Outardes-4 is a

hydroelectric Hydroelectricity, or hydroelectric power, is Electricity generation, electricity generated from hydropower (water power). Hydropower supplies 15% of the world's electricity, almost 4,210 TWh in 2023, which is more than all other Renewable energ ...

power station A power station, also referred to as a power plant and sometimes generating station or generating plant, is an industrial facility for the electricity generation, generation of electric power. Power stations are generally connected to an electr ...

and

dam A dam is a barrier that stops or restricts the flow of surface water or underground streams. Reservoirs created by dams not only suppress floods but also provide water for activities such as irrigation, human consumption, industrial use, aqua ...

on the Outardes River northwest of

Baie-Comeau Baie-Comeau () is a city in the Côte-Nord region of the province of Quebec, Canada. It is located on the shores of the St. Lawrence River, and is the seat of Manicouagan Regional County Municipality. It is near the mouth of the Manicouagan Ri ...

Quebec Quebec is Canada's List of Canadian provinces and territories by area, largest province by area. Located in Central Canada, the province shares borders with the provinces of Ontario to the west, Newfoundland and Labrador to the northeast, ...

Canada Canada is a country in North America. Its Provinces and territories of Canada, ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, making it the world's List of coun ...

. The power station was commissioned in 1969 and is supplied by the Outardes-4 Reservoir which is created by seven additional dams.

Construction

Outardes-4 was built in conjunction with the Manicouagan-Outardes project and is the northernmost power station on the Outardes River. Construction on the diversion tunnel for the Outardes River began in September 1964 and was finished in April 1965. A

cofferdam A cofferdam is an enclosure built within a body of water to allow the enclosed area to be pumped out or drained. This pumping creates a dry working environment so that the work can be carried out safely. Cofferdams are commonly used for constru ...

was constructed upstream to direct the river into the diversion tunnel; none was built downstream because the river's grade was sufficient. Once the river was diverted, work commenced on Dam No. 1's foundation. Workers and engineers cleared

alluvial Alluvium (, ) is loose clay, silt, sand, or gravel that has been deposited by running water in a stream bed, on a floodplain, in an alluvial fan or beach, or in similar settings. Alluvium is also sometimes called alluvial deposit. Alluvium is ...

material from the riverbed but ran into uplift faults and pot-holes. Around six pot-holes with to diameters and up to deep had to be excavated, partly by hand. Eventually, those under the dam's foundation were filled in with concrete.

Dams

The Outardes-4 Reservoir is impounded by eight different dams. The main dam is Dam No. 1 and is a rock-fill, earthen

embankment dam An embankment dam is a large artificial dam. It is typically created by the placement and compaction of a complex semi-plastic mound of various compositions of soil or rock. It has a semi-pervious waterproof natural covering for its surface ...

along with Dam No. 2. The six other dams are saddle and auxiliary dams; one is rock and earth-fill, four are earth-fill dikes and one serves as a controlled concrete

spillway A spillway is a structure used to provide the controlled release of water downstream from a dam or levee, typically into the riverbed of the dammed river itself. In the United Kingdom, they may be known as overflow channels. Spillways ensure tha ...

. Dam No. 1 is long and high and made of of material while the second largest dam, No. 2 is long and high. Dam No. 2 is located north of No. 1 on a side-valley is made of of material. Water from the reservoir helps regulate river flow and power generation at the downstream Outardes-3 and Outardes-2 power stations.

Power station

The Outardes-4 power station is located on the west bank of the Outardes River, adjacent to Dam No. 1. Four long, wide penstocks deliver water from the reservoir to each of the power station's turbines. The power station was commissioned in 1969 and currently has a 785 MW capacity. The power station's turbines were rehabilitated in 2009 which had increased generation capacity by 56 MW.

Notes

References

* {{citation , publisher = Hydro-Québec , last1 = Paradis , first1 = Paul , title = Manic-Outardes , location = Montreal , year = 1967. Dams in Quebec Manicouagan-Outardes hydroelectric project Dams completed in 1969 Energy infrastructure completed in 1969 Dams on the Outardes River Publicly owned dams in Canada

Construction

Dams

Power station

See also

Notes

References