The granting of rights to the Whanganui River in 2017 emerged as an outcome of Tribunal hearings relating to breaches of the Treaty of Waitangi, signed between MÄori chiefs and the British Crown in 1840. As this expression of a river as having legal personhood with rights reflects a distinctively MÄori perspective upon river systems, it offers the prospect for a new era of sociocultural approaches to river management in Aotearoa New Zealand. Using the Whanganui River as a case study, this paper explores prospective geomorphic meanings of river rights. The paper asks, âWhat role can geomorphology play in identifying, articulating and protecting the rights of a river?â Ancestral MÄori relations to the river based upon mutual codependence (reciprocity) are juxtaposed against geomorphic understandings of a river's agency as expressed through selfâadjustment, diversity of form, evolution, and catchmentâscale connectivities. Relations between river science and indigenous concepts of rivers, framed under the auspices of river rights, present opportunities for different approaches to river management.