What I have found helps me in the water drinking department is to have a large water bottle(the refillable kind) next to me throughout as much of the day as I can. If I think I am getting "hungry", I take a big long drink from the bottle and go back to work. If I am "hungry" again a little while later, I will take a couple of big drinks.
If I am still hungry a while after that, then I will grab a snack, because my body evidently really needs nutrition, not just liquid.
I have been told by my MD, that we usually misinterpret the desire for water as hunger. If you wait until you are thirsty to get something to drink, you are actually putting yourself into a slightly dehydrated state, and generally not taking in enough water at that point to resolve it.