ABSTRACT
This chapter provides a discussion of the priority accorded navigational uses over non-navigational ones in early agreements and state practice. It considers the position on priorities among different kinds of uses and looks at indications of the evolution of international water law through other lenses. Transboundary waters nourished the great ancient civilizations – known as the 'fluvial' civilizations – and drove their economies. The earliest entry in a Food and Agriculture Organization of the United Nations compilation of some 2,000 legal instruments concerning water resources is a grant of freedom of navigation on the Rhine made in the year 805 by Charlemagne to a monastery. Each international watercourse is unique, as are the states sharing it. Moreover, natural and human-related conditions do not remain static; they change over time. The UN Watercourses Convention may be considered a codification of the principles of the law in the field, which signals the emergence of equitable and reasonable utilization as the core principle.
