SW6180602_Calculations_20180706

CIVIL CALCULATIONS
DUKE ENERGY PROGRESS
LINDEN 230Kv SUBSTATION

The civil calculations attached are for the storm water management and erosion
and sediment control analysis.

100% Submittal (Revised): 6 July 2018

Prepared by:

Stantec Consulting Services Inc.

801 Jones Franklin Road, Suite 300
Raleigh, North Carolina, 27606
[phone] //Fax [phone]

TABLE OF CONTENTS

Stormwater Management Project Narrative……………………………………………….p.1
Soils Map…………………………………………………………………………………………………….p.3
Soils Map – Hydrologic Groups…………………………………………………………..……….p.6
Storm Drain and Riprap Outlet Calculations…………………………………………….....p.10
Permanent Stone Ditch Calculations……………………………………………………………p.19
C Coefficient and Discharge Calculations for Permanent Ditches and Storm
Drainage System………………….………………..…………………………….……………………..p.21
Page 1

Duke Energy Progress, Linden 230kV Substation
Stormwater Management Narrative
The proposed project known as Duke Energy Progress, Linden 230kV Substation
consists of a new gravel substation yard and a new gravel access drive. This report
presents the stormwater management and erosion and sediment control calculations
for the project.
The property is located in Harnett County, Erwin, North Carolina with direct access to
the site off of Horseshoe Bend Road (SR 2027). The undeveloped site is situated
south of Horseshoe Bend Road. The site is bordered by agriculture land along the
majority of the property with Horseshoe Bend Road to the north. An existing grassed
Duke Energy 90-foot right-of-way parallels the eastern property line and runs north-
south.
The site topography is very flat. Flow from the project site flows into Little River
(Stream Index 18-23-(24)) (C) which is approximately 1,600 feet away and ultimately
flows to Cape Fear River (Cape Fear River Basin) which is approximately 5 miles away
from the project site. The property is not located in a water supply watershed. The
contractor will be working closely will Duke Energy Progress which will conduct various
inspections and oversee the general construction of the project. The scope of work for
the Linden 230kV Substation project includes electrical and civil site work.
The project site is located on an undeveloped site primarily consisting of existing
agriculture land with some areas of woods. The proposed site will disturb greater than
1.0 acre. Per the stormwater interactive map and in consulting with NCDEQ
Fayetteville Regional office, the project is subject to the Phase II Post-Construction
stormwater management rules and will require a State of North Carolina Stormwater
permit. The stormwater management rules based upon the surface water
classification and watershed for the project site allow a maximum of 24% impervious
area limits for a low-density development, which does not require stormwater
management treatment measures. For the impervious area calculations, the proposed
ABC stone is considered as impervious and the proposed #57 stone is considered
pervious. The #57 stone will only be located inside/immediately adjacent the proposed
fenced/energized substation equipment yard. The designation of #57 stone for inside
substations as pervious follows the recent NCDEQ guidelines/clarifications for
substations. The site’s new, future, and existing built upon area equals approximately
6.70% impervious and therefore, is considered low-density and will not require
stormwater management treatment. Runoff from the project site will be conveyed by
vegetative conveyance measures of sheet flow to existing grass areas and stone
ditches underlaid with a 6-inch depth of sand where topography dictates. Stone
ditches with 6-inch depth of sand layer are being provided in lieu of grass ditches
because the longitudinal slope is very flat and providing the stone and sand will help to
minimize standing water by providing an area for the stormwater to infiltrate into the
soils. The use of the stone ditches will help the maintenance staff access and mow
grass areas on the other side of the stone ditches. Storm drain culvert pipes are being
Page 2

provided where required to convey the stormwater underneath roads. In the proposed
development conditions, the proposed stone ditches will have maximum side slopes of
4:1 and will provide conveyance of the stormwater within acceptable velocity limits for
the 10-year storm event. Shear stress/velocity calculations confirm the proposed
stone ditches are sufficiently protected to handle the post-construction flow without
eroding and for the stone material from being displaced.
