The river begins on the slopes of Mount Bélair and the Butte du Petit-Capsa, at the foothills of the Laurentian Mountains, and flows 23.5 kilometres (14.6 mi) before ending in the Quebec City neighbourhood of Cap-Rouge as a left tributary of the Saint Lawrence River.
It is also at the junction of those rivers that is located the archeological site of Charlesbourg-Royal, the earliest known French settlement in North America.

Its 82-square-kilometre (32 sq mi) watershed also encompasses parts of La Jacques-Cartier Regional County Municipality, L'Ancienne-Lorette, La Haute-Saint-Charles and Saint-Augustin-de-Desmaures, where agricultural activities are found and which puts the river at risk of agricultural pollution.
  Measurements of ammoniacal nitrogen, nitrate and phosphorus were however all classified as "good" in 2016.

The main neighboring hydrographic slopes are:
west: the Noire River (rivière aux Pommes) and the Rivière à Matte, in the Neuville sector;
northwest: the Rivière aux Pommes;
south: the slope of Saint-Augustin Lake and the Rivière des Roches;
north: Notre-Dame brook, Lorette River, Saint-Charles River.

On its course, the river crosses the districts: "Le Grand Village", "Quartier Laurentien", Jouvence and Cap-Rouge.
At the end of the route, the river passes under the Tracel de Cap-Rouge, a raised railway bridge operated by the Canadian National.
The river flows into the cove of Cap Rouge in the St. Lawrence River.
In Quebec City, the municipal parks of Champigny, Écores and Lorraine are also located on the banks of the river, in addition to several kilometers of trails.

From its source, the Cap Rouge river flows over 23.9 kilometres (14.9 mi), with a drop of 134 metres (440 ft), according to the following segments:
1.3 kilometres (0.81 mi) eastwards in the forest zone, up to the bridge of Rang Petit-Capsa in Saint-Augustin-de-Desmaures;
3.7 kilometres (2.3 mi) to the southeast, first in the forest zone, then in the agricultural zone by cutting the 4th range west road, the Canadian National railway, the 3rd range west, to Grand-Village stream (coming from the southwest);
5.2 kilometres (3.2 mi) towards the northeast by crossing the 3rd range road (west of the hamlet Le Grand-Village), the Fossambault road, by collecting the Béland stream (coming from the north- west), the Yellow stream (coming from the northwest) and the Bélair stream (coming from the north), and entering the territory of Sainte-Foy-Sillery-Cap-Rouge at the end of the segment, until the Lorette River (coming from the north);
5.9 kilometres (3.7 mi) to the east by forming large streamers where municipal parks are laid out, crossing the chemin du rang Saint-Denis, up to boulevard Wilfrid-Hamel (route 138);
3.4 kilometres (2.1 mi) towards the northeast in an urban area, making a curve to the south and forming several serpentines, crossing the Jean-Gauvin road and the Jules-Vernes avenue, until the highway 40;
4.4 kilometres (2.7 mi) to the south in an urban area, by cutting avenue Blaise-Pascal, rue Provancher, boulevard de la Chaudière, rue Augustin-Bourbeau, the Canadian Pacific Railway bridge and rue Saint-Félix, to its mouth.
The river begins on the slopes of Mount Bélair and the Butte du Petit-Capsa, at the foothills of the Laurentian Mountains, and flows 23.5 kilometres (14.6 mi) before ending in the Quebec City neighbourhood of Cap-Rouge as a left tributary of the Saint Lawrence River. It is also at the junction of those rivers that is located the archeological site of Charlesbourg-Royal, the earliest known French settlement in North America.
Its 82-square-kilometre (32 sq mi) watershed also encompasses parts of La Jacques-Cartier Regional County Municipality, L'Ancienne-Lorette, La Haute-Saint-Charles and Saint-Augustin-de-Desmaures, where agricultural activities are found and which puts the river at risk of agricultural pollution.   Measurements of ammoniacal nitrogen, nitrate and phosphorus were however all classified as "good" in 2016.
The main neighboring hydrographic slopes are:
west: the Noire River (rivière aux Pommes) and the Rivière à Matte, in the Neuville sector;
northwest: the Rivière aux Pommes;
south: the slope of Saint-Augustin Lake and the Rivière des Roches;
north: Notre-Dame brook, Lorette River, Saint-Charles River.
On its course, the river crosses the districts: "Le Grand Village", "Quartier Laurentien", Jouvence and Cap-Rouge. At the end of the route, the river passes under the Tracel de Cap-Rouge, a raised railway bridge operated by the Canadian National. The river flows into the cove of Cap Rouge in the St. Lawrence River. In Quebec City, the municipal parks of Champigny, Écores and Lorraine are also located on the banks of the river, in addition to several kilometers of trails.
From its source, the Cap Rouge river flows over 23.9 kilometres (14.9 mi), with a drop of 134 metres (440 ft), according to the following segments:
1.3 kilometres (0.81 mi) eastwards in the forest zone, up to the bridge of Rang Petit-Capsa in Saint-Augustin-de-Desmaures;
3.7 kilometres (2.3 mi) to the southeast, first in the forest zone, then in the agricultural zone by cutting the 4th range west road, the Canadian National railway, the 3rd range west, to Grand-Village stream (coming from the southwest);
5.2 kilometres (3.2 mi) towards the northeast by crossing the 3rd range road (west of the hamlet Le Grand-Village), the Fossambault road, by collecting the Béland stream (coming from the north- west), the Yellow stream (coming from the northwest) and the Bélair stream (coming from the north), and entering the territory of Sainte-Foy-Sillery-Cap-Rouge at the end of the segment, until the Lorette River (coming from the north);
5.9 kilometres (3.7 mi) to the east by forming large streamers where municipal parks are laid out, crossing the chemin du rang Saint-Denis, up to boulevard Wilfrid-Hamel (route 138);
3.4 kilometres (2.1 mi) towards the northeast in an urban area, making a curve to the south and forming several serpentines, crossing the Jean-Gauvin road and the Jules-Vernes avenue, until the highway 40;
4.4 kilometres (2.7 mi) to the south in an urban area, by cutting avenue Blaise-Pascal, rue Provancher, boulevard de la Chaudière, rue Augustin-Bourbeau, the Canadian Pacific Railway bridge and rue Saint-Félix, to its mouth.
Rivière du Cap Rouge