li---Ir--Ir--Ir--Ir--
106.39ds
--'L
i --r
-L--L--L--
-+--+--r--+--+--+--+--+--+--+--+------------------i---it^-'-r--r--r--
--
--
--i--i--i--
--
Type-112+hr 04t 24 Mour-
I --li
- --
-- --
--
--
--
--
--
--
--
---------------
Ralfnfalk=6.6/i„-
i --r
- r--
r-- r--T
--T
--T
---T
-T
7--
--
----p--------`-,--------------i---i--
I --r
I --Ir
-+--+--r--+--+--+--�--�--�--�--�---I---I---b---
- r--
r-- r--r
--r
--r
---r
-r
7--;--;---li---li--1'11w1a„`Ty-
In-(-�-7�'�F I-}-�-I� I-R-----
��LIJ'i= r" " -
__''�r-ow-kwnh='r}or=
i --r
-r--r--r--r--r--r--r--r--r--r--r--r--r--r---i
- --
--
----------�------Tc=
--- i-- -� r-'r--
5
1-- ----------
i--�
--r
--Ir
---------------------------------------------EN_75
-r--r--r--r--r--r--r--r--r--r--r---i---i---i---i---i---i---r--r--r--r--
- --
-- --
--
--
--
--
--
,
----------------------------------li
- -
--
5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 105 110 115 120
Time (hours)
— Runoff

CROSSING 1
DEP Cary Type 1124-hr 50-yr 24 hour Rainfall=6.67"
Prepared by Appian Consulting Engineers, PA Page 10
HydroCADO 8.00 s/n 003961 © 2006 HydroCAD Software Solutions LLC 6/1/2023
Pond Cl: Culvert 1
Inflow Area =
21.500 ac,
Inflow Depth = 3.86"
for 50-yr 24 hour event
Inflow =
106.39 cfs@
12.07 hrs, Volume=
6.916 of
Outflow =
106.39 cfs @
12.07 hrs, Volume=
6.916 af, Atten= 0%, Lag= 0.0 min
Primary =
106.39 cfs @
12.07 hrs, Volume=
6.916 of
Routing by Stor-Ind method, Time Span= 5.00-120.00 hrs, dt= 0.05 hrs
Peak Elev= 315.08'@ 12.07 hrs
Device Routing Invert Outlet Devices
#1 Primary 311.10' 4.5' long Sharp -Crested Rectangular Weil End Contraction(s)
#2 Device 1 310.10' 60.0" x 60.0' long Barrel 1 (Low Flow)
RCP, square edge headwall, Ke= 0.500
Outlet Invert= 308.30' S= 0.0300 T Cc= 0.900
n= 0.012 Concrete pipe, finished
Primary OutFlowMax=104.35 cfs@ 12.07 hrs HW=315.02' (Free Discharge)
L1=Sharp-Crested Rectangular WeioWeir Controls 104.35 cfs @ 6.48 fps)
L2=Barrel 1 (Low Flow)(Passes 104.35 cfs of 147.84 cfs potential flow)
w
3
O
LL
Pond Cl: Culvert 1
Hydrograph
� 106.39cfs -Ir --i --i --i --i --i --i --i --i --*--r--r--r--r--r--r--r--Y--Y--*--
InfFovtr Atea=24.5-00 -a1c -
ev al 5 10
-+--+------------------+--+--+--+--+--+--+--+--+--+--+--
4-4 � -�
� F--F--rrrrrrrrrrrrrrrrTT-_T--
-r--r--r--r--r--r--r--r--r--r--r--r--r--r--r--r--r--r--r--r--r--
--�i-�i--�i--�i--�i--�i--�i--�i--�i--�i--�i--�i--�i--�i--�i--�i--�i--�i--�i--�i--it--li--
--r -r--r--r--r--r--r--r--r--r--r--t--r--r--r--r--r--r--r--r--r--t--
--�i-�i--�i--�i--�i--�i--�i--�i--�i--�i--�i--�i--�i--�i--�i--�i--�i--�i--�i--�i--it--li--
5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 105 110 115 120
Time (hours)
— Inflow
Primary

CROSSING 1
DEP Cary Type 1124-hr 100-yr 24 hour Rainfall=7.41 "
Prepared by Appian Consulting Engineers, PA Page 11
HydroCADO 8.00 s/n 003961 © 2006 HydroCAD Software Solutions LLC 6/1/2023
Subcatchment 1: Into Culvert 1
Inflow Hydrograph
Runoff = 124.06 cfs @ 12.07 hrs, Volume= 8.085 af, Depth= 4.51"
Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-120.00 hrs, dt= 0.05 hrs
Type II 24-hr 100-yr 24 hour Rainfall=7.41"
Area (ac) CN Description
8.000 55 Woods, Good, HSG B
0.500 85 Gravel roads, HSG B
4.000 61 >75% Grass cover, Good, HSG B
9.000 98 Paved roads
21.500
75 Weighted Average
12.500
Pervious Area
9.000
Impervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
15.0 1,700 1.89 Direct Entry, Site Flow
Subcatchment 1: Into Culvert 1
Hydrograph
124.06cfs- -- -- -- -- -- -- -- -- -- ---------------------------------
Type fl 24�hr,100-y�r, 4 -our
-
Rain
,fall=7;.41..
+ - - + - - 4 - - 4 - - 4 - - I - - I - - -I-
Ru nolff Area=21,500 ac
--r -r--r--r--r--r--r--r--r--r--r--r--r--r--r--- I --- I --- I --- --- I---I---r--
Runoff Volume=8.085 of
--r -r--r--r--r--r--r--r--r--r--r--r--r--r--r---i---i---i---r--r--r--r--
Rundff Deoth=4.51,"
FlOW L6nothr1,',700'
,---,---,---,---��,---��,---Tc------'�` -i'�- -
Ili--------------------------'iit��=ia2-
--L-L--L--L--1--1--1--1--1--1----------------------------------�---
5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 105 110 115 120
Time (hours)
— Runoff

CROSSING 1
DEP Cary Type 1124-hr 100-yr 24 hour Rainfall=7.41 "
Prepared by Appian Consulting Engineers, PA Page 12
HydroCADO 8.00 s/n 003961 © 2006 HydroCAD Software Solutions LLC 6/1/2023
Pond C1: Culvert 1
Inflow Area =
21.500 ac,
Inflow Depth = 4.51"
for 100-yr 24 hour event
Inflow =
124.06 cfs@
12.07 hrs, Volume=
8.085 of
Outflow =
124.06 cfs @
12.07 hrs, Volume=
8.085 af, Atten= 0%, Lag= 0.0 min
Primary =
124.06 cfs @
12.07 hrs, Volume=
8.085 of
Routing by Stor-Ind method, Time Span= 5.00-120.00 hrs, dt= 0.05 hrs
Peak Elev= 315.54'@ 12.07 hrs
Device Routing Invert Outlet Devices
#1 Primary 311.10' 4.5' long Sharp -Crested Rectangular Weil End Contraction(s)
#2 Device 1 310.10' 60.0" x 60.0' long Barrel 1 (Low Flow)
RCP, square edge headwall, Ke= 0.500
Outlet Invert= 308.30' S= 0.0300 T Cc= 0.900
n= 0.012 Concrete pipe, finished
Primary OutFlowMax=121.73 cfs@ 12.07 hrs HW=315.48' (Free Discharge)
L1=Sharp-Crested Rectangular WeioWeir Controls 121.73 cfs @ 6.84 fps)
L2=Barrel 1 (Low Flow)(Passes 121.73 cfs of 160.42 cfs potential flow)
Pond C1: Culvert 1
Hydrograph
124.06cfs -li --' --' --' --' --' --' --' --' --' --' --' --' --' --' --' --' --' --' --' --
-L--L--L--L--L--L--L--L--L--L--1--L--L--L--L--L--L--L--L--L--L--
Inflow Areal-21.500 arc
--L -L--L--L--L--L--L--L--L--L--L--1--L--L--L--L--L--L--L--L--L--L--
- IPeaI
--r -r--r--r--r--r--r--r--r--r--r--r--r--r--r--r--r--r--r--t--t--t--
--r -r--r--r--r--r--r--r--r--r--r--r--r--r--r--r--r--r--r--r--r--t--
F- F- - - r---rrrrrrrrrrrrrrrrT--7--T
- - L - L - - L - - L - - L - - L - - L - - L - - L - - L - - L - - L - - L - - L - - L - - L - - L - - L - - L - - L - - L
--L- L--L--
------------------------------------�--
5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 105 110 115 120
Time (hours)
— Inflow
Primary

CROSSING 1
DEP Cary Type // 24-hr 500-yr 24 hour Rainfall=9.22"
Prepared by Appian Consulting Engineers, PA Page 13
HydroCADO 8.00 s/n 003961 © 2006 HydroCAD Software Solutions LLC 6/1/2023
Subcatchment 1: Into Culvert 1
Inflow Hydrograph
Runoff = 167.81 cfs @ 12.07 hrs, Volume= 11.027 af, Depth= 6.15"
Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-120.00 hrs, dt= 0.05 hrs
Type II 24-hr 500-yr 24 hour Rainfall=9.22"
Area (ac) CN Description
8.000 55 Woods, Good, HSG B
0.500 85 Gravel roads, HSG B
4.000 61 >75% Grass cover, Good, HSG B
9.000 98 Paved roads
21.500
75 Weighted Average
12.500
Pervious Area
9.000
Impervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
15.0 1,700 1.89 Direct Entry, Site Flow
N
1
0
LL
Subcatchment 1: Into Culvert 1
Hydrograph
167.81 cfs
--i
---T--T-- --T-- --T-- -- -- -- -- -Typip 11-24,-hr-5Qtiyir�4-6o-"r-
--T-T--T--T--T--T--T--�--�--�--,--r--r--r--r--r--r--r---r--r--r--r--
r-T--T----+--+--+-- ---------------------------Rein,fal�=_9.2Z'
--' - -- -- -- -- -- -- -- -- -- --------'Runo fArQa=21,50o-atc-
-- -- IRUnoff- Volume=l t.027 ,af -
--j - j -- j -- j -- j -- j -- j -- -- -- -- --------�---I Rttndff Depth-G.1F
--T- T--T--T--T--T- -T---T -T---------------''Fl6v -L n hr�;T60`-
r r--r--r--r--r--r--rt--rt--rt--y--y------------------1---
-- - -- -- -- -- -- -- -- -- -- --------------------------M=7
--�- - -- r -- -- -- -- -- -- ------------------------------------li --
--Ir - -- -- -- -- -- -- -- ------------------------------------li --
--r r--r--r--r--r--r--r--r--r--r--r--r--r--r------------r--r--r--r--
5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 105 110 115 120
Time (hours)
— Runoff

CROSSING 1
DEP Cary Type // 24-hr 500-yr 24 hour Rainfall=9.22"
Prepared by Appian Consulting Engineers, PA Page 14
HydroCADO 8.00 s/n 003961 © 2006 HydroCAD Software Solutions LLC 6/1/2023
Pond Cl: Culvert 1
Inflow Area =
21.500 ac,
Inflow Depth = 6.15"
for 500-yr 24 hour event
Inflow =
167.81 cfs@
12.07 hrs, Volume=
11.027 of
Outflow =
167.81 cfs@
12.07 hrs, Volume=
11.027 af, Atten= 0%, Lag= 0.0 min
Primary =
167.81 cfs@
12.07 hrs, Volume=
11.027 of
Routing by Stor-Ind method, Time Span= 5.00-120.00 hrs, dt= 0.05 hrs
Peak Elev= 316.63'@ 12.07 hrs
Device Routing Invert Outlet Devices
#1 Primary 311.10' 4.5' long Sharp -Crested Rectangular Weil End Contraction(s)
#2 Device 1 310.10' 60.0" x 60.0' long Barrel 1 (Low Flow)
RCP, square edge headwall, Ke= 0.500
Outlet Invert= 308.30' S= 0.0300 T Cc= 0.900
n= 0.012 Concrete pipe, finished
Primary OutFlowMax=164.82 cfs@ 12.07 hrs HW=316.56' (Free Discharge)
L1=Sharp-Crested Rectangular WeioWeir Controls 164.82 cfs @ 7.64 fps)
L2=Barrel 1 (Low Flow)(Passes 164.82 cfs of 188.06 cfs potential flow)
Pond Cl: Culvert 1
Hydrograph
- - - - - - - - - - rnflw Are 2'C -600 aic -
--r -
r--r--r--r--r--r--r--r--r--r--r--r--r--r--r--r--r--r--r--r--r--
-- - -- -- -- -- -- -- -- -- -- --+--+--Peak 81ev-a166"
T--T--r--r--r--r--r--r--r--r--r--r--r--r--r--r--r--r--T--T--T
--
--r -r--r--r--r--r--r--r--r--r--r--+--t--t--t--t--t--t--t--t--t--t--
_-L -L--L--L__L__L__L__L__L__L__L__1__L__L__L__L__L__L__L__1__1__1--
--r r-
-r--r--r--r--r--r--r--r--r--r--r--r--r--r--r--r-- r-- r-- r - -r --
5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 105 110 115 120
Time (hours)
— Inflow
Primary

CROSSING 1
DEP Cary Type 1124-hr 1000-yr 24 hour Rainfall=10.00"
Prepared by Appian Consulting Engineers, PA Page 15
HydroCADO 8.00 s/n 003961 © 2006 HydroCAD Software Solutions LLC 6/1/2023
Subcatchment 1: Into Culvert 1
Inflow Hydrograph
Runoff = 186.78 cfs @ 12.07 hrs, Volume= 12.322 af, Depth= 6.88"
Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-120.00 hrs, dt= 0.05 hrs
Type II 24-hr 1000-yr 24 hour Rainfall=10.00"
Area (ac) CN Description
8.000 55 Woods, Good, HSG B
0.500 85 Gravel roads, HSG B
4.000 61 >75% Grass cover, Good, HSG B
9.000 98 Paved roads
21.500
75 Weighted Average
12.500
Pervious Area
9.000
Impervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
15.0 1,700 1.89 Direct Entry, Site Flow
Subcatchment 1: Into Culvert 1
Hydrograph
200 I - -- I -- 1
186.78cfs - -- ----------------------------------- —Runoff
190 -----------------------' ---' ---' ---'---'---'---------------------------'---
180 -- L L L -- ----L_L_L_--TType,11�4= r=fi000=�r �4 1
170 =
- - f1
160 ---L--L--L--1--1--1--1--1--1-- --------------'---iRcl n �H=1QM' -
140 --+-+--+--+--+--+--+--+--+--+--+--+-----Runoff
--I��nQfFArga=21T $00 c1c -
r�
130 --r-+--+--r--+--+--+-- -- -- -- ------'unQ Volurpe=13#Of -
120--r-+--+--r--+--+--+--+--+--+--+--+---------------i-------i----
ff
0 100 --T-T-- T--T-- T-- T-- T-- T-- T-- T-- T--T------I---I-flow Length=9;70'--
a 90 --r - 1 --T-- r -- 1 -- 1 -- 1 -- 1 -- 1 -- 1 -- 1-- 1-------------------T--,----f1----,---
80 --r -, --, -- --, --, --, -- -- -- -- -----,---,------------_LC=17/.�S,inir--
70 - - II- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -IIC W7- I5 -
60 --- - -- -- -- -- -- -- -- -- -- --------------------------------li --
50 --- - -- -- -- -- -- -- -- -- -- --------------------------------li --
40 --'---------------------' ---' ---' ---'---'---'---------------------------'---
30 -- I L-L--L--L--1--1--1--1--1--1-- -- ---'---------------------------'---
20 -- - -- -- -- -- -- -- -- -- -- -- ---------------------------------
5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 105 110 115 120
Time (hours)

