I have had similar from a few chickens - not all of them. These ones tend to "stock up" before going to bead, so they eat loads (and we tend to give them scratch about an hour before sundown) and then they drink lots - but only in the summer. In the UK, that's not all that hot usually but once we get into autumn and winter, it stops happening.
The other factor I found was the coup being too hot at night - then they seem to pee more during the night. If I could get it cooler, it got less, although didn't stop completely.
I hope that helps - it may not be the same as your issue but it was our experience here with some of the flock.