Well, there are a few issues here but it is difficult to give good advice since we don't have all the facts/maps/zoning/etc.
Theoretically, if the City tries to sell the property, which was donated in perpetuity, there is probably language in there that it reverts back to the estate which donated it if the City ever tries to sell or use it for a purpose other than what it was donated for. So that could be a big problem.
As far as the potential easement goes, it could be a necessary easement for access to your property but that may be hard to prove since you have access through another street... You'd really need to find an attorney who can look at all the different options and help you make the best decision.
Thomas A. Schaeffer, Esq. Law Office of Juarez and Schaeffer PO Box 16216, San Diego, CA 92105 (619) 804-4327 www.jslaw.org This posting is provided for "informational purposes" only and should not be relied upon as "legal advice." Nothing transmitted from this posting constitutes the establishment of an attorney-client relationship. Applicability of the legal principals discussed here may differ substantially in individual situations or in different States.