The Rivière Portneuf is a tributary of the north shore of the Saint-Laurent river, crossing the municipalities of Saint-Raymond, Cap-Rouge, Sant-Basile and Portneuf, in the Portneuf Regional County Municipality, in the administrative region of the Capitale-Nationale, in the province of Quebec, in Canada. The Portneuf river valley is mainly served by route 138, chemin Neuf, chemin du rang Saint-Angélique, chemin du Grand Rang, chemin de Bourg-Louis, chemin de la Grande Ligne and chemin du Lac Sept-Îles-Sud. Except for the segments passing through a hamlet of Saint-Raymond, in the village of Saint-Basile and in the village of Portneuf, agriculture and forestry constitute the main economic activities of the sector. The surface of the Portneuf River is generally frozen from the beginning of December to the end of March; safe circulation on the ice is generally done from the end of December to the beginning of March. The water level of the river varies with the seasons and the precipitation.
Geography
The Portneuf River is located on the north shore of the Saint-Laurent river, halfway between Trois-Rivières and Quebec, more precisely between the hydrographic slopes the Sainte-Anne River and the Jacques-Cartier River. The Portneuf River draws its source from Sept Îles Lake which discharge from the southwest. The resort area is very dense around this lake. From the mouth of Lac Sept Îles, the current of the Portneuf River descends on, with a drop of, according to the following segments: Upper course of the Portneuf river
to the south by crossing the Lac-Sept-Îles road, in a valley initially encased between the mountains of two lakes, one of which includes Cantin beach;
south-east passing north-east of Paquet Airport, crossing the Chemin de la Grande Ligne, to the outlet of two small unidentified lakes;
a priori towards the south in an agricultural zone, then towards the south-east bypassing a mountain whose summit reaches and passing through Bourg-Louis where the course makes streamers, up to a bend in the river;
to the southwest by crossing Bourg-Louis Falls, then by tracing streamers in the forest area; then branching south-east where the course crosses Chemin de la Traverse, to the outlet of Lac Sergent;
towards the south-east by collecting a stream, crossing a long series of rapids and forming a loop towards the south-east at the end of the segment, until boulevard Nord-Dame ;
towards the south-west by winding intermittently by collecting the Morasse stream, until the outlet of the Saint-Jacques River ;
to the southwest by forming a first loop to the north, bypassing the village of Saint-Basile-Sud to the east and south and crossing the boulevard du Centenaire, until 'at the confluence of the Chaude River ;
towards the southwest by forming a hook towards the west, then a second towards the east, passing under the Bishop bridge, collecting the stream from rang Saint-Charles and the brook at Jess's, then passing through Portneuf-Station and Portneuf, cutting highway 40, route 138 and the path of iron to its mouth.
Some infrastructures have been erected in this hydrographic slope notably mills and shipyards. Two disused dams are listed in the municipalities of Portneuf and Notre-Dame-de-Portneuf. A quay of one km in length, was built on the Saint-Laurent river during the years 1956 to 1958 by the city of Portneuf west of the mouth of the Portneuf river. This Portneuf wharf points southeast toward Pointe-Platon, located on the south shore of the St. Lawrence River. This quay is a gathering place for local festivities.
Toponymy
The name of this river is linked to the seigniory of Portneuf which it crosses before flowing into the Saint Lawrence river. Although this seigniory was allotted in 1636, the act of the concession was confirmed in 1647. The toponym "Rivière Portneuf" was formalized on December 5, 1968 at the Place Names Bank of the Commission de toponymie du Québec.