Filling fresh water tank before trip, good or bad?

to me it all depends on where I am going to camp. some have water and some don't. there are places I know that will let you fill up with water esp if you are buying a full tank of gas from them. Most of the time I just travel with enough water to use the toilet during travels. then I just use full hook ups when I get to camp. If in the mountains then I fill up at home and I have even brought several 5 gallon jugs to tied us over the week