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Power Downtown Toronto

Energizing life for communities

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.

Expected Completion Date : 2026

Community benefits
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Project overview

As part of our commitment to energizing life, we are upgrading underground cables that energize Toronto's downtown core. The underground cables between Esplanade Transformer Station (TS) and Terualey TS have served the area since the 1950s and need to be replaced to ensure we continue to energize critical institutions in the City. The new underground tunnel will have entry points within each TS and is being constructed at a depth of approximately 25 metres and within existing road allowances. We anticipate the project will be complete and in-service in 2026.

We’re here to help you

If you have any questions during construction, please contact our Construction Ambassador, Rick Parnell at 647-969-5744.

For any other questions and to join the project contact list, please contact Hydro One Community Relations at:

1-877-345-6799

Project map

The underground route was selected as part of the Class EA process, which was completed in 2020. A mid-shaft near Shuter Street and Sherbourne Street was not required.

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Project map

Benefits to the city

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Energizing life

Hydro One is proud to energize life for the City of Toronto by delivering power to Toronto Hydro through our transmission network.

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Safe and reliable

The infrastructure renewal project ensures clean and reliable energy to some of Toronto's most critical institutions, including Hospital Row, City Hall and the Financial District.

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Clean energy

The project will provide a reliable supply of clean electricity, which means the City and its communities and businesses can continue to grow.

Planning process

The replacement of underground transmission cables is subject to the Class Environmental Assessment (Class EA) for Minor Transmission Facilities (Hydro One, 2016), in accordance with the Ontario Environmental Assessment Act. The Class EA is a streamlined planning process that ensures that minor transmission projects that have a predictable range of effects have feasible environmental mitigation and/or protection measures in place.

The Class EA process for this project was completed in June 2020. In addition, Leave to Construct approval from the Ontario Energy Board was approved in 2021. All necessary permits and approvals will also be in place.

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Anticipated project schedule

Summer 2018
Notice of Commencement
Winter 2019
Virtual Community Open House #1; Introduction of Project
Winter 2020
Community Open House #2; Update on Project
Spring 2020
Draft Environmental Study Report (ESR)
February 2021
Completion of detailed design and other permits and approvals, including Section 92 approval from the Ontario Energy Board
Summer 2022
Community Events - Construction activities at Esplanade TS
Fall 2022
Community Open House - Construction activities at Terauley TS
2026
Project complete and in-service
*Dates are subject to change.
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Frequently asked questions

What is the Power Downtown Toronto project?

Hydro One must replace critical underground transmission cables that serve Toronto’s downtown core and are approaching their end of life. These cables currently run between Esplanade Transformer Station (TS) and Terauley TS. Through a Class Environmental Assessment (EA), we evaluated several route alternatives and two different construction methodologies to install the new cables. A new underground tunnel was selected to house the new cables.

What is the need for this project?

The cables that run between Terauley Transformer Station (TS) and Esplanade TS have served Toronto’s downtown core since the 1950s, and are approaching their end of life. Replacing these critical transmission cables will ensure that we are able to continue to provide reliable power to institutions in the area such as TTC, hospitals, businesses, residential buildings, and universities and colleges.

When will construction start and how long will it take?

Construction consists of installing a new tunnel 25 metres below ground between Esplanade TS and Terauley TS, as well as the installation of access shafts within both stations. Construction began in 2022 on the access shafts and tunnel installation will begin in early 2023. The overall project will be complete in 2026.

What will the route for the new cables be?

The proposed underground tunnel will run between Esplanade Transformer Station (TS) and Terauley TS at a depth of approximately 25 metres below ground within road allowance. Please click here to view the map.

What will Hydro One do to mitigate impacts from construction?

As we will be constructing an underground tunnel for the new cables, we anticipate that surface impacts will be mainly limited to shaft locations at Esplanade TS and Terauley TS. Shafts are required to enter and exit the shaft as follows:

  • Location A - Entry shaft to be located on Hydro One’s property at Esplanade TS
  • Location B - Exit shaft to be located inside Terauley TS

Click here to join our contact list and to be notified of construction updates and upcoming engagement opportunities.

How will Hydro One communicate updates to the community?

During construction, Hydro One will focus on sharing updates through our project contact list and this web page. To ask a question or join our project mailing list, please email us or call us at 416.345.6799

Public consultation documents

A Class Environmental Assessment (EA) was completed in 2020 and Leave to Construct approval from the Ontario Energy Board was received in 2021. Construction began in 2022 and Hydro One will continue to share information and updates as the project progresses. Information about past engagement opportunities including Class EA materials and construction updates can be viewed by clicking the drop-down menu below.

Open house resources

November 2022

Download the information panels - November 8, 2022 Download community open house invitation - November 8, 2022

February 2020

Download the open house #2 information panels - February 2020 Download the open house #2 invitation - February 2020 Download the information panels - February 26 and 28, 2020

February 2019

Download the open house invitation - February 2019

Notice of commencement

June 2018

Download the Notice of Commencement - June 2018

Project updates

April 2024

View the construction update that was send by email in April 2024 Community update sent to properties near Terauley TS - April 2024

June 2023

Construction update - June 2023

January 2023

Construction update - January 2023

May 2022

Watch our virtual presentation - May 2022

April 2020

Notice of completion of Draft Environmental Study Report - April 2020

June 2018

Download the Notice of Commencement - June 2018

November 2018

Update on the progress of the Class EA - November 2018

Environmental Study Report and appendices

Final Environmental Study Report Appendix A – Past study area maps Appendix B – Duty to consult Appendix C – Consultation Appendix D – Environmental inventory figures and tables Appendix E – Supporting environmental reports and information Appendix F – Alternative routes evaluation table Appendix G – City of Toronto inview database Appendix H – Statement of completion

Land acknowledgement

Hydro One acknowledges that we are on the Traditional lands of the Mississauga, the Anishinabek, the Haudenosaunee and Huron-Wendat Nations.​ Hydro One also acknowledges that these lands are covered by Treaty 13 signed with the Mississauga of the Credit First Nation and the Williams Treaties.​

To provide comments or to be added to the project contact list, please connect with us

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