A new mandate for the Memphrémagog hydroelectric power station, marking 40 years of collaboration

For the past 40 years, our professionals have been working with Hydro-Sherbrooke’s engineering department, carrying out physical and structural assessments, as well as major rehabilitation work on their hydroelectric facilities. Over the years, we have worked on the nine dams/centrifuges owned by this public utility.

The Memphrémagog dam, built in 1920 on the Magog River in the center of the town of the same name, is a class “C” high-capacity dam, whose consequences in the event of failure are considered significant. The complex comprises, from left to right bank, the hydroelectric power station with two turbines, a central junction block, and a spillway consisting of seven gates. Downstream, a dike separates the river on the right from the tailrace on the left. This dam extends some 370 metres downstream.

The power station houses two turbine-generator units, whose water supply is managed via the gates of water intakes located upstream of the power station. The bulk of the work to be carried out under this mandate concerns the restoration of the water intake sector. Other areas to be restored include the left bank upstream, the right bank downstream and the right bank of the central dike downstream of the complex.

Thanks to our in-depth knowledge of the dam, we were able to pinpoint a number of specific tasks and challenges:

• Replacement of embedded parts on intake gates
• Repairs to intake vaults
• Reconstruction of the intake apron (upstream of the downstream rail) and replacement of the grating and upstream rail, and addition of a conduit in the intake apron.
• Removal and reinstallation of debris screens
• Repair of upstream facing, pillars and replacement of intake steel armouring
• Modification of water chamber drain plugs and addition of ladder to water chambers
• Reconstruction of the concrete mass in contact with the bank on the upstream left bank
• Repair of the end of the right wing wall downstream of the spillway
• Repair of the concrete protection on the right side of the central dike and bank stabilization on the left side of the dike
• Design of a protective shelter for the timber beams

A proven partnership for customized rehabilitation

One of the main advantages for Hydro-Sherbrooke of entrusting us with the detailed engineering of this refurbishment mandate lies in our long-standing collaboration with their engineering department, which enables us to fully understand and meet their specific needs. In addition, our in-depth knowledge of the site, the various components of the structure, the available resources and the particular challenges of the project, as well as our experience in similar projects, provide us with invaluable expertise in proposing innovative and appropriate solutions.

Dam rehabilitation mobilizes several disciplines, and our recognized expertise in this field, as well as our ability to diagnose specialized problems, make us the partner of choice for this type of project.

Congratulations to our teams for maintaining the trust of this public utility.