Who owns the land?

In March last year, the Whanganui River became a legal entity. In New Zealand courts, the rights of the Whanganui River can be considered. The River has personhood in our courts of law in much the same way as a company does.

Could the Whanganui River own land?

What if the land we lived on wasn't owned by us, but by our nearest significant natural feature: A river, lake, mountain or stream. How might this change how we relate to the land we live on? What would the relationship look like?