STAFF REPORT
January 28, 2000
To: Toronto Community Council
From: Acting Commissioner of Urban Development Services
Subject: Rezoning of the lands within and abutting the Vale of Avoca Ravine and currently covered by Interim Control
By-law No. 44-1998 as amended by By-law No. 88-1999
(Midtown)
Purpose:
This report recommends that the lands in and within 10 metres of the Vale of Avoca Ravine be subject to a restrictive
exception which would implement a "Ravine Impact Area." The line defining the "Ravine Impact Area" would be
consistent with the current line in the Official Plan defining the boundary of the Vale of Avoca Ravine.
Financial Implications and Impact Statement:
There are no financial implications resulting from the adoption of this report.
Recommendations:
It is recommended that:
1. City Council amend Section 12(2) RESTRICTIVE EXCEPTIONS of the Zoning By-law 438-86, as amended, for the
former City of Toronto by:
(a) adding a ARavine Impact Area@ and stating that no person shall, on a lot which is located wholly or partially within 10
metres of the Ravine Impact Area of the Vale of Avoca Ravine, or within the Vale of Avoca Ravine, use or erect a
building, structure or an addition for any purpose, other than those required for flood and/or erosion protection or those
related to federal, provincial or municipal infrastructure, unless the building, structure or addition is set back 10 metres
from the Ravine Impact Area, except that:
(i) an addition can be made to a building or structure existing at the time of the passing of this by-law that is within 10
metres of the Ravine Impact Area, provided the proposed addition is no closer to the Ravine than any existing wall of the
existing building or structure;
(ii) any building or structure existing within 10 metres of the Ravine Impact Area at the time of the passing of this by-law
may be replaced, provided that the replacement building or structure does not have any greater floor area or height and is in
the same position relative to the lot lines as the building or structure it replaces; and
(iii) the pair of semi-detached houses allowed by the decision of the Ontario Municipal Board Order (File No. C990085,
V990146, and PL990310) and located at the lands currently known as 40 Summerhill Gardens may be constructed;
2. the City Solicitor be authorized to prepare and submit to Council the necessary by-laws; and
3. the Commissioner of Urban Development Services, in consultation with the Commissioner of Works and Emergency
Services, be requested to report back on changes to the designation of Vale of Avoca Ravine to ensure that the designated
Ravine more closely follows the true top-of-bank.
Background:
On July 14, 1997, Council of the former City of Toronto adopted By-law 1997-0369 imposing a Ravine Impact Boundary
(or Area) for the lands abutting the Park Drive Ravine. These amendments to By-law 438-86 for the Park Drive Ravine
introduced restrictions on the use and development of the lands generally within the first 10 metres from the boundary of
the Park Drive Ravine and within the Ravine. As a result of the introduction of this By-law, there were appeals pertaining
to two specific properties. However, it should be noted that this by-law was approved by the Ontario Municipal Board
(OMB), as it applied to the balance of the approximately 170 properties affected by this change to the By-law.
In accordance with the recommendations of Clause 7 of the Land Use Committee Report 10, adopted by City Council on
July 14, 1997, I also was requested to report back on a process and timetable for developing ARavine Impact Boundaries@
for ravine areas throughout the former City of Toronto. In partial response to this request, this Department=s report, of May
25, 1999, respecting the Nordheimer Ravine, recommended similar controls to those applicable to the Park Drive Ravine
be applied within the Ravine and for the lands within 10 metres of the Nordheimer Ravine. These controls were enacted
with the adoption of By-law No. 404-1999 on July 8, 1999. There were no appeals of the adoption of this by-law.
On March 4, 5 and 6, 1998, nine months after the adoption of By-law 1997-0369 pertaining to the Park Drive Ravine,
Council for the former City of Toronto adopted By-law No. 44-1998 (see Map 1) which had the effect of prohibiting for a
period of one year, the erection of any building or structure within 10 metres of the Vale of Avoca Ravine. Subsequently, at
its meeting on March 4, 1999, Council of the City of Toronto adopted By-law No. 88-1999, which served to extend the
Interim Control By-law applying to these lands for a further period of one year.
At the time of the passing of the Interim Control By-law for the lands abutting the Vale of Avoca Ravine, I noted in my
report that there were active Committee of Adjustment applications to allow the construction of a pair of semi-detached
houses at 40 Summerhill Gardens. The requested variance and severance applications to allow the construction of these
houses was approved (subject to a number of conditions) by the OMB in its decision/order issued on October 6, 1999. City
Council in adopting the Interim Control By-law (By-law 44-1998) also requested me to undertake a review of the land use
policies appropriate for the lands within and abutting the boundary of the Vale of Avoca Ravine.
