Premier Greg Selinger said Friday that calling in the army will help protect about 200 rural homes from a flood that could topple records set in 2011.
Selinger said he spoke to Prime Minister Stephen Harper to brief him on the situation and decided the province needs military help to shore up dikes along the swollen Assiniboine River.
The military will help fill 500,000 sandbags needed to protect vulnerable properties just west of Winnipeg, he said. The province already has 2 million sandbags in stock.
"Additional assistance is required for our flood preparations," Selinger said. "These measures will allow our officials to take the necessary actions to help protect the safety, health and welfare of Manitobans."
People living along the river have been told the water level could swell half a metre above where it was three years ago.
The 2011 flood was one of Manitoba's worst as army reservists scrambled to help shore up weakened dikes and sandbag homes along the river.
Officials operated the Portage Diversion, a channel that funnels water from the Assiniboine River into Lake Manitoba, over its designed capacity. The river crested for months, weakening dikes and pushing water levels up on Lake Manitoba and Lake Winnipeg.
The province is forecasting similar flows this year when the crest arrives from Saskatchewan as early as this weekend. The crest is expected to move through relatively quickly, in a matter of weeks as opposed to months.
"The good news is people know what they're doing," Selinger said.
"They've been through it unfortunately before, three years ago. We're all seized of the need to work together and we will be working very closely together to manage this as we go forward."
Robert Poirier, chief administrative officer of St. Francois Xavier municipality west of Winnipeg, said people who live along the river were told after the 2011 flood to put in permanent flood protection.
But he said he doesn't know how many people took that advice. Unlike 2011, Poirier said they haven't been sandbagging for months and aren't prepared for a flood-fight this late in the year.
"There is a bit of anger, a lot of resignation," Poirier said.
"In 2011, the province had been busily making sandbags for four months, as had we. We consumed something on the order of more than 200,000 sandbags over the course of a week or two."
The situation is changing rapidly.
The city of Brandon revised its flood forecast overnight. The crest was intially expected to hit the city late next week but official now say it could arrive as early as Sunday. However, the city downgraded the size of the crest in its latest update by up to one-third of a metre.
Officials say people living north and south of the Assiniboine River will receive pre-evacuation notices over the weekend and dikes will be monitored regularly.
Torrential rain and flash floods last weekend prompted more than 100 communities in Saskatchewan and Manitoba to declare a state of emergency. About 300 people in Saskatchewan and 565 people in Manitoba have had to leave their homes because of overland flooding.
The situation appeared to be improving in Saskatchewan Thursday. Water started to recede in communities and move through the river systems toward Manitoba.
The Saskatchewan government is opening a flood recovery centre in Melville to help those affected residents.
Farmers in both provinces have borne the brunt as overland flooding turned fields into lakes. Officials say it will be a while before they can assess the damage to crops, homes and roads.