Hydro One plays an important role in delivering electricity to your community by supplying power to Toronto Hydro and its customers. We are currently upgrading existing underground transmission cables that provide power to Toronto's downtown core from our Esplanade Transformer Station (TS) to Terualey TS. We anticipate work will be complete in 2026.

Originally built in the 1950s, the underground cables located between our Esplanade Transformer Station (TS) and Terauley TS are reaching their end of life and will be replaced to ensure that we continue to energize the city's most crucial institutions. The map below shows the tunnel route selected for the new cables through the Class Environmental Assessment (EA) process completed for the project in June 2020. The new underground tunnel will run between the stations at a depth of approximately 25 metres below ground in bedrock within existing road allowances.

In addition to the installation of the new tunnel, new tunnel access shafts will be constructed at both Esplanade TS and Terauley TS. During the Class EA process, we communicated that a mid shaft would also be required near the intersection of Sherbourne Street and Shuter Street. We have now completed the design process and determined that the mid shaft is no longer required and will not be built.

Map showing new underground tunnel route:

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


We are pleased to introduce our on-the-ground Construction Ambassador, Jim Goodfellow, who is available to residents during construction. To get in touch, please contact Jim at 647​-446-5720.

Our Construction Ambassador is available to:

  • Complete neighborhood visits as required to meet with residents to discuss questions.
  • Identify necessary accommodations and special requirements, and develop real-time solutions.

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


  • FALL2021
  • Pre-construction engagement

  • By end of2021
  • Start of construction

  • Early
  • Completion of underground tunnel installation

  • By end of2025
  • Completion of construction and new line in service

NOTE: All dates are subject to change

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:

Hydro One Community Relations
Hydro One Networks Inc.

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

Fax: 416-345-6984