City crews were set to start delivering sandbags to neighborhoods Thursday, but a looming winter storm has delayed dike construction until next week.
A winter storm is heading for the area this weekend, followed by temperatures well below freezing. Officials worry sandbags would freeze and become unusable.
Moorhead Mayor Mark Voxland said the weather will shorten the time frame for building dikes.
"Every day it just seems like we're compressing that time line," Voxland said. "So once we can get sandbags out it really is going to be critical to have volunteers out and have homeowners ready to go."
Weather conditions might not improve until the middle of next week. Voxland said he's concerned rain and snow forecast this weekend could push the river crest higher.
"It's just the angst of when will the river come up and how high will the river decide to go before it crests," he said.
The National Weather Service says there's a 50-50 chance the Red River could approach record levels in Fargo-Moorhead.
Fargo and Moorhead city officials have about 4 million filled sandbags in warehouses, ready to be delivered to neighborhoods.