Hydro-Québec opens Nunavik area spillway

The red marker indicates the location of the Duplanter spill-way, which controls the release of water flowing from the Caniapiscau reservoir into the Caniapiscau River, a tributary of the Koksoak River. (IMAGE COURTESY OF GOOGLE MAPS)

Hydro-Québec says it has begun a controlled dam release from its Caniapiscau reservoir in northern Quebec to help manage high water levels in the region.

The Quebec public utility alerted Nunavik organizations this past spring that it may need to do a controlled release of water this summer from its largest reservoir in the James Bay hydroelectric project, located southwest of Kuujjuaq.

Hydro-Québec said the reservoir was at 86 per cent capacity last week when officials made the decision to release an additional 750 cubic metres of water per second from its Duplanter spillway starting on Friday, July 20.

The controlled release is expected to continue until the end of August, said Hydro-Québec spokesperson Francis Labbé.

“We have to prepare for an important fall season in terms of rain,” said Labbé in an email to Nunatsiaq News.

“We do not know if rain will be as [significant], but we must prepare as if it is going to be the rainiest fall in the last 20 years. We might open for a shorter period if weather continues to be dry.”

Under the James Bay and Northern Quebec Agreement, Hydro-Québec is required to give 30 days’ notice before a controlled release.

But since plans for a potential dam release were made public in April, Kuujjuaq residents have raised concerns over the potential impact higher water levels could have on wildlife and harvesting in the region.

The surplus water would be released into the Caniapiscau River, a tributary of the Koksoak River, which skirts the community of Kuujjuaq and flows through to Ungava Bay.

At a release rate of 750 cubic metres per second, Hydro-Québec estimates the water levels could rise up to 10 cm around Kuujjuaq and 30 cm in the Koksoak estuary.

But Hydro-Québec has also said its goal is to bring down the amount of water released to 450 cubic metres per second shortly after the spillway is opened.

Labbé also said HQ officials will fly over the region to monitor the spill, and they intend to invite Inuit from Kuujjuaq to take part in those flights.

Nunavimmiut haven’t forgotten a controlled release from the same reservoir more than 30 years ago, in 1984, when the power corporation released an additional 1,500 cubic metres per second over the summer months.

In October of that same year, an estimated 9,000 caribou drowned during their fall migration in the region, just southwest of Kuujjuaq.

Hydro-Québec denied that the controlled water release was the issue, saying the tributaries in the region were already swollen from heavy rains that year.