Attachment NEB 5.20-1 Phase II Hydrotechnical Hazards Assessment

Transcription

Energy East Pipeline Ltd.
NEB Information Request 5
Attachment NEB 5.20-1
Attachment NEB 5.20-1
Phase II Hydrotechnical Hazards Assessment
November 2015
Document Title: Energy East Conversion Along the TransCanada
Mainline Corridor, Hydrotechnical Hazards Phase II Assessment
Document Number: EE4930-GAL-C-RP-0009
Revision Number: 0
Contract Number: 4500003907
Golder Associates Ltd.
102, 2535 – 3rd Avenue S.E.
Calgary, Alberta
Canada, T2A 7Wg
(403) 299-5600
Rev
No.
Rev Date
yyyy-mm-dd
Reason for Issue
Contractor
Originator
Contractor
Reviewer
Contractor
Approver
0
2015-05-20
IFU
Jay Hatcher
Mark Nixon
Mark Nixon
Page 1 of 35
Energy East Protected
UNCONTROLLED IF PRINTED
EE4930-GAL-C-RP-0009
Energy East Conversion Along the TransCanada Mainline
Corridor, Hydrotechnical Hazards Phase II Assessment
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2015
May 2015
ENERGY EAST CONVERSION ALONG THE
TRANSCANADA MAINLINE CORRIDOR
HYDROTECHNICAL HAZARDS
PHASE II ASSESSMENT,
REVISION 0
REPORT
Submitted to:
TransCanada Corporation
450 - 1st Street. S.W.
Calgary, Alberta
Canada, T2P 5H1
Report Number: 13-1397-0008 4000 Phase II Rev. 0
Distribution:
1 Electronic Copy - TransCanada Corporation
1 Electronic Copy - Golder Associates Ltd.
EXECUTIVE SUMMARY
TransCanada Corporation (TransCanada) is currently planning to implement its Energy East Pipeline Project
(EE). The proposed pipeline consists of a 4,600 km long pipeline to run west to east across Canada from
Hardisty, Alberta, to the Bay of Fundy near Saint John, New Brunswick. The pipeline is being developed to
transport 1.1 million barrels of crude oil per day from Alberta and Saskatchewan to refineries and marine
terminals in Québec and New Brunswick. A component of the project will involve the conversion of existing
natural gas pipeline segments between Burstall Saskatchewan and the St. Lawrence River near Ottawa Ontario
(the EE Conversion pipeline) for crude oil transportation. The Western Section of the EE Conversion pipeline
from Burstall Saskatchewan to west of Starbuck Manitoba is about 800 km long, and the Central Section from
east of Starbuck Manitoba to Ottawa Ontario is approximately 2,200 km long.
TransCanada is undertaking a hydrotechnical hazard assessment of water crossings along the proposed EE
Conversion pipeline. Along the entire length of the EE Conversion, there are multiple other TransCanada natural
gas pipelines within a common corridor, known as the TransCanada Mainline Corridor.
TransCanada employs a phased approach to the assessment of hydrotechnical hazards along pipelines. Golder
Associates Ltd. (Golder) completed a preliminary Phase I assessment of the hydrotechnical hazards at water
crossings along the EE Conversion pipeline in October 2013 (updated and re-issued as Golder 2015). The
Phase I assessment provided an initial overview assessment of the pipeline alignment, an inventory of water
crossings, and a preliminary classification of hazard ratings for each crossing. The assessment was based on a
desktop review of existing information plus an aerial (helicopter) reconnaissance. The Phase I assessment
provided TransCanada with a preliminary list of 55 priority water crossings (out of 1,869 mapped water
crossings), 47 with Moderate and 8 with High hydrotechnical hazards, for further investigation. Two additional
water crossings of the Assiniboine River within this region will be re-constructed as part of the EE New Build
pipeline.
The purpose of this Phase II assessment was to further characterize the hydrotechnical hazards at priority
crossings that were initially assigned Moderate and High hazard ratings during the Phase I assessment, with the
intent to confirm/refine the preliminary hazard ratings. The Phase II assessment provided a site-specific
evaluation of the 57 water crossings, consisting of field investigations and further desktop work, to determine
additional attributes of the crossings. The list of priority crossings has subsequently been revised to a total of 36
crossings (30 Moderate and 6 High), based on the interpretation of additional information. This number
represents 2% of the total number of mapped crossings along the EE Conversion pipeline. The priority
crossings are:

Western Pipeline Section of the pipeline - 6 Moderate hazard crossings.

Central Pipeline Section of the pipeline - 24 Moderate hazard crossings and 6 High hazard crossings.
The next step for TransCanada is to proceed with further detailed engineering evaluations at high hazard
crossings. Moderate hazard crossings should be considered for ground-based monitoring.
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Table of Contents
1.0
INTRODUCTION ............................................................................................................................................................... 7
1.1
Background.......................................................................................................................................................... 7
1.2
Purpose and Scope of Assessment ..................................................................................................................... 7
1.3
Phased Approach to Hydrotechnical Hazards Assessments ............................................................................... 8
1.4
Definition of Hydrotechnical Hazards ................................................................................................................... 9
2.0
PHYSICAL SETTING........................................................................................................................................................ 9
3.0
METHODS ...................................................................................................................................................................... 10
3.1
Water Crossing Inventory .................................................................................................................................. 10
3.2
Field Investigations ............................................................................................................................................ 11
3.3
Hydrological Analysis......................................................................................................................................... 12
3.4
Hydraulic Analysis ............................................................................................................................................. 14
3.5
Bed Scour Assessment ..................................................................................................................................... 14
3.6
Pipe Design and Survey Information ................................................................................................................. 16
4.0
ASSESSMENT OF HYDROTECHNICAL HAZARDS..................................................................................................... 16
5.0
HIGH HAZARD CROSSINGS ......................................................................................................................................... 18
5.1
6.0
Central Pipeline Section .................................................................................................................................... 18
MODERATE HAZARD CROSSINGS ............................................................................................................................. 20
6.1
Western Pipeline Section ................................................................................................................................... 20
6.2
Central Pipeline Section .................................................................................................................................... 23
7.0
LOW HAZARD CROSSINGS ......................................................................................................................................... 32
8.0
RECOMMENDED NEXT STEPS .................................................................................................................................... 33
9.0
CLOSING ........................................................................................................................................................................ 33
10.0 REFERENCES ................................................................................................................................................................ 35
TABLES
Table 1: Empirical Multiplying Z Factors for use by Regime Equations (Pemberton and Lara, 1984) ...................................... 16
FIGURES
Figure 1: Moderate and High Hazard Water Crossings along the Western Pipeline Section ................................................... 18
Figure 2: Moderate and High Hazard Water Crossings along the Central Pipeline Section ..................................................... 16
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APPENDICES
APPENDIX A
Western Pipeline Section - Water Crossing Inventory (Burstall Saskatchewan to Starbuck Manitoba)
APPENDIX B
Central Pipeline Section Water Crossing Inventory (Starbuck Manitoba to Ottawa Ontario)
APPENDIX C
Western Pipeline Section Moderate and High Hazard Crossings
APPENDIX D
Central Pipeline Section Moderate and High Hazard Crossings
APPENDIX E
Glossary
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1.0
1.1
INTRODUCTION
Background
TransCanada Corporation (TransCanada) is planning to implement its Energy East Pipeline Project. The
proposed pipeline consists of a 4,600 km long pipeline running west to east across Canada from Hardisty,
Alberta, to Saint John, New Brunswick. The pipeline is being developed to transport 1.1 million barrels of crude
oil per day from Alberta and Saskatchewan to refineries and marine terminals in Québec and New Brunswick.
The Energy East Pipeline Project currently involves the following three major components:

Conversion pipeline sections, converting segments along an existing natural gas pipeline in Saskatchewan,
Manitoba and Ontario (total length approximately 3,000 km) for crude oil transportation in Manitoba and
Ontario;

New-build pipeline sections, constructing new pipeline segments in Alberta, Ontario, Québec and New
Brunswick (total length approximately 1,600 km) to connect with the converted pipeline segments; and

Associated facilities, such as pump stations and tank terminals required to move crude oil from Alberta to
Québec and New Brunswick.
The EE Conversion pipeline consists of two main segments: the Western Pipeline Section from Burstall
Saskatchewan to west of Starbuck Manitoba is about 800 km long, and the Central Pipeline Section east of
Starbuck Manitoba to Ottawa Ontario is approximately 2,200 km long.
TransCanada is undertaking a hydrotechnical hazard assessment of water crossings along the proposed Energy
East Conversion pipeline. TransCanada contracted Golder Associates Ltd. (Golder) in July 2013 to carry out a
preliminary Phase I assessment of hydrotechnical hazards at water crossings along the pipeline, for the purpose
of identifying water crossings where hydrotechnical hazards have the potential to affect the pipeline (updated
and re-issued as Golder 2015). The assessment was based on a desktop study and an aerial (helicopter)
reconnaissance. The Phase I assessment provided TransCanada with a preliminary list of 55 priority water
crossings (out of 1,869 mapped water crossings) with Moderate and High hydrotechnical hazards ratings. The
Phase I assessment recommended that a Phase II assessment be undertaken at these crossings.
This report summarizes the findings and conclusions of the Phase II assessment and provides an updated list of
High and Moderate hazard crossings with recommended next steps.
1.2
Purpose and Scope of Assessment
TransCanada contracted Golder in October 2013 to conduct a Phase II assessment of the hydrotechnical
hazards at 55 water crossings along the EE Conversion pipeline that were identified and assigned Moderate and
High hazard ratings during the Phase I assessment (Golder 2015). The purpose of the Phase II assessment
was to further characterize the hydrotechnical hazards at the crossings, based on a site-specific evaluation, to
confirm/refine the preliminary (Phase I assessment) hazard ratings and to recommend potential next steps.
TransCanada also requested that the complete crossing inventory developed as part of the Phase I assessment
(1,869 water crossings) be expanded to include additional attributes based on further desktop work to provide an
index to compare the relative sizes of the watercourses at each crossing.
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The scope of work for the Phase II assessment consisted of the following for the Moderate and High hazard
crossings:

