I seem to remember that the government claimed that even if you live remotely and collect rainwater in a barrel, essentially it belongs to them. Or at least it falls under the government's jurisdiction. Even if you dug your own cow pond, the water in it belonged to them.
As was said, every single drop of water anywhere in the nation no matter how it was obtained, snow runoff or anything else, theoretically belonged to the government. Whether they would allow you to use it or not was at their whimsical discretion.