The currently proposed By-law amendment for the lands covered by the Interim Control By-law would:
(i) be consistent with the environmental policies of the Official Plan;
(ii) be complementary to the Toronto and Region Conservation Authority's fill and top-of-bank regulations;
(iii) have appropriate regard for the relevant policies of the Provincial Policy Statement regarding significant valley lands;
and
(iv) be consistent with the policies enacted for the lands generally abutting the Park Drive and Nordheimer Ravines.
This report is based on the findings of a study approved by Council of the former City of Toronto pertaining to the Park
Drive Ravine which found that privately held ravine lands can contribute to the sustainability and diversity of the ravine, as
long as an appropriate mechanism is in place to regulate the position of buildings and related development on any given
lot. The adoption of the recommended regulations will ensure that such a mechanism is in place respecting the lands
abutting the entire Vale of Avoca Ravine. The report further recommends that a subsequent study be undertaken to amend
the Official Plan designation of the Vale of Avoca Ravine to more closely relate the designation of the edge of the Ravine
to the existing top-of-bank.
Comments:
1. Location
The Ravine generally runs from the north end of the Park Drive Ravine and the Canadian Pacific Railway bridge on the
south to the Mount Pleasant Cemetery on the north.
2. Planning Considerations
2.1 Character of the Ravine
Toronto=s ravines are one of the most significant physical features of the City and were important in determining the
structure of the City. They continue to play an important role within the City as part of the ecosystem, as a major feature of
the drainage system within the City and as areas of natural amenity and recreation. During the development of the City,
roads generally bypassed the ravines, streams were allowed to continue to run through them and development generally
was not undertaken within the ravines. Today, however, quality urban land is scarce and due to their amenity, lots abutting
or within the ravines are highly marketable for residential development. These characteristics, coupled with current
engineering techniques which can overcome many of the physical constraints to building on, or adjacent to, steep slopes,
make the ravines more vulnerable to development.
The designated Vale of Avoca Ravine continues at its southern end into the Park Drive Ravine. The Ravine is
characterized by steep, heavily treed slopes and a relatively narrow, but partially open valley floor. The original streambed
within the Ravine has been buried to the north of the Ravine and also further south within the Park Drive Ravine as it
traverses in a southerly and easterly direction into the Don River. Along the western face of the Ravine, generally below
the Rosehill Reservoir, there has been a significant slippage of the Ravine slope. This indicates the potential instability of
ravine banks, particularly if care is not taken respecting the introduction of development, recreation facilities and the
management of native vegetation within and abutting the Ravine.
The vegetation of the ravines plays an important role in absorbing carbon dioxide and improving air quality. In addition,
the vegetation within the ravines absorbs significant amounts of urban noise, giving the surrounding areas a sense of calm
and quietness. This is especially evident at the bottom of the ravines where the steep ravine walls create a natural barrier to
urban sounds. This noise buffering capability is eroded as development encroaches into the ravines and development starts
to generate its own sounds.
In general, it is estimated that while the majority of the plant species documented in the Vale of Avoca Ravine are native to
the area, there are significant intrusions of Manitoba maple, Norway maple, Siberian elm and other non-native species
which tend to reduce the biodiversity and the richness of the overall species mix. A large portion of the Ravine bottom has
been cleared over the years as a result of various construction activities, including the construction of the TTC subway. As
further development encroaches into the Ravine, there is greater potential for slope failure, erosion of topsoils, the
introduction of retaining walls and the replacement of native species with invasive species. The loss of natural vegetation
in the Ravine also has a significant negative impact on wildlife habitat.
2.2 Erosion Control and Protection at the Top-of-Bank
The encroachment of development close to the top-of-bank has historically led to problems with erosion. The causes of
such erosion can be traced to increased runoff, dumping of garden refuse on the ravine slopes with the resulting destruction
of existing vegetation, and increased pedestrian traffic on the ravine slopes. As well, some erosion occurs around the bases
of bridges and along retaining walls built to extend rear yards abutting the ravine.
If this area were being subdivided today (rather than in the early part of the 1900's), in accordance with principles of sound
ecological planning and best management practices, it would be likely that development would not be permitted so close to
the top-of-bank of the original landform of the Ravine. More likely, a buffer zone would have been required that would
provide effective protection of the forest edge from the effects of wind and sun exposure, as well as to protect against
undue loading of the top-of- bank and diversion of ground water. Due to the age of the development in the area, however,
this level of protection and stewardship has not generally been practised. This has left this Ravine subject to considerable
urban stress similar to many other ravines within the City.
