This is an issue that we hear about all the time! Your best bet is to try to work out a solution with your neighbor. If that isn't possible, it is an issue for civil court.
In addition, the Greenville County Soil and Water District Manager can offer technical advice. She will speak with you about your issue and advise on how to address your situation.
To speak with Kirsten Robertson, call 864-467-2755 or email kirobertson@greenvillecounty.org.