The proceduralisation and growing maturity of international water law

The recent judgment of the International Court of Justice in the Pulp Mills (Argentina v Uruguay) case makes a very important and timely contribution to the ongoing development of international law relating to shared international water resources and to international environmental law more generally. It does much to clarify the relative significance of the procedural obligations imposed upon co-riparian States and the nature of the relationship between procedural and substantive rules of international water law and international environmental law. In particular, the Court has stressed the importance of inter-State notification of new projects or activities, linking notification to discharge of the customary due diligence obligation to prevent significant transboundary harm. In turn, it has found that a process of environmental impact assessment (EIA) is absolutely central to such notification and, therefore, that EIA is an essential requirement of customary international law in respect of projects or activities potentially having transboundary effects. Unfortunately, the Court was not prepared to identify the minimum core components of an adequate EIA. In addition, the Court has confirmed that, in the specific context of shared international water resources, the principle of equitable and reasonable utilisation, universally accepted as the cardinal rule of international water law, is virtually synonymous with the concept of sustainable development. This finding confirms that the former principle 'operationalises' sustainable development in respect of international water law and further suggests that considerations of environmental protection are absolutely integral to the equitable balancing of interests involved therein. Generally, the judgment makes it clear that the principle of equitable utilisation ought to be understood as a process, rather than as a normatively determinative rule.