New Development

Fill ‘er up! Reservoir filling begins on BC’s Site C hydro

It will take two to four months to fill the reservoir of the 1,100 MW/5,100 GWh Site C, which is now more than 85% complete, per BC Hydro.
Fill ‘er up! Reservoir filling begins on BC’s Site C hydro
Site C on the Peace River in northeastern British Columbia is the largest and most expensive infrastructure project in the province’s history – with an estimated construction cost of $16 billion. (image courtesy: BC Hydro)

Crown provincial utility BC Hydro has begun filling the 1.1 GW Site C Clean Energy Project reservoir in northeast British Columbia after completing all necessary construction. Filling the reservoir allows the generating station, spillways, turbine, and generators to begin operating, marking a significant milestone for Site C, which is now more than 85% complete, per BC Hydro.

It will take two to four months to fill the Site C reservoir, as water levels rise between 30 cm and 3 m each day. BC Hydro considered filling the reservoir last fall, one year ahead of schedule, but determined critical work areas needed to be completed first, including Site C’s approach channel, spillway gates and powerhouse intake gates.

Water to fill the Site C reservoir will come from the upstream Williston Reservoir after it is used to generate electricity at both the GM Shrum and Peace Canyon generating stations. BC Hydro assures there’s no reason to worry about whether there’s enough water available because the amount needed to fill Site C’s reservoir is many times less than the annual discharge from Williston Reservoir, even in a drought year. Downstream water flows from Site C will be within BC Hydro’s normal operating range and similar to levels over the past couple of years.

Site C’s first generating unit is scheduled to come into service in December, and the project remains on track to have all six generating units in service by fall 2025, BC Hydro said. Once completed, Site C will be the third dam and hydroelectric generating station on the Peace River in northeast B.C. It will provide 1.1 GW of capacity and produce about 5,100 GWh of electricity each year, adding about 8% more total supply to the local grid. The Site C reservoir will be 83 km long and will cover about 5,550 hectares of land with a total surface area of about 9,330 hectares.

Members of the public are being strongly urged to stay out of the reservoir area during filling and for at least one year after, due to potential hazards including loose soil and vegetation debris. BC Hydro has installed comprehensive warning and danger signs throughout the reservoir area to support public safety, and a notification will be issued when the public can access the reservoir again. Existing boat launches along the reservoir will be closed and opened again once it’s determined to be safe. Updates will be posted on the Site C website.

BC Hydro has been working with local communities and First Nations to prepare for the impact of reservoir filling through engagement activities such as open houses, field tours, commemoration opportunities, and providing community support. Less than 1% of the Class 1 to 5 agricultural land in the Peace Agricultural Region will be affected by building Site C, including the reservoir area. BC Hydro has established a $20 million Peace Agricultural Compensation Fund to support local agricultural production, programs and projects.