Meadowcliffe Drive Erosion Control Project

Transcription

Toronto and Region Conservation Authority
Environmental Study Report
March 1, 2010
5 Shoreham Drive, Downsview, Ontario M3N 1S4
ACKNOWLEDGEMENTS
The Toronto and Region Conservation Authority gratefully acknowledges the efforts and
contributions of the following people participating in the planning and design phases of the
Meadowcliffe Drive Erosion Control Project:
Al Sinclair
Barbara Heidenreich
Beth McEwen
Bruce Pinchin
Councilor Brian Ashton
Councillor Paul Ainslie
Daphne Webster
David Argue
Don Snider
Janet Sinclair
Jason Crowder
Jim Berry
Joe Delle Fave
Joseph Palmissano
Larry Field
Laura Stephenson
Lindsay Prihoda
Lori Metcalfe
Mark Preston
Mike Tanos
Moranne McDonnell
Nancy Lowes
Nick Saccone
Patricia Newland
Paul Albanese
Peter Xiarchos
Susan Scinocca
Sushaliya Ragunathan
Timo Puhakka
Trevor Harris
Tudor Botzan
Meadowcliffe Drive Resident
Ontario Heritage Trust
City of Toronto
Shoreplan Engineering Limited
City of Toronto
City of Toronto
iTransConsulting Limited
Meadowcliffe Drive resident
Terraprobe Limited
iTransConsulting Limited
Guildwood Village Community Association
Terraprobe Limited
City of Toronto
City of Toronto
M.P.P Lorenzo Berardinetti’s Office
M.P.P Lorenzo Berardinetti’s Office
Guildwood Village Community Association
II
EXECUTIVE SUMMARY
Toronto and Region Conservation Authority (TRCA) continues to work towards ensuring
healthy rivers and shorelines, greenspace and biodiversity, and sustainable communities. One
key step in this process is the design and implementation of shoreline stabilization projects
along the Scarborough bluffs. These projects serve to remediate erosion prone zones, and to
rehabilitate and enhance key natural areas and community focal points. Several decades of
important waterfront work has been carried out by TRCA in partnership with waterfront
communities to protect and preserve the waterfront for present and future generations.
TRCA is interested in undertaking remedial erosion control works along a portion of the Lake
Ontario shoreline from Bellamy Ravine to Bluffers Park, one of the last unprotected sectors of
the Scarborough bluffs in the City of Toronto. The project site spans approximately 1,400 m of
shoreline from Bluffers Park, East Beach to Bellamy Ravine (also known as Gates Gully).
At the request of several homeowners who expressed concern over the loss of property and
the potential long-term risk to their homes, TRCA began monitoring erosion rates on
Meadowcliffe Drive in 1985. Several studies have been completed along this shoreline sector;
however the most significant report was a geotechnical report conducted on behalf of TRCA by
Terraprobe in 2006, which identified acceleration in the erosion rate. This study concluded
there would be a significant loss of property and infrastructure, as well as a risk to public safety
if mitigative measures were not undertaken along the Meadowliffe shoreline sector.
TRCA’s project objective is to provide long-term protection against erosion by reducing wave
energy, protecting the toe of the bluffs from wave energy, stabilizing slopes and enhancing
natural processes. As a consequence, risk to public safety and infrastructure will be reduced,
passive recreational opportunities will be increased, and aquatic and terrestrial habitat
conditions as well as aesthetics will be improved. TRCA has examined a number of alternatives
to achieve these objectives including headland beach systems, groynes, and breakwaters.
As part of the Class Environmental Assessment (Class EA) process, TRCA retained Shoreplan
Engineering and Terraprobe to complete a detailed review and analysis of the existing
conditions along the designated project area and assist with the development of alternative
long-term remedial solutions to address the risk to public safety. Results of these investigations
indicate that over the next 100 years, a substantial loss of highly valuable recreational, heritage
and ecological land is projected, affecting numerous residential dwellings along the crest of the
Scarborough Bluffs.
In light of this information, a range of solutions were developed which recognized negative and
positive attributes associated with each. To assist with the evaluation of the alternative options
and provide input into the planning and design process, a Community Liaison Committee or
CLC was formed. Composed of technical staff, stakeholders, provincial agency staff,
community activists and interested members of the public, the CLC became an integral part of
the Class EA process. Through a series of CLC meetings, a range of alternative options were
considered, from traditional solutions such as cobble beaches and breakwaters. In addition to
providing feedback on technical and economic considerations, the members provided great
insight into the importance of preserving the Scarborough Bluffs.
The preferred solution determined through the Class EA process is a shoreline treatment
consisting of cobble beach anchored by a series of parallel headlands which will protect 600
metres (m) of eroding bluff below Meadowcliffe Drive. The headlands will be constructed with
large (3-5 tonne) armour stones, measuring between 80 to 100 m in length and spaced 100 to
150 m apart. The area between the headlands will consist of rubble material covered with a
III
layer of beach cobble. The beach cobbles will be dynamically stable, and the profile shape will
adjust to different wave conditions and water levels over time. The preferred solution also
considers the potential need for a buttress at the base of the bluffs at the east end of the
shoreline sector to reduce slope recession.
TRCA identified five construction access options and evaluated these options to determine the
preferred route. The preferred option is to access the site from the east via TRCA’s existing
service road which provides shoreline access from the Guild Inn. TRCA has taken measures to
address public concerns related to this route to ensure that all impacts are mitigated.
Upon identifying the preferred solution, TRCA completed a detailed environmental analysis to
determine any required mitigation measures. Information gathered through this process has
informed the detailed design process. Working with representatives from City of Toronto,
Ministry of Natural Resources, Fisheries and Oceans Canada, and Transport Canada, TRCA
will prepare a screening report to fulfill the requirements of the Canadian Environmental
Assessment Act. This screening report will facilitate the necessary federal approvals that will
be required to implement the project.
Capital funding for the proposed works has been identified in TRCA’s 2010 – 2014 budget, with
works to be carried out between the period of July 1 – March 31 annually. Given the nature of
coastal interventions over the past 50 years across North America, TRCA anticipates that an
adaptive management approach will be necessary, to allow modifications to the overall design
based on continued monitoring and evaluation of the built structures, shoreline and slope
recession.
IV
TABLE OF CONTENTS
1.0
INTRODUCTION ........................................................................................................................ 1
1.1
1.2
1.3
1.4
1.5
Relationship of the Undertaking to the Environmental Assessment Act.................................. 1
Purpose of the Undertaking .......................................................................................................... 3
Site Description .............................................................................................................................. 3
General Description of the Undertaking ...................................................................................... 5
Rationale for the Undertaking ....................................................................................................... 6
2.0
BACKGROUND.......................................................................................................................... 7
2.1
2.2
2.2.1
2.2.2
2.2.3
2.2.4
2.3
History of the Problem................................................................................................................... 7
Identification of Previous Studies ................................................................................................ 9
Geotechnical Reports .................................................................................................................. 9
Planning Documents ................................................................................................................. 10
Aquatic and Terrestrial Habitat Reports .................................................................................... 12
Socioeconomic and Cultural Heritage Studies ......................................................................... 13
Justification of Conservation Authority Involvement ............................................................... 14
3.0
BASELINE ENVIRONMENTAL INVENTORY ........................................................................... 14
3.1
3.2
3.2.1
3.2.2
3.2.3
3.2.4
3.2.5
Location......................................................................................................................................... 15
Existing Site Conditions .............................................................................................................. 16
Physical Environment ................................................................................................................ 16
Biological Environment.............................................................................................................. 30
Cultural Environment ................................................................................................................. 40
Socioeconomic Environment .................................................................................................... 45
Engineering/Technical............................................................................................................... 46
4.0
DESCRIPTION OF PRELIMINARY ALERNATIVE CONCEPTS ............................................... 48
4.1
4.1.1
4.1.2
4.1.3
4.1.4
4.1.5
4.1.6
4.1.7
4.1.8
4.1.9
Preliminary Alternative Concepts ............................................................................................... 48
“Do-Nothing” Alternative............................................................................................................ 48
Preliminary Concept 1a – Headland Beach, Meadowcliffe Drive only ...................................... 49
Preliminary Concept 1b – Headland Beach, bluff protection over full project site ................... 50
Preliminary Concept 2a – Groyne/headland beach, Meadowcliffe Drive only.......................... 51
Preliminary Concept 2b – Groyne/headland beach, bluff protection over full project site ....... 52
Preliminary Concept 3 – Breakwater + cobble beach .............................................................. 53
Preliminary Concept 4a – Headland/groyne ............................................................................. 54
Preliminary Concept 4b - Headland/groyne + rubble access road.......................................... 54
Preliminary Concept 4c - Headland/groyne + sand beach ...................................................... 54
5.0
EVALUATION OF PRELIMINARY ALTERNATIVE CONCEPTS ............................................... 55
5.1
5.1.1
5.1.2
5.1.3
5.1.4
5.2
5.3
5.3.1
5.3.2
5.3.3
5.3.4
5.3.5
5.3.6
5.3.7
Evaluation Criteria........................................................................................................................ 55
Physical Criteria ......................................................................................................................... 56
Biological Criteria....................................................................................................................... 56
Cultural and Socioeconomic Criteria......................................................................................... 56
Technical and Engineering Criteria ........................................................................................... 56
Public Evaluation of Preliminary Alternatives Concepts.......................................................... 60
Agency Evaluation of Preliminary Alternative Concepts.......................................................... 62
The “Do-Nothing” Alternative .................................................................................................... 62
Preliminary Concept 1a – Headland Beach, Meadowcliffe Drive only ...................................... 62
Preliminary Concept 1b – Headland Beach, bluff protection over full project site ................... 63
Preliminary Concept 2a – Groyne/headland beach, Meadowcliffe Drive only.......................... 63
Preliminary Concept 2b – Groyne/headland beach, bluff protection over full project site ....... 63
Preliminary Concept 3 – Breakwater and cobble beach........................................................... 63
Preliminary Concept 4a – Headland/groyne ............................................................................. 64
V
5.3.8
5.3.9
Preliminary Concept 4b - Headland/groyne and rubble access road ...................................... 64
Preliminary Concept 4c - Headland/groyne and sand beach................................................... 64
6.0
PREFERRED ALTERNATIVE ................................................................................................... 65
6.1
6.2
Refinement of the Preferred Alternative .................................................................................... 65
Description of the Preferred Alternative .................................................................................... 66
7.0
ENVIRONMENTAL SCREENING OF PREFERRED ALTERNATIVE ........................................ 67
7.1
7.1.1
7.1.2
7.1.3
7.1.4
7.1.5
Detailed Environmental Analysis of the Preferred Alternative ................................................ 67
Physical Environment ................................................................................................................ 70
Biological Environment.............................................................................................................. 73
Cultural Environment ................................................................................................................. 74
Socioeconomic Environment .................................................................................................... 75
Engineering/Technical............................................................................................................... 76
8.0
DESCRIPTION OF ALTERNATIVE CONSTRUCTION ACCESS.............................................. 76
8.1
8.2
8.3
8.4
8.5
Alternative 1 – Bluffers Park Access Route ............................................................................... 77
Alternative 2 – Marine Access Route ......................................................................................... 78
Alternative 3 – Guild Inn Access Route...................................................................................... 78
Alternative 4 – Bellamy Ravine Access Route........................................................................... 79
Alternative 5 – Top Dumping....................................................................................................... 80
9.0
EVALUATION OF ALTERNATIVE CONSTRUCTION ACCESS OPTIONS ............................... 80
9.1
9.2
9.3
9.4
9.5
Alternative 1 – Bluffers Park Access Route ............................................................................... 81
Alternative 2 – Marine Access Route ......................................................................................... 82
Alternative 3 – Guild Inn Access Route...................................................................................... 83
Alternative 4 – Bellamy Ravine Access Route........................................................................... 83
Alternative 5 – Top Dumping....................................................................................................... 84
10.0
PREFERRED ACCESS ROUTE ............................................................................................... 84
10.1
Public Comments on Preferred Construction Access Route .................................................. 84
10.1.1
Public Accessibility .................................................................................................................... 85
10.1.2
Guildwood Community Public Safety........................................................................................ 85
10.1.3
Disturbance to Existing Vegetation and Wildlife........................................................................ 86
10.1.4
Noise.......................................................................................................................................... 86
10.1.5
Vibration..................................................................................................................................... 87
10.1.6
Dust............................................................................................................................................ 87
11.0
SUMMARY OF PUBLIC CONSULTATION ............................................................................... 87
11.1
Role of the Community Liaison Committee............................................................................... 87
11.2
Public Notifications and Consultation ....................................................................................... 88
11.2.1
Notice of Intent........................................................................................................................... 89
11.2.2
Community Liaison Committee Meeting #1 ............................................................................. 89
11.2.3
Community Liaison Committee Meeting #2 ............................................................................. 90
11.2.4
Public Meeting #1 ..................................................................................................................... 91
11.2.5
Public Meeting #2 ..................................................................................................................... 91
11.2.6
Meetings with the Guildwood Village Community Association ................................................. 93
11.2.7
Notice of Filing........................................................................................................................... 93
11.2.8
Notice of Project Approval......................................................................................................... 93
12.0
MONITORING PROGRAM ........................................................................................................... 93
13.0
REFERENCES ......................................................................................................................... 94
VI
LIST OF FIGURES AND TABLES
FIGURE 1. GENERAL STUDY AREA. . .................................................................................................................. 1
FIGURE 2. CLASS ENVIRONMENTAL ASSESSMENT PLANNING AND DESIGN PROCESS.. ............................................... 3
FIGURE 3. OBLIQUE AERIAL PHOTO OF THE STUDY AREA. .................................................................................... 4
FIGURE 4. OBLIQUE AERIAL PHOTO OF THE STUDY AREA. .................................................................................... 4
FIGURE 5. VIEW OF BLUFF CREST AT 10 MEADOWCLIFFE DRIVE. .......................................................................... 5
FIGURE 6. GEOLOGICAL FORMATIONS FOUND AT THE PROJECT SITE. ...................................................................... 17
FIGURE 7. AREAS OF NATURAL AND SCIENTIFIC INTEREST. ................................................................................ 19
FIGURE 8. SCARBOROUGH BLUFFS SEQUENCE ESA #123. ............................................................................. 20
FIGURE 9. LOCATION OF STORM SEWER OUTFALL WITHIN BELLAMY RAVINE.
..................................................... 22
FIGURE 10. LAKE ONTARIO WATER LEVELS FOR 2008-2009. ............................................................................ 23
FIGURE 11. LITTORAL CELL BOUNDARIES LOCATED ON THE TORONTO WATERFRONT.
.......................................... 25
FIGURE 12. BOUNDARIES OF CLIFFCREST COMMUNITY.
................................................................................... 45
FIGURE 13. THE "DO - NOTHING" ALTERNATIVE DEPICTS THE POTENTIAL POSITION OF THE BLUFF TOE . .................... 49
FIGURE 14. PRELIMINARY CONCEPT 1A - HEADLAND BEACH. MEADOWCLIFFE DRIVE ONLY. ..................................... 50
FIGURE 15. PRELIMINARY CONCEPT 1B - HEADLAND BEACH, BLUFF PROTECTION OVER FULL PROJECT SITE. ............. 51
FIGURE 16. PRELIMINARY CONCEPT 2A & 2B – GROYNE/HEADLAND BEACH. . ........................................................ 52
FIGURE 17. PRELIMINARY CONCEPT 3 - BREAKWATER + COBBLE BEACH . .............................................................. 53
FIGURE 18. PRELIMINARY CONCEPT 4A, 4B + 4C – HEADLAND/GROYNE + ADDITIONAL PROTECTION. . .................... 55
FIGURE 19. RESULTS OF THE EVALUATION CRITERIA BY CATEGORY AS RANKED BY CLC MEMBERS …………... ......... 61
FIGURE 20. LTSSC POSITION IN RELATION TO PROPERTIES 1, 2 AND 10 MEADOWCLIFFE DRIVE. .............................. 66
FIGURE 21. ALTERNATIVE 1 – BLUFFERS PARK ACCESS ROUTE. ....................................................................... 77
FIGURE 22. ALTERNATIVE 2 – MARINE ACCESS ROUTE. . .................................................................................. 78
FIGURE 23. ALTERNATIVE 3 – GUILD INN ACCESS ROUTE.
. ............................................................................. 79
FIGURE 24. ALTERNATIVE 4 – BELLAMY RAVINE ACCESS ROUTE.
. .................................................................. 80
TABLE 1. AIR QUALITY READINGS FOR EASTERN TORONTO (JULY 17, 2009). ......................................................... 20
TABLE 2. AIR QUALITY READINGS FOR EASTERN TORONTO (AUGUST 20, 2009). .................................................... 21
TABLE 3. LAKE ONTARIO WATER LEVELS. ............................................................................................................ 23
TABLE 4. WATER LEVEL AND SET UP SUMMARY FOR LAKE ONTARIO AT TORONTO................................................... 24
TABLE 5. SEDIMENT SUPPLY RATES. ................................................................................................................... 26
TABLE 6. HISTORICAL WATER QUALITY MEASUREMENTS....................................................................................... 27
TABLE 7. SEDIMENT QUALITY RESULTS. .............................................................................................................. 29
TABLE 8. FISH SPECIES COLLECTED ON THE SCARBOROUGH SHORELINE............................................................... 31
TABLE 9. ADDITIONAL FISH SPECIES COLLECTED ON THE SCARBOROUGH SHORELINE............................................. 32
TABLE 10. FLORA SPECIES OF CONCERN. ........................................................................................................... 35
TABLE 11. BIRD SPECIES OBSERVED ON THE SCARBOROUGH SHORELINE.............................................................. 36
TABLE 12. RESULTS OF EVALUATION PRELIMINARY CONCEPTS .............................................................................. 57
TABLE 13. RANKINGS OF PROPOSED EVALUATION CRITERIA.................................................................................. 60
TABLE 14. DETAILED ENVIRONMENTAL ANALYSIS OF THE PREFERRED ALTERNATIVE. ............................................... 68
LIST OF APPENDICES
APPENDIX A
EXISTING CONDITIONS
APPENDIX B
DESIGN OF PREFERRED ALTERNATIVE
APPENDIX C
PUBLIC CONSULTATION DOCUMENTATION
APPENDIX D
DOCUMENTATION IN SUPPORT OF PROPOSED CONSTRUCTION ACCESS ROUTE
VII
1.0
INTRODUCTION
Toronto and Region Conservation Authority (TRCA) is proposing to carry out remedial erosion
control work along a portion of the Lake Ontario shoreline, known here after as the
Meadowcliffe Sector. The Meadowcliffe Sector is located at the base of the Scarborough Bluffs
from Bellamy Ravine, also known as Gates Gully, westerly to East Beach at Bluffers Park in the
City of Toronto (Figure 1). The study limits stretches approximately 1,400 metres (m) along the
shoreline. The main area of erosion is concentrated along 600 m of the bluffs directly below
Meadowcliffe Drive, approximately 57 m high with an average inclination of about 1.2:1
horizontal:vertical (h:v), where the shoreline is in direct contact with the bluff toe. The slope
face is generally bare with some localized areas of sparse vegetation growing on the upper
slope.
Figure 1. General Study Area.
Source: TRCA, 2009.
The following Environmental Study Report (ESR) has been prepared as documentation of the
decision-making approach exercised in determining the preferred measure for the proposed
remedial work, and to establish that there are no negative impacts or outstanding concerns
held by TRCA or reviewers associated with the proposed work.
1.1
Relationship of the Undertaking to the Environmental Assessment Act
TRCA is defined as a public body in Section 3 of Regulation 334/90 in the Environmental
Assessment Act (R.S.O.) 1990, and as such, must conduct its remedial flood and erosion
control projects in accordance with said Act.
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Recognizing that common elements exist in addressing flood and erosion problems, a
coordinated approach to environmental assessments was developed by Conservation Ontario
for all Conservation Authorities (CAs) known as the Class Environmental Assessment for
Remedial and Erosion Control Projects (Class EA). According to the Class EA document:
“Remedial Flood and Erosion Control Projects refer to those projects
undertaken by Conservation Authorities, which are required to protect
human life and property, in previously developed areas, from an
impending flood or erosion problem. Such projects do not include
works which facilitate or anticipate development. Major flood and
erosion control undertakings which do not suit this definition, such as
multipurpose projects, lie outside the limits of this Class and require an
Individual Environmental Assessment” (Conservation Ontario, 2002).
Twenty years of experience has demonstrated that using the Class EA approach for dealing
with flood and erosion control projects is an effective way of complying with the Act
requirements. Approval of the Class EA allows CAs to carry out these types of projects without
applying for formal approval under the Act, on the condition that all other necessary federal
and provincial approvals are obtained. A chart illustrating the key steps of the Class EA
planning and design process is shown in Figure 2.
In addition to the Class EA process, TRCA recognizes that the project will require an
environmental screening under the Canadian Environmental Assessment Act (CEAA). CEAA
will be triggered in response to the potential environmental impacts that the project will
produce pursuant to subsection 35(2) under the federal Fisheries Act and section 5(1) of the
federal Navigable Waters Protection Act. Once the Class EA process is complete, the
appropriate provincial and federal departments will be contacted: Fisheries and Oceans
Canada (DFO), Environment Canada, Heritage Canada, Health Canada, Transport Canada and
Natural Resources Canada. TRCA will prepare a Project Description for review by the selected
Responsible Authority and the Canadian Environmental Assessment Agency to initiate the
scope of the project, the scope of the assessment, and the scope of factors to be considered.
TRCA will also contact other potentially interested agencies to ensure that all considerations
are made in relation to the proposed undertaking.
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March 2010
Figure 2. Class Environmental Assessment Planning and Design Process. Source: Conservation Ontario,
2002.
1.2
Purpose of the Undertaking
The objective of the Meadowcliffe Drive Erosion Control Project (the project), is to protect
human life and property from the hazards of erosion and slope instability at the project site by
providing long-term, low maintenance protection which is compatible with the surrounding
physical, biological, social and cultural environment.
1.3
Site Description
The current project limits is located along the base of the Scarborough Bluffs and comprises of
approximately 1,400 metres (m) of shoreline extending from Bellamy Ravine, also known as
Gates Gully, westerly to East Beach at Bluffers Park. Roughly half of the tableland in this sector
is dedicated greenspace within Cudia Park, west of Meadowcliffe Drive and east of Lakehill
Crescent. The remaining tableland at Meadowcliffe Drive and Lakehill Crescent is privately
owned with 16 residential properties backing onto the bluffs. The 600 m of bluffs directly below
Meadowcliffe Drive are approximately 57 m high with an average inclination of about 1.2:1 h:v,
where the shoreline is in direct contact with the bluff toe. The upper 8 to 10 m of the bluffs has
an inclination of 0.7:1 to 1.4:1 h:v and consists of permeable subsoil layers that promote
formation of temporary perched groundwater following rainfall or snow melt events. The slope
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March 2010
face is generally bare with some localized areas of sparse vegetation growing on the upper
slope. Representative photographs of the study area are shown in Figure 3 to Figure 5.
Figure 3. Oblique aerial photo of the study area.
Source: TRCA, 2006.
Figure 4. Oblique aerial photo of the study area.
Source: TRCA, 2006.
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Figure 5. View of bluff crest at 10 Meadowcliffe Drive.
1.4
Source: TRCA, 2007.
General Description of the Undertaking
There are four situations in which remedial flood and erosion control projects may be
undertaken within the Class EA:
I) Riverine Flooding
II) Riverine and Valley Slope Erosion
III) Shoreline Flooding
IV) Shoreline Erosion
The primary objective of the project is to provide long-term protection against (IV) shoreline
erosion. Alternative remedial measures to address this problem situation include:
• Reducing wave energy and enhancing natural processes;
• Protecting the shore from wave energy; and
• Stabilizing slopes through drainage or grading improvements.
Secondary objectives include the protection of existing land uses, improved aesthetics, and
improved aquatic and terrestrial habitat. The project will examine a number of alternatives to
achieve the primary and secondary objectives outlined in the Class EA document, including:
• Headland beach
• Headland beach and boulder berm
• Offshore breakwaters plus headland beach
• Groyne retained sand beach
In accordance with the Class EA planning process, a full range of alternatives must be
developed, including both traditional and innovative approaches. The type and range of
alternatives developed, such as the ones listed above, will vary by project as they are based on
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March 2010
the nature, cause and extent of the problem, and must be tailored to the individual
characteristics of each site.
The decision making approach used in the selection of the preferred remedial action is
documented in detail in Section 5.0.
In determining the preferred measure to remediate the erosion and slope instability problem,
two major factors were considered: risk to structure(s); and the cause of the hazard.
According to TRCA’s Design Criteria, potential risk to existing structures is deemed to be the
most important factor and accordingly is given more weight than the physical and geological
condition associated with the cause of erosion and/or instability.
In all cases, the design of erosion control and slope stabilization works must provide protection
compatible with TRCA’s Design Criteria, which includes improvements to or enhancements of
aquatic and terrestrial habitat conditions through natural designs.
Based on the outcome of the Class EA process for this project, the proposed remedial action
(the undertaking) consists of a cobble beach retained by four headlands. The preferred
solution also considers the potential need for a buttress at the base of the bluffs at the east end
of the shoreline sector to reduce slope recession.
The decision-making approach used in selecting this as the preferred remedial action is