2.3 Urban Structure
The Vale of Avoca Ravine plays a significant role in the network of ravines within the City and is the northerly extension
of the Park Drive Ravine running north from the Canadian Pacific Railway bridge. The Ravine remains an important
natural open space and landscape within the urban environment and significantly adds to the quality of urban life.
The Ravine also provides a significant recreational resource for jogging, walking, cycling, tobogganing and other passive
recreational activities. In most cases, the existing residential dwellings on top of the ravine slopes are set back a reasonable
distance and masked by substantial vegetation. Such setbacks help to ensure that the scenic quality of the ravine is
maintained, as well as the stability of the ravine slopes.
The Official Plan addresses the issues of managing and preserving our natural heritage and ravine resources. As these
resources are limited within the context of urban life and vulnerable, it is appropriate that land management practices and
responsible land stewardship should be practised systematically to sustain the ravine system for future generations.
2.4 Current Processes for Regulating Development
Development regulation is primarily the function of the General Zoning By-law 438-86 and other site-specific by-laws
which serve to implement the policies of the Official Plan. Development within any defined ravine area is also subject to
Ravine Control (as defined in Chapter 276, Ravines of the former City of Toronto=s Municipal Code) and Site Plan
Approval. Other relevant policies are contained in the Toronto and Region Conservation Authority policies, the former
Metropolitan Toronto Official Plan and in the Provincial Policy Statement.
(a) Provincial Policy Statement
The Provincial Policy Statement came into effect on May 22, 1996. Ravines are not specifically defined in the Provincial
Policy Statement, but significant valley lands are classified as Natural Heritage features.
The Provincial Policy Statement (Policy 2.3) recognizes all valley lands within the area including Toronto as significant, as
they may constitute the only remaining natural areas in the municipality. These valley lands can form the basis for a natural
heritage system within the planning area. The Provincial Policy Statement also suggests the provision of a 50 metre buffer
for significant valley lands. The 10 metre buffer recommended by this report is a compromise between that recommended
in the Provincial Policy Statement and the recognition of the mature level of development within the City.
(b) The former Metropolitan Toronto Official Plan
The Vale of Avoca Ravine is within the Metropolitan Green Space System identified in the former Metropolitan Toronto
Official Plan (Metroplan). The policies in Metroplan seek to achieve the Metropolitan Green Space System through, among
other things, participation in initiatives for the protection and regeneration of significant natural areas. Significant natural
areas include, but are not limited to, sensitive and ecologically fragile areas and aquatic systems, and terrestrial habitats, as
identified by the Province, the TRCA and/or a Municipality. Such areas may include: ravines, wetlands, wood lots,
environmentally significant areas, areas of natural and scientific interest, valley land impact zones, environmental impact
zones and waterfront impact zones.
The policies in Metroplan also state that no new buildings or structures, other than replacements, minor extensions or
accessory structures are to be permitted within ravines or within a minimum of 10 metres from the edge of significant
natural areas, where these extend beyond the ravine slopes; except where the Area Municipality is satisfied, after
consulting with Metro and the TRCA, that the proposal does not detract from the objectives of the Plan and is in
accordance with policies in Metroplan.
(c) The former City of Toronto Official Plan
In 1981, Council of the former City of Toronto adopted Official Plan Amendment 165 by By-law 245-81, designating the
lands within the Vale of Avoca Ravine as a Ravine. The delineation of the boundaries of the Ravine are incorporated in
Appendix >A= (Ravine Maps) of the Plan.
The policies generally stated throughout Section 2.3 of the Plan direct Council to protect and enhance Natural Areas,
Environmentally Significant Areas, Ravines and the natural Lake Ontario shoreline. Section 2.4 of the Plan further deals
with issues pertaining to development in and abutting ravines and sets criteria for review if development is proposed within
ravine areas. More specifically Section 2.48 of the plan recognizes that development adjacent to ravines has potential for
significant impact upon the ravines and encourages the establishment of Aa buffer zone at least 10 metres adjacent to the
Ravine, Natural Area or Environmentally Significant Area within which all development is to be discouraged, and where
10 metres is clearly impractical, provide as large a setback from the boundary of the Ravine, Natural Area or
Environmentally Significant Area as is possible@. Section 2.54 also addresses the issue of slope stability as it affects the
safety of built structures and their occupants. These sections of the Plan suggest that Council should address the issues of
the protection and enhancement of these areas.
