04/25/2019 20:29 EDT | Updated 04/25/2019 20:32 EDT

Quebec Flooding Forces Evacuation, Officials Warn Of Hydro Dam Failure

"We are expecting more rain over the coming hours and days."

Ryan Remiorz/CP
Workers install a temporary dam to hold back floodwaters on April 25, 2019 in Laval, Que.

MONTREAL — Quebec public security officials called for the immediate evacuation of an area along the Rouge River west of Montreal on Thursday because of the risk a hydro dam could fail.

Simon Racicot, director of production and maintenance with Hydro-Quebec, told reporters the dam at Chute Bell was built to withstand what he called a millennial flood.

"That means a flood that happens every 1,000 years," Racicot said. Hydro workers discovered earlier in the day the millennial level of water had been reached.

"We are confident that the structure is solid," Racicot said. "But the protocols force us to warn people of the danger. We are entering into an unknown zone right now — completely unknown."

Ryan Remiorz/CP
Residents wade through a flooded street on April 25, 2019 in Laval, Que.

The largely rural section of river affected is in Quebec's Lower Laurentians region, about 140 kilometres west of Montreal, stretching about 18 kilometres south to the Ottawa River.

Public Security Minister Genevieve Guilbault told reporters Thursday evening the province's hydro utility is confident the dam can hold back its current water reservoir and is structurally sound.

"But we are expecting more rain over the coming hours and days, so the water levels of the Rouge River can rise," she said in Montreal.

Guilbault said there are 23 residences and 38 cottages in the evacuation zone along the river. Quebec provincial police tweeted they were helping about 250 people get clear of the affected area as a preventive measure.

Ryan Remiorz/CP
Marc-Andre Forget keeps an eye on the floodwaters in front of his home April 25, 2019 in Laval, Que.

Hydro-Quebec said through social media that if the dam breaks, the water flow would have minimal impact on locations downstream once it joined with the Ottawa River.

The dam failure alert was to be maintained until 11:45 p.m. Thursday, according to the Quebec public security website.

Quebec Premier Francois Legault tweeted that those at risk had been advised and provincial authorities are keeping close tabs on the situation.

The warning comes as many parts of Quebec have been hit by flooding. Officials say the flood risk remains high because of a combination of precipitation in the forecast and melting snow to the north.

Earlier on Thursday, Guilbault toured the Lachute area, northwest of Montreal, where flood waters on the Riviere du Nord have risen in recent days.

Ryan Remiorz/CP
A goose makes its way through floodwaters on April 24, 2019 in Laval, Que.

She said she was impressed with the level of preparation in smaller communities and was satisfied that the number of people on the ground working on flood relief — which includes nearly 1,000 Canadian soldiers — was sufficient.

Guilbault added she wouldn't hesitate to ask for more help if necessary.

Quebec public security officials said more than 2,500 homes were flooded and more than 2,100 were isolated Thursday, meaning they were considered cut off due to washed out roads or landslides.

Authorities also warned specifically against landslides reported in various parts of the province.

One person has died since widespread flooding began in the province.

In Montreal, officials raised the security level and increased the number of teams on the ground amid fears flooding could get worse in the coming days but stressed the situation was under control.

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"You're going to see more firefighters, you're going to see more police officers and more municipal workers to help for floods that could come this weekend," said Martin Guilbault, operations chief of the Montreal fire department.

Mayor Valerie Plante warned that anyone who was flooded in 2017 should prepare their homes for more flooding — and possible evacuation — if they haven't done so.

"The threat is actually very concrete and direct and this is the message we want to send the entire population," she said.

Environment Canada issued a rainfall warning for Montreal with 30 to 50 millimetres expected Friday and Saturday.

Rain is expected to begin southern Quebec midday Friday and intensify overnight, spreading eastward.

In Ottawa, Mayor Jim Watson declared a state of emergency Thursday afternoon, calling in the Canadian Forces to help with flood protection.

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