The Saint-Denis River (in French: rivière Saint-Denis) is a tributary of the south-eastern shore of the Kamouraska River, which flows on the south shore of the St. Lawrence river two km to the east of the village center of Kamouraska.
The Saint-Denis river flows on the Côte-du-Sud in the municipalities of Saint-Gabriel-Lalemant, Mont-Carmel and Saint-Bruno-de-Kamouraska, in the Kamouraska Regional County Municipality, in the administrative region of Bas-Saint-Laurent, in province of Quebec, in Canada.
Drawing its source from a marsh area in Saint-Gabriel-Lalemant, near the limit of Mont-Carmel, this watercourse generally flows towards the northeast. This spring is located 16.7 kilometres (10.4 mi) east of the south coast of the St. Lawrence River and 9.4 kilometres (5.8 mi) southeast of the center of the village of Saint-Gabriel-de-Kamouraska.
From its source, the Saint-Denis River flows over 21.9 kilometres (13.6 mi) in a forest and agricultural zone, divided into the following segments:
- 2.8 kilometres (1.7 mi) northward in Saint-Gabriel-Lalemant, up to the confluence of Bras de la Rivière Saint-Denis (coming from the southeast); this 4.0 kilometres (2.5 mi) long arm has its source at Davidson Lake;
- 3.2 kilometres (2.0 mi) northward, to the southern limit of the municipality of Mont-Carmel;
- 2.8 kilometres (1.7 mi) towards the northeast in Mont-Carmel collecting the waters of Anctil brook, up to the route 287 bridge, either between the localities “Grand Bras” and “Bayonne”;
- 3.5 kilometres (2.2 mi) northeasterly, up to the limit of Saint-Bruno-de-Kamouraska;
- 3.5 kilometres (2.2 mi) north-east, to the Petit-Moulin road bridge which crosses the village of Saint-Bruno-de-Kamouraska;
- 4.8 kilometres (3.0 mi) towards the north-west collecting the water from the Bouteillerie River, the Pelletier stream, the Marcel-Dionne stream, the Tardif water, from the Labrie stream, from the Ferré stream, to the Petit-Moulin road, which it crosses again;
- 1.3 kilometres (0.81 mi) westward, curving southward, to its confluence.
This confluence is located at 5.3 kilometres (3.3 mi) south of the village center of Saint-Pascal, at 3.9 kilometres (2.4 mi) north-west of the village center of Saint-Bruno-de-Kamouraska and 5.9 kilometres (3.7 mi) northeast of the center of the village of Mont-Carmel.