(d) The former City of Toronto=s Zoning By-law (438-86, as amended)
The Zoning By-law can be used to ensure that development is set back from a designated ravine. At the present time,
however, there are no specific regulations in the General Zoning By-law restricting development within ravines. With the
exception of the lands within and abutting the Nordheimer and Park Drive Ravines, the process of regulating development
within ravines has been undertaken by way of the designation of the Ravines within the Official Plan in concert with the
corresponding regulations found in Chapter 276 of the former City of Toronto Municipal Code.
(e) City of Toronto Act and Ravine Control By-law
In 1971, The City of Toronto Act was enacted giving the City legislative powers to regulate ravine preservation by way of
by-laws. The former City designated its first Ravine in 1979, however, it was not until 1981 that it enacted By-law 245-81,
designating the Vale of Avoca Ravine limits. In 1994, the former City of Toronto passed By-law 1994-0751, which
incorporated the Ravine Control By-law into the City=s Municipal Code, under Chapter 276 (Ravines). The Code currently
requires Council consent for any development, change of grade or removal of vegetation within Ravines and also defines
certain exemptions. Lands which are subject to the Ravine Control process are only those lands wholly located within the
Ravine boundaries as identified in Chapter 276. It should be noted that Chapter 331 (Trees) of the former City of Toronto
Municipal Code does not apply to vegetation within designated Ravines.
In situations where consent of Council is required under Chapter 276 of the Code, an application is filed with Urban
Development Services and distributed to other civic departments for comment. Once a satisfactory proposal is achieved,
recommendations are presented to the Toronto Community Council and City Council for approval. If approved, the City
Solicitor is usually directed to prepare a Ravine Control Agreement.
(f) Site Plan Control
Pursuant to Chapter 165, Article III of the Municipal Code, the proponent of any development within a designated Ravine
is required to obtain Site Plan Approval prior to being able to obtain a building permit. This requirement allows the City to
fully regulate all details of the development and to ensure that appropriate landscaping is undertaken, including all aspects
related to grading, drainage and the definition of suitable plant material.
(g) Toronto and Region Conservation Authority
In addition to the municipal approval process, there are two regulations that the Toronto and Region Conservation
Authority (TRCA) applies to development proposals within and adjacent to ravines. The first regulation is Ontario
Regulation 158 under the Conservation Authority Act which regulates the following:
(i) placement of fill within Fill Regulated Areas;
(ii) the building or renovation of structures within a flood plain; and
(iii) the alteration of a watercourse.
Most lands that back onto a ravine are considered by the TRCA to be within a Fill Regulated Area under Ontario
Regulation 158. The TRCA must approve by permit any placing of fill, construction of any sort (e.g. swimming pool,
greenhouse, fencing, etc.), renovation, addition or alteration to an existing building and alteration to a watercourse. The
intent of the Regulation is to prevent development that could lead to damage by floods or erosion and to protect the public.
The second regulation is the TRCA=s Valley and Stream Corridor Management Program (VSCMP) which was put in place
in 1994. The TRCA=s VSCMP governs the way development is to occur within ravines and aims to protect and
rehabilitate ravine corridor landforms, features and functions while being sensitive to development opportunities. The
intent of the Authority=s VSCMP is to prevent new development that would introduce risk to life and property associated
with flooding, erosion and slope stability and/or is not compatible with the protection and rehabilitation of surrounding
natural features and functions. In order to afford some protection to a ravine, the TRCA prescribes a minimum 10 metre
setback from the stable or predicted long-term stable top-of-bank.
2.5 Effectiveness of Current Land Use Regulations
From a planning perspective, Toronto=s ravines are a fundamental feature of the City=s infrastructure and a significant
determinant in the form of the development within the City. They also represent a resource and an amenity which cannot be
recreated or replaced. Accordingly, it is appropriate that the Vale of Avoca Ravine be protected through the
implementation of a buffer zone adjacent to the designated Ravine to ensure the stability of the Ravine edge and the
maintenance of a naturally vegetated area adjacent to the Ravine.
With the exception of the Nordheimer and Park Drive Ravines, at present the former City of Toronto Zoning By-law does
not implement the policies of the Official Plan to encourage at least a 10 metre setback for development proposals adjacent
to the Vale of Avoca Ravine, or as large a setback as possible where a 10 m setback is impractical. This is a Aregulatory
gap@ in the By-law, given the intent of the Official Plan to preserve and enhance the Ravine system.