This project will consist of approximately 49,500 sf new impervious area, approximately
2,000 sf of future impervious area, and approximately 500 sf of existing impervious
area for a total permitted impervious area of approximately 52,000 sf of impervious
area which equals 6.70% impervious area for the property. Drainage areas were
delineated from field prepared topographic survey. Post development impervious
areas were based on the proposed site plan. Hydrological soil groups were obtained
from USDA Soil Survey as published on the USDA NRCS soil survey website. The soil
types onsite are Altavista fine sandy loam (AtA) and State fine sandy loam (StA) of the
hydrologic group “C” and “B” respectively. A geotechnical engineer performed seven
borings for the purpose of determining recommended pavement design as well as to
aid in the project construction. The 2-, 10- and 25-year precipitation intensities were
taken from NOAA’s website for the specific project area.
Soil Map—Harnett County, North Carolina
(Linden 230kV)
Natural Resources
Conservation Service
Web Soil Survey
National Cooperative Soil Survey
2/12/2018
Page 1 of 33904700390477039048403904910390498039050503905120390477039048403904910390498039050503905120703130703200703270703340703410703480703550703620703690703760
703130 703200 703270 703340 703410 703480 703550 703620 703690 703760
35° 16' 7'' N 78° 46' 1'' W35° 16' 7'' N78° 45' 35'' W35° 15' 53'' N
78° 46' 1'' W35° 15' 53'' N
78° 45' 35'' WN
Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 17N WGS84
0 100 200 400 600
Feet
0 40 80 160 240
Meters
Map Scale: 1:3,000 if printed on A landscape (11" x 8.5") sheet.
Soil Map may not be valid at this scale.
Page 3
MAP LEGEND MAP INFORMATION
Area of Interest (AOI)
Area of Interest (AOI)
Soils
Soil Map Unit Polygons
Soil Map Unit Lines
Soil Map Unit Points
Special Point Features
Blowout
Borrow Pit
Clay Spot
Closed Depression
Gravel Pit
Gravelly Spot
Landfill
Lava Flow
Marsh or swamp
Mine or Quarry
Miscellaneous Water
Perennial Water
Rock Outcrop
Saline Spot
Sandy Spot
Severely Eroded Spot
Sinkhole
Slide or Slip
Sodic Spot
Spoil Area
Stony Spot
Very Stony Spot
Wet Spot
Other
Special Line Features
Water Features
Streams and Canals
Transportation
Rails
Interstate Highways
US Routes
Major Roads
Local Roads
Background
Aerial Photography
The soil surveys that comprise your AOI were mapped at
1:24,000.
Warning: Soil Map may not be valid at this scale.
Enlargement of maps beyond the scale of mapping can cause
misunderstanding of the detail of mapping and accuracy of soil
line placement. The maps do not show the small areas of
contrasting soils that could have been shown at a more detailed
scale.
Please rely on the bar scale on each map sheet for map
measurements.
Source of Map: Natural Resources Conservation Service
Web Soil Survey URL:
Coordinate System: Web Mercator (EPSG:3857)
Maps from the Web Soil Survey are based on the Web Mercator
projection, which preserves direction and shape but distorts
distance and area. A projection that preserves area, such as the
Albers equal-area conic projection, should be used if more
accurate calculations of distance or area are required.
This product is generated from the USDA-NRCS certified data as
of the version date(s) listed below.
Soil Survey Area: Harnett County, North Carolina
Survey Area Data: Version 14, Sep 26, 2017
Soil map units are labeled (as space allows) for map scales
1:50,000 or larger.
Date(s) aerial images were photographed: Aug 13, 2014—Feb
4, 2017
The orthophoto or other base map on which the soil lines were
compiled and digitized probably differs from the background
imagery displayed on these maps. As a result, some minor
shifting of map unit boundaries may be evident.
