FORT ST. JOHN, B.C. – BC Hydro is calling the completion of the roller-compacted concrete program at Site C in October a major milestone.

The program started in 2017, and since then, three large buttresses, or foundations, that support the powerhouse, spillways and the dam have been built utilizing 1.68 million cubic metres of roller-compacted concrete.

In an update earlier this week, BC Hydro says the buttresses are a key component of the dam’s design,  measuring approximately 800 metres long and up to 70 metres wide combined.

The foundations ensure the stability of the dam structures, including in the unlikely event of a major earthquake, said BC Hydro.

“Roller-compacted concrete has many properties similar to conventional concrete, but is constructed with a placement method that makes it well suited for large-scale dam construction. This concrete was manufactured on-site and then transported by trucks to the buttresses.”

The powerhouse buttress was completed in 2018, the upper spillway buttress in fall 2019, and the dam and core buttress in October 2021.

BC Hydro says the buttresses form the second-largest concrete structure in B.C., after its Revelstoke Dam, and the largest roller-compacted concrete dam structure in Canada.

The total volume of the Site C buttress is six times the volume of concrete used to build the Burj Khalifa in Dubai, the tallest building in the world.