Covering 145 kilometres (90.10 mi) and forming a large open crescent to the North, "Lac des Quinze" is a major expansion of the Ottawa River.

In addition, "Lac des Quinze" is powered by: After crossing the "Lac des Quinze", the current of the Ottawa River leaves the Baie Perron to flow on 24 kilometres (15 mi) (at the limit of the municipalities of Guérin and from Saint-Eugène-de-Guigues, Quebec) westerly through a series of rapids: Cypress, Kakake, Islands and Fifteen.

The shape of the lake surrounds by the southwest Lac des Quinze Biodiversity Reserve, located in the territory of Laverlochère-Angliers.

This part of the Outaouais is designated in the locality under the name "Les Quinze", which comes from the fact that, to go up in a canoe, it is necessary to make about fifteen portages "(corresponding to as many cascades or falls).

[1] The toponym "Lac des Quinze" (in French) was formalized on December 5, 1968, at the Bank of Place Names of the Commission de toponymie du Québec.