Soil Map—Harnett County, North Carolina
(Linden 230kV)
Natural Resources
Conservation Service
Web Soil Survey
National Cooperative Soil Survey
2/12/2018
Page 2 of 3
Page 4
Map Unit Legend
Map Unit Symbol Map Unit Name Acres in AOI Percent of AOI
AnB Alpin sand, 0 to 6 percent
slopes, Southern Coastal
Plain
6.8 20.5%
AtA Altavista fine sandy loam, 0 to
3 percent slopes, rarely
flooded, Southern Coastal
Plain
10.6 31.7%
StA State fine sandy loam, 0 to 3
percent slopes, rarely
flooded
14.4 43.2%
WkD Wickham fine sandy loam, 6 to
15 percent slopes, rarely
flooded
1.5 4.6%
Totals for Area of Interest 33.4 100.0%
Soil Map—Harnett County, North Carolina Linden 230kV
Natural Resources
Conservation Service
Web Soil Survey
National Cooperative Soil Survey
2/12/2018
Page 3 of 3Page 5
Hydrologic Soil Group—Harnett County, North Carolina
(Linden 230kV)
Natural Resources
Conservation Service
Web Soil Survey
National Cooperative Soil Survey
2/12/2018
Page 1 of 43904700390477039048403904910390498039050503905120390477039048403904910390498039050503905120703130703200703270703340703410703480703550703620703690703760
703130 703200 703270 703340 703410 703480 703550 703620 703690 703760
35° 16' 7'' N 78° 46' 1'' W35° 16' 7'' N78° 45' 35'' W35° 15' 53'' N
78° 46' 1'' W35° 15' 53'' N
78° 45' 35'' WN
Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 17N WGS84
0 100 200 400 600
Feet
0 40 80 160 240
Meters
Map Scale: 1:3,000 if printed on A landscape (11" x 8.5") sheet.
Soil Map may not be valid at this scale.
Page 6
MAP LEGEND MAP INFORMATION
Area of Interest (AOI)
Area of Interest (AOI)
Soils
Soil Rating Polygons
A
A/D
B
B/D
C
C/D
D
Not rated or not available
Soil Rating Lines
A
A/D
B
B/D
C
C/D
D
Not rated or not available
Soil Rating Points
A
A/D
B
B/D
C
C/D
D
Not rated or not available
Water Features
Streams and Canals
Transportation
Rails
Interstate Highways
US Routes
Major Roads
Local Roads
Background
Aerial Photography
The soil surveys that comprise your AOI were mapped at
1:24,000.
Warning: Soil Map may not be valid at this scale.
Enlargement of maps beyond the scale of mapping can cause
misunderstanding of the detail of mapping and accuracy of soil
line placement. The maps do not show the small areas of
contrasting soils that could have been shown at a more detailed
scale.
Please rely on the bar scale on each map sheet for map
measurements.
Source of Map: Natural Resources Conservation Service
Web Soil Survey URL:
Coordinate System: Web Mercator (EPSG:3857)
Maps from the Web Soil Survey are based on the Web Mercator
projection, which preserves direction and shape but distorts
distance and area. A projection that preserves area, such as the
Albers equal-area conic projection, should be used if more
accurate calculations of distance or area are required.
This product is generated from the USDA-NRCS certified data as
of the version date(s) listed below.
Soil Survey Area: Harnett County, North Carolina
Survey Area Data: Version 14, Sep 26, 2017
Soil map units are labeled (as space allows) for map scales
1:50,000 or larger.
Date(s) aerial images were photographed: Aug 13, 2014—Feb
4, 2017
The orthophoto or other base map on which the soil lines were
compiled and digitized probably differs from the background
imagery displayed on these maps. As a result, some minor
shifting of map unit boundaries may be evident.
