West Don River near Langstaff Park Sanitary Protection Project

Toronto and Region Conservation Authority (TRCA) is preparing to implement regional infrastructure protection works along the West Don River, in the City of Vaughan, in order to provide long-term protection to at-risk sanitary sewer infrastructure.

Project Location

The West Don River near Langstaff Park Sanitary Protection Project (P-128) is located along a section of the West Don River, within the Don River watershed. The closest major intersection to the project area is Langstaff Road and Keele Street, in the City of Vaughan.

Figure 1.  Map highlighting project area in relation to the closest main intersection of Langstaff Road and Keele Street. Source: TRCA, 2019.

Learn More About the Project

Project Background

In 2011, TRCA developed the Infrastructure Hazard Monitoring Program (IHMP) in association with the Regional Municipality of York.

The purpose of the IHMP is to ensure timely identification of risk to infrastructure due to watercourse activity (i.e. channel migration, widening, etc.) and efficient prioritization and mitigation of such risks in collaboration with stakeholders.

The IHMP broadly divides watercourse erosion risks into two types of sites: intersection sites to assess the risk of bed erosion where the sewer crosses a watercourse, and proximity sites to assess the risk of bank erosion and lateral channel adjustments in close vicinity to the infrastructure. Intersection sites are categorized using an “I-” identifier, while proximity sites are categorized using a “P-” identifier.

In regards to this project, Site P-128 consists of a 750 mm gravity sanitary main and maintenance hole that are at risk of being exposed along the river bank due to bank erosion and channel migration.

In 2011, Site P-128 was classified as a high priority due to the substantial decrease in the distance between the top of bank and the sanitary main over time. In addition, large storm events in summer 2017 and 2018 accelerated erosion at the site which led to significant bank recession.

Field observations have confirmed the presence of undercut banks with tension cracking and extensive scouring adjacent to to the sanitary main. Several failed trees and debris jams are also present in the area.

Figure 2. Bank scouring, failed trees, and debris jam at Site P-128. Source: TRCA, 2018. 
Figure 3. TRCA staff standing on the maintenance hole at Site P-128 indicating the location of infrastructure in relation to the scoured bank. Source: TRCA, 2019. 

The proposed remedial works at Site P-128 includes the construction of a buried rock trench in front of the sanitary main, as well as a vegetated rock revetment, brush mattressing and woody debris habitat treatment along the left bank of the watercourse.

The buried rock trench will extend approximately 5 metres upstream and downstream of the vegetated revetment treatment. This proposed buried stone trench treatment will allow for natural watercourse movement and migration, while at the same time, provide future sanitary infrastructure protection, if necessary.

Three cedar root wad treatments will also be installed within the bank revetment in order to enhance aquatic habitat.

Scope of Work

  • Geomorphic study, Concept Evaluation Report and Environmental Impact Statement (completed in 2018)
  • Detailed design development (completed in summer 2019)
  • Obtain all necessary permits and approvals to proceed with construction (2019)
  • Implementation of remedial works (tentatively November 2019 to early 2020)
  • Site preparation including tree removals, site isolation and erosion and sediment control set up (tentatively November 2019)
  • Installation of vegetated rock revetment and buried rock trench (tentatively November 2019 to early 2020)
  • Site restoration, including native tree and shrub plantings and demobilization (tentatively spring 2020)

Construction Information

Construction is tentatively scheduled to begin in November 2019. Please note that the project area, including a portion of the Langstaff Park recreational trail and parking lot, will be closed for the duration of construction. For your safety, please respect all posted construction signs and stay clear of work areas and equipment. Your patience and cooperation is appreciated.

Public Consultation

The project has been developed under a Schedule A+ Municipal Class Environmental Assessment.

Project information signs, which will include details regarding trail closures, will be installed at the adjacent park entrances and/or access points.

Project Updates

Please check back here for further updates closer to construction.

Contact Us

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

Restoration and Infrastructure Division, Erosion Risk Management
9755 Canada Company Avenue
Vaughan, Ontario
L4H 0A3

For more information regarding this project, please use the contact details outlined below:
Phil Wolfraim, Project Manager 
Erosion Risk Management
Engineering Projects, Restoration & Infrastructure Division
phil.wolfraim@trca.ca
416.661.6600