(CNN) It's a tense waiting game for people facing flood threats from swollen rivers and creeks in parts of Iowa and Wisconsin.
Flooding already claimed two lives this week in western Wisconsin's Vernon County. One man was killed Thursday after a mudslide destroyed his home, according to CNN affiliate WEAU-TV. A second man died Thursday while trying to drive through floodwaters near his home, the station reported.
In Iowa, people are waiting for the Cedar River to breach its banks. In Cedar Rapids, the latest projections show the river will crest at 24 feet Monday, according to the city's website. City officials raced Saturday to get the area and citizens ready.
At a news conference Saturday morning, Cedar Rapids Fire Chief Mark English urged people in hundreds of homes and businesses near the Cedar River to plan to evacuate by 8 p.m. Sunday in preparation for the expected flooding. The evacuation is not mandatory, but it is highly recommended, English said.
Mayor Ron Corbett said evacuated people should expect the downtown area to be closed off until October 1 following the evacuation.
Police Chief Wayne Jerman said a curfew will go into effect at 8 p.m. Sunday for evacuated and flood-affected areas and will go on until 7 a.m. Monday. The curfew is expected to be in effect every evening until the flooding subsides.
Officials begged people to stay out of downtown unless they had essential business there so the city can keep streets cleared for flood response crews. The city of Cedar Rapids also tweeted the plea.
Cedar Rapids City Manager Jeff Pomeranz thanked volunteers who answered the city's call for help Friday and Saturday to put together sandbags to hold back the Cedar River's raging waters.
"This is a situation no entity can handle alone. Our volunteers have been absolutely phenomenal," he said.
Cedar Rapids police tweeted a video of volunteers who gave up their Saturday morning to help out.
Volunteers also helped clear out the first floor of a local elementary school. Cedar Rapids Schools tweeted photos of people working Friday at Taylor Elementary School.
Other cities and towns in Iowa are also facing serious flooding, including Waterloo and Charles City, CNN affiliate KCRG-TV reported.
CNN affiliate KGAN-TV tweeted photos from cities already seeing flooding.
Govs. Terry Branstad of Iowa and Scott Walker of Wisconsin each declared disaster emergencies for 13 counties, freeing up state resources to respond to the flooding.
Both governors were expected to tour affected cities in their state Saturday.
Branstad tweeted pictures from his stop in Clarksville, where people are already seeing damage.
More than 180,000 sandbags, 4,300 linear feet of flood barriers and 27 water pumps have been delivered to the impacted areas by the Iowa Department of Homeland Security and Emergency Management, Brandstad's office said.
Heavy rain this week in eastern Iowa and southern Wisconsin is behind the flood threat in those areas. Some cities saw as much as 10 inches of rain between Tuesday and Thursday, CNN meteorologist Allison Chinchar said Saturday afternoon.
More rain is expected in the region over the next 36 hours, according to Chinchar. She said people near the Iowa-Wisconsin border can expect to see about half an inch of rainfall.
"It may not sound like a lot, but on top of the rain that fell during the week, it adds up," she said.