Hydrologic Soil Group—Harnett County, North Carolina
(Linden 230kV)
Natural Resources
Conservation Service
Web Soil Survey
National Cooperative Soil Survey
2/12/2018
Page 2 of 4
Page 7
Hydrologic Soil Group
Map unit symbol Map unit name Rating Acres in AOI Percent of AOI
AnB Alpin sand, 0 to 6
percent slopes,
Southern Coastal
Plain
A 6.8 20.5%
AtA Altavista fine sandy
loam, 0 to 3 percent
slopes, rarely flooded,
Southern Coastal
Plain
C 10.6 31.7%
StA State fine sandy loam, 0
to 3 percent slopes,
rarely flooded
B 14.4 43.2%
WkD Wickham fine sandy
loam, 6 to 15 percent
slopes, rarely flooded
B 1.5 4.6%
Totals for Area of Interest 33.4 100.0%
Hydrologic Soil Group—Harnett County, North Carolina Linden 230kV
Natural Resources
Conservation Service
Web Soil Survey
National Cooperative Soil Survey
2/12/2018
Page 3 of 4Page 8
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
Hydrologic Soil Group—Harnett County, North Carolina Linden 230kV
Natural Resources
Conservation Service
Web Soil Survey
National Cooperative Soil Survey
2/12/2018
Page 4 of 4Page 9
STORM DRAINAGE SCHEDULE
Linden 230kV
7/5/2018 4:25 PM
Designed By:JSS Project #:Linden 230kV
Checked By:JSS Date:5-Jul-18
Tc Tc I10/I25 I10/I25 Cc Q25 Q25 Q10/Q25 Actual Upstream Downstream Upstream Structure
From To Inlet Total Inlet Pipe Pipe Pipe Inlet Composite Side-Cumulative Total Slope Calculated Pipe Actual Velocity Length Segment Invert Invert Pipe EP/Rim Minimum Minimum
(upstream)Area Area Time of ConcTravel TimeTime of Conc Intensity Intensity Runoff Stream Side-StreamDischarge Diameter Diameter Velocity Full Time (From)(To)Material Elevation Depth Cover
(Acres)(Acres)(Min)(Min)(Min)(In/Hr)(In/Hr)Coefficient (cfs)(cfs)(cfs)(Ft/Ft)(In)(In)(fps)(fps)(Ft)(Min)(Ft)(Ft)(Ft)(Ft)(FT)
Culvert P-1 0.06 0.06 5.00 0.00 5.00 8.81 8.81 0.41 0.00 0.22 0.0050 4.63 15 1.80 4.0 72.00 0.67 113.15 112.79 CLASS IV RCP 115.70 2.55 1.11
Culvert P-2 1.40 1.40 5.00 0.00 5.00 8.81 8.81 0.34 0.00 4.22 0.0036 15.01 24 4.02 4.7 55.00 0.23 113.25 113.05 CLASS IV RCP 116.90 3.65 1.40
Culvert P-3 5.83 5.83 5.00 0.00 5.00 8.81 8.81 0.34 0.00 17.46 0.0026 27.18 30 5.08 4.6 46.00 0.15 112.72 112.60 CLASS IV RCP 116.50 3.78 0.99
Oil Spill Line 0.06 0.06 5.00 0.00 5.00 7.91 7.91 0.95 0.00 0.45 0.0050 5.70 6 2.49 2.2 0.00 PVC
Trench Drain Line 0.02 0.02 5.00 0.00 5.00 7.91 7.91 0.95 0.00 0.15 0.0050 3.77 4 1.91 1.7 0.00 PVC
Notes:Design for the 10-year and 25-year storm assumes the Time of CB - Catch Basin
Concentration to an individual Inlet = 5 minutes.CI - Curb Inlet
DCI - Double Curb Inlet
Actual Velocity is calculated based upon percentage DDI - Double Drop Inlet
of Full-Flowing pipe and actual depth of flow from DI - Drop Inlet
Hydraulic elements.DIS - Drop Inlet, Slab top
RCP CMP PVC HDPE EX DI - Existing Drop Inlet
Manning's "n" Factor= 0.012 0.024 0.01 0.012 JB - Junction Box
Runoff Coefficients MH - Manhole
for Rational Method: C = 0.30 (grass), C = 0.95 (pavt.), C=0.50 (single family>20,000 sf)S - Detention Structure
EW - End Wall
Notes:FES - Flared End Section
DS - Downspout
ES - End Section
(down
strea
StormDrain Calcs_linden.xls Page 10
Culvert Design Report
P-2, 24"
Title: Linden 230kV
v:\...\civil\engineering\calculations\project1.cvm
07/05/18 04:08:35 PM
STN_USA
© Bentley Systems, Inc. Haestad Methods Solution Center Watertown, CT 06795 USA [phone]
Project Engineer: jsesler
CulvertMaster v3.3 [03.03.00.04]
Page 1
Peak Discharge Method: User-Specified
Design Discharge 4.22 cfs Check Discharge 4.22 cfs
Grades Model: Inverts
Invert Upstream 113.25 ft Invert Downstream 113.05 ft
Length 55.00 ft Slope 0.003636 ft/ft
Drop 0.20 ft
Headwater Model: Unspecified
Tailwater properties: Trapezoidal Channel
Tailwater conditions for Design Storm.
