On 20 March 2017 the New Zealand Parliament passed the Te Awa Tupua (Whanganui River Claims Settlement) Act, declaring the Whanganui River "a legal person" — Te Awa Tupua, "a single, indivisible whole" incorporating "all its physical and metaphysical elements." Not a resource. Not an asset on anyone's ledger. A person, with standing.
Behind that sentence is a long petition. Whanganui iwi chiefs first brought the claim to Parliament in 1873. Their descendants kept bringing it — through a river-boards act in 1891, a scheme in the 1930s that delivered nothing, the Waitangi Tribunal in the 1990s, and eight further years of negotiation — for 140 years across five generations before the 2017 settlement closed the file. A person had to sue for its own personhood for longer than most of the humans doing the suing were alive.
The Act doesn't give the river's water a lawyer. It creates Te Pou Tupua: two guardians, one appointed by Whanganui iwi, one by the Crown, who act jointly as the river's face in law. If the river needs to be a plaintiff, a defendant, or a party to a resource consent, Te Pou Tupua speaks for it. The whole framework compresses into a whakataukī plain enough to put on a sign at the river mouth — Ko au te awa, ko te awa ko au. I am the river, and the river is me.
What this is not, and it matters to say precisely: this is not a court that can find a river delinquent. Standing here runs one direction. The river cannot be sued, cannot default, cannot lose its personhood for silting a channel or flooding a paddock. What got engineered is representation, not obligation — a person now speaks for the river in disputes among humans over the river. Nobody has yet built the other half: an instrument in which the river's own maintenance of the water, the fish run, the reach, is the thing that gets checked, and, on failure, withdrawn from someone.
Metabolic Standing is a sketch of that other half. Whanganui is where you'd go to find out whether the first half is even buildable — a hundred and forty years, and it barely is.