rationalskepticism.org

I think there is a difference in the laws of most countries between saving small amounts of water for home/garden and limited business use, which would generally be allowed (or laws not enforced), and larger scale water collection systems which it is reasonable to control because such systems could have environmental effects, such as ruining the ecology of smaller rivers.

Members here who live in arid areas will probably know of major disputes about water rights, because where water is in short supply its an important issue.