Discharge 4.22 cfs Bottom Elevation 114.05 ft
Depth 0.75 ft Velocity 0.77 ft/s
Tailwater conditions for Check Storm.
Discharge 4.22 cfs Bottom Elevation 114.05 ft
Depth 0.75 ft Velocity 0.77 ft/s
Name Description Discharge HW Elev. Velocity
x Trial-1 1-24 inch Circular 4.22 cfs 114.86 ft 1.45 ft/s
Page 11
Pipe invert elevations reflect storm drain pipe buried 1'
depth below ditch elevation to allow conveyance of
stormwater runoff that reaches sand layer in stone ditch
section. Downstream ditch elevation = 114.05'
Culvert Design Report
P-2, 24"
Title: Linden 230kV
v:\...\civil\engineering\calculations\project1.cvm
07/05/18 04:08:35 PM
STN_USA
© Bentley Systems, Inc. Haestad Methods Solution Center Watertown, CT 06795 USA [phone]
Project Engineer: jsesler
CulvertMaster v3.3 [03.03.00.04]
Page 2
Design:Trial-1
Solve For: Headwater Elevation
Culvert Summary
Allowable HW Elevation N/A ft Storm Event Design
Computed Headwater Elevation 114.86 ft Discharge 4.22 cfs
Headwater Depth/Height 0.80 Tailwater Elevation 114.80 ft
Inlet Control HW Elev. 114.80 ft Control Type Outlet Control
Outlet Control HW Elev. 114.86 ft
Grades
Upstream Invert 113.25 ft Downstream Invert 113.05 ft
Length 55.00 ft Constructed Slope 0.003636 ft/ft
Hydraulic Profile
Profile M1 Depth, Downstream 1.75 ft
Slope Type Mild Normal Depth 0.76 ft
Flow Regime Subcritical Critical Depth 0.72 ft
Velocity Downstream 1.45 ft/s Critical Slope 0.004499 ft/ft
Section
Section Shape Circular Mannings Coefficient 0.013
Section Material Concrete Span 2.00 ft
Section Size 24 inch Rise 2.00 ft
Number Sections 1
Outlet Control Properties
Outlet Control HW Elev. 114.86 ft Upstream Velocity Head 0.04 ft
Ke 0.20 Entrance Loss 0.01 ft
Inlet Control Properties
Inlet Control HW Elev. 114.80 ft Flow Control Unsubmerged
Inlet Type Groove end projecting Area Full 3.1 ft²
K 0.00450 HDS 5 Chart 1
M 2.00000 HDS 5 Scale 3
C 0.03170 Equation Form 1
Y 0.69000
Page 12
Culvert Design Report
P-3, 30"
Title: Linden 230kV
v:\...\civil\engineering\calculations\project1.cvm
07/05/18 04:15:39 PM
STN_USA
© Bentley Systems, Inc. Haestad Methods Solution Center Watertown, CT 06795 USA [phone]
Project Engineer: jsesler
CulvertMaster v3.3 [03.03.00.04]
Page 1
Peak Discharge Method: User-Specified
Design Discharge 17.47 cfs Check Discharge 17.47 cfs
Grades Model: Inverts
Invert Upstream 112.72 ft Invert Downstream 112.60 ft
Length 46.00 ft Slope 0.002609 ft/ft
Drop 0.12 ft
Headwater Model: Unspecified
Tailwater properties: Trapezoidal Channel
Tailwater conditions for Design Storm.
Discharge 17.47 cfs Bottom Elevation 113.60 ft
Depth 1.52 ft Velocity 1.15 ft/s
Tailwater conditions for Check Storm.
