It shouldn't be a deal killer. You will want to talk to your insurance company as they will be taking a look at this anyway.
I live in Franklin Park and don't recall any major issues with flooding near Silver Creek. You can contact the Village Hall and talk with them as well at 9500 W. Belmont, 847-671-4800.
If you are concerned that your home will actually flood, besides the disclosures provided by the seller, I would talk with some long time neighbors and ask them if their homes have flooded. With the big storm we had in August, you should be able to get a sense for what might occur in the immediate area by talking to others.