Parks can already be corporations. I don't know how it would be any different than Disney Land suing you for littering on their property. The whole issue is tragedy of the commons which often does not occur with private property. Maybe it should be a corporation owned by the people who live around it as shareholders, and they can bring a lawsuit against anyone that damages their property. In fact making public goods corporations like that beholden to their shareholders might help protect them better, like for instance sources of water and such. Shares can be tied directly to land and housing a certain distance from that public work.