Discharge 17.47 cfs Bottom Elevation 113.60 ft
Depth 1.52 ft Velocity 1.15 ft/s
Name Description Discharge HW Elev. Velocity
x Trial-1 1-30 inch Circular 17.47 cfs 115.43 ft 3.56 ft/s
Page 13
Pipe invert elevations reflect storm drain pipe buried 1'
depth below ditch elevation to allow conveyance of
stormwater runoff that reaches sand layer in stone ditch
section. Downstream ditch elevation = 113.60'
Culvert Design Report
P-3, 30"
Title: Linden 230kV
v:\...\civil\engineering\calculations\project1.cvm
07/05/18 04:15:39 PM
STN_USA
© Bentley Systems, Inc. Haestad Methods Solution Center Watertown, CT 06795 USA [phone]
Project Engineer: jsesler
CulvertMaster v3.3 [03.03.00.04]
Page 2
Design:Trial-1
Solve For: Headwater Elevation
Culvert Summary
Allowable HW Elevation N/A ft Storm Event Design
Computed Headwater Elevation 115.43 ft Discharge 17.47 cfs
Headwater Depth/Height 1.09 Tailwater Elevation 115.12 ft
Inlet Control HW Elev. 115.12 ft Control Type Outlet Control
Outlet Control HW Elev. 115.43 ft
Grades
Upstream Invert 112.72 ft Downstream Invert 112.60 ft
Length 46.00 ft Constructed Slope 0.002609 ft/ft
Hydraulic Profile
Profile CompositePressureProfileM1 Depth, Downstream 2.52 ft
Slope Type N/A Normal Depth 1.74 ft
Flow Regime Subcritical Critical Depth 1.41 ft
Velocity Downstream 3.56 ft/s Critical Slope 0.004829 ft/ft
Section
Section Shape Circular Mannings Coefficient 0.013
Section Material Concrete Span 2.50 ft
Section Size 30 inch Rise 2.50 ft
Number Sections 1
Outlet Control Properties
Outlet Control HW Elev. 115.43 ft Upstream Velocity Head 0.20 ft
Ke 0.20 Entrance Loss 0.04 ft
Inlet Control Properties
Inlet Control HW Elev. 115.12 ft Flow Control Unsubmerged
Inlet Type Groove end projecting Area Full 4.9 ft²
K 0.00450 HDS 5 Chart 1
M 2.00000 HDS 5 Scale 3
C 0.03170 Equation Form 1
Y 0.69000
Page 14
Outlet:Project No.:Linden 230kV
Designed by:JSS
Checked by:
Date:17-May-18
d (chart) = depth in pipe
Q = 0.45 cfs dmax = 1.5*(d50)
V = 2.49 fps Do = Pipe Diameter
Do = 0.50 ft 6 in W = Do + La
La = 6 ft (Using 10', >required)H = minimum height of rip rap channel
W =6.50 ft
d50 (chart)= 0.20 ft 2.4 in Use Class B RipRap d50=8 in
dmax = 1.00 ft 12 in
H =1.00 ft 12.00 in
4" & 6" SUBSTATION
OUTLETS
Riprap_Protection.xls Page 15
Outlet:P-1 15 " OUTLET Project No.:Linden 230kV
Designed by:JSS
Checked by:
Date:20-Mar-18
d (chart) = depth in pipe
Q = 0.22 cfs dmax = 1.5*(d50)
V = 1.8 fps Do = Pipe Diameter
Do = 1.25 ft 15 in W = Do + La
La = 10 ft (Using 10'>required)H = minimum height of rip rap channel
W =11.25 ft
d50 (chart)= 0.20 ft 2.4 in Use Class B RipRap d50=8 in
dmax = 1.00 ft 12 in
H =1.00 ft 12.00 in
Riprap_Protection.xls Page 16
Outlet:P-2 24 " OUTLET Project No.:Linden 230kV
Designed by:JSS
Checked by:
Date:05-Jul-18
d (chart) = depth in pipe
Q = 4.22 cfs dmax = 1.5*(d50)
V = 4.02 fps Do = Pipe Diameter
Do = 2.00 ft 24 in W = Do + La
La = 10 ft (Using 10'>required)H = minimum height of rip rap channel
W =12.00 ft
d50 (chart)= 0.20 ft 2.4 in Use Class B RipRap d50=8 in
dmax = 1.00 ft 12 in
H =1.00 ft 12.00 in
Riprap_Protection.xls Page 17
Outlet:P-3 30 " OUTLET Project No.:Linden 230kV
Designed by:JSS
Checked by:
Date:05-Jul-18
d (chart) = depth in pipe
Q = 17.47 cfs dmax = 1.5*(d50)
V = 5.08 fps Do = Pipe Diameter
