Outardes-3

Outardes-3 is a hydroelectric power station and dam on the Outardes River 55 km (34.2 mi) northwest of Baie-Comeau, Quebec, Canada. The power station was commissioned in 1969 and is run-of-the-river.[1][2]

Outardes-3 generating station
Location of Outardes-3 generating station in Canada
Official name	Outardes-3 generating station
Location	Manicouagan Regional County Municipality, Quebec, Canada
Coordinates	49°33′45″N 68°45′08″W
Owner(s)	Hydro-Québec
Dam and spillways
Type of dam	Concrete, gravity
Impounds	Outardes River
Height	250 ft (76 m)
Spillway type	Service, gate controlled
Power Station
Commission date	1969
Type	Run-of-the-river
Turbines	4 x Francis turbines
Installed capacity	1026 MW

Outardes-3 was built in conjunction with the Manicouagan-Outardes project and is located 13 mi (20.9 km) downstream of Outardes-4. Only a 250 ft (76.2 m) high concrete dam was needed to exploit 478 ft (145.7 m) of hydraulic head as the dam raised up water into the existing Lake Tirebouchon. Raising the water in the lake allowed it to rise east near the actual power station 4.5 mi (7.2 km) downstream. Near the eastern portion of the lake, two depressions were filled in with small dikes to withhold the higher lake level, one of which supports a concrete spillway. From the intake on the northern portion of the concrete dam, water is fed via four 750 ft (228.6 m) penstocks towards the underground power station. Water being discharged from the power station enters a 1,488 ft (453.5 m) long and 73 ft (22.3 m) high tunnel before being returned to the river.[3]