The Mégiscane River is one of the most important rivers in the region of Abitibi-Témiscamingue. It has the reputation of being a privileged place to fish for sturgeon. Forestry is the main economic activity of this watershed; recreational tourism activities come second. The surface of the river is generally frozen from mid-December to the end of April.
Geography
The Mégiscane River rises at the mouth of Lac Françoise. This lake is located on the east side of Barrot Lake, at:
east of the confluence of the Mégiscane River with Parent Lake.
In its upper part, this river first runs in Senneterre, then in La Tuque, along the northern boundary of the administrative region of Abitibi-Témiscamingue, where it crosses the lakes of Poète, Rivas and Tête. The current of this river then returns in Senneterre and crosses in particular the lakes Pascagama, Canusio, Mégiscane Lake, Berthelot and Faillon. This river ends in Parent Lake not far from Senneterre. In total, it travels with an average flow of 392 m³/s. Upper Mégiscane River From the mouth of Lake Francoise, the Mégiscane River flows over:
to the north, crossing Lake Oublié and Lake Chassiagne, on, passing east of Eagle Mountain ;
to the north, crossing Lake Tower on its full length. Note: The summit of Fireguard Mountain, located west of Lake Tower, reaches ;
to the north, crossing Lake Bouillet and the southern part of Angéline Lake ;
East, crossing the northern part of Lac Bonhomme on ;
to the North, then the North-East by cutting the boundary between Abitibi-Témiscamingue and Mauricie, to the South shore of "Rat d'Eau Lake" . Note: This lake receive on its East shore the water coming from Provancher Creek;
to the North in Mauricie, crossing the "Rat d'Eau Lake" which is formed by the widening of the river;
west, then north in Mauricie crossing Poète Lake. Note: The "Barrage de la Mégiscane", a Hydro-Québec dam, was built in 1954 in earth material at the outlet of Du Poète Lake . With a length of and a height of, this dam can hold up to 7 590 000 000 cubic meters of water. This dam has five infrastructures including two dikes and three dams. It was designated "Mégiscane Dam" until September 18, 2002; then, the Mégiscane dam. An auxiliary weir has been built on the east side of the lake, which empties into the Gouin Reservoir. It was once called "Barrage Mégiscane", up to September 18, 2002; then, "Barrage de la Mégiscane". A second dam was built at the auxiliary weir which empty toward Gouin Reservoir.
Intermediate course of the Mégiscane River From the mouth of "Lac du poète", the Mégiscane River flows over:
to the North in Mauricie, crossing the lake Rivas ;
to the North, crossing the Head Lake ;
to the North, then to the South-West by cutting the eastern limit of Abitibi-Témiscamingue, until the confluence of the outlet of Bernier Lake and the mouth of Suzie River;
northwesterly, then southwesterly, across the southern part of Pascagama Lake ;
southwesterly to the confluence of the Kekek River ;
to the North, crossing Ouiscatis Lake on ;
southwesterly, then north, crossing the Canusio Lake ;
southwesterly, then northwesterly, crossing the Mégiscane Lake ;
Intermediate course of the Mégiscane River From the mouth of Mégiscane Lake, the Mégiscane River flows over:
southwesterly, crossing the Berthelot Lake. Note: Berthelot Lake receives on the South side the waters of the Berthelot River and on the North side, Macho River;
southwesterly to the bridge over the river, just upstream of Hubert Creek ;
southwesterly to the northeastern shore of Faillon Lake;
southwesterly, crossing the Faillon Lake on its full length, to its mouth. Note: The forest road crosses the bridge at the mouth of the lake to connect the road junction of the north shore of the lake.
Lower Mégiscane River From the mouth of Faillon Lake, the Mégiscane River flows over:
southwesterly to the confluence of the Collin River ;
towards the South-West, until a first fall;
southwesterly, cutting the Canadian National Railway, until a second fall;
southwesterly, forming a southerly curve in a marsh zone to Signay Brook ;
northwesterly, forming a southerly curve through a marsh zone to the Canadian National Railway;
to the northwest, cutting a forest road, to the confluence of the river.
The Mégiscane River flows on the east shore of Parent Lake between two strips of land that extend westward into the lake at:
north of downtown Senneterre;
south of the mouth of Parent Lake ;
south of the confluence of the Brassier River with Parent Lake.
Toponymy
Its name, like that of the lake, derives from the Algonquin metshishkan or mesiskine and means hook, with reference to its quality as a fishing spot. An 1898 map of the province of Quebec mentions the "Mekiskan River" to designate this watercourse. A geological map dated 1935 refers rather to the name "Monet River". The toponym "Mégiscane River" was formalized on December 5, 1968, at the Commission de toponymie du Québec.
Hydropower generation
During the 1940s and 1950s, the Shawinigan Water and Power Company, which held the water power concession of the Saint-Maurice River, conducted several studies to evaluate the potential diversion of rivers to its rivers with hydroelectric plants. After several hesitations, the Government of Quebec authorizes the partial diversion of the Mégiscane to the Saint-Maurice River basin in 1951. The dam was built in 1954 in the municipality of La Tuque, in Mauricie. A second dam and a canal sometimes serve to partially divert the flow of the river to feed the Gouin reservoir and the hydroelectric dams of the Saint-Maurice River. This project was carried out in parallel with the installation of additional turbines at the Rapide-Blanc, Trenche and La Tuque. The total cost of the project, which has increased the company's installed capacity of , is estimated to $14 million.