Do = 2.50 ft 30 in W = Do + La
La = 14 ft H = minimum height of rip rap channel
W =16.50 ft
d50 (chart)= 0.40 ft 4.8 in Use Class B RipRap d50=8 in
dmax = 1.00 ft 12 in
H =1.00 ft 12.00 in
Riprap_Protection.xls Page 18
Project Description
Friction Method Manning Formula
Solve For Normal Depth
Input Data
Roughness Coefficient 0.033
Channel Slope 0.00200 ft/ft
Left Side Slope 4.00 ft/ft (H:V)
Right Side Slope 4.00 ft/ft (H:V)
Bottom Width 4.00 ft
Discharge 19.49 ft³/s
Results
Normal Depth 1.26 ft
Flow Area 11.33 ft²
Wetted Perimeter 14.36 ft
Hydraulic Radius 0.79 ft
Top Width 14.05 ft
Critical Depth 0.71 ft
Critical Slope 0.02046 ft/ft
Velocity 1.72 ft/s
Velocity Head 0.05 ft
Specific Energy 1.30 ft
Froude Number 0.34
Flow Type Subcritical
GVF Input Data
Downstream Depth 0.00 ft
Length 0.00 ft
Number Of Steps 0
GVF Output Data
Upstream Depth 0.00 ft
Profile Description
Profile Headloss 0.00 ft
Downstream Velocity Infinity ft/s
Upstream Velocity Infinity ft/s
Normal Depth 1.26 ft
Critical Depth 0.71 ft
Channel Slope 0.00200 ft/ft
Critical Slope 0.02046 ft/ft
Worksheet for D#3 Phase I
7/5/2018 12:58:55 PM
Bentley Systems, Inc. Haestad Methods Solution CenterBentley FlowMaster V8i (SELECTseries 1) [08.11.01.03]
27 Siemons Company Drive Suite 200 W Watertown, CT 06795 USA [phone]of1Page
Page 19
#4 Stone (Gravel Riprap,
d50 = 1")
Manning's N from figure
8.05f Erosion and Sediment
Control Manual
10-year Q
Calculated Shear Stress
0.16 = 62.4*1.26*0.002
Ok, Allowed Shear Stress
from table 8.05g (Gravel
Riprap d50 = 1" = 0.33)
D#3 worst case scenario for ditch calculations. During construction
substation ABC stone subgrade considered impervious area (refer to
discharge calculations for more detailed explanation)
Project Description
Friction Method Manning Formula
Solve For Normal Depth
Input Data
Roughness Coefficient 0.033
Channel Slope 0.00200 ft/ft
Left Side Slope 4.00 ft/ft (H:V)
Right Side Slope 4.00 ft/ft (H:V)
Bottom Width 4.00 ft
Discharge 15.69 ft³/s
Results
Normal Depth 1.13 ft
Flow Area 9.66 ft²
Wetted Perimeter 13.34 ft
Hydraulic Radius 0.72 ft
Top Width 13.06 ft
Critical Depth 0.63 ft
Critical Slope 0.02112 ft/ft
Velocity 1.62 ft/s
Velocity Head 0.04 ft
Specific Energy 1.17 ft
Froude Number 0.33
Flow Type Subcritical
GVF Input Data
Downstream Depth 0.00 ft
Length 0.00 ft
Number Of Steps 0
GVF Output Data
Upstream Depth 0.00 ft
Profile Description
Profile Headloss 0.00 ft
Downstream Velocity Infinity ft/s
Upstream Velocity Infinity ft/s
Normal Depth 1.13 ft
Critical Depth 0.63 ft
Channel Slope 0.00200 ft/ft
Critical Slope 0.02112 ft/ft
Worksheet for D#3
7/5/2018 12:57:04 PM
Bentley Systems, Inc. Haestad Methods Solution CenterBentley FlowMaster V8i (SELECTseries 1) [08.11.01.03]
27 Siemons Company Drive Suite 200 W Watertown, CT 06795 USA [phone]of1Page
Page 20
#4 Stone (Gravel Riprap,
d50 = 1")
Manning's N from figure
8.05f Erosion and Sediment
Control Manual
10-year Q
Calculated Shear Stress
0.14 = 62.4*1.13*0.002
Ok, Allowed Shear Stress
from table 8.05g (Gravel
Riprap d50 = 1" = 0.33)
D#3 worst case scenario for ditch calculations. Final conditions, after
construction, substation #57 stone considered pervious area (refer to
discharge calculations for more detailed explanation)
Culvert P-1
DA 0.06 (Ac)
C Coef.
