The final Environmental Study Report is now available to download.


Hydro One plans to replace critical underground transmission lines that serve Toronto’s downtown core.

The cables being replaced were installed in the 1950s and are approaching their end of life. This work will help continue to provide power to our city’s most crucial institutions, including major banks, businesses, hospitals and universities.

Since the Class Environmental Assessment was initiated for this project in May 2018, we have been reviewing environmental and technical data, and collecting feedback and input on alternative routes and construction methods. Based on this analysis and information, we have now selected our preferred route, Tunnel Route 1, shown on the map below.


Map of the Power Downtown Toronto Project preferred route
Click to enlarge (.PDF)

Pending project approvals and permits, construction is planned to begin in Spring 2021 and be completed in December 2024. View the latest updates using our online engagement forum.

image of Transmission towers in a corridor strung with high-voltage powerlines

Timeline: Public and Stakeholder Consultation for Class Environmental Assessment

  • MAY2018
  • Initiation of Class Environmental Assessment

    Initiation of online engagement

  • FEB2019
  • Open House #1

  • FEB
  • Open House #2

  • MAY/
  • Release of draft Environmental Study Report and comment

NOTE: All dates are anticipated and could change based on project feedback.
Previous dates have changed to accommodate a refined project study area and route options


Ongoing consultation opportunities including workshops, online engagement, pop-up events and individual meetings with First Nations and Métis communities, government agencies, interest groups, Business Improvement Areas (BIAs) and property owners will continue throughout this timeframe.

Project Approvals

Learn more about the Class EA being conducted to support the Power Downtown Toronto project.

Project Approvals
Public Consultation

Learn more about the Public Consultation initiatives we'll be conducting to support this project.

Public Consultation

View maps related to this project.

Frequently Asked Questions

Get answers to questions you may have about this project.

Frequently Asked Questions

Contact Us

For more information or to be added to the project contact list, please contact:

Dana Gardner
Community Relations
Hydro One Networks Inc.

Tel: 416-345-6799 or 1-877-345-6799

Fax: 416-345-6984