Yellow Creek Below Summerhill Gardens Emergency Works

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 continue work and undertake channel maintenance and repairs.

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. TRCA completed these works in spring 2020. Progress updates showcasing the completed works can be viewed under Project Updates.

Shortly after construction, deficiencies in the new channel configuration were identified on site. As such, TRCA will be undertaking repairs to address these deficiencies to improve channel function and ensure long-term stability within the channel.

Scope of Work

The goal of this 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.

In addition, TRCA restored a section of trail along the west bank that was damaged by channel erosion. A pedestrian bridge that was previously closed by the City of Toronto was also removed to improve public safety. Since this bridge has historical significance, TRCA was able to leave a set of pillars in their existing location and incorporate them into the east bank of the new channel construction.

1900 stereoscopic photo of the historic bridge located within the project site. Source: Lorraine Tinsley, 2019.
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.
A picture postcard dating from the early 1900s depicting the historic Yellow Creek bridge. Source: Lorraine Tinsley, 2019.
Historic east bank bridge pillars.
Preserved historic bridge pillars along east bank of Yellow Creek. Source: TRCA, 2020.

Throughout 2021, TRCA will assess existing channel deficiencies and develop detailed designs that will provide channel improvements and increase long-term channel stability.

Construction Information

Emergency works construction started in summer 2019 and was completed in spring 2020.

A timeline for channel repair works is not yet determined. When repairs are scheduled, this section will be updated with relevant construction information.

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.

Notice of Construction


Trail Closures
To ensure public safety, TRCA had to close sections of the trail system within the Vale of Avoca Ravine while construction was underway. To alert trail users, TRCA installed trail closure signs throughout the ravine.

Notice of trail closure sign

Project Updates

2019 – 2020 Emergency Works

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.
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.
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.
Perimeter fencing installed at the bottom of the steps located at the Shaftesbury Ave trail entrance. 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.
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.
TRCA construction staff can be seen applying a layer of topsoil along the regraded toe of slope below the restored pedestrian trail. Source: TRCA, 2019

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

Update: December 14, 2019

This week construction staff removed the compromised stone and mortar retaining wall and completed constructing the upstream section of the channel.

Construction staff can be seen building the east bank of the channel across from where the stone and mortar retaining wall used to be located. Source: TRCA, 2019.

Update: January 10, 2020

Construction staff have infilled a substantial amount of the the old creek channel to create the top of the east bank.

Looking upstream, the top of the east bank of the newly constructed channel has been created by infilling the old Yellow Creek channel. Source: TRCA, 2020.

Update: January 17, 2020

Construction staff have begun constructing the downstream section of the channel.

A temporary crossing has been installed cross the creek to facilitate construction of the downstream section of the new Yellow Creek Channel. The excavator can be seen sitting atop of this crossing. Source: TRCA, 2020.

Update: January 24, 2020

Construction staff have completed constructing the west bank of the downstream section of the new channel.

Across the creek, the completed west bank of the downstream section of the new Yellow Creek channel can be seen. Source: TRCA, 2020.

Update: February 21, 2020

All Yellow Creek channel works below Summerhill Gardens is complete. Construction staff have commenced undertaking site restoration activities.

This photo, taken at the upstream limit of the work area, showcases the completed reconstruction of the Yellow Creek channel below Summerhill Gardens. Source: TRCA. 2020.

Update: March 6, 2020

Construction staff continue to restore site, including restoring the east side trail located within the Project limits. Restoration work is anticipated to be completed by the end of March 2020 and all trails affected by closures will be re-opened at this time.

The restored east side trail, south of the CP rail bridge. Source: TRCA, 2020.

Update: March 27, 2020

Construction staff have completed restoration of the trail along the east bank. Trail access through the project site is now re-opened for public use.

Restored trail along the east bank of Yellow Creek below the Rosehill Pumping Station. This trail is now open for public use. Source: TRCA, 2020.

Update: April 1, 2020

Pedestrians are currently being detoured around the staging and stockpile area as this area still requires restoration. This area will continue to be cordoned off until substantial restoration is achieved.

Looking south at the northern limit of the staging and stockpile area. Pedestrians are being detoured around to the west side of the ravine at this point. Source: TRCA, 2020.

Update: April 17, 2020

The east side trail located at the south end of the Vale of Avoca ravine has been reopened for public use. The staging and stockpile area adjacent to this path is pending restoration. Public access into this area continues to be restricted.

Looking north, the east side trail passing through the southern reaches of the site has been reopened for public use. The staging and stockpiling area adjacent to the path continues to be fenced off and is pending restoration. Source: TRCA, 2020.

2021

  • TRCA is assessing existing channel deficiencies to inform the development of suitable detailed designs for channel repairs.

Contact Us

For more information regarding this project, please contact Jaya Soora, Project Manager:

Jaya Soora, Project Manager
Erosion Risk Management
Restoration & Infrastructure Division
9755 Canada Company Avenue, Vaughan L4H 0A3
(416) 661-6600 ext. 5533
jaya.soora@trca.ca