The main civil works contract comprises the majority of earthworks required to construct the Site C project, including:

• Approximately 32 million cubic metres of excavation for structures, including the approach channel and tailrace
• River diversion works, including construction of two 10.8 metre internal diameter concrete-lined tunnels between 700 metres to 800 metres in length, and associated cofferdams and intake and outlet structures
• Earthfill dam – central core zoned earth embankment approximately 1,050 metres long and 60 metres above the present river level.
• Roller-compacted concrete buttress – approximately 800 m in length to a maximum height of 70 m
• Significant ancillary works such as permanent network of site roads, site drainage and debris handling facilities