International Law for Transboundary Aquifers: A Challenge for Our Times Academic Article uri icon


  • Quarrels between states sharing a transboundary aquifer (TBA) have been relatively minor in comparison with the more boisterous disputes seen in many of the world's shared river basins. Yet, transboundary groundwater can easily serve as the basis for cross-border disagreements. Twice as many TBAs and shared groundwater bodies have been identified globally as compared to transboundary rivers and lakes, and the volume of accessible groundwater exceeds all surface waters by a factor of one hundred. Yet, the number of treaties in force for TBAs is miniscule in comparison with those for transboundary rivers and lakes. Moreover, dozens of nations exploit groundwater from a TBA, often unilaterally and without knowing the cross-border implications, or even that the aquifer is transboundary. The lack of prioritization of groundwater in international practice and law, coupled with the reality that groundwater is “out of sight,” and thereby “out of mind,” has relegated shared aquifers as the neglected stepchildren of international water law. But, with many of the world's nations experiencing growing water scarcity and stress, this situation undoubtedly will change. This essay highlights the growing pains of international groundwater law and the challenges for its identification and articulation. Specific hydrogeologic characteristics of various TBAs are presented and, where relevant, placed in the context of water scarcity and security and recognized international legal norms.

published proceedings

  • AJIL Unbound

altmetric score

  • 3.95

author list (cited authors)

  • Eckstein, G.

citation count

  • 0

complete list of authors

  • Eckstein, Gabriel

publication date

  • May 2021