0.01 Impervious (Ac)0.95
0.00 Woods (Ac)0.25
0.05 Grass (Ac)0.30
C=0.408
I 2year=6.16 I 10year=7.91 I 25year=8.81
Q(2) DA=0.15 Q(10) DA=0.19 Q(25) DA=0.22
Culvert P-2
DA 1.4 (Ac)
C Coef.
0.09 Impervious (Ac)0.95
0.00 Woods (Ac)0.25
1.31 Grass (Ac)0.30
C=0.342
I 10year=7.91 I 25year=8.81
Q(10) DA=3.78 Q(25) DA=4.22
Culvert P-3
DA 5.83 (Ac)
C Coef.
0.36 Impervious (Ac)0.95
0.00 Woods (Ac)0.25
5.47 Grass (Ac)0.30
C=0.340
I 10year=7.91 I 25year=8.81
Q(10) DA=15.69 Q(25) DA=17.47
Stone Ditch (D#1)
DA 1.40 (Ac)
C Coef.
0.09 Impervious (Ac)0.95
0.00 Woods (Ac)0.25
1.31 Grass (Ac)0.30
C=0.342
I 2year=6.16 I 10year=7.91
Q(2) DA=2.95 Q(10) DA=3.78
C Coefficient and Discharge Calculations - Permanent Ditches and Storm Drainage
System
Substation yard will have 3" #57 stone on top of 3" ABC stone
after equipment is installed. #57 stone is taken as pervious
and is not counted as impervious; however, equipment
concrete foundations are counted as impervious.
Page 21
Stone Ditch (D#2)
DA 3.48 (Ac)
C Coef.
0.43 Impervious (Ac)0.95
0.00 Woods (Ac)0.25
3.05 Grass (Ac)0.30
C=0.380
I 2year=6.16 I 10year=7.91
Q(2) DA=8.15 Q(10) DA=10.47
Stone Ditch (D#3)
DA 5.83 (Ac)
C Coef.
0.36 Impervious (Ac)0.95
0.00 Woods (Ac)0.25
5.47 Grass (Ac)0.30
C=0.340
I 2year=6.16 I 10year=7.91
Q(2) DA=12.22 Q(10) DA=15.69
Stone Ditch D#2 (Phase I)
DA 3.48 (Ac)
C Coef.
1.15 Impervious (Ac)0.95
0.00 Woods (Ac)0.25
2.33 Grass (Ac)0.30
C=0.515
I 2year=6.16 I 10year=7.91
Q(2) DA=11.04 Q(10) DA=14.17
Stone Ditch D#3 (Phase I)
DA 5.83 (Ac)
C Coef.
1.10 Impervious (Ac)0.95
0.00 Woods (Ac)0.25
4.73 Grass (Ac)0.30
C=0.423
I 2year=6.16 I 10year=7.91
Q(2) DA=15.18 Q(10) DA=19.49
Before final 6" stone placed on yard. Substation yard will have
3" ABC stone subgrade. ABC stone is taken as impervious.
Before final 6" stone placed on yard. Substation yard will have
3" ABC stone subgrade. ABC stone is taken as impervious.
Substation yard will have 3" #57 stone on top of 3" ABC stone
after equipment is installed. #57 stone is taken as pervious
and is not counted as impervious; however, equipment
concrete foundations are counted as impervious.
Substation yard will have 3" #57 stone on top of 3" ABC stone
after equipment is installed. #57 stone is taken as pervious
and is not counted as impervious; however, equipment
concrete foundations are counted as impervious.
Page 22