Yellow Creek Below Summerhill Gardens Channel Repairs

Toronto and Region Conservation Authority (TRCA) undertook emergency works along a section of Yellow Creek for the protection of essential infrastructure and public safety. To improve channel stability and function, TRCA is planning to undertake channel maintenance and repairs beginning Summer 2024.

Project Location

The project area is located within the Vale of Avoca Ravine (also referred to as the Yellow Creek ravine) and is generally located southeast of Yonge Street and St. Clair Avenue East, in the City of Toronto. The area of concern is a section of Yellow Creek that runs directly below Summerhill Gardens south of David A. Balfour Park.

A red star marks the project area, which is generally located southeast of the intersection of St. Clair Ave East and Yonge Street, in the City of Toronto.
A red star marks the project area, which is generally located southeast of the intersection of St. Clair Ave East and Yonge Street, in the City of Toronto.

Learn More About the Project

 

Project Background

TRCA staff visited Yellow Creek in January 2019 to identify key areas of erosion concern along the watercourse. During this field work, staff found an erosion site at the toe of a steep slope below Summerhill Gardens.

An existing stone and mortar retaining wall next to the slope below Summerhill Gardens was also found to be exposed due to erosion.

An exposed stone and mortar retaining wall located along Yellow Creek below Summerhill Gardens. Source: TRCA, 2019
An exposed stone and mortar retaining wall located along Yellow Creek below Summerhill Gardens. Source: TRCA, 2019

Due to the undermining of this retaining wall, elevated flows during storm events were passing underneath and eroding the toe of slope below Summerhill Gardens.

This erosion was impacting an existing pedestrian trail and created a public health and safety concern within the ravine.

Should no action be taken, continued erosion may have caused future slope failures and threatened essential infrastructure located at the top of slope.

Elevated creek flows through the outflanked channel have resulted in significant erosion at the toe of the slope. Source: TRCA, 2019
Elevated creek flows through the outflanked channel have resulted in significant erosion at the toe of the slope. Source: TRCA, 2019
Toe erosion along the slope next to the outflanked channel has impacted a pedestrian trail and resulted in a public safety concern. Source: TRCA, 2019
Toe erosion along the slope next to the outflanked channel has impacted a pedestrian trail and resulted in a public safety concern. Source: TRCA, 2019

Due to the risks to public health and safety, as well as essential infrastructure, TRCA declared emergency works within Yellow Creek below Summerhill Gardens on July 31, 2019.

Emergency works construction started in Summer 2019 and was completed in Spring 2020. For more information on this previous part of the project please click here.

The goal of that project was to decrease the risk of future slope failures within the project area. TRCA accomplished this through the removal of the exposed stone and mortar retaining wall, realigning the channel away from the western valley slope, and constructing new structures designed to stabilize the channel bed and banks.

Shortly after construction, deficiencies in the new channel configuration were identified on site due to higher than expected levels of flow.

As such, TRCA will be undertaking repairs to address these deficiencies to improve channel function and ensure long-term stability within the channel beginning Summer 2024.

Scope of Work

After post construction monitoring of the original works, it was determined that the higher than expected levels of flow was too great for the original channel repair design.

Thus, with the help of consultants, a more robust design was completed with the additions of armourstone drop structures and energy dissipation pools.

These new structures will help slow down the high rate of flow within the channel, helping to prevent further erosion from occurring.

Throughout 2024, TRCA intends to:

  • Finish construction of the channel repairs and work to restore the natural area
  • Host a community planting event (details to be provided when available)

Construction Information

Emergency works construction started in Summer 2019 and was completed in Spring 2020. For more information on this previous part of the project please click here.

Construction began in August 2024 and is now well underway. Staff have begun preparing the access route and set-up all TPZ/Security fencing, as well as staging and stockpiling areas. Deliveries of construction materials has started and will occur at the intersection of Mt. Pleasant Rd. and Roxbourough Dr. Channel Repair work is set to begin in September.

Public Notices

Declaration of Emergency Works
TRCA declared emergency works on July 31, 2019. An emergency works declaration was distributed to Councillor Mike Layton (Ward 11) as well as to the City of Toronto, the Ministry of the Environment, Conservation and Parks (MECP), and local residents associations.

Notice of Construction
TRCA installed the following information sign at multiple locations throughout the Vale of Avoca Ravine. TRCA also delivered notices to project stakeholders and residences surrounding the project area to notify them of TRCA’s upcoming construction activities.

 


 

Trail Detours/Closures

To ensure public safety and alert trail users, TRCA will close sections of the trail system within the Vale of Avoca Ravine while construction is underway and install trail closure signs where applicable.

Please follow the posted detour routes shown on the map below.

Notice of trail closure sign

Project Updates

2022

  • Retained a design engineer to develop detailed designs
  • Commenced developing detailed designs of the channel repair works

2023

  • Completed detailed designs for the channel repair works
  • Obtained all necessary permits, approvals, and agreements
  • Set-up construction for Spring 2024

Contact Us

For more information regarding this project, please contact Alex Grout, Project Manager:

Alex Grout, Project Manager
Erosion Risk Management
Restoration & Infrastructure
alex.grout@trca.ca
(437)-235-6120