The structure was created 214 (±1) million years ago, in the Late Triassic, by the impact of a meteorite 5 km (3 mi) in diameter.

[4] Mount Babel is interpreted as the central peak of the crater, formed by post-impact uplift.

[12] The works were part of the enormous Manicouagan or Manic series of hydroelectric projects undertaken by Hydro-Québec, the provincial electrical utility.

The complex of dams is also called the Manic-Outardes Project because the rivers involved are the Manicouagan and the Outardes.

The surface of the lake also experiences low levels in the extreme periods of heat in New England during the summer, since in that period Hydro-Québec sells electrical energy to the joint New England grid and individual utilities in the United States.