Field investigations to collect site-specific measurements and to record site-specific information;

Hydrological analysis, including the delineation of watershed areas and the estimation of design flows
based on publicly available topographical and stream flow data;

Hydraulic analysis to evaluate the hydraulic characteristics at the crossings during the design flows for pipe
burial;

Scour assessment based on available information and standard methods for estimating channel scour
during a design flood peak;

Inspect available depth of cover surveys and alignment sheets, as provided by TransCanada, to further
screen the crossings;

Update the preliminary (Phase I assessment) hazard ratings based on the additional information listed
above;

Identify coordinates for the start and end locations where the pipe may be subject to hydrotechnical
hazards; and
 Propose next steps and further investigations for each crossing.
1.3
Phased Approach to Hydrotechnical Hazards Assessments
TransCanada uses a phased approach to hydrotechnical hazards assessments along pipelines. The phased
approach has been developed over time by TransCanada to begin with a regional-scale assessment (Phase I
assessment), and proceeding to site-specific assessments (Phase II and III assessments) as needed.
The Phase I assessment provided an initial overview assessment of the pipeline alignment, considering a range
of possible hydrotechnical hazards that could affect the pipeline, based on available information. Field
investigations are not normally conducted during a Phase I assessment. Accordingly, the identification and
classification of potential hydrotechnical hazards during a Phase I assessment are generally conservative by
necessity. The descriptions and classifications of potential hydrotechnical hazards identified during a Phase I
assessment may be revised during subsequent assessment phases as additional work is performed and
additional information is collected. The results of a Phase I assessment are used to prioritize crossings that
should be targeted for further study and to recommend the scope of work for the Phase II assessment.
A Phase II assessment includes field investigations to improve the evaluation of possible or known
hydrotechnical hazards that were identified during the Phase I assessment. Most Phase II assessments are
conducted to further evaluate High hazard crossings, and potentially to evaluate Moderate hazard crossings.
The information collected during a Phase II assessment is used to determine whether further investigations are
needed and to specify the next steps. The review of pipe burial details at the pipeline crossing, such as depth of
cover and pipeline protection (e.g., concrete coating), where available, is an important assessment component.
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A Phase III assessment may be completed in cases where additional effort is needed based on the conclusions
of the Phase II assessment. A Phase III assessment consists of a detailed site-specific investigation and/or
remediation plans to manage the identified hazard.
1.4
Definition of Hydrotechnical Hazards
Hydrotechnical hazards are defined as fluvial or geomorphological conditions that have the potential to cause
water crossing changes that threaten the pipe. Threats to the pipe that may result in pipe damage at water
crossings are assumed to expose the pipe, and then to result in unsustainable structural loadings on the pipe.
Both a pipe exposure and an unsustainable structural loading are necessary to categorize a water crossing as a
threat to the pipeline.
Pipeline exposure may occur due to fluvial or geomorphological changes at the water crossings. In general, the
potential for pipe exposure is a combination of the following factors:

High flow, at water crossings with large contributing watersheds, contributing watersheds subject to high
intensity precipitation and/or impervious soils, and/or the potential for failure of upstream impoundments;

Erodible soils; and

Relatively steep watershed and/or channel slopes as a requirement for high water power sufficient to erode
the water crossing.
Together, these three factors are all needed to expose a pipe by eroding the bed and banks at a water crossing.
Potential mechanisms for pipe exposure include river avulsions (i.e. migration or diversion) to new locations
where the pipe burial is not sufficiently deep, scour along the pipeline right of way (ROW) where a relatively
small creek may start to flow along the pipeline and expose the pipe over a long distance (i.e. resulting in a long
unsupported pipe), or localized bed scour and bank erosion.
Hydrotechnical hazards at water crossings are qualitatively graded as Low, Moderate, or High based on the
interpretation of mapped, reported, observed, measured and/or calculated characteristics, and based on
professional judgment. The hydrotechnical hazard categories are defined as:

High = Potential for an unsupported pipe with external loadings that could contribute to pipe damage.
Further detailed engineering evaluations are recommended at these existing crossings. Remediation may
be required.

Moderate = Potential for a pipe exposure with some possibility for an unsupported section and low potential
for external loading. Ground-based monitoring and inspections should be considered.

Low = Potential for pipe exposure but without the possibility of resulting in an unsupported section.
2.0
PHYSICAL SETTING
About 3,000 km of existing Right-of-Way (ROW) in the TransCanada Mainline Corridor between Burstall
Saskatchewan and Ottawa Ontario were assessed. The ROW consists of two distinct portions, the Western and
Central Pipeline Sections.
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Western Pipeline Section
The Western Section of the EE Conversion pipeline crosses the Interior Plains of Saskatchewan and Manitoba,
including a relatively dry agricultural landscape in western Saskatchewan, and the Manitoba escarpment – a
sandy former beach line of the glacial lake Agassiz. The major river along this alignment is the Assiniboine
River which is crossed at two locations.
Central Pipeline Section
The Central Section of the EE Conversion pipeline crosses the Red River valley in Manitoba and northern
Ontario. It traverses the Interior Plains, Shield, and St. Lawrence Lowland Physiographic regions from west to
east, respectively. The majority of the alignment crosses through the Shield Region, with the exception of
approximately 130 km at the westernmost end of the alignment which crosses the Interior Plains, and
approximately 200 km at the easternmost end which crosses the St. Lawrence Lowlands.
The Interior Plains are generally characterized by relatively flat to gently rolling topography. The major rivers
crossed by the pipeline within this region include the La Salle, Red, and Seine Rivers, from west to east,
respectively.
The Shield is composed of crystalline Precambrian rocks which formed during several phases of mountain
building between approximately four billion and one billion years ago. The region has remained relatively stable
during the last billion years, allowing the landscape to erode slowly to a level or low undulating surface. There
are numerous river, lake and wetland crossings throughout this landscape.
The St. Lawrence Lowlands are characterized by undulating topography formed by glacial and marine deposits
overlying sedimentary rocks. Approximately 13,000 years ago, the Champlain Sea formed along the Shield-St.
Lawrence Lowland border and formed sandy terraces. The terraces have since been partially eroded by
postglacial streams.
3.0
3.1
METHODS
Water Crossing Inventory
At TransCanada’s request, the Phase I crossing inventory was updated based on further desktop work to include
the following additional attributes:

Length of upstream hydrography (derived by GIS algorithm as a surrogate for watercourse size);

Watercourse size classification (MINOR or MAJOR based on an assumed classification threshold of 50 km
of upstream hydrography). The 50 km threshold was selected to differentiate approximately the largest
10% of crossings;

Flow accumulation units (derived by GIS algorithm as an rough index of the size of the contributing
watershed area); and

Navigation Protection Act Classification based on the scheduled waters listed in the Act.
These attributes, where available, have been added to the water crossing inventory in Table A-1 (Appendix A)
and Table B-1 (Appendix B) for the Western and Central Sections of the EE Conversion pipeline, respectively.
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This information is intended to provide a basis for comparing the relative size of the watercourses at each
crossing.
The distance or stationing of the water crossings along the pipeline are based on the distance from the closest
TransCanada mainline valve location (MLV). Water crossings (WC) are identified based on the distance east of
the nearest MLV station along the pipeline (e.g. WC 41+5.2 denotes 5.2 km east of MLV 41).
3.2
Field Investigations
Golder conducted field investigations at 53 of the 55 crossings between October 29 and November 9, 2013 to
collect information for hydrological and hydraulic analysis, for channel scour assessments, and for characterizing
the hydrotechnical hazards. Access was restricted to two crossings (WC 1209+3.826 and WC 1209+5.432)
located near the Canadian Forces Base in Petawawa Ontario where field investigations could not be completed.
Future investigations are planned at these crossing locations.
The crossings were accessed by helicopter and the following site-specific measurements and observations were
collected:

Bankfull width and depth: the width and depth of the channel at bankfull discharge or the point at which
water begins to flow across the floodplain. The bankfull channel serves as a morphological index that can
be related to the formation, maintenance and dimensions of the channel as it exists under the modern
climatic regime. At most locations, the watercourses were too deep and fast-flowing to be waded and
bankfull depth was measured relative to the water surface; the water depth was therefore visually
estimated.

Floodplain width: the extent of the valley floor adjacent to the watercourse to a height of 1.5 m above the
bankfull stage. Measurements were taken along the proposed pipeline alignment and perpendicular to the
direction of stream flow.

Water surface slope: considered an indicator of channel slope; water surface slope influences the
discharge and sediment transport characteristics in a stream.

Wetted width and surface flow velocity: at the time of the site visit.

Bank and bed material composition: observations of the grain size, grading, angularity, consistency and
organic content provide an indication of the potential for channel scour and other types of erosion.

Channel and floodplain roughness coefficients: estimates were based on observations of bank and bed
material composition, and vegetative cover, to support hydraulic analysis and assessments of potential
erosion.

Erosional and depositional features: both active and historical, to provide an indication of the
geomorphic processes that are occurring at the water crossing. Observations of under-cutting and
sloughing/slumping of stream banks, valley slope erosion and instability, development of channel bars, and
presence of islands were recorded.

