The water will not freeze solid because of the insulating quality of the wooden 2x6s.
For a couple chickens one holder can be for food and water, for more numerous chickens, 2 water-ers can be lined up in the holder. Use a larger holder for as many jugs as you want.
If ice does form, it breaks out easily to empty with a tap on the ground or a tree.
This is an easy way to provide clean, wet, fresh water for (essentially) free!