I've discovered that the water needs to be running and it must come from an artificial source, so far. If I'm in the shower or bath, for example, I can manipulate that. I can determine which water I travel to, as well, and the distance does not matter from my understanding.
I was able to travel to a place called New Orleans, which I gather is even further south than we are currently. Based on a map I saw, it seems it's on the other side of this land mass. I've yet to experiment with traveling to other places, but as long as I have an idea of the place, I'm able to control myself traveling there.