Canada’s top court won’t hear an appeal from two B.C. First Nations worried that construction of an $8.8-billion hydro-electric dam would violate their constitutionally protected treaty rights.

Prophet River First Nation and West Moberly First Nation have been fighting the B.C. government in court for more than two years, hoping to halt construction of the Site C project.

After losses at both the provincial court and Federal Court level, the Supreme Court refused to grant the First Nations leave to appeal.

Site C will flood more than 5,500 hectares of land along the Peace River in northeast B.C., creating an 83-kilometre-long reservoir and providing enough power to light up 450,000 homes a year.

Project construction started in the summer of 2015 and is scheduled for completion in 2024.

A review of the project concluded that there would be significant adverse environmental effects, impacting indigenous treaty rights in the area, but the previous Conservative government ruled it was justified.

The Canadian Press