, Mike Johnson, director of the Fon du Lac Park District in East Peoria said it would be difficult to police the event.
“We encourage them to practise social distancing. I don’t know how likely that’s going to be in this environment,” he said.
“This isn’t a sanctioned event. We started having law enforcement present about five years ago because we will get a lot of fights on the beach.
"It’s the perfect element for a problem. You’ve got beautiful weather, a lot of alcohol and anywhere from 600 to 1,000 people.”
One attendee, Dan Murphy, said: “I’m just ready to tear it down.
"It’s going be a good time hanging with friends.”
At least 7,714 people have died in Illinois since the start of the pandemic, though the daily toll has fallen and remains low since peaking at 197 in May.
A statement posted on Facebook by the Fon du Lac Park District Police Department read: "With the annual White Trash Bash tomorrow, our agency wants to remind everyone that Covid-19 numbers are increasing in our area.
"Please use caution if your going to be out on the river this weekend. This event has the potential to expose everyone to the virus.
"Please use common sense and social distancing."
The force also posted a photo showing from a separate recent event showing dozens of people packed onto boats at close quarters, writing: "This picture... is not social distancing."
Following the event, one commenter wrote on Facebook: "I guess we'll know within 2 weeks of [sic] how safe it was."
Up to 1,000 people attend the event each year