CROSSING 1
DEP Cary Type 1124-hr 1000-yr 24 hour Rainfall=10.00"
Prepared by Appian Consulting Engineers, PA Page 16
HydroCADO 8.00 s/n 003961 © 2006 HydroCAD Software Solutions LLC 6/1/2023
Pond C1: Culvert 1
Inflow Area =
21.500 ac,
Inflow Depth = 6.88"
for 1000-yr 24 hour event
Inflow =
186.78 cfs@
12.07 hrs, Volume=
12.322 of
Outflow =
186.78 cfs @
12.07 hrs, Volume=
12.322 af, Atten= 0%, Lag= 0.0 min
Primary =
186.78 cfs @
12.07 hrs, Volume=
12.322 of
Routing by Stor-Ind method, Time Span= 5.00-120.00 hrs, dt= 0.05 hrs
Peak Elev= 317.09'@ 12.07 hrs
Device Routing Invert Outlet Devices
#1 Primary 311.10' 4.5' long Sharp -Crested Rectangular Weil End Contraction(s)
#2 Device 1 310.10' 60.0" x 60.0' long Barrel 1 (Low Flow)
RCP, square edge headwall, Ke= 0.500
Outlet Invert= 308.30' S= 0.0300 T Cc= 0.900
n= 0.012 Concrete pipe, finished
Primary OutFlowMax=183.52 cfs@ 12.07 hrs HW=317.01' (Free Discharge)
L1=Sharp-Crested Rectangular WeioWeir Controls 183.52 cfs @ 7.95 fps)
L2=Barrel 1 (Low Flow)(Passes 183.52 cfs of 198.47 cfs potential flow)
Pond C1: Culvert 1
Hydrograph
200
190
186.78cfs]-,---,---,---,---,---,---,---,---,---,----------------------------,--
--- cfs-
--'---'---'---'---'---'---'---'---'---'---'---'---'---'---'---'----'---'--'---
180
--'
--'
--'
+
--'
L
--'
--'
--'
--'
--' --' - -- - ---
L/wAiva 14.5100Aa3
170
--
---
-
- -
-L--L--L--L--L--
--L--Iftfl s-
160
--�
-�--�--L--L--L--L--L--L--L--L--+--+--
Q+-- +--+ + �-
ti
150
-
- --
--
--
--
--
--
--
-- ----+--+-- -Qia 64_=1 J_a --
130
--+
-+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--
N 120
--+
-+--+--r--r--r--r--r--r--r--r--+--+--+--+--+--+--+--+--+--+--+--
3 100
0
--
- -----r--r--r--r--r--r--r--r--T--T--T--T--T--T--T--T--T--T--T--
LL 90
�
I
�
�
I
I
I
I
I
I I I I I I I I I I I I I 1
70
--,-
-1---,---,---,---,---,---,---,---,---,---,----------------------------,--
60
---
----
--
--
--
--
--
--
-- -- -- -- -- -- -- -- -- -- -- -- -- --
50
--'-
-'---'--'---'---'---'---'---'---'---'---'---'---------------------------'---
40
--L
-L--'---'---'---'---'---'---'---'---'---'---'---------------------------'---
30
--
-IL--IL--L--L--L--L--L--L--L--L--1--L--L--L--L--L--L--L--1--1--T--
20
--+
-+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--
10
--+-
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--
0
5 10
15
20
25
30
35
40
45
50 55 60 65 70 75 80 85 90 95 100 105 110 115 120
Time (hours)
— Inflow
Primary

CREEK CROSSING #2
CALCULATIONS

CULVERT CALCULATIONS
Project: DEP Cary Triangle Expressway
Description: CREEK CROSSING #2
Designer: dcr
Date: 5/15/2023
1.1 Based on NCDOT topo, the contributing watershed for this culvert is approximately 125 acres (see attached Runoff Map).
1.2 The watershed characteristics can be approximated as follows:
Total;
ACRES
CN
DESCRIPTION
15.0
55
Woods, Good, HSG B
0.3
85
Gravel Roads, HSG B
6.0
61
>75% Grass cover good HSG B
3.0
98
Paved Roads
2.5
1
Open Water (Ponds)
26.0
65
Ex 2-ac lots, 12% imp HSG B
67.0
70
FUT 0.5ac lot 25% imp HSG B
5.2
75
FUT 0.25ac lot 25% imp HSG B
125.0
66
Weighted CN
1.3 Using the SCS Method and rainfall information from NOAA at this location, the peak runoff rates are as follows:
STORM (24 hr)
FLOW (cfs)
1-yr
37.18
2-yr
69.13
10-yr
177.46
25-yr
250.94
50-yr
313.44
100-yr
378.22
500-yr
543.36
1000-yr
616.55
(see attached hydrographs)

CREEK CROSSING #2
Upstream of this creek crossing is an existing 8'x6' box culvert and 72" directing runoff from under 1-540. The proposed culvert will
provide the approximate opening size (equivalent sf) as the two upstream culverts. Although not a primary design criteria, these
culverts will safely pass the 100 year storm without impoundment of water (see attached hydrographs). Triple 72" RCPs are
proposed at this location.
Area of
Opening (sf)
Ex Upstream 8'x6' RCBC: 48
Ex Upstream 72" RCP: 28
Total Ex Upstream Opening: 76
Proposed (3) 72" RCP*: 84
*Not including area obstructed by buring culvert 12" per NWP57
3.1 Per US COE NWP 57, Regional Conditions for Culvert:
9. Culvert Placement. For all NWPs that allow for culvert placement, the following
conditions shall be applied:
a. For all NWPs that involve the constructioNinstallation of culverts, measures shall be included in the
construction/installation that will promote the safe passage of fish and other aquatic organisms
ss
Placement of culverts and other structures in streams shall be below the elevation of the streambed by one foot for
all culverts with a diameter greater than 48 inches, and 20% of the culvert diameter for culverts having a diameter
less than or equal to 48 inches. If the culvert outlet is submerged within a pool or scour hole and designed to provide
for aquatic passage, then culvert burial into the streambed is not required.
Culvert burial is not required for structures less than 72 inch diameterlwidth, where the slope of the culvert will be
greater than 2.5%, provided that all alternative options for flattening the slope have been investigated and aquatic
life movement/connectivity has been provided when possible (e.g., rock ladders, cross vanes, sills, baffles etc.).
Culvert burial is not required when bedrock is present in culvert locations.
Installation of culverts in wetlands shall ensure continuity of water movement and be designed to adequately
accommodate high water or flood conditions. When roadways, causeways, or other fill projects are constructed
across FEMA-designated floodways or wetlands, openings such as culverts or bridges shall be provided to maintain
the natural hydrology of the system as well as prevent constriction of the floodway that may result in destabilization
of streams or wetlands.
A waiver from the depth specifications in this condition may be requested, in writing, by the permittee and issued by
the Corp. This waiver request must be specific as to the reasons(s) for the request. The waiver will be issued if it
can be demonstrated that the proposed design would result in less impacts to the aquatic environment. Culverts
placed across wetland fills purely for the purposes of equalizing surface water do not have to be buried, but the
culverts must be of adequate size and/or number to ensure unrestricted transmission of water.
b. Bank -full flows (or less) shall be accommodated through maintenance of the existing bank -full channel cross
sectional area. Additional culverts or culvert barrels at such crossings shall be allowed only to receive bank -full
flows.

CREEK CROSSING #2
Approach ER
Roadway
Ouluertburied
Bm&RIlt belowsmeambed
m appropriate
depth (ifiequned),
Bafli strna
VlQukage 6ottvm
c. Culverts shall be designed and installed in such a manner that the original stream profiles are not altered and
allow for aquatic life movement during low flows. The dimension, pattern, and profile of the stream above and below
a pipe or culvert shall not be modified by widening the stream channel or by reducing the depth of the stream in
connection with the construction activity. The width, height, and gradient of a proposed culvert shall be such as to
pass the average historical low flow and spring flow without adversely altering flow velocity. If the width of the culvert
is wider than the stream channel, the culvert shall include multiple boxes/pipes. baffles, benches and/or sills to
maintain the natural width of the stream channel. If multiple culvertslpipeslbarrels are used, low flows shall be
accommodated in one culvertlpipe and additional culverts/pipes shall be installed such that they receive only flows
above bankfull.
3.2 Determine Low Flow/ Bankfull elevation:
U0IINIU11 cICVOLIVII VVO U-1 IIIIIICU UY LI 101-OIIu-Cl I Vl, Gllu U-1 IIIIIICU LV - Lllc GI.l I.11 VAIII10- 1-Ylr G 111 . 1III Iul LIIL u-11 WILII O
5 feet bottom width. The bank -full elevation is approximately 2.2 feet, so the secondary barrels will be this distance above the
stream elevation of the first barrel such that Barrels #2 and #3 receive only flows above bankfull, per COE NWP 57 Regional
Conditions.
As such, the vertical layout of the culvert looks like this:
ex bottom strearr
111106I10LYAW 010E
= PRO TOP RCP IN
CULVERT #2
PIPE DIA
PIPE SLOPE
INV IN
TOP @ IN
INV OUT
TOP @ OUT
Barrel
72
0.62%
294.4
300.4
294.0
300.0
Barrel
72
1.0%
297.6
303.6
296.95
303.0
Barrel
72
1.0%
297.6
303.6
296.95
303.0
Ex Ditch
-
295.4
-
295.0
-
Pro Drive Elev.
311.0
311.0
Using the SCS Method as described above for the proposed culverts, the following peak runoff elevations can be determined:
STORM (24 hr)
Barrel #1
Flow (cfs)
Barrels 2 & 3
Flow (cfs)
Total
Flow (cfs)
Max
Elevation
1-yr
37.18
-
37.18
297.60
2-yr
59.08
10.05
69.13
298.28
10-yr
110.02
67.44
177.46
299.53
25-yr
140.09
110.85
250.94
300.19
50-yr
164.11
149.33
313.44
300.70
100-yr
187.77
190.45
378.22
301.20
500-yr
241.63
301.73
543.36
302.39
1000-yr
261.711
354.84
1 616.55
1302.92
(see attached hydrographs)

CROSSING 2
DEP Cary Type 1124-hr 1-yr24 hour Rainfall=2.86"
Prepared by Appian Consulting Engineers, PA Page 1
HydroCADO 8.00 s/n 003961 © 2006 HydroCAD Software Solutions LLC 6/1/2023
Subcatchment 2: Into Culvert 2
Inflow Hydrograph
Runoff = 37.18 cfs @ 12.31 hrs, Volume= 4.995 af, Depth= 0.48"
Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-120.00 hrs, dt= 0.05 hrs
Type II 24-hr 1-yr 24 hour Rainfall=2.86"
Area (ac) CN Description
15.000
55
Woods, Good, HSG B
0.300
85
Gravel roads, HSG B
6.000
61
>75% Grass cover, Good, HSG B
3.000
98
Paved roads
2.500
1
Open Water- Ponds
26.000
65
Ex 2 acre lots, 12% imp, HSG B
67.000
70
FUT 1/2 acre lots, 25% imp, HSG B
5.200
75
FUT 1/4 acre lots, 38% imp, HSG B
125.000
66
Weighted Average
100.154
Pervious Area
24.846
Impervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
30.0 3,500 1.94 Direct Entry, Site Flow
Subcatchment 2: Into Culvert 2
Hydrograph
37.18 cfs
i 1--1--1--J--J---1---1---1---1---1---L--L--L--1--1--1--�--�---'---'---
i 1
--L-L--1--1--1--J--�---1---1---1---1---1---L--L--L--1--1----�--�- �---�---
- ---+--+-- -- -- ---' _Txpe_11,�4-hr-1' x�2'h��our--
- - -- -- -- -- -----------------'---' --�- ---RainftH6_
-r--+--+------------------------ un�-moo#-`,^rya=mlQwQQO(�C�,�ef--
i =-r-
r--t--t--rt--y---------------r---- jf�-_/f-Tulmm'-6= ',995-�+--
-r -r--r--r--r--r--r---------r--r--i--
r-r--T--T-- r--r-Ruho�De0th-0.U"__
-- - -- -- -----li---li------------�i-----li -- - -- ii�-/ rr
-Flo
- -- -- ---
--------------i- - -;- -, - - -; --; --; -- --T -7rE-3Q.0-min- -
--L L--1--1--1--J-----1---1---1---1---1---L--L--L--1--1--1-----SLNIi=66__
L--1--1--1--J--J---1---1---1---1---1---L--L--L--1--1--1--�--�---�---�---
i----------------------------------------------------�---
--� ---+--+--------------------------I--I--I--I--4---4---4------�---
5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 105 110 115 120
Time (hours)
— Runoff

CROSSING 2
DEP Cary Type 1124-hr 1-yr24 hour Rainfall=2.86"
Prepared by Appian Consulting Engineers, PA Page 2
HydroCADO 8.00 s/n 003961 © 2006 HydroCAD Software Solutions LLC 6/1/2023
Pond C2: Culvert 2
Inflow Area =
125.000 aq
Inflow Depth = 0.48"
for 1-yr 24 hour event
Inflow =
37.18 cfs @
12.31 hrs, Volume=
4.995 of
Outflow =
37.18 cfs @
12.31 hrs, Volume=
4.995 af, Atten= 0%, Lag= 0.0 min
Primary =
37.18 cfs @
12.31 hrs, Volume=
4.995 of
Routing by Stor-Ind method, Time Span= 5.00-120.00 hrs, dt= 0.05 hrs
Peak Elev= 297.61'@ 12.31 hrs
Device Routing
Invert
Outlet Devices
#1 Primary
295.40'
72.0" x 65.0' long Barrel 1 (Low Flow)
RCP, square edge headwall, Ke= 0.500
Outlet Invert= 295.00' S= 0.0062 T Cc= 0.900
n= 0.012 Concrete pipe, finished
#2 Primary
297.60'
72.0" x 65.0' long Barrel 2RCP, square edge headwall, Ke= 0.500
Outlet Invert= 296.95' S= 0.0100'/' Cc= 0.900
n= 0.012 Concrete pipe, finished
#3 Primary
297.60'
72.0" x 65.0' long Barrel 3RCP, square edge headwall, Ke= 0.500
Outlet Invert= 296.95' S= 0.0100'/' Cc= 0.900
n= 0.012 Concrete pipe, finished
Primary OutFlowMax=37.02 cfs@ 12.31 hrs HW=297.60' (Free Discharge)
1=Barrel 1 (Low Flow)(Barrel Controls 37.02 cfs @ 5.85 fps)
2=Barrel 2 (Barrel Controls 0.00 cfs @ 0.17 fps)
3=Barrel 3 (Barrel Controls 0.00 cfs @ 0.17 fps)
Pond C2: Culvert 2
Hydrograph
l0--I--- -- -- -- -- -- -- -- -- -- -- -- -- -- -- ---I-- -----------I---
38 37.18 cfs
-L--L--L--L--1--1--1--1--1--1--1--1--1--1--J--�--�--�--�---I---
36 --�-L--L--L--L--L--1--1--1--1--1--1- 1--1--11--J-_-�--�- �--�---I---
34 -- - -- -- -- -- -- ----+--+--+-_ nf10WArea-a2&000-aC--
a
-- - = y-- 30 --I+ - -- --+-- ----+--+--+--+--+-- -- --+_ ev+
28 --r-r--r--r--r--r--+--+--+--+--+--rt--rt--+-- --rt--y--y--y--y--y---I---
?6 r r--r--r--r--r--r--r--r--r--r--r--r--r--r--r--r--r--r--r--r---I---
I I
?4 � r--r--r--r--r--T--T--T--T--T--�--�--T--�--�--�--�--�--T--T---I---
?2 T - - T - - T - - T - - T - - T - - T - - T - - T - - T - - T - - T - - T - - T-I-
)Q -- T -- T -- T -- T -- T -- T -- -- -- -- -- -- -- -- -- -I -- -----------I---
18
10 --L L--L--L--L--L--1--1--1--1--L--1--1--1----1--J-- ----J--J---I---
6 -- -- -- -- -- -- ----+--+--+-- -- --+-- -- -- -- -- -- -- ---I---
4 - - + - - - + - - + - - + - - + - - + - - + - - + - - + - - + - - + - - + - - + - - + - - + - -
2 --r -r-- +--r--r--+--+--+--+--+----+--+-- -- ----1--1-- -- ---I---
5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 105 110 115 120
Time (hours)
— Inflow
Primary

CROSSING 2
DEP Cary Type 1124-hr 2-yr 24 hour Rainfall=3.45"
Prepared by Appian Consulting Engineers, PA Page 3
HydroCADO 8.00 s/n 003961 © 2006 HydroCAD Software Solutions LLC 6/1/2023
Subcatchment 2: Into Culvert 2
Inflow Hydrograph
Runoff = 69.13 cfs @ 12.29 hrs, Volume= 8.055 af, Depth= 0.77"
Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-120.00 hrs, dt= 0.05 hrs
Type II 24-hr 2-yr 24 hour Rainfall=3.45"
Area (ac) CN Description
15.000
55
Woods, Good, HSG B
0.300
85
Gravel roads, HSG B
6.000
61
>75% Grass cover, Good, HSG B
3.000
98
Paved roads
2.500
1
Open Water- Ponds
26.000
65
Ex 2 acre lots, 12% imp, HSG B
67.000
70
FUT 1/2 acre lots, 25% imp, HSG B
5.200
75
FUT 1/4 acre lots, 38% imp, HSG B
125.000
66
Weighted Average
100.154
Pervious Area
24.846
Impervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
30.0 3,500 1.94 Direct Entry, Site Flow
Subcatchment 2: Into Culvert 2
Hydrograph
69.13 cfs
i --L-L--1--1--1-- J--J------------- ------'�--�-T-P-e-H 2--4m1w 2- r-24hou.r,---
-
'''''-T--T_TT- T-- T-- T - -T--
--anal 3� a
--}-}--T--T------------I,1upofA+rqa=1�5.000 a'q--
-- -- -- -- ---uo#f� -�tuxe:,05-a# -
--L-L--1--1--1--J--J------------------ L--L-RunofUDepthr0.,7 "--
-+-+--+--+-- -- -- r-flow-Le ng!h=3, 0Q'
i --I ---+--+-- -- -----------I'i---+--+--+-- ----+--+_'+C_,VOA Q
i --+ L--1--1--1--J--J---1---1---1---1---1---L--L--L--1--1--1-- ---7---i---
5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 105 110 115 120
Time (hours)
— Runoff