documented in detail in Section 5.0 of this report. The proposed undertaking meets all TRCA
planning and policy objectives, and satisfies the needs and concerns of the affected property
owners and general public.
1.5
Rationale for the Undertaking
For several decades TRCA has monitored the rate of erosion along the crest of the
Scarborough Bluffs in relation to permanent structures (e.g. residential dwellings), mainly on
private residential properties. The acceleration of the erosion rate observed along the
Meadowcliffe Sector through TRCA’s annual erosion monitoring, prompted TRCA to retain a
geotechnical consulting firm to conduct a review of slope stability and erosion in 2006. The
results of this geotechnical review determined that the upper 30 m of the bluff face is expected
to recede to a stable inclination of 1.5:1 (h:v), while the lower section of the bluff is expected to
reach a shallower inclination of 2.5:1 (h:v) in the long-term. The report also notes that the longterm stable slope crest (LTSSC) is influenced by the position of slope toe which is subject to
recession caused by active wave erosion of the slope toe. The LTSSC is the position on the
tableland adjacent to the subject slope that represents the application of setbacks for both the
toe erosion allowance and slope stability components. Based on these analyses, Terraprobe
calculated the stability setbacks from the existing slope crest, assuming that toe protection is in
place, and determined that three residential dwellings could become be at risk and affected by
slope instability and erosion in the long-term if stabilization and protection works were not
carried out.
Shoreplan’s analysis suggests that as the shoreline erodes the fillet beach located east of
Bluffers Park will continue its eastward growth, gradually protecting the toe of the bluffs as it
expands until the beach provides full protection against wave induced toe erosion. Based on
this prediction and an average recession of the bluff toe at a rate of 1.2 m per year, it estimated
that numerous residential properties on both Meadowcliffe Drive and Lakehill Crescent, as
shown in Figure 13, will be impacted by erosion and slope recession.
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March 2010
TRCA remedial erosion control works are carried out within the context of a comprehensive
plan which balances the various resource management and ecological benefits of these works
with public access and related issues, and are further analyzed on the basis of financial
cost/benefit. In accordance with the Class EA process, it must also be demonstrated that the
proposed action falls within the scope of TRCAs watershed plan and is consistent with policies
and appropriate programs within which the proposed project may be considered to be a part.
The primary properties affected by slope instability and erosion within the study area include
private residences. Due to the location of these properties and their view of Lake Ontario,
many of these properties have considerable market value. There are twelve (12) properties
along Meadowcliffe Drive, as well as several homes on Lakehill Crescent that are potentially
impacted due to long-term issues arising from erosion and slope instability. Current market
value of these homes is estimated in the millions. The residence known as “Fool’s Paradise”
located at 1 Meadowcliffe Drive, designated as a heritage site by Ontario Heritage Trust, is also
at risk. It would be difficult to put a monetary value on this property, as it was donated by Doris
McCarthy, a Canadian artist, to be used as an area for heritage and artist activities.
Prior to making a decision to proceed with a remedial action at this location TRCA had to
consider the impact of a “Do-Nothing” approach, as well as the feasibility of employing another
Conservation Authority program such as land acquisition. Considering the potential risk to life
and property that would result if a “Do-Nothing” approach was taken as well as the potential
cost to purchase the affected properties, TRCA made the determination to proceed with a
Class Environmental Assessment for Remedial and Erosion Control Projects.
2.0
BACKGROUND
2.1
History of the Problem
TRCA staff has been monitoring erosion rates on Meadowcliffe Drive since 1985 at the request
of several homeowners who expressed concern over the loss of property and the potential
long-term risk to their homes.
In 1996, TRCA prepared the Integrated Shoreline Management Plan (ISMP) to provide a more
detailed understanding of the shoreline ecosystem within the boundaries of Tommy Thompson
Park and Frenchman’s Bay, and to provide the necessary framework for TRCA and local
municipalities to establish priorities for future initiatives and for evaluating site-specific
shoreline works, protection of natural features, lakefilling, habitat protection and regeneration,
private development and public recreation activities.
The ISMP states that the Meadowcliffe Drive shoreline should remain in a natural state because
it represents one of the few unprotected and natural shores of the Scarborough Bluffs. It is
recommended in the ISMP that nearshore armouring with boulder placement be considered on
an experimental basis in an attempt to restore the condition of the shore prior to the 1800s,
improve informal access along the shoreline and improve local fish habitat. It was noted,
however, that the change to the shoreline would be a very gradual one and that erosion would
not be eliminated. Based on the recommendations in the ISMP, TRCA continued to monitor
the rate of erosion along Meadowcliffe Drive and did not pursue any shoreline stabilization
options.
7
March 2010
In 2001, after a period of active erosion, TRCA commissioned Terraprobe Limited to carry out a
geotechnical review of slope stability and erosion along the Lake Ontario shoreline immediately
below Meadowcliffe Drive. This study included a review of historical air photos, soil and
groundwater conditions, erosion processes and rates, a detailed slope stability analysis,
coastal engineering review and recommended erosion protection.
In their final report dated November 27, 2001, Terraprobe provided calculations of slope crest
erosion rates between 1991 and 2001 and determined that localized crest loss ranged from 6
to 12 metres at the west part of the study area, to about 2 to 3.5 metres at the east part of the
study area. Noting that the erosion was primarily the result of toe erosion by wave action and
surface run-off flowing over the slope crest, the following recommendations were made:
•
•
•
•
•
A significant upgrade of the stormwater collection system along the Meadowclife Drive
right-of-way;
Connection of existing roof eavestroughs to the street storm sewer;
Construction of small earth berms along the slope crest;
Placing boulders near the shore on an experimental basis, as recommended in the
ISMP; and
Planting/seeding along the gullies and on bare slope areas.
Terraprobe also recommended further studies including:
•
•
Continued monitoring of the slope crest on an annual or bi-annual basis; and
A stormwater management assessment of the area to determine the quantities of
surface runoff over the slope crest.
Following the release of the 2001 Terraprobe report, staff continued to monitor the slope crest
on an annual basis and the City of Toronto commissioned Winter Burnside to carry out a storm
drainage study for the Meadowcliffe Drive area. The final Winter Burnside report in 2002
resulted in several upgrades being carried out by the City of Toronto in 2004. It is understood
that these improvements included depression storage, enhanced ditches and storm sewers,
and a landscaping component.
In the spring of 2005, slides occurred along several sections of the Scarborough Bluffs.
Numerous homeowners on Meadowcliffe Drive expressed concern to Councillor Ashton’s office
over the amount of property lost to erosion in a single year and requested that remedial action
be taken. In response to the residents’ concerns, TRCA commissioned Terraprobe to reassess the site and slope conditions and compare these findings to their 2001 report, and to
provide recommendations on slope and shoreline stabilization works.
As part of this study, detailed measurements of the slope crest position were taken relative to
the existing structures and features at each of the 12 residential properties. Based on
Terraprobe’s measurements, slope crest recession rates ranged from 0.04 to 2.14 m per year
between 2000 and 2005. Toe erosion rates were inferred through a comparison of the
shoreline positions available on maps of air photos from 1980, 1991, 2002 and 2005. As a
general trend, localized deepening of the lakebed topography was also noted in the order of
0.2 to 0.3 m and may be attributed to ongoing erosion and recession of the toe. It was also
noted that the potential for waves to uprush and erode the slope toe increases with the
deepening of the lakebed.
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March 2010
Based on the 2005 slope stability analysis, the LTSSC is projected to move inland by
approximately 48 m from the 2005 slope crest. This LTSSC was determined with the
assumption that there would be no further erosion at the toe of the bluffs. It should be noted
however, that wave action continues to erode the exposed toe, and the LTSSC will continue to
move further inland as the toe continues to recede. The final report, dated April 26, 2006,
illustrates the long-term risk to the Meadowcliffe properties by providing minimum distance
from each property to the LTSSC, which concluded at least 5 houses are between 0 and 10 m
from the LTSSC and several others are within 25 metres of this projected slope crest. Also
within the LTSSC is the easternmost portion of the roadway and stormwater collection drains.
Based on the significant recession of the slope toe and respective recession of the LTSSC,
Terraprobe strongly recommended that shoreline works be implemented.
In May 2006, staff attended a public meeting hosted by Councillor Ashton for the Meadowcliffe
Drive residents. The purpose of the meeting was to present the findings in the 2006
Terraprobe report and to give the property owners an opportunity to voice their concerns in an
open forum. At the meeting the public requested that action be taken to provide long-term
protection for the shoreline and TRCA received a letter shortly thereafter from Councillor Ashton
in support of this initiative.
Based on the significant change in recession rates, and the support of Councillor Brian Ashton
and the Meadowcliffe community for immediate action, TRCA received internal approval to
investigate a broader range of alternatives than described in the ISMP, and that these options
be evaluated through the Class EA process. The study area was expanded beyond
Meadowcliffe Drive to include all of the unprotected shoreline between Bellamy Ravine and the
East Beach at Bluffers Park in order to gain a thorough understanding of the coastal processes
affecting the site, and to ensure that the alternative options consider impacts to natural
heritage, public access and public safety.
2.2
Identification of Previous Studies
2.2.1
Geotechnical Reports
TRCA has also commissioned studies to develop a range of shoreline protection works that
could be used along the Meadowcliffe Sector. As a component of the Class EA, TRCA
developed a geotechnical assessment along the bluffs based on a review of the following
reports:
•
•
•
•
•
•
•
Geocon Inc. 1982. Erosion Control Study, Stage 2, Scarborough Bluffs.
Golder Associates Ltd. 1990. Subsurface Investigation, Meadowcliffe Drive Sewer
Works and Storm Sewer Outfall to Bellamy Ravine.
Geocon Inc. 1996. Slope Stability Study, Meadowcliffe Drive.
Terraprobe Ltd. 2001. Geotechnical Investigation and Slope Stability Assessment,
Meadowclife Drive.
Terraprobe Ltd. 2006. Geotechnical Review of Slope Stability and Erosion, Meadowclife
Drive, Scarborough Bluffs, Toronto.
Terraprobe Ltd. 2009. Geotechnical Review of Slope Stability and Erosion Stabilization
Options, Meadowclife Drive, Scarborough Bluffs, Toronto.
Winter Burnside. 2002. Meadowcliffe Drive Area Storm Drainage Study for City of
Toronto.
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March 2010
The assessment of the historical geotechnical reports helped determine the LTSSC, the most
recent 2005 slope toe position indicated the residential dwellings at Nos. 2, 10 and 42,
including a shed at the residential property No. 10 are all within the LTSSC. These dwellings
have the potential to become unsafe and affected by the slope instability and erosion. As a
result the need for a Class Environmental Assessment to examine shoreline protection works
along the Meadowcliffe Drive Sector was identified.
Copies of these technical reports are available for review at TRCA, 1 Eastville Avenue, Toronto.
2.2.2
Planning Documents
The study area has received extensive scrutiny at all levels of government as part of the
Toronto Waterfront planning process. In developing the range of alternatives for evaluation
under the Class EA guidelines, TRCA utilized and incorporated many of the planning
recommendations from the municipal, provincial and federal governments.
Metropolitan Waterfront Plan (1994)
In 1994, a revised vision of the Toronto Waterfront was developed by the City of Toronto to
achieve a waterfront that is “healthy, vibrant and publicly accessible, through responsible
stewardship, and strong partnerships between government and the community”. The Plan laid
out many policies, some of which are general in nature and others that specifically refer to the
Scarborough bluffs. A summary of the most pertinent policies in this plan are provided below:
3) to undertake the protection and enhancement of the following
significant natural areas in cooperation with the MTRCA, area
municipalities, other appropriate agencies and the community:
a) terrestrial habitats within:
ii) Scarborough Bluff area;
22) to oppose the creation of additional land or permanent
structures in Lake Ontario through lakefilling or dredging,
except for recreational or essential public works which comply
with the other applicable policies of the Plan and that both
demonstrably contribute to the healthy functioning of coastal
and biological processes and provide public benefits as
determined by Council in consultation with other responsible
agencies by
a) improving water quality;
b) enhancing or creating aquatic habitat; and
c) providing public access to the water’s edge.
24) to maintain and restore within the Waterfront Environmental
Impact Zone (WEIZ) a diversity of terrestrial and aquatic habitats
and connecting links between habitats as part of a
comprehensive strategy that includes:
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March 2010
a) the conservation, enhancement and management of
terrestrial ecosystems on unstable slopes and floodsusceptible, where feasible;
b) the use of natural techniques for remediating problems
associated with hazard lands, where feasible;
c) initiatives to establish aquatic habitats where such
initiatives do not negatively alter the pattern of coastal
processes; and
d) the regulation by respective levels of government of all
activities that alter the land form or lakebed including
excavations, dredging and the placement of fill.
25) to support the development and administration of a Shoreline
Management Plan for the Metropolitan Waterfront by the
MTRCA in cooperation with other public agencies.
68) to protect and enhance the significance of the Scarborough
Bluffs area by:
a) allowing natural processes, such as regeneration and
erosion, to occur where feasible.
TRCA is committed to the City of Toronto’s vision of a healthy waterfront. TRCA will work to
ensure that these policies are considered throughout the planning, study and implementation
phases of the Meadowcliffe Drive Erosion Control Project.
Royal Commission on the Future of the Toronto Waterfront (1990)
In 1988, the Royal Commission on the future of the Toronto Waterfront was initiated as a
federal inquiry to:
“Make recommendations regarding the future of the Toronto Waterfront,
and to seek the Concurrence of affected authorities in such
recommendations, in order to ensure that, in the public interest, federal
lands and jurisdiction serve to enhance the physical, environmental,
legislative and administrative context governing the use, enjoyment and
development of the Toronto Waterfront and related lands” (Royal
Commission, 1990).
Recommendations were based on nine guiding principles for the future of Toronto Waterfront:
clean, green, usable, diverse, open, accessible, connected, affordable, and attractive.
Lake Ontario Greenway Strategy (1995)
The Lake Ontario Greenway Strategy was developed by the Waterfront Regeneration Trust in
fulfillment of its mandate to coordinate the programs and policies of the Province and agencies
related to the waterfront, and to facilitate the establishment of a waterfront trail. The vision the
Strategy calls for a waterfront that is clean, green, accessible, connected, open, usable,
diverse, affordable and attractive. To achieve this vision, the Strategy summarizes a number of
goals and objectives that include:
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March 2010
1) Protect the physical, natural and cultural attributes associated with the
Lake Ontario Greenway;
2) Identify restoration needs and methods and encourage landowners,
communities and agencies to undertake regeneration activities.
3) Promote greater awareness and understanding and recreational use of
the waterfront and encourage community pride and participation in its
regeneration.
4) Promote economic activities and employment on the waterfront that are
compatible with other Greenway objectives.
5) Foster cooperation in cost-effective public and private initiatives by
reducing jurisdictional gridlock, sharing resources, and coordinating
waterfront activities.
The Meadowcliffe Drive Erosion Control Project incorporates the objectives of the Lake Ontario
Greenway Strategy to ensure that all alternatives comply with provincial interests and policies.
Integrated Shoreline Management Plan: Tommy Thompson Park to Frenchman’s Bay (1996)
The Integrated Shoreline Management Plan (ISMP) was developed by TRCA following a
recommendation put forth in the Lake Ontario Greenway Strategy in 1995. The goal of the
ISMP is:
“…to provide an ecosystem-based framework to ensure that shoreline
management activities result in a clean, green, accessible, diverse,
connected, open, affordable, attractive and useable waterfront from
Tommy Thompson Park to Frenchman’s Bay” (TRCA, 1996).
As previously noted, the ISMP reported that the Meadowcliffe Drive shoreline should remain in
a natural state because it represents one of the few unprotected and natural shores of the
Scarborough Bluffs. It is recommended in the ISMP that nearshore armouring with boulder
placement be considered on an experimental basis in an attempt to restore the condition of the
shore prior to the 1800s, improve informal access along the shoreline and improve local fish
habitat. It was noted, however, that the change to the shoreline would be a very gradual one
and that erosion would not be eliminated. Based on the recommendations in the ISMP, TRCA
continued to monitor the rate of erosion along Meadowcliffe Drive and did not pursue any
shoreline stabilization options.
2.2.3
Aquatic and Terrestrial Habitat Reports
The aquatic and terrestrial conditions along the Toronto Waterfront have undergone intensive
scrutiny during the last thirty years. The collapse of native fish stocks, turbid, odorous and
polluted water, reductions in waterfowl populations, sediment contamination, a scarcity of
public waterfront access, massive algal blooms, increases in invasive wildlife and plant
species, and large-scale decline in fish populations are demonstrative of the effects of
urbanization.
During the mid-1980s, studies were conducted by the Toronto Remedial Action Plan (RAP) to
specifically identify sources of degradation along the Toronto Waterfront and to provide targets
and recommendations to improve these conditions. Since the 1980s, the Toronto RAP has
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March 2010
continued to fund projects aimed to improve the Toronto Waterfront, continued to monitor lake
health to quantify improvements in overall habitat quality and assess the success of
remediation efforts.
This Class EA incorporates a number of studies compiled over the last thirty years in order to
provide a temporal understanding of the environmental conditions along the Meadowcliffe
Drive Sector. These reports include:
• Environment Canada, Ministry of the Environment, Ministry of Natural Resources,
Toronto and Region Conservation Authority.1989. Metro Toronto and Region
Remedial Action Plan. Stage 1. Environmental Conditions and Problem Definition.
• Environment Canada, Canadian Wildlife Service, Blokpoel, H. and Tessier, G.D.
1991. Distribution and Abundance of Colonial Waterbirds Nesting in the Canadian
Portions of the Lower Great Lakes System in 1990, Technical Report Series No. 117.
• Metropolitan Toronto Planning Department, Research and Special Studies
Department Division. 1995. State of the Environment Report: Metropolitan Toronto.
• Ministry of the Environment.1985. Historical Development and Quality of the Toronto
Waterfront Sediments - Part I.
• Ministry of Natural Resources (MNR). 1974. Operation Doorstop Angling:
Metropolitan Toronto Fishery Project Report - Volume One.
• Ministry of Natural Resources (MNR). 1989. Fish Community and Aquatic Habitat of
the Toronto Waterfront.
• Ministry of Natural Resources. 1994. 1989 - 1993 Toronto Waterfront Fish
Communities: Summary and Assessment.
• Shoreline Management Work Group for the Waterfront Regeneration Trust. 1996.
Shore Management Opportunities for the Lake Ontario Greenway.
• Toronto and Region Conservation Authority (TRCA). 1996. Integrated Shoreline
Management Plan: Tommy Thompson Park to Frenchman’s Bay.
• Toronto and Region Conservation Authority (TRCA). 2000. Toronto Waterfront
Fisheries Communities.
• Toronto and Region Conservation Authority (TRCA). 1982. Environmentally
Significant Areas Study.
• Waterfront Regeneration Trust. 1987. Toronto Eastern Waterfront Summary: A Report
for the Toronto Remedial Action Plan Work Team. Beak Consultants Ltd.
• Waterfront Regeneration Trust. 1995. Lake Ontario Greenway Strategy.
• Waterfront Regeneration Trust. 1995. Lake Ontario Greenway Strategy, Next Steps.
• Waterfront Regeneration Trust. 2002. Clean Waters, Healthy Habitats: Progress Report
2001 Technical Edition - Toronto and Region Remedial Action Plan.
Terrestrial and aquatic data was obtained by TRCA. Data from these inventories are referenced
in this report where applicable.
2.2.4
Socioeconomic and Cultural Heritage Studies
The following sources of information were used to define the socioeconomic conditions and
cultural heritage resources for the Study Area:
• City of Toronto website. 2001 and 2006. Cliffcrest Neighbourhood Profile.
(www.toronto. ca/demographics /cns _ profiles/cns123.htm).
• Guildwood Village Community Association (GVCA) website. 2009. (www.guildwood.
on.ca).
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March 2010
• Ontario Heritage Trust website. 2009. Provincial Plaque Unveiling Commemorates
Fool’s Paradise – Home and Studio of Renowned Artist Doris McCarthy.
(www.heritagefdn.on.ca/ userfiles/ HTML/nts_1_8214_1.html).
• Roots, B., Chant, D.A. and Heidenreich, C.1999. Special Places: The Changing
Ecosystems of the Toronto Region.
• Toronto Neighbourhoods website. 2009. Cliffcrest. (www.torontoneighbourhoods.
net/regions/ scarborough).
• Toronto Transit Commission (TTC) website. 2009. Bus Routes, 86 Scarborough.
(www.ttc.on.ca).
• Waterfront Regeneration Trust. 1995. Lake Ontario Waterfront Experiences.
• Waterfront Regeneration Trust. 1995. The Waterfront Trail.
2.3
Justification of Conservation Authority Involvement
TRCA has a mandate to carry out remedial erosion control works as set out in Section 20 of the
Conservation Authorities Act (R.S.O. 1990):
“The objects of an authority are to establish and undertake, in the area
which it has jurisdiction, a program designed to further the
conservation, restoration, development and management of natural
resources other than gas, oil, coal and minerals (R.S.O. 1990, C.27,
s.20).”
As part of this broad mandate, CAs are considered to have prime responsibility over water
management in terms of water quantity and related hazards through administrative and
regulatory powers. In the 1980 Watershed Plan, TRCA developed and implemented its Erosion
and Sediment Control Program (ESCP) with two major directions:
“To minimize the aggravation or creation of erosion or sediment
problems as a result of new development, and to rectify existing
problems through protective works” (TRCA, 1980).
These directions are categorized as either preventative, or protective, respectively. The project
falls under the protection component of the ESCP, which is designed to protect lives and
minimize loss of property through the construction of suitable remedial works. Through annual
capital funding from the City of Toronto, TRCA is able to implement a program or major
remedial works for shoreline protection and slope stabilization throughout the watersheds
within the City of Toronto. The goal of TRCA through this project is to prevent, eliminate or
reduce the risk of hazard to life and property, and to protect and enhance the natural attributes
along the Lake Ontario shoreline and the primary river valleys within Toronto.
The results of the geotechnical assessment carried out by Terraprobe (2006) as described in
Section 2.2 indicates that erosion and slope instability will likely continue at the site, resulting
in the further loss of property at the top of the crest, which will eventually affect the residential
dwellings located on Meadowcliffe Drive if remedial action is not taken.
3.0
BASELINE ENVIRONMENTAL INVENTORY
Once the determination has been made that remedial works are warranted at a given site, a
baseline inventory is prepared. TRCA has developed the following baseline inventory of the
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March 2010
existing conditions of the Meadowcliffe Drive shoreline and surrounding environments. The
baseline environmental inventory provides the information required to evaluate the alternative
methods, and the forms of the baseline from which the preferred alternative will be compared
to determine its effectiveness, as well as its environmental impact.
The inventory involves the examination and documentation of:
•
•
•
•
the erosion problem;
existing site conditions, including physical, biological, cultural and socioeconomic
characteristics;
engineering/technical aspects to be considered; and
previous protective measures that have been implemented within the study area.
This baseline environmental inventory takes into consideration the directly and indirectly
affected environment. The indirect area affected by the project includes the entire littoral cell
and associated shorelands. This indirect area is referred to as the regional study area. The
area directly affected by the project is referred to as the study area or project site.
Baseline environmental data was collected from the following organizations due to their
specific expertise relevant to the regional and local study area:
•
•
•
•
•
•
•
•
Fisheries and Oceans Canada
Environment Canada
Ontario Ministry of Natural Resources
Ontario Ministry of the Environment
City of Toronto, Toronto Water
Waterfront Regeneration Trust
Toronto Field Naturalists
Toronto Ornithological Club
To assist with the review and expansion of the baseline inventory, as well as the design of the
preferred alternative, TRCA retained the services of the coastal engineering firm Shoreplan
Engineering Limited in 2006.
Several groups were contacted for their input into the inventory process. This included local
landowners, community groups such as the Guildwood Village Community Association,
Ontario Heritage Trust and local Councillor Brian Ashton (Cliffcrest Community) and Councillor
Paul Ainslie (Guildwood Community).
3.1
Location
The project site encompasses a section of Lake Ontario shoreline on the lakeward side of the
Scarborough Bluffs in the City of Toronto. This shoreline sector measures 1,400 m and is
located between the eastern beach of Bluffers Park and Bellamy Ravine (also known as Gates
Gully). The tableland adjacent to the shoreline includes dedicated greenspace, as well as 16
residential properties that back directly onto the bluffs.
Shoreline Reach:
Site Location:
Meadowcliffe Drive Sector
City of Toronto (former City of Scarborough)
Landowners:
TRCA, City of Toronto, Ontario Heritage Trust and private landowners all
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March 2010
Easting: 643613
Latitude: 43.72 N
UTM:
Topo Map No.:
Chart No.:
3.2
own the land, while the Ministry of Natural Resources owns the waterlot.
Northing: 48442809
Longitude: 79.23 W
432423
30M/11
2085
Existing Site Conditions
In accordance with the Class EA process, the broad definition of ‘environment’, as provided in
the Environmental Assessment Act, is applied to this section. The prepared environmental
description is “an inventory of elements for which a given project is likely to have an impact”
(Conservation Ontario, 1993). The inventory includes an evaluation of the presence and extent
of physical, biological, cultural, social, economic, and technical engineering elements
applicable to the study area.
3.2.1
Physical Environment
Unique Landforms
Next to Niagara Falls, the Scarborough Bluffs are considered by many as Ontario’s most
extraordinary natural feature, and have been studied in detail over the years due to the
geological insight they provide regarding past glacial events and climatic conditions. The
Scarborough Bluffs extend from Victoria Park Avenue to Highland Creek for approximately 20
kilometers (km) along the Toronto waterfront. Sedimentary deposition formed the
Scarborough Bluffs over the last 100,000 years. The bluffs range between 50 to 85 m above
lake level. The bluffs are internationally recognized as an important heritage resource that is
unique to Toronto.
The oldest and most dominant earth science feature is located near the base of the Bluffs. This
feature is composed of deltaic clays, silts, and sands, which are known as the Scarborough
Formation. It is divided into two separate layers: the overlying Scarborough Sand Formation
and the underlying Scarborough Clay Formation. The Scarborough Sand Formation
represents one of two aquifers systems along the Scarborough waterfront and the second
provides an impermeable layer underneath the Scarborough Sand (Eden and Eyles, 2002).
The Sunnybrook Till is the second major sedimentary formation making up the Scarborough
Bluffs, and is perched on top of the Scarborough Formation. This till deposit typically ranges
from 8 to 12 m in depth and is fine-grained in texture ranging from silt to silty-clay till. However,
some controversy exists as to the nature of the Sunnybrook formation as to whether it is
glaciolacustrian or strictly glacial in nature. Regardless, this formation acts as an aquatard with
high impermeability, low plasticity and a hard consistency.
Overlying the Sunnybrook Till is the Lower Leaside Till which consists of silty sand till with clay
and traces of gravel. This formation is very stiff to hard in consistency. It does, however provide
the second water table associated with the Scarborough Bluffs, located at the transition with
the more impermeable silts and clays located in the Sunnybrook Till.
A Middle Wisconsinan deposit is found at Cathedral Bluffs Park, which is represented by the
Thorncliffe Formation, Seminary Till, and Meadowcliffe Till. Further east at Cudia Park, Early
Wisconsinan and Middle Wisconsinan deposits are found beneath Late Wisconsinan Glacial
Lake Iroquois silts (Eden and Eyles, 2002). A glacial Lake Iroquois Bluff is also visible at Cudia
Park.
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March 2010
Figure 6. Geological formations found at the project site. Source: Eden and Eyles, 2002.
The average height of the bluffs along the Meadowcliffe Sector is approximately 57 m with an
average inclination of about 1.2:1 (horizontal: vertical). The slope face is generally bare of
vegetation with some localized areas of sparse vegetation on the upper edge of the slope. The
shoreline in this waterfront sector is located at toe of the bluff. TRCA staff has been monitoring
erosion rates on Meadowcliffe Drive since 1985 at the request of several homeowners who
have expressed concern over the loss of property and the potential long-term risk to their
