View source for Rivière du Sud-Ouest (Saint Lawrence River tributary)

{{short description|River in Canada}}
{{Other uses|Rivière du Sud-Ouest (disambiguation)}}
{{Infobox river
| name               = Rivière du Sud-Ouest
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<!---------------------- IMAGE & MAP -->
| image              = Parc du Bic Accueil.JPG
| image_caption      = Southwest river in [[Bic National Park]]
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<!---------------------- LOCATION -->
| subdivision_type1  = Country
| subdivision_name1  = [[Canada]]
| subdivision_type2  = Province
| subdivision_name2  = [[Quebec]]
| subdivision_type3  = Region
| subdivision_name3  = [[Chaudière-Appalaches]]
| subdivision_type4  = [[Regional County Municipality]]
| subdivision_name4  = [[Montmagny Regional County Municipality]]
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<!---------------------- PHYSICAL CHARACTERISTICS -->
| length             = {{convert|23|km|mi|abbr=on}}
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<!---------------------- BASIN FEATURES -->
| source1            = Lake Saint-Mathieu
| source1_location   = [[Saint-Mathieu-de-Rioux, Quebec|Saint-Mathieu-de-Rioux]]
| source1_coordinates= {{coord|48.172053|68.99442|display=inline}}
| source1_elevation  = {{convert|NNNN|m|ft|abbr=on}}
| mouth              = [[Saint Lawrence River]]
| mouth_location     = [[Rimouski]]
| mouth_coordinates  = {{coord|48.35695|-68.75639|display=inline,title}}
| mouth_elevation    = {{convert|4|m|ft|abbr=on}}
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| tributaries_left   =(Upstream) Rossignol Creek, Lac des Coulombe outlet, Lac Fournier and Lac Caouette outlet, Ernest-Boucher stream.
| tributaries_right  =(Upstream) Morin stream, Beaver stream, Simon stream, Grand Lac Malobès outlet, Cold stream.
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}}
The '''Rivière du Sud-Ouest''' ({{IPA|fr|ʁivjɛʁ dy syd wɛst}}, "River of the South-West") 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 municipality|regional county municipalities]] of:
* [[Les Basques Regional County Municipality]]: municipality of [[Saint-Mathieu-de-Rioux, Quebec|Saint-Mathieu-de-Rioux]];
* [[Rimouski-Neigette Regional County Municipality]]: city of [[Rimouski]] (sector [[Le Bic]]).
== Geography ==
The Southwest river rises in the outlet of Lake Saint-Mathieu (length: {{convert|5.3|m}}; altitude: {{convert|114|m}}), at [[Saint-Mathieu-de-Rioux, Quebec|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 {{convert|18|m}} is located near its mouth.<ref>{{harvnb|Union québécoise pour la conservation de la nature|2004|pp=11–12}}</ref>
The flow of the south-west river is generally slow, its course being located on a plateau whose average altitude is {{convert|105|km}}. The last eight kilometers show more rugged terrain.<ref>{{harvnb|Union québécoise pour la conservation de la nature|2004|p=12}}</ref>
From the mouth of Lake Saint-Mathieu, the southwest river flows over {{convert|7.1|km}} divided into the following segments:
'''Upper course of the river''' (segment of {{convert|12.1|km}})
* {{convert|0.2|km}} towards the northeast, crossing under the bridge of the Ladrière road, to the southwest shore of Petit lac Saint-Mathieu;
* {{convert|2.9|km}} towards the north-east, crossing the full length of Petit lac Saint-Mathieu;
* {{convert|2.3|km}} 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;
* {{convert|1.9|km}} northwards, to the limit of [[Saint-Simon-de-Rimouski]];
* {{convert|2.6|km}} towards the northeast, constituting the limit between [[Saint-Mathieu-de-Rioux, Quebec|Saint-Mathieu-de-Rioux]] and [[Saint-Simon-de-Rimouski]];
* {{convert|0.7|km}} north-east, in [[Saint-Simon-de-Rimouski]], to the road bridge of 2th rang Ouest;
* {{convert|1.5|km}} towards the northeast, forming the limit between [[Saint-Fabien, Quebec|Saint-Fabien]] and the town of [[Rimouski]] (sector [[Le Bic]]);
'''Upper course of the river''' (segment of {{convert|19.4|km}})
* {{convert|7.4|km}} 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: {{convert|2.7|km}}; altitude: {{convert|106|m}}) over its full length, to the dam located to the northeast;
* {{convert|0.6|km}} eastwards, to the bridge of 7th Avenue which crosses the village of [[Saint-Fabien, Quebec|Saint-Fabien]];
* {{convert|2.5|km}} north-east, up to the confluence of the outlet of Grand Lac Malobès;
* {{convert|5.1|km}} north-east, passing under the [[Canadian National]] railway at the start of this segment, to the [[Quebec Route 132|route 132]] bridge;
* {{convert|3.8|km}} towards the north-east, crossing the Bay of Roses and passing under the bridge of Chemin du Petit Portage, to its confluence.<ref>"Atlas of Canada" map, edited by the Department of Natural Resources Canada.</ref>
=== Hydrology ===
The [[Drainage basin|watershed]] has an area of {{convert|192|km2}}.
== Toponymy ==
The toponym "south-west river" was formalized on December 5, 1968 at the [[Commission de toponymie du Québec]].<ref name=CTQ>[http://www.toponymie.gouv.qc.ca/ct/ToposWeb/fiche.aspx?No_seq=61049 Commission de toponymie du Québec - Bank of place names - Toponym: Rivière du Sud-Ouest].</ref>
== Fauna ==
The river hosts a small population of [[Atlantic salmon]] of around 40 spawners.<ref>{{cite book|author=Collectif Ulysse|title=The national parks of Gaspésie and Bas-Saint-Laurent - collection=Ulysse Green Spaces|publisher=Ulysse Travel Guides|year=2008|pages=32–33|isbn=978-2-89464-838-4}}</ref> The latter goes up the river on {{convert|4|km2}} where the fall of {{convert|18|m}} constitutes an insurmountable obstacle. Salmon spend the first two years of their lives in the river.<ref>{{harvnb|Union québécoise pour la conservation de la nature|2004|p=17}}</ref> 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.<ref>{{harvnb|Union québécoise pour la conservation de la nature|2004|p=18}}</ref>
== Notes and references ==
{{Reflist}}
== Appendices ==
=== Bibliography ===
* {{cite book|last1=Union québécoise pour la conservation de la nature|title=Synthesis report: Parc national du Bic|year=2004|pages=91|url=http://www.naturequebec.org/fichiers/Aires_protegees/Rapport_projet_PAPE_PDFMars/Aires_protegees/Bic.pdf}}
=== Related articles ===
{{GeoGroup}}
* [[Saint-Mathieu-de-Rioux, Quebec|Saint-Mathieu-de-Rioux]], a municipality
* [[Saint-Fabien, Quebec|Saint-Fabien]], a municipality
* [[Rimouski]], a city
* [[Neigette River (Les Basques)|Neigette River]], a stream
* [[Bic National Park]]
* [[Rimouski-Neigette Regional County Municipality]]
* [[Les Basques Regional County Municipality]]
* [[St. Lawrence River]]
=== External links ===
{{Portal|Rivers}}
{{DEFAULTSORT:Sud-Ouest, rivière du}}
[[Category:Rivers of Bas-Saint-Laurent]]
[[Category:Rimouski-Neigette Regional County Municipality]]