Fears that a combination of heavy rain and melting snow could turn streets into rivers have area towns and residents taking what steps they can to reduce the threat of flooding.
Public works crews were busy Wednesday clearing snow and ice from storm sewer inlets in an effort to keep water flowing where it's supposed to go.
The National Weather Service issued a flood watch that started early this morning and continues through at least 6 p.m. for Cook, DuPage, Kane and Will counties.
Officials said the combination of melting snow, frozen ground and rain will boost the risk of damage, especially in flood-prone areas.
"The flooding potential is certainly there with all the water on the ground and the rain potentially coming," Warrenville City Administrator John Coakley said. "We don't have any flooding at the present time, but there's a lot of snow that's going to melt."
In Wheeling, the fire department has been assisting public works crews that have been working since Monday in anticipation of the rain and thaw.
Public Works Director Tony Stavros said workers have been moving snow away from gutter lines and clearing sewers and flood basins.
"Other than that, the rest is up to Mother Nature," Stavros said.
Colby Basham, director of Elgin's 311 Contact Center, said workers have been trying to clear as many of the city's estimated 10,000 catch basins as possible.
In many communities, officials also are asking residents for help.
Arlington Heights Public Works Director Scott Shirley encouraged residents to clear snow and slush off the storm sewers on their streets.
Storm sewer inlets generally are located in the middle of residential blocks and at intersections, officials said. They also can be found at low points of blocks.
"We have 10,000 drains in town and we can't possibly get to them all," Shirley said.
Carol Stream residents received prerecorded telephone messages asking them to dig out catch basins near their homes.
"If we work together, we're going to get a lot more of them cleared than if I just have my crews out there doing it," Carol Stream Public Works Director Phil Modaff said.
Lombard officials recommended residents shovel snow on the parkway and not into the street. And Gurnee officials are asking residents to call public works if they see 6 or more inches of standing water on their street, and they're also requesting that residents clear any sewer inlets that are blocked.
Those, of course, aren't the only concerns. Officials in many areas also are keeping a close eye on rivers and streams.
Elgin's Basham said melting ice traveling downstream along the Fox River and its tributaries might get stuck and create ice dams.
Lincolnshire is among the communities along the Des Plaines River that have victimized by flooding, sometimes severely. But Mayor Brett Blomberg said he believes the water is free of ice dams and "that's gonna help."
DuPage stormwater management officials are expecting river elevations to climb enough to warrant operation of the county's flood control facilities late this afternoon.
If forecasts are accurate, the mechanically operated facilities along Salt Creek likely will be operational for 15 to 18 hours, officials said. Operating times will be slightly longer for the facilities along the West Branch of the DuPage River.
Officials hope the gradual warm-up this week might reduce some of the flooding threat.
"This warm-up prior to the rain was advantageous in that the pavements have warmed up on the surface," Shirley said. "If the rain was coming immediately after a cold spell, it would be very different. We are preparing for the worst, but hoping for the best."
The fact that a return to cold weather is lurking right around the corner also might help.
"This isn't the massive spring thaw," Stavros said. "It's short-lived, and then temperatures are going to drop again."
While a return to cold weather might reduce the flood threat, it also could cause problems with icy roads and sidewalks. There were reports some area hospitals already were seeing an influx of fall victims caught by surprise by slippery conditions even with the higher temperatures.
For now, Modaff said his crews in Carol Stream will be focused on keeping the water flowing -- and not on salting the streets -- unless temperatures drop dramatically.
"The dilemma is if we spread salt, the ice will melt but it will freeze again overnight," he said. "So we don't plan on applying any salt, except for our major intersections and school zones, if necessary."
Modaff warned drivers to be cautious over the next few days.
"Thursday morning, drivers may notice water across the pavement, depending on exactly how much thaw we get, but that water will find its way to the drains and basins," Modaff said. "If a particular roadway is impassable, please avoid it and call 911 so we can get a crew out there as soon as possible to block off the area."
And if all that weren't enough, officials warn there's a chance of damaging winds late this week that could bring down trees and knock out power.
• Daily Herald staff writers Elena Ferrarin, Bob Susnjara, Melissa Silverberg and Russell Lissau contributed to this report.