Canada · Industrial projects
How British Columbia’s Site C dam went from approval to first power
BC Hydro’s Site C project received environmental approvals in 2014 and commissioned its last generating unit in August 2025. Diverting the Peace River, filling the reservoir and starting each generator were separate milestones.
Sources checked
- October 2014Environmental approvals
Federal and provincial governments approved the project. Source 1
- July 2015Construction starts
Work began on the Peace River site near Fort St. John. Source 2
- October 2020Peace River diverted
Temporary tunnels carried river water past the construction area. Source 3
- 25 August 2024Reservoir filling begins
BC Hydro reported that the areas needed for filling were ready. Source 2
- October 2024First unit starts generating
The first of the six units came into service while reservoir filling was under way. Source 4
- 8 August 2025Sixth unit commissioned
BC Hydro lists the station as fully operational from this date. Source 1
First generation began in October 2024. All six units were operating by August 2025.
Diverting the river opened the work site
BC Hydro diverted the Peace River in October 2020 and routed it through temporary tunnels so construction could continue around the dam. The utility’s annual report also records that the first of two new transmission lines entered service that month. A generating station needs that connection to send electricity to the grid. Source 3
Filling and generation overlapped
Filling started in August 2024 and finished in November. The first generating unit entered service in October. BC Hydro brought four units into service by the end of March 2025 and announced the commissioning of the sixth in August. The utility still listed finishing work after the station reached full operation. Source 2 Source 6 Source 4
Capacity describes how much power the units can supply
BC Hydro reports more than 1,100 megawatts of generating capacity with all six units available. The station is the third hydroelectric facility on the Peace River. The construction-era name Site C is still used in the older records, while the operating profile uses the John Horgan name. Source 1 Source 4
The review panel recorded costs as well as benefits
The joint panel described benefits from adding electricity supply and flagged the loss of agriculture on the valley bottom and the inundation of archaeological and historic sites. It also found significant cumulative effects on fish, wildlife, heritage and traditional land and resource use when the project was considered alongside other development in the region. Source 5
Sources
- BC Hydro operating profile for the John Horgan Dam and Generating Station
- BC Hydro reservoir filling announcement
- BC Hydro Site C annual report to the British Columbia Utilities Commission
- BC Hydro commissioning announcement
- Federal and provincial Joint Review Panel summary
- BC Hydro 2024 to 2025 service plan report