David Cassuto

I am fresh off the plane from Paris (a little snowy but great falafel) where I attended the UNESCO/ISARM Conference, “Transboundary Aquifers: Challenges and New Directions.” ISARM stands for “Internationally Shared Aquifer Resource Management.”   The conference provided a fascinating window into the management issues facing transboundary aquifers. As yet, despite the existence of some 273 transboundary aquifers, there are precious few multilateral agreements governing their use. The reasons for this are many, including the relative dearth of knowledge about aquifers, a consequent lack of international (or domestic) law on the subject, and the myriad problems that inevitably arise regarding the management and use of biologically critical resources.

One significant area of contention involved the notion of sovereignty. Many at the conference (a number of whom were diplomats who helped draft the recent UNGA Resolution on the Law of Transboundary Aquifers) feel that sovereignty must form a crucial component of any multilateral agreement on aquifer management. They feel that the Resolution properly qualifies the term and renders it subject to existing principles of international law, including equitable and reasonable utilization. Others feel that sovereignty over a dynamic resource that flows under multiple borders is a deeply problematic concept and that the definition adopted by the UNGA resolutions is seriously flawed.     

I, along with my co-author, Romulo Sampaio from FGV Direito Rio, gave a presentation on the recent Agreement on the Guarani Aquifer (find it here in Portuguese) signed but not yet ratified by Argentina, Brazil, Paraguay & Uruguay. The Guarani is the largest aquifer in the world. It contains 30 trillion m3 of water, 1.2 million km2 of surface area and comprises one of the most important eco-regions in the world. It is integrally connected through overland rivers (the Parana and the Paraguay) with the Pantanal, the largest wetland in the world, which oversits Bolivia, Paraguay and Brazil. The health of the Pantanal and that of the Guarani, both of which reside in the La Plata River Basin, are inexorably intertwined and the issues created by that transboundary overlap presents a complex management dilemma. Furthermore, the region’s delicate ecology faces a present and growing threat from climate change, extractive industry, and the expansion of the agricultural frontier.

As you can imagine, the Guarini would present complex management dilemmas even if it underlay only one country. Since it underlies 4 nations, those challenges multiply exponentially. We argue that even more pressing than the sovereignty issue is the need for the various signatory nations to minimize known uncertainties through clarifying their respective laws regarding groundwater use and management. In Brazil, for example, it remains to be determined (perhaps by constitutional amendment) whether groundwater law – transboundary or no – is the exclusive province of the states. If the answer to that query is yes, then the nature of the Agreement changes significantly.

We believe that our recommended approach – which attempts to map and minimize known uncertainties (which we call “soft uncertainty”) will also help identify unknown unknowns (“hard uncertainty”) and thereby strengthen the Agreement and better enable signatory nations to cope with future perturbations, including those caused by climate change.