I don't work on the legal side, but easements are generally designed to be permanent forever, with some caveats. For example, I believe most conservation easem

I don't work on the legal side, but easements are generally designed to be permanent forever, with some caveats. For example, I believe most conservation easements have some language that allows them to be essentially "moved" in certain circumstances. Say the city needed to build a road through an easement - than that easement could be exchanged for a similar parcel that was conserved in a similar manner nearby or similar. But outside of that and similar narrow exceptions, conservation easements are generally designed to be forever.