Channel cross-section data: estimated channel cross-sections were collected where possible at small
watercourses.
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
Beaver dam dimensions: height and width of upstream beaver dams (if observed) were measured and
recorded.

Hydraulic controls: the presence of culverts, bridges, channel constrictions and bedrock outcrops
upstream and/or downstream of the crossing was noted.
This information has been compiled as additional attributes of the priority water crossings in Table C-1
(Appendix C) and Table D-1 (Appendix D) for the Western and Central Sections of the EE Conversion pipeline,
respectively.
3.3
Hydrological Analysis
3.3.1
Watershed Areas
A key attribute for the assessment of hydrotechnical hazards at a water crossing is the contributing watershed
drainage area. Watershed area is needed to estimate the design flow for channel bed scour assessments. The
watershed area at priority crossings was estimated using a combination of information sources and methods
including:

Published watershed areas for Water Survey of Canada (WSC) hydrometric stations located at or near the
water crossings (where available);

Agriculture and Agri-Food Canada’s Watershed Delineation Tool (WDT). The WDT is a publically
accessible online GIS-based tool that uses several layers to delineate gross drainage area boundaries.
The underlying data is a Digital Elevation Model (DEM) of the 1:50,000 Canadian Digital Elevation Data
(CDED) product of Natural Resources Canada et al., and the National Elevation Dataset (NED) authored
and maintained by the United States Geological Service (USGS). The WDT is only available within the
agricultural extent of the Canadian Prairies;

ESRI ArcHydro GIS modelling using a 30 m SRTM raster elevation data set;

The Ontario Ministry of Natural Resource’s Ontario Flow Assessment Tool III (OFAT); an online, spatiallybased application that automates a series of labour-intensive technical hydrology tasks, including
watershed delineation and characterization; and

Manual area measurements using 1:50,000 National Topographic System maps.
The selection method was based on the availability of information, on a review of the calculated watersheds
against available topography plus hydrography and satellite imagery, and on professional judgment. Watershed
areas at the priority crossings along the Western and Central Pipeline Sections are provided in Table C-1
(Appendix C) and Table D-1 (Appendix D), respectively.
3.3.2
Design Flow
The following design flows are required inputs to channel bed scour calculations and were estimated for each of
the crossings as part of the Phase II assessment:
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
The annual maximum daily mean flow with a return period of 2-years. This flow typically represents the
bankfull flow, or point of incipient flooding when the rising water level begins to flow across the floodplain,
and is generally considered to be the channel forming flow.

The annual maximum instantaneous flow with a return period of 100 years. This flow is a typical design
flow used in Canada for pipeline burial at river crossings.
The analysis was primarily based on daily mean flows and annual maximum instantaneous flows recorded at
WSC hydrometric stations located close to the water crossings. As much as possible, stations were selected
with periods of record of 20 or more years. For each WSC station, the following analyses were completed:

Compilation of annual maximum daily mean flows over the period of record;

Frequency analysis of annual maximum daily mean flows to estimate the 2-year and 100-year return period
peak flow; and

Linear regression of annual maximum instantaneous flows and annual maximum daily mean flows to
estimate the crossing-specific peaking factor. A peaking factor is used to convert annual maximum daily
mean flows to annual maximum instantaneous flow in cases where the annual maximum instantaneous
flow is missing from the gauging station records.
The annual maximum daily mean flow with return periods of 2 years and 100 years at the pipeline water
crossings were then estimated using one of the following two approaches:

Pro-rating the 2-year and 100-year flood flows for a Water Survey of Canada stream gauging station
located on the same watercourse, based on a comparison of measured watershed areas; and

Completing a regional analysis of nearby Water Survey of Canada (WSC) stream gauging stations in the
same basin, watershed or ecoregion to derive power regression equations for the 2-year and 100-year
flood flow based on watershed area.
The annual maximum instantaneous flow with a return period of 100 years were computed at each pipeline
crossing by multiplying the corresponding annual maximum daily mean flows with peaking factors. Where
annual maximum daily mean flows were estimated by proration, the peaking factor for the WSC station located
on the same watercourse was used. Where annual maximum daily mean flows were estimated using regional
frequency analysis, peaking factors were calculated using a logarithmic regression equation relating the peaking
factor to watershed area using the same WSC stations used for the regional frequency analysis.
In Ontario, particularity in the northern areas, the availability of WSC hydrometric data is limited and
representative data for several priority crossings could not be obtained. In these instances, the Ministry of
Natural Resource’s Ontario Flow Assessment Tool III (OFAT) was used to estimate the 2-year and
100-year flood flow. The OFAT employs a multiple regression analysis to estimate instantaneous peak flood
flows for ungauged watersheds. The analysis considers watershed factors such as drainage area, main channel
slope, lake and wetland area, mean annual runoff and precipitation and shape factor. Peaking factors, selected
based on professional judgement, were used to convert 2-year instantaneous peak flows to 2-year maximum
mean daily flows.
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3
In cases where the estimated 100-year peak instantaneous flood flow was less than 2.6 m /s (for very small
3
watercourses), a design flow of 2.6 m /s was assumed to account for the possibility of upstream beaver dam
failure. This design flow is representative of the failure of one very large beaver dam or of several average-sized
beaver dams failing in series.
The design flows estimated for the priority crossings along the Western Pipeline Section are included as
attributes in Table C-1 (Appendix C), and for the priority crossings along Central Pipeline Section in Table D-1
(Appendix D).
3.4
Hydraulic Analysis
The estimated hydraulic characteristics for the channel and floodplain were also estimated. The hydraulic
analysis was based on the results of the hydrological analysis plus the local morphological characteristics of the
river.
Uniform open channel flow was assumed to estimate the hydraulic characteristics in the channel and floodplain
at each of the crossings. For the purpose of this assessment, an idealized compound cross-section was
assumed, consisting of a trapezoidal channel with equal side slopes bounded by left and right overbanks with
equal cross slopes. The cross-section properties were selected based on the site-specific measurements and
observations collected during the field investigations.
The estimated hydraulic characteristics are provided in Table C-1 (Appendix C) and Table D-1 (Appendix D) as
attributes for crossings along the Western and Central Pipeline Sections, respectively. Channel velocity
estimates, when considered together with channel bank and bed material, are needed to estimate the stream’s
potential for erosion. Flow top width provides an estimate of the potential length of pipeline that could be
affected by erosion.
3.5
Bed Scour Assessment
A screening level assessment of potential channel bed scour was carried out for a 100-year flood. Channel bed
scour was estimated following the U.S. Bureau of Reclamation’s technical guidelines for computing bed scour
(Pemberton and Lara, 1984). The scour calculation uses the three regime equations identified below, supported
by field observations. Engineering judgment is used to select the most applicable result. The estimated
maximum scour depths are relative to the channel thalweg (i.e. the deepest part of the channel) and are
provided in Table C-1 (Appendix C) and Table D-1 (Appendix D).
The Neill equation provides an estimate of the scour depth from the bankfull hydraulics of an incised reach of
river as defined below:
Where:
𝑞𝑞𝑓𝑓 𝑚𝑚
𝑑𝑑𝑓𝑓 = 𝑑𝑑𝑖𝑖 � �
𝑞𝑞𝑖𝑖

df is the scoured depth below design floodwater level (m);

di is the average depth at bankfull discharge in incised reach (m);
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
qf is the design flood discharge per unit width (m /s/m);

qi is the bankfull discharge in incised reach per unit width (m /s/m); and

m is an exponent varying from 0.67 for sand to 0.85 for coarse gravel.
3
The Lacey equation considers the design flood hydraulics and the grain size of the bed and bank material in the
estimation of channel scour as defined below:
𝑄𝑄 1/3
𝑑𝑑𝑚𝑚 = 0.47 � �
𝑓𝑓
Where:

dm is the mean depth at design discharge (m);

Q is the design discharge (m /s); and

f is Lacey’s silt factor defined as 1.76 (Dm)
(mm).
3
1/2
where Dm is equal to the mean grain size of the bed material
The Blench equation for zero bed sediment transport similarly estimates scour depth from the design flood
hydraulics and grain size of the bed and bank material. The equation is defined as:
𝑑𝑑𝑓𝑓𝑓𝑓 =
Where:
𝑞𝑞𝑓𝑓 2/3
𝐹𝐹𝑏𝑏𝑏𝑏 1/3

dfo is the depth for zero bed sediment transport (m);

qf is the design flood discharge per unit width (m /s/m); and

Fbo is the Blench’s zero bed factor (m/s ) where Fbo is related to the median grain size of the bed material in
a published chart (USBR, 1984).
3
2
The scour depth results obtained from all three equations are adjusted by an empirical multiplication factor Z
(Table 3) to account for channel morphology and hydraulic structures.
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Table 1: Empirical Multiplying Z Factors for use by Regime Equations (Pemberton and Lara, 1984)
Value of Z
Condition
Neill
Lacey
Straight reach
0.5
0.25
Moderate bend
0.6
0.5
0.6
Severe bend
0.7
0.75
0.6
1.0
1.25
Right angle bends
Vertical rock bank or wall
1.25
Nose of piers
1.0
Nose of guide banks
0.4 to 0.7
Small dam or control across river
3.6
Blench
0.5 to 1.0
1.50 to 1.75
1.0 to 1.75
1.5
0.75 to 1.25
Pipe Design and Survey Information
TransCanada provided Pipeline River Crossing Inspection reports, Underwater Inspection/Survey Reports, and
Completion Drawings by email for 24 water crossings on March 26, 2014. These locations included eight priority
crossings. TransCanada also provided pipeline alignment sheets for the priority crossings on October 8, 2014.
The alignments sheets provided information on the presence of river weights or protective coating for
consideration in the assessment of hazards.
The pipe design and pipe cover survey information was used to help refine the hazard ratings. For example,
hazard ratings may be downgraded at some crossings where a continuous coating sufficiently reduces the threat
of external loadings to an exposed pipe. Conversely, the hazard rating may have been elevated if there is a
potential for unsupported river weights along a long unsupported pipeline.
4.0
ASSESSMENT OF HYDROTECHNICAL HAZARDS
The primary purpose of this Phase II assessment was to further characterize the hydrotechnical hazards at
Moderate and High hazard water crossings based on site-specific evaluations and professional judgement, to
confirm/refine the preliminary (Phase I) hazard ratings and to recommend the next steps.
The Phase I assessment identified a preliminary list of 55 water crossings with Moderate and High hazard
ratings (priority water crossings) along the EE Conversion pipeline. This number represented 3% of the total
number of crossings along the pipeline. The priority crossings included 7 Moderate and 1 High hazard crossings
along the Western Pipeline Section, plus 40 Moderate and 7 High hazard crossings along the Central Pipeline
Section.
The priority list has been revised by this Phase II assessment to a total of 36 crossings, which represents a total
of 2% of the mapped crossings along the EE Conversion pipeline. The priority crossings consist of:

