Power Transmission Projects

315-kV Mauricie–Lanaudière Line

The 315-kV transmission grid in the northeastern metropolitan Montréal and in the Lanaudière region is supplied by lines from Mauricie, Duvernay and Boucherville substations.

As the transmission system developed, the 735-kV and 315-kV grids were interconnected at several locations, rendering them interdependent. This, combined with increased supply demand in the region, has led to overloading problems on some 315-kV lines, particularly those that currently supply Lanaudière substation.

To resolve this situation, Hydro-Québec plans to redesign the 315-kV grid to separate it from the 735-kV system. Part of this plan is for Mauricie substation to replace Duvernay substation as the power source for Lanaudière substation. This will require the construction of a line about 5 km long to connect Lanaudière substation to the existing line from Mauricie substation. When complete, Lanaudière substation will be supplied independently from the metropolitan loop and will be able to rely on Duvernay substation for standby power.

This project is part of Hydro-Québec's plan to upgrade the transmission system in the northeastern metropolitan Montréal.

To learn more about the project, consult the Documents section above.