The Rivière du Sud-Ouest is a tributary of the southeast coast of the St. Lawrence River. This river flows in the administrative region of Bas-Saint-Laurent, in Quebec, in Canada, in the regional county municipalities of:
- Les Basques Regional County Municipality: municipality of Saint-Mathieu-de-Rioux;
- Rimouski-Neigette Regional County Municipality: city of Rimouski (sector Le Bic).
| Rivière du Sud | |
|---|---|
 Southwest river in Bic National Park | |
| Location | |
| Country | Canada |
| Province | Quebec |
| Region | Chaudière-Appalaches |
| Regional County Municipality | Montmagny Regional County Municipality |
| Physical characteristics | |
| Source | Lake Saint-Mathieu |
| • location | Saint-Mathieu-de-Rioux |
| • coordinates | 48°10′19″N 68°59′40″E / 48.172053°N 68.99442°E |
| Mouth | Saint Lawrence River |
• location | Rimouski |
• coordinates | 48°21′25″N 68°45′23″W / 48.35695°N 68.75639°W |
• elevation | 4 m (13 ft) |
| Length | 23 km (14 mi) |
| Basin features | |
| Tributaries | |
| • left | (Upstream) Rossignol Creek, Lac des Coulombe outlet, Lac Fournier and Lac Caouette outlet, Ernest-Boucher stream. |
| • right | (Upstream) Morin stream, Beaver stream, Simon stream, Grand Lac Malobès outlet, Cold stream. |
Geography edit
The Southwest river rises in the outlet of Lake Saint-Mathieu (length: 5.3 metres (17 ft); altitude: 114 metres (374 ft)), at Saint-Mathieu-de-Rioux. It then follows the St. Lawrence River in a northeast-southwest direction to flow into the Havre du Bic. During its course, it crosses Petit Lac Saint-Mathieu and Lac de la Station. Its two main tributaries are the outlet of Grand Lac Malobès and the Neigette River. A fall from a height of 18 metres (59 ft) is located near its mouth.[1]
The flow of the south-west river is generally slow, its course being located on a plateau whose average altitude is 105 kilometres (65 mi). The last eight kilometers show more rugged terrain.[2]
From the mouth of Lake Saint-Mathieu, the southwest river flows over 7.1 kilometres (4.4 mi) divided into the following segments:
Upper course of the river (segment of 12.1 kilometres (7.5 mi))
- 0.2 kilometres (0.12 mi) towards the northeast, crossing under the bridge of the Ladrière road, to the southwest shore of Petit lac Saint-Mathieu;
- 2.9 kilometres (1.8 mi) towards the north-east, crossing the full length of Petit lac Saint-Mathieu;
- 2.3 kilometres (1.4 mi) towards the northeast, crossing the road to 5th rang, collecting the waters of the Neigette River (Les Basques), up to the route du 3th Rang Est;
- 1.9 kilometres (1.2 mi) northwards, to the limit of Saint-Simon-de-Rimouski;
- 2.6 kilometres (1.6 mi) towards the northeast, constituting the limit between Saint-Mathieu-de-Rioux and Saint-Simon-de-Rimouski;
- 0.7 kilometres (0.43 mi) north-east, in Saint-Simon-de-Rimouski, to the road bridge of 2th rang Ouest;
- 1.5 kilometres (0.93 mi) towards the northeast, forming the limit between Saint-Fabien and the town of Rimouski (sector Le Bic);
Upper course of the river (segment of 19.4 kilometres (12.1 mi))
- 7.4 kilometres (4.6 mi) towards the northeast, in Rimouski, recovering the waters of the outlet of Lac des Coulombe (coming from the north), crossing Lac de la Station (length: 2.7 kilometres (1.7 mi); altitude: 106 metres (348 ft)) over its full length, to the dam located to the northeast;
- 0.6 kilometres (0.37 mi) eastwards, to the bridge of 7th Avenue which crosses the village of Saint-Fabien;
- 2.5 kilometres (1.6 mi) north-east, up to the confluence of the outlet of Grand Lac Malobès;
- 5.1 kilometres (3.2 mi) north-east, passing under the Canadian National railway at the start of this segment, to the route 132 bridge;
- 3.8 kilometres (2.4 mi) towards the north-east, crossing the Bay of Roses and passing under the bridge of Chemin du Petit Portage, to its confluence.[3]
Hydrology edit
The watershed has an area of 192 square kilometres (74 sq mi).
Toponymy edit
The toponym "south-west river" was formalized on December 5, 1968 at the Commission de toponymie du Québec.[4]
Fauna edit
The river hosts a small population of Atlantic salmon of around 40 spawners.[5] The latter goes up the river on 4 square kilometres (1.5 sq mi) where the fall of 18 metres (59 ft) constitutes an insurmountable obstacle. Salmon spend the first two years of their lives in the river.[6] The second species in abundance is generally the American eel, which unlike salmon, goes up the river over its entire length to Lake Saint-Mathieu.[7]
Notes and references edit
- ^ Union québécoise pour la conservation de la nature 2004, pp. 11–12
- ^ Union québécoise pour la conservation de la nature 2004, p. 12
- ^ "Atlas of Canada" map, edited by the Department of Natural Resources Canada.
- ^ Commission de toponymie du Québec - Bank of place names - Toponym: Rivière du Sud-Ouest.
- ^ Collectif Ulysse (2008). The national parks of Gaspésie and Bas-Saint-Laurent - collection=Ulysse Green Spaces. Ulysse Travel Guides. pp. 32–33. ISBN 978-2-89464-838-4.
- ^ Union québécoise pour la conservation de la nature 2004, p. 17
- ^ Union québécoise pour la conservation de la nature 2004, p. 18
Appendices edit
Bibliography edit
- Union québécoise pour la conservation de la nature (2004). Synthesis report: Parc national du Bic (PDF). p. 91.
Related articles edit
- Saint-Mathieu-de-Rioux, a municipality
- Saint-Fabien, a municipality
- Rimouski, a city
- Neigette River, a stream
- Bic National Park
- Rimouski-Neigette Regional County Municipality
- Les Basques Regional County Municipality
- St. Lawrence River