CROSSING 2
DEP Cary Type 1124-hr 2-yr 24 hour Rainfall=3.45"
Prepared by Appian Consulting Engineers, PA Page 4
HydroCADO 8.00 s/n 003961 © 2006 HydroCAD Software Solutions LLC 6/1/2023
Pond C2: Culvert 2
Inflow Area =
125.000 aq
Inflow Depth = 0.77"
for 2-yr 24 hour event
Inflow =
69.13 cfs @
12.29 hrs, Volume=
8.055 of
Outflow =
69.13 cfs @
12.29 hrs, Volume=
8.055 af, Atten= 0%, Lag= 0.0 min
Primary =
69.13 cfs @
12.29 hrs, Volume=
8.055 of
Routing by Stor-Ind method, Time Span= 5.00-120.00 hrs, dt= 0.05 hrs
Peak Elev= 298.28'@ 12.29 hrs
Device Routing
Invert
Outlet Devices
#1 Primary
295.40'
72.0" x 65.0' long Barrel 1 (Low Flow)
RCP, square edge headwall, Ke= 0.500
Outlet Invert= 295.00' S= 0.0062 T Cc= 0.900
n= 0.012 Concrete pipe, finished
#2 Primary
297.60'
72.0" x 65.0' long Barrel 2RCP, square edge headwall, Ke= 0.500
Outlet Invert= 296.95' S= 0.0100'/' Cc= 0.900
n= 0.012 Concrete pipe, finished
#3 Primary
297.60'
72.0" x 65.0' long Barrel 3RCP, square edge headwall, Ke= 0.500
Outlet Invert= 296.95' S= 0.0100'/' Cc= 0.900
n= 0.012 Concrete pipe, finished
Primary OutFlowMax=68.77 cfs@ 12.29 hrs HW=298.27' (Free Discharge)
1=Barrel 1 (Low Flow)(Barrel Controls 59.08 cfs @ 6.47 fps)
2=Barrel 2 (Inlet Controls 4.85 cfs @ 2.79 fps)
3=Barrel 3 (Inlet Controls 4.85 cfs @ 2.79 fps)
Pond C2: Culvert 2
Hydrograph
69.13 cfs
{i-------- ---
i --I� - --i -- -- -- -- -- -- -- -- -- �f1i iow,Ar"= 12.5.V00-QV--
-
r--r-- r--r-- r-- r--r-- r-- r--r-- r-- r-- r -�iGak f:1r-`�=w$wrrAp�--
---------------------------------------------------------------}Yi(---
i --+ -L-L--L--L--L--1--1--1--1--1--1--1--1--1--1--J--�--�--�--�---�---
5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 105 110 115 120
Time (hours)
— Inflow
Primary

CROSSING 2
DEP Cary Type 1124-hr 10-yr 24 hour Rainfall=5.01 "
Prepared by Appian Consulting Engineers, PA Page 5
HydroCADO 8.00 s/n 003961 © 2006 HydroCAD Software Solutions LLC 6/1/2023
Subcatchment 2: Into Culvert 2
Inflow Hydrograph
Runoff = 177.46 cfs @ 12.26 hrs, Volume= 18.068 af, Depth= 1.73"
Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-120.00 hrs, dt= 0.05 hrs
Type II 24-hr 10-yr 24 hour Rainfall=5.01"
Area (ac) CN Description
15.000
55
Woods, Good, HSG B
0.300
85
Gravel roads, HSG B
6.000
61
>75% Grass cover, Good, HSG B
3.000
98
Paved roads
2.500
1
Open Water- Ponds
26.000
65
Ex 2 acre lots, 12% imp, HSG B
67.000
70
FUT 1/2 acre lots, 25% imp, HSG B
5.200
75
FUT 1/4 acre lots, 38% imp, HSG B
125.000
66
Weighted Average
100.154
Pervious Area
24.846
Impervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
30.0 3,500 1.94 Direct Entry, Site Flow
1
w 1
3 1
0
LL
Subcatchment 2: Into Culvert 2
Hydrograph
II__II__II__II__II__I _I_
_- I I I I I I
-
----------------------------------------------------------------
--------------------- -- -- -- -- ---e rCI�41=hr '10= -IIIr-21II hour
-
------------- --- -- T-
-��-I---I---I------- -----hour-
__II_ II----_-�-I I I -T--T--rTTTTT-T--T--T---------- IRainfaN-5.0 "- r -- ---T--T-- Rwn6fif'IAr'eaT15.'I000Ta'c T
T- T-- T-- T--T--T--T--T-- T--T-- ;--R-UnoffVd-ume=9$10G$af-
T--T--T--T --T --T-- T--T-- -------uethll='LIIrZ3"-
--'r- T--T--T--T--T--T--T--T--T
I I I I I I I I-----fawi3;0' -
r T--T--r--T__T__T__T__T__T__1--1---------------I---I-__I--I-__I-_�_I_-
--r-r--r--r--r--r--r-_r--r--r--1--1--------------- --T-c�VISMa.aIF-ylrv-
--r -r--r--r--T--T--T--T--T--T--1--1---------------------I---
GI�-61� -
--r -r--r--r--T--T--T--r--r--r--1--1---I---I---I---I---I---I---r--r--r--r--
--r -r--r--r--r--r--r--r--r--r--r--r---I---I---I---I---I---I---I---I---I---r--
--r r--r--r--r--r--r--r--r--r--r--r---I---I---I---I---I---I---I---I---I---r--
5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 105 110 115 120
Time (hours)
— Runoff

CROSSING 2
DEP Cary Type 1124-hr 10-yr 24 hour Rainfall=5.01 "
Prepared by Appian Consulting Engineers, PA Page 6
HydroCADO 8.00 s/n 003961 © 2006 HydroCAD Software Solutions LLC 6/1/2023
Pond C2: Culvert 2
Inflow Area =
125.000 aq
Inflow Depth = 1.73"
for 10-yr 24 hour event
Inflow =
177.46 cfs@
12.26 hrs, Volume=
18.068 of
Outflow =
177.46 cfs @
12.26 hrs, Volume=
18.068 af, Atten= 0%, Lag= 0.0 min
Primary =
177.46 cfs @
12.26 hrs, Volume=
18.068 of
Routing by Stor-Ind method, Time Span= 5.00-120.00 hrs, dt= 0.05 hrs
Peak Elev= 299.54'@ 12.26 hrs
Device Routing
Invert
Outlet Devices
#1 Primary
295.40'
72.0" x 65.0' long Barrel 1 (Low Flow)
RCP, square edge headwall, Ke= 0.500
Outlet Invert= 295.00' S= 0.0062 T Cc= 0.900
n= 0.012 Concrete pipe, finished
#2 Primary
297.60'
72.0" x 65.0' long Barrel 2RCP, square edge headwall, Ke= 0.500
Outlet Invert= 296.95' S= 0.0100'/' Cc= 0.900
n= 0.012 Concrete pipe, finished
#3 Primary
297.60'
72.0" x 65.0' long Barrel 3RCP, square edge headwall, Ke= 0.500
Outlet Invert= 296.95' S= 0.0100'/' Cc= 0.900
n= 0.012 Concrete pipe, finished
Primary OutFlowMax=176.38 cfs@ 12.26 hrs HW=299.53' (Free Discharge)
1=Barrel 1 (Low Flow)(Barrel Controls 110.02 cfs @ 7.47 fps)
2=Barrel 2 (Barrel Controls 33.18 cfs @ 6.30 fps)
3=Barrel 3 (Barrel Controls 33.18 cfs @ 6.30 fps)
Pond C2: Culvert 2
Hydrograph
----I---------I---I---I---I---I---I---I---I---I---I---I---I---I---I---I---I---I---
-- I-h lowalrea=ll12 000aic-
--1,- -1,---1,---1,---1,---1,---1,---1,---1,---1,---1,------------------------------------
R"KEfev=2�9'I; 54' -
------I-- - --I ---
--1,- -1,---1,---1,---1,---1,---1,---1,---1,---1,---1,---1,---1,---1,---1,---1,---1,---1,---1,---1,---1,---1,---
--1,- -1,---1,---1,---1,---1,---1,---1,---1,---1,---1,---1,---1,---1,---1,---1,---1,---1,---1,---1,---1,---1,---
--I,--1,---
�--�
1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1
r --i--F--F--r- -r--i --i --i-----r--i --i --i --i--------I---i --i --I---
--r -_-----r--r--r--r--------------r--_--_--_--I_--I_--I_--I_--I_--I_--I_--
r- I I F--- F--- r- - -r- - -I --I I I- r - - -
I
I
I r I - - I - - r--r--r- -r- -I - - I - - I - - I - - -r - -I --I --I --I--I---I---I---I --I --I---
--r -_-----r--r--r--r--------------r--_--_--_--I_--I_--I_--I_--I_--I_--I_--
--r -I_--I_--r--r--r--r--I_--I_--I_--I_--r--I_--I_--I_--I_--I_--I_--I_--I_--I_--I_--
--r I---I---r--r--r --r --I---I---I---I---r --I---I---I---I---I---I---I---I---I---I---
--r I_--I_--r--r--r--r--I_--I_--I_--I_--r--I_--I_--I_--I_--I_--I_--I_--I_--I_--I_--
--r -I--I_--r--r--r--r--I_--I_--I_--I_--r--I_--I_--I_--I_--I_--I_--I_--I_--I_--I_--
5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 105 110 115 120
Time (hours)
— Inflow
Primary

CROSSING 2
DEP Cary Type // 24-hr 25-yr 24 hour Rainfall=5.93"
Prepared by Appian Consulting Engineers, PA Page 7
HydroCADO 8.00 s/n 003961 © 2006 HydroCAD Software Solutions LLC 6/1/2023
Subcatchment 2: Into Culvert 2
Inflow Hydrograph
Runoff = 250.94 cfs @ 12.26 hrs, Volume= 24.880 af, Depth= 2.39"
Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-120.00 hrs, dt= 0.05 hrs
Type II 24-hr 25-yr 24 hour Rainfall=5.93"
Area (ac) CN Description
15.000
55
Woods, Good, HSG B
0.300
85
Gravel roads, HSG B
6.000
61
>75% Grass cover, Good, HSG B
3.000
98
Paved roads
2.500
1
Open Water- Ponds
26.000
65
Ex 2 acre lots, 12% imp, HSG B
67.000
70
FUT 1/2 acre lots, 25% imp, HSG B
5.200
75
FUT 1/4 acre lots, 38% imp, HSG B
125.000
66
Weighted Average
100.154
Pervious Area
24.846
Impervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
30.0 3,500 1.94 Direct Entry, Site Flow
Subcatchment 2: Into Culvert 2
Hydrograph
280 -- -- -- -- -- -- -- -- -- -- -- -- ---------------------------------
260 250.94cfs r-4--+--+--+--7--7--7-- --------------------------------li --
240 --,, -,, --,, --,, --,, --,, --,, -- -- -- -- '-- TYPE IVZ4,-h1" 2v=y��,r-24 hour-
220 --1 -�I -- -- -- -- -- -- -- -- -----------------IRain-fall=3.33"
200 --' -' --' --' --' --' --' ---' --
------------------------
---
'AteaT125.'000 a'c Runoff
Runoff Volume=24MO of
w160 -- - -- -- -- -- -- -- -- -- -- -- ---------------------------------
_kun9ff O-ellthl=2'�39"-
140 --+-r--r--r--+--+--+--+--+--+--+--+--+--+- -
a 120 ---r--r--r--r--r--r-- -- -- -- ----------�[Qw-gth 000�--
100 --,--+--+-----+--+--+-- -- -- -- -------------------1r,=�3O:tYnlcin -
80 --,-------------------- -- -- -- -------------------------—GN=p6-
60 --il
-----------------------------------------------------------------
40 -- L--L--L--1--1--1--1--1--1-- -- ---'---------------------------'---
20 -- -- -- -- -- -- -- -- -- -- -- ---------------------------------
0
5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 105 110 115 120
Time (hours)
— Runoff

CROSSING 2
DEP Cary Type // 24-hr 25-yr 24 hour Rainfall=5.93"
Prepared by Appian Consulting Engineers, PA Page 8
HydroCADO 8.00 s/n 003961 © 2006 HydroCAD Software Solutions LLC 6/1/2023
Pond C2: Culvert 2
Inflow Area =
125.000 aq
Inflow Depth = 2.39"
for 25-yr 24 hour event
Inflow =
250.94 cfs@
12.26 hrs, Volume=
24.880 of
Outflow =
250.94 cfs @
12.26 hrs, Volume=
24.880 af, Atten= 0%, Lag= 0.0 min
Primary =
250.94 cfs @
12.26 hrs, Volume=
24.880 of
Routing by Stor-Ind method, Time Span= 5.00-120.00 hrs, dt= 0.05 hrs
Peak Elev= 300.20'@ 12.26 hrs
Device Routing
Invert
Outlet Devices
#1 Primary
295.40'
72.0" x 65.0' long Barrel 1 (Low Flow)
RCP, square edge headwall, Ke= 0.500
Outlet Invert= 295.00' S= 0.0062 T Cc= 0.900
n= 0.012 Concrete pipe, finished
#2 Primary
297.60'
72.0" x 65.0' long Barrel 2RCP, square edge headwall, Ke= 0.500
Outlet Invert= 296.95' S= 0.0100 T Cc= 0.900
n= 0.012 Concrete pipe, finished
#3 Primary
297.60'
72.0" x 65.0' long Barrel 3RCP, square edge headwall, Ke= 0.500
Outlet Invert= 296.95' S= 0.0100 T Cc= 0.900
n= 0.012 Concrete pipe, finished
Primary OutFlowMax=249.98 cfs@ 12.26 hrs HW=300.19' (Free Discharge)
1=Barrel 1 (Low Flow)(Barrel Controls 140.09 cfs @ 7.92 fps)
2=Barrel 2 (Barrel Controls 54.95 cfs @ 6.92 fps)
3=Barrel 3 (Barrel Controls 54.95 cfs @ 6.92 fps)
Pond C2: Culvert 2
Hydrograph
280 ---------- --
260 -- ---------------- --------------------------------
250.94 cfs
220 -- - -- -- -- -- -- -- -- -- ----- -- -- --------------------------
200 -- - -- -- -- --ill---ill---ill---ill---ill---ill---ill---ill---ill-- ----- EIev ----- 2Q' -
180 --------- -- -- -- -----------------
------------------------------
m160 --------- -- -- ---------------- --------------------------------
3 140 --r -r--r--r--r--r--r--r--r--r--r--r--r--r--r--r--r--r-----r--r--r--
0
u120 --r - -- -- ----r--r-- -- -------r-- -- -- ------------- -- -----
100 --, -, --, --, --, --, --, --, --,--- - - - - -, --, --, --,--------- - - - - -, --, - -, ---
80 --li -li --'i--------'i --'i --'i --'i --'i-----'i --'i --'i --'i --'i-----------'i --'i--'i---
60 --L -------L--L--L--L--------------L--------------------------------
40 -----'--- -- -- -------------'--- --'---------------------------'---
0
5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 105 110 115 120
Time (hours)
— Inflow
Primary

CROSSING 2
DEP Cary Type 1124-hr 50-yr 24 hour Rainfall=6.67"
Prepared by Appian Consulting Engineers, PA Page 9
HydroCADO 8.00 s/n 003961 © 2006 HydroCAD Software Solutions LLC 6/1/2023
Subcatchment 2: Into Culvert 2
Inflow Hydrograph
Runoff = 313.44 cfs @ 12.25 hrs, Volume= 30.702 af, Depth= 2.95"
Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-120.00 hrs, dt= 0.05 hrs
Type II 24-hr 50-yr 24 hour Rainfall=6.67"
Area (ac) CN Description
15.000
55
Woods, Good, HSG B
0.300
85
Gravel roads, HSG B
6.000
61
>75% Grass cover, Good, HSG B
3.000
98
Paved roads
2.500
1
Open Water- Ponds
26.000
65
Ex 2 acre lots, 12% imp, HSG B
67.000
70
FUT 1/2 acre lots, 25% imp, HSG B
5.200
75
FUT 1/4 acre lots, 38% imp, HSG B
125.000
66
Weighted Average
100.154
Pervious Area
24.846
Impervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
30.0 3,500 1.94 Direct Entry, Site Flow
Subcatchment 2: Into Culvert 2
Hydrograph
320 313.44 cfs —Runoff
300 --',--------------- --- -- -- -- -- -----e rC,�4,=hr 5= -,r 2, M-or-
280 --I--r--r--r--t--t--t--7--7--7-----r---1 ~-------------- ��-----c--c-----
260 --'-L--L--L--1--1--1--1--1--1-- -----------------Ralinfalk=6.67"_
240 --1-1--1--1--1--1--1-- 1-- -- -- -----Rgnbff Atea#125.000 ac
220 ---r--r--r--T--T--T------r--,--;--Runoff Volume= 0!702 af-
H200 ---r--r--r-- -- -- -- -- -- -- ------------------------------�---
180 --'-----------------'--- -- ---------'---
3 I I I I I I I I I I I I I I
i° 160 - -,-------------------- -- -- -- -------- -- - --- --- -- --
raw ength= 0
140 --Ir -r--r--r--+--+--+--rt--rt--rt--y--y---li---li---------I---I----I---I---i---I-
120 ---L--L--L--1--1--1--1--1--1-- -----'------------ '--TCT30,0_Imirl_
100 --'l -'- - -'- --' --' --' --' ---' ---' ---'---'---------------------------C-N_6'6 -
80 r r--r--r--r--r--r--r--r--r--r--r---i---i---i---i---i---i---i---i---i---r--
60 -- r--r--r-- -- -- -- -- -- -- -- ---'---------------------------'---
40 --'-'--'--'--'--'--'--'--'--'--'--'------------------------------'i --
0
5 10 15 20 25 30 35 40 45 50 55 60 65 70 A 80 85 90 95 100 105 110 115 120
Time (hours)