Western Pipeline Section of the pipeline: 6 Moderate hazard crossings, and

Central Pipeline Section of the pipeline: 24 Moderate hazard crossings and 6 High hazard crossings
Page 16 of 35
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Rev Date: May 20,
2015
The revised priority list includes water crossings with a variety of observed hydrotechnical hazards. In general,
the hazards that triggered a hazard rating of Moderate or High were:

Large rivers with observed potential for bank erosion or bed scour or with potential upstream channel
avulsions towards intermittent flood channels near the pipeline;

Small creeks with incised channels that flow parallel to the pipeline within the ROW or with the potential for
the creek to migrate into an alignment along the ROW where the fill material may be more erodible than
native material;

Gullies or streams in an actively eroding landscape with the potential for significant down-cutting of the
channel bed in an environment with large rock or other debris nearby; and

Incised channels with enhanced erosion potential due to upstream impoundments (including beaver dams)
that may be breached, including debris associated with a breach.
These hazards have the potential to expose the pipe. Pipe damage was considered a possibility after exposure
due to at least one of the following mechanisms:

Loading of long unsupported pipe sections due to differential settling, or due to exposed pipe sections with
unsupported river weights; and

External loadings such as impacts from hydraulically transported boulders and/or woody debris.
For each of the priority crossings along the pipeline, the coordinates for the start and end locations where the
pipe is subject to hydrotechnical hazards, and the length of pipe affected, were identified and provided as
attributes in water crossing inventory (Appendix C and D). The start and end locations were selected based on
interpretation of local stream morphological characteristics, and on the potential bed scour.
Figure 1 and Figure 2 show the priority crossings along the Western and Central Sections of the EE Conversion
pipeline, respectively. Appendix C (Western Pipeline Section) and Appendix D (Central Pipeline Section)
provide the updated inventory of the priority crossings plus figures illustrating the hydrotechnical hazards.
Detailed descriptions of the crossings are provided in Sections 5.0 and 6.0. The crossings that were reclassified
as Low hazards are identified in Section 7.0.
Page 17 of 35
Rev No: 0
Rev Date: May 20,
2015
³
LEGEND
POPULATED PLACE
!
WATER CROSSING - HIGH HYDROTECHNICAL HAZARD RATING
!
R
!
R
WATER CROSSING - MODERATE HYDROTECHNICAL HAZARD RATING
WESTERN PIPELINE SECTION
HIGHWAY
PROVINCIAL BOUNDARY
Hardisty
!
ALBERTA
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!
SASKATCHEWAN
S:\Clients\Transcanada\Keystone_EastEnergy\99_PROJ\13-1379-0008\05_PRODUCTION\PHASE_II\Rev_0\Western_Pipeline_Overview.mxd
!
Burstall
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Dauphin
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WC-7+17.957
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Herbert
! ! Morse
Swift Current
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Moose Jaw
Regina
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WC-20+20.890
Lake
Manitoba
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Whitewood
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Moosomin
WC-32+8.142
Rapid City
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Brandon
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R
MacGregor Portage la Prairie
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REFERENCE
ROUTE AND VALVE DATA PROVIDED BY CLIENT. SERVICE LAYER CREDITS: IMAGE
COURTESY ESRI, DIGITALGLOBE, GEOEYE, I-CUBED, USDA, USGS, AEX, GETMAPPING,
AEROGRID, IGN, IGP, AND THE GIS USER COMMUNITY
!ROAD DATA OBTAINED FROM GEOBASE®. WATERCOURSE AND
WATERBODY DATA OBTAINED FROM CANVEC.
DATUM: NAD83 PROJECTION: ALBERS EQUAL AREA
50
s of Am eric
50
100
SCALE 1:3,000,000
Canada
United State
0
PROJECT
a
TITLE
150
200
KILOMETRES
ENERGY EAST CONVERSION AND THE
PRIORITY WATER CROSSINGS ALONG
THE WESTERN PIPELINE SECTION
PROJECT NO. 13-1397-0008
DESIGN
NC
30 May. 2014
CHECK
CC
29 Apr. 2015
GIS
REVIEW
SO
MB
29 Apr. 2015
29 Apr. 2015
FILE No. Western_Pipeline_Overview.mxd
SCALE AS SHOWN
REV. 0
FIGURE: 1
300000
800000
1300000
Manitoba
Quebec
LEGEND
³
POPULATED PLACE
!
WATER CROSSING - HIGH HYDROTECHNICAL HAZARD RATING
!
R
!
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WATER CROSSING - MODERATE HYDROTECHNICAL HAZARD RATING
HIGHWAY
CENTRAL PIPELINE SECTION
PROVINCIAL BOUNDARY
Hudsons
Bay
Lake
Winnipeg
13000000
13000000
Ontario
!
WC 39+6.017
12500000
WC 39+7.532
WC 56+19.984
!
R
WC 76A+1.977
!
R
!
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Lake
Of The
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R
WC 59+7.863
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WC 66+2.059
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WC 66+7.401
Lake
Superior
Un
i te
WC 100+2.404
WC 84A+1.643
!
R
!
R!
R
WC 86+27.993
WC 80+5.938
Lake
Nipigon
WC 75+15.444
WC 99+17.058
WC 100+10.752
WC 101+9.958
WC 102+20.513
WC 73+0.276
dS
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R
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WC 107+2.735
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REFERENCE
WC 1207+21.205
a
SERVICE LAYER CREDITS: IMAGE COURTESY ESRI, DIGITALGLOBE, GEOEYE, I-CUBED,
USDA, USGS, AEX, GETMAPPING, AEROGRID, IGN, IGP, AND THE GIS USER COMMUNITY.
ROAD DATA OBTAINED FROM GEOBASE®.
CENTRELINE AND VALVE STATION DATA OBTAINED FROM CLIENT.
DATUM: NAD83 PROJECTION: CSRS ONTARIO MNR LAMBERT
WC 1209+5.432
Lake
Nipissing
!
R
!
R
WC 1209+3.826
200
0
200
SCALE 1:6,000,000
Lake
Michigan
Lake
Huron
PROJECT
Georgian
Bay
12000000
Portage la Prairie
!
Winnipeg
!
!
R
!
R
12000000
!
S:\Clients\Transcanada\Keystone_EastEnergy\99_PROJ\13-1379-0008\05_PRODUCTION\PHASE_II\Rev_0\Central_Pipeline_Overview.mxd
!
Lake
Manitoba
!
Lake
Ontario
TITLE
KILOMETRES
ENERGY EAST CONVERSION AND THE
PRIORITY WATER CROSSINGS ALONG
THE CENTRAL PIPELINE SECTION
PROJECT NO. 13-1397-0008
DESIGN
NC
30 May. 2014
CHECK
CC
29 Apr. 2015
GIS
300000
800000
1300000
REVIEW
SO
MB
29 Apr. 2015
29 Apr. 2015
FILE No. Central_Pipeline_Overview.mxd
SCALE AS SHOWN
REV. 0
FIGURE: 2
5.0
HIGH HAZARD CROSSINGS
The following section provides a detailed description for each of the High hazard water crossings, in order from
West to East.
5.1
5.1.1
WC-39+7.532 Red River
The central pipeline section crosses the Red River upstream of the City of Winnipeg in southwestern Manitoba.
The Red River is a large, international river with its headwaters in the United States flowing northwards to its
mouth in Lake Winnipeg, Manitoba.
Within the ROW, the river has a channel width of about 139 m, a 0.3% gradient, and flow along a valley that is
greater than 1,000 m wide. The river is characterized by irregular meanders, and the pipeline crossing is located
at the downstream end of a meander bend. The river bed and banks are composed of a silty clay substrate, and
potential channel scour of 0.8 m was estimated for a 100-year flood event. Rock riprap protection has been
installed along both banks; however, sloughing of both banks at the upstream end of the ROW (where riprap
protection was absent) was observed during the field investigation.
Exposure of the pipeline could occur due to progressive failure of the river banks. Pipe damage could result
from external loadings along an unsupported pipe section if the pipe becomes exposed.
The recommended next step is to undertake a water crossing survey, including measurement of cover depth,
and to determine appropriate remedial measures (if required).
5.1.2
WC-54+1.763 Wabigoon River
The pipeline crosses the Wabigoon River approximately 4 km northwest of the City of Dryden in northwestern
Ontario. Flow along the river is regulated by a dam at the outlet of Wabigoon Lake upstream of the crossing,
and by a bridge road crossing and a second dam downstream of the crossing.
The river crosses the ROW as an incised, 69 m wide channel with a 0.4% gradient within a 100 m wide valley.
The river bed is composed of silt and clay, and the river banks of clay. The right bank appears to be
encroaching into the channel cross-section within the ROW based on aerial imagery and visual observations
made during ground investigations, creating a flow constriction. Scour of the river banks was observed in some
areas during the field investigation.
The pipeline on the right bank is exposed over a 4 m length, based on information provided by TransCanada.
Further pipeline exposure at this crossing is possible due to progressive bank erosion and bed scour within the
ROW resulting from the right bank encroachment into the channel and the consequent flow constriction. Pipe
damage could follow as a result of loadings on the long unsupported pipe.
It is recommended that a water crossing survey be undertaken to assess the existing pipe cover over the other
pipe sections and the exposed pipeline be remediated.
Page 18 of 35
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Rev Date: May 20,
2015
5.1.3
WC 56+19.984 Unnamed Creek
This pipeline crossing is located east of the junction between Highways 17 and 622, approximately 42 km
southeast of the City of Dryden in northwestern Ontario. This unnamed creek forms the outflow of Kennabutch
Lake, located about 3 km upstream of the crossing. The creek flows southwards with an irregularly meandering
channel pattern. Within the ROW, the creek has a 3 m channel width, a 0.8% gradient within a 100 m wide
valley. The bed and banks are composed of peaty clay. Within the existing channel, a scour potential of 0.4 m
was estimated for a 100-year flood event.
This crossing is a high hazard location, because the creek flows roughly parallel to the pipeline for about 500 m
and there are multiple beaver dams upstream of the crossing that have the potential to breach and deliver high
flow that could result in channel realignment onto the pipe centreline. Cascading beaver dam failures and
realignment of the channel along the pipeline may result in exposure of the pipeline. Pipe damage could result
from loading on a long unsupported pipe and/or woody debris impacts if the pipe becomes exposed.
and assess survey results to determine appropriate remedial measures (if required).
5.1.4
WC 66+2.059 Dog River
The pipeline crossing of Dog River, located upstream of Dog Lake in northwestern Ontario, occurs at the start of
a very flat river reach where the river transitions from an entrenched channel within a relatively narrow valley to a
river with tortuous meanders for the remaining 25 km (valley length) to Dog Lake. The tortuous meanders are
the result of sediment deposition along the slow moving channel, which has a near-zero channel gradient for
about 10 km starting near the crossing location. The meanders along this flat reach tend to form cut-offs and
corresponding oxbows. The river has an approximately 48 m wide channel, and a 0.4% gradient within the
ROW. The valley width is more than 1,000 m. The river bed is composed of silty sand with a trace of rocks, and
its banks of fine sand and some clay. The bed scour during a 100-year flood event was estimated to be 0.9 m.
At the crossing location, the left bank in the outside meander bend upstream of the crossing is protected with
rock riprap and wooden stakes. Sloughing of the bank is exposing the stakes upstream of the bank protection.
The pipeline is threatened by a potential meander cut-off at the crossing location which could re-align the river
onto the pipe centreline and expose the pipeline.
5.1.5
WC 84A+1.643 Flynne Creek
Flynne Creek forms the outflow of the Flynne Lake complex of three lakes situated along Highway 11 about
60 km east of Longlac, Ontario. The creek crosses the pipeline at two locations, but the hazardous crossing is
