Massive ice jams bottlenecking Manitoba's Red River have prompted evacuations Wednesday in communities north of Winnipeg.

Flooding is causing nightmares in and around St. Andrews and Lockport, and it has prompted the municipality of St. Clements to declare a state of emergency. At least four families have left their homes as of Wednesday evening.

Overland flooding is closing more roads and highways everyday. Roads in St. Andrews, which drivers were navigating just a day ago, were completely washed out on Wednesday as crews closed them to pump out the rising water.

Huge shards of ice on the Red River jammed up near Lockport, as water has been flooding parts of St. Andrews since Wednesday morning.

Meanwhile, a winter storm is bearing down on Manitoba, causing more concern for already worried residents.

In the town of Landmark, councilor Robert Koop told CTV Winnipeg that 50 homes are already in danger of being flooded, and the added precipitation could make things worse.

The storm is causing other problems as well, making it difficult for workers tasked with unblocking the hundreds of culverts in the town that need to be re-opened.

In the municipality of Ritchot, Mayor Bob Stefaniuk said the flood forecast anticipated a "certain amount of precipitation" -- so the expected 25 centimetres of snow has already largely been accounted for in the town's preparations.

Dykes were built in Ritchot following the flood of 1997, said Stefaniuk -- but the concern now is inland flooding. Up to 1,000 homes could be at risk, and many roads are already underwater.

"We're prepared as much as we can be," Stefaniuk told CTV Winnipeg.

Meanwhile, Manitoba's chief officer of health is warning residents who use well water to boil it before using it.

Well-water systems can become contaminated with bacteria when it floods. Water should be brought to a rolling boil for one minute before drinking or making ice, making drinks such as infant formula, preparing food and brushing your teeth.

South of the border

Meanwhile, U.S. President Barack Obama has declared North Dakota a federal disaster area as rising water levels along the Red River, which flows northward into Manitoba, threaten residents.

In Fargo, N.D., and Moorhead, Minn., the Red River's crest was recorded at 10.3 metres early Wednesday. It is projected to reach 12.5 metres by Friday evening.

On Wednesday, officials called for even more sandbagging volunteers as hundreds of people worked to construct a 13-metre emergency dike to protect downtown Fargo.

However, the predicted crest is still expected to threaten several neighbourhoods and hundreds of homes in low-level areas.

"We don't see any fear," Fargo Mayor Dennis Walaker said. "We just see people working very hard."

The crest of the river is expected to cross into Manitoba in a few weeks.

In the province, communities preparing for flood waters are already dealing with melting ice, and Dominion City has declared a state of emergency.

Residents say ice is thawing during the day and freezing at night, sealing sewer drains and preventing water from draining.

Roughly 200 culverts in Dominion City were frozen shut, but workers are now trying to break through the ice.

Winnipeg is having a similar problem. A city official told The Canadian Press there have been 2,500 complaints about water-clogged streets and at least 67 basements were flooded.

Meanwhile, in the nearby Roseau River First Nation, residents are sandbagging their homes and preparing to move to a safer location. It's a yearly activity as the Red River threatens to spill over.

Missouri River

In N.D., residents along parts of the Missouri River have also been told to evacuate because of rising water levels.

Officials are discussing using dynamite to blast an ice jam to ease flooding around the town of Bismarck.

On Wednesday, North Dakota Gov. John Hoeven said the river appeared to be holding steady.

Bismarck Mayor John Warford said the river had not risen since midnight.

Earlier, Sen. Kent Conrad, D-N.D., called Bismarck "the most urgent threat" in the state because of ice jams located north and south of town.

The forecast is also calling for heavy snow, which is intensifying the threat.

Meanwhile, authorities transferred 146 inmates from the Missouri River Correctional Center because of the flood threat.

As a federal disaster area, the federal government will pay for 75 per cent of state and local government costs to deal with the flooding.

With reports from CTV Winnipeg and files from The Associated Press