I do watch with interest, where the dogs in the boarding drink from.
I have put the self filling water dispensers into their individual units. That way I ensure they all have fresh, clean and cool water available at all times but I also collect storm water into a butt and have a bowl below which I keep filled. As the dogs are let out regularly they have a choice and many do prefer storm water. This will not come as a great surprise as many of you have told me your pets enjoy drinking out of puddles, often muddy. Here they have a choice too :)