The provincial energy planning directorates, regional utility networks, and municipal infrastructure panels across eastern southern Ontario have advanced a major grid modernization project. Tracked under provincial regulatory registries on Thursday, July 2, 2026, corporate transmission planners finalized the formal regulatory submission for ‘The needs of the future’: Hydro One proceeds with Durham Kawartha power line. Seeking to dramatically increase bulk power transfer capacity and fortify regional reliability following recent severe weather events and escalating clean energy demands, the utility giant has escalated the project to the Ontario Energy Board (OEB) for absolute route approval.
The massive capital project will establish a heavy-duty high-voltage connection spanning multiple county lines, providing a critical new layer of grid stability between Durham’s industrial hubs and the Kawartha lakeshore region.
The Transmission Line Engineering and Route Specifications
The formal “Leave-to-Construct” filing details a high-capacity linear energy corridor designed to meet projected clean-energy load growths over the coming decades.
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The Transmission Capacity: The newly designed utility artery will operate as a high-volume 230-kilovolt (kV), double-circuit transmission line.
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The Physical Footprint: The linear corridor will span precisely 55 kilometres across rural and semi-urban geography.
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The Station Termini: The line will run directly from the massive Clarington Transformer Station (located in the Municipality of Clarington) and cut northeast to terminate at the Dobbin Transformer Station in the City of Peterborough.
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The Projected Timeline: Pending standard regulatory approvals and environmental impact assessments from the OEB, heavy ground crews are projected to initiate corridor clearing and tower construction by early 2027.
Analyzing the Durham-Kawartha Bulk Grid Expansion Framework
The multi-year capital investment aims to drastically reduce regional vulnerability to the types of systemic supply disruptions that have caused widespread power outages during recent summer heatwaves.
| Infrastructure Node / Point | System Engineering Designation | Primary Grid Connectivity Purpose | Next Scheduled Regulatory Milestone |
| Clarington Transformer Station | Southern Regional Source Hub | Feeds high-voltage bulk power from major nuclear & provincial generation pools | Final OEB evidentiary document reviews |
| Dobbin Transformer Station | Northern Regional Terminus | Reinforces localized distribution across Peterborough & Kawartha grids | Environmental field asset clearances |
| 55-Km Interconnecting Corridor | 230-kV Double-Circuit Line | Creates a redundant high-capacity pathway to prevent localized grid drops | Targeted construction kickoff in 2027 |
The project steps out of a multi-phase public consultation process that launched across Clarington and Peterborough last year. Landowners along the proposed right-of-way will be receiving targeted direct mailers over the summer mapping out property border updates, construction safety margins, and land use agreements as Hydro One prepares its final engineering drafts.
The Ontario Energy Board manages the central registry for all formal utility construction review hearings.
Clarington property owners, local energy consumers, and residents looking to look over the complete OEB Leave-to-Construct files, view high-resolution route alignment maps, or register for upcoming public input sessions can find the digital documentation online at oeb.ca or monitor project updates directly via hydroone.com/durham-kawartha.
