The contract could be worth about C$1.5bn ($1.13bn) for Peace River Hydro Partners consortium which include Acciona Infrastructure Canada, Petrowest and Samsung C&T Canada.
The civil works include building an earthfill dam, two diversion tunnels and a concrete foundation for the generating station and spillways.
British Columbia Premier Christy Clark said: "The Site C project is creating thousands of jobs for our province, as well as significant opportunities for apprenticeships, skills training, and business contracts.
"As B.C.’s diverse economy continues to grow, Site C is part of our vision to meet long-term energy needs, providing clean, renewable and affordable electricity for generations."
Estimated to cost around C$8.3bn ($6.23bn), the project is expected to create around 8,000 jobs over the eight-year contract.
Expected to have an operational life of 100 years, the hydro power project is designed to generate clean energy required to power around 450,000 homes annually.
Petrowest president and chief executive officer said: "Peace River Hydro Partners are excited to be part of building a legacy project that will benefit British Columbians for generations to come.
"We look forward to working closely with local workers and First Nations communities to maximize the economic opportunity for families in the Peace region."
Ratepayers would save an average of $650m to $900m annually over the first 50 years of operational life of the project.
BC Hydro also plans other construction contracts for the project including turbines and generators, generating station and spillways, Highway 29 realignment, and substation and transmission lines.
Image: Illustration of Site C project. Photo: courtesy of courtesy of Acciona.