the most downstream location where the creek flows roughly parallel to the pipeline for about 200 m. This
crossing is located immediately upstream of the creek transition from a relatively steep channel in a defined
valley to a channel with tortuous meanders in a flat wide floodplain. The outflow from the bottom lake appears to
be controlled by a beaver dam, and additional beaver dams are located between the lakes and the crossing.
Page 19 of 35
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2015
Flynne Creek flows across the ROW as a 7 m wide channel with a 0.7% slope and a 170 m wide valley. Its bed
is composed of sand and gravel with a trace of boulders, and its banks are silty clay with some peat. The
channel banks are stabilized with riprap across the ROW. Potential bed scour of the existing channel may be up
to 0.3 m for a 100-year flood.
The pipeline at the creek crossing may become exposed due to cascading failures of upstream beaver dams
located between the crossing and the upstream lakes. Beaver dams in this vicinity could impound a relatively
large volume of water resulting in potentially high breach flows. High flows could cause a diversion of the creek
as a result of bank erosion or erosion of a new channel around a debris jam. The diversion could settle into a
new alignment along the pipe centreline, where the new channel could expose a long unsupported section of
pipe.
5.1.6
WC 106A+3.461 Unnamed Creek
This unnamed creek is located within the Round Lake watershed in northwestern Ontario. The creek flows
eastwards and it is crossed by the pipeline about 100 m upstream of its confluence with Crooked Creek.
Crooked Creek forms part of the Blanche River drainage system. The creek is characterized by an irregular
channel pattern. There are multiple beaver dams for about 2 km upstream of the crossing, with several of the
dams up to 2 m in height. Flow through the nearest beaver dam is partially controlled by a culvert.
The creek flows across the ROW in a channel approximately 7 m wide with a 2.9% gradient down and along the
5-10% sloped valley wall on right bank of Crooked Creek. The creek bed and banks are composed of silty clay.
An estimated scour potential of 0.5 m was calculated for a 100-year flood event.
The hydrotechnical hazards to the pipeline at this location arise from the potential for cascading beaver dam
failures with associated high flows and debris loads. Potential washout of the pipe cover could result in
exposure of the pipeline. Pipe damage may occur due to loading created by differential settling of a long
unsupported pipe, subject to a structural pipe assessment.
6.0
MODERATE HAZARD CROSSINGS
The following sections provide a further description for each of the moderate hazard water crossings, in order
from West to East.
6.1
6.1.1
Western Pipeline Section
WC 7+17.957 Swift Current Creek
Swift Current Creek is a south tributary of Diefenbaker Lake in southwestern Saskatchewan, which is used for
recreation and water supply. The pipeline crosses the creek approximately 12 km upstream of the lake. The
channel pattern consists of irregular meanders, and channel bars are present indicating erosion and deposition
processes are active. The creek is incised with a channel width of 33 m, a gradient of 1.4% across the ROW,
Page 20 of 35
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Rev Date: May 20,
2015
and flows through a 67 m wide valley. The creek bed and banks are composed of till with cobbles and boulders
(up to 0.5 m diameter).
At the upstream end of the ROW, sloughing of the left bank at the toe of the fill slope is occurring due to the
current flow configuration with flow directed across the channel at the toe of the fill slope. Scour pools were also
observed in the creek bed within the ROW, plus erosion of the left valley slope downstream of the ROW.
There is potential for pipeline exposure due to progressive down-cutting of the creek bed, as evidenced by the
channel entrenchment. Scour of the creek bed and banks during flood events due to the erosive power of high
velocity flows is also possible; the estimated scour during a 100-year flood is 1.2 m.
6.1.2
WC 14+16.565 Moose Jaw River
The pipeline crossing of Moose Jaw River is located approximately 18 km downstream of the City of Moose Jaw
in south-central Saskatchewan. The river is a south tributary of the Assiniboine River and is characterized by
irregular meanders and a few channel side bars. The river has a channel width of 32 m, a 0.3% gradient within
the ROW, and flows through a 344 m wide valley. Bluffs along the banks are about 4 m high immediately
upstream and downstream of the ROW. The river bed is composed of sandy silt with some gravel, and the river
banks are generally a sandy till.
During the field investigation, it was noted that rock riprap had been installed in areas on both banks in the
ROW. However, failure of the left bank was also observed on both banks at the downstream end of the ROW.
Exposure of the pipeline could occur due to progressive bank erosion and scour of the riverbed during flood
events. The potential scour of up to 1.1 m was estimated for a 100-year flood event.
6.1.3
This unnamed creek is a small south tributary of Pipestone Creek in southeastern Saskatchewan. The pipeline
crosses the creek about 8 km upstream of the confluence of the two streams. The creek has a sinuous channel
pattern, and is characterized by numerous man-made impoundments along its length. The creek has a channel
width of 2.5 m, a 3.8% gradient within the ROW, and flows through a 25 m wide valley. The creek bed and
banks are composed of till, sand, and gravel, with a trace of cobbles. Two man-made dams have been
constructed approximately 70 m upstream of the crossing. The two impoundments are connected by culverts
and a spillway.
The hydrotechnical hazard at this crossing arises from the possibility of cascading dam failures with associated
high flow and debris (including debris from the dams) that could scour of the creek bed and banks and result in
exposure of the pipeline. Channel scour of up to 0.3 m along the existing channel is estimated during a 100year flood event, which is not likely sufficient to expose the pipe (depending on the existing depth of cover).
Progressive down-cutting of the creek bed over time also has the potential to expose the pipe.
Page 21 of 35
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Rev Date: May 20,
2015
6.1.4
WC 21+13.521 Pipestone Creek
Pipestone Creek originates in southeastern Saskatchewan, flows southeasterly into Manitoba across agricultural
areas, and forms part of the international Souris River Basin. The pipeline crosses Pipestone Creek about 1.5
km downstream of a large man-made impoundment. There are several beaver dams in the reach between the
impoundment and the crossing. The creek is a 52 m wide wetland channel with a 0.6% gradient in the ROW,
within a 290 m wide valley. The creek bed is comprised of silty clay, and its banks of clay with some sand, fine
gravel and a trace of cobbles. The creek has a channel pattern of irregular meanders.
Flow across the ROW is regulated by three culverts under a roadway located about 25 m downstream of the
crossing. At the time of the field investigation, the west culvert was completely blocked with sediment, and the
east culvert was blocked by fallen fence posts.
Channel avulsion due to blockage of the culverts could result in washout of the fill material along the pipeline
alignment. Cascading dam (man-made and beaver) failures with associated high flow and debris could also
occur, leading to scour of the creek bed and banks. Scour of 0.7 m was estimated for a 100-year flood event.
6.1.5
The pipeline crosses this unnamed creek about 5 km northwest of the community of Firdale in south-central
Manitoba. The creek forms the outflow from Belous Lake, located approximately 1.5 km upstream of the
crossing. The creek has an irregular channel pattern in an eastward direction down the Manitoba Escarpment
where it eventually joins Pine Creek. The creek flows roughly parallel to the pipeline for about 1 km, and the
channel has been straightened in several locations to provide improved drainage or to prevent the stream from
flowing along the pipeline.
Within the ROW, the creek has a channel width of 2 m, a 0.5% gradient and a valley greater than 1,000 m wide.
Downstream of the crossing, the channel gradient steepens to about 2.5%. The creek bed is composed of silty
clay and organics, and the creek banks are silty sand. The scour potential is only about 0.1 m during a 100-year
flood event.
During the field investigation, a ditch and a pipe-culvert at the crossing were observed to be in poor condition.
Sloughing of the left and right valley slopes were also noted within the ROW.
There are multiple beaver impoundments upstream of the crossing, and outflows from Belous Lake appear to be
controlled by a beaver dam. A beaver dam failure can trigger additional cascading failures that result in a
relatively high flow with the potential to erode the steep downstream areas, resulting in head-cut erosion towards
the pipeline crossing that may be in excess of the calculated scour potential.
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2015
Together, the site conditions may result in a long-unsupported pipe up to 1 km long if significant head cut
erosion occurred, or if the channel was re-aligned to the pipe centreline. However, there appears to be a
moderate potential for this to occur because Belous Lake appears to be semi-permanent.
6.1.6
WC 32+8.142 Pine Creek
Pine Creek is a south tributary of Whitemud River, which discharges into Lake Manitoba (used for recreation and
fisheries) in south-central Manitoba. The creek has a channel width of 14 m, a 0.4% gradient within the ROW,
and a 780 m wide valley. The creek bed
is composed of silt, and the banks of silt and fine sand. The channel pattern consists of irregular meanders,
and the ROW is located immediately downstream of a severe meander bend. A potential scour depth of 0.3 m
was estimated for a 100-year flood event.
During the field investigation, sloughing of the left bank in the fill slope and erosion of the right bank were
observed within the ROW. Several small beaver dams were also noted upstream of the pipeline crossing.
Pipeline exposure at this crossing could occur due to a local channel avulsion during a high flow event starting at
the upstream meander bend, with erosion focused on the creek’s left bank. High flow would likely be caused by
cascading beaver dam failures upstream of the crossing.
6.2
6.2.1
WC-39+6.017 La Salle River
The La Salle River is a tributary of the Red River near the City of Winnipeg in southeastern Manitoba. The
pipeline crosses the La Salle River in the Perrault neighbourhood about 5 km upstream of the Red River
confluence. The river has a channel pattern of irregular meanders and the crossing is located at the
downstream end of a meander bend. The channel has width of 18 m within an 80 m wide valley. The channel
gradient changes from a 2.0% slope at the upstream end of the ROW to about 0.4% slope at the downstream
end. The river bed is composed of silt and sand, and the river banks have fine sand and some clay. A potential
scour depth of 0.8 m was estimated during a 100-year flood event, without consideration of rock riprap
protection. During the field investigation, it was noted that rock riprap has been installed on the river bed and
river banks within the ROW. Under-cutting of the right bank was observed where the riprap protection is absent
on the outside meander bend. There is a large scour pool in the river bed where the channel gradient changes.
Exposure of the pipeline could occur as a result of channel migration due to land use changes (e.g. dyking
between La Salle River and Red River), and progressive erosion of the river banks and scour of the river bed.
The potential and magnitude of river changes due to land use have not been confirmed by analysis.
Page 23 of 35
