(CNN) -- An inch of rain doesn't sound like a lot. But in parts of the flooded Midwest, it's enough to make a bad situation worse.
In Illinois on Tuesday, residents braced for the extra inch, which will delay any reduction in floodwaters that have ravaged dozens of counties, forcing thousands of residents from their homes.
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, according to the National Weather Service.
Along the mighty Mississippi, flood watches stretch as far south as Louisiana. Although flooding is expected all 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, as the overflowing Red River flows toward Fargo.
The city has begun a three-day push to truck sandbags into low-lying areas. Police cars are escorting the semi-trailer trucks as they head to the locations, CNN affiliate KVLY reported.
Conditions could get worse: Additional rain could speed up the melting of snow, making the river rise even faster.
Starlynn Winchell stared Tuesday as the Illinois River rushed up against her home in Spring Bay, Illinois. "The more I see the water come up, the more I'll cry," she said.
At least six rivers in northern Illinois have surged to record levels in recent days after the area was deluged with 5 inches of rain. Flooding in Illinois alone has displaced thousands and prompted Gov. Pat Quinn to declare 44 counties as disaster areas.
In Peoria, residents may have narrowly missed a crisis. The Illinois River is forecast to crest Tuesday afternoon at 29.4 feet, a record height. At 30 feet, the water would have topped a levee at a sewage treatment plant -- sending raw sewage spilling into the river.
The good news is the flooding won't be as bad because of last year's drought.
"Experts told us the drought might have helped us a little bit," said Patti Thompson, a spokeswoman with the Illinois Emergency Management Agency. "We did have so much more capacity for the water to be absorbed into the ground."
Thompson said the state was in variety of stages of dealing with the high water. Some counties were seeing water starting to recede and could start cleanup, while others were working feverishly to strengthen protection measures.
Those areas expect to see rising river levels for the next several days, she said.
Missouri Gov. Jay Nixon declared a state of emergency there 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.
Winchell, the Spring Bay resident, said her northern Illinois town of fewer than 500 has been devastated.
The deluge in her trailer community began Sunday, she said, when floodwaters submerged her home and about 40 others.
By Monday, dark, murky water had risen to some homes' doorsteps. Flooding has cut Winchell off from access to her home.
"Yesterday, I cried all day," she said.
Brad Lohman, who owns a bar in the town, was also hit hard.
"It's kind of emotional to see this situation, and it's a bad deal," he said, looking at the waters that rose close to window level.
Lohman worked at the bar when he was a teenager and eventually bought it. But this flood may be the end. He doubts he can reopen.
"I think it's going be a total loss," he said, "I really do."
The rain and flooding caused three deaths last week and a fourth Sunday, local authorities and news media reported.
A woman in De Soto, Missouri, drowned last week after her vehicle washed off a road, CNN affiliate 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, Hamilton County Sheriff's Office said.
CNN's Jim Spellman contributed to this report.