Manitoba officials partially activated the province's floodway Wednesday, after water levels rose to more than six metres in some parts.
Sirens blasted to let residents know that water would start flowing through the man-made waterway that diverts part of the river's flow around the city.
The Red River is covered in a layer of ice, and forecasters are unsure how high water levels will rise.
Premier Gary Doer, along with other provincial officials, took a tour of the flood zone Wednesday morning, to survey in advance of any flooding. Doer later said he had never seen so much ice.
"I won't feel comfortable until the ice has moved completely out of Winnipeg, completely out of the floodway and completely through Selkirk without flooding people," he said.
More than two dozen homes north of Winnipeg have already been damaged because of water that rose due to ice jams.
On Wednesday morning, flood waters were already covering a lot of farmland in the southern part of the province, particularly in the small town of St. Jean Baptiste, Man., near the U.S. border.
But officials in Winnipeg and at the provincial levels have been doing all they can to mitigate any flooding problems: Aside from the opening of the floodway, selected roadways have been closed, volunteers have been mobilized and the City of Winnipeg prepared a half-million sandbags in advance of any flooding.
While this year's flood won't cause anywhere near the damage that the so-called flood of the century caused in 1997, provincial Emergency Measures Minister Steve Ashton says Manitobans still need to be prepared.
"Clearly there is going to be some significant flooding no matter what happens," Ashton said Tuesday.
"We're bracing ourselves but this is Manitoba. We're ready. We will be adapting to circumstances as they develop as quickly as possible."
With a report from CTV Winnipeg and files from The Canadian Press