Good grief...
I’m serious. It is long established water rights law. It was a very heated thread, as you might imagine, but the long and the short of it is that it is the law. I don’t agree with it but not for the legal reasoning involved. That is pretty sound. What falls short for me is the idea that all of the water that hits the ground will end up in the drainage or water table. Someone introduced some scientific studies that backed me on that point.