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 restore safe operations up to the full reservoir level was chosen as the recommended leading alternative. 

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

Addressing existing deterioration and seismic deficiencies requires extensive upgrade. We’re evaluating how to improve the facility to meet dam safety requirements.

Select the project map [PDF, 1.4 MB] to view it at a larger size.

The La Joie Dam Improvement Project will address dam safety risks arising from its age and ability to withstand a large-scale earthquake. 

To mitigate these risks we adjusted dam operations in 2015 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 manage flows throughout the Bridge system. This is an interim measure until the project is complete.

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.

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.