homes.
To the east of the study area the Bellamy Ravine shoreline sector has a bluff face that is
vegetated with a mixture of herbaceous plants, shrubs, and deciduous trees. The deep stream
gullies are vegetated with a mixture of birch, poplar, cherry, maple, oak, hawthorne and willow
while the steep cliffs remain bare.
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March 2010
Existing Mineral / Aggregate Resource Extraction Industries
There were no existing mineral/aggregate resource extraction industries located within the
study area. However, from the 1830's to the First World War, the near shore area along the
Scarborough Bluffs was the site of a unique "stone hooking" industry. A “stone hooker” was a
shallow draft schooner that could work close to the shore, enabling crews to pick the large
shale slabs from the lakebed. Several men working together would use poles with bent forks
on the end to lift up a slab from the bottom and then maneuver it onto a floating raft towed
behind the ship. This material was used for ballast and would be later sold for construction
activities. By the 1830s, up to 43,000 tonnes of boulders were hooked on an annual basis.
Stone hooking is believed to have accelerated shoreline erosion along the Lake Ontario
shoreline. In 1857, a law was passed prohibiting stone hooking within 15 m of shore (TRCA,
2006).
Given the extent of the glacial deposits along the Scarborough Bluffs, the study area may be
viewed by the aggregate resource extraction industry as a potential resource location. The
Scarborough Bluffs however occupied by many well-established residential communities within
the City of Toronto and would therefore be unlikely location for aggregate resource extraction
within the foreseeable future.
Area of Natural and Scientific Interest – Earth Science (ANSI-ES)
The Ontario Ministry of Natural Resources (OMNR) selected three representative Areas of
Natural and Scientific Interest (ANSI) to depict the range of geological conditions along the
Scarborough Bluffs. To be classified as ANSIs, the following notable features have been
identified by the MNR:
“At their highest point, the Scarborough Bluffs rise 110 m above the
level of Lake Ontario. Located in the Borough of Scarborough, these
bluffs display the Pleistocene sequence of deposition in Ontario.
The Scarborough Bluffs are the highest and most continuous stretch of
shoreline cliffs in Site District 7 – 4. They also represent a unique
example of cliffs in Canada.” (OMNR, 1984).
Only one (1) of the three (3) areas to represent the geological history of the Scarborough Bluffs
is located in our study area, known as Cudia Park. This area demonstrates Early Wisconsinan,
Scarborough Formation and Sunnybrook Till, Middle Wisconsinan, Thorncliffe Formation (lower
and middle), Seminary Till, Meadowcliffe Till overlain by Late Wisconsinan, and Lake Iroquois
sediment (OMNR, 1998). The Scarborough Bluffs provide scientist with insight to North
America’s recent geologically history, and act as an important scenic, recreational and cultural
resource for the City of Toronto.
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March 2010
Figure 7. Areas of Natural and Scientific Interest.
Source: TRCA, 2009.
Specialty Crop Areas / Agricultural Lands or Production
The Meadowcliffe Drive, Cudia Park section of the Scarborough shoreline is located within an
urban, residential area. As such, no specialty crop areas or agricultural lands are involved in
the study area.
Niagara Escarpment / Oak Ridges Moraine
This section of shoreline is not located in the Niagara Escarpment or the Oak Ridges Moraine.
Environmentally Sensitive / Significant Areas (Physical)
The Environmental Sensitive Area (ESA) classified as ESA #123 (Scarborough Bluffs
Sequence) is located along the western portion of the project area from Cudia Park westward
(Figure 8). The Scarborough Bluffs Sequence ESA was selected to represent the geological
features found along the Scarborough Bluffs. To be classified as an ESA, Criterion 1 was
fulfilled.
The Scarborough Bluffs Sequence exhibits the most complete and interesting record of
Pleistocene geology in North America, if not the world. This Sequence shows evidence of
Seminary Till which has not been found to extend inland, and is one of the last areas in the
region where the Lake Iroquois shoreline (12,000 years B.P.) can be observed. This Sequence
also contains the Type Section for the Meadowcliffe Till (MTRCA, 1982).
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March 2010
Figure 8. Scarborough Bluffs Sequence ESA #123.
Source: TRCA, 2009.
Air Quality
The study area is located to the east of Toronto’s downtown core. The project area
experiences similar air quality conditions found throughout the Toronto region as a result of
urbanization and industrial development in Southern Ontario. Atmospheric pollutants that are
sampled on an hourly basis in the Toronto area include carbon monoxide (CO), nitrogen
dioxide (NO2), ground level ozone (O3), sulphur dioxide (SO2), and suspended particulates
and total reduced sulphur compounds. Typically, most air pollutants have decreased in
concentration or remained relatively stable since the late 1960’s (TRCA, 2004).
The Air Quality Index (AQI) is an indicator of air quality, based on hourly pollutant
measurements of some or all of the six most common air pollutants listed above and is used to
inform Toronto residents of the existing air quality and to provide health advisories when the
combined levels of the pollutants exceed certain levels of the index (MOE, 2009). If the air
quality value is below 32, the air quality is considered relatively good. If the AQI value is in the
range of 32 to 49 (moderate category), there may be some adverse effects on very sensitive
people. An index value in the 50 to 99 range (poor category), may have some short-term
adverse effects on the human or animal populations, or may cause significant damage to
vegetation and property. An AQI value of 100 or more (very poor category) may cause adverse
effects on a large proportion of those exposed (MOE, 2009).
Elevated air temperatures during the summer are related to increased air quality index
advisories and warnings may be issued for up to several weeks at a time depending on
weather conditions. Overall, air quality in Toronto is below National Ambient Air Quality
Objectives (MOE, 2009). Below are two examples of testing during spring and summer
months. The AQI ratings in July are much lower than the ratings in August and are typical to
what is found during these months.
Table 1. Air Quality Readings for Eastern Toronto (July 17, 2009).
Air Quality for TORONTO EAST
Date
Time
17-July-09
17-July-09
12:00 AM
1:00 AM
AQI
11
11
Cause
Ozone (O3)
Fine Particulate Matter (PM2.5)
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March 2010
Date
Time
17-July-09
17-July-09
17-July-09
17-July-09
17-July-09
17-July-09
17-July-09
17-July-09
17-July-09
17-July-09
17-July-09
2:00 AM
3:00 AM
4:00 AM
5:00 AM
6:00 AM
7:00 AM
8:00 AM
9:00 AM
10:00 AM
11:00 AM
12:00 PM
AQI
11
14
16
12
9
10
11
10
14
19
21
Cause
Ozone (O3)
Ozone (O3)
Ozone (O3)
Ozone (O3)
Ozone (O3)
Ozone (O3)
Ozone (O3)
Ozone (O3)
Source: MOE, 2009
Table 2. Air Quality Readings for Eastern Toronto (August 20, 2009).
Date
Time
20-Aug-09
20-Aug-09
20-Aug-09
20-Aug-09
20-Aug-09
20-Aug-09
20-Aug-09
20-Aug-09
20-Aug-09
20-Aug-09
20-Aug-09
20-Aug-09
20-Aug-09
12:00 AM
1:00 AM
2:00 AM
3:00 AM
4:00 AM
5:00 AM
6:00 AM
7:00 AM
8:00 AM
9:00 AM
10:00 AM
11:00 AM
12:00 PM
AQI
32
31
29
27
22
20
17
17
15
18
22
21
24
Cause
Ozone (O3)
Ozone (O3)
Ozone (O3)
Ozone (O3)
Ozone (O3)
Ozone (O3)
Ozone (O3)
Ozone (O3)
Ozone (O3)
Ozone (O3)
Source: MOE, 2009
At a local scale, no significant sources of air pollution exist within the immediate and
surrounding study area. No component of this project is anticipated to degrade air quality or be
influenced by local or regional sources of air pollution. Any impacts from machinery and/or
vehicles used as part of the construction phase will be temporary and minimal, and are
therefore not deemed to be significant.
Agriculture Tile or Surface Drains
There is a storm sewer outfall located north-east of the project site as shown in Figure 9. The
outfall is located within the Bellamy Ravine, south of Kingston Road. Run-off from the
surrounding area flows through this outfall down the ravine and directly into Lake Ontario. A
second storm sewer outfall is located further down the ravine, on the west side, which
discharges stormwater originating from the Meadowcliffe Drive area.
21
March 2010
Figure 9. Location of Storm Sewer Outfall within Bellamy Ravine.
Source: TRCA, 2006.
As previously noted the City of Toronto commissioned Winter Burnside to carry out a storm
drainage study for the Meadowcliffe Drive area. The final Winter Burnside report in 2002
resulted in several upgrades being carried out by the City of Toronto in 2004. It is understood
that these improvements included depression storage, enhanced ditches and storm sewers,
and a landscaping component.
Noise Levels and Vibrations
There are no noteworthy sources of noise or vibration located within this section of shoreline.
There may be occasional maintenance work along Meadowcliffe Drive or Lakehill Crescent.
Insignificant noise sources may consist of landscaping machinery along the bluffs, and
powerboats traveling offshore.
Water Flow Regime (High / Base and Low / Base)
Water levels in Lake Ontario have been regulated since 1960, however, regardless of controls,
the lake levels fluctuate on a short term, seasonal and long-term basis. Seasonally, changes of
about 0.5 m are expected. As depicted in the following graph, water levels generally peak in
June and are at their lowest in December. The sample locations for Lake Ontario are at Port
Weller, Toronto, Cobourg, Kingston, Rochester and Oswego (DFO, 2009). Although water
levels below chart datum are rare, the lowest monthly mean on record is approximately 73.8 m
(IGLD, 1985). Presently used datum for Lake Ontario is the International Great Lakes Datum
(IGLD), 1985. To convert IGLD 1985 datum to Geodetic Datum in the Toronto area, 0.13
metres must be added to the IGLD 1985 elevation.
22
March 2010
Figure 10 depicts recent variation of water levels on Lake Ontario, on a month-to-month and
year–to-year basis.
Figure 10. Lake Ontario Water Levels for 2008-2009.
Source: DFO, 2009.
Table 3. Lake Ontario Water Levels.
June 2009
Mean for month (preliminary data)
Mean for month last year
Mean for month, last ten years
Statistics for Period of Record
Maximum monthly mean/year
Mean for month
Minimum monthly mean /year
Probable mean for next month
Lake Ontario
75.16 m
75.19 m
75.07 m
1918-2008
75.76 m (1952)
75.04 m
74.19 m (1935)
75.08 m
Source: DFO, 2009.
NOTE: All water levels are expressed in meters using 1985 International Great Lake Water Datum
(IGLD85).
A summary of the water level variations and wind set up in this part of Lake Ontario is
presented in Table 4. The summary is based on a water level analysis completed by the
Ontario Ministry of Natural Resources (MNR, 1989).
23
March 2010
Table 4. Water Level and Set Up Summary for Lake Ontario at Toronto.
Return Period (years)
5
10
25
50
100
Instantaneous Water Level (metres, IGLD85)
75.40
75.49
75.60
75.67
75.74
Highest Annual Monthly Water Level (m IGLD)
75.2
75.3
75.4
75.5
75.6
Wind Set Up, Wind Surges (metres)
0.21
0.24
0.28
0.31
0.34
Source: MNR, 1989.
Existing Surface Drainage / Groundwater Seepage /Groundwater Recharge and Discharge
Zones
In 2001, after a period of active erosion, TRCA commissioned Terraprobe Limited to carry out a
geotechnical review of slope stability and erosion along the Lake Ontario shoreline immediately
below Meadowcliffe Drive. The final report concluded that the erosion was primarily the result
of toe erosion by wave action and surface run-off flowing over the slope crest. The firm
recommended the following storm drainage upgrades:
•
•
A significant upgrade of the stormwater collection system along the Meadowcliffe Drive
right-of-way; and
Connection of existing roof eavestroughs to the street storm sewer.
Terraprobe also recommended a more detailed stormwater management assessment of the
area be completed to determine the quantities of surface runoff over the slope crest.
As a result of the recommendations of the geotechnical report, the City of Toronto
commissioned Winter Burnside to carry out a storm drainage study for the Meadowcliffe Drive
area. The final Winter Burnside report in 2002 resulted in several upgrades being carried out
by the City of Toronto in 2004. It is understood that these improvements included depression
storage, enhanced ditches and storm sewers, and a landscaping component.
In 2006, Terraprobe was retained to review historical geotechnical investigations and complete
additional inspections on the Meadowcliffe area, the firm reported surface drainage from the
tablelands to the north of the project site to be directed into the stormwater outfall and
conveyance channel that discharges into Lake Ontario via Bellamy Ravine.
The groundwater was documented to be seeping at several elevations along the Meadowcliffe
sector of the bluffs. In particular, 3 to 4 metres (m) below the slope crest was reported to have
saturated bare patches, especially at 10, 16, 20, 30 and 32 Meadowcliffe Drive. Similar
saturated patches of the bare slope were observed at an approximate depth of 6 to 8 m and
again at 12 to 15 m (Terraprobe, 2006).
Littoral Drift / Sediment Transport
Littoral cells are sections of the shoreline, which are defined by sediment transport. Sediment
input and outflow are limited to the boundaries of the littoral cell. Defining the boundaries of
these cells is important as any actions taken on the shoreline within a littoral cell can have
consequences on other shoreline features located within the cell. As shown in Figure 11 the
project area is influenced by one (1) individual littoral cell.
24
March 2010
Figure 11. Littoral cell boundaries located on the Toronto waterfront.
Source: TRCA, 2004.
The project area is located within the nearshore sediment transport cells, which captures the
Lake Ontario shoreline from East Point Park in the east to Ashbridge’s Bay Park in the west.
Sediment transport characteristics at the site were investigated using numerical models. A bulk
energy sediment transport model was used to assess the stable orientation of a range of
cobble sizes for the design of artificial beaches. A detailed predictor sediment transport
program was used to assess the sediment transport pathways associated with the alongshore
transport of sand. This was done to provide information for the impact assessment of the
various concepts considered.
The net littoral drift direction at this site is from east to west. Atria (1993) calculated a sediment
budget for the shoreline from the R.C. Harris filtration plant to East Point. Modelling undertaken
by Shoreplan Engineering in 2007 determined that less than 5,000m3/yr of sediment is
transported to the site. The existing wave climate is capable of transporting the full sediment
supply past the site in water depths of approximately 2.5 metres below datum, and deeper.
East Point forms the eastern limit of the littoral cell containing the Meadowcliffe Drive site.
Table 5 shows the sediment supply rates that can be expected with the current level of
shoreline protection. It can be seen that of the approximately 25,000 m3/yr of sediment that is
supplied through shoreline erosion, 20,000 m3 of it comes from the Meadowcliffe Drive sector.
25
March 2010
Table 5. Sediment Supply Rates.
Shoreline Sector
%
Protected
3
Supply Rate (m /year)
(prior to protection)
1
3
Supply Rate (m /year)
(with protection)
East Point
0%
1,225
1,225
Grey Abbey
0%
910
910
Guildwood Parkway
75%
3,140
785
Guild Inn
100%
3,975
0
South Marine Drive
100%
4,095
0
Sylvan Ave
90%
9,800
980
Meadowcliffe
0%
20,010
20,010
43,155
23,910
Total
1 from Atria (1994)
On the basis of a sediment bypassing analysis, Baird (1994) concluded that Bluffers Park could
be considered to be a complete littoral barrier. Baird found that approximately 20 to 25% of the
incoming supply would bypass the eastern-most headland, but would likely either be deposited
in the entrance channel or deflected offshore at the western end of the park.
Wave Climate - Other Coastal Processes
Land and water meet along the coastline. The coast is shaped mainly by the action of the
waves, which reach the shore. Waves are created by the winds, which blow across the surface
of the water. Friction results in the transfer of energy from the wind to the waves. Wave size is
dependant on three factors: the strength of the wind; the length of time that the wind blows;
and the distance over, which the wind blows (the fetch).
The most common direction in which the waves move is determined by the prevailing winds
(i.e. the direction from which the winds blow most often). In the north-eastern portion of Lake
Ontario, the prevailing winds are from the south-west and less frequently from the east. This
area of Lake Ontario also has the greatest fetch. The fetch is known as the length of water
surface exposed to wind during wave generation. Because of this factor the shoreline at the
Scarborough Bluffs is exposed to the greatest wave action of the entire TRCA waterfront
leading to the creation of the cliffs. A wave will break when it reaches shallow water.
Therefore, the shoreline profiles have a great effect on the way the waves act in a certain area.
Wave hindcasting was used by Shoreplan to estimate the wave climate at an offshore location
where changes in water depths do not effect wave generation and propagation. The 1:100
year condition has a significant wave height of approximately 6.0 metres and a peak wave
period of 11 seconds. This wave will come from the east. The 1:100 year south-westerly
condition has a significant wave height of 4.5 metres with a peak wave period of 9 seconds.
Nearshore wave climates at the site were produced by transferring the 33 years of hourly
hindcast wave data from deep water in to the site using a numerical wave transformation
model. Wave transformation models are required to account for the effects the changing
bathymetry has on the waves as they propagate into the site. Nearshore wave height and wave
energy distributions along the Meadowcliffe Sector indicate that the magnitudes of the easterly
26
March 2010
and southerly peak wave heights are similar, however more than 70% of the nearshore wave
energy comes from the easterly direction.
Waves erode or wear away the base of the bluffs within the project area (e.g. Cudia Park and
Meadowcliffe Drive) and transport the eroded material westward along the coastline, a process
called littoral drift. Eventually, the material is deposited on the beach at Bluffers Park or is
moved offshore.
When cohesive shorelines recede due to wave-induced erosion, the vertical erosion noticeable
within the nearshore area is referred to as downcutting. Downcutting rates can be reasonably
estimated from surveyed profiles if a sufficient time exists between surveys. As part of the
Sylvan Avenue shoreline management plan Reinders et al (1994) estimated downcutting rates
for four profiles. Averaging their results they estimated that the current 2 metre contour would
be lowered by 0.9 metres in 40 years, 1.4 metres in 75 years, and 1.8 metres in 110 years.
Using profile data surveyed by TRCA in 2006, Shoreplan confirmed the rate of downcutting to
be consistent with Reinders et al (1994).
Water Quality
Water chemistry is a major environmental concern. Many parameters affect aquatic life, such
as fish and benthic invertebrates, in both the water column and sediment. Influences on lake
water quality include: inputs from water pollution control plants, backwash water from water
filtration plants, discharge from storm sewer outfalls, groundwater seepage, spills, erosion and
sedimentation, wet and dry atmospheric deposition, and urban run-off. The modification of
natural stream flows by dams and weirs can also affect water quality (TRCA, 2004).
The chemical characteristics of Lake Ontario have changed since the turn of the century.
These changes reflect the accelerated eutrophication taking place in the lake as a result of
urbanization. The following table contains the results from sampling events during the 1970’s.
The location of the sampling was approximately three kilometers to the east of Bluffer’s Park
Marina between Cathedral Park and Cudia Park within our study area limits.
Secchi disk readings offer a measurement of water clarity. According to the Provincial Water
Quality Guidelines (PWQOs), water should have a Secchi disk transparency of at least 1.2 m
(MOE, 1994). The information in Table 6 shows the transparency Secchi disk value ranged
between 1.33 m and 2.84 m. From this data it is safe to assume that this level of water clarity is
sufficient to support aquatic life.
Table 6. Historical Water Quality Measurements.
Nearshore
Secchi Disk Clarity (m)
Conductivity (umhos)
Total Phosphorus (mg/L)
Fecal Coliforms (#/100mL)
Offshore
Secchi Disk Clarity (m)
Conductivity (umhos)
Total Phosphorus (mg/L)
Fecal Coliforms (#/100mL)
1975 1976 1977 1978
1.77
331
0.05
4
1975
na
na
na
na
1.33
335
0.04
3
1976
2.44
331
0.03
2
1.44
328
0.05
7
1977
2.84
321
0.02
6
1.72
270
0.05
3
1978
2.53
278
0.03
4
Source: TRCA, 1979.
27
March 2010
The next measurement, conductivity is a measure of how well water can conduct an electrical
current. Conductivity increases with increasing amount and mobility of ions. Conductivity is an
indirect measure of the presence of dissolved solids such as chloride, nitrate, sulfate,
phosphate, sodium, magnesium, calcium, and iron, and can be used as an indicator of water
pollution. All results for conductivity are well within normal levels and should be of no concern
(Environment Canada, 2009).
Phosphorus is one of the key elements necessary for growth of plants and animals. Rainfall can
cause varying amounts of phosphates to wash from soils into nearby waterways. Phosphate
will stimulate the growth of plankton and aquatic plants which provide food for fish. Initially this
increased growth may cause an increase in the fish population and improve the overall water
quality (Environment Canada, 2009). However, if an excess of phosphate enters the waterway;
algae and aquatic plants will grow rapidly and use up large amounts of oxygen. This condition
is known as eutrophication. The rapid growth of aquatic vegetation can cause the death and
decay of vegetation and aquatic life because of the decrease in dissolved oxygen levels
(Environment Canada, 2009). According to the PWQOs to avoid nuisance concentration of
algae in lakes, average total phosphorus should not exceed 0.02 mg/L. The nearshore
measurements for total phosphorus are slightly above the PWQOs for nuisance algae
compared with the offshore measurements. This can be attributed to run-off from surrounding
residential lawns and is still therefore considered normal.
The presence of fecal coliform bacteria in aquatic environments could indicate that the water
has been contaminated with the fecal material of man or other animals. At the time this
occurred, the source water may have been contaminated by pathogens or disease producing
bacteria or viruses which can also exist in fecal material. Some waterborne pathogenic
diseases include typhoid fever, viral and bacterial gastroenteritis and hepatitis A. The presence
of fecal contamination is an indicator that a potential health risk exists for individuals exposed
to this water. Fecal coliform bacteria may occur in ambient water as a result of the overflow of
domestic sewage or nonpoint sources of human and animal waste (Environment Canada,
2009). According to PWQOs fecal coliform counts of fewer than 100 counts per 100 mL is
acceptable for recreation water use (MOE, 1994). As noted in the table above all of the
sampling stations are well below this guideline and are of no concern.
Soil / Fill Quality
The shorelands are composed of sand and silty sand. These sandy substrates derive from the
eroded material from the Scarborough Bluffs. Offshore bedrock occurs 12 to 19 m below lake
level, consisting of limestone formations of the Ordivician Period. There are no known soil
quality issues within this sector of the waterfront.
Sediment Quality (Contaminated Soils/Sediment/Seeps)
There are several factors that determine sediment contamination concentrations, these include;
proximity to urban and agricultural sources of contaminants, the characteristics of the water
body receiving the inputs, rates of shoreline erosion, binding mechanisms of sediment, the
amount of organic matter, and the percentage of fine sediment. Toxic substances within
sediments from industrial, municipal and non-point sources are a threat to the survival of
benthic organisms and other fauna that feed on them. Water quality can also be affected by
large amounts of contamination (CCME, 1999).
Historic sediment sample results for the regional study area exist for various offshore locations,
including south of Sylvan Avenue and south of the South Marine Drive revetment. Sediments
were tested for PCB/Organochlorine levels, general chemistry analysis (organic content,
28
March 2010
nutrients, and metals). Results of the laboratory analysis were compared against provincial
sediment quality guidelines. These guidelines provide reference points when evaluating
potential adverse biological effects on the aquatic community (CCME, 1999). The Provincial
Sediment Quality Guidelines were developed by the Ontario Ministry of the Environment to
assist with the protection of aquatic biological resources (MOE, 1993).
Table 7. Sediment Quality Results.
Sample
1990
Samples
1
2
3
4
1993
Samples
1
2
3
4
LEL
SEL
TOC
TP
TKN
Oil &
Grease
0.05
0.09
0.19
0.59
1250
555
290
250
70
50
110
300
104
119
420
164
0.16
0.19
0.13
1.1
1
10
590
710
270
380
600
2000
<50
<50
<50
140
550
4800
NA
NA
NA
NA
1500
As
Ni
Cd
Cr
Pb
Hg
Zn
LOI
1
0.8
1.6
1.6
NA
NA
NA
NA
0.2
0.4
<0.1
0.2
NA
NA
NA
NA
<1
<1
<1
12
<0.01
<0.01
<0.01
<0.01
13
15
18
33
2.8
0.5
0.9
1.4
<0.5
0.6
0.9
1.8
6
33
<5
<5
<5
19
16
75
<0.2
<0.2
<0.2
<0.2
0.6
10
10
9
<5
29
26
110
2.5
2.5
3
6
31
250
<0.1
<0.1
<0.1
<0.1
0.2
2
10
10
9
35
120
820
NA
NA
NA
NA
Source: TRCA, 1994.
Note: Unless otherwise noted, results are reported in milligrams per kilogram (ppm) except for loss on
ignition and total organic carbon which are expressed as a percentage, and cation exchange capacity
which is expressed in milli-equivalents per 100 grams (meq/100g).
Five (5) results exceeded the Lowest Effect Level (LEL), three (3) of which occurred in the
sediments from (1993), for chromium, nickel, and total organic carbon. Chromium and nickel
levels were not measured in 1990. Total phosphorus LEL was exceeded on two occasions;
station 1 in 1990, and at station 2 in 1993. Copper was detected at the LEL at station 4 (1993
sample).
No organochlorine compounds or PCB’s were detected in either the 1990 or 1993 sediment
samples. Four PAH compounds were detected in the 1993 samples, at levels at, or just above
detection limits. Fluoranthene was detected at stations 3 and 4 (1993); Pyrene and Chrysene
were detected at stations 1, 3, and 4; and Benzo(b)fluoranthene was detected at station 4
(1993) only. None of these detections exceeded the Lowest Effect Levels as designated by the
Ministry of the Environment (MOE).
Existing Transportation Routes
Major arterial roads that service the study area include Kingston Road, Eglinton Avenue East,
Brimley Road and Markham Road. The Canadian railway line is also located north of Kingston
Road, providing commuter service via GO Transit. There are public transit buses through the
communities along the Scarborough Bluffs (e.g. Bus 86 Scarborough) with various routes and
times (TTC, 2009).
Currently, there is no access road at the base of the Scarborough Bluffs in the project area;
however, there is a maintenance access road along the shoreline to the east of the project area
which is owned by TRCA. This service road is accessible via the Guild Inn and travels to the
west, ending at the terminus of Sylvan Park.
29
March 2010
Constructed Crossings
There are currently no constructed crossings within the study area.
3.2.2
Biological Environment
Wildlife Habitat
The project area provides limited habitat for mammal, bird and reptile species as the bluff face
is too steep. The open water zone may support migratory and resident waterbirds. Loons,
grebes, cormorants, geese, dabbling and diving ducks, gulls and terns use the open water
during migration. The open water habitat currently provides little forage such as fish, aquatic
invertebrates and zebra mussels for migrating and over wintering waterfowl and coastal birds
nesting outside of the project area.
Habitat Linkages or Corridors
The forested sections of the bluffs to the east and west of the project area provides corridors of
habitat which link to several nearby ravines, including Bellamy and Grey Abbey, as well as
linking smaller habitats with larger habitats such as East Point Park and the Highland Creek
valley. The Scarborough Bluffs corridor of habitat and resulting linkage of habitat allows
species such as coyote, red fox, and white-tailed deer to thrive on the waterfront (TRCA, 2004).
Significant Vegetation Communities
To the east of the study area the Bellamy Ravine shoreline sector has a bluff face that is
vegetated with a mixture of herbaceous plants, shrubs, and deciduous trees. The deep stream
gullies are vegetated with a mixture of birch, poplar, cherry, maple, oak, hawthorne and willow
while the steep cliffs remain bare. The forested bluff found east of Bellamy Ravine known as
Guild Woods supports a rare red ash and silver maple forest community.
Environmentally Sensitive / Significant Areas (Biological)
There are no designated biological Environmental Sensitive Areas located within the local study
area; however ESA#124 known as Guild Woods is located to the east of the Meadowcliffe
shoreline sector. This ESA is considered significant due to the presence of a red ash/silver
maple forest community which is relatively scarce on the Toronto waterfront. The ESA is
described as a flat tableland vegetated by mature forest cover comprised of white and red ash,
sugar maple, and American beech. The soils are are generally wet with pockets of eastern
hemlock, and white birch.
Fish Habitat
Historically, the open coast areas of the Scarborough waterfront supported breeding coldwater
fisheries which included lake trout, lake whitefish, round whitefish, and lake herring. The overwintering eggs and larvae of these coldwater species require cobble reefs, and rocky
shorelines that are kept clean of sediments by way of current and wave action (TRCA, 2006).
There are several limiting factors that affect fish production along Lake Ontario’s open coast
habitat. These include intense wave action, size of substrates, shoreline erosion, localized
water and sediment quality and water temperature fluctuations. Intense wave action during
storm events and high winds impedes the development of aquatic plant communities therefore
restricting feeding and cover areas for fish and other aquatic organisms (TRCA, 2004). As
stated in the previous section the sand and silt substrates that dominate the open coast
environment are unstable and subject to movement and transport along the waterfront due to
regular lake activities. This movement of fine sediment fills in interstitial spaces and restricts
spawning locations and oxygen availability to eggs that may have already been laid. Also the
30
March 2010
fine sediment offers very little cover and variability on the bottom providing little cover for fish.
The fish community of the eastern Toronto waterfront has been routinely monitored since 1989,
specifically Bellamy Ravine East Beach, Scarborough Shoreline Meadowcliffe, Bluffers Park
outer breakwall, and Bellamy Road. Results from seine and gill net locations from 1979 to 1986
are also available for areas such as Bluffers Park, Bellamy Ravine, and East Point waterfront
area. A species list of fish collected in these areas for all years sampled is reflected in the
following tables.
Based on their temperature requirements, fish species can be grouped into three broad fish
communities as follows: cold water, cool water and warm water. But it should be noted that
there is a certain amount of overlap among these broad community types. For example,
during the summer when waters are at their warmest in Ontario, it is not uncommon to find
some cold water species living in the same areas as cool water species, or cool water species
living in the same areas with warm water species (Eakins, 2007).
Table 8. Fish Species Collected on the Scarborough Shoreline.
Thermal Preference
Species List
Food Habits
Scientific Name
Cold
Piscivore
NonPiscivore
Warm
Cool


