This article explores deep underlying assumptions about relationships between people and the planet, and how these translate into very different ways of relating to waterways in Aotearoa New Zealand. In te ao Mäori – ancestral Mäori ways of living – rivers and lakes are the tears of Ranginui, the sky father, mourning his separation from Papatüänuku, the earth mother, and people are their descendants, joined in complex whakapapa that link all forms of life together. In modern ways of thinking, on the other hand, ideas such as private property, resource management and ecosystem services can be traced back to the Genesis story of God’s gift of ‘dominion’ to Adam and Eve over fish, birds, plants and the earth itself, including waterways, in which all other life forms are created for human purposes. In successive Waitangi Tribunal claims, iwi have disputed these assumptions in relation to fisheries, tribal lands and rivers, and, in worldleading legislation, the Whanganui River has been declared a legal person with its own rights. In this article, the authors discuss different ways in which the rights of rivers as rivers might be understood in scientific terms, investigating the ‘geomorphic rights’ of the Whanganui River, for instance, and how rivers as living communities of land, water, plants, animals and people might be understood through ‘river ethnography’, an approach that aligns a wide range of natural and social sciences with mätauranga taiao – ancestral knowledge of other living systems. They also consider how current policy discussions might be informed by such framings, so that river communities across Aotearoa New Zealand may be restored to a state of ora – life, health, abundance and prosperity.