A dam and dyke were built to enlarge the existing 213 square kilometres (82 sq mi) Lake-Sainte-Anne reservoir for the use by the Toulnustouc hydroelectric project.

[3] Work started in November 2001, and for the next four years the project employed 425 people on average, peaking at 1,200 workers in the summer of 2003.

[4] The Toulnustouc hydroelectric plant was officially inaugurated on 18 August 2005 by Quebec Premier Jean Charest and Thierry Vandal, CEO of Hydro-Québec.

[1] Submersible tiltmeters were installed along two cross-sectional lines on the dam and the south dike to measure slab deflection so that Hydro-Québec could confirm that any structural movement was within the acceptable range.

[1] The south dyke is in a valley about 500 metres (1,600 ft) southwest of the main dam, and holds back the reservoir in that area.

A geomembrane covered by 35,000 cubic metres (1,200,000 cu ft) of stone stabilizes the slopes and bottom of the discharge channel.