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2015
6.2.2
WC-59+7.863 Gulliver River
The pipeline crossing of the Gulliver River is located about 12 km southeast of Ignace in northwestern Ontario,
along the TransCanada Highway (Highway 17). The river has an irregular channel pattern for several kilometres
upstream and downstream of the crossing. The channel is about 62 m wide with a gradient of 0.4% within a
79 m wide valley. The river bed is composed of silty clay and organics, and the river banks are silty sand, with
some gravel and a few boulders. Rock riprap has been installed on the river bed and banks at the crossing.
Potential scour during a 100-year flood event was estimated to be 1.5 m, without rock riprap protection.
Exposure of the pipeline could occur with failure of the riprap protection and consequent scour of the river bed
and erosion of the river banks.
6.2.3
WC-66+7.401 Riviére des Îles
The pipeline crossing of Riviére des Îles is located about 4 km upstream of its confluence with Dog River. The
river is characterized by tortuous meanders and the presence of multiple oxbow lakes. The channel in the ROW
is about 20 m wide with a 0.4% gradient, within a 350 m wide valley. The river bed has a sandy silt substrate,
and the river banks are composed of sand, silt, and some peat. A scour depth of up to 0.5 m in the existing
channel was estimated for a 100-year flood event.
The crossing is located about 50 m downstream of a small bridge road crossing over the river. The pipeline at
this location could be exposed due to scour of the constrained channel downstream of the bridge.
6.2.4
WC-73+0.276 Nipigon River
The Nipigon River flows from Lake Nipigon southwards for about 48 km to Nipigon Bay on Lake Superior. Three
hydroelectric dams are operated on the river between Lake Nipigon and the pipeline crossing. The crossing is
located about 1.4 km downstream of Alexander Dam.
At the crossing, the river has a 134 m channel width, a 0.8% gradient, and a 148 m wide valley. Its bed is
composed of coarse sand with some rocks, and its banks of clay with some fine sand. Rock riprap is installed
on both banks. A potential scour depth of 1.4 m was estimated for a 100-year flood event, without consideration
of the riprap protection.
Pipe exposure could occur as a result of progressive down-cutting of the river in the event of a dam safety issue
resulting in a breach. Dam safety issues are regulated in Canada and the relative hazard associated dam failure
is defined and quantified.
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2015
6.2.5
WC-75+15.444 Postagoni River
The Postagoni River is a southeast tributary of Lake Nipigon, the largest lake entirely within the boundaries of
the province of Ontario. The pipeline crosses the Postagoni River approximately 2 km upstream of its mouth at
Lake Nipigon. The Postagoni River has an irregular channel pattern; however, the crossing is located in the
middle of a straight reach of the river.
The river has a channel width of 22 m and a 0.5% gradient within a 106 m wide valley. Its bed is rocky, and its
banks are composed of silty clay with cobbles and boulders up to 0.5 m in diameter. A potential scour depth of
up to 0.4 m was estimated during a 100-year flood event.
Progressive down-cutting of the river bed over time could result in exposure of the pipeline.
6.2.6
WC-76A+1.977 Unnamed Creek
This unnamed creek forms the outflow of Norami Lake, and is a small north tributary of Blackwater River. The
pipeline crossing is situated approximately 440 m downstream of the lake, and 275 m upstream of a culvert
crossing under Highway 11. The creek flows alongside the pipeline alignment for a distance of about 400 m, on
either side of the crossing. Within the ROW, the creek has channel width of about 7 m, a 0.3% gradient and a
poorly drained valley. The creek bed is composed of silty sand and organics, and its banks consist of clay and
peat. A potential scour depth of 0.5 m was estimated for a 100-year flood event.
Exposure of the pipeline is possible due to the potential washout of fill material along the alignment. Pipe
damage could result from loading of a long unsupported pipe and potential collisions with off-road vehicles.
6.2.7
WC-80+5.938 Kenogamisis River
The pipeline crosses the Kenogamisis River, a west tributary of the Kenogami River, in northwestern Ontario,
approximately 2.8 km downstream of the Kenogamisis Dam. The river forms the outflow of Kenogamisis Lake
and flows northwards with a sinuous channel pattern. The Kenogamisis River has a channel width of about
67 m, a 0.5% gradient, and a 152 m wide valley. Its bed is composed of silty sand, gravel, cobbles and
boulders, and its banks of clay and peat.
A river training structure has been constructed on the left bank at the upstream end of the ROW. Rock riprap
installed in areas on both banks was observed during the field investigation. Bank erosion was evident where
riprap protection was absent. Channel scour of up to 1.4 m was estimated for a 100-year flood event, without
consideration of riprap protection.
Exposure of the pipeline could occur due to overtopping and outflanking of the river training structure during
flood flows, with consequent scour along the pipeline alignment and localized bank erosion and bed scour at the
crossing over time. Pipe damage could result from loading on a long unsupported exposed pipe.
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6.2.8
WC-86+27.993 Nagagami River
The pipeline crosses the Nagagami River north of the T-junction of Highways 11 and 631 in northwestern
Ontario. Nagagami River is an east tributary of Kenogami River and flows northwards with an irregular channel
pattern. Within the ROW, the river has a 50 m channel width, a 0.7% gradient and a 82 m wide valley. The
riverbed is composed of coarse sand, gravel and cobbles, and the riverbanks of fine sandy silt.
The right bank has encroached into the channel cross-section, providing a constriction of the river. A gully is
forming on the right valley slope, and concrete blocks have been installed near the slope toe in an effort to stop
its development. Rock riprap has been placed in areas on both banks of the river within the ROW.
Pipeline exposure is possible at the crossing as a result of under-cutting of the slope toe where the right bank is
encroaching into the channel. Scour of the existing channel during a 100-year event was estimated to be 2.1 m,
without consideration of riprap protection.
6.2.9
WC 97+22.494 Haggart Creek
The central pipeline section crosses Haggart Creek about 9 km west of Smooth Rock Falls in northwestern
Ontario. The creek is characterized by a channel pattern with irregular meanders. There is continuous beaver
activity along the creek with impoundments and remnants of impoundments along the entire channel for several
kilometres both upstream and downstream of the crossing location. The channel is currently controlled by a
small man-made dam, less than 2 m high, and a spillway immediately upstream of the pipeline crossing.
Overall, the upstream impoundments are about 100 m wide and extend at least 4 km upstream. The cascading
failure of these dams could result in very high flows across the ROW.
Within the ROW, Haggart Creek has an approximate channel width of 5 m, a 0.6% gradient and flows through a
160 m valley. The creek bed and banks are composed of silty clay with organics present in the banks. A scour
depth of 0.4 m was estimated for a 100-year flood event.
The channel crosses the pipeline in three locations. Pipe exposure could occur at any of these crossings, but is
more likely to occur at the most upstream (eastern) crossing with a potential to divert along the pipeline for
140 m. Debris jams in this vicinity could also divert the creek along the pipeline to the second water crossing,
resulting in the potential for pipe exposure. Pipe damage could result from loading on a long unsupported pipe.
6.2.10
WC-99+17.058 North Driftwood River
North Driftwood River is a west tributary of Abitibi River in northeastern Ontario, and flows generally northwards
with an irregular channel pattern from the pipeline crossing, located about 6 km northwest of Driftwood. The
river has a 50 m wide channel with a 1.0% gradient and a 150 m wide valley. The North Driftwood River has a
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river bed and banks composed of silty clay with some sand, and a few boulders (up to 0.5 m in diameter) on the
river bed downstream of the ROW.
During the field investigation, erosion scars were observed on the river banks and at the toe of the valley wall.
Deposition is occurring near the right bank at the downstream end of the ROW, above some rapids. Channel
scour of up to 1.2 m was estimated for a 100-year flood event.
Pipeline exposure could occur due to scour of the right bank along the outside meander bend in the ROW,
upstream of the channel bar during high flow events. Pipeline exposure could also result from progressive scour
of the river bed in the constricted channel section at the downstream end of the ROW.
6.2.11
WC-100+2.404 Buskegau River
The pipeline crossing of the Buskegau River is located between the communities of Hunta and Buskegau in
northeastern Ontario. Buskegau River is a west tributary of Frederick House River, and flows generally
northeastwards with an irregular channel pattern from the crossing.
Within the ROW, the river has a 47 m channel width, a 0.8% gradient, and a 146-m wide valley. The river bed
and river banks are composed of silty clay with a trace of sand. There is an island on the inside meander bend
(left bank) immediately upstream of the ROW. Farther downstream, the left bank is encroaching into the
channel where it forms a flow constriction. The potential scour depth for a 100-year flood event was estimated
to be 1.4 m.
Pipeline exposure could occur due to scour of the right bank along the outside meander bend, sloughing of the
left bank to create a further flow constriction, and scour of the river bed in the constricted section.
6.2.12
WC-100+10.752 Frederick House River
The pipeline crosses the Frederick House River about 9 km east of the Buskegau River crossing. This large
river is a tributary of Abitibi River in northeastern Ontario, and flows northwards with an irregular channel pattern
from its headwaters near the City of Timmins to its mouth 33 km northwest of Cochrane. The creek has a 97 m
wide channel, a 0.9% gradient, and a 114 m wide valley. The river bed is composed of silty clay with a trace of
sand, and the river banks are silty sand with some clay. A potential scour depth of 2.1 m was estimated for a
100-year flood event.
The right bank is encroaching into the channel cross-section within the ROW, creating a flow constriction.
During the field investigation, failure of the right valley slope was evident from leaning signposts on the right
bank, and sloughing of the right bank.
There is potential for pipeline exposure at this crossing as a result of scour and sloughing of the left bank, and
scour of the river bed within the constricted channel section.
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6.2.13
WC-101+9.958 Unnamed Creek
The pipeline crossing of this unnamed creek in northeastern Ontario is located about 4 km northwest of Potter
and the T-junction between Highway 11 and Newmarket Concession Road 5. The creek forms part of the
Frederick House River drainage system as a tributary of the Wicklow River immediately downstream of the
crossing. The channel is characterized by irregular meanders, and there are multiple beaver impoundments and
remnants of beaver dams along its length. Within the ROW, the creek has a 4 m wide channel, a 0.9% gradient
and a 60 m wide valley. Its bed consists of silty clay with a trace of sand and rocks, and its banks are silty clay
with some sand. Scour along the existing channel was estimated to be 0.4 m for a 100-year flood event.
Cascading failure of the upstream beaver dams may lead to washout of the valley and exposure of the pipeline.
