Green Bay has 407 miles of storm sewer across the city.
After Northeast Wisconsin experienced warmer temperatures on Wednesday, the slush created by melted snow started clogging drains.
If you don't clear the grates, crews say it could create a mess when Thursday's storm hits.
The city is trying to spread the word to residents, asking them for help.
Chris Pirlot, the Operations Director with the City of Green Bay, referenced their "adopt a grate or inlet program," simply asking residents to clear any drains from accumulating snow.