OUTAOUAIS Coulonge substation and supply line

The 120/25‑kV substation and 120‑kV supply line under study involve the MRC of Pontiac.

Aerial photo of the Marchand Covered Bridge crossing the Coulonge River

Open house

In May 2026, we went to Pontiac to talk to the public about the proposed Coulonge substation and its supply line. This project aims to upgrade the power system and support regional development.

Some 60 people came out to meet with us. We would like to thank you for your participation and your interest.

We hope to see you again in fall 2026 for the next activity.

Project description

Why?

  • Upgrade the power transmission system in the regional county municipality (MRC) of Pontiac.
  • Improve the grid’s reliability and resilience as weather events become increasingly intense.
  • Meet the growing demand for electricity in the Pontiac region.
  • Contribute to economic development and the energy transition.

How?

  • Build a 120/25-kV substation in the Fort-Coulonge and Mansfield-et-Pontefract sector.
  • Build a 120-kV supply line over 30 km between Cadieux substation and the upcoming Coulonge substation.
  • Rebuild Cadieux substation in the municipality of Bryson.

Project schedule

  1. 2025-2026

    Draft design phase: technical studies, environmental assessment and public consultation

  2. 2026-2028

    Government approvals

  3. 2028-2030

    Work

  4. 2030-2031

    Commissioning

Study area

Hydro‑Québec as established a study area to determine the substation location and line route with the least impact. The study area includes all the biophysical and human elements that are likely to be affected by the project. Extending some 187 km2, the study area is situated entirely in the MRC of Pontiac.

Download the map [PDF 6.9 MB]

RELATED WORK
Rebuilding Cadieux substation

Where?

On the site of the existing Cadieux substation
(150, chemin de Calumet, Bryson)

Why?

  • Upgrade the substation built in the 1960s
  • Increase the substation’s capacity
  • Improve equipment reliability
  • Ensure the electricity supply to L’Isle-aux-Allumettes

When?

  • Planned for 2029–2030
Photo of the Cadieux substation in winter

Substations: Essential hubs

Naviguez entre les onglets avec les flèches droite et gauche, puis accédez au contenu avec la touche tabulation

Explore an electrical substation. See the vital role it plays in transmitting and distributing power from the generating station to the home.

Running time: 5 minutes [in French only]

Documents

Contact

We want to keep the lines of communication open. Send us your questions and comments about the project.

Info-project line: 1 866 388‑1978

Johanne Savard

Advisor – Communications and Communities

Simon Desjardins

Advisor – Community Relations

affairesregionales@hydroquebec.com

Emmanuel Bertrand‑Gauvin

Advisor – First Nations and Inuit Relations

bertrand-gauvin.emmanuel@hydroquebec.com

Related content