Several rivers and lakes had reached near 50-year peak levels in Quebec province after heavy rains.
Floodwaters began to recede after severe flooding in eastern Canada that affected thousands of people, authorities said.
Quebec's Prime Minister Philippe Couillard said that the levels had begun easing off on Tuesday.
"We are now entering a period of falling water levels," he said, but warned that this did not mean flooded areas would be easily accessible again even in the coming days.
Montreal declared a 48-hour state of emergency on Sunday but has extended it to five days.
Canadian Prime Minister Justin Trudeau said the situation was serious, noting that "Quebec and Ontario have asked for military aid" and that 1,650 members of the armed forces had been deployed to the stricken areas.
"Naturally, the federal government will cover all the costs linked to this aid for Quebec and Ontario," he said.
Several rivers and lakes had reached near 50-year peak levels in Quebec province, between Gatineau in the Canadian capital region and Montreal, 200 kilometres (125 miles) downstream.
Sunday evening, a 37-year-old man and his two-year-old daughter were reported missing after their car veered into a river and was swept away.
Quebec police continued the search on Tuesday for the toddler and said her stepfather's body had been found, the first fatality in floods that have inundated the Canadian province.
TRT World spoke with journalist Sean Mallen, who has more on the story from Toronto.