The project will deliver 1,250 megawatts of Quebec hydroelectricity to New York City starting in 2025.
It's a 25-year contract for Hydro-Quebec, the largest export contract for the province-owned company.
The Crown corporation has not disclosed potential revenues from the project, but Premier François Legault mentioned on social media last September that a deal in principle worth more than $20 billion over 25 years was in the works.
The route includes a 56.1-kilometre underground and a 1.6-kilometre underwater section.
Eight municipalities in the Montérégie region will be affected: La Prairie, Saint-Philippe, Saint-Jacques-le-Mineur, Saint-Édouard, Saint-Patrice-de-Sherrington, Saint-Cyprien-de-Napierville, Saint-Bernard-de-Lacolle and Lacolle.
The last part of the route will run along Fairbanks Creek to the Richelieu River, where it will connect with the American network.
Further south, there will be a 545-kilometre link between the Canada-U.S. border and New York City.
Hydro-Quebec is holding two consultations on the project, on Dec. 8 in Lacolle and Dec. 9 in Saint-Jacques-le-Mineur.
Once the route is in service, the Quebec line will be subject to a partnership between Hydro-Quebec and the Mohawk Council of Kahnawake, which will benefit from economic remunerations for 40 years.