The dam is located about seven miles northeast of the village of Saint-Joseph-de-Mékinac and creates Mekinac tank (corresponding to Mékinac Lake), with a holding capacity 95,317,615 m³.

The main purpose of the Mekinac dam is to regulate the water in Mékinac River and consequently the Saint-Maurice River, down to the hydro-dam of Grand-Mère, Shawinigan and La Gabelle.

Dam built in 2010-2011 From August 2010 until early 2011, the "Mekinac dam", located at the head of the Mékinac River, was completely rebuilt by the construction firm CRT Quebec, which had won the contract from Hydro-Quebec, because this infrastructure was coming to the end of its lifespan.

Vacationers (about 170 chalets in the area), campers and boaters saw then floats settle on the sandy beaches.

The dam has a spillway located in its center, built of steel girders and concrete.