FARGO, N.D. — Weary residents welcomed the Red River’s further retreat today but faced an approaching snowstorm expected to kick up wind-whipped waves that could threaten the sandbag levees they built to protect their city from a major flood.

Engineers weren’t worried about the storm’s snow because it’s unlikely to melt soon. They were concerned, however, that crashing waves could weaken the dikes.

The higher the wind speed, the higher the threat, said Jeff DeZellar, a spokesman for the U.S. Army Corps of Engineers.

“The forecast that we saw was 25 mph or more, and certainly that’s enough wind to create some wave action on the river,” he said today.

National Guard members placed sheets of plastic over the levees to help them hold up against high waves. “It’s important to get as much work done as we can before the storm comes,” DeZellar said.

The week began today with much of Fargo shut down, school called off for the entire week and many businesses keeping their doors closed because of the Red River, which was ebbing after its steady, threatening rise last week. With the storm expected to arrive from the west during the afternoon and last through Tuesday evening, many people just wanted things to get back to normal.

“I just think everyone is stir-crazy now,” said resident Kathy Roscoe.

People were especially anxious as it gets tougher to pay the bills after a week of not drawing paychecks. “I’m not sure how I’m going to do it right now,” 24-year-old hair stylist Amber Fischer said of her paycheck-to-paycheck existence.

By midday today, the Red had fallen to just above 39 feet — down more than a foot from its nearly 41-foot crest on Saturday. City officials said they wouldn’t breathe easy until it falls to 37 feet or lower, expected by Saturday.

“The difficulty with an epic flood is nobody has been through it before,” said city commissioner Tim Mahoney. “You can’t ask someone, ‘Hey, what’s going to happen next?’”

It will be more waiting to see if the levees — quickly constructed last week by Fargo’s men, women and children — can hold firm.

Fargo officials warned people to stay away from the dangerous river. The Coast Guard caught a man paddling a canoe who apparently jumped a levee to get into the water, and authorities threatened to arrest anyone who commits such a crime.

Police also said a 49-year-old woman was arrested on suspicion of drunken driving after she attempted to drive up a clay levee near the flooded river. Capt. Tod Dahle said the woman was very close to going into the water.

The flood was caused by an enormous winter snowfall that melted and combined with more precipitation to send the river to record levels. The river flows from south to north through the tabletop terrain of North Dakota, providing few opportunities to drain.

Snow was moving toward Fargo from the south-central part of the state, where 14 inches had fallen at Bismarck, where melting snow and a Missouri River ice jam caused major flooding last week. Residents had been told to keep their sandbags handy as a precaution.

The river briefly breached a levee Sunday, causing considerable damage at a school campus before officials quickly pumped out most of the water.

While officials say they have limited the damage to a small number of homes within Fargo’s city limits, several outlying rural areas have seen significant flooding. Cass County sheriff’s deputies toured some of these areas Sunday in giant National Guard vehicles, offering assistance to stranded residents.

They encountered a woman whose prescription drugs were about to run out, people who trudged out of their homes in waders and a couple who gladly got a lift out of the neighborhood on the Guard truck. All the while, huge sheets of ice floated over people’s yards and lawn furniture and children’s toys could be seen stacked up behind sandbag lines.

Public works officials were closely watching to make sure water and sewer systems remained safe. Fargo’s water and sewer plants are right next to the river, and are protected by a secondary dike system.

“If we lose water and sewer, the city is uninhabitable,” said Fargo City Administrator Pat Zavoral.

Moorhead, a city of 30,000 directly across the river in Minnesota, also was fighting to hold back the river. Moorhead Mayor Mark Voxland said he was concerned but still optimistic about how long his city’s dike could last against the pressure of the river water.

Flooding statewide was blamed for two deaths, in central and western North Dakota, in what health officials said were apparent heart attacks brought on by flood-prevention exertion.