●

●
●
●

●
Alewife
Alosa
pseudoharengus
American Eel
Anguilla rostrata
Blacknose Dace
Rhinichthys obtusus


Bluntnose
minnow
Pimephales notatus
●




Bowfin
Amia calva
●


●
Brown bullhead
Ameirus nebulosus
●
Brown trout
Salmo trutta

●

●
Chinook salmon
Oncorhynchus
tshawytscha



●
●
Coho salmon
Oncorhynchus kisutch
●
●

Common carp
Cyprinus carpio
Luxilus cornutus
Emerald shiner
Notropis atherinoides
Fathead minnow
Pimephales promelas
Gizzard shad
Dorosoma
cepedianum

●










●
Common shiner


●
●
Lake chub
Couesius plumbeus




●
Lake trout
Salvelinus namaycush


●
●

Lake whitefish
Corregonus
clupeaformis


●

●
Logperch
Percina caprodes
●



●
Longnose dace
Rhinichthys catatactae

●


●
Longnose sucker
Catostomus
catostomus


●

●
Mottled sculpin
Cottus bairdi


●

●



●


●
●



●

●


●
●
●
●
31
March 2010
Thermal Preference
Species List
Food Habits
Scientific Name
Warm
Cool
Cold
Piscivore
NonPiscivore
Northern pike
Esox lucius

●

●

Pumpkinseed
Lepomis gibbosus
●



●
Rainbow smelt
Osmerus mordax


●

●
Rainbow trout
Oncorhynchus mykiss


●
●

Rock Bass
Ambloplites rupestris

●

●

Round whitefish
Prosopium
cylindraceum


●

●
Sand shiner
Notropis stramineus
●



●
Sea lamprey
Petromyzon marinus

●

●

Slimy sculpin
Cottus cognatus


●

●
Smallmouth Bass
Micropterus dolomieui
●


●

Spottail shiner
Notropis hudsonius

●


●
Tessellated darter
Etheostoma olmstedi

●


●
Threespine
stickleback
Gasterosteus
aculeatus

●


●
Trout-perch
Percopsis
omiscomaycus


●

●
Walleye
Sander vitreus

●

●

White bass
Morone chrysops
●


●

White perch
Morone Americana
●


●

White sucker
Catostomus
commersoni

●


●
Yellow perch
Perca flavescens

●

●

Source: TRCA, 2009 and Eakins, R. J. 2007. Ontario Freshwater Fishes Life History Database. Version 2.98. On-line
database. (www.fishdb.ca), accessed 9 September 2009.
Table 9. Additional Fish Species Collected on the Scarborough Shoreline
Preferred Habitat
Species List
Scientific Name
Alewife
Alosa pseudoharengus

●
American Eel
Anguilla rostrata



●
Blacknose Dace
Rhinichthys obtusus

●
Bluntnose minnow
Pimephales notatus

●

●
Bowfin
Amia calva


●
Brown bullhead
Ameirus nebulosus

●
Brown trout
Salmo trutta

●
●
Chinook salmon
Oncorhynchus tshawytscha
●

●
Coho salmon
Oncorhynchus kisutch
●
●
●
Common carp
Cyprinus carpio

●
Common shiner
Luxilus cornutus


●
Shoals
Exposed
Shores
Sheltered
Embayments
●
●
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March 2010
Preferred Habitat
Species List
Scientific Name
Emerald shiner
Notropis atherinoides

●
Fathead minnow
Pimephales promelas
Gizzard shad
Dorosoma cepedianum

●

●
Lake chub
Couesius plumbeus
●
●
Lake trout
Salvelinus namaycush
●
●

●
Lake whitefish
Corregonus clupeaformis
●
●

Logperch
Percina caprodes

●

Longnose dace
Rhinichthys catatactae
●

Longnose sucker
Catostomus catostomus

●
●

Mottled sculpin
Cottus bairdi

●
Northern pike
Esox lucius



●
Pumpkinseed
Lepomis gibbosus
Osmerus mordax

●
●
Rainbow smelt

●
Rainbow trout
Oncorhynchus mykiss
●
●
Rock Bass
Ambloplites rupestris
Round whitefish
Prosopium cylindraceum

