| Rivière à Idas | |
| 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: | City |
| Subdivision Name5: | Baie-Saint-Paul |
| Length: | 8.4km (05.2miles) |
| Source1: | Lac à Idas |
| Source1 Location: | Baie-Saint-Paul |
| Source1 Coordinates: | 47.4242°N -70.72°W |
| Source1 Elevation: | 884m (2,900feet) |
| Mouth: | Bras du Nord-Ouest |
| Mouth Location: | Baie-Saint-Paul |
| Mouth Coordinates: | 47.4033°N 70.6358°W |
| Mouth Elevation: | 402m (1,319feet) |
| Tributaries Left: | (from the mouth) Stream, discharge from a small lake. |
The rivière à Idas (English: Idas River) is a tributary of the north bank of the upper part of the Bras du Nord-Ouest, flowing entirely in the town of Baie-Saint-Paul, in the Charlevoix Regional County Municipality, in the administrative region of Capitale-Nationale, in the province of Quebec, in Canada.
This valley is mainly served by a forest road going up the right bank of the watercourse, as well as by the chemin du rang de Saint-Placide Sud. Forestry is the main economic activity in this valley; recreational tourism, second.
The surface of the river in Idas 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 Idas river rises at the mouth of Idas Lake (length: ; altitude:). The mouth of this landlocked lake is located at the bottom of a bay east of the lake, either:
From this mouth, the Idas river descends on perpendicular to the shore of the St. Lawrence River, with a drop of, according to the following segments:
The Idas river flows on the north bank of the Bras du Nord-Ouest, in the city of Baie-Saint-Paul. This mouth is located at:
From the mouth of the Idas river, the current descends on following the course of the Bras du Nord-Ouest; then 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]
This toponymic designation appears on the map "Domaine forestier du Séminaire de Québec", 1955–01. It also appears on the cards of the Ruisseau du Pied du Mont number 309 and Lac des Fourches number 308 clubs of the Séminaire de Québec. This toponym evokes the memory of a hunter who once frequented the area. Toponymic variants of the official name: Bras de Saint-Joseph, Bras Saint-Joseph, Bras Saint-Placide, Discharge from the Idas Cup.
The toponym “Rivière à Idas” was formalized on March 25, 1997, at the Place Names Bank of the Commission de toponymie du Québec.[2]