Thousands of Canadians across the country spent the weekend in a desperate struggle with rising floodwaters caused by unusually persistent rainfall.

On Sunday, Montreal became the latest city in Quebec to declare a state of emergency after three dikes gave way in the Pierrefonds-Roxboro borough, in the north end of the city by the Rivieres des Prairies. Montreal Mayor Denis Coderre said homes have been evacuated in that borough as well as on two nearby islands.

He said officials were prepared to remove people from their homes if they refused to evacuate.

"I understand that morally or psychologically, physically, mentally, people are very, very tired. We're talking 24 hours in a row of people helping each other," Coderre told reporters. "But sometimes we need to protect people from themselves."

Nearly 1,900 homes have been flooded in 126 municipalities in the province.

Public Safety Minister Ralph Goodale said that the military response to flooding in Quebec is likely to balloon.

"At the moment, since yesterday, there are 450 Canadian forces personnel on the ground in various locations across Quebec," Goodale told CTV's "Question Period" on Sunday.

"The expectation is that by the end of the day today that number will likely have tripled as the Canadian forces add more and more resources to assist the civilian authority in Quebec."

Coderre said earlier Sunday the city has 30 Canadian Forces personnel helping firefighters and other emergency responders with the flood response.

"We have over 100 firemen who are working 24 hours a day, visiting door to door and making some evacuations," he said.

West of Montreal, the small town of Rigaud issued a mandatory evacuation order Sunday and a state of emergency has been in place for several days.

Mayor Hans Gruenwald Jr. told reporters at a town hall that firefighters will be going door to door to make sure people in the affected areas leave their homes.

"We will follow the fire department and actually remove the people if need be," Gruenwald said. "Because it is either that or services will be stuck to remove those people under a state of emergency at two o'clock in the morning on a stretcher -- I'm sorry but we are not going to go there."

Quebec Premier Philippe Couillard visited the town Saturday and urged people to heed authorities if they recommend they leave their homes.

In Gatineau, Que., near the border with Ontario, 380 residences were evacuated and officials want to evacuate another 900 homes Sunday.

Meanwhile, Goodale said no other province has so far requested military help, but forces personnel, including reserves, are on stand-by across the country.

The situation in Ontario seems to be "generally stabilizing," although there are many unstable local circumstances, he said.

In the eastern Ontario village of Cumberland, Christina Hajjar said she and her family likely won't be returning to live in their two homes that were destroyed by the flood.

"They are quite old," she said Sunday. "I don't think they'll be salvageable after sitting in a foot of water for goodness knows how long."

For the moment Hajjar is staying in an inn in the nearby town of Clarence-Rockland, where she said she's receiving a lot of community support.

"They were sending food, they were sending volunteers, they were sending sandbags even when they shouldn't have been, to try and get our neighbourhood safe," she said, adding that a woman offered to do laundry for her, and a company delivered food for her to eat.

"At this point, we just really are hoping that the faith we're putting in the government is put in the right place and they'll come through for us in the end."

Rob Kuhn, an Environment Canada meteorologist based in Toronto, said Sunday that eastern Ontario saw the most rainfall in the province. He added that upward of 80 millimetres of rain fell between Friday and Sunday morning in the Trenton area.

In Atlantic Canada, some parts of New Brunswick recorded more than 150 millimetres of rain after a nearly 36 hour non-stop downpour.

A weather station northeast of Saint John, N.B., measured 155 millimetres of precipitation from late Friday to early Sunday, Environment Canada meteorologist Stephen Fougere said Sunday, adding that surrounding areas had up to 125 millimetres.

While the deluge has tapered off in the province, New Brunswick's St. John River is spilling its banks, prompting several road closures.

"It's above flood stage in several areas from Fredericton down south," said Robert Duguay, a spokesman with the province's emergency measures organization. "Water levels are going to stay high probably for the rest of the week."

He said the situation is under control with only minor flooding.

Still, Duguay said a shift in weather patterns could quickly change the situation. Waterways remain extremely precarious, he said, and people who get too close are at risk of being swept away by fast-moving water.

In British Columbia, the worst may be over after floods and mudslides wreaked havoc in the Interior over the weekend.

B.C.'s River Forecast Centre says water levels have been receding throughout western portions of affected areas, including the south and central Okanagan and the Kootenay and Shuswap regions. The forecast centre is maintaining a flood watch for Salmon Creek and a high streamflow advisory across the province's southeast.

Two people remain missing, including a 76-year-old man whose home north of Salmon Arm was engulfed in a mudslide on Saturday, and a fire chief believed to have been swept away by a swollen waterway west of Kamloops.

With files by Nicole Thompson in Toronto, Brett Bundale in Halifax, and Geordon Omand in Vancouver.