As a body of rules and a basis for inter-State cooperative practice, international water law suffers from certain important shortcomings. Most significantly, it is characterised by substantive normative indeterminacy, and from related deficiencies in its associated procedural and institutional frameworks, which retard its progressive development and limit its capacity to respond to the looming challenges of the impending global water crisis. Though it has evolved progressively in recent years to incorporate a far-reaching obligation upon watercourse States to adopt an ecosystem approach to the management of shared watercourses, this very development highlights international water law’s systemic difficulty in accommodating water management techniques which are critically important to effective implementation of such an approach and, ultimately, to addressing the water crisis. Such techniques, with which international water law struggles, include multi-faceted benefit-sharing, adaptive management, and public and stakeholder participation. The latter two are considered essential for implementation of an ecosystem approach, while the former comprises a cooperative technique facilitated by an ecosystem approach, by means of which watercourse States might eliminate inefficiencies and ensure optimal utilisation of shared water resources. These problems illustrate the urgent imperative of continuing to develop and refine, if not completely reimagine, the rules of international water law.