2.6 Development Adjacent to the Vale of Avoca Ravine
The majority of the 64 properties abutting the Vale of Avoca Ravine are developed with residential buildings within the
relatively flat tableland portion of the site and with varying amounts of their rear yards reaching into the Ravine slope (see
Map 2). This tableland has provided a suitable area for building, while the sloped rear yards have provided a desirable,
wooded slope providing significant privacy. This has resulted in a pattern of low density development which respects the
natural characteristics of the Ravine.
Most buildings on lots abutting the Ravine have been placed well above any areas of significant slope to ensure slope
stability and also to ensure that the scenic value of the Ravine is not compromised by development perched on the edge of
the Ravine. In certain instances, however, the pressures of development have pushed this traditional pattern of the
construction of homes and accessory uses to and beyond the true edge of ravine slopes. There is a need to reassess the
actual defined limit of the Ravine and I am recommending that further study be undertaken to review and redefine the edge
of the designated Ravine to ensure that it is co-terminus with the top-of-bank.
It should also be noted that the original Ravine boundary was defined based on the best information available about the
actual top-of-bank, having appropriate regard for the presence of existing buildings and other changes made to the Ravine
over time. The line was plotted and dimensioned to be placed in the Ravine By-law (now Chapter 276 of the former City of
Toronto Municipal Code). However, it is clear that the line is an approximate representation of the actual top-of-bank.
Accordingly, there may be circumstances where it is appropriate to vary the line based on the findings of environmental
analysis and survey.
Conclusions:
Having regard for the City=s Official Plan policies respecting the protection of the ravine system, this report concludes that
the City=s Zoning By-law needs to be amended to:
- provide greater protection of the natural heritage features of the Vale of Avoca Ravine;
- maintain its visual and scenic characteristics; and
- minimize the hazardous impact that development may have on the stability of ravine slopes.
It is recommended that the Zoning By-law be amended to indicate those areas of land within and abutting the Vale of
Avoca Ravine where residential development is not permitted. Specifically, it is recommended that the former City of
Toronto=s General Zoning By-law (Section 12 (2)) be amended to identify a ARavine Impact Area@ for the Vale of Avoca
Ravine and to require that all new development be set back not less than 10 metres from the currently designated Ravine.
This 10 metre setback should help to ensure that there is an appropriate physical relationship between new residential
development and the designated Ravine. The line defining the ARavine Impact Area@ would be consistent with the
current line defining the boundary of the Vale of Avoca Ravine. However, if a property owner can demonstrate by way of a
physical survey, vegetation analysis and restoration plan, as well as an accompanying soils analysis that the outside
boundary of the Ravine Impact Area is actually farther away from the top-of-bank than defined in the Zoning By-law, then
it would be appropriate to grant a variance from the line to allow development to proceed. Such variances should only be
granted after careful study and assessment, including corroborating documentation.
So as not to unreasonably impact existing development, which in many cases was constructed prior to the evolution of
environmental policy through the 1960's, it is recommended that an exception be provided in the Zoning By-law
amendment for existing buildings which are currently closer to the top-of-bank than the minimum 10 metre setback
recommended. For example, if a building currently is only 5 metres from the defined Ravine, it is recommended that
additions be permitted to that building so long as the addition is no closer to the Ravine than the original building. The
addition would have to comply with all other applicable laws.
If a property owner wishes to undertake other development not specifiically allowed by any of the exceptions to the By-law
and can demonstrate by way of a physical survey, vegetation analysis and restoration plan, as well as an accompanying
soils analysis that the outside boundary of the Ravine Impact Area is actually farther away from the top-of-bank than
defined in the Zoning By-law, then it would be appropriate to grant a variance from the line to allow development to
proceed. Such variances should only be granted after careful study and assessment, including corroborating documentation.
The proposed pair of semi-detached houses at 40 Summerhill Gardens should also be exempted from the recommended
restrictions of the proposed By-law, as this development has been the subject of significant review and has been allowed by
the Ontario Municipal Board's Decision/Order No. 1835, dated October 6, 1999.
As exceptions related to existing development and additions to such development are contemplated by the proposed
By-law amendment, this amendment should not have a significant negative impact on maintaining or adding to existing
residential buildings. Non-exempt structures proposed inside the Ravine would require consent, site plan approval and
variances/rezoning. Non-exempt development within 10 metres would require variances/rezoning. Again, such approvals
should only be granted after careful study and assessment. Over time, as buildings are redeveloped, the required 10 metre
setback will ensure that all new development is appropriately set back and will create a more sustainable form of
development adjacent to the Ravine edge.
Contact:
Angus Cranston
Telephone: 392-0425
Fax: 392-1330
E-Mail: acransto@toronto.ca
Beate Bowron
Director, Community Planning, South District
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List of Attachments:
Maps (2)