CROSSING 2
DEP Cary Type 1124-hr 50-yr 24 hour Rainfall=6.67"
Prepared by Appian Consulting Engineers, PA Page 10
HydroCADO 8.00 s/n 003961 © 2006 HydroCAD Software Solutions LLC 6/1/2023
Pond C2: Culvert 2
Inflow Area =
125.000 aq
Inflow Depth = 2.95"
for 50-yr 24 hour event
Inflow =
313.44 cfs@
12.25 hrs, Volume=
30.702 of
Outflow =
313.44 cfs @
12.25 hrs, Volume=
30.702 af, Atten= 0%, Lag= 0.0 min
Primary =
313.44 cfs @
12.25 hrs, Volume=
30.702 of
Routing by Stor-Ind method, Time Span= 5.00-120.00 hrs, dt= 0.05 hrs
Peak Elev= 300.71'@ 12.25 hrs
Device Routing
Invert
Outlet Devices
#1 Primary
295.40'
72.0" x 65.0' long Barrel 1 (Low Flow)
RCP, square edge headwall, Ke= 0.500
Outlet Invert= 295.00' S= 0.0062 T Cc= 0.900
n= 0.012 Concrete pipe, finished
#2 Primary
297.60'
72.0" x 65.0' long Barrel 2RCP, square edge headwall, Ke= 0.500
Outlet Invert= 296.95' S= 0.0100'/' Cc= 0.900
n= 0.012 Concrete pipe, finished
#3 Primary
297.60'
72.0" x 65.0' long Barrel 3RCP, square edge headwall, Ke= 0.500
Outlet Invert= 296.95' S= 0.0100'/' Cc= 0.900
n= 0.012 Concrete pipe, finished
Primary OutFlowMax=312.76 cfs@ 12.25 hrs HW=300.70' (Free Discharge)
1=Barrel 1 (Low Flow)(Barrel Controls 164.11 cfs @ 8.25 fps)
2=Barrel 2 (Barrel Controls 74.32 cfs @ 7.34 fps)
3=Barrel 3 (Barrel Controls 74.32 cfs @ 7.34 fps)
Pond C2: Culvert 2
Hydrograph
340 - - I - - - --I - -- -- -- -- --- -- - --I - --I - -- --------I---I---I---I---I---I---I---I---
313.44 cfs —Inflow
320 -- -- -- -------------I--------------------------------I--- _Primary
300 --I, -I, _-II --II --II I I I I I I I I I
-- -- ---III -nfrow Area=ll125.000 aic -
280 --r -r--r--r--r--r--r--r--r--------r--r--r-----------------------I---
260 --p"�Ejev
----I--- -- -- -------------I----------II�FJ -a 71V -
240--Ili -I - -
I --I --I --I --I --I --I --I -----I --I --I --I --I-----------I --I--II---
220 --IF- -I - -I -- IF- -- IF- -- IF- - -Ir- -I - -Ii --I - - - - -Ir --I --I --I --I--------I---I --I --I---
w-I---I---�--�--�--�--I---I---I---I---�--I---I---I---I---I---I---I---I---I---I---
�- 180 --L -I---I---L--L--L--L--I---I---I---I---L--I---I---I---I---I---I---I---I---I---I---
3 I I I I I I I I I I I I I I I I I I I I I I
° 160 - - I, -- - - - - -
I, --I, --I, --I,--------------I, --,---------------------------II---
LL
140 --r -r--r--r--r--r--r--r--r--------r--r--r-----------------------I---
120 --------- L--L--L--L-----
------I--- -----------------------------I---
100 --I- -------------------------------------------------------------I---
I
-- -- -- -- -- -- -- --
60 --r -------r--r--r--r--------------r-----------------------------I---
40 --Ii ---Ii --Ii --Ii --Ii --Ii --Ii --Ii --Ii-----Ii --Ii --Ii --Ii --Ii-----------Ii --II--II---
20
5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 105 110 115 120
Time (hours)

CROSSING 2
DEP Cary Type 1124-hr 100-yr 24 hour Rainfall=7.41 "
Prepared by Appian Consulting Engineers, PA Page 11
HydroCADO 8.00 s/n 003961 © 2006 HydroCAD Software Solutions LLC 6/1/2023
Subcatchment 2: Into Culvert 2
Inflow Hydrograph
Runoff = 378.22 cfs @ 12.25 hrs, Volume= 36.767 af, Depth= 3.53"
Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-120.00 hrs, dt= 0.05 hrs
Type II 24-hr 100-yr 24 hour Rainfall=7.41"
Area (ac) CN Description
15.000
55
Woods, Good, HSG B
0.300
85
Gravel roads, HSG B
6.000
61
>75% Grass cover, Good, HSG B
3.000
98
Paved roads
2.500
1
Open Water- Ponds
26.000
65
Ex 2 acre lots, 12% imp, HSG B
67.000
70
FUT 1/2 acre lots, 25% imp, HSG B
5.200
75
FUT 1/4 acre lots, 38% imp, HSG B
125.000
66
Weighted Average
100.154
Pervious Area
24.846
Impervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
30.0 3,500 1.94 Direct Entry, Site Flow
Subcatchment 2: Into Culvert 2
Hydrograph
420
400
-- -- --
378.22ds
--
I+--+--+--+--+--+--+--+--I--I---------------------------------
--
--
--
-- --
-- -- -- -------------------------------
--
380
360
--r
- -Ir
-r--r--r--r--r--r--r--r--r--r--r-----------------i---r--r--r--r--
-r-
-r-
- r-
- r-
- r-
- r----------------
Typip 11-IL4i�rjQ(Y `�• �4-6�r-
340
320
--II
--II-
-T--
----------------'I---
r-
- T-
- T-
- T-
-T ---T
--
-T
7--1--1---I---I---I---I---I---I---II--/�-I---I---I
-- -- -- ---------------II-
--
Ftainfa U=7i41�.
300
--II
--
--
--
--
--
-- --
I I
I -Runoff Area=1I2-,000ac
280
260
--I
--L
- - -
-L--L--L--1--1--1--1--1--1--
- - -
-
-----IRunof
-
VolurneT36.767 a
w 240
w
- -
- --
--
--
--
--
-- --
-- -- -- ------------I--
I---I---I---I---I---I---
RUnoff_D_ept11=_3.5T_ _
LL200
--'
-r--r--r--
--
--
-- --
-- -- -----------''fibv-to#i�r,'5IIOF-
180
--Ir
-r--r--r--r--r--r--rt--rt--rt--
r--r--r--r--r--7--7--7--
--------------------IT-
--------------------
TCr30.0 milrt-
140
--I,
- --
--
--
--
--
-- --
-------
----------------------- - - - - -- --
120
--II-
-------------------
--
---------------------------r
_ICN=G6 _
100
--II-
-------------------?--?--?----------------------------------II---
80
--I---!--!---I---I---I---I---I---I---I---I---I---I---
60
--I
L--L--L--1--1--1--1--1--1--
-- ------------------------------I---
40
--
L--L--L--1--1--1--1--1--1--
-- ---I---------------------------I---
20
--
- --+--
--+--+--+--+--+--+--I--I------------------------------I---
0
5 10
15
20
25
30
35
40 45
50
55 60 65
70 75 80 85 90 95 100 105 110 115 120
Time (hours)
— Runoff

CROSSING 2
DEP Cary Type 1124-hr 100-yr 24 hour Rainfall=7.41 "
Prepared by Appian Consulting Engineers, PA Page 12
HydroCADO 8.00 s/n 003961 © 2006 HydroCAD Software Solutions LLC 6/1/2023
Pond C2: Culvert 2
Inflow Area =
125.000 aq
Inflow Depth = 3.53"
for 100-yr 24 hour event
Inflow =
378.22 cfs@
12.25 hrs, Volume=
36.767 of
Outflow =
378.22 cfs @
12.25 hrs, Volume=
36.767 af, Atten= 0%, Lag= 0.0 min
Primary =
378.22 cfs @
12.25 hrs, Volume=
36.767 of
Routing by Stor-Ind method, Time Span= 5.00-120.00 hrs, dt= 0.05 hrs
Peak Elev= 301.20'@ 12.25 hrs
Device Routing
Invert
Outlet Devices
#1 Primary
295.40'
72.0" x 65.0' long Barrel 1 (Low Flow)
RCP, square edge headwall, Ke= 0.500
Outlet Invert= 295.00' S= 0.0062 T Cc= 0.900
n= 0.012 Concrete pipe, finished
#2 Primary
297.60'
72.0" x 65.0' long Barrel 2RCP, square edge headwall, Ke= 0.500
Outlet Invert= 296.95' S= 0.0100'/' Cc= 0.900
n= 0.012 Concrete pipe, finished
#3 Primary
297.60'
72.0" x 65.0' long Barrel 3RCP, square edge headwall, Ke= 0.500
Outlet Invert= 296.95' S= 0.0100'/' Cc= 0.900
n= 0.012 Concrete pipe, finished
Primary OutFlowMax=377.94 cfs@ 12.25 hrs HW=301.20' (Free Discharge)
1=Barrel 1 (Low Flow)(Barrel Controls 187.77 cfs @ 8.56 fps)
2=Barrel 2 (Barrel Controls 95.09 cfs @ 7.72 fps)
3=Barrel 3 (Barrel Controls 95.09 cfs @ 7.72 fps)
Pond C2: Culvert 2
Hydrograph
420
400
----------
378.22cfs--
--
- --
--
- - -
--
-- -
--------------
---------------
--------------------------------
--------------------------------
380
--r ------
-r-
-r-
-r-
-r------------
--r----FF----------------------/}------
360
-- - -- --
--
--
--
-- --
------- I1-4101 W AreaQ 125/}a6
340
-- - -- --
--
--
--
-- --
-- -----
320
--,--,---,---,---,---,---,---,---,---,--------------f?ef�'ffev=3�'F';
20' -
300
--'--'---'---'---'---------------------------'---
------------- -- -----
280
--'- -'---'---'---'---'---'---'---'---'---'---'---'---------------------------'---
260
------'---
--
--
--
-----------'---
--'---------------------------'---
w240
---------
--
--
--
-----------------------------------------------
220
---------
--
--
--
--------------
--------------------------------
0 200
--r -------r--r--r--r--------------r--------------------------------
160
-- - -- --
--
--
--
-- --
-- ----- -- -- -- ------------- -- - -r --
120
--,- -,---,---,---,---,---,---,---,---,---,---,---,---------------------------,---
100
--'- -'---'---'---'---'---'---'---'---'---'---'---'---------------------------'---
80
- -L -'------IL
IL
IL
L----
-------'--- --'---------------------------'---
60
- -LI - - -'---
--
--
--
-----------'---
--'---------------------------'---
40
--11 ------
--
--
--
--------------
--------------------------------
0
5 10 15 20
25
30
35
40 45
50 55 60 65 70 75 80 85 90 95 100 105 110 115 120
Time (hours)
— Inflow
Primary

CROSSING 2
DEP Cary Type // 24-hr 500-yr 24 hour Rainfall=9.22"
Prepared by Appian Consulting Engineers, PA Page 13
HydroCADO 8.00 s/n 003961 © 2006 HydroCAD Software Solutions LLC 6/1/2023
Subcatchment 2: Into Culvert 2
Inflow Hydrograph
Runoff = 543.36 cfs @ 12.25 hrs, Volume= 52.368 af, Depth= 5.03"
Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-120.00 hrs, dt= 0.05 hrs
Type II 24-hr 500-yr 24 hour Rainfall=9.22"
Area (ac) CN Description
15.000
55
Woods, Good, HSG B
0.300
85
Gravel roads, HSG B
6.000
61
>75% Grass cover, Good, HSG B
3.000
98
Paved roads
2.500
1
Open Water- Ponds
26.000
65
Ex 2 acre lots, 12% imp, HSG B
67.000
70
FUT 1/2 acre lots, 25% imp, HSG B
5.200
75
FUT 1/4 acre lots, 38% imp, HSG B
125.000
66
Weighted Average
100.154
Pervious Area
24.846
Impervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
30.0 3,500 1.94 Direct Entry, Site Flow
Subcatchment 2: Into Culvert 2
Hydrograph
600 -- -- -- -- -- -- -- -- --
-- -- -- ---------------------------------
543.36 cfs
550 --; -; --, --, --, --, --, -- -- -- -- -----------------------------,---;
500 --'r-t--t--r-- -- ----rt--rt--rt--y--y-T�/-pq-ll_'24,-hr', 5QO-yu' 4�]o C_
450 --'L-L--L--L-- -- ----i--i--i-- -- ----------------Rain ,fial1=9.2..
400 - - - - - - - - - Runoff Area=1,25.000 ac
�RUnoff Volurrie=�52.368 cif
350 --- -r--r--r--r--r--r--7--7--7---------------------------r--r--r--r--
RU ndff De th=5.03"
3 300 -- - -- -- -- -- -- -- -- -- -- -- ---------------------------------
LL F16W L6nothr3,',5OO'
250 --' -' --' --' --' --' --' ---' -- -----------
TcT30ffmih
200 - r--r--r--T--T--T-- -- --------------------------------ICK=66
150 -- - -- -- -- -- -- -- -- -- -- -- ---------------------------------
100 --I- I--I----I--I--I----'---'---'---'---'---'---------------------------'---
50 r r r r r--------------
---------------i---i
0
5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 105 110 115 120
Time (hours)

CROSSING 2
DEP Cary Type // 24-hr 500-yr 24 hour Rainfall=9.22"
Prepared by Appian Consulting Engineers, PA Page 14
HydroCADO 8.00 s/n 003961 © 2006 HydroCAD Software Solutions LLC 6/1/2023
Pond C2: Culvert 2
Inflow Area =
125.000 aq
Inflow Depth = 5.03"
for 500-yr 24 hour event
Inflow =
543.36 cfs@
12.25 hrs, Volume=
52.368 of
Outflow =
543.36 cfs @
12.25 hrs, Volume=
52.368 af, Atten= 0%, Lag= 0.0 min
Primary =
543.36 cfs @
12.25 hrs, Volume=
52.368 of
Routing by Stor-Ind method, Time Span= 5.00-120.00 hrs, dt= 0.05 hrs
Peak Elev= 302.39'@ 12.25 hrs
Device Routing
Invert
Outlet Devices
#1 Primary
295.40'
72.0" x 65.0' long Barrel 1 (Low Flow)
RCP, square edge headwall, Ke= 0.500
Outlet Invert= 295.00' S= 0.0062 T Cc= 0.900
n= 0.012 Concrete pipe, finished
#2 Primary
297.60'
72.0" x 65.0' long Barrel 2RCP, square edge headwall, Ke= 0.500
Outlet Invert= 296.95' S= 0.0100 T Cc= 0.900
n= 0.012 Concrete pipe, finished
#3 Primary
297.60'
72.0" x 65.0' long Barrel 3RCP, square edge headwall, Ke= 0.500
Outlet Invert= 296.95' S= 0.0100 T Cc= 0.900
n= 0.012 Concrete pipe, finished
Primary OutFlowMax=542.35 cfs@ 12.25 hrs HW=302.39' (Free Discharge)
1=Barrel 1 (Low Flow)(Barrel Controls 241.63 cfs @ 9.23 fps)
2=Barrel 2 (Barrel Controls 150.36 cfs @ 8.52 fps)
3=Barrel 3 (Barrel Controls 150.36 cfs @ 8.52 fps)
Pond C2: Culvert 2
Hydrograph
VUU
543.36 cfs — Inflow
550 - -i -i --li --li --li --li --li --li --li --i-----li --li --li --li --i------- - - - -li - -li --i- —Primary
500 --r-------r--r--r--r-----------
---raflt�wrep=12.Q/y�AQa -
450 ------'--- -- -- -------------'----------1'� ��- "k E1ev�Ft2q'iiy- -
400 --'l -' --' --' --' --' --' --' --' --'--'---' --' --' --' --'--------'---' --' --'---
w350 -- - -- -- -- -- -- -- -- -- ----- -- -- -- ------------- -- -----
3 300 ------i--- -- -- -------------i--- -----------------------------i---
0
LL
250 --' -' --' --' --' --' --' --' --' --'--'---' --' --' --' --'--------'---' --' --'---
200 --r - -- -- ----r--r-- -- -------r-- -- -- ------------- -- -----
150 --------- -- -- ---------------- --------------------------------
100 --L
50 --li --li --li --li --li --li --i-----li --li --li --li --i-----------li --i--li---
5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 105 110 115 120
Time (hours)

