Video: More Flooding Threatens Already Drenched States in Midwest and South

A powerful spring cold snap is bringing more rain and snow to a soggy U.S. heartland Wednesday, putting more pressure on riverside communities from the upper Midwest to the Deep South.

The additional precipitation will further delay flooding recovery.

The residents of Grafton, Illinois, north of St. Louis, will see the worst of the floodwater through Friday as the Mississippi River peaks at more than 11 feet above flood stage, the National Weather Service says.

Many along the river's edge decided to evacuate, but Jerry Eller thought he would wait it out.

"I've got water coming up through cracks in the floor, so I have about 3,000 gallons an hour of pumps running down the basement keeping water out, and that seems to be keeping it down to about an inch," Eller told CNN affiliate KPLR.

Floodwater has ravaged dozens of counties in Illinois, forcing thousands of residents from their homes.

Widespread flooding

As rivers across the heartland swelled during the past two weeks, rising water was blamed for four deaths. Flooding threatens rivers in Illinois, Missouri, Iowa, Indiana, North Dakota, Mississippi and Michigan, the National Weather Service said.

The Mississippi River at St. Louis on Wednesday was above flood stage and expected to remain so through Sunday, the CNN weather team said. The Illinois River at Peoria was experiencing major flooding, which is expected to last through the weekend.

Moderate flooding through the weekend is expected north of Chicago at the Des Plaines River.

Along the Mississippi River, flood watches stretch as far south as Louisiana. Although flooding is expected along the river, experts don't expect the catastrophic levels of two years ago, when levees were breached. The flooding was so grave in 2011 that authorities purposely flooded thousands of square miles of Louisiana to spare city centers.

Residents in North Dakota are bracing for flooding, too, along the Red River in Fargo.

The city has begun a three-day push to truck sandbags into low-lying areas. Police cars are escorting the semitrailer trucks as they head to the locations, affiliate KVLY reported.

Conditions could get worse. The additional rain could speed up the melting of snow, making the river rise even faster.

Volunteer help

In Clarksville, Missouri, some 500,000 sandbags and more than 8,000 tons of sand and rock are being used to keep most of the floodwater at bay.

Mayor Jo Anne Smiley said the worst is over, but the city isn't out of the woods yet.

Volunteers from around the area played a key role in protecting the town.

"The only way this community in particular survives these kinds of events is volunteer help, because we've had more volunteers in town than we have people who live here," Smiley told affiliate KSDK. "And the people who live here are for the most part aged."

Missouri Gov. Jay Nixon declared a state of emergency last week after many areas of the state were stricken by flash flooding.

"The sustained periods of heavy rainfall (have) swollen creeks and streams and is pushing the Mississippi River over flood levels, endangering river communities," Nixon said.

Record floodwater on the Rock River is dampening the mood at Rick Wyffels' Christmas tree farm in Moline, Illinois.

"This is going to be bad," Wyffels told CNN affiliate WQAD. "This is the highest water I've ever seen down here."

The Wyffels family has farmed along the Rock River for more than 60 years. About a quarter of his crop is under water.

"We'll just have to wait and see whether these trees make it or not," he said.

Back in July, it was a different story for Wyffels as the region was locked in a drought. He lost some 900 trees in the parched soil.

Deadly consequences

The rain and flooding caused three deaths last week and a fourth Sunday, local authorities reported.

In DuPage County, Illinois, a body was found floating in Salt Creek last week, the local sheriff's office said. Authorities were working to identify it.

A woman in De Soto, Missouri, drowned last week after her vehicle washed off a road, KSDK reported.

Two fatalities were reported in Arcadia, Indiana. On Thursday, a 64-year-old man died after attempting to cross high water in his car. The water swept him off a roadway and dragged him downstream, the Hamilton County Sheriff's Office said.

CNN's Maria White, Mariano Castillo and Chad Myers contributed to this report.