image description
Print Friendly

Muskrat Falls Generating Facility

Construction on the generation facilities advanced significantly in 2016. Approximately 58 per cent of the generation project construction was complete at the end of the year.

In 2016, at the Muskrat Falls hydroelectric site in Labrador, extensive progress was made on concrete placement for the powerhouse and intake structures. In August, the spillway gates were safely and successfully raised, opening the spillway and redirecting the flow of the lower Churchill River at Muskrat Falls for the first time. Following the completion of the temporary cofferdams in early November, the river impoundment process commenced for the Muskrat Falls reservoir. The stabilization work on the North Spur dam was substantially completed at the end of the year.

Two dams will be constructed at Muskrat Falls: the north dam (about 34 m high and 430 m long) and the south dam (about 20 m high and 243 m long). The north dam will be constructed using a special high-density concrete, known as roller-compacted concrete (RCC).  The concrete mix is spread by bulldozers, and then compacted by compaction rollers into a series of horizontal layers.  The south dam will be a conventional rock-filled dam that will be constructed by building up layers of rock and till material on the underlying bedrock, which will serve as a foundation for the dam. A road will also be built at the top of the dam to provide access.

The powerhouse will consist of four units, each housing a turbine and generator. The powerhouse/intake structure will be approximately 85m high once constructed. The spillway was put into operation in August 2016. The primary function of the spillway is to release water in the reservoir that isn’t required to generate electricity. The spillway has five bays with gates that can be opened and closed as necessary to control the release of water. The spillway is approximately 40 m tall and 75 m wide.   

The area north of the river forms a natural dam. This area, known as the North Spur dam, has been stabilized as part of the work undertaken at Muskrat Falls.  Stabilization activities were completed on the upstream and downstream of the North Spur dam and included: regarding slopes for stability; excavating and removing high sensitivity clay and the sandy, silty and clayey soils; installing cement-bentonite cut off walls down to the lower clay layer; building protective rock berms along the shoreline; installing drainage and relief wells; and, installing monitoring equipment. This work began in 2014 and was substantially completed at the end of 2016. For a presentation on the North Spur dam please click here