CROSSING 2
DEP Cary Type 1124-hr 1000-yr 24 hour Rainfall=10.00"
Prepared by Appian Consulting Engineers, PA Page 15
HydroCADO 8.00 s/n 003961 © 2006 HydroCAD Software Solutions LLC 6/1/2023
Subcatchment 2: Into Culvert 2
Inflow Hydrograph
Runoff = 616.55 cfs @ 12.24 hrs, Volume= 59.349 af, Depth= 5.70"
Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-120.00 hrs, dt= 0.05 hrs
Type II 24-hr 1000-yr 24 hour Rainfall=10.00"
Area (ac) CN Description
15.000
55
Woods, Good, HSG B
0.300
85
Gravel roads, HSG B
6.000
61
>75% Grass cover, Good, HSG B
3.000
98
Paved roads
2.500
1
Open Water- Ponds
26.000
65
Ex 2 acre lots, 12% imp, HSG B
67.000
70
FUT 1/2 acre lots, 25% imp, HSG B
5.200
75
FUT 1/4 acre lots, 38% imp, HSG B
125.000
66
Weighted Average
100.154
Pervious Area
24.846
Impervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
30.0 3,500 1.94 Direct Entry, Site Flow
Subcatchment 2: Into Culvert 2
Hydrograph
650 616.55cfs `----+--+--+-- -- -- -- -- ---------------------------------
600 ---r--r--r--+--+--+-- -- -- -- -- Type; II �4-hr-1090jyr �4 h10-LI r
550 ---r--r--r--+--+--+-- -- -- -- -- --- R inf -- --- Od::
500 --;-;--;--;--;--;--;--;--;--;--;--;------' u;no f 4rep=i,25�000 c1C -
450 - -; -;--;--;--;--;--;--;--;--;--;--;---I R'unQff'V-61- �e=59.349 �f
400 --F -T- T- r--r--r--r ---F -F -F -1 ;------------------------------ -
w Runpff,Delpt4=�.7d..
3 350 o --,-------------------- -- -- -- -----,---,---,- Flow Lenc�'th=3,';5
LL 300--,0�.
--------------------?--?--?-- ----------------------------0--- --
Tc=30.'11 min
250 --'---------------------' ---' ---' ---'---'---'---'------------------'--I---'---
iCN=6'6
200 --'---------------------' ---' ---' ---'---'---'---------------------------'---
50 - - + + - - + - - + - - + - - + - - + - - 4 - - 4 - - 4 - -
0
5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 105 110 115 120
Time (hours)
— Runoff

CROSSING 2
DEP Cary Type 1124-hr 1000-yr 24 hour Rainfall=10.00"
Prepared by Appian Consulting Engineers, PA Page 16
HydroCADO 8.00 s/n 003961 © 2006 HydroCAD Software Solutions LLC 6/1/2023
Pond C2: Culvert 2
Inflow Area =
125.000 aq
Inflow Depth = 5.70"
for 1000-yr 24 hour event
Inflow =
616.55 cfs@
12.24 hrs, Volume=
59.349 of
Outflow =
616.55 cfs @
12.24 hrs, Volume=
59.349 af, Atten= 0%, Lag= 0.0 min
Primary =
616.55 cfs @
12.24 hrs, Volume=
59.349 of
Routing by Stor-Ind method, Time Span= 5.00-120.00 hrs, dt= 0.05 hrs
Peak Elev= 302.93'@ 12.24 hrs
Device Routing
Invert
Outlet Devices
#1 Primary
295.40'
72.0" x 65.0' long Barrel 1 (Low Flow)
RCP, square edge headwall, Ke= 0.500
Outlet Invert= 295.00' S= 0.0062 T Cc= 0.900
n= 0.012 Concrete pipe, finished
#2 Primary
297.60'
72.0" x 65.0' long Barrel 2RCP, square edge headwall, Ke= 0.500
Outlet Invert= 296.95' S= 0.0100'/' Cc= 0.900
n= 0.012 Concrete pipe, finished
#3 Primary
297.60'
72.0" x 65.0' long Barrel 3RCP, square edge headwall, Ke= 0.500
Outlet Invert= 296.95' S= 0.0100'/' Cc= 0.900
n= 0.012 Concrete pipe, finished
Primary OutFlowMax=614.98 cfs@ 12.24 hrs HW=302.92' (Free Discharge)
1=Barrel 1 (Low Flow)(Barrel Controls 261.71 cfs @ 9.49 fps)
2=Barrel 2 (Barrel Controls 176.63 cfs @ 8.84 fps)
3=Barrel 3 (Barrel Controls 176.63 cfs @ 8.84 fps)
Pond C2: Culvert 2
Hydrograph
650
--
--
--
--
--------------
--------------------------------
616.55cfs
--r
600
-------r--r--r--r------------
r--------------------------------
-- Inflow Area=125.000 aic
550
--r
-r--r--r--r--r--r--r--r--------r--r--r--------------------------
07%q'
500
--r
-------r--r--r--r--------------r--���-----Pe44-k',EIev=302
-
450
--
- -- -
-r -
- r--
--
-- --
----I---r-- -- -- ------------- -- -----
w 400
--,
--- -,- --,
--,
--,
--,
-----------,---,
--,---------------------------,---
'. 350
- -
0 300
--'-
-'---'---'---'---'---'---'---'---'---'---'---'---------------------------'---
250
--'-
-'---'---'---'---'---'---'---'---'---'---'---'---------------------------'---
200
--L
-- - -'---
--
--
--
-----------'---
--'---------------------------'---
150
--
-------
--
--
--
-----------
------------------------------------
100
--
-------
--
--
--
--------------
--------------------------------
0
5 10 15 20
25
30
35
40 45
50 55 60 65 70 75 80 85 90 95 100 105 110 115 120
Time (hours)
— Inflow
Primary

CREEK CROSSING #3
CALCULATIONS

CULVERT CALCULATIONS
Project: DEP Cary Triangle Expressway
Description: CREEK CROSSING #3
IONSULT— ENGINEERS, PA
Designer: dcr
Date: 5/15/2023
W
1.1 Based on NCDOT topo, the contributing watershed for this culvert is approximately 10 acres (see attached Runoff
Map).
3T•
- IT
1.2 The watershed characteristics can be approximated as follows:
Total;
ACRES
CN
DESCRIPTION
1.0
55
Woods, Good, HSG B
3.0
85
Gravel Roads, HSG B
3.0
61
>75% Grass cover good HSG B
3.0
98
Paved Roads
10.0
79
Weighted CN
1.3 Using the SCS Method and rainfall information from NOAA at this location, the peak runoff rates are as follows:
STORM (24 hr)
FLOW (cfs)
1-yr
13.69
2-yr
19.47
10-yr
36.06
25-yr
46.25
50-yr
54.54
100-yr
62.89
500-yr
83.38
1000-yr
92.22
(see attached hydrographs)

CREEK CROSSING #3
2. DETERMINE CULVERT SIZ
Based on NCDOT contours and the topographical survey received, there is no known upstream culvert discharging into
the existing channel at this location. Since this culvert carries runoff from NCDOT transportation corridors, this culvert
will be designed to safely pass the 100 year storm without impoundment of water, and the 1,000 year storm does not
exceed the top of headwall (see attached hydrograpi A single 54" RCP is proposed at this location.
3.1 Per US COE 157, Regional Conditions for Culvert:
9. Culvert Placement. For all NWPs that allow for culvert placement, the following
conditions shall be applied:
a. For all i that involve the constructionlinstallation of culverts, measures shall be included in the
construction/installation that will promote the safe passage of fish and other aquatic organisms
33
Placement of culverts and other structures in streams shall be below the elevation of the streambed by one foot for
all culverts with a diameter greater than 48 inches, and 20% of the culvert diameter for culverts having a diameter
less than or equal to 48 inches. If the culvert outlet is submerged within a pool or scour hole and designed to provide
for aquatic passage, then culvert burial into the streambed is not required.
Culvert burial is not required for structures less than 72 inch diameterlwidth, where the slope of the culvert will be
greater than 2.5%, provided that all alternative options for flattening the slope have been investigated and aquatic
life movement/connectivity has been provided when possible (e.g., rock ladders, cross vanes, sills, baffles etc.).
Culvert burial is not required when bedrock is present in culvert locations.
Installation of culverts in wetlands shall, ensure continuity of water movement and be designed to adequately
accommodate high water or flood conditions. When roadways, causeways, or other f II projects are constructed
across FEMA-designated flcodways or wetlands, openings such as culverts or bridges shall be provided to maintain
the natural hydrology of the system as well as prevent constriction of the floodway that may result in destabilization
of streams or wetlands.
eim�w
a,i�r".11
- - - tom I
—f
A waiver from the depth specifications in this condition may be requested, in writing, by the permittee and issued by
the Corp. This waiver request must be specific as to the reasons(s) for the request. The waiver will be issued if it
can be demonstrated that the proposed design would result in less impacts to the aquatic environment. Culverts
placed across wetland fills purely for the purposes of equalizing surface water do not have to be buried, but the
culverts must be of adequate size and/or number to ensure unrestricted transmission of water.
b. Bank -full flows (or less) shall be accommodated through maintenance of the existing bank -full channel cross
sectional area. Additional culverts or culvert barrels at such crossings shall be allowed only to receive bank -full
flows.
Approach RR
Roahrrag
cw �rtbtuied
Bmk&n belowstreambed
- - - - - m appropriate
depth (ifrequire d).
Baffle/ Stream
Blockage Bottoxa
c. Culverts shall be designed and installed in such a manner that the original stream profiles are not altered and
allow for aquatic life movement during low flows. The dimension, pattern, and profile of the stream above and below
a pipe or culvert shall not be modified by widening the stream channel or by reducing the depth of the stream In
connection with the construction activity. The width, height, and gradient of a proposed culvert shall be such as to
pass the average historical low flow and spring flow without adversely altering flow velocity. If the width of the culvert
is wider than the stream channel, the culvert shall include multiple boxes/pipes, baffles, benches and/or sills to
maintain the natural width of the stream channel. If multiple culverts/pipeslbarrels are used, low flows shall be
accommodated in one culvertlpipe and additional culverts/pipes shall be installed such that they receive only flows
above bankfull.

CREEK CROSSING #3
3.2 Determine Low Flow/ Bankfull elevation: n/a
The single culvert will be buried 12" to comply with COE NWP 57 Regional Conditions.
As such, the vertical layout of the culvert looks like this:
CT•]C•]0CTy0I01�113:161
BARREL #1
ex bottom of stream= S 300.0
PRO INV RCP IN = 299.0
CULVERT #3 PIPE DIA PIPE SLOPE
Barrel 54 3.0%
Ex Ditch -
Pro Drive Elev.
12"
INV IN
299.0
300.0
310.0
M.,
TOP @ IN INV OUT TOP @ OUT
303.5 297.0 301.5
- 298.0 -
310.0
S. CULVERT I'• •
Using the SCS Method as described above for the proposed culverts, the following peak runoff elevations can be
determined:
STORM (24 hr)
Barrel
Flow (cfs)
Max Elevation
Discharge
Velocity (fps)
1-yr
13.69
300.97
3.19
2-yr
19.47
301.23
3.60
10-yr
36.06
301.87
4.44
25-yr
46.25
302.22
4.84
50-yr
54.54
302.49
5.12
100-yr
62.89
302.75
5.39
500-yr
83.38
303.35
5.95
1000-yr
92.22
303.59
6.16
(see attached hydrographs)

CREEK CROSSING 3
DEP Cary C3 Type 1124-hr 1-yr24 hour Rainfall=2.86"
Prepared by Appian Consulting Engineers, PA Page 1
HydroCADO 8.00 s/n 003961 © 2006 HydroCAD Software Solutions LLC 6/7/2023
Subcatchment 3: Into Culvert 3
Inflow Hydrograph
Runoff = 13.69 cfs @ 12.08 hrs, Volume= 0.906 af, Depth= 1.09"
Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-120.00 hrs, dt= 0.05 hrs
Type II 24-hr 1-yr 24 hour Rainfall=2.86"
Area (ac) CN Description
1.000 55 Woods, Good, HSG B
3.000 85 Gravel
3.000 61 >75% Grass cover, Good, HSG B
3.000 98 Paved roads
10.000
79 Weighted Average
7.000
Pervious Area
3.000
Impervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
15.0 1,200 1.33 Direct Entry, Site Flow
Subcatchment 3: Into Culvert 3
Hydrograph
i -
-, --, --, --, --------1------------------I---, --, --, --, -- -- --------I---
13.69 cfs
-1--1--1--J--J---1---1---1---1---1---L--L--L--1--1--L--�--�---1---I---
r-r--t--t--rt-- -- ---' - -- Type-WZ4-hlr1 yr-Mhour _
-- -
Rainfa11-2J86"
--! --!----- , - -, - --
R4anQifTAe=1�0-a0--
-- --- 1 -- 1 -- 1---1---1---1---1---1--- Atjroff Votunw=0:11946-a# -
- i - i -- -- ----------- ------ i-Runo#-Deptthr1109---
1 1 1 1 1 1
--------------------------=------------------------
--L-L--1--1--1--J--J--- -- Flow Length=1-,-20W _
L - L L - _ 1 1 _ ter]
1 --Y-Y__t__t__Y--Y--Y------------------Y--Y--Y--t--t- TC-Y1 5-0 min- -
_ I - -
--- - -- - - - - - - - - - - - ----I-- -- - --- - - -- - -- - -- - -- - -- ---- - -I- --
5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 105 110 115 120
Time (hours)
— Runoff

CREEK CROSSING 3
DEP Cary C3 Type 1124-hr 1-yr24 hour Rainfall=2.86"
Prepared by Appian Consulting Engineers, PA Page 2
HydroCADO 8.00 s/n 003961 © 2006 HydroCAD Software Solutions LLC 6/7/2023
Pond C3: Culvert 3
Inflow Area =
10.000 ac,
Inflow Depth = 1.09"
for 1-yr 24 hour event
Inflow =
13.69 cfs @
12.08 hrs, Volume=
0.906 of
Outflow =
13.69 cfs @
12.08 hrs, Volume=
0.906 af, Atten= 0%, Lag= 0.0 min
Primary =
13.69 cfs @
12.08 hrs, Volume=
0.906 of
Routing by Stor-Ind method, Time Span= 5.00-120.00 hrs, dt= 0.05 hrs
Peak Elev= 300.97'@ 12.08 hrs
Device Routing Invert Outlet Devices
#1 Primary 300.00' 4.5' long Sharp -Crested Rectangular Weil End Contraction(s)
#2 Device 1 299.00' 54.0" x 60.0' long Barrel 1 (Low Flow)
RCP, square edge headwall, Ke= 0.500
Outlet Invert= 297.20' S= 0.0300 T Cc= 0.900
n= 0.012 Concrete pipe, finished
Primary OutFlowMax=13.42 cfs@ 12.08 hrs HW=300.95' (Free Discharge)
L1=Sharp-Crested Rectangular WeioWeir Controls 13.42 cfs @ 3.19 fps)
L2=Barrel 1 (Low Flow)(Passes 13.42 cfs of 26.06 cfs potential flow)
Pond C3: Culvert 3
Hydrograph
13.69 cfs
--i --------------------------------------------
-----------
I I
-' - -- -- -- -- -- -- -- -- -- --- Peak- lev=3 Q191' -
1--4--I--I--I---------------------------L-----L--
-------------------------------------------I---7----7__
I --L -L--L--1--1--1--1--1--L--L--L---------------------------L-----L--
-
t--t--t--t--t--t--t--t--t--t---I---
------------r--r--r--r--r--r--
-i - -- -- -- -- -- ------------------------------------ -- - - -i --
--7-7--7--T--T--T--7--7--7--7--7---------------------------7--I --7--
I I I I I I I
5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 105 110 115 120
Time (hours)
— Inflow
Primary

