ROCKFORD (WIFR) -- The Rock River has been quite busy and now some boats may no longer be welcome.

The Illinois Department of Natural Resources says if it doesn't rain soon larger boats may be banned. That's because the river level is becoming dangerously low. The National Weather Service says the latest measurements show we're between four and six feet below what we were this time last year. That means some boats may run the risk of hitting rocks that are normally submerged. Low water levels have historically lead to fish kills as well. Our camera caught one dead fish, but we don't know the cause.