Yellow Creek Below Summerhill Gardens Emergency Works

Toronto and Region Conservation Authority (TRCA) is undertaking emergency works along a section of Yellow Creek. The goal of this project is to protect essential infrastructure at the top of slope while addressing erosion concerns that threaten public safety in the Vale of Avoca Ravine.

Project Location

The project area is located within the Vale of Avoca 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.

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

Due to the undermining of this retaining wall, elevated flows during storm events are flowing underneath and towards the toe of the slope. This erosion has impacted an existing pedestrian trail and created a public health and safety concern within the ravine.

Should this erosion not be quickly addressed, continued erosion may cause slope failures and threaten 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
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 risks to public health and safety, as well as essential infrastructure, TRCA declared emergency works for a 90-metre section of Yellow Creek below Summerhill Gardens on July 31, 2019.

Scope of Work

The goal of this project is to remove the exposed stone and mortar retaining wall, and to realign the channel away from the slope. This will help lower the risk of future slope failures in this area.

In addition, TRCA will build erosion control structures within the creek and restore a section of trail along the west bank that was lost due to erosion.

A vegetated island (with significant presence of invasive Japanese knotweed) will be removed to make room for the new channel, and a pedestrian bridge that has been closed by the City of Toronto will be removed to improve public safety.

Because this bridge has historical significance, its pillars will be kept aside and reused in the park, with input from the community and the Ravine Working Group.

1900 stereoscopic photo of the historic bridge located within the project site. Source: Lorraine Tinsley, 2019.
A picture postcard dating from the early 1900s depicting the historic Yellow Creek bridge. Source: Lorraine Tinsley, 2019.

TRCA plans to use existing stone materials as part of the new erosion control structures. This will reduce the amount of new stone material that needs to be purchased for this project.

TRCA will perform restoration work following construction. In addition, the City of Toronto will install tree plantings to offset the trees that were removed as part of the emergency works.

Construction Information

Construction started on August 29, 2019 and should be finished by the winter of 2019-2020.

TRCA has installed perimeter construction fencing to ensure public safety and isolate the work area. The installation of construction fencing has resulted in temporary trail closures, limiting access to a portion of the ravine while work is underway.

During construction, access to the Evergreen Brickworks from the Avoca Ravine will only be possible from the Shaftesbury Avenue or Mathersfield Drive trail entrances. Please expand the interactive map below for further details on trail closures in the Avoca Ravine.

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 has installed the following information sign at multiple locations throughout the Avoca Ravine. In addition, TRCA delivered notice letters to residences near the project area prior to construction.


Trail Closures
To ensure public safety, TRCA has closed sections of the trail system within the Avoca Ravine while construction is underway. To alert trail users, TRCA has installed trail closure signs throughout the Avoca Ravine.

 

Project Updates

Check here for weekly construction updates. Our team greatly appreciates your continued patience while we work on this project.

Update: September 6, 2019

Site perimeter fencing has been installed around the staging and stockpile area and along the trail to isolate the work area along the east side of the ravine. Erosion and sediment control measures have been also been installed throughout the site. The pedestrian trail located along the west bank near the work area will remain open until heavy machinery commence channel work.

Perimeter fencing installed at the entrance of the Yellow Creek Emergency Works site. Source: TRCA, 2019.

Update: September 20, 2019

Mud mats have been installed throughout the project site for the protection of buried municipal infrastructure.

Mud mat installation at the Yellow Creek Emergency Works site. Source: TRCA, 2019.

Update: October 11, 2019

Perimeter fencing has been installed at the bottom of the steps located at the Shaftesbury Ave trail entrance and the northwest limit of the project site to isolate the work area along the west side of the ravine and protect public safety from the hazards of construction activities.

Perimeter fencing installed at the bottom of the steps located at the Shaftesbury Ave trail enttrance. Source: TRCA, 2019.

Update: November 1, 2019

The impacted pedestrian trail located along the west bank has been restored; however, this trail is not yet open to the public due to continuing construction activities.

Restored pedestrian trail located along the west bank of Yellow Creek below Summerhill Gardens. Source: TRCA, 2019.

Update: November 15, 2019

TRCA staff have completed filling and regrading the toe of slope below the restored pedestrian trail to repair a large erosion scar.

TRCA construction staff can be seen applying a layer of topsoil along the regraded toe of slope below the restored pedestrian trail.

Update: November 22, 2019

TRCA staff have substantially completed a segment of the new creek channel, including installation of erosion control measures to provide protection to the banks.

TRCA construction staff can been seen installing an erosion control blanket along the banks of the newly excavated Yellow Creek channel. Source: TRCA, 2019.

Update: November 29, 2019

TRCA staff have substantially completed work along the top of the west bank of the new creek channel.

TRCA construction staff have regraded the top of the west bank and installed an erosion control blanket. Source: TRCA, 2019.

Update: December 6, 2019

TRCA staff are proceeding with preparation activities to remove the undermined stone and mortar retaining wall and complete the upstream section of the new Yellow Creek channel design.

TRCA construction staff can be seen in the distance working with the excavator to prepare the upstream section of Yellow Creek for the dismantling of the stone and mortar retaining wall. Source: TRCA, 2019.

Contact Us

The Project Planning Team is located at TRCA’s Boyd Field Centre in Vaughan:

Restoration & Infrastructure Division, Engineering Projects
9755 Canada Company Ave
Vaughan, Ontario
L4H 0A3

For more information regarding this project, please contact Ashour Rehana, Manager.

Ashour Rehana, Manager
Engineering Projects
Restoration & Infrastructure Division
ashour.rehana@trca.ca
416-661-6600 ext. 5524