Surface water - Complaint of the neighbors

Sorry, he floods his property and blames you for it? He can't do anything to you.

That's almost as cool as the guy here in town. He lets his dog poop in our front yard (there's still a pile of sand there, where the kids also play) because he's pissed off that there's a new housing development on the field now and he can't walk the dog here like before.

OK... Now his mutt doesn't poop here anymore.

He can no longer drain to us now because we are higher than him. Our water flows forward into a [Gully].

Is he just complaining or has he made any demands?

Complains and says that WE have to change that!

*facepalm*

Which federal state are you from? In almost every state building code there is something appropriate about drainage. I would look for that and ask him if he knows it.

Can you still basically talk to him or is the relationship already too damaged?

Oh, can you upload one or two pictures where you can see the situation?

In Lower Saxony. Let's see if I can find a picture. You can already talk to the neighbors, they are actually quite good about it. It just annoys me. I had informed the neighbors in advance that it would be like this and offered them to share our wastewater so they wouldn't have to dig up their garden, this was declined. And now this!