As some of the camps in DV actually have running water (as well as electricity, hook-ups, ...), and are close to amenities, it's not as obvious as it might seem at first, it seems to me... Better, I think, to err on the side of caution.
Some people expect to find water at the campsites & trailheads. (I was asked by one guy where I got my water.) Plus, last summer a German tourist died in 5 hours from heat exhaustion...he hardly brought any water with him.
I believe the German fellow broke his vehicle, and tried to walk out to find help (his wife was with him?) - the warnings cannot be overstated: NO WATER, and ROUGH, REMOTE ROADS.
However, water can be found if you know where to look. Just a few miles south of The Racetrack, on the Hunter Mountain Plateau, there are several springs that support a nice pine forest, lots of willows and birch, and a small herd of wild horses.