●

●

●
Sand shiner
Notropis stramineus

●
●
Shoals
Exposed
Shores
Sheltered
Embayments

●
●



●
Sea lamprey
Petromyzon marinus
Slimy sculpin
Cottus cognatus

●
●
Smallmouth bass
Micropterus dolomieui
●
●

●
Spottail shiner
Notropis hudsonius

●
●
Tessellated darter
Etheostoma olmstedi

●
●
Threespine stickleback
Gasterosteus aculeatus

●
●
Trout-perch
Percopsis omiscomaycus

●
●
Walleye
Sander vitreus

●
●
White bass
Morone chrysops

●
●
White perch
Morone Americana


●
White sucker
Catostomus commersoni

●
Yellow perch
Perca flavescens


●
●
Source: TRCA 2009 and Eakins, R. J. 2007. Ontario Freshwater Fishes Life History Database. Version 2.98. On-line
database. (www.fishdb.ca), accessed 9 September 2009.
The fish community found at the site can be described as sparse but quite diverse. This can be
attributed to the relatively cold water and high wind and wave action found along the shores of
the Scarborough waterfront leading to a group a fish that is well adapted to these conditions.
Hypolimnetic upwellings are common throughout the area which results in cold water being
moved inshore by wind. These coldwater upwellings create intolerable conditions for most
warm water species. Therefore warm water species are typically found along the open coast of
the Scarborough waterfront during the summer months only.
Adversely, coldwater and game fish such as the salmonids are only found in the nearshore
areas of the shoreline during hypolimnetic upwelling events and are not considered permanent
33
March 2010
residents of the area (TRCA, 2006). These fish along with the other piscivores use this
nearshore area usually only during times of migration.
Using the fisheries data available for the Scarborough shoreline, each fish species preferred
habitat type, thermal and food guild is categorized in Table 7. The representation of the data in
this form can be used to classify the site as a cool to cold water fishery. Coolwater species
represent 52.5% of the total inventory. Cold water species represent 25% of the total inventory
and have highest percentage of piscivores at 12.5%. These findings are consistent with the
findings for the EA performed on the Guild Inn Sector of the Scarborough shoreline.
As stated above this section of shoreline is classified as a cool-cold water fishery but serves as
a migration corridor for other species during the summer months. There are several sheltered
embayments along this section of waterfront that provide significant warm water fish habitat
which include Bluffers Park and the mouth of Highland Creek. During periods of hot dry
weather with little to no wind or wave action, conditions in the nearshore areas of the project
site can be warm enough to support warm water fisheries allowing for migration between warm
water habitats. Therefore, this area of nearshore habitat acts as a corridor and is important to
allow for colonization and replenishment of fish communities in other isolated warm water
habitats.
Species of Concern
A local significance “L-Rank” has been created by TRCA and it is applied to species, or
communities to provide a measure of their biological significance, or abundance in a Greater
Toronto Regional context. Local ranks “L-Ranks” are assigned according to a variety of
biological criteria including provincial and national significance. L-Ranks represent a scale of
significance that ranges from L1 to L5. L1 or a low L-score represents a high significance, and
high L-score represents low significance. Also included is L+, which indicates a non-native
species or community which is not ranked in the range.
Typical L-Rank Description:
L1 Extremely significant in TRCA Region due to rarity, stringent habitat needs, and/or threat to
habitat
L2 Highly significant: occurs in high-quality natural areas and is probably declining in the
Toronto area, often already rare
L3 Locally significant: generally occurs in natural rather than cultural areas; may be vulnerable
to decline
L4 Generally secure; may be a conservation concern in a few specific situations
L5 Dependent on degraded, often urban habitats; not a conservation concern
L+ non-native species or community which generally requires management unless special
conservation concern exists
Some of the criteria used in this database include: local occurrence, population trend, habitat
dependence, area sensitivity, mobility restriction, and sensitivity to development. The following
table represents the “L” rating for species of concern for the Cudia Park/Bellamy Ravine section
of the Scarborough Shoreline. Several of the species in the table have an “L” rating of L2
indicating that this area contains species of concern and should be protected and maintained
in order to enhance diversity.
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March 2010
Table 10. Flora Species of Concern.
Scientific Name
Acer spicatum
Actaea pachypoda
Allium tricoccum
Anemone acutiloba
Asarum canadensis
Aster umbellatus
Betula allegheniensis
Carya cordiformis
Caulophyllum thalictroides
Corylus cornuta
Cornus rugosa
Desmodium glutinosum
Dryopteris marginalis
Elymus canadensis
Elymus hystrix
Helianthus decapetalus
Helianthus strumosus
Impatiens pallida
Juglans cinerea
Juncus torreyi
Polystichum aerostichoides
Quercus alba
Rosa blanda
Shepherdia Canadensis
Solidago arguta
Viburnum acerifolium
Flora Species of Concern
Cudia Park / Bellamy Ravine
Common Name
Level of Concern (L1-L4)
Mountain Maple
White Baneberry
Wild Leek
Sharplobed Liverleaf
Canadian Wild Ginger
Flat-topped White Aster
Yellow Birch
Bitternut hickory
Blue Cohosh
Beaked Hazel
Round-leaved dogwood
Pointed-leaved tick-trefoil
Marginal woodfern
Canada wild rye
Eastern bottlebrush grass
Thin-leaved sunflower
Paleleaf woodland sunflower
Pale touch-me-not
butternut
Torrey’s Rush
Christmas fern
White oak
Early wild rose
Ruset buffaloberry
Atlantic goldenrod
Mapleleaf viburnum
L4
L4
L3
L3
L4
L4
L3
L4
L2
L3
L3
L3
L4
L3
L4
L3
L4
L4
L3
L4
L3
L2
L4
L2
L4
L3
Source: TRCA, 2009.
The Monarch butterfly (Danaus plexippus) which inhabits the study area is designated as a
Species of Special Concern. The forest found at the Guild Inn to the east supports provincially
rare wood reedgrass (Cinna arundinacae).
Exotic/Alien and Invasive Species
An aquatic invader is a non-native species, whose introduction will likely cause (or has already
caused) damage to the host ecosystem, existing species therein, the economy or human wellbeing. Invasive species thrive in the absence of their native predators and have the potential to
drastically alter habitat, rendering it inhospitable for native species. Aquatic invasive species
(AIS) have already been responsible for significant devastation of some native fish species and
fisheries in Canada (DFO, 2009).
Within the aquatic community there are eight (8) alien fish species. Fish such as rainbow trout,
Chinook salmon, and brown trout have been introduced to improve recreational sport fishing
opportunities in Lake Ontario. Other species such as common carp and goldfish have also
been intentionally introduced, however are not considered a popular sport fish. White perch
are of concern as it can compete for habitat with walleye and potentially reduce its populations.
It also will interbreed with the native white bass (TRCA, 2004).
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March 2010
Another species of growing concern is the round goby. It has been captured in very low
numbers around the site in question however this fish is typically hard to capture with both the
electrofishing vessel and the seine net. Round Gobies have spread rapidly within the Great
Lakes since their discovery in 1990. They are very competitive and populate quite easily. In
addition to habitat domination, they will also eat the eggs and the young of indigenous fish. It
is presumed that they arrived via the ballast water of transoceanic vessels (DFO, 2009).
Terrestrial exotic species can cause problems similar to those threats within the aquatic
community. They also have the ability to out-compete native species and pose significant risk
for the continued existence of the species itself. Some of the exotic species include tree of
heaven, purple loosestrife, garlic mustard, and Norway maple. These species reproduce
prolifically and as mentioned above tend to out-compete many desirable plant species (GLIN,
2009).
Wildlife/Bird Migration Patterns
This area of shoreline along the Lake Ontario waterfront serves as a major migratory corridor
for wildlife and birds. This project site is located within an important migratory zone which
encompasses both the Atlantic and Mississippi flyways.
Songbirds rely on the vegetated slope of the Scarborough Bluffs when in need of rest, food, or
shelter from adverse weather conditions during migration. This habitat near the shoreline
serves as an important staging area for these birds when they are most vulnerable. The
following table represents a summary of the Toronto Ornithological Club database for bird
species observed between January 1, 1930 and August 18, 2002 at Bluffer’s Park, Cudia Park,
Sylvan Park, Guildwood Park, and Scarborough Bluffs.
Table 11. Bird Species Observed on the Scarborough Shoreline.
Common Name
Scientific Name
Red-throated loon
Gavial stellata
Common loon
Gavial immer
Pied-billed grebe
Podilymbus podiceps
Horned grebe
Podiceps auritus
Red-necked grebe
Podiceps grisegena
Double crested cormorant
Phalacrocorax auritus
Great blue heron
Ardea herodias
Green heron
Butorides virescens
Black-crowned night heron
Nycticorax nycticorax
Snowy egret
Egretta thula
Canada goose
Branta Canadensis
Trumpeter swan
Cygnus buccinator
Gadwall
Anas strepera
American black duck
Anas rubripes
Mallard
Anas platyrhynchos
Tufted duck
Aythya fuligula
Greater scaup
Aythya marila
King eider
Somatria spectabilis
White-winged scoter
Melanitta fusca
Long-tailed duck
Clangula hyemalis
36
March 2010
Common Name
Scientific Name
Bufflehead
Bucephala albeola
Common goldeneye
Bucephala clangula
Hooded merganser
Lophodytes cucullatus
Common merganser
Mergus merganser
Red-breasted merganser
Mergus serrator
Osprey
Pandion haliaetus
Northern harrier
Circus cyaneus
Sharp-shinned hawk
Accipiter striatus
Cooper’s hawk
Accipiter cooperii
Broad-winged hawk
Buteo platypterus
Red-tailed hawk
Buteo jamaicensis
American kestrel
Falco sparverius
Peregrine falcon
Falcoperegrinus
Killdeer
Charadrius vociferous
Spotted sandpiper
Actitis macularia
Ring-billed gull
Larus delawarensis
Herring gull
Larus argentatus
Iceland gull
Larus glaucoides
Kumlien’s gull
Larus glaucoides kumlieni
Glaucous gull
Larus hyperboreus
Great black-backed gull
Larus marinus
Caspian tern
Sterna caspia
Common tern
Sterna hirundo
Rock dove
Columbia livia
Black-billed cuckoo
Coccyzus erythropthalamus
Eastern screech owl
Otus asio
Chimney swift
Chaetura pelagica
Ruby-throated hummingbird
Archilochus colubris
Northern flicker
Colaptes auratus
Pileated woodpecker
Dryocopus pileatus
Hairy woodpecker
Picoides villosus
Yellow-bellied flycatcher
Empidonax flaviventris
Least flycatcher
Empidonax minimus
Eastern phoebe
Sayornis phoebe
Northern shrike
Lanius excubitor
Warbling vireo
Vireo gilvus
Blue jay
Cyanocitta cristata
American crow
Corvus brachyrhynchos
Black-capped chickadee
Parus atricapillus
Tree swallow
Tachycineta bicolor
Barn swallow
Hirundo rustica
Bank swallow
Riparia riparia
37
March 2010
Common Name
Scientific Name
Red-breasted nuthatch
Sitta Canadensis
Brown creeper
Certhia Americana
Carolina wren
Thyrothorus ludovicianus
Winter wren
Troglodytes troglodytes
Sedge wren
Cistothorus platensis
Marsh wren
Cistothorus palustris
Golden crowned kinglet
Regulus satrapa
Ruby-crowned kinglet
Regulus calendula
Blue-gray gnatcatcher
Polioptila caerulea
Swainson’s thrush
Cathrus ustulatus
Hermit thrush
Catharus guttatus
Wood thrush
Hylicichla mustelina
American robin
Turdus migratorius
Gray catbird
Dumetella carolinensis
Northern mockingbird
Mimus polyglottos
Brown thrasher
Toxostoma rufum
European starling
Sturnus vulgaris
American pipit
Anthus rubescens
Bohemian waxwing
Bombycilla garrulous
Orange-crowned warbler
Vermivora celata
Northern parula
Parula Americana
Yellow warbler
Dendroica petechia
Chestnut-sided warbler
Dendroica pensylvanica
Black-throated warbler
Dendroica caerulescens
Yellow-rumped warbler – Myrtle warbler
Dendroica coronata
Prairie warbler
Dendroica discolor
Palm warbler
Dendroica palmarum
Black and white warbler
Mniotilta varia
American redstart
Setophaga ruticilla
Ovenbird
Seirus aurocapillus
Mourning warbler
Oporornis Philadelphia
Wilson’s warbler
Wilsonia pusilla
Nashville warbler
Vermivora ruficapilla
Magnolia warbler
Dendroica magnolia
Pine warbler
Dendroica pinus
Bay-breasted warbler
Dendroica castanea
Blackburnian warbler
Dendroica fusca
Scarlet tanager
Piranga olivacea
Eastern towhee
Pipilo erythropthalamus
Fox sparrow
Passerella iliaca
Song sparrow
Melospiza melodia
White-throated sparrow
Zonotrichia albicollis
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March 2010
Common Name
Scientific Name
Dark-eyed junco
Junco hyemalis
Northern cardinal
Carinalis cardinalis
Rose-breasted grosbeak
Pheucticus ludovicianus
Indigo bunting
Passerine cuanea
Red-winged blackbird
Agelaius phoeniceus
Rusty blackbird
Eupahgus carolinus
Common grackle
Quiscalus quiscula
Orchard oriole
Icterus spurious
Baltimore oriole
Icterus galbula
American goldfinch
Carduelis tristis
Brown-headed cowbird
Molothrus ater
Source: Toronto Ornithological Club, 2002.
Wildlife Population
Reports conducted by TRCA (2000) indicate that this section of shoreline is very disturbed, with
significant fragmentation of natural areas. Overall, these areas attract a good assortment of
common garden and city birds, though sightings of unusual species have been observed.
Observed wildlife species within the immediate study area and adjacent woodlots are indicative
of well-established suburban residential areas usually associated with older more developed
areas.
Resident wildlife within the study area include Eastern red fox (Vulpes vulpes), eastern
cottontail (Sylvilagus floridanus), grey squirrel (Sciurus carolonensis), striped skunk (Mephitis
mephitis), raccoon (Procyon lotor), coyote (Cabis latran), little brown bat (Myotis lucifugus),
meadow vole (Microtus pennsylvanicus), white-footed mouse (Permyscus leucopus), muskrat
(Ondatra zibethicus), beaver (Castor canadensis), white-tailed deer (Odocoileus virginianus),
Eastern chipmunk (Tamais striatus), woodchuck (Marmota monax), and Virginia opossum
(Didelphis virginiana). The local wildlife populations are supported by the continuous corridor
of habitat provided by the Scarborough Bluffs (TRCA, 2004).
Wetlands
In 2008, TRCA constructed a wetland adjacent to the East Beach at Bluffers Park to capture
overland runoff and ground water seepage from the Scarborough Bluffs. The wetland project
included restoration of native wetland plant communities, creation of boardwalks, and
installation of post-and-rope fencing to direct public access through sensitive plant
communities. These works were completed as part of a recent initiative of the Mayor David
Miller to improve recreational beaches.
Microclimate
Meteorological conditions — wind, nearshore wave climate, regional climatic conditions, solar
heating, and thermal characteristics — have considerable influence on shoreline conditions
and aquatic habitats. Winds, in combination with over-water fetch lengths, determine wave
conditions across the Toronto waterfront. A high percentage of lake currents and most
nearshore waves are induced by wind conditions. Winds are responsible for the lake-wide
circulation patterns that create the west-to-east ambient currents throughout the Toronto
waterfront. Although prevailing winds are generally from the west, the much longer eastern
fetches produce far more wave energy coming from the east. In the eastern sector of the
39
March 2010
Toronto waterfront the predominant eastern wave energy is partially balanced by wave energy
from the southwest.
Daily and seasonal weather conditions, especially solar heating, play a critical role in the
ecology of Lake Ontario. The lake waters stratify according to temperature in the summer and
winter. The amount and intensity of solar heating defines the scope and extent of this thermal
stratification and the subsequent aquatic habitat conditions. Two additional temperatureinduced conditions that dramatically affect nearshore habitats are the formation of a thermal
bar and hypolimnetic upwellings.
Early in the spring the nearshore waters of the lake heat up and form a band of warm water that
is held in place by a thermal bar consisting of colder, denser off-shore water. The warmer
water builds in depth and concentrates warm water discharges from rivers, creeks and storm
drains within the nearshore area. This phenomenon typically lasts until mid June, and
surcharges the nearshore area with warm, nutrient-rich water. The early season influx of
nutrients has a profound effect on aquatic life by promoting primary production and
accelerating the establishment of warm, eutrophic conditions along the shoreline of the
oligotrophic Lake Ontario. The thermal bar dissipates into full stratification in the early summer
and under the appropriate wind conditions is vulnerable to hypolimnetic upwellings of deep
cold lake water.
Unique Habitats
As previously stated, the Scarborough Bluffs are utilized as songbird migratory corridor,
located within the migratory zone which encompasses both the Atlantic and Mississippi
flyways. In aquatic habitats, the combination of cold water and extensive wave action primarily
creates a coldwater fishery, however, sheltered embayments east of Bluffers Park and the
mouth of Highland Creek provide habitat for warm water species.
Areas of Natural Scientific Interest - Life Science (ANSI-LS)
The entire Scraborough Bluffs is considered an Area of Natural Scientific Interest for Life
Science (see Figure 7), as the bluffs possess the following notable life science features:
“The deep stream gullies are vegetated with a mixture of birch, popular,
cherry, ample, oak, hawthorne and willow while the steep cliffs are bare.
Some sections of the tableland rim contain maple-oak-ash. Numerous
metropolitan parks and residential development abut the cliff rim” (OMNR,
1984).
As the project area is along the shoreline of the Scarborough Bluffs, TRCA recognizes that the
life science features of the bluffs are significant. Any works conducted along this sector will be
conducted to minimize and mitigate potential negative impacts.
3.2.3
Cultural Environment
Traditional Land Uses
Archaeological evidence gathered in this area shows that the First Nations people established
settlements along the Scarborough Bluffs dating back 10,000 years, making this one of the
oldest inhabited sites in Toronto. Refer to Archaeological Resources, Built Heritage Resources
and Cultural Heritage Landscapes for more details.
Furthermore, Doris McCarthy, a renowned Canadian artist, bought her property at 1
Meadowcliffe Drive in 1939 and still resides on this property today. In 1986, Doris McCarthy
40
March 2010
was interested in conserving a portion of her property located on the bluffs and donated seven
(7) acres of her land to TRCA under the Erosion Control Agreement. In 1998, another portion of
her property was donated to the Ontario Heritage Trust, which is known as “Fool’s Paradise”
and is used for heritage and artistic activities. Fool’s Paradise is seen to have a rare
combination of natural, archaeological and cultural heritage.
Aboriginal Reserve or Community
There are no reserves or known communities within the study area.
Outstanding Native Land Claim
There are no known native land claims within the study area.
Riparian Uses
The study area is located within the “Cliffcrest” neighbourhood in the former City of
Scarborough. The property located within the study is mainly owned by private landowners,
more specifically there are 16 residential properties that back directly onto the bluffs. TRCA
owns some waterfront property towards the east end of the project area. The area below Cudia
Park is owned by TRCA and maintained by the City of Toronto. However, there will need to be
an agreement between the private landowners and TRCA prior to the commencement of the
shoreline remedial works.
Recreational or Tourist Use of Water Body and/or Adjacent Lands
The study area is located just east of Bluffers Park. This lakeside park features a double
launching ramp, visitors dockage, and yacht clubs. Part of the park provides secure berths for
over 500 boats operated by the Bluffers Park Boating Federation.
Recreational or Tourist Use of Existing Shoreline Access Locations
Bluffers Park has a day use park which includes a sandy beach, picnic areas, walks, lookouts,
and a restaurant.
As of the summer 2009, Bellamy Ravine has a formal gravel pedestrian pathway from the top of
Bellamy Ravine to the shoreline of Lake Ontario. Additionally there is a maintenance access
road located below Sylvan and South Marine Drives, located to the east of the project area,
which is accessed via the Guild Inn. This informal service road owned by TRCA provides
pedestrian access to the waterfront.
Aesthetic or Scenic Landscapes or Views
The Scarborough Bluffs stretch for about 14 km along the Lake Ontario shore, from the Eastern
Beaches of Toronto in the west and to West Hill in the east. The bluffs rise 65 m above the
water at their highest at Cliffside. The Scarborough Bluffs are considered a natural wonder that
was formed following the last ice age about twelve thousand years ago. The bluffs have been
formed primarily by erosion of the packed clay soil.
Archaeological Resources, Built Heritage Resources and Cultural Heritage Landscapes
The following information was provided by TRCA Archaeological Resources.
Palaeo-Indian Period - ca. 11,500 to 9,000 BP
Twelve thousand years ago as the glaciers retreated from southern Ontario, nomadic peoples
gradually moved into the areas recently vacated by the massive ice-sheets. As the glaciers
melted, much of the landscape of southern Ontario came to resemble spruce-tundra regions of
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the present day eastern sub-arctic. During this time period, the water levels and shorelines of
lakes Huron and Ontario fluctuated considerably due to large quantities of glacial meltwater.
Traditionally, archaeologists’ knowledge of the Palaeo-Indian occupations of southern Ontario
was limited primarily to sites associated with these glacial lake shorelines. However, recent
investigations of archaeological sites located in the vicinity of Toronto indicate that these
peoples also exploited interior locations away from glacial lake shorelines. It is thought that
these Palaeo-Indians lived in small family groups and hunted caribou and other fauna
associated with the cooler environment of that time. Archaeologists’ understanding and
reconstruction of this early period of Ontario’s past remains incomplete. Much of this
reconstruction is substantiated from a small number of sites, limited artifact collections, and
rare archaeological finds such as the discovery of arctic hare, fox, and possibly caribou bone
fragments at the Udora site (a Palaeo-Indian encampment) near the south shore of Lake
Simcoe.
At present, there is no evidence of Palaeo-Indian occupations along the shoreline of the project
area. This is likely due to the fact that water levels in Lake Ontario were slightly lower during
Palaeo-Indian times than they are now. Once the glacial meltwaters had drained out of the
Great Lakes, circa 11,400 years ago, Lake Ontario was approximately 80 metres below the
present water level. Evidence of Aboriginal occupations dating from that time until circa 4,000
years ago have likely been destroyed by rising waters or, much more recently, by the dredging
of the lake bottom by the ‘stone hookers’ in the mid-1800s. It is possible that many of these
early sites may be preserved underwater, and that these sites may be able to teach people of
the future about this era in Ontario’s history. Several Palaeo-Indian sites are known from areas
within the Humber River watershed suggesting that similar discoveries along the tablelands of
the Scarborough Bluffs may be discovered.
Archaic Period - ca. 9,000 to 3,000 BP
As the climate in southern Ontario warmed, the environments and fauna changed. As a result,
many new technologies and subsistence strategies were introduced and developed by the
Aboriginal peoples. Wood working implements such as groundstone axes, adzes and gouges
begin to appear, as do net-sinkers (for fishing), numerous types of spear points and items
made from Native copper, which was mined from the Lake Superior region. The presence of
Native copper on archaeological sites in southern Ontario and adjacent areas suggests that
Archaic groups were already involved in long range trade and interaction with one another.
The trade networks established at this time were to persist between Native groups until
European contact.
To harvest the new riches of the warming climate, Archaic bands of southern Ontario followed
an annual cycle which exploited seasonably available resources in differing geographic locales
within watersheds and along lakeshores. For example, from spring through fall, bands would
have joined together and inhabited sites in lakeshore environments where abundant foodstuffs
such as fish, waterfowl and wild rice enabled the establishment of larger multi-season
occupations. Due to the extreme difficulty of scaling the bluffs to reach the water’s edge and
the relatively low fisheries productivity associated with an exposed open coast environment, it
is unlikely that aboriginal communities would have used the Guildwood Parkway shoreline for
collecting aquatic foodstuffs and resources. As the seasons changed and aquatic resources
became scarce, these bands split into smaller groups and moved inland to exploit other
resources which were available during the fall and winter such as deer, rabbit, squirrel and bear
which thrived on the forested margins of these areas.
Very little is known about the specifics of life for the people of the Archaic period. This is due in
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part to the lack of detailed excavation of these sites, and part to the changes in water levels
discussed above. As well, archaeological sites representative of these early nomadic activities
are small and therefore often deemed insignificant. It is likely that many of these sites were
destroyed as development changed the face of the waterfront.
Initial Woodland Period - ca. 3,000 to 1,300 BP (AD 700)
Early in the Initial Woodland period (3,000 - 2,000 BP), band size and subsistence activities
were generally consistent with the groups of the preceding Archaic. Associated with the
earliest components of this cultural period is the introduction of clay pots. Ceramic vessels
provide a means for longer term storage of foodstuffs. With the ability to store foodstuffs
during times of plenty, the stress of harder times was greatly reduced as it would have been
possible to take advantage of the accumulated goods. Additionally, around 2,000 BP a
revolutionary new technology, the bow and arrow, was brought into southern Ontario and
radically changed the approach to hunting. These two technological innovations allowed for
major changes in subsistence-settlement patterns. As populations became larger, camps and
villages with more permanent structures were occupied longer and more consistently.
Generally, these larger sites are associated with the gathering of two or more band groups into
what are referred to as 'macrobands.' Often these larger groups would reside in favourable
locations to cooperatively take advantage of readily exploitable resources such as fish.
It was also during this period that more elaborate burial rituals such as cremation, burial mound
construction (as seen at the Serpent Mounds near Peterborough, Ontario, for example) and the
interment of numerous exotic grave goods with the deceased began to take place. In fact,
these goods, which include large caches of well-crafted lithic blades, sheets of mica, marine
shells, shark teeth, silver and copper beads, and artifacts such as platform smoking pipes and
decorative ear ornaments, all indicate that the Initial Woodland period was one of increased
trade and interaction between southern Ontario populations and groups from as far as the east
coast and the Ohio Valley.
Ontario Iroquoians (Late Woodland Period) - 1,300 to 450 BP (AD 700 to 1651)
Around AD 700 corn was introduced into southern Ontario from the south. With the
development of horticulture as the predominant subsistence base, the Late Woodland period
gave rise to a tremendous population increase and the establishment of permanent villages
(which were occupied from 5 to 30 years). These villages consisted of numerous cigar-shaped
structures, or "longhouses," made from wooden posts placed in the ground and tied together at
the top in an arch-like fashion. Although these windowless structures were only 6 metres (20
feet) wide (and the same in height), they extended anywhere from 9 to 45 metres (30 to 150
feet) in length providing shelter for up to 50 people. Quite often these villages, some of which
were 3 to 10 acres in size, were surrounded by multiple rows of palisades suggesting that
defence was a community concern during this period.
After centuries of small scale warfare and the gradual depletion of such resources as soil
nutrients and firewood, the Late Woodland groups that inhabited the Scarborough Area and
adjacent watersheds began moving their villages northward towards Georgian Bay. It was
these groups that eventually evolved into the Petun and Huron Nations witnessed and
recorded by the early French missionaries and explorers during the seventeenth century.
Ultimately, both of these groups were exterminated through contact with Europeans, the
spread of disease epidemics, and continued warfare with the Iroquois from New York State.
Contact Period - AD 1650 to 1800
During the late 1500s and early 1600s, European explorers sailed along the north shore of Lake
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Ontario and likely camped in the areas later to become Toronto and Eastern Scarborough.
They were not looking for a nice place to live, but were seeking a route that would take them to
the Orient. Etiénne Brûlé, sent to Pennsylvania by Samuel de Champlain in 1615, was likely
one of the first to see the stark and majestic Scarborough Bluffs.
For at least two centuries prior to British settlement, the Scarborough Bluffs and adjacent
tableland must have remained a harsh and unpopulated area. While the Maritimes and
Quebec were experiencing great changes brought by French and British exploration and
settlement, the Scarborough Bluffs likely saw humans only occasionally, either when Native
groups travelled through for food or trade, or when the occasional European fur trading or
exploring expeditions stopped to gaze at the spectacular view from the top of the bluffs. The
majestic cliffs would have dominated the landscape from the water. However, it was the forest
on top of the bluffs that would have made an outstanding place for humans to rest and gather
supplies but, at the time, was not a favoured location for year-round living due to the
inaccessibility to the shoreline and the lack of well defined surface water sources.
Following the dispersal of the Petun and Huron by the Iroquois in 1650, southern Ontario lay
vacant for fifteen years. Then, during the mid 1660s in an attempt to expand their fur hunting
grounds to the north, the Iroquois - or more specifically the Seneca - established a number of
villages along the north shore of Lake Ontario. These villages were large and at least two were
located in the Humber and Rouge River watersheds.
The early 1700s saw the arrival of the Mississauga from the north. Concentrated in what has is
now Etobicoke and Mississauga, these semi-nomadic Algonkian speakers most probably
gathered plant foods, hunted and fished in the watersheds to the west and along the lakeshore.
Following the American Revolution, displaced United Empire Loyalists sought land in Upper
Canada. The need for suitable land led to the Toronto Purchase in September of 1787,
encompassing an area from the mouth of Etobicoke Creek to Woodbine Avenue and almost as
far north as Newmarket. In 1805, this agreement was made official. By the mid 1790s, most of
the Mississauga groups had moved west to the Credit River and later to the Grand River, so
that only occasional hunting and trading parties were seen passing through the Toronto area.
Lands east of Woodbine Avenue were purchased as needed to connect Niagara with presentday Kingston. A road through Scarborough was built by settlers in 1801, which encouraged
further settlement in the area.
At present, TRCA database has record of registered archaeological sites (from the Ministry of
Culture) and indicates that there are four known sites within several kilometers of the study
area. One site is located near TRCA’s Guildwood shoreline project (Ministry Id# is AKGt-032).
This site is of an undetermined time period and cultural affinity. The three other sites include
the 'Midland' site (AkGt-007) a burial of undetermined age/culture, the 'McCowan' site (AkGt037) a multi-component (two or more occupations) probable campsite, and the 'Heinze' site
(AkGt-015) a campsite of undetermined age.
Historic Canals
There are no historic canals located within the project limits.
Federal Property
There is no federal property affected by or located within the project site.
Heritage River Systems
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There are no heritage river systems located within the project site.
3.2.4
Socioeconomic Environment
Surrounding Neighbourhood or Community
The neighbourhood surrounding the project area is characterized by low-density residential
properties. In the 1960’s, the city planners of Scarborough named the community Cliffcrest in
reference to the Scabrough Bluffs, which skirts the southern boundary of this neighbourhood.
A map illustrating the boundaries of the Cliffcrest community is shown in Figure 12.
Figure 12. Boundaries of Cliffcrest Community.
Source: City of Toronto, 2006.
The property located at 1 Meadowcliffe Drive is the home of Doris McCarthy, a renowned
Canadian artist. In 1986, Doris McCarthy was interested in conserving a portion of her property
located on the bluffs and donated seven (7) acres of her land to TRCA under the Erosion
Control Agreement. In 1998, Ms. McCarthy’s property along the crest of the slope, known as
“Fool’s Paradise” was donated to the Ontario Heritage Trust for heritage and artistic activities.
Fool’s Paradise is seen to have a rare combination of natural, archaeological and cultural
heritage.
The Cliffcrest community is located within Ward 36 of the City of Toronto. Cliffcrest is situated in
east Toronto. It is bounded to the west by Midland Avenue, Bellamy Road and Ravine to the
east, the Canadian National Railway (CNR) tracks to the north and Lake Ontario to the south.
The Cliffcrest community is home to approximately 14, 530 people and consists of about 5, 575
households. The community is composed of 17.4 % children (0 – 14), 12.9 % youth (15 – 24
yrs), 53.4 % working age individuals (25 – 64 yrs), and 16.4 % seniors (65 years or greater)
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(City of Toronto, 2001). The average household income is $72,521, below that of the larger
city, which averages $80,343 (City of Toronto, 2006).
Surrounding Land Uses or Growth Pressure
The study area is located within a well-established residential neighbourhood, and as such is
subject to limited growth pressure. Due to the age of the homes within the study area, there is
evidence of several properties undergoing major renovations; however presently there is no
new development.
Existing Infrastructure, Support Services, Facilities
There is no existing infrastructure within the limits of the proposed work, however, within the
study area there is typical residential infrastructure (e.g. electrical lines, storm and sanitary
sewers, watermains) as well as park-related infrastructure (e.g. asphalt pathways, parking lots,
and washrooms).
Pedestrian Traffic Routes
Bluffers Park, located to the west of the project area and Bellamy Ravine to the east provides
access to the waterfront for pedestrians. There is no waterfront beach or pedestrian access
along the shoreline south of Meadowcliffe Drive and Lakehill Crescent.
Property Values or Ownership
Within the study area there are twelve (12) properties along Meadowcliffe Drive and another
four (4) properties along Lakehill Crescent. The properties located within the study area
include private residential and a designated heritage site owned by Ontario Heritage Trust.
Due to the location of these properties and their view of Lake Ontario, these properties on
average have a market value estimated to be between $1.8 and $2 million.
Existing Tourism Operations
There are no known tourism operations within the project area. Bluffers Park to the west of the
local study area is a tourist area that offers a sandy beach, picnic areas, walks, lookouts, and a
marina. While the historic Guild Inn property to the east has unique formal gardens, art and
sculpture displays that attracts visitors and is a popular wedding photography site. Plans are
underway to introduce a restaurant, hotel and conference centre.
Property/Farm Accessibility
Currently Cliffcrest community memebers have restricted access to the project area from the
top of the bluffs due to the height and angle of the bluff face. However, as previously noted,
several Meadowcliffe and Lakehill property owners have riparian rights to the shoreline, as such
an agreement must be in place with these property owners prior to any commencement of
shoreline works.
3.2.5
Engineering/Technical
Rate of Erosion in Ecosystem
In 2006, Terraprobe carried out detailed site investigations and slope stability assessments for
the bluff fronting Meadowcliffe Drive. Terraprobe noted that the average bluff slope inclination
was about 1.2 h: 1.0 v (horizontal: vertical). The typical bluff height was reported as 57 metres.
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The upper portion of the slope was characterized as predominantly bare with inclinations
varying from 1 h: 1 v to 1.4 h: 1.0 v. Using aerial photographs Terraprobe estimated the
average annual recession rate at the toe of the bluff from 1980 to 2005 to vary from 1.1 to 1.3 m
per year. Terraprobe identified that a stable bluff profile can be achieved if the toe of the bluff is
stabilized. An average value of 1.2 metres per year was adopted for this study.
Sediment Deposition Zones in Ecosystem
The net littoral drift direction at this site is from east to west. Approximately 25,000 m3 /y of
sediment that is supplied through shoreline erosion along the Scarborough Bluffs (R.C. Harris
filtration plant to East Point), 20,000 m3 of which originates from the Meadowcliffe Drive sector.
A study conducted by Baird (1994) concluded that Bluffers Park could be considered to be a
complete littoral barrier. It was found that approximately 20 to 25% of the incoming supply
would bypass the eastern-most headland, but would likely either be deposited in the entrance
channel or deflected offshore at the western end of the park.
Flood Risk in Ecosystem
Varying water levels along the shoreline play a factor in localized flooding in low-lying areas.
Water levels are known to change on a daily, seasonal, and annual basis. Waterfront projects
are managed and designed in response to these known changes.
Slope Stability
As previously noted, Terraprobe (2006) estimated the average annual recession rate at the toe
of the bluff from 1980 to 2005 to vary from 1.1 to 1.3 m year. An average value of 1.2 m per
year was adopted for this study. Average bluff slope inclination was about 1.2:1.0
(horizontal:vertical). Once the toe is stabilized the lower section of the bluff will obtain a stable
