Topcliff Avenue Erosion Control and Slope Stabilization Project

Toronto and Region Conservation Authority (TRCA) has proposed to undertake remedial flood and erosion control works behind Topcliff Avenue to provide long-term protection to private property from the hazards of erosion and slope instability.

Project Location

The project is located in the City of Toronto, near the intersection of Finch Avenue West and Jane Street.

Learn More About the Project

Project Background

This site was first identified to TRCA following reports of a slope failure that occurred after the July 8, 2013 severe weather event. Erosion and slope instability issues behind Topcliff Avenue are creating a hazard to private properties located at the top of slope.

A slope failure occurred behind the property seen at the top of slope following the July 8, 2013 severe weather event. This property is at long-term risk from erosion and slope stability hazards. Source: TRCA, 2019.
Garbage and debris jams within the Black Creek tributary channel located at the bottom of slope below Topcliff Avenue are causing flooding and creating additional erosion concerns for properties located at the top of slope. Source: TRCA, 2019.

This project is being planned in accordance with Conservation Ontario’s Class Environmental Assessment for Remedial Flood and Erosion Control Projects (amended 2013) (Class EA). The Class EA establishes a planning and approval process for a variety of projects that may be carried out by Conservation Authorities, including procedures and environmental planning principles for Conservation Authorities to follow to plan, design, evaluate, implement and monitor a project.

The below figure illustrates the Class EA planning process.

Class Environmental Assessment project planning process
Overview of the Class Environmental Assessment process.

Stakeholders will be invited to participate and provide input during various planning stages of the project. TRCA will coordinate these consultation opportunities and post updates to this web page.

The following alternative solutions were developed and evaluated by TRCA as part of the Class EA process for the project:

Slope Stabilization Alternatives:

Alternative 1 – Do Nothing

Alternative 2 – Improve drainage, minor earthworks and surficial erosion protection

Alternative 3 – Soil nail system

Alternative 4 Reinforced Soil Slope (RSS) system or Mechanically Stabilized Earth (MSE) structure

Black Creek Tributary Channel Alternatives:

Alternative 0 – Do Nothing

Alternative 1 – Channel realignment, decommission secondary channel formations

Alternative 2 – Channel improvements with armourstone wall bank protection

The results of the Class EA evaluation led to the identification of Slope Stabilization Alternative 4: Mechanically Stabilized Earth (MSE) Structure and Channel Alternative #2: Channel improvements with armourstone wall bank protection as the combined preferred alternative solution to address erosion and slope stability hazards within the project area. The following is a rendered image of what the preferred solution could look like below Topcliff Avenue.

This image has been rendered to represent what the combined preferred slope stabilization and erosion control solution could look like behind Topcliff Avenue. Source: TRCA, 2020.

Scope of Work

The proposed scope of work for this project includes stabilizing the valley wall behind Topcliff Avenue and completing erosion control works along the base of slope to ensure long-term stability and provide protection to residential properties located at the top of slope.

Throughout 2023, TRCA intends to:

  • Obtain detailed designs for the slope stabilization and erosion control works based on the preferred alternative solution identified in the Class EA
  • Initiate obtaining all necessary permits, approvals, and agreements
  • Tentatively begin construction of the slope stabilization and erosion control works pending the completion of permits, approvals, agreements, and detailed designs

Construction Information

TRCA is currently in the planning stages for this project. Construction information will be posted following completion of all planning activities.

Public Notices

Notice of Intent (NOI)
TRCA formally initiated this project in 2020 through the issuance of a NOI. The NOI was published in the North York Mirror on February 13, 2020 to inform community members of the project.

Notice of Filing (NOF)
On January 8, 2020, TRCA circulated the NOF to interested stakeholders to notify them that the Class EA Project Plan was filed for a 60-day public review period. All interested persons were invited to review the Class EA Project Plan and provide written comments to TRCA. Written comments had to be submitted by March 9, 2021.

TRCA’s Project Plan can be viewed using the following link: Topcliff Avenue Erosion Control and Slope Stabilization Project – Class EA Project Plan

Notice of Project Approval (NOA)
On March 29, 2021, TRCA circulated the NOA to interested stakeholders to notify them that no concerns regarding the project were raised during the 60-day Class EA public review period. As no concerns were raised, TRCA intends to proceed with developing detailed designs of the preferred alternative solution and obtain the necessary permits and approvals required for construction.

Notice of Construction (NOC)
Following completion of planning activities, TRCA will distribute a Notice of Construction to notify the local community and project stakeholders of the project’s construction timeline.

Progress Updates


  • TRCA, in conjunction with its engineering consultants, developed conceptual alternative solutions to address slope stability and erosion hazards affecting private properties along Topcliff Avenue
  • TRCA evaluated conceptual alternatives to identify the preferred alternative solution
  • TRCA issued a stakeholder engagement package to interested parties to solicit feedback and comments on TRCA’s identified preferred alternative solution
  • TRCA drafted the Class EA Project Plan


  • TRCA issued the Class EA Project Plan. No concerns regarding TRCA’s proposed works were received and the Project Plan was successfully approved.


  • Consulted the affected landowners to review TRCA’s proposed works and refine the extent of TRCA’s intended work limits

Contact Us

For more information regarding this project, please contact Courtney Munro, Project Manager:

Courtney Munro, Project Manager
Erosion Risk Management
(647) 426-4492