There probably are some regulations that you need to check into for diverting water from a stream. I've heard that there are some basic laws that say as long as you don't change where the water enters and exits your property, you are OK, but that really needs confirmed.

Obviously, no one is suggesting you to do anything against the law.

But you have to consider if anyone will really care if you do anything.

Excerpt from Robert Crais' "The Monkey's Raincoat:"
"She took another microscopic bite of her sandwich, then pushed it away. Maybe she absorbed nutrients from her surroundings."