NB Power eyes cheaper refurbishment plan for Mactaquac dam
Gaëtan Thomas says the hydro dam could be refurbished while it is still operating
NB Power is studying the possibility of utilizing new technology so that it can refurbish the Mactaquac Generating Station near Fredericton, while the dam is still operating.
He said the new option could allow engineers to replace parts of the dam, while it is still working, and avoid the construction of a new dam.
“That is an option that is worth considering. Some other areas have done it and we need to really consider whether that is a possibility with the amount of expansion that we have had at the station,” he said.
“We don’t know if that is a full option.”
NB Power needs to replace the Mactaquac dam by 2030 due to a condition known as alkali aggregate reaction that has been causing the dam's concrete structures to expand. According to a NB Power document from earlier this year, the dam is 20 centimetres taller and it is 61 centimetres wider than when it was built.
The Crown corporation stated earlier this week that it has started evaluating three options for replacing the dam and its hydro generation capacity of 668 megawatts.
The options include removing the dam, replace the spillway and maintain the headpond but stop generating power or repower the dam by replacing the spillway and powerhouse.
The cost of refurbishing the dam could reach as high as $5 billion, NB Power said its 10-year financial and capital investment plan, which was filed with the Energy and Utilities Board.
Cheaper option
The NB Power president said he doesn’t want to “set any hopes high” about the possibility of the option of rebuilding parts of the dam as it is still in operation. But he said, if it is determined that it could be feasible, it would have several advantages
“You could delay the work over a longer period. It would be certainly cheaper, it would be possibly around $2. 5 to $3 billion,” he said.
“We don’t know at this stage because we haven’t designed or we haven’t found the solution yet. But we have top-notch engineering firms, working on this. We will know more, like I say, in two years.”
He said this potential option would also require a different environmental impact assessment to be completed.
NB Power intends to have a preferred option in front of the provincial government by 2016. Thomas said construction would likely need to start around 2020.
Thomas said the Crown corporation is taking its time to talk to people who will be affected by whatever decision is eventually made on the hydro dam.
“At the end of the day, we are going to be looking at all options and when you look at the higher number, other alternatives may become better,” he said.
“What we are doing is we are continuously seeking input from our stakeholders all along the river. We have to understand all the environmental and socioeconomic implications.”