slope of 2.5: 1.0 (h: v) and the upper 30 metres will obtain a stable slope of 1.5: 1 (h: v).
Using stable slope calculations from earlier work Terraprobe determined a long-term stable
slope crest (LTSSC) position based on the 2005 position of the toe. Terraprobe also
recommended that any toe protection works be situated 30 m lakeward of the existing toe of
the bluff. That 30 metre buffer provides a suitable measure of safety for construction activity
along the toe and allows room for the bluff to self-stabilize without talus spilling over the access
road or protection structure. Positioning the landward edge of the shoreline protection
structure 30 metres offshore of the current shoreline will also affect the predicted LTSSC.
Existing Structures
The tableland at Meadowcliffe Drive and Lakehill Crescent is privately owned with 16 residential
properties backing onto the bluffs. In all it is estimated that 12 properties are affected by
erosion and bluff instability. Terraprobe (2006) estimated that the LTSSC is predicted to be
projected inland by about 48 m on average from the 2005 slope crest assuming that wave
erosion at the slope toe had been mitigated. Terraprobe’s final report, concluded that at least 5
houses are between 0 and 10 m from the LTSSC and that several others are within 25 m of this
projected slope crest. A heritage property and municipal roadway are also within the area of
identified risk. Based on the significant recession of the slope toe and respective recession of
the LTSSC, Terraprobe strongly recommended that shoreline works be implemented.
Hazardous Lands / Hazardous Sites
Hazard lands within the Regional Study Area include all nearshore waterfront lands which are
susceptible to flooding or which have unstable slopes or soils. TRCA administers Ontario
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Regulation 166/06: Development, Interference with Wetlands and Alteration to Shorelines and
Watercourses. Through this regulation TRCA has the ability to prohibit, regulate or require
permission for development where the control of erosion may be affected. TRCA has
delineated a Regulation Limit which identifies TRCA’s area of interest based on hazards
associated with the Lake Ontario shoreline including the 100 year flood level and predicted
LTSSC of the bluffs. All residential properties located along the shoreline within the study area
are within this Regulation Limit.
4.0
DESCRIPTION OF PRELIMINARY ALERNATIVE CONCEPTS
Eight (8) variations of four (4) preliminary concepts were developed to address the erosion
problem at Meadowcliffe Drive. The variations included protecting either the entire study area
or only the portion in front of Meadowcliffe Drive as well as using either land access or marine
construction techniques. Each of these preliminary designs represents all reasonable and
feasible alternative solutions to the problem, including a “Do-Nothing” alternative. These
alternative options are outlined in Section 4.1 through Section 4.7.
4.1
Preliminary Alternative Concepts
4.1.1
“Do-Nothing” Alternative
The “Do-Nothing” option is a mandatory alternative that must be considered in the Class EA
process, as it helps to justify the need to undertake a remedial flood or erosion control project.
Should the “Do-Nothing” option or other Conservation Authority programs such as land
acquisition be deemed to be a more acceptable solution, then there is no further consideration
for remedial action and the Class EA process terminates.
Under the “Do-Nothing” alternative erosion will continue along the shoreline east of the beach
retained by the Bluffers Park headland. As the shoreline erodes the beach will continue to
“grow” in an eastward direction gradually increasing the length of shoreline protected by the
beach. The shoreline that is far enough away to not be influenced by the beach will continue to
recede at approximately the long-term average annual recession rate. Terraprobe (2006)
determined that the average annual recession rate in front of Meadowcliffe Drive is 1.2 metres
per year. The recession rate will decrease moving westward until the point where the Bluffers
Park East Beach provides full protection against wave induced bluff erosion. Figure 13 shows
the estimated position of the bluff toe and top of slope in 100 years, based on an average
annual recession rate of 1.2 metres per year away from the influence of the beach. The
planning horizon for the “Do-Nothing” scenario is 100 years.
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Figure 13. The "Do - Nothing" alternative depicts the potential position of the bluff toe and crest
predicted in 100 years. Source: Shoreplan Engineering Limited, 2007.
The cost of the “Do-Nothing” option was determined by reviewing the estimated 2009 market
value of the affected properties and the potential cost of relocation or decommissioning
affected infrastructure (e.g., gas lines, electrical, water and sewer connections). These cost
estimates include a 15% contingency allowance, but are still only concept level cost estimates.
Based on these assumptions this alternative is valued at $27.6 million.
4.1.2
Preliminary Concept 1a – Headland Beach, Meadowcliffe Drive only
This preliminary concept consists of a cobble beach held in place by a series of shore parallel
headlands and protects only the bluff fronting Meadowcliffe Drive. For this concept an access
road is first constructed parallel to the shore, approximately 30 metres offshore of the existing
toe of the bluff. Headlands in the order of 80 to 100 m long are then constructed in front of the
access road. The spacing between the headlands can be varied but is in the order of 100 to
150 m. The headlands are connected to the shore via access roads and are protected with
large armour stones. The toe of the stones is excavated into the lakebed to allow for the future
downcutting of the cohesive profile. The area between the headlands will consist of rubble
material covered with a layer of beach cobbles. The beach cobbles will be dynamically stable,
meaning that the profile shape will adjust to different wave conditions and water levels. A
conceptual drawing of this preliminary concept is presented in Figure 14.
The LTSSC is based on a 30 metre lakeward translation of the LTSSC determined from 2005
existing conditions by Terraprobe. The line was moved lakeward to account for the effect of
constructing the shoreline protection 30 metres offshore of the toe of the bluff. It can be seen
that the projected LTSSC with shoreline protection indicates that the two easternmost dwellings
on Meadowcliffe Drive (#2 and #10) will be threatened by erosion within the 100-year planning
horizon. That threat can be eliminated through the use of a buttress.
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Figure 14. Preliminary Concept 1a - Headland Beach. Meadowcliffe Drive only. Source: Shoreplan
Engineering Limited, 2007.
Construction costs for Preliminary Concept 1a were estimated using unit prices from recently
tendered projects and may be considered to represent conditions in 2007. These cost
4.1.3
Preliminary Concept 1b – Headland Beach, bluff protection over full project site
Preliminary Concept 1b is the same as Preliminary Concept 1a except that Concept 1b protects
the bluff over the full project site. A conceptual drawing is presented in Figure 15. The
position of the LTSSC illustrated in the concept plan was determined by translating the LTSSC
lakeward to account for proposed position of the protection structures, 30 m from the existing
shoreline.
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Figure 15. Preliminary Concept 1b - Headland Beach, bluff protection over full project site. Source:
Shoreplan Engineering Limited, 2007.
Construction costs for Preliminary Concept 1b were estimated using unit prices from recently
4.1.4
Preliminary Concept 2a – Groyne/headland beach, Meadowcliffe Drive only
This preliminary concept also uses a headland retained beach but the headlands are
constructed from groynes rather than the shore parallel structures used in concepts 1a and 1b.
The groynes are higher in elevation than the offshore headlands and do not allow the beach
material to move behind the heads of the groynes. This will allow finer beach gravel (20 mm
diameter) to be used. Preliminary Concept 2a would only protect the area in front of
Meadowcliffe Drive, stopping at the western most groyne (see Figure 16). The LTSSC
accounts for proposed position of the protection structures, 30 m from the existing shoreline.
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Figure 16. Preliminary Concept 2a & 2b – Groyne/headland beach. Source: Shoreplan Engineering Limited,
2007.
Construction costs for Preliminary Concept 2a were estimated using unit prices from recently
4.1.5
Preliminary Concept 2b – Groyne/headland beach, bluff protection over full
project site
The shoreline geometry makes the use of goyne headland across the entire project site
impractical. As such, Preliminary Concept 2b uses a boulder berm to protect the shore from
the end of Concept 2a groynes to the Bluffers Park beach (see Figure 16). Shoreline
protection in Concept 2a in Figure 16 stops at the western-most groyne. The position of the
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LTSSC reflects the proposed position of the protection structures in relation to the existing
shoreline.
4.1.6
Preliminary Concept 3 – Breakwater (marine construction) + cobble beach (land
construction)
This preliminary concept is similar to Concept 1 in that it uses shore parallel headlands to retain
a cobble beach, but these headlands are not connected to the shore. This concept was
developed to consider a protection system that could be constructed in part using marine
access rather than land access. The access road and cobble beach would still be constructed
from land but the headlands would be constructed using marine equipment. All material used
in the construction of the headlands would be supplied by barge which would significantly
reduce construction traffic to and from the immediate site, although the barges would likely be
loaded at Bluffer’s Park. This option would therefore not reduce construction traffic in the
general neighbourhood. The position of the LTSSC shown in Figure 17 takes into account that
the protection structures are located 30 m offshore.
Figure 17. Preliminary Concept 3 - Breakwater (marine construction) + cobble beach (land
construction). Source: Shoreplan Engineering Limited, 2007.
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Construction costs for Preliminary Concept 3 were estimated using unit prices from recently
4.1.7
Preliminary Concept 4a – Headland/groyne (marine construction)
Preliminary Concept 4a consists of constructing a long groyne intended to retain a sand beach.
The groyne would be built using marine supply and construction. The length of the groyne
would be similar to the length of the Bluffer’s Park headland, measured in an offshore direction.
The size of the beach retained by the groyne would be similar to the existing beach retained by
Bluffer’s Park and the beach would be allowed to fill in naturally from the existing littoral drift.
The position of the LTSSC was determined by translating the LTSSC lakeward to account for
the 30 m offshore position of the proposed protection.
Construction costs for preliminary concept 4a were estimated using unit prices from recently
4.1.8
Preliminary Concept 4b - Headland/groyne (marine construction) + rubble access road
(narrow)
Preliminary Concept 4b is the same as 4a except that a groyne plus a narrow access road
would be built. Constructing a narrow access road from rubble would stabilize the bluff until
the beach filled in, but it would require land access and therefore some construction traffic.
There would, however, be significantly less construction traffic than associated with concepts 1
and 2.
4.1.9
Preliminary Concept 4c - Headland/groyne (marine construction) + sand beach
(dredged)
Preliminary Concept 4c is the same as 4a and 4b except that for concept 4c the beach would
be pre-filled using dredged material. Pre-filling the beach would minimize impacts associated
with interrupting the littoral drift but the costs would be significant. Preliminary Concepts 4a, b
and c are shown in Figure 18.
Construction costs for Preliminary Concept 4c were estimated using unit prices from recently
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Figure 18. Preliminary Concept 4a, 4b + 4c – Headland/groyne (marine construction) + additional
protection. Source: Shoreplan Engineering Limited, 2007.
5.0
EVALUATION OF PRELIMINARY ALTERNATIVE CONCEPTS
The baseline information was used to evaluate the alternative design concepts giving specific
consideration to the positive and negative impacts on the existing physical, biological,
socioeconomic, and cultural environments, as well as technical and engineering concerns. The
results of the evaluation are outlined under the respective evaluation criteria categories below.
5.1
Evaluation Criteria
To ensure that the proposed solution best meets the project objectives, Shoreplan Engineering
Limited, the public and agencies had several discussions to determine the most essential
evaluation criteria in relation to the physical, biological, cultural, social, economic, and
technical engineering elements. Each of the eight (8) preliminary concepts were evaluated with
the criteria outlined in Section 5.1.1 to 5.1.4 and is summarized in Table 12.
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5.1.1
Physical Criteria
To achieve the project objective of preserving or enhancing the ecological conditions of the
shoreline, the following five physical evaluation criteria were considered as part of the
evaluation of the alternatives:
•
•
•
•
•
5.1.2
Consideration of sediment supply and movement
Design structures to withstand coastal processes
Preserve a unique landform, a section of the Scarborough Bluffs
Prevent or minimize negative updrift and downdrift impacts
Prevent or minimize negative water quality impacts
Biological Criteria
To achieve the project objective of preserving or enhancing the biological conditions of the
shoreline and slope, the following four biological evaluation criteria were considered as part of
the evaluation of the alternatives:
•
•
•
•
5.1.3
Ensure no net loss of aquatic habitat
Preserve habitat linkages and corridors
Preserve unique aquatic and terrestrial habitats
Prevent or minimize negative impacts to existing vegetation
Cultural and Socioeconomic Criteria
As part of TRCA’s overall commitment to make the waterfront a place that achieves a wide
range of objectives including waterfront access, and improvement of waterfront aesthetics, the
evaluation of alternatives also considered the ability to satisfy the following objectives:
•
•
•
•
•
•
•
•
5.1.4
Provide waterfront access to improve recreational use of shoreline
Improve waterfront aesthetics
Ensure compatibility with government initiatives
Determine capital and maintenance costs
Prevent or minimize negative impacts to historical and cultural features or resources
Prevent or minimize negative impact to the adjacent shoreline
Ensure public safety
Improve scenic views and vistas
Technical and Engineering Criteria
To achieve the project objective of creating a safe shoreline that supports the marine functions
of Lake Ontario, the following six technical considerations were considered as part of the
evaluation alternatives:
•
•
•
Mitigate the instability and erosion of a section of the Scarborough Bluffs
Ensure no negative impacts to existing structures or infrastructure
Eliminate risk to life and property
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•
•
Diverse shoreline treatments
Construction of the shoreline protection (Scheduling)
The advantages and disadvantages of each of the preliminary concepts have been considered
against the evaluation criteria developed by agencies, public and Shoreplan Engineering Ltd.
The results of this evaluation are summarized in Table 12.
Table 12. Results of Evaluation Preliminary Concepts
EVALUATION
Alternative Advantage Disadvantage
CRITERIA
PHYSICAL
Sediment supply
and movement
Do Nothing
Concept 1a
●
●
Concept 1b
●
Concept 2a
●
Concept 2b
●
Concept 3
●
Concept 4a
●
Concept 4b
●
Concept 4c
●
Coastal processes
and updrift/
downdrift impacts
Do Nothing
Concept 1a
Concept 1b
Concept 2a
Concept 2b
Concept 3
Concept 4a
Concept 4b
Concept 4c
Unique landform
●
●
●
●
●
●
●
●
●
Designed to withstand coastal processes
●
●
●
●
Concept 3
Concept 4b
Protecting an area of shoreline not required
Protects the shoreline
●
Concept 2b
Concept 4a
Risk to Scarborough Bluffs
●
Concept 1b
Concept 2a
No impacts, as current conditions will be
maintained
No significant impact as the current
condition to sediment supply is insignificant
Potential impact to beaches to the west due
to disruption of sediment movement
westward
No significant impact as the current
condition to sediment supply is insignificant
westward
westward
westward
westward
westward
Shoreline continues to be at risk, as bluffs
cannot withstand wave action
Do Nothing
Concept 1a
Effect on Environment
●
●
57
March 2010
Concept 4c
●
Do Nothing
●
No change
●
No significant impacts to ANSI-ES and ESA
#123
Disrupts ANSI-ES and ESA #123
BIOLOGICAL
Unique
aquatic/terrestrial
habitats
Concept 1a
Concept 1b
Concept 2a
●
●
Concept 2b
●
●
●
●
●
Concept 3
Concept 4a
Concept 4b
Concept 4c
No significant impacts to ANSI-ES and ESA
#123
CULTURAL AND SOCIOECONOMIC
Waterfront access,
aesthics, views and
vistas
Do Nothing
Concept 1a
Concept 1b
Concept 2a
Concept 2b
●
Increase access and potential improvement
●
●
●
●
Concept 3
●
●
●
Concept 4a
Concept 4b
Concept 4c
Government
Initiatives –
Strategies to
improve the
waterfront
Concept 1b
Concept 2a
Concept 2b
●
Potential improvement
●
●
●
No improvement
No improvement
●
Continual costs to relocate residents and
infrastructure
Economical
●
Cost prohibitive
●
Concept 1b
Economical
●
Cost prohibitive
Concept 4c
●
●
●
●
●
Do Nothing
●
Risk to public
Concept 2b
Concept 3
Concept 4a
Concept 4b
Public Safety
No improvement
●
Do Nothing
Concept 2a
No change
Concept 4b
Concept 1a
Minimal access and improvement
Concept 4a
Capital and
maintenance costs
●
●
●
●
Concept 3
Concept 4c
●
Do Nothing
Concept 1a
No access
Concept 1a
Concept 1b
Concept 2a
Cost prohibitive
Cost prohibitive
Cost prohibitive
Cost prohibitive
Minimal risk to public
●
●
●
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March 2010
Concept 2b
●
Concept 3
●
Concept 4a
●
Concept 4b
Concept 4c
●
●
Risk to public as the shoreline is in close
proximity to eroding bluff
TECHNICAL
Erosion and Slope
Stability
Do Nothing
Concept 1a
●
●
Concept 1b
Concept 2a
●
●
Concept 2b
●
Concept 3
●
Concept 4a
Concept 4b
Concept 4c
Existing structures
and infrastructure
●
●
Do Nothing
Concept 1a
Concept 1b
Concept 2a
Concept 2b
Concept 3
Concept 4a
Concept 4b
Concept 4c
Loss of life and
property
●
●
●
●
●
●
●
●
●
●
Do Nothing
●
Concept 1a
Concept 1b
Concept 2a
Concept 2b
Concept 3
Concept 4a
Concept 4b
Will not preserve the bluffs
Will stabilize and protect properties at risk
minimal erosion to the bluffs
Protects properties not at risk but will
stabilize and minimize erosion to the bluffs
Risk to five (5) residential dwellings and
associated infrastructure
Potential to eliminate risk to dwellings and
infrastructure
infrastructure
infrastructure
infrastructure
infrastructure
infrastructure
infrastructure
infrastructure
Risk to severely reduce size of properties as
LTSCC recedes
Potential to reposition LTSSC to reduce loss
of property
of property
of property
of property
of property
of property
of property
●
●
●
●
●
●
●
Source: TRCA, 2009.
59
March 2010
5.2
Public Evaluation of Preliminary Alternatives Concepts
CLC meeting #2 was held on February 7, 2007 at 1 Eastville Avenue, and was attended by
several staff from TRCA, staff from Shoreplan Engineering Ltd., Councillor Brian Ashton, several
local property owners, representatives for Lorenzo Berardinetti, M.P.P., a representative from
the Ontario Heritage Trust, and a City of Toronto staff member. Shoreplan Engineering Ltd.
(Shoreplan) presented nine alternative design concepts, and provided rough cost estimates for
each of the proposed options. A comment form was distributed to the CLC Committee to
provide feedback on each of the options presented, to select the preferred design concept,
and to assess the importance of the evaluation criteria for each of the concepts presented.
It was communicated to the CLC members that the rating of the criteria would have an impact
on the overall evaluation of the preferred option. Further it was explained that the rating of
each individual criterion may not be held on par, based on project specific constraints as
identified on a project by project basis. The evaluation is based on the screening criteria
mandated in the Class EA document (Conservation Ontario, 2002).
In order to assess the relative importance of the evaluation criteria, CLC members were asked
to rank each criterion on a scale of 1 to 5, 5 being the most important, 1 being the least
important, NC being “no comment”. The results of the rankings from the five (5) returned
comment sheets are documented in Table 13 and illustrated in Figure 19. Criteria listed as
“other” were specific recommendations by CLC members.
Table 13. Rankings of Proposed Evaluation Criteria.
Biological
Aquatic Habitat
Habitat Linkages or Corridor
Terrestrial Habitat
Vegetation
Cultural and Socioeconomic
Access to Water
Appearance
Compatibility with Government Policies
Costs (Capital)
Costs (Maintenance)
Historical and Cultural Features or
Resources
Impact on Adjacent Shoreline
Public Safety
Support of Park Uses
Views and Vista
Physical
Littoral Drift (Sediment Supply and
Movement)
Other Coastal Processes (Wave Activity)
Unique Landforms (e.g. Dunes)
Updrift/Downdrift Impacts
Water Quality and Circulation
Technical and Engineering
Diversity of Shoreline Treatments
Erosion Mitigation
Existing Structures or Infrastructure
Risk to Life and Property
Scheduling (Phasing)
5
1
4
3
3
4
1
3
1
2
2
1
1
1
1
1
3
1
4
2
1
3
2
1
2
1
2
1
NC
1
2
1
3
1
1
1
4
1
2
4
2
1
2
2
3
3
1
3
3
1
1
3
1
1
2
2
1
1
Total
4
4
4
4
Total
4
4
4
4
4
Weight
3.5
4.0
3.3
3.8
Weight
3.0
3.5
4.0
4.8
4.0
4
4
4
4
4
Total
3.8
4.0
4.5
4.0
4.0
Weight
4
4
4
4
4
Total
4
4
4
4
4
4.3
4.3
3.5
3.8
4.3
Weight
4.3
4.8
4.5
5.0
4.3
Median
3.65
Median
4.0
Median
4.3
Median
4.5
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March 2010
Other
Add bluff stabilization methods
Pedestrian linkage (trails)
Source: TRCA, 2009.
Total
1
1
1
1
Weight
4.0
4.0
Median
4.0
Results of Proposed Evaluation Criteria
Median Values (out of a
maximum of 5)
5
Biological
4
Cultural / Socioeconomic
3
Physical
2
Technical / Engineering
1
Other
0
Evaluation Criteria Categories
Figure 19. Results of the Evaluation Criteria by category as ranked by CLC members,
expressed as median values. Source: TRCA, 2009.
As illustrated in Table 13 and Figure 19 the technical and engineering (e.g. erosion mitigation,
risk to life and property) and physical (e.g. coastal processes, unique landforms, water quality)
criteria were considered to be of greatest importance by the CLC members.
Furthermore, the results of the returned ranking forms also indicated that the preferred design
concept selected by the CLC members was the Headland Beach Concept (1a), which provides
protection to Meadowcliffe Drive only. TRCA received several of the following comments on
the forms:
•
•
•
•
Headland Beach – Meadowcliffe Drive (Concept 2a) is the only concept considered to
be the most practical in terms of cost, property protection, and beach access for the
public.
Headland Beach – full site (Concept 1b) is effective but costly. The member has
reservations about implementing shoreline protection for the entire project limits since
the majority of the erosion is concentrated at the Meadowcliffe Drive shoreline.
Groyne Retained Sand Beach – Pre-fill Beach (Concept 4c) is too expensive.
The shoreline from Bluffers Park to Port Union should be connected in order to facilitate
pedestrian recreational use and future TRCA shoreline protection construction or
maintenance.
The documentation of this CLC meeting is contained in Appendix C.
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March 2010
5.3
Agency Evaluation of Preliminary Alternative Concepts
Once the CLC’s evaluation of each approach was reviewed and discussed, TRCA completed a
further examination of each of the preliminary concepts. This included an extensive
examination of the types and extents of impacts, both positive and negative, that each
alternative method would have, including but not limited to:
•
•
•
•
5.3.1
The significance of the expected environmental effects
The degree of the effectiveness of the method
The extent of the technical feasibility
The magnitude of costs
The “Do-Nothing” Alternative
The environmental effects of a “Do-Nothing” approach relates to the potential long-term affects
of shoreline erosion on the terrestrial and cultural environment. These predicted problems are
largely associated with the ongoing loss of shoreline. Under the “Do-Nothing” alternative
erosion will continue along the shoreline east of the beach retained by the Bluffers Park
headland.
If left unprotected the crest of the bluffs is anticipated to recede by approximately 48 m within
the next 100 years. This loss of land would place approximately twelve (12) residential
dwellings in immediate risk and would affect several other properties by severely reducing the
amount of overall property. A heritage property, municipal roadway and supporting stormwater
drainage system would also be affected by the predicted rate of erosion.
Although the “Do-Nothing” alternative would not require any financing up front, ongoing costs
would be required to relocate servicing, and replace municipal infrastructure. Additional costs
would be required to relocate or replace the affected residences. Therefore this alternative is
not considered technically feasible due to the risk to public infrastructure and property.
5.3.2
Preliminary Concept 1a – Headland Beach, Meadowcliffe Drive only
This preliminary concept consists of a cobble beach held in place by a series of shore parallel
headlands and protects only the bluff fronting Meadowcliffe Drive. This design would not
impact or interrupt the existing littoral drift. The sediment budget data showed that, on
average, less than 5,000 cubic metres per year of sediment is currently transported to the site.
The sediment transport pathways analysis showed that the existing wave climate is capable of
transporting the full sediment supply past the site in water depths of approximately 2.5 metres
below datum, and deeper which corresponds to the deepest toe depth of the headlands.
Regional impacts of each proposed alternative, including this concept, relates to the
elimination of sources of sediment transport material due to shoreline protection. The shoreline
protection works will reduce the amount of sediment transported by littoral drift from the
Meadowcliffe Drive area. This will significantly reduce the amount of sediment being supplied
to the fillet beach at Bluffer’s Park. However, as sand is bypassing the easternmost headland
at Bluffer’s Park, but not the entire park itself, reducing the sediment supply will not have a
62
March 2010
significant impact. Since Bluffer’s Park is considered to be a complete littoral barrier downdrift
affects will not be noticed.
From a recreational standpoint this is a good concept as the shore protection and associated
maintenance road would provide public shoreline access for passive waterfront recreation.
Furthermore, with the shoreline protection in place, southwest waves would transport sediment
onto the shoreline east of Bluffer’s Park. Ultimately, this process would cause the beach to
expand during low water level conditions.
This solution is particularly desirable with consideration of the financial costs, as the design is
the most economical to implement. Moreover, this alternative is the most technically feasible
with the least impacts to the natural, cultural and socioeconomic environments.
5.3.3
Preliminary Concept 1b – Headland Beach, bluff protection over full project site
This preliminary alternative is similar to Concept 1a, however this design will be constructed
along the full project site. As the Meadowcliffe Drive area is the only area of shoreline with
active erosion caused by wave action at the toe of the bluff, additional protection to the area of
shoreline fronted by beach is not considered warranted. The protection of the additional area
to the west of Meadowcliffe Drive unnecessarily increasing the amount of lakefilling required,
consequently increasing the loss of aquatic habitat. Moreover, this area is designated a life
science ANSI and ESA which would be negatively altered following protection. Therefore, this
alternative is not considered a viable option due to the significant negative impacts on the
environment.
5.3.4
Preliminary Concept 2a – Groyne/headland beach, Meadowcliffe Drive only
This preliminary concept also uses a headland retained cobble beach but the headlands are
constructed from groynes rather than the shore parallel structures used in concepts 1a and 1b.
The groynes are higher in elevation than the offshore headlands and do not allow the beach
cobbles to move behind the heads of the groynes. The groynes will allow finer beach fill to be
used although it would still be stone material. The higher elevation and proposed material of
the shoreline protection will have a considerable impact to the aesthetics of the shoreline.
5.3.5 Preliminary Concept 2b – Groyne/headland beach, bluff protection over full project site
This preliminary alternative is similar to Concept 2a, except the headland retained cobble
beach would be constructed along the full study area. As previously noted with option 1b, the
benefit of lakefilling the area adjacent to Cudia Park is not considered to outweigh the negative
impacts and costs associated with the increased shoreline protection.
5.3.6
Preliminary Concept 3 – Breakwater (marine construction) and cobble beach (land
construction)
This preliminary concept is similar to Concept 1 in that it uses shore parallel headlands to retain
a cobble beach, but these headlands are not connected to the shore. This concept was
developed to consider a protection system that could be constructed using marine and land
access. The access road and cobble beach would still be constructed from land but the
headlands would be constructed using marine equipment. All material used in the construction
of the headlands would be supplied by barge which would significantly reduce construction
63
March 2010
traffic to and from the immediate site, although the barges would likely be loaded at Bluffer’s
Park. This option would therefore not reduce construction traffic in the general neighbourhood.
Additionally it should be noted that marine construction options significantly increases the cost
of construction.
From a recreational standpoint, the proposed offshore breakwater would be considered a
negative impact as it is anticipated marine construction would disrupt boaters launching from
or based at Bluffer’s Park. Furthermore, the community members would not be content with the
considerable alteration to the natural aesthetics of the shoreline.
The excessive cost of construction and the negative impacts perceived by constructing
offshore breakwaters causes this alternative to be eliminated as a viable solution.
5.3.7
Preliminary Concept 4a – Headland/groyne (marine construction)
The advantage of 4a is that it reduces the amount of materials required for construction and
reduces the impacts associated with construction traffic. However, these advantages are
outweighed by the impact of marine construction on recreational boating (see Section 5.3.6).
Moreover this concept requires more time than the other options to effectively stabilize the
eroding slope as the creation of the beach is dependant on the sediment supply that can be
generated from the existing littoral drift. As discussed in Section 5.3.2, there is a low sediment
supply along the Meadowcliffe shore sector. As such it would take many years for the beach to
develop. Development of the beach is critical to influencing the stabilization of the adjacent
bluff. Consequently, this option is not viable as there would be additional loss of property and
potential risk to residential dwellings along the crest of the bluff during the period in which the
beach is forming.
5.3.8
Preliminary Concept 4b - Headland/groyne (marine construction) and rubble access
road (narrow)
Preliminary Concept 4b is the same as 4a with the exception that a groyne plus a narrow
access road would be built. Constructing a narrow access road from rubble would stabilize the
bluff until the beach forms, but it would require land access and therefore some construction
traffic. There would, however, be significantly less construction traffic than associated with
concepts 1 and 2 as the amount of material required for construction is reduced.
The construction of an access road would stabilize the shoreline and prevent the erosion to the
slope and similar to concept 4a, the beach will be naturally filled by the existing littoral drift.
However, the narrow access road and naturally filled beach would not be accessible to the
community due to the associated safety risk with bluff instability and potential for landslides.
With consideration for the rationale identified in Section 5.3.6 in addition to the limited
community accessibility to the shoreline this alternative has been eliminated as a viable option.
5.3.9
Preliminary Concept 4c - Headland/groyne (marine construction) and sand beach
(dredged)
This alternative is similar to Concept 4a and 4b, however the beach would be pre-filled using
dredged sand material. Pre-filling the beach would minimize any impacts associated with the
64
March 2010
littoral drift. Furthermore, from a recreational standpoint the creation of a sand beach would be
considered highly attractive and valuable to the community. While this concept would increase
the recreational use and aesthetics of the shoreline, the costs are almost three times higher
than all other options. Based on cost this option has been eliminated.
6.0
PREFERRED ALTERNATIVE
The results of the evaluation of alternatives led to the preliminary identification of Concept 1a
(headland beach protecting Meadowcliffe Drive only) as the Preferred Alternative. Selection of
this option as the Preferred Alternative was based primarily on the following reasons:
•
Provides an attractive, diverse habitat
•
Consistent with proven shoreline protection utilized along this section of waterfront
•
Aesthetically pleasing and resembles shoreline to the east of Bellamy Ravine
•
Potential to improve terrestrial and fish habitat
•
Most cost efficient of all options
•
Protects toe of bluffs currently impacted by wave erosion
Based on the position of the LTSSC with the implementation of Concept 1a it was determined
that refinement of the alternative was required and is described in Section 6.1.
6.1
Refinement of the Preferred Alternative
As previously noted, the shoreline protection proposed as part of the Preferred Alternative will
stop the toe erosion at the base of the bluffs, however the position of the LTSSC will continue
to recede and may eventually threaten human life and property at the eastern portion of this
shoreline sector at risk (see Figure 20). As the objective of the project, is to protect human life
and property from the hazards of erosion and slope instability, a buttress at the base of the
bluffs at the east end of the shoreline sector has been proposed as part of the remedial works
to ensure long-term protection of the affected properties. The proposed buttress would be
constructed using earth, rock or rubble fill from the toe of slope to elevation 84 m, with an
inclination of 2.5:1 (H:V). The buttress would have a horizontal bench with a width of 25 m and
extend 40 m southward from the existing slope toe.
65
March 2010
Figure 20. LTSSC position in relation to properties 1, 2 and 10 Meadowcliffe Drive.
Source: Terraprobe, 2009.
In accordance with the Class EA planning and design process, once the Preferred Alternative
method is selected it is to be subjected to a more detailed study of the net impacts likely to be
associated with its implementation, known as a detailed environmental analysis. A further
determination can then be made regarding how the potential net negative impacts can be best
dealt with at the detailed design level.
6.2
Description of the Preferred Alternative
The Preferred Alternative is based on Preliminary Concept 1a, the headland beach protecting
Meadowcliffe Drive only. Appendix B shows a plan and typical sections for the preferred
alternative. It consists of a cobble beach retained by 4 headlands. The end headlands will be
constructed like “L” groynes, with armour stone along the outside of the headlands. The
western-most headland has a small spur on its west side to help retain any sand transported
alongshore from the Bluffer’s Park beach. The two central headlands will constructed from
shore but only the shore-parallel component of those headlands will be armoured. The
temporary access roads out to the headlands will eventually be covered with beach cobbles.
Construction will start with a 10 metre wide access road located approximately 30 metres
offshore of the existing bluff. The offshore side of the headlands will be located near the 72.0
metre contour line. The toe will be excavated into the lakebed to allow for the future
downcutting of the cohesive profile. The two central headlands will be approximately 60
metres long at the crest and the spacing between the headlands will be in the order of 100 to
150 metres. Beach cobble sizes will be determined during detailed design. The beach cobbles
will be dynamically stable, meaning that the profile shape will adjust to different wave
66
March 2010
conditions and water levels but overall will be stable. The underlying rubble material will not be
exposed during these normal profile adjustments.
Following construction of the shoreline protection TRCA will monitor recession of the slope on
an annual basis to determine the need for further works which may include a buttress as
conceptually illustrated in Figure 20.
Once the preferred concept was chosen the Class EA process continued to the Detailed
Environment Analysis stage, described further in Section 7.0 of this report.
7.0
ENVIRONMENTAL SCREENING OF PREFERRED ALTERNATIVE
7.1
Detailed Environmental Analysis of the Preferred Alternative
To complete the detailed environmental analysis of the preferred alternative, the information
collected for the baseline inventory is examined in greater detail to confirm potential impacts,
refine methods of mitigation, and identify any unforeseen impacts. The evaluation of impacts
includes both temporary impacts during construction of the undertaking, and permanent
impacts due to operation and maintenance of the undertaking after construction. Table 14
screens the potential negative and positive effects of the proposed undertaking on the
environment during construction and maintenance phases. It includes the consideration of the
magnitude, geographic extent, duration, frequency, permanence or reversibility and ecological
context of the effects, as well as proposed mitigation measures and any residual effects.
Environmental components that have been identified as potentially having an effect on the
environment, both positive and negative, are discussed herein. Those components determined
to be not applicable (n/a) as identified in Table 14, have been omitted from further discussion.
67
March 2010
Rating of Potential Effects
-L NIL +L +M +H NA
Physical
●
Comments
Monitoring program in place to maintain integrity of headlands and dynamic beaches.

