Flood info for traveling from Iowa City to Log Jam Festival:
Iowa DOT Travel Infomapquest says to take W80 to 380 North to 218 North.
On 380 - there are several construction zones and single lane closures, but there does not to appear to be any detours due to flooding (there are a few ramp closures, but you should be able to get out of the area before needed a pit stop)
On 218 - one zone of road construction, width limit of 12\'
Next take N27 to N35 towards West I94. Once you hit 35, you should be almost to Minnesota. Once in MN, I did not find any road dtours/closures on your route, other than some construction zones.
you can check by highway number here:
Minn DOT Work Zones/News Releases - you can search by specific highway number from the pull down box on the mid-right.