A literal and figurative “code red” alert has been issued for the Red River Valley as melting snow and spring rains could combine to create the highest river levels since the last “flood of the century” on this northward-flowing river in 1997. By Monday morning the Red River had risen to 23 feet, and it’s now expected to peak at 40.1 feet Friday morning in the Fargo-Moorhead area. That would top 1997’s record crest of 39.6 feet.

The weapon of choice to fight the rising river? Sandbags. More than 2 million of them if possible. Officials in Fargo, N.D., and Moorhead, Minn. — two cities thought especially vulnerable this year — have put out an urgent appeal for volunteers to fill and stack the burlap bulwarks.

Fargo city officials believe they will now need up to 2 million sandbags, but they had only filled 560,000 by Monday morning. The city just added a third “spider” machine, which can quickly get the job done. But according to Mayor Dennis Wallacher, unless up to 1,000 people volunteer on a continuous basis for filling and stacking the job may not get done. City officials are especially appealing to night-owl volunteers. To keep sandbagging going around the clock, they’re hoping for 150 volunteers or more for late-night and overnight shifts.

The sandbagging procedures are different across the river in Moorhead, but not the need, according to City Councilman Mark Hintermeyer. “We are taking in as many volunteers to make sure we can get as much done today as we can,” Hintermeyer said Monday morning. He added that volunteers will be needed for days to come.

Of course nature knows no state boundaries, so Minnesotans and North Dakotans up and down the Red River will have their own red alerts, especially as the floodwaters head north to Grand Forks, N.D., and East Grand Forks, Minn., after Fargo-Moorhead crests. Weather experts are particularly concerned because the ground is impermeable to water; a deep freeze that followed a rainy fall last year turned sodden ground solid. Water runs off it the way it would a concrete driveway.

This year’s flood threat is just the latest example of how nature routinely makes living in the Upper Midwest a special challenge. Luckily there’s also a can-do spirit that comes with living here, and a powerful sense of community unites us in times of crisis. Minnesotans rallied to help flood-stricken Grand Forks in 1997. Hundreds bolstered the recovery effort in southeastern Minnesota in 2007. And volunteers drove hundreds of miles last year to lend a hand when a raging river laid waste to Cedar Rapids, Iowa.

It’s time once again to come to the aid of our neighbors. History suggests Minnesotans will not disappoint.