Many folks have said that a rabbit doesn't need water but this is not
correct. Rabbits do need water and will drink from a bowl or a creek.
Of course it does depend on the same things we require water for. The
temperature, how dry is the feed, how much has it rained, etc. I have
seen rabbits in my pen come for water just as quickly as they come for
food but I don't have much vegetation in it either. Not sure about the
wild rabbits but it seems we alway find them near some water source,
springs, creeks or some wetlands. This might be due to the lush vegetation
along those areas but it is a good place to locate them. Plan on some
source of water in your pen or your rabbits won't last long.

If nothing
more than a large bowl of water. I would also recommend feeding them
rabbit pellets as they get all the things they need from the pellets to
remain healthy. Too much green vegetation will make them sick. It
seems raised rabbits don't know this but wild rabbits do.