●

●
Construction will not occur within ANSI – ES area.

●

●

●

●

●
Construction will not occur within the ESA areas.

Mitigative measures will be taken to minimize impacts of equipment use during construction and operation.
●

 Construction will not impact outfall located within the Bellamy Ravine.
Mitigative measures will be taken to minimize impacts of equipment use during construction and operation.
●
●
 Design considers effect of extreme lake levels, storm influences, and wave conditions.
 Design considers low lake levels.
●

●
All construction to be carried out at the toe of the bluff.
●
●

●
No significant impacts are expected.

●
Minor local impacts are expected with wave sheltering and reflections.
●

Mitigative measures will be in place during construction to protect water quality.
●
Only clean aggregates and/or rubble will be used in construction.
●

●

●
●
 See Unique Landforms.
●
Biological
Proposed remedial work will improve terrestrial habitat currently threatened by erosion.
●


Project will result in an improvement to habitat linkages and corridors.
●
●
●
Proposed remedial work will help with the re-establishment vegetation on the bluff face.

Construction will not occur within an ESA.

Project will improve nearshore habitat conditions for local fishery. DFO will approve compensation plan prior to construction.
●
●
●

●
●
No species of concern located within the project area.


Restoration plan will inclue native vegetation wherever feasible.
In the long-term, wildlife habitat will improve as vegetation growth increases on the bluff face.
-L
NIL
●
Rating of Potential Effects
+L +M +H NA
●

No significant impacts are expected.

Comments
Cultural
●

●

●

●

●

●

●
●
●

Temporary disruption only.

Access to shoreline improved in the long-term.

Bluffs will lose their “majestic” cliff-like look.

Project restricted to the base of the bluffs.
●
●

●
●

Socioeconomic
●

●


Temporary disruption only.
Protects existing infrastructure and services.
●


●
Shoreline protection and access road will provide pedestrian access along the shoreline.
●
Protection work will reduce or eliminate further loss of property and protect property values along Meadowcliffe Drive.
●

●
●

●
●

Proposed works will stop erosion at the toe of the Bluffs.

Overall effect on the existing beach will not be noticeable.
●


Bluffs will erode to a stable angle of repose thus increasing slope stability.
●
●

Provides protection for existing structures in the long-term.
 Slope instability will be reduced.
●

