Water intake
The water intake leads to the three penstocks. It has three gates to block water flow to
each of the generating units, if necessary. Each opening has a trashrack that keeps debris from getting into the
penstocks.
| Number of gates |
3 |
| Gate dimensions |
10 m high
6.1 m wide |
| Number of stoplogs |
1 stoplog guard gate |
| Number of trashracks |
3 |
| Top elevation of concrete lining |
286.61 m |
| Bottom elevation of concrete lining |
249.31 m |
Penstocks
The penstocks are concrete-lined conduits excavated in the rock. They channel water from the reservoir
to the powerhouse turbines, and are designed to maximize the head (drop in level).
| Dimensions of concrete-lined penstocks |
7.9 m in diameter
108 m long |
| Dimensions of steel-lined penstock sections |
6.85 m in diameter
42.1 m long |
Powerhouse
 The
surface powerhouse, built into a rocky hill, is on the left bank of the Eastmain River, less than three kilometres from the
workcamp. It will house three vertical-axis generating units.
By the time the water exits through the tailrace, it will have dropped 63 m from the water intake. This head,
combined with the flow, develops kinetic energy that causes the turbines and generators to turn, producing electricity.
The electricity will be transmitted by a 315-kV power line to Nemiscau substation, located about 70 km south of the powerhouse.
| Type |
Surface |
| Dimensions |
46 m high
125 m long
55 m wide |
| Head (drop) |
Minimum: 63 m; Maximum: 72 m |
| Generating units |
3 vertical-axis Francis turbines |
| Generator speed |
120 revolutions per minute |
| Rated design flow |
840 m3/s |
Tailrace
The tailrace returns the water exiting from the powerhouse turbines to the Eastmain River.
| Dimensions |
Variable height
30 m wide
900 m long |
|
