A state of emergency is in place on the island of Montreal due to the threat of flooding in several areas.

Mayor Valérie Plante made that announcement in the borough hardest hit by flooding, Pierrefonds–Roxboro in Montreal's West Island, Friday afternoon.

The state of emergency gives the city the power to seize land, to make evacuations mandatory and to put in place other flood prevention measures.

It covers the City of Montreal and demerged municipalities on the island.

"It's never our first choice to ask people to leave their homes," said Plante at a news briefing announcing the state of emergency.

"People need to understand that this is serious. This is dangerous."

So far, a dozen homes in the Pierrefonds district have been identified as needing to be evacuated immediately.

Montreal Mayor Valérie Plante, centre, declares a state of emergency. (CBC)

Municipal officials said firefighters have been coding homes with yellow or red stickers: yellow means a home is at risk, and red means a mandatory evacuation.

Eleven of the 12 homes identified with red stickers have been evacuated.

But more evacuations may be needed this weekend, said the head of the Montreal Fire Service, Bruno Lachance, who is co-ordinating all flood relief efforts now that the state of emergency has been declared.

And here they go... <a href="https://twitter.com/hashtag/flood2019?src=hash&ref_src=twsrc%5Etfw">#flood2019</a> <a href="https://twitter.com/hashtag/Inondations2019?src=hash&ref_src=twsrc%5Etfw">#Inondations2019</a> <a href="https://t.co/pIZCs1nqHP">pic.twitter.com/pIZCs1nqHP</a> —@TurnbullJay

Lachance said that some of the dikes that have been built up with the assistance of the Armed Forces may not be able to withstand the rising water.

It's important that residents of Île-Bizard, Pierrefonds and Ahuntsic be prepared to leave their homes, Lachance said, as it's unclear which dikes will overflow.

This is the type of balloon that municipal workers will be stuffing inside a drain pipe in Pierrefonds to block the Rivières des Prairies from flooding streets. (City of Montreal)

Pierrefonds–Roxboro Mayor Jim Beis said residents were told what to do in case of an evacuation order as part of the borough's flood preparation.

"The safety of our residents is the number one priority," he said.

According to the latest numbers from Quebec's Public Security Ministry, 75 homes in Montreal have flooded.

The city last declared a state of emergency in May 2017, when the Rivière-des-Prairies caused flooding in many of the same areas now underwater.

Armed Forces personnel use sandbags to protect a house against the floodwaters in Laval, Que., on Thursday. (Ryan Remiorz/Canadian Press)

Island residents asked to leave

The City of Laval is recommending the evacuation of several areas at high risk of flooding, as floodwaters continue to rise.

The neighbouring city expects that rain in the forecast Friday night and on Saturday, mixed with melting snow, will raise water levels beyond those reached in 2017.

Residents living on Bigras, Parizeau, Verte and Roussin islands are strongly encouraged to leave their homes. The same applies to residents of Laval's main island, Île Jésus, living in areas designated Zone A.

The zones can be found on Laval's interactive map.

A man pulls a dog in a boat along a flooded street as he leaves his home in Rigaud, west of Montreal, Friday. (Graham Hughes/Canadian Press)

More rain expected

With the rainy forecast, towns all over southern Quebec are preparing for more flooding.

On the Lake of Two Mountains, communities like Pointe-Calumet — just north of Île-Bizard — are bracing for the worst.

In Rigaud, near the Quebec-Ontario border, where the Ottawa and Rigaud rivers have both overflowed their banks, fire Chief Daniel Boyer says the weekend will be a "marathon," as the Ottawa River approaches levels not seen in a century.

La digue de Pointe-Calumet va-t-elle tenir le coup? « Si elle cède on est dans la... » me dit un résident <a href="https://twitter.com/hashtag/inondations?src=hash&ref_src=twsrc%5Etfw">#inondations</a> <a href="https://t.co/MQSkD597KK">pic.twitter.com/MQSkD597KK</a> —@melissa_francoi

The town issued a mandatory evacuation order Friday morning, but officials said they would not force residents out of their homes if they refused to leave.

After enduring many days of flooding, residents trying to tough it out should "put up their hands and evacuate," Boyer said.

"I think that's the most important thing to do now."

"Some people are sure to stay, but like I said, the countdown is on," said Boyer. "Every day, morale drops, strength decreases."

"Stop fighting it. It's going to continue to rise. The flood is going to continue to rise."