Item - 2026.IE30.7

The Infrastructure and Environment Committee:

1. Forwarded the item to City Council without recommendation.

This report presents the main concerns and considerations, as understood by City staff, raised by the Province of Ontario and energy utilities regarding development in proximity to the Hearn Switching Station (Hearn Switching Station) as requested at the March 25, 26 meeting of Toronto City Council, Item TE29.14 – 402 and 440 Unwin Avenue – Official Plan Amendment – Appeal Report.

In TE29.14, City Council provided direction on an Official Plan Amendment appeal by Studios of America Corporation for the lands municipally known as 402 and 440 Unwin Avenue in the Port Lands. The Official Plan Amendment application proposes, among other matters, to introduce residential uses on the site. Residential uses are not permitted anywhere south of the Ship Channel; these lands are identified for port industrial, energy and city-serving uses, destination/catalytic uses, and parks and open space.

This report focuses on "development in proximity to the Hearn Switching Station" which is located adjacent to the aforementioned lands owned by Studios of America Corporation and whose future industrial-based uses are of the City's interest with respect to future energy infrastructure development.

For the purposes of this report, "development in proximity to the Hearn Switching Station" is defined as:

- the area that is currently occupied by the Hearn Switching Station;

- the area that is occupied by the Portlands Energy Centre; and

- any land in the Port Lands that is implicated in the proposed route development of the underwater high voltage direct current transmission connection, called the Toronto Third Line¹.

A review of publicly available documents was undertaken by City staff.

In summary, the concerns and considerations raised, as understood by City staff, by the Province of Ontario and by energy utilities focus on the Hearn Switching Station's role as a critical connection point for delivery of electricity from the point of generation to Toronto's local distribution network. It is City staff's understanding that there are concerns with the importance of the long-term operability of the Hearn Switching Station.

At a high level, the concerns and considerations of each party, as understood by the City, are generally summarized below:

1. Hydro One Networks, operator of the Hearn Switching Station and the province's largest transmitter of electricity, has identified that as a critical hub providing a connection to the Portlands Energy Centre, the Hearn Switching Station contains critical 115 kiloVolt (kV) underground transmission assets that will require attention to above and below ground operation integrity, and specifically, must address access and easement protection, safety considerations, landscaping requirements, loading area and vehicles access, underground infrastructure protection, and development requirements adjacent to the Hearn Switching Station. (See Attachment 1).

2. Atura Power, owner and operator of the Portlands Energy Centre, a gas-fired electricity generating station located directly east of the Hearn Switching Station and which is one source of electricity supply through the Hearn Switching Station, has expressed the importance of ongoing and uninterrupted operation of Portlands Energy Centre to deliver power to Toronto. They highlight that the ability to retain ongoing industrial operations in proximity to the Hearn Generating Station (HGC), which is adjacent to the Hearn Switching Station, must consider compatibility with air emissions as well as other impacts to ensure Portlands Energy Centre's long-term viability. (See Attachment 2).

3. The Independent Electricity System Operator, the Crown corporation responsible for managing Ontario's power system has announced the proposal to construct the Toronto Third Line (TTL) which is a proposed 65 kilometres underwater high-voltage direct current (high voltage direct current ) transmission line connecting the Bowmanville Switching Station in Clarington to the Hearn Switching Station in downtown Toronto. The line is planned to deliver approximately 900 MegaWatts of electricity, equivalent to powering an estimated 900,000 homes, and would include development of a sizeable converter station near the Hearn Switching Station, which is intended to serve as the primary connection point into Toronto’s transmission system. The Independent Electricity System Operator has stated the importance of protecting land for future transmission so as to maintain flexibility to accommodate future growth and mitigate the risk of development that is incompatible with future transmission needs.

¹ https://www.ieso.ca/Sector-Participants/Engagement-Initiatives/Engagements/Toronto-Third-Line