The Taltson hydroelectric power plant in the Northwest Territories will not be taken offline until early 2025 – more than a year later than originally planned. The cost of overhauling the plant has now risen from around $60 to $70 million to $97 million.

The delay is due to mechanical problems discovered during an overhaul of the 60-year-old facility.

In a news release Wednesday, Northwest Territories Power Corp. said the project had already been delayed previously because the site had to be evacuated for seven weeks due to wildfires in 2023. The further delay was due to a “significant alignment issue within the plant” that must be resolved before the plant can resume operations. The problem was identified earlier this year.

“Engineers and hydropower experts from both the Northwest Territories Power Corporation (NTPC) and outside sources have been working to resolve the issue over the past few months without success,” the press release said.

To fix the problem, the plant now needs to be dismantled. This is expected to take about five months. According to NTPC, the plant is planned to be operational again by January.

The Taltson Hydroelectric Plant is located about 40 miles north of Fort Smith and was built in 1965. In April 2023, NTPC began an overhaul to replace the 59-year-old hydroelectric plant’s major components, such as the generator and turbine.

The hydroelectric communities in South Slave have been powered by diesel generators since the Taltson rehabilitation began. These communities – Fort Smith, Fort Resolution, Hay River, Enterprise and K’atl’odeeche First Nation – will continue to run on diesel until the hydroelectric plant is repaired.

The new $97 million price tag for the work includes the cost of fuel to power these communities, and NTPC’s customers will help pay for that cost. NTPC said that will be partially reflected in the company’s next General Rate Application.

“Full cost recovery will be spread over a longer period of time, so today’s customers are not expected to bear all of the costs of a project that will provide reliable electricity for many decades to come,” the press release said.