Bank erosion may also result in sections of exposed pipeline.
6.2.14
WC-102+6.874 Wicklow River
The Wicklow River is crossed by the pipeline in its headwaters about 2 km south of Tunis in northeastern
Ontario. The Wicklow River is a tributary of Frederick House River. The crossing is located about 120 m
downstream of the river’s confluence with a second watercourse. Both streams are characterized by irregular
meanders and multiple beaver impoundments upstream of the ROW.
Within the ROW, the river has a 25 m wide channel, a 0.8% gradient and flows through a 53 m wide valley. The
riverbed is composed of clay and some silt, and the riverbanks of silty clay and organics. Potential scour of the
existing channel during the 100-year flood event is estimated to be 1.0 m.
Cascading upstream beaver dam failures, with associated high flows and debris loads, could result in washout of
the valley in the ROW and exposure of the pipeline. Pipe damage could result from loading on long unsupported
pipe.
6.2.15
This unnamed creek originates near Porquis Junction and forms part of the headwaters of Abitibi River in
northeastern Ontario. The pipeline crosses the creek in Porquis Junction, between Highway 67 and Cosens
Road.
The creek is an incised 8 m wide channel with a 2.0% gradient and a 34 m wide valley. Its bed and banks are
composed of a silty clay substrate, with a trace of cobbles on the banks. Riprap is installed on the right bank in
the ROW. Scour of up to 0.7 m was estimated for a 100-year flood event, without consideration of riprap
protection.
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Undercutting of the left bank in the ROW was noted during the field investigation. The breach of a 1.5-m high
beaver dam at the upstream end of the ROW was also in progress.
Pipeline exposure could occur due to progressive down-cutting of the creek, and under-cutting of the creek
banks.
6.2.16
WC-104+19.763 Unnamed Drainages
At this location, the pipeline crosses over agricultural land adjacent to Highway 11 about 2 km northwest of
Ramore in northeastern Ontario. Two gullies are forming downstream of the ROW, which are approximately
20 m x 12 m x 0.2 m (length x width x depth) in size and have about a 4% gradient. Gully erosion is occurring as
a result of drainage from the agricultural land, which has silty clay soils and an approximate 0.5% slope. This
drainage is being collected in narrow furrows directed downslope towards a culvert crossing under Highway 11.
There is potential for exposure of the pipeline at this location if the gully erosion head cuts into the ROW.
damage could result due to of loading created by differential settling of long unsupported pipe.
Pipe
6.2.17
The pipeline crossing of this unnamed creek is located about 1 km west of Ramore in northeastern Ontario. The
creek is formed by two tributary streams which confluence within the ROW. The creek forms part of the Black
River drainage system; Black River being a tributary to Abitibi River near Iroquois Falls. The creek has a 9 m
wide channel with a 7.1% gradient and straight channel pattern, and a 30 m wide valley. The creek bed and
banks are composed of a peaty clay substrate with some sand. During the field investigation, it was noted that
rock riprap is installed on the creek bed and banks. The estimated potential scour depth is 1.2 m for a 100-year
flood event.
Exposure of the pipeline could occur at this crossing due to scour of the creek bed downstream of the
confluence of the tributary streams, and due to progressive down-cutting of the creek bed over time.
6.2.18
This unnamed creek is a south tributary of Black River, which in turn forms part of the Abitibi River. The pipeline
crosses the creek approximately 6 km southeast of Ramore in northeastern Ontario. The creek is characterized
by a sinuous channel pattern, and multiple beaver dams are present along its length. At the crossing, the creek
has a 10 m wide channel, a 0.6% gradient, and a 370 m wide valley. The creek bed and banks are composed of
a silty sand substrate; and organics are also present on the creek banks. A potential scour depth of 0.3 m was
estimated for a 100-year flood event.
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Cascading failures of the upstream beaver dams could result in scour of the creek bed and banks. There is also
potential for pipeline exposure due to channel avulsion within the shallow wide floodplain during a flood event
with washout of the fill material around the pipeline. Pipe damage could result from loading created by
differential settling on long unsupported pipe.
6.2.19
WC-107+2.735 Unnamed Creeks
Two unnamed creeks flow eastwards to form a small south tributary of Blanche River. The pipeline crosses
these creeks about 2 km east of the community of Hough Lake in northeastern Ontario, between Highways 11
and Highway 573. The creeks are characterized by a channel pattern of irregular meanders, and multiple
beaver dams along their lengths. The creeks create a wetland area between two beaver impoundments
upstream of the ROW and a third beaver impoundment downstream of the ROW. The nearest upstream beaver
dam is 1.7 m high and approximately 37 m long. The main creek channel is about 5 m wide with a 1.7%
gradient in a 200 m wide valley. Its bed and banks are composed of silty clay with a trace of sand, covered with
organics.
Cascading beaver dam failures upstream of this crossing could result in channel scour and washout of the fill
material around the pipeline. Scour of the creek bed and banks may occur during other high flow events,
especially at the confluence of the two creeks. A scour depth of 0.2 m was estimated for a 100-year flood event.
There is also a potential for a channel avulsion within the shallow valley which could result in pipeline exposure.
Pipe damage could occur from loading created by differential settling of long unsupported pipe.
6.2.20
This pipeline crossing is located about 125 m southeast of the crossing WC-107+5.812, along the pipeline
alignment. The pipeline crosses an unnamed creek that flows northwards to join the unnamed creek at
WC-107+5.812. The channel is characterized by an irregular channel pattern. Multiple beaver dam
impoundments were also noted at the upstream end of the ROW. The creek is about 19 m wide channel with a
1.6% gradient and a 39 m wide valley. The creek bed is composed of sand, sandy clay and some organics, and
the stream banks are silty clay with some sand and gravel. A scour potential of 0.8 m was estimated for a 100year flood event. During the field investigation, it was noted that rock riprap has been installed on the stream
bed and banks.
Exposure of the pipeline could occur due to potential for cascading beaver dam failures or channel avulsion to
another alignment across the ROW. Pipe damage could result from loading created by differential settling of
long unsupported pipe.
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6.2.21
This unnamed creek is located within the Englehart River watershed in northern Ontario. The creek flows
westwards and is crossed by the pipeline about 1 km downstream of the TransCanada Highway 11. Flows in
the creek at the crossing are controlled by a wooden dam and pipe culvert located at the downstream end of the
ROW. There are multiple beaver dams along the creek length upstream of the crossing.
The creek is an incised 6 m wide channel with a 3.8% gradient and a 19 m wide valley. The creek bed is
composed of silty clay with some sand, and the banks of silty clay with some organics. The relatively high
channel slope at the pipeline ROW is part of the transition from a 20 m deep valley to a 10 m deep valley over a
distance of about 300 m. Together, these site conditions suggest that the valley morphology may be relatively
immature and subject to progressive deepening due to scour or head-cut erosion by up to 5 m near the pipeline
ROW. Potential channel scour of 0.8 m could occur during a 100-year flood event.
Pipeline exposure could occur due to cascading beaver dam failures, and progressive deepening of the valley
due to scour or head-cut erosion within the ROW.
6.2.22
WC-1207+21.205 Walkers Creek
The pipeline crosses Walkers Creek about 400 m south of Sullivan Lake in northern Ontario. The creek forms
the outflow of the lake and flows generally southeastwards to its confluence with Kennedy Creek, located
approximately 10 km downstream of the crossing.
The creek flows across the ROW in a 7-m wide channel with a straight channel pattern and a 2.2% gradient
through a 170 m wide valley. The creek bed is composed of silty coarse sand and organics, and the stream
banks of silty peat and some organics. During the field investigation, multiple beaver dams were noted at the
upstream end of the ROW. Flows in the creek are regulated by a culvert road crossing located within of the
ROW.
Exposure of the pipeline could occur due to cascading beaver dam failures and/or blockage of the culverts in the
ROW leading to high flow and washout of fill material along the pipeline alignment. The potential scour depth
along the existing channel is estimated to be 0.2 m.
Pipe damage could result from loading created by
differential settling of long unsupported pipe, off-road vehicle collision and/or woody debris impacts if the pipe
becomes exposed.
6.2.23
WC-1209+3.826 Chalk River
The Chalk River originates at Corry Lake and flows northeastwards reaching its mouth at Gwatkin Lake, in
northeastern Ontario. The pipeline crossing under Chalk Lake is located about 2.4 km upstream of Gwatkin
Lake. The TransCanada Highway (Highway 17) is situated about 500 m upstream of the pipeline crossing. A
field reconnaissance at this pipeline crossing was not completed in November 2013 due to access restrictions.
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The crossing is located in a sharp meander bend of the river with a curve radius to channel width greater
than 10 m. The creek flows across the ROW in a 10-15-m wide channel with irregular channel pattern. The
surficial geology at the pipeline crossing is expected to consist of gravel, gravelly sand, and sand. A scour depth
of 0.6 m was roughly estimated for a 100-year flood event, based on channel characteristics interpreted from
available imagery and topography data.
Progressive down-cutting of the channel and localized erosion of the left bank at the crossing, especially during
high flow events have the potential to result in exposure of the pipeline.
6.2.24
WC-1209+5.432 Young Creek
Young Creek is a west tributary of Tucker Creek which flows into Allumette Lake in northeastern Ontario. The
pipeline crossing of Young Creek is located about 900 m upstream of its confluence with Tucker River, and
about 6 km upstream of Allumette Lake. The TransCanada Highway (Highway 17) is situated about 300 m
upstream. A field reconnaissance at this pipeline crossing was not completed in November 2013 due to access
restrictions.
There is an ATV bridge located 20 m upstream of the pipeline crossing. The creek flows through the ROW in an
approximate 10-m wide channel and is characterized by irregular meanders. There are oxbows and meander
cut offs on either side of the ROW. The surficial geology at the pipeline crossing is expected to consist of gravel,
gravelly sand, and sand. A scour depth of 0.4 m was roughly estimated for a 100-year flood event, based on
channel characteristics interpreted from available imagery and topography data. Downstream of the ROW, the
creek flows alongside the pipeline for approximately 30 m.
Migration or re-alignment of the creek could result in exposure of the pipeline. There is also potential for
washout of the ATV bridge upstream of the crossing with resulting scour of the downstream creek bed and
banks.
7.0
LOW HAZARD CROSSINGS
The Phase II assessment resulted in the reclassification of 19 crossings as Low hazards. Reclassification was
based on the following considerations:

