Re: Idiot Neighbour Flooding my Garden
I think the best policy when it comes to disputes like this is to not lower yourself and to remain cool, otherwise he will be all over you when you have your radio that bit too loud, or friends around for a BBQ.
If you are going to report him to some authority then they will probably ask you if you have tried to resolve it between yourself, and if you can provide evidence that you have then you can move on to the next step. If you have tried talking then I would suggest a letter, and keep a copy for future use.
I had a problem with a shop making deliveries outside my window at 2am. I contacted environmental health and they told me I had a case but to try and sort it out first. I wrote a letter to the shop explaining that I had been in touch with EH and that while I had a case I would prefer to work it out amicably. As a result the shop reversed its delivery schedule so they start at mine at 7-8pm.
Just don't lose your cool with him, not within earshot.
Speak softly and carry a big stick.