A massive blizzard bore down on flood-ravaged North Dakota Monday as officials struggled to shore-up levees against potential erosion from high, powerful waves and swift moving waters.

The storm comes as the weary city of Fargo remains on high alert against further breaches to its 48 miles (77 kilometers) of protective dikes and levees as the Red River is forecast to remain near record highs for days.

The 14 inches (36 centimeters) of snow predicted to strike the area was not expected to worsen the floods as it was not expected to melt until after the river levels fall significantly.

But strong winds will whip up waves as high as two feet, which will batter and possibly wash over the city's defenses, the national weather service predicted.

Response times were also going to be slowed by the snow-clogged streets and officials said renewed vigilance was needed to patrol defenses during the storm.

"We don't want to lose the fight at this point," said Deputy Mayor Tim Mahoney. "We could have a flood in areas if we don't watch our dikes."

A series of contingency dikes should protect most neighborhoods from serious damage, officials said, noting that only five homes have been lost so far within the city limits.

Scores more, however, have been inundated in rural areas and across the river in neighboring Moorhead, Minnesota where water levels reached as high as the second story in some riverside homes.

Regular boat patrols to check on people who refused to leave their homes so they could monitor their pumps and repair leaks in their dikes were to be suspended as soon as the storm hit.

The Cass county sheriff urged people to prepare for a "wicked storm."

"If you need to get out, you need to get out now," Paul Laney said at a morning press conference.

"In North Dakota we're pretty used to rough winters but when you're trapped in a home surrounded by floodwaters, you need to really assess your situation and decide if you want to be there."

Thousands of people fled their homes last week as this flat prairie state was blanketed with snow and floods that were nine miles (14.5 kilometers) across in some points.

The Red River reached a high of 40.8 feet (12.4 meters) early Saturday in Fargo -- breaking the previous record of 40.1 feet (12.2 meters) in 1897 -- and only inches below the top of the city's highest levees.

By Monday morning it had fallen to 39.2 feet (11.9 meters) but officials said the city would not be clear from danger until river levels dropped by three more feet.

The river's flood stage in Fargo is 18 feet.

"A lot of people want to do the dance on the dike but we've got a long way to go," said Greg Gust, a meteorologist with the National Weather Service who predicted that the river could remain above flood stage for a month.

"Every day the water's up against there they're going to be working to reinforce those dikes because they don't want them to fail," he told AFP.

"It's (a question of) how many fingers I need to plug those holes."

City officials warned it will likely take two months and millions of dollars to clean up the mess made by both the floods and the dikes and levees.

"It takes time you can't just turn on a light switch and everything comes back to the way it was a week ago," Mahoney said.

Both Grand Forks, North Dakota and Winnipeg, across the border in Canada, have flood diversion systems that should protect them from the forecasted crests as the river makes its way slowly northward.

People were also reminded to stay off the levees and river.

A drunk woman was arrested early Monday for trying to drive her van over a four-foot high clay dike. She came dangerously close to spilling over into the icy waters but did not do substantial damage to the dike.

A man was also arrested for taking a canoe out on the flooded river.