Does your county or township have a drain commissioner?
Does the culvert cross the road?
Were all the necessary permits received to install the culvert?
I think there might be some recourse here before just "dealing" with it. As Darryl stated, most of the time someone can't just do whatever he wants with runoff.
"Science is the belief in the ignorance of the experts" – Richard Feynman
Guns don't kill people, abortion clinics do.