Appalaches-Bas-Saint-Laurent

It is not possible, with current technology, to bury a very high‑voltage transmission line, especially over long distances, mainly because of technical constraints and high costs. As a result, underground technology cannot be applied to a 315‑kV double‑circuit line.

In Québec, our generating stations are very far from major consumption centers. The invention of the very high‑voltage line stems from the need to transport our renewable energy over hundreds of kilometers while maintaining stable voltage levels—a significant challenge.

Undergrounding reduces the transmission capacity of a high‑voltage line: to maintain voltage, a substation would have to be installed every 5 km. This is why only 1% of transmission lines are buried on Québec’s 34,000‑km network. Lines are buried only in very specific contexts—for example, in downtown Montréal, where space is so constrained that it is nearly impossible to find the room needed to install overhead lines.

We held consultations in spring 2025 to present the project and line corridor and gain a better understanding of the territory.

Considering the technical and environmental criteria and the comments, concerns and input we received, our project team is currently developing route variants for the transmission line project that will run through your region.

We will communicate these variants soon.

We plan to share the route with the least impact in fall 2026.

Considering the technical and environmental criteria and the comments, concerns and input we received as part of the consultations held last spring, our project team is currently developing route variants for the transmission line project.

The options will soon be presented for consultation. In 2026, Hydro‑Québec will also conduct environmental inventories on the site to more accurately document the project’s potential impact and determine effective mitigation measures.

The entire process will be set out in an environmental impact statement we will file with the Ministère de l’Environnement, de la Lutte contre les changements climatiques, de la Faune et des Parcs.

Our team will inform the property owners affected by the route variants and invite them to take part in consultation activities to discuss the project and share their thoughts and suggestions on the different options.

Once the variant with the least impact is selected, members of our acquisitions and real estate services team will contact each affected property owner directly to identify the rights to be acquired. Each situation will be assessed to determine the appropriate financial compensation according to the terms of the Hydro‑Québec–UPA Agreement on the Siting of Power Lines on Farms and in Woodlands. Affected property owners will be able to count on support at every stage of the process.

Hydro‑Québec is committed to ensuring its facilities blend into the landscape as seamlessly as possible. When planning new transmission lines, our goal is to minimize their visual impact, preserve the landscape and foster compatibly with other land uses.

Our teams use specialized digital tools throughout the project design phase to limit the visual impacts of any new transmission infrastructure.

This short video (in French) explains our approach.

No. Hydro‑Québec’s transmission system spans more than 34,000 km of high‑voltage lines. Fewer than 1% are underground, and that’s only the case where an overhead line isn’t technically possible or there are unique constraints.

This video on burying transmission lines (in French) illustrates the realities of Hydro‑Québec’s transmission system and the factors that make burial a challenge.

For a 315‑kV line, the right‑of‑way is generally 60 to 70 metres wide. The width varies depending on the area’s specific features and constraints, such as hills, waterways, maple stands, other public infrastructure and farmland.

Our goal is to determine the line route with the least impact and effective mitigation measures.

The preservation of maple stands, as well as other sensitive elements including landscapes, natural environments, populated areas and other agricultural activities, is among the main concerns expressed during the consultations. We consider these elements very carefully when developing line route options.

The owners of all types of property, including maple stands, will be compensated if Hydro‑Québec must acquire a servitude on the land.

Each situation will be assessed to determine the appropriate financial compensation according to the terms of the Hydro‑Québec–UPA Agreement on the Siting of Power Lines on Farms and in Woodlands, which includes specific provisions for land developed for maple operations.

Very early on in the consultation process, several local organizations and stakeholders suggested using public land as much as possible to limit the project’s impact on private property.

That said, to minimize the line’s impact, Hydro‑Québec rigorously assesses each line route variant, whether it crosses public or private land.

The construction of a 315‑kV transmission line isn’t directly linked to the rollout of the three‑phase system, which relies on local 25‑kV distribution infrastructure.

However, adding a transmission line can help increase the system’s capacity in a particular region. In the long term, that could facilitate certain development projects including access to the three‑phase system.

A government assistance program (in French) managed by the Ministère de l’Environnement, de la Lutte contre les changements climatiques, de la Faune et des Parcs supports agricultural operations in rural areas by financing part of the costs to connect to the three‑phase system and advance the energy transition.

Hydro‑Québec aims to reduce electricity use by 21 TWh by 2035, which is equivalent to the consumption of one in four Québec homes. To do so, it will invest $10 billion in measures including:

• No‑cost smart thermostats for homes
• Exemplary building partnerships in the commercial sector
• Tailored support for industrial companies

These initiatives cost three times less than adding new supply sources and help advance Québec’s energy transition.

The Appalaches–Bas‑Saint‑Laurent project component is intended to support wind energy development in the Est du Québec region.

Hydro‑Québec is committed to an unprecedented energy transformation. By 2035, we plan to add 10,000 megawatts (MW) of new wind capacity in Québec. The increase will support the province’s decarbonization, help meet the growing demand for electricity and strengthen Québec’s energy self‑sufficiency.

With that in mind, two development models will coexist: major projects of more than 1,000 MW led by Hydro‑Québec in partnership with municipalities and First Nations communities and standard projects undertaken subsequent to calls for tenders.