I never worry about the water..only if it stops the gobblers from comming in..i've never noticed if it has any advantages to hunt around them..gobblers get alot of the water they need from the plants that they eat...
I have noticed two correlations to water. The first is early spring the spring seeps on the mountains green up earlier than the rest of the woods. Turkeys are attracted to the tender green shoots and the insects they attract. The other factor is security. Southern boys will tell you how much turkeys like to roost right over water. So close they can hear the poop hit the water. It's a security thing. The water helps keep tree climbing predators at bay. However the south is very flat in places and i see a preference in PA to roost on high ground rather than on the waters edge, but I've seen them do it enough times not to dismiss it. Also when the warm weather really sets in and it stays warm overnight i think the birds get thirsty after being in a tree all night in warm weather. If there is a small water source close to the roost sometimes they head right for it like a morning cup of coffee for us.
I had a small flock one spring do just that. It took me a week to figure out that they would go to water first thing in the morning and then head back up to the high ground to start scratching.
Down and back up every morning.