Toronto and Region Conservation Authority (TRCA) has proposed to undertake remedial works in the stream valley corridor behind Clarinda Drive, in the City of Toronto. The purpose of this work is to protect private properties and municipal sewer infrastructure from valley slope instability related to erosion hazards within a tributary of the East Don River.
Project Location
The project area is located in a City of Toronto and TRCA owned valley corridor northwest of the intersection of Sheppard Avenue East and Leslie Street within the Blue Ridge Park public greenspace. A tributary of the East Don River is located within the valley behind Clarinda Drive.
The watercourse within the study area was divided into two Reaches based on channel gradient, form, and dominant geomorphic processes. The upstream Reach 1 spans from the Blue Ridge Road stormwater outfall for 205 m downstream. Reach 2 extends a further 170 m downstream of Reach 1.
Learn More About the Project
Project Background
Concerns regarding riverine and valley slope erosion behind Clarinda Drive were first identified to TRCA staff in 2009. Accelerated erosion and gullying were observed at this site related to the July 8, 2013 severe weather event. This storm resulted in several slope failures behind Clarinda Drive as well as damage to private residential properties at the top of the slope. Further inspection and investigative assessments of the Project site have revealed ongoing erosion issues within the channel including risk to municipal sanitary infrastructure from channel erosion.
TRCA undertook various investigations to determine the extent of risk to essential structures and infrastructure in this area over the long term from erosion and slope instability hazards. Based on the results of these investigations, it was determined that private residential dwellings, as well as City of Toronto owned sanitary infrastructure, were at risk from the hazards of erosion and slope instability should no remedial works be undertaken.
In order to address this risk, TRCA initiated the East Don River behind Clarinda Drive Erosion Control and Slope Stabilization Project (the “Project”) to provide long-term, low maintenance protection to at-risk essential structures and infrastructure adjacent to and within the project area.
TRCA has advanced detailed designs for Reach 1 and is planning construction to start September 2023. TRCA’s Erosion Hazard Monitoring Team will continue to monitor Reach 2, while this section of the Project remains on-hold pending results from the City of Toronto’s Newtonbrook & Blue Ridge Creeks Geomorphic Systems Master Plan.
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 process is the approved planning approach for this type of work. The following diagram provides an overview of the Class EA process.
The following alternative solutions were developed for Reach 1 and were evaluated as part of the Class EA process for the Project. As part of the Class EA process, a ‘Do Nothing’ alternative was considered:
Reach 1:
‘Do Nothing’ Alternative
Alternative 1 – Bank and Bed Protection and Upper Slope Grading
Alternative 2 – Bank and Bed Protection with Valley Slope Grading
Alternative 3 – Pipe Flows
The results of the Class EA evaluation and public consultation led to the identification of Alternative 2 – Bank and Bed Protection with Valley Slope Grading in Reach 1 as the preferred solution.
Scope of Work
The objective of this project is to protect private properties along Clarinda Drive and municipal infrastructure within the valleyland from valley slope instability and accelerated erosion along this tributary of the East Don River.
Through 2023, TRCA intends to:
- Host a second CLC meeting
- File the Class EA Project Plan for a public review period
- Finalize detailed designs for remedial works in Reach 1
- Secure necessary permits and approvals required to proceed to construction
- Proceed with construction in Reach 1
Construction Information
Reach 1 construction is scheduled to start September 2023.
Reach 2 remains on-hold pending results from the City of Toronto’s Newtonbrook & Blue Ridge Creek Geomorphic Systems Master Plan and subject to continued monitoring by TRCA’s Erosion Hazard Monitoring team.
Public Notices
- Notice of Intent (NOI) – TRCA formally initiated the Project in 2020.
- Community Liaison Committee (CLC):
- CLC Meeting #1 – TRCA held a CLC meeting on March 11, 2020 and presented the results of the detailed investigations completed to date. Staff discussed the preliminary alternative erosion control and slope stabilization solutions for the Project area.
- CLC Meeting #2 – TRCA held a second CLC meeting on April 11, 2023. Staff provided a project update, presented on changes to the project scope-of-work since the first CLC meeting, and explained next steps for the project.
- Notice of Filing (NOF) – TRCA issued a NOF on July 6, 2023 to provide details on the filing of the Project Plan for a 30-day public review period.
- Project Plan – TRCA prepared the Class EA Project Plan in accordance with Conservation Ontario’s Class Environmental Assessment for Remedial Flood and Erosion Control Projects (amended 2013). Interested persons were invited to review the Project Plan and provide written comments to the Project Manager. No comments were received during the 30-day public review period.
- Notice of Project Approval (NOA) – TRCA issued a NOA in August 2023 following completion of the 30-day Project Plan public review period.
- Notice of Construction (NOC) – TRCA issued a NOC in August 2023, purpose to provide construction notice and general information to stakeholders and neighbouring residents.
Progress Updates
September 2023
TRCA issued a Notice of Project Approval and Notice of Construction in August 2023. Construction is scheduled to begin September 2023 and tentatively scheduled to be completed by June 2024.
Contact Us
For more information regarding this project, please contact:
Daniel Dyce, Project Manager
Erosion Risk Management
Restoration & Infrastructure
Email: daniel.dyce@trca.ca
Phone: (647) 426-4498