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Early Works

The Ontario Line - Early Works: Lower Don Bridge and Don Yard


In accordance with Ontario Regulation 341/20: Ontario Line Project (O. Reg 341/20), under the Environmental Assessment Act, early works are any components of the Ontario Line Project that Metrolinx proposes to proceed with before the completion of the Ontario Line assessment process, such as station construction, rail corridor expansion, utility relocation or bridge replacement or expansion.

The Lower Don Bridge and Don Yard early works will include:

  • building a new bridge north of the existing rail bridge over the Lower Don River that will carry the Ontario Line tracks;
  • shifting GO tracks in the Don Yard and nearby rail corridor to accommodate Ontario Line infrastructure;
  • modifying the existing rail bridge to accommodate GO track shifts and Ontario Line infrastructure; and,
  • relocating and protecting utilities and signal infrastructure in the area.

Proceeding with Lower Don Bridge and Don Yard early works before completion of the Ontario Line assessment process is beneficial for project planning, design and timely implementation of both Ontario Line and GO Expansion.

View of the north side of the existing rail bridge

View of the north side of the existing rail bridge.
Source: Metrolinx, 2020.

These early works will set the groundwork for other major construction on the Ontario Line Project, reducing risk of construction delays to the main P3 contracts by completing the joint corridor work in advance of the main contracts.

The Lower Don Bridge and Don Yard Early Works Report outlines the purpose of early works, a description of local environmental conditions, potential impacts, proposed mitigation measures and a record of consultation.

The Lower Don Bridge and Don Yard Early Works Report is available for review.

View the Full Early Works Report

Environmental impacts of the Lower Don Bridge and Don Yard early works are being assessed in accordance with Ontario Regulation 341/20: Ontario Line Project (O. Reg. 341/20), under the Environmental Assessment Act. The early works assessment process includes the following:

  • Reviewing and examining early works components and activities
  • Understanding local environmental conditions through desktop reviews and field studies
  • Assessing and evaluating potential impacts that early works components and activities may have on the environment
  • Proposing mitigation measures to avoid or reduce impacts and monitoring activities to verify effectiveness of mitigation measures
  • Determining any municipal, provincial, federal or other permits and approvals that may be required as planning progresses

The Draft Lower Don Bridge and Don Yard Early Works Report provides the following:

  • A description of the early works, including a description of the alternatives considered
  • A map showing the site of the early works
  • The rationale for proceeding with the early works and a summary of background information
  • A description of the local environmental conditions at the site of the early works
  • A description of all studies undertaken
  • Metrolinx’s assessment and evaluation of the impacts that the preferred method of carrying out the early works and other methods might have on the environment, and Metrolinx’s criteria for assessment and evaluation of those impacts
  • A description of any measures proposed by Metrolinx for mitigating any negative impacts that the preferred method of carrying out the early works might have on the environment
  • A description of the means Metrolinx proposes to use to monitor or verify the effectiveness of mitigation measures proposed
  • A description of any municipal, provincial, federal or other approvals or permits that may be required for the early works
  • A consultation record

The Lower Don Bridge and Don Yard early works include building a new bridge north of the existing rail bridge over the Lower Don River that will carry the Ontario Line tracks; shifting GO tracks in the Don Yard and nearby rail corridor west of the bridge to accommodate the construction of the Ontario Line infrastructure; modifying the existing rail bridge to accommodate future GO  track shifts and Ontario Line infrastructure; and relocating and protecting utilities and signal infrastructure in the area.

The Project Footprint includes permanent infrastructure to be built as part of early works as well as lands that may be needed to support construction staging/laydown and access on a temporary basis. The extent of lands anticipated to be temporarily impacted by construction will continue to be refined and reduced to the extent feasible as project planning progresses.

Map

 

View of the north side of the existing rail bridge

Conceptual rendering of Lower Don Bridge for illustrative purposes only.

Source: Metrolinx, 2021.