The Missouri and Mississippi are most worried about.
After a year that has seen some of the worst flooding ever in parts of the Midwest, concern is already rising that the spring of 2020 may bring more high water to places that still haven't fully recovered.
Flooding ravaged much of the Missouri and Mississippi River basins and their tributaries earlier this year, reaching record levels and overwhelming levees in many places. Eight months later, parts of the Missouri River are slightly above flood stage at a time of the year when river levels traditionally run low.
Conditions are only slightly better on the Mississippi River, which is just a couple of feet below flood stage at several towns from Burlington, Iowa, south to near St. Louis.
High river levels aren't the only worry. National Weather Service hydrologist Mark Fuchs cited two other factors that have him concerned: Soil is extremely saturated in northern states like Wisconsin, Minnesota and the Dakotas, and the long-range forecast offers a strong possibility of a wetter-than-normal winter.
"We're worried about rivers in general, primarily the Missouri and Mississippi for the spring," Fuchs, of the weather service's suburban St. Louis office, said. "We'll see how the winter plays out."
Areas along the Missouri River in parts of Nebraska, Kansas, Iowa and Missouri were particularly ravaged in the early spring, damaging hundreds of homes and businesses.
In Buchanan County, Missouri, some county roads were damaged on three separate occasions as floodwaters would rise, fall, and rise again. Emergency Management Director Bill Brinton said those roads have been fixed to the point of being passable but with the strong prospect of more potentially severe flooding next spring, full repairs will have to wait.
Levees that were overtopped and breached in spring and summer flooding also remain unrepaired, meaning that the next big flood could get back into the same homes damaged months ago.
"It's kind of scary for the spring," Brinton, whose county had about 150 homes damaged, said. "These people have had their lives impacted three separate times this year."
The Mississippi River reached near-record levels at several points, including the second-highest ever at St. Louis. Both the Mississippi and Missouri rivers dipped below flood stage by early fall, "then they turned around and went right back up in October with more rain in both basins," Fuchs said. "For both rivers, there really hasn't been much chance to recover."
Fuchs said soil moisture levels in many places to the north are at the 99th percentile for late fall.
"If you have rain, it's supposed to go into the ground," Fuchs said. "Well, there's just not room in the soil to accept rainfall or snowmelt."
Adding to the worry is the weather service's December-February forecast which shows a significant chance of above-normal precipitation in the upper Midwestern states that feed water into the Missouri and Mississippi rivers.
For now, all river communities can do is wait. Brinton said the holes in Buchanan County's levees are too big and plentiful to sandbag.
"I just don't see how it's not going to be a problem in the spring," Brinton said.