The lowly sandbag has improbably — and seemingly eternally — remained the back-breaking brick of choice for anyone in a hurry to erect makeshift barriers during flood season.

But now there is growing competition.

As Fargo, N.D., confronts its third major flood in three years, local governments, businesses and residents are shifting to a number of modern alternatives to hold back the waters of the Red River.

“I’ve seen enough sandbags for a lifetime,” said Alan Kallmeyer, who enlisted dozens of friends and co-workers the last two years for a full day of this grueling masonry, filling and stacking thousands of sandbags around his riverside house.

This year, Mr. Kallmeyer bought a device, already used by several of his neighbors, that rings his house with a four-foot-tall tube of water. The device, known as an AquaDam, cost nearly $8,000. But it took just a few strain-free hours to set up and will be just as easy to take down.