East Don River Behind Clarinda Drive Erosion Control and Slope Stabilization Project

Toronto and Region Conservation Authority (TRCA), in partnership with the City of Toronto, has completed channel erosion control and valley slope stabilization works in Reach 1 of Blue Ridge Creek (East Don River tributary), behind Clarinda Drive, in the City of Toronto. The purpose of this Project was to protect private properties and municipal infrastructure from erosion and slope instability hazards, helping to ensure resilient watersheds and contribute to the protection of public greenspace. TRCA 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.

Project Location

The Project site 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. Blue Ridge Creek, 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 for planning and design purposes 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.

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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 and assessments to determine the extent of risk to structures and infrastructure in this area over the long-term from erosion and slope instability hazards. Based on the results of these assessments it was determined that private residential dwellings and municipal sewer infrastructure were at risk should no remedial works be undertaken. To address this risk, TRCA initiated the Project to provide long-term, low maintenance protection to at-risk structures and infrastructure adjacent to and within the project area.

The degraded condition of ravine and tributary banks behind Clarinda Drive in Reach 1. Source: TRCA, 2019.
The degraded condition of the ravine and tributary banks behind Clarinda Drive in Reach 2. Source: TRCA, 2019.

This project was planned and designed in accordance with Conservation Ontario’s Class Environmental Assessment for Remedial Flood and Erosion Control Projects (amended 2013) (Class EA), the approved planning approach for this type of work. The following diagram provides an overview of the Class EA process. The Class EA led to the identification of Alternative 2 – Bank and Bed Protection with Valley Slope Grading in Reach 1 as the preferred solution.

Public Notices

Scope of Work

  • Construction Start: August 2023
  • Construction Completion: June 2024

The objective of Reach 1 of this Project was to protect private properties along Clarinda Drive and municipal infrastructure within the valleyland from valley slope instability and accelerated erosion hazards.

Scope of work included required tree and vegetation removals, construction of channel bank and bed erosion controls and valley slope regrading for approximately 205 m of tributary, and comprehensive restoration planting including native tree and shrub planting.

Before and after construction (TRCA, 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