The project

Why is this project necessary?

This project is necessary to meet the growing demand for electricity, which increased by 20% between 2004 and 2012. The annual growth of electricity demand in the region is 2.8%, twice the Québec average.

Many of the substations and supply lines that are part of the Laurentides’ regional transmission system have reached their capacity.

Various scenarios for electricity supply in the MRCs of Pays-d’en-Haut and Laurentides [pdf] were studied to meet the growing demand for electricity in the region. After analyzing these different options, Hydro-Québec is proposing to build a 120-kV line, approximately 40-km long, in these MRCs.

This new 120-kV line will help support residential, commercial, economic and tourism development in the region, as well as meet electricity needs for the next 20 years. More specifically, the new line will transfer the electricity supply for Saint-Sauveur substation and Doc-Grignon substation (in Sainte-Adèle) to Grand-Brûlé source substation in Mont-Tremblant.

Technical characteristic

What are the technical characteristics of the line Hydro-Québec is proposing to build?

About 40 km
Towers and conductors
To meet the significant increase in electricity demand in the region while keeping impacts to a minimum, Hydro-Québec plans to build a 120-kV double-circuit line, with twelve conductors (wires) instead of six (equivalent to two 120-kV lines). Since there are twice as many conductors, stronger towers will be required. These support structures do not alter the line’s voltage.
This project is for a 120-kV line. The transmission system in the Laurentides is operated at 120 kV.
The width of the right-of-way will vary based on the type of tower and the maintenance methods required.
735-kV lines south of the Grand-Brûlé substation.

Has Hydro-Québec studied other scenarios to meet the growing demand for electricity in the region?

Various scenarios for electricity supply in the MRCs of Pays-d’en-Haut and Laurentides MRCs were studied to meet the growing demand for electricity. The other scenarios have more significant environmental and human impacts and higher costs.

After analyzing the different scenarios, Hydro-Québec is proposing to build a 120-kV line, approximately 40-km long, in these MRCs.

Why can’t Hydro-Québec bury this transmission line underground like it would in downtown Montréal or Québec?

Burying a transmission line like this one, at this location, would cost more than four times the price of the solution proposed. The cost of burying a line can even be 6 to 10 times the price of an overhead line in cases where, for example, there is rock close to ground level.

Hydro-Québec TransÉnergie, the division in charge of electricity transmission between powerhouses and the distribution system, is responsible for ensuring a reliable and high-quality transmission service and for increasing the capacity of the system to meet customers’ needs, while optimizing costs.

As for burying high-voltage lines, there are many technical constraints involved:

  • An overhead-underground junction substation of about 30 m x 30 m is required at each extremity of the underground portion of the line.
  • Joint bays are required at every 800 m.
  • Transit capacity is lower underground. For a capacity equivalent to the proposed line, two parallel cables would be required, which would lead to a significant increase in costs.
  • The service life of an underground cable is 40 years, whereas overhead lines last 70 years.
  • Locating and fixing failures in underground lines takes much longer than in overhead lines.

Burying a high-voltage line also involves significant environmental impacts, especially in certain sensitive areas (wetlands, waterways, etc.).

Can the visual impact of a high-voltage line be reduced?


The chosen environmental assessment method used by Hydro-Québec for power line projects includes a detailed landscape study. The goal of this study is to characterize the various types of landscapes in the study area in order to determine which are the most sensitive to a line crossing.

Various siting criteria can then be used to integrate the line into the landscape as much as possible:

  • Look for backgrounds that allow the line to be visually absorbed.
  • Take advantage of any existing visual screens.
  • Make the most of the topography, etc.

Carefully choosing tower placement and tower type based on the environment crossed can also improve a line’s visual integration into a given area.

Government authorizations

Is this project subject to BAPE hearings?


It is the voltage of the line that determines the applicable environmental review process. In accordance with current laws and regulations, the present project is not subject to an environmental review process.

Projects to build a 120-kV line more than 2 km long that could potentially impact the environment require a certificate of authorization under section 22 of the Environment Quality Act. In order to obtain this certificate, an environmental impact statement must be filed with the ministère du Développement durable, de l’Environnement, et de la Lutte contre les changements climatiques (MDDELCC).

The line proposed has all the characteristics of 120-kV lines, including in terms of the rights-of-way and clearing required. The towers needed to support a 120-kV line are shorter and narrower than the towers for 315-kV lines. The right-of-way for a 120-kV line is also narrower than that for a 315-kV line.

Public consultation

Did Hydro-Québec consult with the public for the project?

To date, more than 95 meetings have been held with elected officials, managers, representatives of various local organizations, landowners and citizens affected by the project to gather their concerns and respond to their information needs.

For example, four open house sessions were organized in March 2013, to which several hundred landowners, vacationers and residents from the affected areas were invited, and during which Hydro-Québec presented the possible line routes and held discussions with the various stakeholders.

In addition, four public information meetings took place in November and December 2014, to present the improvements made to the initial project, the optimized line route and the new technical characteristics to the general population.

Hydro-Québec used various means to inform and consult the people affected by the project. For example:

  • We organized meetings with elected officials and municipal managers representing residents, as well as with regional and local organizations.
  • We held public consultation activities, such as open house sessions.
  • We distributed information bulletins and press releases at the key stages of the project.
  • The public can obtain more information about the project by calling the Info-project line (toll-free phone line).

How does Hydro-Québec make sure that the expectations and concerns of the public and the organizations affected by the project are taken into account?

Hydro-Québec wishes to carry out its projects in partnership with the communities concerned.

Therefore, the company makes sure stakeholder groups are involved from project announcement to the commissioning of equipment in order to collaborate on developing the best possible power transmission project.

Hydro-Québec implements a public participation program designed to provide an understanding of the project, respond to stakeholders’ information needs and gather community concerns regarding the project. The company communicates with representatives of various levels of government and the communities, affected property owners, residents, community organizations, contractors, suppliers and local media.

This public participation process helps ensure that projects blend in with their environment and enhances their acceptance by the community (see the document Public participation regarding a power transmission project). The consultations with stakeholders are helpful in determining the line route that will have the least social, environmental, technological and economic impact. These discussions also mean that project development can respond better to host community needs and expectations.

120-kV line leaving Saint-Sauveur substation.