Skip to main content

Filling the reservoir

Filling the Site C reservoir allows us to put the generating station, spillways, turbines and generators into operation. 

Tunnel conversion

Reservoir size comparison
Prior to filling the reservoir, we installed four large rings in one of the diversion tunnels to restrict the flow of water.

Tunnel conversion, a key step in preparing for reservoir filling, was completed in 2023.

In 2020, two tunnels began diverting the Peace River around the dam site to allow us to build the earthfill dam.

We started the process of tunnel conversion in June 2023. Over the course of 12 weeks, we installed four large rings inside one of the tunnels to restrict the flow of water during reservoir filling.

Tunnel conversion needed to take place between July and September due to environmental, operational, and weather-related constraints as well as construction progress.

Converting the tunnels helps control the flow of water

During the early stages of reservoir filling, water was restricted in the tunnels, causing the water level to rise. When the water was high enough to flow through the spillway, both tunnels were closed.

Flows downstream continued throughout reservoir filling. With reservoir filling complete, the diversion tunnels will be permanently sealed and filled in. 

Resources