| Rivière du Gouffre Sud-Ouest | |
| Subdivision Type1: | Country |
| Subdivision Name1: | Canada |
| Subdivision Type2: | Province |
| Subdivision Name2: | Quebec |
| Subdivision Type3: | Region |
| Subdivision Name3: | Capitale-Nationale |
| Subdivision Type4: | Regional County Municipality |
| Subdivision Name4: | Charlevoix Regional County Municipality |
| Subdivision Type5: | Unorganized territory and municipality |
| Subdivision Name5: | Lac-Pikauba and Saint-Urbain |
| Length: | 29.5km (18.3miles) |
| Source1: | Prime Lake |
| Source1 Location: | Lac-Pikauba |
| Source1 Coordinates: | 47.7276°N -70.6148°W |
| Source1 Elevation: | 724m (2,375feet) |
| Mouth: | Rivière du Gouffre |
| Mouth Location: | Saint-Urbain |
| Mouth Coordinates: | 47.6547°N 70.4419°W |
| Mouth Elevation: | 206m (676feet) |
| Tributaries Left: | (from the mouth) Discharge of two small lakes, Bergeron stream, stream, discharge of several small lakes, stream, stream, outlet of Lac du Gros Castor, outlet of Lac de la Truite. |
| Tributaries Right: | (from the mouth) Discharge from Lac aux Blueuts, two streams, stream from Mouches. |
The Rivière du Gouffre Sud-Ouest (English: South-West Pit Cave River) is a tributary of the eastern bank of the intermediate part of the Rivière du Gouffre, flowing in the unorganized territory of Lac-Pikauba and the municipality of Saint-Urbain, in the Charlevoix Regional County Municipality, in the administrative region of the Capitale-Nationale, in the province of Quebec, in Canada.
The lower and middle parts of this valley are served by a secondary forest road. Forestry is the main economic activity in this valley; recreational tourism, second.
The surface of the Gouffre Sud-Ouest river is generally frozen from the beginning of December until the beginning of April; however, safe circulation on the ice is generally done from mid-December to the end of March. The water level of the river varies with the seasons and the precipitation; the spring flood generally occurs in April.
The Gouffre Sud-Ouest river takes its source from Prime lake (length: ; altitude:) located in forest area and encased in the mountains. The mouth of this lake is located at the bottom of the bay southeast of the lake, either:
From Prime Lake, the course of the Gouffre Sud-Ouest river descends on in a generally deep valley, with a drop of, depending on the segments following:
The Rivière du Gouffre Sud-Ouest flows downstream from a river loop on the west bank of the Rivière du Gouffre, in the municipality of Saint-Urbain. This mouth is located at:
From the mouth of the Gouffre Sud-Ouest river, the current descends on with a drop of following the course of the rivière du Gouffre which flows into Baie-Saint-Paul in the St. Lawrence River.[1]
According to research carried out in cartography, this toponymic designation appears on the regional map of the Ministry of Lands and Forests, 1915 edition. This designation also appears on regional map number 3-Est, 1943. The toponymic variants of this watercourse are: North-West Arm, South-West Arm, North-West of Rivière du Gouffre, Rivière Croche and Rivière du Gouffre North-West.
The toponym "Rivière du Gouffre Sud-Ouest" was formalized on December 5, 1968 at the Place Names Bank of the Commission de toponymie du Québec.[2]