See this article that states that the path of a Houston eruv was leased from the city for 50 years for $1.
https://jhvonline.com/mayor-signs-new-rental-agreement-for-h...
Does it need to be a metal wire? Or is, say, a plastic pipe enough? In the spirit of the other comments here, there are plenty of those already in place. Certainly with the involvement of the land owner, which in these cases probably are the city or the state.
It would be interesting to hear from someone who are involved in these traditions to hear their view.
In fact, an entire tractate of the Talmud, called “Eruvin,” is focused on discussing these topics. Most subjects regarding Eruvin are fraught with differing opinions of Jewish Law, and therefore it is of utmost importance that questions related to the Eruv should be discussed with a Posek (Jewish Legal Expert.
Not Jewish, I just enjoy systems of rules.