Limited scour potential due to channel and valley geometry, erosion resistant soils and/or the presence of
downstream hydraulic controls (e.g., road crossings, bedrock)

Presence of continuous concrete coating around the pipeline protecting the pipe from damage and
increasing the overall diameter of the pipe, reducing the potential for a long unsupported pipeline

Limited potential for channel avulsion or exposure over a long length of pipe due to surrounding topography

Recent pipe cover surveys, indicating sufficient pipe burial depth
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The following crossings were reclassified as Low hazards and were removed from the scope of the Phase II and
future hydrotechnical hazard assessments:










8.0









WC-60+20.116 English River
WC-62+21.418 Little Savanne River
WC-76+8.703 Blackwater River
WC-87+28.08 Kabinakagami River
WC-97+19.51 Poplar Rapids River
WC 107+12.791 Crocodile Creek
WC-1207+15.062 Tee Creek
WC-1209+17.256 Petawawa River
WC-1211+18.987 Snake River
WC-1214+0.203 Madawaska River
WC-1216+3.689 Unnamed Drainage
RECOMMENDED NEXT STEPS
This Phase II assessment has resulted in a revised list of water crossings with Moderate and High hazard
ratings. The next step for TransCanada is to proceed with further detailed engineering evaluations at high
hazard crossings, including depth of cover surveys. Moderate hazard crossings should be considered for
ground-based monitoring. Site specific next steps for the Moderate and High hazard crossings are described in
the detailed descriptions above (Sections 5.0 and 6.0) and on the crossing overview figures presented in
Appendices C and D.
9.0
CLOSING
This assessment consisted of a site-specific evaluation of the hydrotechnical hazards at selected water
crossings along the EE Conversion pipeline. It is intended to help prioritize water crossings for future
assessment and remediation efforts. The identification and classification of hydrotechnical hazards at the
crossings are based on the information and conditions present and available at the time of the assessment. The
assessment results may be revised subject to additional information becoming available.
Page 33 of 35
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2015
Report Signature Page
We trust the above meets your present requirements. If you have any questions or require additional details,
please contact the undersigned.
GOLDER ASSOCIATES LTD.
APEGA PERMIT TO PRACTICE 05122
Prepared by:
Reviewed by:
Adam Auckland, M.Sc., P.Eng.
Water Resources Engineer
Michael Bender, Ph.D., P.Eng.
Principal, Water Resources Engineer
AA/MB/sp
Golder, Golder Associates and the GA globe design are trademarks of Golder Associates Corporation.
https://capws.golder.com/sites/1400899energyeast/document control/rp_reports/rp0051_mainline cooridor hydrotechnical phase ii hazards assessment/rev 0/ee4930-gal-c-rp-0009-0.docx
THIRD PARTY DISCLAIMER
This report has been prepared by Golder Associates Ltd. (Golder) for the benefit of the client to whom it is
addressed. The information and data contained herein represent Golder's best professional judgment in light of
the knowledge and information available to Golder at the time of preparation. Except as required by law, this
report and the information and data contained herein are to be treated as confidential and may be used and
relied upon only by the client, its officers and employees. Golder denies any liability whatsoever to other parties
who may obtain access to this report for any injury, loss or damage suffered by such parties arising from their
use of, or reliance upon, this report or any of its contents without the express written consent of Golder and the
client.
Page 34 of 35
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2015
10.0 REFERENCES
Golder Associates Ltd. (Golder) (2015). Energy East Conversion and the TransCanada Mainline Corridor.
Hydrotechnical Hazards Phase I Assessment, Revision C. Project No. 13-1397-0008 4000. February
2015.
Golder Associates Ltd. (Golder). 2010. Estimate of Water Velocity during Exposure Events near MLV55.
Submitted to TransCanada Pipelines Ltd. June 17, 2010.
MNR (Ministry of Natural Resources). 2014.
User Manual – Ontario Flow Assessment Tool III.
January 20, 2014. http://www.mnr.gov.on.ca. Accessed July 16, 2014.
Pemberton E.L., and Lara, J.M. 1984. Computing Degradation and Local Scour. Technical Guideline for the
Bureau of Reclamation. Denver, Colorado. January 1984.
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Attachment NEB 5.20-1 Phase II Hydrotechnical Hazards Assessment

Transcription

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