NS Power hydro dam rebuild $14M over budget

The hard-luck rebuild of the Nova Scotia Power Tusket River hydro dam in Yarmouth County is now $14 million over budget — a 77 per cent increase over what was approved by regulators three years ago.

Refurbishing the crumbling 92-year-old dam was supposed to cost $18 million.

This week, the company told the Nova Scotia Utility and Review Board the current forecast is $32 million.

The project is also considerably behind schedule, with construction of the new main dam on hold pending federal and provincial permits before it can lower lake reservoirs.

Nova Scotia Power said construction of the main dam is expected to resume in July 2021.

In its 2017 timeline, the refurbished 2.7-megawatt hydro dam was supposed to be operational by the end of 2019.

So what went wrong?

During construction, cracks were discovered in the bedrock below the dam that allowed water into the construction zone. Nova Scotia Power tried an underwater concrete pour and walled off an area in a bid to keep the construction area dry.

But water continued to migrate into the worksite, forcing the company to change plans and seek permission to draw down lake reservoirs behind the dam in order to continue construction.

At some point, the utility will present a final cost estimate to the utility and review board and seek what is known as an authority to overspend — bureaucratic speak for sticking ratepayers with the bill.

The amount will be spread out over time so rates will not be directly impacted.

Consumer advocate Bill Mahody told CBC News he's not prepared to comment on the Tusket project until Nova Scotia Power applies for authority to overspend.

"The escalating costs of hydro refurbishments is a general concern," Mahody said in an email.

Nova Scotia Power responds

Utility spokesperson Jacqueline Foster said the existing dam remains safe for local residents and regular inspections will continue.

"We will continue to engage with local residents, the Mi'kmaq, and other stakeholders as we move forward with construction plans for next summer," she said. 

"We will provide residents with an updated timeline once the project work plan has been confirmed."

The plan to draw down the lakes has triggered the need for a raft of government approvals; from the Department of Fisheries and Oceans over fish migration to Transport Canada over impact on navigable waters.

The plan also needs permission from the provincial Department of Communities, Culture and Heritage for its potential to uncover archeological artifacts and from the Environment Department for its impact on water levels.

And the persistent water migration problem is not the only showstopper. The lake drawdown has also triggered more consultations with the Mi'kmaq.

Engagement was already the source of a major delay after the review board halted proceedings on the grounds the provincial government had not adequately consulted with First Nations on the project.

It's not the only hydro project lagging behind and racking up bills.

The Gaspereau River hydro refurbishment has an even longer, twisted — and more expensive — history.

That project was approved in 2007 at a cost of $4 million.

Nova Scotia Power is currently before the review board asking that ratepayers pick up an additional $18 million in overspending.

In this case, it was the discovery of 21 archeological sites and 300,000 artifacts.

"The archeological discoveries, Mi'kmaq engagement, and revisions to dam designs — which led to the requirement to seek authorization to overspend on this project — are unprecedented," Nova Scotia Power told regulators.