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Greater Toronto Area East Regional Planning

Strong community growth is being seen in many areas across the Greater Toronto Area East (GTA East) Region. Plans to accommodate urban intensification and the new "Seaton" community north of Pickering require integrated regional solutions to ensure that the electricity system can continue to supply the demand over the long term.

In order to understand and meet specific local electricity needs, the region was divided further into two sub-regions – Pickering-Ajax-Whitby, and Oshawa-Clarington.

Current status: An Integrated Regional Resource Plan (IRRP) has been released for the Pickering-Ajax-Whitby sub-region.

The Needs Screening determined that no further regional coordination is required for the Oshawa-Clarington sub-region at this time.


The GTA East region extends from Lake Ontario northward to the southern parts of Scugog and Uxbridge, and includes the municipalities of Pickering, Ajax, Whitby, Oshawa and parts of Clarington within Durham Region. The area is supplied by several transformer stations fed by the 230 kV transmission system in the area.

The local distribution companies (LDCs) providing service to this area include: Hydro One Distribution, Oshawa PUC Networks,Veridian Connections Inc., and Whitby Hydro Electric Corporation.

GTA East map

Map of GTA East 


Regional Planning Initiative Underway in this Region

Pickering-Ajax-Whitby sub-region

The Pickering-Ajax-Whitby area includes most of the City of Pickering, Town of Ajax, part of the Town of Whitby, and part of the Townships of Uxbridge and Scugog. Over the past 10 years, new residential development and associated commercial and small industrial customers have pushed the average electrical demand growth rate to approximately 2% per year. In addition, the area hosts many large industrial customers, including steel and auto manufacturers that connect directly to the transmission system.

The IESO released a Scoping Report in September 2014. It concluded that an Integrated Regional Resource Plan (IRRP) should be undertaken to further assess the capacity and restoration needs in the Pickering-Ajax-Whitby sub-region of GTA East. A Working Group, consisting of representatives from Hydro One Distribution, Veridian Connections Inc., Whitby Hydro Electric Corporation, Hydro One Networks Inc., and the IESO, determined that conservation, generation, transmission and distribution, and innovative resources are potential options to be considered to meet local needs. An IRRP was selected as the preferred planning approach in this sub-region.

Current status: An Integrated Regional Resource Plan (IRRP) has been released for the Pickering-Ajax-Whitby sub-region.


How to get involved

A Local Advisory Committee (LAC) has been established for the broader GTA East region. The role of the LAC is to provide advice and recommendations on the development of the Pickering-Ajax-Whitby Integrated Regional Resource Plan, an avenue for broader energy dialogue, and also act as bridge between the five-year planning cycles. Thank you to all who submitted a nomination.

To find out when the LAC is meeting and to participate, see GTA East Region engagement initiative.

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Area overview

The peak demand in this area from residential, commercial, and small industrial customers is currently around 430 MW, and is served by two step-down transformer stations, Cherrywood TS, and Whitby TS. In addition, the region hosts a number of large industrial customers that connect to the grid using their own transmission system assets.


Oshawa-Clarington

The Needs Screening determined that no further regional coordination is required for this sub-region at this time. The Needs Assessment report is available on Hydro One's regional planning page for the GTA East region.