CREEK CROSSING 3
DEP Cary C3 Type 1124-hr 2-yr 24 hour Rainfall=3.45"
Prepared by Appian Consulting Engineers, PA Page 3
HydroCADO 8.00 s/n 003961 © 2006 HydroCAD Software Solutions LLC 6/7/2023
Subcatchment 3: Into Culvert 3
Inflow Hydrograph
Runoff = 19.47 cfs @ 12.08 hrs, Volume= 1.273 af, Depth= 1.53"
Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-120.00 hrs, dt= 0.05 hrs
Type II 24-hr 2-yr 24 hour Rainfall=3.45"
Area (ac) CN Description
1.000 55 Woods, Good, HSG B
3.000 85 Gravel
3.000 61 >75% Grass cover, Good, HSG B
3.000 98 Paved roads
10.000
79 Weighted Average
7.000
Pervious Area
3.000
Impervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
15.0 1,200 1.33 Direct Entry, Site Flow
Subcatchment 3: Into Culvert 3
Hydrograph
�1--L--L--1--1--L--L--L---I---I---I---I---I---L--L--L--1--1--L--�--�---I---I---
70 19.47ds -+--+--+--+--+------------------+--+--+--+--+--+--+--+------I---
19 r r--t--t--r--r--r---I---I---I---r--r--r--r--r/-�-wr--r--/art--err-/-�rw---I^-'-,I---
18 --r-r--t--t--r--r--r---------------I-Type-H,2-4-hr 2-yr 24hIaur--
17 --T -T-- -- -- ------------------------I, r r T16 -- - -- -- --------------------Ii-----Ii -- -- --
,5 --L-L--1--1--L--L--L------------------LR --ipff ---L= 0 aIIc-- 14 -- ---+--+-- -- -- ---------------I--- -- - - --
13 --+-+--+--+-- -- ------------------- iuno�f /O�a1ne=1 271
12 --r- r--t-- t-- r-- r-- r------------r--r--r--r--r--rw-#r--r--r--r- --I --C II ----
11 --T- T--T- -T -- -- -----------I---I-----T--T-Rui10#f Depth-1 --
8 __L _L__L 1 L L L __I I - - -IL IL L--L--L _
7 = = + + = ------------I-- L L = = 1a/- -/�wwFm n
6 --r-r--T--T-- -- --------------------r--r--r--+--+--+--1--CNY=7Ii9--
5 r r--T--T------------ I---I---I---r--r--r--r--r--r--r------ ------I---I---
4 --II- ---------------------------------------------------------II---
3 --' -' --' --' -- '---I---I---II---II---II---Ii--II---Ii --' --' --' --' --' -- '-- '---II---II---
2�I---II---II---
5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 105 110 115 120
Time (hours)
— Runoff

CREEK CROSSING 3
DEP Cary C3 Type 1124-hr 2-yr 24 hour Rainfall=3.45"
Prepared by Appian Consulting Engineers, PA Page 4
HydroCADO 8.00 s/n 003961 © 2006 HydroCAD Software Solutions LLC 6/7/2023
Pond C3: Culvert 3
Inflow Area =
10.000 ac,
Inflow Depth = 1.53"
for 2-yr 24 hour event
Inflow =
19.47 cfs @
12.08 hrs, Volume=
1.273 of
Outflow =
19.47 cfs @
12.08 hrs, Volume=
1.273 af, Atten= 0%, Lag= 0.0 min
Primary =
19.47 cfs @
12.08 hrs, Volume=
1.273 of
Routing by Stor-Ind method, Time Span= 5.00-120.00 hrs, dt= 0.05 hrs
Peak Elev= 301.23'@ 12.08 hrs
Device Routing Invert Outlet Devices
#1 Primary 300.00' 4.5' long Sharp -Crested Rectangular Weil End Contraction(s)
#2 Device 1 299.00' 54.0" x 60.0' long Barrel 1 (Low Flow)
RCP, square edge headwall, Ke= 0.500
Outlet Invert= 297.20' S= 0.0300 T Cc= 0.900
n= 0.012 Concrete pipe, finished
Primary OutFlowMax=19.10 cfs@ 12.08 hrs HW=301.21' (Free Discharge)
L1=Sharp-Crested Rectangular WeioWeir Controls 19.10 cfs @ 3.60 fps)
L2=Barrel 1 (Low Flow)(Passes 19.10 cfs of 35.16 cfs potential flow)
Pond C3: Culvert 3
Hydrograph
�1--L--L--L--1--1--1--L--L-- -- -----'---'------------'---'---'---L-----L--
19.47 cfs
19 r r--r--r--r--r--r--r--r--r--r---i---i---i---i---i---r--r--r--r--r--r--
18 --r-r--r--r--r--r--r--r--r--r--r----Inflow -Area=14-009 ac -
16 --li - -- -- -- -- -- -- ------------il---
15 --L-L--L--L--L--L--L--L--L--L--L------'---' ---------------L-----L--
14 --+ -+--+--+--+--+--+--+--+--+--+---------------------------+-----+--
12 --r -r--r--r--r--r--r--r--r--r--r------------------r--r--r--r-----r--
11 r r--r--T--T--T--T --T
-- -- -- ---i- - - - - rrr--T--i --r--
10 - -
li - -- -- -- -- -- -----------------------------------li --li --li --
8 --L -L--L--L--L--L--L--L--L--L--L---'------------------------L-----L--
7 --+ -+--+--+--+--+--+--+--+--+--+---i---i---i---i---i---i---i---i---+--i---+--
i
5 r r--I
-T--T--T------------------i---i---i---i---i---r--r--r--r--r--r--
4 --,-ij
3 21 --L L---1--1--1--L--L--L--L--L---'------------------------L-----L--
5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 105 110 115 120
Time (hours)
— Inflow
Primary

CREEK CROSSING 3
DEP Cary C3 Type 1124-hr 10-yr 24 hour Rainfall=5.01 "
Prepared by Appian Consulting Engineers, PA Page 5
HydroCADO 8.00 s/n 003961 © 2006 HydroCAD Software Solutions LLC 6/7/2023
Subcatchment 3: Into Culvert 3
Inflow Hydrograph
Runoff = 36.06 cfs @ 12.07 hrs, Volume= 2.342 af, Depth= 2.81"
Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-120.00 hrs, dt= 0.05 hrs
Type II 24-hr 10-yr 24 hour Rainfall=5.01"
Area (ac) CN Description
1.000 55 Woods, Good, HSG B
3.000 85 Gravel
3.000 61 >75% Grass cover, Good, HSG B
3.000 98 Paved roads
10.000
79 Weighted Average
7.000
Pervious Area
3.000
Impervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
15.0 1,200 1.33 Direct Entry, Site Flow
Subcatchment 3: Into Culvert 3
Hydrograph
-- ----------
i36.06cfs
- --
--
--
--
--
--
------------------
------------------
-- -- -- -- -- -- -----------
-- -- -- -- -- -- -----------
--
---+--+--
--
--
---------------'-Type-H,2
-hr-1�-yr 24-houir -
_ iZal uafal 1=&01' "- -
i ---
----
--
--
--
--
------------,
--,--- -Runoff Are+a=40'000-arc -
--+
-+--+--+--
--
--
---'---'---'---'------
+-Rgnoff+Vg1ume�=2+.342-af -
i --
---+--+--
--
--
----------------------+--Oowte-n-1-
0 ��--
1 __+
_+__+__+--------------------------�__�__+__+------------I---
- - +
i --+
--}
- - -
-+--+--+--
-}--+--+--
- + -
- + -
- 4-
--
--
- -
--
--
- - - - - - - - -
-
-----I- -
--------
- - - - - - - - - - - - 1 - - I - - + - - + - - + - - '1 -
- I - - - I - - -I--- -- I - - I - - + - - + -- 4-- -- ------I---
-----
5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 105 110 115 120
Time (hours)
— Runoff

CREEK CROSSING 3
DEP Cary C3 Type 1124-hr 10-yr 24 hour Rainfall=5.01 "
Prepared by Appian Consulting Engineers, PA Page 6
HydroCADO 8.00 s/n 003961 © 2006 HydroCAD Software Solutions LLC 6/7/2023
Pond C3: Culvert 3
Inflow Area =
10.000 ac,
Inflow Depth = 2.81"
for 10-yr 24 hour event
Inflow =
36.06 cfs @
12.07 hrs, Volume=
2.342 of
Outflow =
36.06 cfs @
12.07 hrs, Volume=
2.342 af, Atten= 0%, Lag= 0.0 min
Primary =
36.06 cfs @
12.07 hrs, Volume=
2.342 of
Routing by Stor-Ind method, Time Span= 5.00-120.00 hrs, dt= 0.05 hrs
Peak Elev= 301.87'@ 12.07 hrs
Device Routing Invert Outlet Devices
#1 Primary 300.00' 4.5' long Sharp -Crested Rectangular Weil End Contraction(s)
#2 Device 1 299.00' 54.0" x 60.0' long Barrel 1 (Low Flow)
RCP, square edge headwall, Ke= 0.500
Outlet Invert= 297.20' S= 0.0300 T Cc= 0.900
n= 0.012 Concrete pipe, finished
Primary OutFlowMax=35.36 cfs@ 12.07 hrs HW=301.84' (Free Discharge)
L1=Sharp-Crested Rectangular WeioWeir Controls 35.36 cfs @ 4.44 fps)
L2=Barrel 1 (Low Flow)(Passes 35.36 cfs of 60.85 cfs potential flow)
Pond C3: Culvert 3
Hydrograph
38
36
-+--+--+--+--+--+--+--+--+--+--+--+--------------
---+--+--+--
--
--
--
--
---------------------------
----- --
+�--+--+/�--+--+--
36.06cfs
--+
34
--
- --
--+--+--+--
--+--
--
--
---
-InflowArea-,1 G.-009 Cap
26
--+
-+--+--+--+--+--+--+--+--+--+---------------------------+-----+--
24
--+
-+--+--+--+--+--+--+--+--+--+--+--+--+--+--+---+--+--+--+--+--+--
16
--+
-+--------------+--+--+--+--+--+--+--+--+--+---+--+--+--+--+--+--
8
--+II
+--------------+--+--+--+--+--+--+--+--+--+---+--+--+--+--+--+--
6
--++--+--------------+--+--+--+--+--+--+--+--+--+---+--+--+--+--+--+--
5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 105 110 115 120
Time (hours)
— Inflow
Primary

CREEK CROSSING 3
DEP Cary C3 Type // 24-hr 25-yr 24 hour Rainfall=5.93"
Prepared by Appian Consulting Engineers, PA Page 7
HydroCADO 8.00 s/n 003961 © 2006 HydroCAD Software Solutions LLC 6/7/2023
Subcatchment 3: Into Culvert 3
Inflow Hydrograph
Runoff = 46.25 cfs @ 12.07 hrs, Volume= 3.014 af, Depth= 3.62"
Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-120.00 hrs, dt= 0.05 hrs
Type II 24-hr 25-yr 24 hour Rainfall=5.93"
Area (ac) CN Description
1.000 55 Woods, Good, HSG B
3.000 85 Gravel
3.000 61 >75% Grass cover, Good, HSG B
3.000 98 Paved roads
10.000
79 Weighted Average
7.000
Pervious Area
3.000
Impervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
15.0 1,200 1.33 Direct Entry, Site Flow
Subcatchment 3: Into Culvert 3
Hydrograph
-- ----+--+-- -- -- ---------------I--- -- -- -- -- ------------
46.. 5 cfs
Type IIII 24-hr 25-yl,r 24 hour
-
r--t--t--r--r--r------------r-----r--r--r--r rRQinfal1-5.93'-
i --r-r--T--T-- -- -----------I---�-----r- -Rtuh-off Area-,'f9790n-a�E
I --! -! --! --! -- -- -- ---III---III---III---II, --III---IIrRuno_ff_TVolume� l 011114 -af -
Runoff 0epthlll=31I�6�"
i --i -i--T--T-----------------I---i--I---i --i----------- -- -- I------
�Iow IlLeugth=1,200'
cT 5. -ImiI -
-L--1--1--1--J--J---1---1---1---1---1---L--L--L--1--1--1--�--�---I---I---
5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 105 110 115 120
Time (hours)
— Runoff

CREEK CROSSING 3
DEP Cary C3 Type // 24-hr 25-yr 24 hour Rainfall=5.93"
Prepared by Appian Consulting Engineers, PA Page 8
HydroCADO 8.00 s/n 003961 © 2006 HydroCAD Software Solutions LLC 6/7/2023
Pond C3: Culvert 3
Inflow Area =
10.000 ac,
Inflow Depth = 3.62"
for 25-yr 24 hour event
Inflow =
46.25 cfs @
12.07 hrs, Volume=
3.014 of
Outflow =
46.25 cfs @
12.07 hrs, Volume=
3.014 af, Atten= 0%, Lag= 0.0 min
Primary =
46.25 cfs @
12.07 hrs, Volume=
3.014 of
Routing by Stor-Ind method, Time Span= 5.00-120.00 hrs, dt= 0.05 hrs
Peak Elev= 302.22'@ 12.07 hrs
Device Routing Invert Outlet Devices
#1 Primary 300.00' 4.5' long Sharp -Crested Rectangular Weil End Contraction(s)
#2 Device 1 299.00' 54.0" x 60.0' long Barrel 1 (Low Flow)
RCP, square edge headwall, Ke= 0.500
Outlet Invert= 297.20' S= 0.0300 T Cc= 0.900
n= 0.012 Concrete pipe, finished
Primary OutFlowMax=45.38 cfs@ 12.07 hrs HW=302.19' (Free Discharge)
L1=Sharp-Crested Rectangular WeioWeir Controls 45.38 cfs @ 4.84 fps)
L2=Barrel 1 (Low Flow)(Passes 45.38 cfs of 73.32 cfs potential flow)
Pond C3: Culvert 3
Hydrograph
46.25 cfs
- Inflowarea-10.0��00 arc
i--�i-- --- - -- -- -- -- -- -- -- ------------------------------ - --- -F
--�- - � -- � -- � -- � -- � -- � -- � -- �-- �-- �---�i---�i---�i---�i---�i---�i---�i---it---li --li --� --
--LUI--1--+--+--+-------------------------------------L-----L--
5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 105 110 115 120
Time (hours)
— Inflow
Primary

CREEK CROSSING 3
DEP Cary C3 Type 1124-hr 50-yr 24 hour Rainfall=6.67"
Prepared by Appian Consulting Engineers, PA Page 9
HydroCADO 8.00 s/n 003961 © 2006 HydroCAD Software Solutions LLC 6/7/2023
Subcatchment 3: Into Culvert 3
Inflow Hydrograph
Runoff = 54.54 cfs @ 12.07 hrs, Volume= 3.570 af, Depth= 4.28"
Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-120.00 hrs, dt= 0.05 hrs
Type II 24-hr 50-yr 24 hour Rainfall=6.67"
Area (ac) CN Description
1.000 55 Woods, Good, HSG B
3.000 85 Gravel
3.000 61 >75% Grass cover, Good, HSG B
3.000 98 Paved roads
10.000
79 Weighted Average
7.000
Pervious Area
3.000
Impervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
15.0 1,200 1.33 Direct Entry, Site Flow
Subcatchment 3: Into Culvert 3
Hydrograph
54.54 cfs
i --+-+--+--+--7-------------I---i -------r--r--+--+--7----------I---
-+-+--+--+--L--L-- ---' Tyke-IJ!2Jhr_56-xC214-o -
-I -- I -- IRaiinfall'I-6.67"__L--LI --LI -- -- ---------I--- --I--- --Runoff Area=1O,,OOo_arc
Runoff 'Volullrn&l.57O of
--L-L--L--L--L--L--J---'---'---'---'---'---'L--L--Rupoff_0epth'--- --..--
.. �Iqw ,Length=1,�0-0'- -
TcT15.0 lmin
CN=79
5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 105 110 115 120
Time (hours)
— Runoff

CREEK CROSSING 3
DEP Cary C3 Type 1124-hr 50-yr 24 hour Rainfall=6.67"
Prepared by Appian Consulting Engineers, PA Page 10
HydroCADO 8.00 s/n 003961 © 2006 HydroCAD Software Solutions LLC 6/7/2023
Pond C3: Culvert 3
Inflow Area =
10.000 ac,
Inflow Depth = 4.28"
for 50-yr 24 hour event
Inflow =
54.54 cfs @
12.07 hrs, Volume=
3.570 of
Outflow =
54.54 cfs @
12.07 hrs, Volume=
3.570 af, Atten= 0%, Lag= 0.0 min
Primary =
54.54 cfs @
12.07 hrs, Volume=
3.570 of
Routing by Stor-Ind method, Time Span= 5.00-120.00 hrs, dt= 0.05 hrs
Peak Elev= 302.49'@ 12.07 hrs
Device Routing Invert Outlet Devices
#1 Primary 300.00' 4.5' long Sharp -Crested Rectangular Weil End Contraction(s)
#2 Device 1 299.00' 54.0" x 60.0' long Barrel 1 (Low Flow)
RCP, square edge headwall, Ke= 0.500
Outlet Invert= 297.20' S= 0.0300 T Cc= 0.900
n= 0.012 Concrete pipe, finished
Primary OutFlowMax=53.55 cfs@ 12.07 hrs HW=302.46' (Free Discharge)
L1=Sharp-Crested Rectangular WeioWeir Controls 53.55 cfs @ 5.12 fps)
L2=Barrel 1 (Low Flow)(Passes 53.55 cfs of 82.96 cfs potential flow)
Pond C3: Culvert 3
Hydrograph
54.54 cfs
i --r-r--r--T--T--T--7--7---------li---li---li-`-.n-Irn-nli--yr.--
Peak-PEev=,U2!9-
-+--+--+--+--+--+--+--+--+--+---------------------------+-----+--
--�- - � -- � -- � -- � -- � -- � -- � -- �-- �-- �---�i---�i---�i---�i---�i---�i---�i---it---li --li --� --
5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 105 110 115 120
Time (hours)
— Inflow
Primary

