The governance of water is of increasing concern to policy makers. Several property rights systems, which allow for control of water by the individual, community, or state have been advocated, but no approach has been uniformly successful in resolving problems arising from competing uses. Recently, in an attempt to resolve challenges experienced under state control, a number of judicial rulings and statutes have used the 'Rights of Nature' approach to grant rivers legal rights around the world. Here we put forward the proposition that granting legal rights to rivers can be viewed as creating a new property rights system that we term resource self-determination. We test this model of resource self-determination against two cases where rivers have been granted legal rights in New Zealand and India to explicate how resource self-determination has been defined in each case. Although we find that the New Zealand decision results in a more clearly defined property rights system than occurs in India, in neither context are the new bundle of rights complete. We conclude that in the cases examined, unless the definitional shortfalls are addressed, granting legal rights to rivers is unlikely to resolve the long-standing competing use problems affecting these rivers.