Les cours d’eau internationaux et leurs utilisations en droit international

Water is a non-renewable resource. This has effects not only on its distribution and uses but also on its value. Moreover, the distribution of this scarce resource is not naturally balanced. The prevailing inequality of natural supply and the variability of needs, added to the vicissitudes of climate and differences of a geophysical, economic or cultural nature, also pose problems for the distribution and uses of this precious resource. It is hardly necessary to underline the tension and conflict that such a situation brings. International water resources law is a body of law that originated in the 19th century. It was originally focused on the regulation of navigation and transport uses for commercial purposes, and then gave way to other uses. Mainly shaped on the European and North American continents, it became universally applicable during the twentieth century, taking new contours along the way. The instruments that make it up apply principles such as equitable and reasonable sharing, the obligation not to cause significant harm, the duty of notification and consultation, institutional management and dispute settlement. The protection of the environment and the promotion of sustainable development also have their place. While international regulation of transboundary watercourses must take into account national territorial boundaries, it is important to go beyond them, both literally and figuratively. Sovereignty, the core issue, is often associated with unilateral measures. But it is unrealistic to stop there because the international character of the river involves the notion of sharing and apportionment among riparian states. Although the regulation of watercourses initially found its place within a logic of coexistence between sovereign entities, contemporary law is attempting to extricate itself from this logic of coexistence to make room for more communitarian notions, giving place to the satisfaction of basic human needs and the protection of the environment. The application of the principles relating to these uses rests with the riparian States. However, negotiation can lead to stagnation, if not crisis. Could a third party decide what is fair and reasonable or what choices to make between uses? If a judge were seized, how should he or she exercise the judicial function? A tentative opening was made in the Kishenganga case in the area of environmental protection. The arbitral tribunal did not, however, mention a possible role for itself in the future, but recommended that the parties look to the Indus Commission as a basin body to resolve any differences over the level of residual flow. Basic human needs and environmental protection are acknowledged as minimum essentialities that must be satisfied. However, the various uses of watercourses are not challenged per se by these imperatives. The law is currently limited to prescribing that the various uses of a watercourse make room for them. Nevertheless, it seems necessary to consider the steps to be taken to ensure that the protection and management of an international watercourse benefit from an overall vision, even if it means that choices must be made as to the uses of a watercourse. In this context, the concept of integrated management should receive attention. It is intended to take into account all human activities in the management of water resources and, in so doing, to allow a new articulation of needs and responses to these needs. Its application could lead to choices favoring sustainability going further than those based on human and environmental imperatives.