CREEK CROSSING 3
DEP Cary C3 Type 1124-hr 100-yr 24 hour Rainfall=7.41 "
Prepared by Appian Consulting Engineers, PA Page 11
HydroCADO 8.00 s/n 003961 © 2006 HydroCAD Software Solutions LLC 6/7/2023
Subcatchment 3: Into Culvert 3
Inflow Hydrograph
Runoff = 62.89 cfs @ 12.07 hrs, Volume= 4.134 af, Depth= 4.96"
Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-120.00 hrs, dt= 0.05 hrs
Type II 24-hr 100-yr 24 hour Rainfall=7.41"
Area (ac) CN Description
1.000 55 Woods, Good, HSG B
3.000 85 Gravel
3.000 61 >75% Grass cover, Good, HSG B
3.000 98 Paved roads
10.000
79 Weighted Average
7.000
Pervious Area
3.000
Impervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
15.0 1,200 1.33 Direct Entry, Site Flow
Subcatchment 3: Into Culvert 3
Hydrograph
62.89ds -r--r--r--r--r---------r--r--r--r--r--r--r--r--r--r--r--r--r---
I --�, - -- -- --------------------�, --- Tyre-U-24�; hr, 00--y/rr�-4�ovr-
-;----------------------- - - -T -Rai0faH=-7.-4jiF-
Runoff Areec
--L-L--1--1--1--J--J---1---1---�---�---�---L- L--L--1--1--1--�--�---�---�---
Runoff Vlolume=4.134 of
--L-L--L--L--L--L--J---1---1---1---1---1---L--L--L--1--1--L----------�---
- Runoff IDeoth=4.96" -
FlloW L6ncAthr1,',2OO'
--r-r--t--t--rt--y--y------------------r--r- r--+--+--rt--
Tcr 16.0 l m iln
-;---,---,---'---'---'---'---'---'---r--r--T -- --
---------------------------------
--L-L--1--1--1--J-----1---1---1---1---1---L--L--L--1--1--1----------�---
5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 105 110 115 120
Time (hours)
— Runoff

CREEK CROSSING 3
DEP Cary C3 Type 1124-hr 100-yr 24 hour Rainfall=7.41 "
Prepared by Appian Consulting Engineers, PA Page 12
HydroCADO 8.00 s/n 003961 © 2006 HydroCAD Software Solutions LLC 6/7/2023
Pond C3: Culvert 3
Inflow Area =
10.000 ac,
Inflow Depth = 4.96"
for 100-yr 24 hour event
Inflow =
62.89 cfs @
12.07 hrs, Volume=
4.134 of
Outflow =
62.89 cfs @
12.07 hrs, Volume=
4.134 af, Atten= 0%, Lag= 0.0 min
Primary =
62.89 cfs @
12.07 hrs, Volume=
4.134 of
Routing by Stor-Ind method, Time Span= 5.00-120.00 hrs, dt= 0.05 hrs
Peak Elev= 302.75'@ 12.07 hrs
Device Routing Invert Outlet Devices
#1 Primary 300.00' 4.5' long Sharp -Crested Rectangular Weil End Contraction(s)
#2 Device 1 299.00' 54.0" x 60.0' long Barrel 1 (Low Flow)
RCP, square edge headwall, Ke= 0.500
Outlet Invert= 297.20' S= 0.0300 T Cc= 0.900
n= 0.012 Concrete pipe, finished
Primary OutFlowMax=61.77 cfs@ 12.07 hrs HW=302.71' (Free Discharge)
L1=Sharp-Crested Rectangular WeioWeir Controls 61.77 cfs @ 5.39 fps)
L2=Barrel 1 (Low Flow)(Passes 61.77 cfs of 92.07 cfs potential flow)
Pond C3: Culvert 3
Hydrograph
62.89 cfs
i -r--r--r--r--r--r--r--r--r---i---i---i---i---i---i---i---i---r--r--r--
I -- - -- -- -- -- -- -- -- -- -----��-tn l-bV1M re���a 1Q-000i aic -
i--�,- ----il __ __ _ -------------------------
--li - -- -- -- -- -- ---------------------------------- -li --li - -li --
i --�- - � -- � -- � -- � -- � -- � -- � -- �-- �-- �---�i---�i---�i---�i---�i---�i---�i---it---li --li --� --
--L -L--L--1--1--1--L--1--L--L--L---------------------------L-----L--
5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 105 110 115 120
Time (hours)
— Inflow
Primary

CREEK CROSSING 3
DEP Cary C3 Type // 24-hr 500-yr 24 hour Rainfall=9.22"
Prepared by Appian Consulting Engineers, PA Page 13
HydroCADO 8.00 s/n 003961 © 2006 HydroCAD Software Solutions LLC 6/7/2023
Subcatchment 3: Into Culvert 3
Inflow Hydrograph
Runoff = 83.38 cfs @ 12.07 hrs, Volume= 5.544 af, Depth> 6.65"
Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-120.00 hrs, dt= 0.05 hrs
Type II 24-hr 500-yr 24 hour Rainfall=9.22"
Area (ac) CN Description
1.000 55 Woods, Good, HSG B
3.000 85 Gravel
3.000 61 >75% Grass cover, Good, HSG B
3.000 98 Paved roads
10.000
79 Weighted Average
7.000
Pervious Area
3.000
Impervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
15.0 1,200 1.33 Direct Entry, Site Flow
Subcatchment 3: Into Culvert 3
Hydrograph
I--L--L--1--1--1--J--J---1---1---1---1---1---L--L--L--1--1--1--�--�---1---1---
83.38 cfs
---------------------------------
I--lTI
- T--T--T---------------- TYpIP-111-24; hr 0=y/r -or-
I --r-T--T--T--7--7--7---1------I---I --I---r--r--r--T--T--7--,--,--Q-1---I---
--T-T--T--T--T--T--T---li---li---li---li---li---lr--T--T--T--T�infa"=19.22"-
--+-+--+--+-- -- --------------------'r---Runof Area--1O1.O00-ac-
--L Rurlo-ff Volulme_=_5.544 of -
--1-Runoff D"th>6f5"-
i --1, -1, -- T -- T -- T--T--T---1---1---1---1,--1---1, --'� --'� F r Iov�L�n��hr1-120
- - - 7 - - - r--T__T__7__7--7---I___I___I___I___I___r__r__r__T__T__7__ 7---I
i --r-r--+--+----__ __ ----------T&15:0-lMiln--
--� ---+--+-- -- -----1---1---1---1---1--- -- -- -- -- -- --'- GNC 75-
i --L-L--1--1--1--J--�---1---1---1---1---1---L--L--L--1--1--1--�--�---1--_1---
i --1- -1---=--=---1---1---1---11---11---11---11---11---11---1---1---1---1----1---1---1---11---11---
--1- -1----1---1---1---1---1---1---1---1---1---1---1---1---1---1---1----11---1---1---1---1---
i --r r--r--r--r--r--r---1---1---1---r--1---r--r--r--r--r--r--r--r---1---1---
5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 105 110 115 120
Time (hours)
— Runoff

CREEK CROSSING 3
DEP Cary C3 Type // 24-hr 500-yr 24 hour Rainfall=9.22"
Prepared by Appian Consulting Engineers, PA Page 14
HydroCADO 8.00 s/n 003961 © 2006 HydroCAD Software Solutions LLC 6/7/2023
Pond C3: Culvert 3
Inflow Area =
10.000 ac,
Inflow Depth > 6.65"
for 500-yr 24 hour event
Inflow =
83.38 cfs @
12.07 hrs, Volume=
5.544 of
Outflow =
83.38 cfs @
12.07 hrs, Volume=
5.544 af, Atten= 0%, Lag= 0.0 min
Primary =
83.38 cfs @
12.07 hrs, Volume=
5.544 of
Routing by Stor-Ind method, Time Span= 5.00-120.00 hrs, dt= 0.05 hrs
Peak Elev= 303.35'@ 12.07 hrs
Device Routing Invert Outlet Devices
#1 Primary 300.00' 4.5' long Sharp -Crested Rectangular Weil End Contraction(s)
#2 Device 1 299.00' 54.0" x 60.0' long Barrel 1 (Low Flow)
RCP, square edge headwall, Ke= 0.500
Outlet Invert= 297.20' S= 0.0300 T Cc= 0.900
n= 0.012 Concrete pipe, finished
Primary OutFlowMax=81.98 cfs@ 12.07 hrs HW=303.31' (Free Discharge)
L1=Sharp-Crested Rectangular WeioWeir Controls 81.98 cfs @ 5.95 fps)
L2=Barrel 1 (Low Flow)(Passes 81.98 cfs of 110.70 cfs potential flow)
Pond C3: Culvert 3
Hydrograph
--L--L--L--1--1--1--1--1---------'---'------------I---I---I---L-----L--
83.38 cfs
41III---�-Inflow Area=10.-000- aic -
i --r -r--r--r--r--r--r--r--r--r--r--r--r
--r------------------r--r--r--
I --;-;--;--;--;--;--;--;--;--;--;---------IIPea-k-P.tev=3i0 !36`-
-r--r--+--+--+----+--1--1--1---------------
------------r-----r--
--r -r--r--r--r--r--r--r--r--r--r---I------------I---I---I---I---r-----r--
i --r -r--r--+--+--+------+--1--1--1---------------------------r-----r--
i --L -L--L--1--1--1--1--1--L--L--L---------------------------L-----L--
--L -� --�--1__1__1__1-_1-- �-- �-- �---I---I---I---I---I---I---I---I---I---I--_r --
i --I- - � -- � -- � -- � -- � -- � -- � -- �-- �-- �---II---II---II---II---II---II---II---II---Ii --Ii --� --
--rr-
-----------------------I- - -i --r - -i
r--r--r--r--r--r--r--r--r--r---I---I---I---I---I---I---I---I---r--r--r--
5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 105 110 115 120
Time (hours)
— Inflow
Primary

CREEK CROSSING 3
DEP Cary C3 Type 1124-hr 1000-yr 24 hour Rainfall=10.00"
Prepared by Appian Consulting Engineers, PA Page 15
HydroCADO 8.00 s/n 003961 © 2006 HydroCAD Software Solutions LLC 6/7/2023
Subcatchment 3: Into Culvert 3
Inflow Hydrograph
Runoff = 92.22 cfs @ 12.06 hrs, Volume= 6.160 af, Depth> 7.39"
Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-120.00 hrs, dt= 0.05 hrs
Type II 24-hr 1000-yr 24 hour Rainfall=10.00"
Area (ac) CN Description
1.000 55 Woods, Good, HSG B
3.000 85 Gravel
3.000 61 >75% Grass cover, Good, HSG B
3.000 98 Paved roads
10.000
79 Weighted Average
7.000
Pervious Area
3.000
Impervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
15.0 1,200 1.33 Direct Entry, Site Flow
Subcatchment 3: Into Culvert 3
Hydrograph
- - + - - + - - + - - + - - + - - +
92.22cfs-+--r--+--+--+--+--+--+--+--+----n-----------------�i----4h--iogr---i---
r-1 006�
--r-r--r--r--r--r--r--r--r--r--r--r-`
--T-T--T--T--T--T--T--T--T--T-- -----------------Relin:eo-,-
--r -r--r--r--r--r--r--r--r--r--r--r---------------------r--r--r
--r--
--T- T--T--T--T--T--T-- -- ---------------Runpff-Arga=0,000 cjk-
-F T--T--T--T--T--T--T--T--T--;--;-----uo#fivoi0m=6
- - -- -- Runof�''De'pt1�7.3g"_
-------------------- -- -- -- -- AowLen =1
- - -
-------------------- -- -- -- -- ------------------------ICU=7'9--
5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 105 110 115 120
Time (hours)
— Runoff

CREEK CROSSING 3
DEP Cary C3 Type 1124-hr 1000-yr 24 hour Rainfall=10.00"
Prepared by Appian Consulting Engineers, PA Page 16
HydroCADO 8.00 s/n 003961 © 2006 HydroCAD Software Solutions LLC 6/7/2023
Pond C3: Culvert 3
Inflow Area =
10.000 ac,
Inflow Depth > 7.39"
for 1000-yr 24 hour event
Inflow =
92.22 cfs @
12.06 hrs, Volume=
6.160 of
Outflow =
92.22 cfs @
12.06 hrs, Volume=
6.160 af, Atten= 0%, Lag= 0.0 min
Primary =
92.22 cfs @
12.06 hrs, Volume=
6.160 of
Routing by Stor-Ind method, Time Span= 5.00-120.00 hrs, dt= 0.05 hrs
Peak Elev= 303.59'@ 12.07 hrs
Device Routing Invert Outlet Devices
#1 Primary 300.00' 4.5' long Sharp -Crested Rectangular Weil End Contraction(s)
#2 Device 1 299.00' 54.0" x 60.0' long Barrel 1 (Low Flow)
RCP, square edge headwall, Ke= 0.500
Outlet Invert= 297.20' S= 0.0300 T Cc= 0.900
n= 0.012 Concrete pipe, finished
Primary OutFlowMax=90.70 cfs@ 12.06 hrs HW=303.55' (Free Discharge)
L1=Sharp-Crested Rectangular WeioWeir Controls 90.70 cfs @ 6.16 fps)
L2=Barrel 1 (Low Flow)(Passes 90.70 cfs of 116.17 cfs potential flow)
Pond C3: Culvert 3
Hydrograph
92.22ds _+ r--r--r--r--r--r--r--r--+--+--+--+--+--+--+--+--+--+--+--
--r-r--r--Y--Y--Y--Y--Y--Y--Y--Y--r _`N`r_Jw�r _�/r�r_J/�rJ _(/_J�YJ�_�(/��Y _�/_y�
--r-
r--r--r--r--r--r--r--r--r--r--rI ■fl-owQArea--1 V.00V' MC•
=-r-r--r--r--r--r--r--r--r--r--r--r--r--,P$��( ���irVT��r�, -
-r -r--r--r--r--r--r--r--r--r--r--r--r--
r - r - - r - - r - - r - - r - - r - - r - - r - - r - - r - - T - - r - - r - - r - - r - - r - - r - - r - - + - - + - -
- - r - r - - r - - r - - r - - r - - r - - r - - r - - r - - r - - T - - r - - r - - r - - r - - r - - r - - r - - + - - + - - + - -
I I I I I I I I I I I I I I I I I I I I I I
--IL -IL--IL--L--L--L--L--L--L--L--L--1--L--L--L--L--L--L--L--1--1--L--
--IL -IL--IL--L--L--L--L--L--L--L--L--1--L--L--L--L--L--L--L--1--1--L--
-- - -- --L--L--L--L--L--L--L--L--i--i--i--i--i--i--i--i--+--+--+--
5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 105 110 115 120
Time (hours)
— Inflow
Primary

EROSION CONTROL CALCULATIONS
AVAILABLE UPON REQUEST

APPENDIX

NCDEQ Stormwater Design Manual
Environmental
Quality
A-4. Built -Upon Area
N.C.G.S.143-214.7(b2): For purposes of implementing stormwater programs, "built -upon area"
means impervious surface and partially impervious surface to the extent that the partially
impervious surface does not allow water to infiltrate through the surface and into the subsoil.
"Built -upon area" does not include:
- a slatted deck;
- the water area of a swimming pool;
- a surface of number 57 stone, as designated by the American Society for Testing and
Materials, laid at least four inches thick over a geotextile fabric;
- a trail as defined in G.S. 113A-85 that is either unpaved or paved as long as the
pavement is porous with a hydraulic conductivity greater than 0.001 centimeters per
second (1.41 inches per hour); or
- landscaping material, including, but not limited to, gravel, mulch, sand, and vegetation,
placed on areas that receive pedestrian or bicycle traffic or on portions of driveways and
parking areas that will not be compacted by the weight of a vehicle, such as the area
between sections of pavement that support the weight of a vehicle.
The owner or developer of a property may opt out of any of the exemptions from "built -upon
area" set out in this subsection.
NOTE: The above definition of "built -upon area" applies only to state stormwater programs.
Some additional guidance on using #57 stone in accordance with the statute is as follows:
• The #57 stone may not be mixed with other aggregate material;
• "Geotextile fabric" means a permeable geosynthetic comprised solely of non -
biodegradable textiles. [15A NCAC 2H .1002(19)]
• The #57 stone and geotextile fabric may not be placed on top of an impervious material,
such as crusher run or asphalt;
• The #57 stone area may not use an underdrain system that discharges without
treatment; and
• The soil on which the 57 stone will be placed (subgrade) should not be mechanically
compacted prior to installation; however, the statute does not prohibit this.
A-4. Built -Upon Area 1 Revised: 2-11-2018

