La Joie Dam Improvement Project

Located in St’át’imc Nation Territory, La Joie Dam is at the top of the Bridge River system, significantly influencing the watershed. Parts of the dam are nearing the end of their lifespan and need seismic upgrades to ensure the facility continues to operate safely for the foreseeable future.

After working with St’at’imc Nation and stakeholders to evaluate the alternatives for the project, improving the dam to return to normal reservoir levels was chosen as the recommended leading alternative. 

The project is subject to B.C. Utilities Commission (BCUC) review. 

This scope of work could include extensive upgrades to: 

• The dam
• The intake tower
• Water passage components as required

In 2015, we adjusted dam operations to mitigate seismic risks by reducing Downton Reservoir's maximum elevation from 750m to 734m. This lowered the reservoir's storage capacity by approximately one-half, reducing our ability to buffer large inflows into the La Joie basin, which affects flows throughout the Bridge system.

The La Joie Dam Improvement Project will address dam safety risks arising from its age and ability to withstand a large-scale earthquake. By restoring full capacity of Downton Reservoir, the project will re-establish operating flexibility, benefitting fish and fish habitat throughout the Bridge-Seton watersheds, and meet commitments to St'át'imc Nation. 

BC Hydro's Bridge River system is about 300 km north of Vancouver and includes the La Joie Dam and Powerhouse (Downton Reservoir) near Gold Bridge, in the Upper Bridge River Valley.

Construction activities will likely include:

• Drilling, blasting, and construction equipment.
• Continuous and increased traffic along local roads (large rock trucks, large delivery trucks etc.).
• Traffic control measures to ensure safety.
• Large crews working and support staff.
• Night work, particularly during the winter months.

Select the project map [PDF, 567 KB] to view it at a larger size.

The earliest main works construction could start is 2030. Construction is expected to last about four years. During that time, the area around the dam and quarry is anticipated to become an active construction zone.

St’át’imc Nation consultation and engagement with key stakeholders and the public will be undertaken throughout the project’s lifecycle.

This is an estimate of the project timeline and is subject to change based on the project’s progression. Dates and details on construction activities will be communicated as information becomes available.

We recognize our work can have impacts. That's why we commissioned the La Joie Access and Accommodation Study as part of our upcoming capital project work in the Bridge River System, happening over the next 10 to 15 years.

We're pleased to share with you the report highlights [PDF, 14.3 MB] as well as the full report [PDF, 328.5 MB].

Evaluations of the recommendations in the report are underway.

We thank respondents for participating in the study. Your input will continue to be used as we move further into project planning.

We’re engaging experts from St’át’imc Nation and within BC Hydro to identify potential environmental and heritage risks and mitigation measures for the project.

They’ll be studying aspects such as water quality, fish, wildlife and vegetation, and archaeology.

These efforts will ensure compliance with federal, provincial and St’át’imc Nation standards and agreements.

Periodic reservoir drawdowns are required for construction

During construction, deep drawdowns (periodically lowering the water level) are required to provide crews access to the lower parts of the dam and intake tower.

To achieve a drawdown, instead of storing water in the reservoir, it’s released through the turbine and other outlets throughout the year until the necessary water level is reached. The water then moves through the Carpenter reservoir and the Bridge powerhouses. 

Due to the environmental risks, the project team is prioritizing efforts to minimize the frequency and duration of drawdowns that are below 710 metres. These deeper drawdowns may require approvals from environmental agencies. 

Options for the number and duration of drawdowns are being studied. Once determined, the construction schedule will follow. Safety and environmental management plans during drawdowns will be developed as we get closer to actual construction.

Spring 2022 reservoir drawdown

A deep drawdown of the Downton Reservoir was carried out in spring 2022 which allowed us to complete site investigations at the upstream toe of the dam. 

This work included test pitting and taking samples from the concrete structures as well as environmental and archaeological monitoring to better understand impacts associated with a drawdown.