Posted by John Merchant on August 07, 2009 at 15:25:53:
This is a very hot topic w “the greens” and most anything you’d want to do could get you into deep and very hot water 
with your bldg & land dept if you tried to alter, curtail, dam or divert a natural water drainage without making proper application with them.
I just recently heard of a local person here in WA State who was driving by a property she owned when she spotted an old tire that someone had tossed into a creek on that land.
She stopped her car, got out, climbed the fence and was in the process of removing the tire from that creek when some gummint worker happened to drive by and saw what she was doing.
He stopped and ordered her to leave that waterway alone as she had NO RIGHT to alter, in any way, said creek or the waterflow…further telling her that he was going to file a formal complaint against her for messing with that creek, etc.
So I’d investigate before doing anything as somebody (maybe Al Gore or cronies) might attempt to cause you great trouble for messing with “the environment”.