K�CEn vironmental
NCDEQ Stormwater Design Manual Quality
Figure 1: Number 57 Stone
Although #57 stone laid on geotextile fabric and trails that meet the minimum hydraulic
conductivity standard are not considered built -upon area to determine whether a project is high
density or low density, these areas shall be accounted for in the design of SCMs required in
high density projects. Per 15A NCAC 02H .1050, SCMs shall be sized to account for runoff
from all surfaces draining to the system unless the applicant can demonstrate that those areas
will not produce stormwater runoff. The requirement to account for runoff from all surfaces for
purposes of SCM sizing is consistent with rule 15A NCAC 2H .1003(3).
Any size stone or aggregate used on portions of projects that receive infrequent vehicular traffic
(approximately twice a month or less) may be counted as pervious regardless of the depth of
the stone layer. This includes applications such as decorative landscaping, drainage swales,
weed control, and the area within the fenced yard at electrical substations.
If an applicant plans to install a surface that does not meet one of the five exemptions to built -
upon area called out in N.C.G.S.143-214.7(b2), he has the option of demonstrating to the
permitting authority that the proposed surface allows an adequate level of stormwater infiltration
to be considered either pervious or partially pervious. The information the applicant provides
shall be based on engineering calculations and the results of research studies showing that the
proposed surface provides equal or better infiltration rates as the surrounding pervious surfaces
and that it shall function in perpetuity.
A-4. Built -Upon Area 2 Revised: 2-11-2018

8/24/22, 11:00 AM
Precipitation Frequency Data Server
NOAA Atlas 14, Volume 2, Version 3
Location name: Cary, North Carolina, USA* t
Latitude: 35.784*, Longitude:-78.8881*
Elevation: 332.52 ft**
*source: ESRI Maps 'w,�w,
source: USGS
POINT PRECIPITATION FREQUENCY ESTIMATES
G.M. Bonnin, D. Martin, B. Lin, T. Parzybok, M.Yekta, and D. Riley
NOAA, National Weather Service, Silver Spring, Maryland
PF tabular I PF graphical I Maps & aerials
PF tabular
II PDS-based point precipitation freauencv estimates with 90% confidence intervals (in inches)" II
Average recurrence interval (years)
1 2 5 10 25 50 100 200 500 1000
5-min 0.403 0.472 0.541 0.600 0.661 0.705 0.745 0.778 0.815 0.844
(0.369-0.440) (0.432-0.515) (0.496-0.591) (0.549-0.654) (0.603-0.720) (0.640-0.768) (0.672-0.811) (0.699-0.848) (0.725-0.888) (0.745-0.921)
10-min 0.644 0.754 0.866 0.960 1.05 1.12 1.18 1.23 1.29 1.33
(0.590-0.702) (0.691-0.824) (0.795-0.946) (0.878-1.05) (0.960-1.15) 1 (1.02-1.22) 1 (1.07-1.29) 11 (1.11-1.35) 11 (1.15-1.41) 11 (1.17-1.45)
15-min 0.804 0.948 1.10 1.21 1.34 1.42 1.50 1.56 1.62 1.67
(0.738-0.878) (0.869-1.04) (1.01-1.20) 1 1 (1.22-1.46) 1 (1.29-1.55) 1 (1.35-1.63) 11 (1.40-1.70) 11 (1.44-1.77) 11 (1.47-1.82)
30-min 1.10 1.31 1.56 1.76 1.98 2.14 2.29 2.42 2.58 2.70
(1.01-1.20) (1.20-1.43) (1.43-1.70) (1.61-1.92) (1.80-2.15) (1.95-2.33) (2.07-2.49) (2.1 7-2.64) (2.30-2.81) (2.38-2.95)
60-min 1.38 1.64 2.00 2.29 2.63 2.90 3.16 3.40 3.70 3.94
(1.26-1.50) 11 (1.51-1.80) 11 (1.83-2.18) 11 (2.10-2.50) (2.40-2.87) (2.64-3.16) (2.85-3.44) (3.05-3.71) (3.30-4.04) (3.48-4.31)
2-hr 1.60 1.92 2.36 2.73 3.18 3.55 3.89 4.25 4.70 5.06
(1.46-1.76) 11 (1.75-2.11) 11 (2.15-2.59) (2.47-2.99) (2.86-3.48) (3.19-3.88) (3.48-4.27) (3.77-4.65) (4.13-5.14) (4.41-5.55)
3-hr 1.70 2.04 2.51 2.92 3.44 3.87 4.30 4.74 5.32 5.80
(1.55-1.87) 11 (1.86-2.24) (2.29-2.76) (2.66-3.21) (3.11-3.77) (3.48-4.24) (3.83-4.71) (4.20-5.18) (4.66-5.82) (5.03-6.36)
6-hr 2.04 2.45 3.02 3.53 4.17 4.71 5.25 5.81 6.57 7.21
(1.88-2.24) 1 1 (2.77-3.31) (3.22-3.85) (3.79-4.54) (4.25-5.13) (4.70-5.71) (5.15-6.32) (5.74-7.14) (6.23-7.84)
12-hr (2.23 2?64) (2.67 3017) (3. 0 3997) (3.85 4159) (4.565?45) (5. 5 6118) (5. 2 6194) (6.311573) (7.09 8682) (7.73 9477)
JL!4-_hr
2.86
11
3.45
11
4.33
5.01
5.93
11
6.67
11
7.41
8.17
9.22
10.0
(2.67-3.07)
(3.23-3.71)
(4.04-4.64)
(4.67-5.37)
(5.51-6.37)
(6.18-7.15)
(6.85-7.95) 11
(7.54-8.78)
(8.46-9.92)
(9.17-10.8)
uuuuuuuuu 1U11 11.1
2{iay (3.08-3.56) (3.72-4.28) (4.61-5.32) (5.30-6.12) (6.22-7.21) (6.93-8.06) (7.66-8.93) (8.39-9.83) (9.38-11.0)
3.49 4.20 5.19 5.96 7.01 7.84 8.68 9.54 10.7 11.6
3{iay (3.26-3.75) (3.92-4.50) (4.84-5.57) (5.55-6.40) (6.51-7.53) (7.26-8.41) (8.01-9.33) (8.78-10.3) (9.80-11.5) (10.6-12.5)
3.68 4.41 5.43 6.23 7.32 8.18 9.06 9.95 11.2 12.1
4{iay (3.44-3.94) (4.12-4.72) (5.07-5.81) (5.81-6.67) (6.80-7.85) (7.58-8.77) (8.36-9.72) (9.16-10.7) (10.2-12.0) (11.1-13.0)
4.24 5.06 6.16 7.02 8.20 9.14 10.1 11.1 12.4 13.4
7{iay (3.98-4.53) (4.75-5.40) (5.77-6.57) (6.57-7.49) (7.65-8.75) 1 (8.50-9.75) 1 (9.35-10.8) 11 (10.2-11.8) (11.4-13.3) (12.3-14.4)
10-day 4.84 5.75 6.91 7.82 9.04 9.99 11.0 11.9 13.2 14.3
(4.55-5.16) (5.40-6.13) (6.49-7.37) (7.33-8.33) (8.45-9.63) 1 (9.32-10.7) 1 (10.2-11.7) 11 (11.1-12.8) 11 (12.2-14.2) 11 (13.1-15.3)
20-day 6.46 7.62 9.00 10.1 11.6 12.7 13.9 15.1 16.7 18.0
(6.07-6.88) (7.17-8.11) (8.45-9.58) (9.47-10.7) (10.8-12.3) 1 (11.9-13.6) 1 (12.9-14.8) 11 (14.0-16.1) 11 (15.4-17.9) 11 (16.5-19.2)
30-day 8.01 9.43 11.0 12.1 13.7 14.9 16.1 17.3 18.9 20.0
(7.56-8.52) 11 (8.88-10.0) 11 (10.3-11.6) 1 (12.8-14.6) 1 (13.9-15.8) 1 (15.0-17.1) 11 (16.1-18.4) 11 (17.5-20.1) 11 (18.6-21.5)
45-day 10 1� 1� 1� 1� 1� 19.4
� 20.7
� 22.3
� 2�
(9.73-10.8) (11.4-12.7) (13.0-14.5) (14.3-15.9) (15.9-17.7) (17.1-19.1) (18.3-20.5) (19.4-21.9) (20.9-23.7) (22.0-25.1)
9.4
60-day (11172--12.9) (1316-15.1) (1514-127.0) (1617 18.5) (1814- 0.5) 11 (1920 8 0) (20.9-23.4) (22213 4.8) (23?6-26.5) (24?7--27.9)
1 Precipitation frequency (PF) estimates in this table are based on frequency analysis of partial duration series (PDS).
Numbers in parenthesis are PF estimates at lower and upper bounds of the 90% confidence interval. The probability that precipitation frequency estimates (for a
given duration and average recurrence interval) will be greater than the upper bound (or less than the lower bound) is 5%. Estimates at upper bounds are not
checked against probable maximum precipitation (PMP) estimates and may be higher than currently valid PMP values.
Please refer to NOAA Atlas 14 document for more information.
Back to Top
PF graphical
https://hdsc.nws.noaa.gov/hdsc/pfds/pfds_printpage.htmI?Iat=35.7840&Ion=-78.8881 &data=depth&units=english&series=pds 1 /4

8/24/22, 11:00 AM
Precipitation Frequency Data Server
NOAA Atlas 14, Volume 2, Version 3
Location name: Cary, North Carolina, USA* ""�'°
Latitude: 35.784*, Longitude:-78.8881*
Elevation: 332.52 ft**
*source: ESRI Maps 'w,�w, �d
source: USGS
POINT PRECIPITATION FREQUENCY ESTIMATES
G.M. Bonnin, D. Martin, B. Lin, T. Parzybok, M.Yekta, and D. Riley
NOAA, National Weather Service, Silver Spring, Maryland
PF tabular I PF graphical I Maps & aerials
PF tabular
PDS-based point precipitation frequency estimates with 90% confidence intervals (in inches/hourp
Duration
Average recurrence interval (years)
1
2
5
10
25
50
1 100
100
200
500
1000
4.84
5.66
6.49
7.20
7.93
8.46
8.94
9.34
9.78
10.1
5-min
(4.43-5.28)
(5.18-6.18)
(5.95-7.09)
(6.59-7.85)
(7.24-8.64)
(7.68-9.22)
(8.06-9.73)
(8.39-10.2)
(8.70-10.7)
(8.94-11.1)
3.86
4.52
5.20
5.76
6.32
6.74
7.10
7.40
7.73
7.97
10-min
(3.54-4.21)
(4.15-4.94)
(4.77-5.68)
(5.27-6.28)
(5.76-6.89)
(6.12-7.34)
(6.41-7.73)
(6.65-8.07)
(6.88-8.43)
(7.04-8.71)
3.22
3.79
4.38
4.86
5.34
5.69
5.98
6.23
6.49
6.67
15-min
(2.95-3.51)1
(3.48-4.14) 11
(4.02-4.78) 11
(4.44-5.30) 11
(4.87-5.82)
1 (5.16-6.20)
1 (5.40-6.51)
1 (5.59-6.79)
1 (5.78-7.07)
1 (5.89-7.28)
2.21
2.62
3.11
3.52
3.96
4.28
4.58
4.85
5.16
5.40
30-min
(2.02-2.41)
(2.40-2.86)
(2.86-3.40)
(3.22-3.84)
(3.61-4.31)
(3.89-4.67)
(4.14-4.99)
(4.35-5.28)
(4.59-5.63)
(4.77-5.90)
1.38
1.64
2.00
2.29
2.63
2.90
3.16
3.40
3.70
3.94
60-min
(1.26-1.50) 11
(1.51-1.80) 11
(1.83-2.18) 11
(2.10-2.50)
(2.40-2.87)
(2.64-3.16)
(2.85-3.44)
(3.05-3.71)
(3.30-4.04)
(3.48-4.31)
0.800
0.958
1.18
1.36
1.59
1.77
1.95
2.12
2.35
2.53
2-hr
(0.730-0.880)
(0.875-1.05) 11
(1.07-1.30) 11
(1.24-1.50) 11
(1.43-1.74)
1 (1.59-1.94)
1 (1.74-2.13)
1 (1.88-2.32)
(2.06-2.57)
(2.21-2.78)
0.565
0.678
0.835
0.973
1.15
1.29
1.43
1.58
1.77
1.93
3-hr
(0.517-0.621)
(0.620-0.745)
(0.763-0.919)
(0.885-1.07)
(1.04-1.25)
1 (1.16-1.41)
1 (1.28-1.57)
1 (1.40-1.72)
1 (1.55-1.94)
1 (1.68-2.12)
0.341
0.409
0.505
0.589
0.696
0.787
0.877
0.971
1.10
1.20
6-hr
(0.314-0.374)
(0.376-0.448)
(0.463-0.553)
(0.538-0.643)
(0.632-0.758)
(0.710-0.856)
(0.785-0.954)
(0.860-1.06)
(0.959-1.19)
1 (1.04-1.31)
0.201
0.241
0.298
0.350
0.417
0.474
0.532
0.594
0.678
0.750
12-hr
(0.185-0.219)
(0.222-0.263)
(0.274-0.326)
(0.320-0.381)
(0.378-0.453)
(0.427-0.513)
(0.475-0.576)
(0.524-0.641)
(0.588-0.732)
(0.641-0.811)
0.119
0.144
0.180
0.209
0.247
0.278
0.309
0.341
0.384
0.418
24-hr
(0.111-0.128)
(0.135-0.155)
(0.168-0.193)
(0.195-0.224)
(0.230-0.265)
(0.257-0.298)
(0.285-0.331)
(0.314-0.366)
(0.352-0.413)
(0.382-0.451)
0.069
0.083
0.103
0.119
0.140
0.156
0.173
0.190
0.213
0.231
2-day
(0.064-0.074)
(0.077-0.089)
(0.096-0.111)
(0.110-0.127)
(0.130-0.150)
(0.144-0.168)
(0.160-0.186)
(0.175-0.205)
(0.195-0.230)
(0.211-0.250)
0.049
0.058
0.072
0.083
0.097
0.109
0.121
0.132
0.149
0.161
3-day
(0.045-0.052)
(0.054-0.063)
(0.067-0.077)
(0.077-0.089)
(0.090-0.105)
(0.101-0.117)
(0.111-0.130)
(0.122-0.142)
(0.136-0.160)
(0.147-0.174)
0.038
0.046
0.057
0.065
0.076
0.085
0.094
0.104
0.116
0.126
4-day
(0.036-0.041)
(0.043-0.049)
(0.053-0.061)
(0.061-0.070)
(0.071-0.082)
(0.079-0.091)
(0.087-0.101)
(0.095-0.111)
(0.107-0.125)
(0.115-0.136)
0.025
0.030
0.037
0.042
0.049
0.054
0.060
0.066
0.074
0.080
7-day
(0.024-0.027)
(0.028-0.032)
(0.034-0.039)
(0.039-0.045)
(0.046-0.052)
(0.051-0.058)
(0.056-0.064)
(0.061-0.070)
(0.068-0.079)
(0.073-0.086)
0.020
0.024
0.029
0.033
0.038
0.042
0.046
0.050
0.055
0.059
10-day
(0.019-0.022)
(0.023-0.026)
(0.027-0.031)
(0.031-0.035)
(0.035-0.040)
(0.039-0.044)
(0.042-0.049)
(0.046-0.053)
(0.051-0.059)
(0.055-0.064)
0.013
0.016
0.019
0.021
0.024
0.027
0.029
0.031
0.035
0.037
20-day
(0.013-0.014)
(0.015-0.017)
(0.018-0.020)
(0.020-0.022)
(0.023-0.026)
(0.025-0.028)
(0.027-0.031)
(0.029-0.034)
(0.032-0.037)
(0.034-0.040)
0.011
0.013
0.015
0.017
0.019
0.021
0.022
0.024
0.026
0.028
30-day
(0.010-0.012)
(0.012-0.014)
(0.014-0.016)
(0.016-0.018)
(0.018-0.020)
(0.019-0.022)
(0.021-0.024)
(0.022-0.026)
(0.024-0.028)
(0.026-0.030)
0.009
0.011
0.013
0.014
0.016
0.017
0.018
0.019
0.021
0.022
45-day
(0.009-0.010)
(0.011-0.012)
(0.012-0.013)
(0.013-0.015)
(0.015-0.016)
(0.016-0.018)
(0.017-0.019)
(0.018-0.020)
(0.019-0.022)
(0.020-0.023)
0.009
0.010
0.011
0.012
0.013
0.014
0.015
0.016
0.017
0.018
60-day
(0.008-0.009)
(0.009-0.010)
(0.011-0.012)
(0.012-0.013)
(0.013-0.014)
(0.014-0.015)
(0.015-0.016)
(0.015-0.017)
(0.016-0.018)
(0.017-0.019)
Precipitation frequency (PF) estimates in this table are based on frequency analysis of partial duration series (PDS).
Numbers in parenthesis are PF estimates at lower and upper bounds of the 90% confidence interval. The probability that precipitation frequency estimates (for a
given duration and average recurrence interval) will be greater than the upper bound (or less than the lower bound) is 5%. Estimates at upper bounds are not
checked against probable maximum precipitation (PMP) estimates and may be higher than currently valid PMP values.
Please refer to NOAA Atlas 14 document for more information.
Back to Top
PF graphical
https://hdsc.nws.noaa.gov/hdsc/pfds/pfds_printpage.html?Iat=35.7840&Ion=-78.8881 &data=intensity&units=english&series=pds 1 /4