A blizzard battered North Dakota on Monday, threatening to create wind-whipped waves that could lash the patchwork levee system that has shielded much of Fargo from the swollen Red River.
Engineers scrambled to shore up the dikes in hopes of averting the latest potential disaster nature has inflicted on this beleaguered city.
The winter storm was expected to bring up to a foot of snow and 30 mph winds that could weaken the levees with big waves. Officials acknowledged that no one knows whether the levees will withstand the punishment.
"The difficulty with an epic flood is nobody has been through it before," city Commissioner Tim Mahoney said. "You can't ask someone, 'Hey, what's going to happen next?"'
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The Red River dropped to 38.80 feet Monday, nearly 2 feet below its peak but nearly 21 feet above flood stage. City officials have said they would breathe easier when the river falls to 36 or 37 feet or lower.
Authorities were not especially worried about the snowfall because flood levels will have dropped by the time it melts. But forecasters have warned all along that the river could still rise again. They believe the river could drop 2 more feet in the coming days before inching upward again.
Some residents in the Fargo area said that Monday's snowstorm amounted to a kick in the gut after a grueling week of filling sandbags and fortifying their homes against flooding, which was caused by heavier-than-average winter snows, combined with spring rains and an early freeze last fall that locked a lot of moisture into the soil.
"You kind of feel like it's a Bruce Willis film with the next challenge, next challenge, next challenge," Mahoney said.
Engineers are still worried that the levees could give way at any time, and they sent teams out to vulnerable areas Monday to strengthen the system. National Guard members placed sheets of plastic over the levees to shield them against waves.
Corps engineer Tim Bertschi said when water pressure gets strong enough, the sandbags can begin to shift, a weakness that surging water will quickly exploit.
Another potential problem is posed by large chunks of ice in the river's currents. When those chunks hit a levee, they can speed its erosion or punch holes in the plastic sheeting. Once water gets in, a levee becomes much more susceptible to failure.
"Anything you are going to build, you've got to suspect it's going to fail at one time or another," said Bill Buckler, an associate professor of geography at Youngstown State University in Ohio.
National Guardsmen Brandon Nelson and Cody Renner shuffled along a Fargo dike just south of downtown on Monday, headed toward their assignment for the day: Monitor a small crack in an earthen dike. Should the crack in the dike go unmonitored and widen significantly, it could put the heart of Fargo at risk of flooding.
So they checked the crack every 15 minutes, measuring its depth and prepared to notify the Army Corps of Engineers if it grew. Corps officials stood at the ready in a nearby parking lot.
As the city waited for the storm, schools and many businesses were closed for a second week, meaning thousands of people are not drawing paychecks and are eager to get back to work.
The blizzard "just makes everything miserable. People here are expecting anything now," said Dick Schafer, a high school counselor who was using a shovel to break ice off his driveway as heavy, wet flakes fell.
Fargo's massive sandbagging began winding down after an around-the-clock volunteer effort. Fargo filled 3.5 million sandbags, and has an inventory of 450,000.
Officials in Fargo and Moorhead say they have limited the damage to a small number of homes within Fargo's city limits, but they have had to rescue about 300 people by boat, and several outlying rural areas have seen significant flooding.
Authorities also 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 vowed to arrest anyone who took similar risks.
Flooding statewide was blamed for two deaths in what health officials said were apparent heart attacks brought on by exertion.