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Filling the reservoir

One of the last steps in building the Site C dam is to fill the reservoir. Reservoir filling will take about four months, widening the Peace River by an average of two to three times.

Filling the Site C reservoir

Site C reservoir filling is targeted to begin late summer 2024. Filling the reservoir allows us to put the generating station, spillways, turbines and generators into operation, creating enough energy to power the equivalent of about 450,000 homes per year in B.C. When Site C is fully operational, it will generate about 35% of the energy of the W.A.C. Bennett Dam, with just 5% of the reservoir area.

Reservoir size comparison

Boat launches will be closed during reservoir filling and for at least one year after, until the reservoir is deemed safe. Ensuring safety during the gradual filling process and afterwards remains our primary concern. 

What to expect during reservoir filling

Filling the reservoir will create permanent shoreline changes. This is what you can expect as the water level rises:

  • The Site C reservoir will cover 5,550 hectares of land, with a total surface area of about 9,330 hectares.
  • The 83-kilometre-long reservoir will be, on average, two to three times the width of the current Peace River. The mouths of the Moberly River, Halfway River and Cache Creek will also widen.
  • It will take approximately four months for the water to reach its full depth, and the depth will vary: 52 metres close to the dam, 36 metres at Halfway River, and 18 metres near Hudson’s Hope.
  • During reservoir filling, the reservoir will fill at a varying rate of 0.3 metres to three metres per day.
  • The Site C reservoir will be filled using water already stored in and released from the Williston Reservoir. Drought and a below-average snowpack will not affect plans to fill the Site C reservoir in 2024.

Site C reservoir filling process 

Watch the video below to learn more about how we fill the reservoir.

See more videos about reservoir filling, slope stability, boater safety, and more. Watch now →

Timing reservoir filling to protect wildlife

Reducing impacts to wildlife is a top priority during Site C reservoir filling. We’ve taken comprehensive measures to avoid, reduce or offset potential impacts on wildlife in the reservoir area. 

Starting reservoir filling in late summer helps avoid the bird nesting period in spring and summer, the typical spring mammal birthing period, and the winter black bear hibernation period. 

If you see an animal in distress, please contact the B.C. Conservation Officer Service through the Report All Poachers and Polluters (RAPP) Hotline at 1-877-952-7277.

Prerequisites for reservoir filling

The following activities must be complete before reservoir filling can begin:

While filling the reservoir is one of the last activities require to complete the dam, clearing the area began years in advance. We have removed trees and vegetation from the dam site and the reservoir area to ensure boater safety and reduce impacts to dam construction and operations.

Reservoir clearing and debris management activities continue through 2023. This includes road construction, logging, hauling timber to local mills and waste wood burning.

We recognize the importance of this final step, and the impacts on local communities and Indigenous peoples. We’ll continue to communicate expected changes and timing of reservoir filling before it begins with Indigenous Nations and all stakeholders in the Peace Region, including local government and residents.

Prior to filling the reservoir, more than 20 regulatory approvals must be met. In addition to these authorizations, reservoir filling must consider BC Hydro’s operation of the Peace River system, both up and downstream impacts, environmental and weather constraints, as well as the construction progress.

Learn more about how we engage with local communities.



Filling the reservoir factsheet PDF  3.8 MB

 Site C reservoir safety factsheet PDF  4.0 MB