Note that I'm no longer directly participating in RDGC board activities, so my info is based on the situation earlier this year -- I'm not aware that anything has changed, however. The Roswell Recreation and Parks Department does not charge a fee for use of the disc golf tournament for events. However, it does require that any events be coordinated through the Roswell Disc Golf Club, and that an RDGC representative be present for the event. Furthermore, there is a requirement for at least one RRPD maintenance/grounds employee be present for the duration of the event, at a rate of $15/hr. For Sunday events, this may require special arrangements since the maintenance guys are usually not working on Sundays.
For anyone interested in running an event at ERP, the best advice is to contact one of the active board members (Imran Khan, Jason Bradshaw, Brett Porter, Andrew Lofstrand, and I think Chris Parker or Tim Acker) and ask them to help facilitate a discussion about it at the next RDGC board meeting.