Fargo is bracing for what could be one of the top five floods in its history.

The U.S. National Weather Service announced Thursday that residents living along the Red River in Fargo and Moorhead, Minn., should prepare for one of the top five worst floods in the history of their area.

The weather service released its flood outlook for the area, saying there was a 50 per cent chance the river could top 11.6 metres, that’s 6 metres higher than its flood stage.

'Then you throw rain on top of it; it's like pouring gasoline on a fire. It just would boom.'—Gregory Gust

Gregory Gust, a meteorologist with the U.S. National Weather Service, addressed the media in Fargo Thursday morning.

He said the city has received an above-normal snowfall since they released their February outlook, significantly increasing the risk of flooding in the far north and south portions of the Red River basin.

Gust said there is now a major flood risk along most of the mainstem Red River and that could translate to significant overland flooding.

"The more rapid it melts, the more quickly it would move to the river and not have a chance to sink in," said Gust.

"Then you throw rain on top of it; it's like pouring gasoline on a fire. It just would boom."

In the Red River's southern basin, Gust said there was a 10 per cent chance of having a flood of record, while in the central Red River basin, which includes Grand Forks and Oslo, there was a "somewhat increased risk" of moderate to major flooding.

"The roadways, highways — I-29 — is going to have points along it that are going to be going under water at some point," said Gust.

"Again that's big impacts into transportation corridors."

As for the northern Red River basin, Gust said there was a big snowpack and as a result some runoff concerns. Pembina had a greater than 95 per cent chance of seeing major flooding.

Both Drayton and Pembina risked flood water levels similar to those seen in 2011.

Flood mediation

The mayor of Fargo, Dennis Walaker, said the city has made a number of changes along the banks of the Red River, so fewer properties will be impacted by flooding.

That includes the 1.5 million sandbags.

"We have sandbags throughout the city in case there’s a breech, so we always want to have that excess built up," said Walaker.

"Our engineers are super-conservative. So we're not about to be caught without enough sandbags."

Ryan Viergtz works with the Fargo Fire Department. He said the city plans to begin filling sandbags next week.

"In 2009, we were over 40 feet for a crest and didn't have the permanent stuff in place that we do now," said Viergutz.

"So it's still preparation and planning stage. There isn't really any reason to get too nervous yet."

Fargo mayor wants diversion

Walaker said more work could be done to protect the town.

Walaker wants to see a diversion, similar to the Red River Diversion around Winnipeg, constructed near Fargo.

"That has to come sometime in our lifetime because until that happens, none of us are going to feel very safe in this community," said Walaker.

Walaker said a central location where the public can help with sandbag production will be running by April 3.

Gust said the community and county are currently planning and coordinating a resposne. He said the U.S. National Weather Service will continue to monitor new precipitation and prepare for the impending melt.

He said once runoff begins, the service will be able to better determine what flooding is expected.

In 2009, Fargo was devastated by major flooding, which saw homes and neighbourhoods destroyed by floodwaters. 

Manitoba will not release its flood forecast until Monday.

With files from The Associated Press