I dont think its a slippery slope. We've had non natural persons in law going back to the romans.
The problematic part here is, how do you determine what a river "wants". Maybe it wants to be polluted the way some humans want to smoke. Ok, maybe not, but still, it seems like this is the wrong tool for the job. Why not just use some sort of environmental easement, or pass some law making it a protected river.
There are multiple slippery slopes, some good, some bad.
It’s a slippery slope to a national park system. It’s also a slippery slope to a public-private partnership to maintain natural sites.
Both are great.
It’s also a slippery slope to a system where natural entities receives court appointed “guardians”, who sue and defend based in the interests of their client, whatever that means.
That would be a mess.
There really needs to be some sort of board, selected by parties with interests in the well-being of the river.
The problematic part here is, how do you determine what a river "wants". Maybe it wants to be polluted the way some humans want to smoke. Ok, maybe not, but still, it seems like this is the wrong tool for the job. Why not just use some sort of environmental easement, or pass some law making it a protected river.