and rating them as relatively high (H), medium (M), low (L) or not applicable (NA). From Conservation Ontario, Class Environmental Assessment for Remedial
●
7.1.1
Physical Environment
Unique Landforms
The Scarborough Bluffs are the most significant unique landform within the study area. The
bluffs have been eroding at an average rate of 0.45 metres per year since the 1900s. It is
speculated that this erosion has been accelerated by the historic removal of aggregate
materials such as gravels, cobbles and boulders which were once found in abundance on the
shoreline and nearshore waters.
The project will result in the preservation and enhancement of gravel, cobble and sand
beaches which mimics the natural protection once afforded to the Scarborough Bluffs. The
proposed shoreline design will protect the toe of the bluffs, allowing the over-steepened slopes
to establish a more natural angle and increase the growth of vegetation in this section of the
bluffs. As the bluffs will be protected as a result of the preferred alternative, no significant
impacts are expected on the unique landforms within the study area.
Area of Natural and Scientific Interest – Earth Science (ANSI-ES)
The preferred alternative will only be protecting below Meadowcliffe Drive, as such there is no
remedial work proposed for the ANSI -ES identified at Cudia Park. Therefore no significant
impacts are expected.
Environmentally Sensitive / Significant Areas (Physical)
The preferred alternative will be shoreline protection along the entire base of the Meadowcliffe
Drive, plus bank stabilization along the most eastern portion, below 1, 2 and 10 Meadowcliffe
Drive; as such the Sequence of the Scarborough Bluffs (ESA #123) is only included in the
project area that will undergo bank stabilization. TRCA recognizes that the bluffs within the
study area are significant and any works conducted along this sector will be conducted to
minimize and mitigate potential negative impacts.
Air Quality
The trucks required to bring aggregate and fill material for the construction of the remedial
works can increase dust in and around the project site. In order to minimize the amount of
dust generated by construction, mud build up on the roads surrounding the site will be
removed by street sweepers when required and trucks transporting earth fill to the site will be
covered with a tarpaulin. Dust polymers approved by the Ministry of the Environment will be
applied along TRCA service access road to minimize the disturbance of dust.
Efforts will be taken to transport construction materials to the site and stockpile them to avoid
having to use the access roads during dry summer months when dust problems are
exacerbated. Furthermore, truck drivers will also be reminded by the on-site construction
supervisor of the City of Toronto’s anti-idling bylaw. By taking these precautionary measures
the effect of the project on local air quality will be limited and temporary, therefore causing no
significant residual impacts.
Agricultural Tile or Surface Drains
The preferred alternative will not have any impact on the outfall located within the Bellamy
Ravine which is located just east of the project area.
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Noise Levels and Vibrations
The construction of the shoreline protection will require heavy machinery and the import of
aggregate and fill material. Earth movers and trucks in particular will cause a temporary
increase in noise and vibration.
During the construction of the shoreline protection of the Meadowcliffe Drive sector there is
anticipated to be minimal noise and vibration. As enforced on all TRCA project sites, all
construction trucks will meet manufacturer sound attenuation specifications; and the project
site will be in compliance with time prohibitions for delivery of materials and operation of
construction equipment per the Toronto Municipal Code, Chapter 591. Furthermore, other
applicable noise protocols will be enforced to diminish the potential for noise from construction
activity.
In regards to the potential vibration from the construction activity, TRCA contacted an
engineering firm, Terraprobe Limited with professional experience to comment about the
effects of vibration on the bluffs (refer to Appendix D to view a copy of the letter). Terraprobe
stated that the vibration from the construction would not have any significant adverse impacts
on the stability of the Scarborough Bluffs. At any time during construction if there is any
question of the stability of the bluffs due to the vibration of construction activity TRCA will
respect the need for an engineering firm to complete vibration monitoring.
Furthermore, to limit the effect of noise and vibrations caused by truck and equipment
operation, construction will occur Monday to Friday during regular working hours, from 7:30
am to 4:30 pm, to avoid disturbing the area residents during their leisure time. The effect of
construction equipment and trucks on noise and vibration will be minimized and temporary in
duration; therefore no significant residual impacts are expected.
Water Flow Regime
The construction of the shoreline protection works will not alter the water levels in Lake Ontario.
Existing Surface Drainage / Groundwater Seepage / Groundwater Recharge and Discharge
Zones
The construction of the Preferred Alternative will not alter the existing surface drainage from the
tablelands along Meadowcliffe Drive.
Groundwater seepage along the Meadowcliffe Sector was documented to be along the upper
bluff face from the top of the slope crest to approximately 15 m below the crest. As the
shoreline protection works will be at the base of the sector it will not impact or change the
groundwater seepage zones. However, as the preferred alternative of the shoreline protection
incorporates bank stabilization work below 1, 2 and 10 Meadowcliffe Drive there will be a
drainage system implemented in this area of the Meadowcliffe Sector to minimize any impacts
to the groundwater seepage zones.
Littoral Drift
The potential effects of the undertaking on littoral drift can be described in terms of local and
regional impacts. Local impacts are those caused by the proposed structures interference with
littoral transport. Regional impacts are generally associated with the loss of littoral transport by
eliminating or reducing a historic source of material or permanently trapping littoral material.
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The proposed erosion control works will not impact or interrupt the existing littoral drift. The
sediment budget data showed that, on average, less than 5,000 cubic metres per year of
sediment is currently transported to the site. The sediment transport pathways analysis
showed that the existing wave climate is capable of transporting the full sediment supply past
the site in water depths of approximately 2.5 metres below datum, and deeper which
corresponds to the deepest toe depth of the headlands.
Regional impacts of the proposed undertaking relate to the elimination of sources of sediment
transport material due to shoreline protection. The shoreline protection and slope stabilization
works will reduce the amount of sediment transported by littoral drift from the Meadowcliffe
Drive area. This will significantly reduce the amount of sediment being supplied to the fillet
beach at Bluffer’s Park. However, as sand is bypassing the easternmost headland at Bluffer’s
Park, but not the entire park itself, reducing the sediment supply will not have a significant
impact. Since Bluffer’s Park is considered to be a complete littoral barrier downdrift affects will
not be noticed.
Minor adjustment is anticipated to the plan shape of the fillet beach once the western-most
headland is constructed.
Wave Climate – Other Coastal Processes
The proposed design was developed to mimic natural coastal processes at the site. The
beaches have been designed to be dynamic in nature, meaning that under varying wave and
water level conditions, the beaches will vary in width, length above water and in profile.
The size and placement of the armourstone was calculated with consideration for the existing
wave climate including wave height, wave spectra, wave refraction, duration of exposure, water
depth, water fluctuation, and downcutting of the foreshore. The shoreline design will withstand
or self-adjust to wave conditions; therefore no significant residual effects are anticipated.
Water Quality
During construction there is potential for increased turbidity of the nearshore waters adjacent to
the project site. Sediments may be carried into the lake indirectly via surface runoff or directly
through the deposit of sediment laden materials during the lakefill process. To ensure that
turbidity is not affected by soils used during the lakefilling process, unconfined materials will be
used only when a protective rubble core isolates the fill area from the open lake. The potential
effect of lakefilling operations on water clarity will be further mitigated by ensuring that TRCA
lakefilling activities are undertaken in accordance with its Erosion and Sediment Control
Guidelines for Construction (TRCA, 1994), and in compliance with TRCA’s Lakefill Quality
Control Program (LQCP).
The LQCP is designed to protect water quality from the potential use of unsuitable soil or fill
materials during lakefilling operations. No significant residual impacts are anticipated as the
above described measures will eliminate the risk of introducing contaminants and mitigate the
potential affects of construction on the turbidity of nearshore waters.
The erosion control works will eliminate erosion of the bluffs caused by wave action. As a
result there will be a reduction of sediment entering the lake which will have a positive affect on
water quality.
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Soil/Fill Quality
Activities associated with the construction of the project are not expected to have any impact
on soils or sediment quality. No existing contamination has been identified on-site. Only soils
approved under TRCA’s LQCP will be imported to the site to maintain the quality of the local
soils. Due to these practices, no significant impacts are expected.
Existing Transportation Routes
The potential affect of the project on existing transportation routes as it relates to the proposed
construction access route is addressed in Section 9.0.
7.1.2
Biological Environment
Wildlife Habitat
Construction activities are expected to temporarily displace wildlife during site preparation and
shoreline protection. Activities are expected to temporarily displace resident wildlife only. All
work will be scheduled to avoid critical habitat, therefore no residual impacts are anticipated.
Overall, the wildlife habitat will improve as a result of the habitat compensation measures.
Habitat Linkages or Corridors
The steep slopes of the Scarborough Bluffs are largely untouched by the adjacent residential
communities creating a continuous habitat linkage across the north shore of Lake Ontario from
Highland Creek to the central waterfront. The proposed works will only encroach on the most
eastern portion of the bluffs along the Meadowcliffe Sector and will provide wildlife with
improved access to the lake. Therefore the project will result in an improvement to habitat
linkages and corridors.
Significant Vegetation and Communities
The proposed shoreline and slope stabilization of the Meadowcliffe Sector will allow vegetation
to re-establish. All disturbed areas will be restored. Overall, the wildlife habitat in project area
will be improved.
Environmentally Significant Areas – Biological
TRCA recognizes that natural habitat areas within the study area are significant and any works
conducted along this sector will be conducted to minimize and mitigate potential negative
impacts. The Preferred Alternative will be shoreline protection along the entire base of the
Meadowcliffe Drive, plus bank stabilization along the most eastern portion, below 1, 2 and 10
Meadowcliffe Drive; as such ESA #123 will not be impacted.
Fish Habitat
During lakefilling operations fish will be temporarily displaced from the shoreline to avoid noise
or localized turbidity. To mitigate the alteration, disruption or destruction of fish habitat
resulting from the release of sediments or contaminated lakefill into Lake Ontario, TRCA will
rely on employing best environmental management practices (BEMPs) during construction.
These practices are outlined in TRCA’s Erosion and Sediment Control Guidelines for
Construction and LQCP.
The lakefilling associated with the shoreline protection will likely result in the harmful alteration,
disruption or destruction of fish habitat (HADD). To ensure adequate compensation for this
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HADD, TRCA will work with Fisheries and Oceans Canada (DFO) to develop a fish habitat
compensation plan which will include:
•
•
•
Creation of cobble/gravel beaches
Creation of offshore reefs and shoals
Wetland creation at an off-site location along the waterfront
A fish habitat compensation plan will be developed using the Habitat Alteration Assessment
Tool and will require the review and approval of Fisheries and Oceans Canada. The aquatic
enhancements planned for the project will contribute to increased aquatic habitat productivity
to ensure that the project has no significant residual impacts on fish or fish habitat.
Species of Concern
TRCA recognizes the presence of provincially and regionally uncommon plant species within
the Cudia Park/Bellamy Ravine section of the Scarborough Shoreline. The shoreline protection
and bank stabilization works will be limited to the base and most eastern portion of the
Meadowcliffe Sector Bluffs. There are no L1 or L2 species located within the project area,
therefore no significant impacts are expected to any species of concern.
Exotic/Alien and Invasive Species
Only native species, indigenous to the north shore of Lake Ontario will be used during
implementation of the project. As the project will not introduce or encourage exotic or invasive
plant species no significant residual impacts are expected.
Wildlife/Bird Migration Patterns
Construction activities are expected to temporarily displace wildlife during site preparation and
shoreline protection. Activities are expected to temporarily displace resident wildlife only. No
residual impacts are anticipated. In the long-term, the wildlife habitat will improve as vegetation
growth increases on the bluff face.
Wildlife Population
The project will not have any negative effects on wildlife population within the project area.
Microclimate
The proposed works will not have an effect on the microclimate.
Areas of Natural Scientific Interest - Life Science (ANSI-LS)
The Preferred Alternative will only be protecting below Meadowcliffe Drive, as such there is no
remedial work proposed for the ANSI -LS identified at Cudia Park. Therefore no significant
impacts are expected.
7.1.3
Cultural Environment
Traditional Land Uses
The proposed work will not have any effect on traditional land uses.
Riparian Uses
The proposed work will require acquisition of riparian rights along Meadowcliffe Drive to ensure
that the remedial works are constructed and maintained on public land. The affected riparian
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area is located outside of the area currently accessible to the private landowners; as such the
Preferred Alternative will not have any negative impact on riparian uses.
Recreational or Tourist Use of Water Body and/or Adjacent Lands
The project will not have an effect on Bluffer’s Park which is located west of the project area.
Recreational or Tourist Use of Existing Shoreline Access Locations
TRCA is aware that many members of the communities along the Scarborough Bluffs utilize the
network of shoreline service roads to gain access to the shoreline. However, as the primary
purpose of these service roads is to provide TRCA with vehicle and equipment access to the
shoreline, TRCA must restrict public access during periods of active operation in order to
ensure public safety. While service roads are not intended as a formal pedestrian trail, TRCA
understands the importance of maintaining this informal public use. As such TRCA is
committed to allowing the public access to affected sections of the service road for recreational
purposes on public holidays, weekday evenings (between 5:00 pm and 7:30 am) and
weekends (from 4:30 pm no Friday to 7:30 am on Monday). TRCA will also endeavour to
minimize disruption to public use of the service road during warm weather months from April to
October. Moreover, TRCA will commit to provide the public with formal notification of
construction or maintenance activities to improve communication with the community.
Aesthetic or Scenic Landscapes or Views
The implementation of the shoreline protection works will, in the long run, affect the shape and
look of the Scarborough Bluffs along the Meadowcliffe Drive Sector. The Scarborough Bluffs
will lose their “majestic” cliff-like look.
Archeological Resources, Built Heritage Resources and Cultural Heritage Landscapes
Since the project is restricted to the bluffs at the base of Meadowcliffe Drive there are no
archeological sites within the project area.
7.1.4
Socioeconomic Environment
Surrounding Neighbourhood or Community
The surrounding neighbourhood or land uses will not be affected by the proposed works.
Surrounding Land Uses or Growth Pressure
The surrounding land uses or growth pressure will not be affected by the proposed works.
Existing Infrastructure, Support Services, Facilities
The proposed works will reduce the current rate of erosion that is occurring in this area and will
aid in the protection of the homes located on Meadowcliffe Drive. All construction will occur at
the toe of the bluffs and therefore there are no anticipated impacts to any structures on the
tableland as a result.
Pedestrian Traffic Routes
Presently, the Meadowcliffe Sector is not accessible for pedestrian or vehicle traffic. The
access road to be constructed and maintained as part of the proposed shoreline protection will
in future however, provide pedestrian shoreline access. Section 9.0 provides further
description of potential impacts and benefits related to the project as it relates to construction
access.
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Property Values or Ownership
The proposed undertaking is not likely to have an adverse effect on property values for the
homeowners along Meadowcliffe Drive. Conversely, the shoreline protection work is expected
to protect property values at the subject site.
7.1.5
Rate of Erosion in Ecosystem
Based on historic erosions, it is estimated that erosion will continue at an average rate of 1.2
metres per years until the lower bluff reaches a stable slope of 2.5: 1.0 (horizontal: vertical) and
the upper 30 metres obtains a stable slope of 1.5: 1 (horizontal: vertical). A buttress proposed
at the eastern extent of the project site will stabilize the slope to halt erosion affecting 2 and 10
Meadowcliffe Drive. The long-term stable slope crest position is illustrated in Figure 14 and
Figure 20.
Sediment Deposition Zones in Ecosystem
The Preferred Alternative will result in a minor adjustment to the plan shape of the fillet beach
once the western-most headland is constructed. Sand that is normally transported to the east
during southwest waves will not be transported back to the west during easterly waves for a
shadow zone adjacent to the headland. This will cause the fillet beach to extend in front of
Cudia Park to the western headland. That extended beach will be very narrow and perhaps
intermittent between the headland and the existing end of the beach. The overall effect on the
existing beach will not be noticeable.
Flood Risk in Ecosystem
The project will not affect the flood risk in the project area.
Slope Stability
Terraprobe (2006) calculated that once the toe is stabilized the lower section of the bluff will
obtain a stable slope of 2.5: 1.0 (h:v) and the upper 30 metres will obtain a stable slope of 1.5 :
1 (h:v). Overall the project is considered to have a net positive effect. A buttress proposed at
the eastern extent of the project site will stabilize the slope to halt erosion affecting 2 and 10
Meadowcliffe Drive.
Existing Structures/ Hazardous Lands / Hazardous Sites
The shoreline protection works will protect the toe of the Meadowcliffe bluff from wave action
which will aid in slowing down the rate of erosion thus providing protection of residential
structures located on the tableland. However, the shoreline protection is not a sufficient
remedial action to protect all of the residential structures along the slope crest. The long-term
slope crest of the most eastern section of the project area is predicted to be projected inland
by approximately 59 metres on average from the 2005 slope crest once the shoreline
protection is in place (Terraprobe, 2009). Over the long-term additional bank stabilization
works may be required to prevent the LTSSC from encroaching on the residential dwellings
located at 1, 2 and 10 Meadowcliffe Drive.
Hazardous Lands / Hazardous Sites
TRCA will continue to administer Ontario Regulation 166/06 to prohibit, regulate or require
permission for development within the area of defined erosion hazard as outlined in Figure 14.
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8.0
DESCRIPTION OF ALTERNATIVE CONSTRUCTION ACCESS
Construction of the Meadowcliffe Erosion Control Project will require delivery of considerable
volumes of fill, cobble, and armourstone to the project site. To ensure that delivery of
construction materials to the project site has the least impact on the environment and the
surrounding community TRCA considered all viable options. In all, five possible options were
identified.
8.1
Alternative 1 – Bluffers Park Access Route
Trucks delivering materials and equipment to the project site would follow Brimley Road South,
into Bluffers Park. Once in Bluffers Park, trucks would follow Bluffers Park Road to the eastern
parking lot. The northern most portion of the parking lot would be cordoned off and signed to
separate public use areas from the delivery route. A temporary 10 m wide haul road
constructed of rubble at an elevation of 2 m above the high water level would be built along the
back of the beach.
At the terminus of the beach, an area of shoreline measuring approximately 500 m long would
have to be extended lakeward via lakefilling to allow for extention of the haul road eastward to
the project site. To ensure worker safety, an operating set back of 20 m from the bluff face is
required. The area of lakefill required to accommodate the eastern most section of the haul
road is therefore estimated at 17,000 m2.
Figure 21. Alternative 1 – Bluffers Park Access Route.
Source: TRCA, 2008.
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8.2
Alternative 2 – Marine Access Route
The Marine Access Route requires the addition of a 200 m groyne to the proposed shore
protection design to obtain revised water depths to facilitate offloading of construction
materials. Trucks would deliver materials into Bluffers Park via Brimley Road South. Once in
Bluffers Park, trucks would offload materials on to barges at the boat launch. A portion of the
parking lot would be cordoned off and signed to separate public use areas from the delivery
route and offloading area. Loaded barges would then be used to transport materials eastward
to the constructed groyne for offloading at the western extent of the project site. Transfer of
materials by barge would have to be coordinated with ongoing construction works and in
accordance with calm weather conditions to ensure worker safety and prevent loss of
materials.
Figure 22. Alternative 2 – Marine Access Route.
8.3
Source: TRCA, 2008.
Alternative 3 – Guild Inn Access Route
Trucks delivering materials and equipment to the project site would follow either Galloway
Road or Morningside Avenue to the Guild Inn access road located on Guildwood Parkway.
Travelling south to the terminus of the Guild Inn access road, trucks would then travel west
along TRCA’s shoreline maintenance and service road to the project site. A narrow beach
located to the east of Bellamy Ravine would be replaced with a rubble revetment during
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construction of the Meadowcliffe shoreline protection to facilitate access. A temporary access
road and crossing would be required at Bellamy Ravine.
Figure 23. Alternative 3 – Guild Inn Access Route.
8.4
Source: TRCA, 2008.
Alternative 4 – Bellamy Ravine Access Route
From Kingston Road, trucks would travel south down Bellehaven Crescent and down the Doris
McCarthy Trail located in Bellamy Ravine. Upgrades to the trail surface and vegetation clearing
would be required to facilitate ongoing truck traffic. Re-grading of the southern extent of the
trail may be required to reduce safety risks. A crossing over the drainage swale at the bottom
of the ravine would also be required.
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Figure 24. Alternative 4 – Bellamy Ravine Access Route.
8.5
Source: TRCA, 2008.
Alternative 5 – Top Dumping
The top dumping alternative would require an access agreement with a private landowner
adjacent to the project site to permit the dumping of fill and aggregate materials over the bluff
crest to the project below. Truck traffic would travel to Meadowcliffe Drive via Pine Ridge Drive
to transport materials to the site.
9.0
EVALUATION OF ALTERNATIVE CONSTRUCTION ACCESS OPTIONS
Each of the five construction access options were evaluated against relevant environmental,
cultural and socioeconomic criteria, as outlined below, to determine the negative and positive
impacts of each. TRCA’s evaluation of potential impacts focused on the local study area which
is defined as the residential neighbourhood located south of Kingston Road.
Technical Considerations
• Slope stability
• Erosion
• Safety
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Natural Environment
• Terrestrial habitat
• Wildlife
• Aquatic habitat
• Area of Natural and Scientific Interest ie. geological significance
• Unique landforms ie. Bluffs
Socio-Economic Environment
• Public recreation
• Surrounding residential community
• Vistas and scenic views
Feasibility and Cost
• Capital and maintenance costs
• Impact on other projects
• Land requirements
9.1
Alternative 1 – Bluffers Park Access Route
Trucks traveling along Brimley Road South are expected to have minimal impact on
surrounding residential community as residences south of Kingston Road are limited to those
which back on to the east side of the road. The northern portion of the parking lot adjacent to
the East Beach would be closed to separate public use areas from the delivery route. This
would address potential safety concerns; however the amount of available parking for beach
goers would be reduced during active use of the access road. Noise and dust related to the
access road may also impact the beach users’ quality of experience.
A temporary 10 m wide haul road constructed of rubble at an elevation of 2 m above the high
water level would be built along the back of the beach. Siting of the haul road would have to
confirm that significant flora is protected, as the beach is known to support numerous locally
rare species. These species include Beach Pea (Lathyrus japonicus), Sea Rocket (Cakile
edentula), Oake’s Evening Primrose (Oenothera oakesiana), Wood Sage (Teucrium
canadense), and Wooly Sedge (Carex pellita). A large wetland was also recently constructed
by TRCA in 2008 to treat overland runoff and ground water seepage as part of a recent initiative
of the Mayor David Miller to improve recreational beaches. Construction of the access road
between the beach and wetland may impact drainage of the wetland into Lake Ontario and
disrupt associated wildlife use.
At the terminus of the beach, an area of shoreline measuring approximately 500 m long would
have to be extended lakeward via lakefilling to allow for extention of the haul road eastward to
the project site. To ensure worker safety, an operating set back of 20 m from the bluff face is
required. The area of lakefill required to accommodate the eastern most section of the haul
road is therefore estimated at 17,000 m2. The access road will take over 85 days to construct
at a cost of $250,000. Half the land required to build the road would also have to be acquired
from private landowners prior to construction. Furthermore the estimated 25,000 m3 of rubble
required to build the road would reduce the amount of available material required to complete
the planned shore protection at Meadowcliffe.
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Informal protection of the access road reduces shoreline erosion and thus impacts local
sediment sources that contribute to regional transport. Lakefilling adjacent to Cudia Park will
stabilize the Bluff, eliminating the unique cliff feature, and affecting Earth Science ANSI (1 of 3
sites selected to represent the geological history of the Bluffs), potentially restricting future
scientific study of Pleistocene Geology.
To mitigate the negative impacts associated with the lakefilling adjacent to Cudia Park the area
of lakefilled shoreline could be decommissioned following the delivery of the construction
materials to the project site. This would however likely double the cost associated with this
access route option.
Alternatively the access route could provide a waterfront trail connection between Bluffers Park
and Bellamy Ravine; however this option is inconsistent with the recommendations of the
Integrated Shoreline Management Plan. TRCA’s current waterfront plan, the Integrated
Shoreline Management Plan (ISMP 1996), provides a framework for evaluating and prioritizing
site-specific shoreline works, including natural heritage protection and regeneration, lakefilling,
private development and public recreation activities. The Plan places emphasis on protecting
the few remaining continuously eroding shore cliffs due to their provincial geological
significance and contribution to the regional identity. The ISMP states that this section of
shoreline should remain in a natural state because it represents one of the few unprotected and
natural shores of the Scarborough Bluffs. No major waterfront trail or public access was
recommended for this shoreline sector.
As none of the landowners to the west of the project site participated in the Class EA process,
lengthy negotiations are likely required to secure the riparian rights of the private lands located
between Bluffers Park and Meadowcliffe Drive. Furthermore, while several members of the
public noted interest in a waterfront trail connection between Bluffers Park and Bellamy Ravine,
this was not the primary focus of this EA. As part of TRCA’s long-term waterfront planning, staff
will continue to engage the public in discussions regarding a potential trail connection to
discuss the merits of this option.
9.2
Alternative 2 – Marine Access Route
The Marine Access Route requires construction of a 200 m groyne to facilitate offloading of
materials from barges at the western terminus of the project site. The groyne is valued at
approximately $1,000,000 and would take an estimated 40 days to construct. Additional costs
to the project are associated with additional delivery costs and restrictions on timing of delivery
that are incurred by using marine equipment.
In addition to the considerable increase in project costs, other negative impacts associated
with this access route include disruption of the eastward movement of sediment which would
result from construction of the groyne and influence on deposition adjacent to Cudia Park.
This increase in deposition is expected to eliminate the unique cliff feature, which will impact
the aesthetic nature of the shoreline and restrict future scientific study of Pleistocene Geology.
Delivery of construction materials by barge would significantly reduce local construction traffic
to and from the immediate project site; however barges would be loaded at Bluffers Park which
is located within the local community. Once in Bluffers Park, trucks would be offloaded to
barges at the boat launch. During this operation both the boat launch and parking lot would be
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closed for public use. As the use of marine equipment requires warm, calm weather, closure of
the boat launch and adjacent parking area would likely coincide with the boating season. The
potential for negative impacts on recreational boating and park use is therefore considerable.
Furthermore, the boat basin may require dredging to provide required depths for marine
equipment.
9.3
Alternative 3 – Guild Inn Access Route
The Guild Inn service road is located about 3.5 km east of the existing project site. To
construct a connection from the terminus of the existing shoreline access road to the
Meadowcliffe project site would take approximately 25 days at an estimated cost of $35,000.
Upon completion of the project restoration of the former beach would be required. The cost to
remove the rubble revetment and reinstate the sand/gravel beach is estimated at upwards of
$100,000. Extra material handling costs may also be incurred as a result of utilizing this
access route due to the distance trucks are required to travel along the shoreline service road
from Guild Inn. Truck traffic along the access route will restrict recreational use and may
temporarily displace wildlife when in use. The most significant impact related to utilizing this
access route is the disturbance to the residential community adjacent to the Guild Inn service
road entrance.
9.4
Alternative 4 – Bellamy Ravine Access Route
Use of the Doris McCarthy Trail located in Bellamy Ravine will require surface upgrades and
widening to accommodate truck traffic. TRCA recognizes the presence of provincially and
regionally uncommon plant species within Bellamy Ravine which may be impacted during
construction of the access road. Bellamy Ravine also provides refuge for songbirds during the
spring and fall migration. Truck traffic and clearing of vegetation is expected to have some
short-term impact on these birds and other wildlife which reside in the ravine.
Other considerations related to the use of this access route include worker safety as the road
would only be able to accommodate one lane of truck traffic. Truck movements would
therefore have to be controlled at the north and south entrance to prevent accidents. This may
cause traffic concerns along Kingston Road and Bellehaven Crescent as trucks may have to
enter queue before entering the access route.
Increased truck traffic, queuing vehicles and location of trucks in relation to neighbouring
private properties adjacent to the ravine have potential for considerable impact to the local
community. Property easements may also be required at top of ravine to facilitate truck
access.
Review of this option by TRCA engineering staff also determined that the steep nature of the
slope at the bottom of the ravine and potential for slope failures may place limitations on the
use of the existing trail for construction access during wet weather or winter conditions. A
subsequent study completed by Terraprobe in 2009 (see Appendix D) confirmed that lower
slope conditions in Bellamy Ravine are not sufficiently stable and safe to permit access by
heavy construction vehicles.
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9.5
Alternative 5 – Top Dumping
In the interest of exploring all available options TRCA reviewed the potential to utilize a top
dumping method to deliver construction materials to the site. This method has not been
utilized by TRCA in recent years due to the significant safety risk to staff, related to operating
equipment at the top of the unstable bluffs. The height and instability of the bluffs create
potential for sudden slope failures which places workers at undue risk. Slope failures will also
likely result in some of the delivered materials being buried, increasing cost related to recovery
or replacement of the affected material.
It is also expected that erosion generated by materials being dumped over the edge of the
bluffs would result in ongoing release of sediment into lake. Turbidity resulting from this
release of sediment is expected to have negative affects on fish and fish habitat.
Other impacts related to this option include disturbance to local residents caused by truck
traffic and noise of dumping of materials.
10.0
PREFERRED ACCESS ROUTE
The evaluation results as presented in Section 9.0 identified that the access route with the least
negative impacts is to utilize TRCA’s existing service road which provides shoreline access
from the Guild Inn. Impacts associated with this option largely relate to the distance trucks
would be required to travel at a low rate of speed along the shoreline and the cumulative
impact of increased truck traffic in the surrounding residential community. These impacts
however are temporary in nature. TRCA has worked with the community to address public
concerns related to this option to ensure that all potential impacts are mitigated.
10.1
Public Comments on Preferred Construction Access Route
The primary concerns raised by the public about the proposed construction access route via
the Guild Inn service road were the following:
•
•
•
•
•
•
Public accessibility to the shoreline during the periods of construction.
Pedestrian and vehicle safety with the increase truck traffic through the Guildwood
community.
Disturbance to existing wildlife and vegetation along the shoreline and Scarborough
bluffs.
The noise of the construction activity through the Guildwood community and along
TRCA service road.
The effects of the vibration from the construction activity on the stability of the bluffs.
The creation of dust from the construction activity.
TRCA has taken measures to address each of the concerns raised to either minimize or
mitigate any negative impacts potentially associated with the use of the proposed access route.
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A copy of TRCA letter to the GVCA and the newsletter to the public that outlines the mitigative
measures proposed by TRCA to address issues raised during the public consultation process
are included as Appendix C.
10.1.1 Public Accessibility
TRCA is aware that many members of the Guildwood community utilize the Guild Inn service
road to gain access to the shoreline. However, as the primary purpose of the service road is to
provide TRCA with vehicle and equipment access to the shoreline, TRCA must restrict public
access during periods of active operation in order to ensure public safety. While the service
road was not intended as a formal pedestrian trail, TRCA understands the importance of
maintaining this informal public use. As such TRCA is committed to allowing the public access
to the service road for recreational purposes on public holidays, weekday evenings (between
5:00 pm and 7:30 am) and weekends (from 4:30 pm on Friday to 7:30 am on Monday). TRCA
will also endeavour to minimize disruption to public use of the service road during warm
weather months from April to October. Moreover, TRCA will commit to provide the public with
formal notification of construction or maintenance activities to improve communication with the
community.
10.1.2 Guildwood Community Public Safety
The review of the comment forms revealed the Guildwood communities major concern was
public safety with the potential impact of increased truck traffic throughout the community
during the construction of the Meadowcliffe Drive Erosion Control Project. Since the public
meeting held to discuss the proposed access route, TRCA has completed a road traffic impact
study through the Guildwood Village to assess the potential risk to public safety. As part of this
study TRCA retained transportation planning firm iTrans to collect baseline information on
traffic volume and patterns along the proposed route and assess the type and degrees of
impacts resulting from the delivery of material via the Guild Inn service road.
The study was completed in two phases to be able to collect representative data during
different periods of traffic conditions (i.e. summer vs. post-summer). All the pedestrian and
vehicle data was collected at the intersections of Guildwood Parkway/ Livingston Road,
Navarre Crescent/TRCA construction driveway, and Guildwood Parkway/Galloway Road. For
Phase I of the study, the data was collected over a 2 week period in July 2009 during inactive
and active use of the Guild Inn service road for comparison purposes. Phase II of the study was
completed over a week period at the end of September 2009 to capture additional data when
school is in session and to reflect local residents return from summer holidays.
The results of the Phase I (summer conditions) indicate that TRCA truck traffic represents about
0.8 % of the peak hour (1:30 pm to 2: 30 pm) traffic and 1.0 % of the eight hour (7:30 am to
3:30 pm) traffic, which is not a conspicuous number in terms of traffic volumes. During Phase II
(post-summer conditions) the results indicate that there was a minimal increase of TRCA truck
traffic which represents 0.9% of the peak hour (8:30 am to 9:30 am).
The peak hours during the summer and post-summer conditions were observed at different
periods of the day. The peak hour of the summer conditions was from 1:30 pm to 2:30 pm
inferred to be the local community members commuting to the local market and the peak hour
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of post-summer conditions was from 8:30 am to 9:30 am inferred to be members of the
community commuting to and from work/school.
In general, the pedestrian traffic along Guildwood Parkway was significantly higher during the
summer conditions compared to the post-summer conditions with a magnitude of 201
pedestrians versus 97 pedestrians. During these periods the truck traffic slightly increases
from 3 TRCA trucks during the peak hour of the summer conditions to 4 TRCA trucks during
the peak hour of the post-summer conditions.
This study has concluded that TRCA truck traffic increases the local Guildwood Village traffic by
0 to 2%, which is not foreseen as a public safety concern to pedestrians. A copy of the Traffic
Impact Study completed by iTrans Consulting Inc. is contained in Appendix D.
TRCA will use the results of the traffic impact study in the development of an operation plan
that will seek to effectively avoid, minimize or mitigate any potential negative impacts
associated with the continued use of the Guild Inn service road. TRCA proposes that the
operation plan will prescribe the following:
•
•
•
All trucks contracted by TRCA to transport materials to the Meadowcliffe project site will
be provided a map with clearly identified inbound and outbound routes, operation
hours and safety protocols.
Trucks will be directed by TRCA to utilize Morningside Avenue as the inbound route to
the Guild Inn service road entrance located on Guildwood Parkway.
Trucks will be directed by TRCA to exit the Guild Inn service road westbound on
Guildwood Parkway to Kingston Road.
Based on the current level of funding for this project, construction activity will be intermittent
over the next five years. Working with members of the CLC and representatives from the GCVA
executive, TRCA will ensure that the operation plan outlines a material delivery schedule that
considers the availability of funding and the need to minimize disruption to the surrounding
community. TRCA will also work with the CLC and GVCA to maintain regular communication
with the community regarding the progress of construction.
10.1.3 Disturbance to Existing Vegetation and Wildlife
TRCA is committed to minimize the disturbance to the vegetation and wildlife. A review of the
proposed access route has determined that no vegetation will be impacted by utilizing the
existing Guild Inn and shoreline service roads. At the transition area between the project site
and Bellamy Ravine a grassy area, composed of early successional plant species will be
cleared to accommodate the access road. This area will be restored at a 3:1 ratio with a native
seed mix, as such the impact on existing vegetation is considered minimal and temporary in
nature. TRCA does however recognize that use of the shoreline service road may temporarily
disrupt wildlife use. This impact is related to truck noise and will be limited to active use
periods which are expected to be intermittent over the course of the construction period and
temporary in nature.
10.1.4 Noise
To diminish the potential for noise from construction activity, all construction trucks will meet
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manufacturer sound attenuation specifications; and the project site will be in compliance with
time prohibitions for delivery of materials and operation of construction equipment per the
Toronto Municipal Code, Chapter 591 and other applicable noise protocols.
10.1.5 Vibration
TRCA contacted an engineering firm with professional experience in vibration monitoring,
Terraprobe Limited, to comment on the effects of vibration on the stability of the bluffs in
relation to the proposed construction route. The firm stated that the vibration from the
construction would not have any significantly adverse impact on the stability of the
Scarborough Bluffs. At any time during construction if there is any question of the stability of
the bluffs due to the vibration generated by construction activity TRCA will respect the need for
an engineering firm to complete vibration monitoring.
A copy of the letter on vibration impact commented by Terraprobe Limited is contained in
Appendix D.
10.1.6 Dust
In order to minimize the amount of dust generated by construction, mud build up on the roads
surrounding the site will be removed by street sweepers when required and trucks transporting
earth fill to the site will be covered with a tarpaulin. Efforts will be taken to transport
construction materials to the site and stockpile them to avoid having to use the access roads
during dry summer months when dust problems are exacerbated. Dust polymers approved by
the Ministry of the Environment will be applied along TRCA’s service access road to minimize
dust generated by trucks during dry weather conditions. Furthermore, truck drivers will also be
reminded by the on-site construction supervisor of the City of Toronto’s anti-idling bylaw. By
taking these precautionary measures TRCA believes that the public’s concerns related to dust
can be addressed.
11.0
SUMMARY OF PUBLIC CONSULTATION
This section of the Environmental Study Report provides a summary of comments received
during the planning and design phases of the project, and a discussion of how these concerns
have been addressed.
11.1
Role of the Community Liaison Committee
The following information is provided from Conservation Ontario’s Class Environmental
Assessment for Remedial Flood and Erosion Control Projects (January 2002).
“In an effort to facilitate more on-going public involvement at the project
level, the Conservation Authority shall, based on its contact group
mailing lists and expressions of interest from the local landowners,
members of the general public, interest groups, or agencies, establish a
Community Liaison Committee (CLC) to assist the Authority by obtaining
additional public input concerning the planning and design process of
an individual flood and/or erosion control project, and to review
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information and provide input to the Conservation Authority throughout
the process. The Conservation Authority shall strive to ensure that the
membership of the CLC is representative of all views respecting a
proposed remedial and erosion control project. (Conservation Ontario,
2002).”
“As the name implies, the function of the CLC, in the Class EA process,
will be to assist the Conservation Authority to reach out and maintain
contact with community residents, groups, associations and
organizations. The CLC will provide direct input into the process. At the
end of the process, the entire committee will have been exposed to the
entire process, will have understood how decisions have been reached
and will have had their questions answered during the process.
To fulfill its function, the CLC will:
• Identify items of public concern with regard to the impact and design
of proposed erosion control alternatives;
• Provide direct input on these concerns to the Conservation Authority
to be utilized throughout the planning and design process;
• Co-host, with Authority Staff, meetings organized by the Authority to
facilitate the resolution of concerns relating to a proposed remedial
work;
• Review any Part II Order Requests made by members of the public
and attempt to resolve the issues of concern between the Part II Order
requesters and the Conservation Authority before the request gets
referred to the Minister of the Environment for a decision; and
• Where appropriate, submit an assessment to the Conservation
Authority, upon project completion, commenting on the effectiveness
of the Class EA process for meeting public concerns for the specific
project, and where relevant, identify possible improvements (pp.3637) (Conservation Ontario, 2002).”
More information regarding the CLC is described in the following section.
11.2
Public Notifications and Consultation
The following is a summary of all public notifications and the consultation process completed in
support of the Meadowcliffe Drive Erosion Control Project. Documents related to public
outreach component of this project; including all published notices, meeting materials and
minutes, and comment forms are included in Appendix C.
Comment forms were distributed by TRCA following each public consultation session to ensure
that an understanding of the project objectives and direction was maintained throughout the
planning process. The forms also provided a means of soliciting input into the planning and
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design phases of the project, and were utilized in the development of the alternative options
considered and in the selection and refinement of the preferred alternative. Written comments
ensured that ideas and concerns were investigated and addressed at meetings, facilitating
open dialogue between staff and the general public.
11.2.1 Notice of Intent
In accordance with the Class EA process, the first point of public contact occurred when the
Notice of Intent was published in the Scarborough Mirror on September 15, 2006. The Notice
of Intent was also delivered to the following:
•
•
•
•
•
•
•
TRCA staff with an interest in the project
City of Toronto staff with an interest in the project
Conservation Ontario
Councillor Brian Ashton, Ward 36 – Scarborough Southwest
Lorenzo Berardinetti, M.P.P., Scarborough Southwest
Ministry of the Environment
Ontario Heritage Trust
A Community Liaison Committee (CLC) was subsequently formed, which included the affected
landowners, TRCA staff and other individuals who expressed an interest in the project.
11.2.2 Community Liaison Committee Meeting #1
The first CLC meeting, held on October 11, 2006 at 1 Eastville Avenue, was attended by several
staff from TRCA, Councillor Brian Ashton, several local property owners, an employee from
Toronto Water, staff from Shoreplan Engineering Ltd., and staff from Terraprobe Limited.
Four alternative techniques utilized in shoreline stabilization project with similar conditions to
those found along the shoreline below Meadowcliffe Drive were presented to the attendees.
The four techniques presented were:
1.
2.
3.
4.
Segmented Breakwater Beach
Revetment
Headland/Groyne Beach
Boulder Berm
Additionally, the “Do Nothing” option was discussed. Examining this option is a required step
of the Class EA process, and is used as a tool to demonstrate the results of not undertaking
remedial works. Through the examination of the Do Nothing option it was illustrated that the
long-term, stable slope crest for this unprotected section of the shoreline would place
numerous homes, the road, and other public infrastructure at risk.
At the conclusion of the meeting, a comment form was distributed to the participants asking for
input into the next steps of the planning process for the project.
Based on the comment sheets received there was a strong preference for a Headland beach
system. Reasons cited for the preference include:
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•
•
•
•
Provides an attractive, diverse habitat for plants and wildlife.
Similar structure east of Bellamy Ravine appears to be quite effective at stopping toe
erosion.
It would be aesthetically pleasing.
Potential to improve terrestrial and fish habitat in long-term.
The documentation of this meeting is contained in Appendix C.
11.2.3 Community Liaison Committee Meeting #2
CLC meeting #2 was held on February 7, 2007 at 1 Eastville Avenue, and was attended by
several staff from TRCA, staff from Shoreplan Engineering Ltd., Councillor Brian Ashton, several
local property owners, representatives for Lorenzo Berardinetti, M.P.P., a representative from
the Ontario Heritage Trust, and a City of Toronto staff member.
Shoreplan Engineering Ltd. (Shoreplan) presented nine alternative design concepts, and
provided rough cost estimates for each of the proposed options. A comment form was
distributed to the CLC to provide feedback on each of the options presented, to select the
preferred design concept, and to assess the importance of the evaluation criteria for each of
the concepts presented.
It was communicated to the CLC members that the rating of the criteria would have an impact
on the overall evaluation of the preferred option. Further it was explained that the rating of
each individual criterion may not be held on par, based on project specific constraints. The
evaluation is based on the screening criteria mandated in the Class EA document
(Conservation Ontario, 2002).
In order to assess the relative importance of the evaluation criteria, CLC members were asked
to rank each criterion on a scale of 1 to 5, 5 being the most important, 1 being the least
important, NC being “no comment”. The results of the rankings from the five (5) returned
comment sheets are documented in Section 5.2.
As illustrated in Table 13 and Figure 19 the technical and engineering (e.g., rate of erosion,
sediment deposition, flood risk and slope stability) and physical (e.g., unique landforms, air
quality, existing transportation routes, noise and vibrations) criteria were considered to be of
greatest importance by the CLC members.
The results of the returned ranking forms also indicate that the preferred design concept
selected by the CLC members was the Headland Beach Concept (1a), which provides
protection to Meadowcliffe Drive only. Comments included on the forms included:
•
•
Headland Beach – Meadowcliffe Drive (Concept 1a) is the only concept considered to
be the most practical in terms of cost, property protection, and beach access for the
public.
Headland Beach – full site (Concept 1b) is effective but costly. The member has
reservations about implementing shoreline protection for the entire project limits since
the majority of the erosion is concentrated at the Meadowcliffe Drive shoreline.
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•
•
Groyne Retained Sand Beach – Pre-fill Beach (Concept 4c) is too expensive.
The shoreline from Bluffers Park to Port Union should be connected in order to facilitate
pedestrian recreational use and future TRCA shoreline protection construction or
maintenance.
The preferred alternative will include the following features:
•
•
•
•
•
A cobble beach retained by 4 headlands.
The end headlands will be constructed like “L” groynes, with armour stone along the
outside of the headlands.
The western-most headland has a small spur on its west side to help retain any sand
transported alongshore from the Bluffer’s Park beach.
The two central headlands will be constructed from shore but only the shore-parallel
component of those headlands will be armoured.
A buttress of earth, rock or rubble fill from the toe of slope to elevation 84 m, with an
inclination of 2.5:1 (H:V)
The documentation of this CLC meeting is contained in Appendix C.
11.2.4 Public Meeting #1
A public open house was held on May 9th, 2007 at the Scarborough Village Recreation Centre.
The purpose of the public open house was to invite the general public to view the preferred
alternative. The open house was advertised in the Scarborough Mirror on May 2nd, 2007 and
separate invitations were sent to each of the CLC members. There were approximately twentyseven (27) individuals in attendance at the open house.
The meeting consisted of an open discussion period with display boards illustrating the details
of the existing conditions and the preferred alternative, followed by a presentation by TRCA
staff, and Shoreplan Engineering that discussed the Class EA process, and provided the
attendees with the process and rationale used in the selection of the preferred alternative. A
comment form was distributed at the meeting asking attendees to provide their comments and
general thoughts on the preferred alternative. Five (5) completed comment sheets were
submitted, and 100% of respondents understood and agreed with the preferred alternative.
The documentation of this public open house is contained in Appendix C.
11.2.5 Public Meeting #2
A public information session was held at Sir Wilfred Laurier Collegiate Institute on January 14,
2009 to discuss past and present shoreline stabilization projects along the Lake Ontario
waterfront including Guildwood Parkway, Guild Inn and Meadowcliffe Drive.
The information session was advertised in the Scarborough Mirror on January 7th, 2009 and on
the Guildwood Village Community Association (GVCA) website. Furthermore, newsletters and
invitations were delivered to 600 area residents, GVCA, Ontario Heritage Trust, City of Toronto,
Shoreplan Engineering Limited, Councillor Brian Ashton, Councillor Paul Ainslie, and provincial
and federal government officials. There were approximately fifty (50) individuals in attendance
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at this meeting.
The meeting consisted of an open discussion and display board period followed by a
presentation by TRCA staff discussing the Meadowcliffe Drive Class EA. As part of the
presentation, a detailed analysis of the five main construction access options considered was
provided. Each route was thoroughly evaluated and discussed in relation to the natural
environment, technical consideration, socio-economic impacts, feasibility and cost.
The proposed preferred construction access route is through the Guildwood community,
accessing the shoreline by way of Guild Inn and traveling along the service road to the
Meadowcliffe sector. This service road has been owned and operated by TRCA for more than
25 years for vehicle and equipment access to TRCA’s shoreline erosion control project sites. A
comment form was distributed at the meeting asking attendees to provide their comments and
general thoughts on the preferred alternative, and on the proposed construction access route.
Twenty-three (23) completed comment forms were submitted to TRCA after the meeting. The
primary concerns identified in the comment forms and at the meeting were those pertaining to
the proposed construction access route via the Guildwood Community to access the
Meadowcliffe shoreline sector.
A hybrid construction access route was discussed during the session and many favourable
comments on this route were noted on the comment forms. Since the information session,
TRCA retained a geotechnical engineering firm to conduct a feasibility study to develop the
hybrid construction access route. The construction trucks would enter from the Guild Inn travel
along the shoreline service road to the project site and exit via Bellamy Ravine. The results of
the study concluded the lower slope conditions in Bellamy Ravine were not sufficiently stable
and safe to permit access by heavy construction vehicles. Based on these results the hybrid
option was eliminated as an alternative for construction access. A copy of the Bellamy Ravine
Slope Stability report completed by Terraprobe Limited is contained in Appendix D.
TRCA received a letter from the GVCA raising their concerns related to TRCA’s preferred
construction access related to increased truck traffic through the Guildwood community. TRCA
also received a letter from the Ontario Heritage Trust, the property owners of 1 Meadowcliffe
Drive. The Trust strongly supports the Guild Inn construction access route and objects to the
use of the Doris McCarthy Trail as an access option (also known as Alternative 4 - Bellamy
Ravine Access Route). The concerns noted on public comment forms about the proposed
construction access route through the Guildwood Community were similar to the concerns
raised by the GVCA. These concerns can be summarized as follows:
•
•
•
•
•
•
Public accessibility to the shoreline during the periods of construction.
Pedestrian and vehicle safety with the increase truck traffic through the Guildwood
community.
Disturbance of existing wildlife and vegetation along the shoreline and Scarborough
bluffs.
The noise of the construction activity through the Guildwood community and along
TRCA service road.
The effects of the vibration from the construction activity on the stability of the bluffs.
The creation of dust from the construction activity.
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11.2.6 Meetings with the Guildwood Village Community Association
TRCA held meetings with representatives of the GVCA and the local councillors on several
occasions to address the concerns associated with TRCA’s preferred construction access
route. TRCA has developed and presented measures to address each of the concerns raised
to either minimize or mitigate any negative impacts potentially associated with the use of the
proposed access route as outlined in Section 10.
11.2.7 Notice of Filing
The second public notification will occur when the Environmental Study Report is filed on
March 4, 2010. As per the requirements of Section 4.2 of the Class EA document, a Notice of
Filing shall be published in the same newspaper as the Notice of Intent, in this case the March
4, 2010 issue of the Scarborough Mirror, and shall be sent to all parties contacted in the first
notification process who expressed an interest in the remedial work and to Conservation
Ontario and the Ministry of the Environment. Copies of this report will be provided at the
Cliffcrest Public Library, Guildwood Library, TRCA’s website, and at TRCA’s Eastville office for
public review during the 30 day review period.
11.2.8 Notice of Project Approval
In the interest of good project management, a Notice of Project Approval and a Notice of
Project Completion shall be sent to all parties who expressed an interest in the project and to
Conservation Ontario.
12.0
MONITORING PROGRAM
Given the nature of coastal interventions over the past 50 years across North America, TRCA
anticipates that an adaptive management approach will be necessary, to allow modifications to
the overall design based on continued monitoring, evaluation of shoreline processes, slope
stability, International Joint Commission changes to Lake Ontario water level regulations and
long-term effects of climate change.
A program monitoring the performance of the shoreline protection works and beach is
proposed, and will consist of frequent visual inspection and formal surveys, with comparisons
being made to expected performance. Immediately following construction, the visual inspection
will be completed after each storm event. Surveys will be conducted annually until a period of
five years has passed, after which time inspection will be reduced to an appropriate frequency.
If a significant deviation from expected performance is noted during a visual inspection,
additional surveys will be undertaken immediately. If a survey detects a significant deviation
from expected performance, then remediation construction will be planned and implemented
immediately such that the shore connected headlands and the cobble beach sections meet
design performance criteria at all times.
The armour on the headlands will be inspected noting any significant displacement or
slumping of the armour. The armour layers will be placed, in the original construction, in a
specific placement such that the sub-armour layers cannot move through the main armour. Any
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displacement of the armour layer that exposes the sub-armour will be noted and repaired.
Slumping of the armour layer may indicate that the toe protection has moved or has been
undercut. If slumping is noted, the toe protection will be inspected, and surveyed to detect any
undercutting.
Some overtopping of the headland sections is expected. Inspections will include looking for
dislodged armour on top and on the inshore side of the headlands, and eroded material
inshore of the revetment. Suitable remedial construction will be planned and completed
immediately such that the headlands and revetments maintain design integrity.
Offshore profiles of the lake bottom will be recorded to detect any downcutting of the
foreshore, and /or any undercutting of the toe protection of the headlands and revetment
sections. Surveys will be undertaken once every 3 to 5 years as required.
Ongoing monitoring of the slope crest will also be required to confirm slope recession rates
and the projected LTSSC. This data will confirm the need and timing of future works which
may include construction of a slope buttress to reduce the severity of ongoing slope recession.
13.0
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Meadowcliffe Drive Erosion Control Project

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