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New Brunswick utility to spend $3.6B to prolong life of Mactaquac hydro dam

Project to keep 670-megawatt facility west of Fredericton running until 2068, repair swells and cracks in aging concrete



FREDERICTON—After three years of public consultation on the future of New Brunswick’s Mactaquac hydroelectric generating station, the province’s Crown-owned electric utility has decided to spend up to $3.6 billion to prolong the life of the old dam.

The 670-megawatt facility on the St. John River, west of Fredericton, will remain in use until approximately 2068, at which point the facility will be 100 years old, NB Power said Dec 20.

Since the 1980s, concrete portions of the facility have been affected by a chemical reaction called alkali-aggregate reaction. The reaction causes the concrete to swell and crack, requiring substantial repairs and maintenance. It was expected the dam would be decommissioned by 2030.

“Maintaining the station will allow NB Power future flexibility while we meet our financial and environmental targets, and continue to provide safe, reliable energy at low and stable rates,” said NB Power CEO Gaetan Thomas.

The utility has been studying a number of options: rebuilding the spillway and generating station; leaving the dam intact but decommissioning the generators; removing the dam altogether and letting the river return to it’s original course.

However, the chairman of NB Power’s board of directors, Ed Barrett, said that a fourth option became a reality in the last two years.

“We weren’t prepared to cite it as an option because it wasn’t a known option or wasn’t a confirmed option. We credit management in the last two years to be pursuing that around the world to see where … this has been done successfully,” he said.

The project is expected to cost up to $3.6 billion, and would include patching water leaks, repairing damaged concrete and replacing six turbines. The other options would have cost around $5 billion.

Barrett said extending the life of the dam makes good business sense.

“Once you commit to some of the other options, you take off the table some of the options you may want to pursue with green energy. That factored into our thinking as well,” he said.

The New Brunswick Salmon Council had called for the removal of the dam, while area residents say its man-made headpond helps tourism.

Elizabeth Hendriks, spokeswoman for World Wildlife Fund Canada, said she’s disappointed with NB Power’s decision.

“In the short-term, this may be the most affordable decision for taxpayers. But this expenditure will lock us into a future of continued decline of the St. John River ecosystem,” she said.

Hendriks is calling on the utility to share its research with the public.

Louise Comeau, director of climate change with the Conservation Council of New Brunswick, said NB Power has made a responsible decision.

“It’s a green solution in terms of climate change and keeping our greenhouse gas emissions low,” she said. “And there is an investment in fish passage, which is critically important.”

The project includes up to $100 million for the installation of adequate means for fish to traverse the dam.

Allen Curry, science director of the Canadian Rivers Institute, said he thinks it can be done.

“In terms of fish passage for a facility like this, there would have to be multiple ways to get fish up and over. But we also have to think about getting fish back down through the reservoir and back down through these existing turbines,” he said.

Curry said there are 55 species of fish in the river, and 21 of them to get past the dam.

Thomas said the next steps are to seek approvals from the provincial government and the province’s Energy and Utilities Board.

“We will continue to work with the First Nations and to be informed with science. We are going to target multi-species fish passage and we will continue to go through a very rigorous regulatory process—both environmentally and financially,” he said.

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