Easement Question

I think most areas have a law which prevents people from granting themselves an easement, right?  And if a person comes to own a parcel on which they had previously been granted an easement then the easement goes away.

My question is if this applies to governments as well.  A situation I'm dealing with at the moment is where the city owns a lot in a subdivision and the plat calls out a public utility, drainage, and irrigation easement along all lot lines.  If the city is the owner and also the grantee does the easement still exist?