Neighbor puts sign up on open house day!

[Charlie Hampton]

Long story short, neighbors yard is lower than mine and he has been complaining about standing water after torrential downpours. County came out twice and said its not my problem; he has too much pavement and too many downspouts (multiple out buildings) going to one point. I have done everything but pay this mans taxes to appease him. The day of my open house he puts this sign out. Is there any legal recourse for this?