ABSTRACT
This chapter reviews the chief mechanisms from around the world that have been implemented or proposed for the assessment, use, allocation, and protection of transboundary aquifers. It examines the vast majority of arrangements in existence, and identifies trends and priorities that may implicate the emergence of generally accepted international legal norms applicable to transboundary aquifers. The most recent arrangement for a transboundary aquifer is the 2015 Agreement between the Government of the Hashemite Kingdom of Jordan and the Government of the Kingdom of Saudi Arabia for the Management and Utilization of the Ground Waters in the Al-Sag/Al-Disi Layer (Al-Sag/Al-Disi Agreement). Formal agreements are not the only evidence of trends and priorities in the development of customary international law. State conduct in the form of informal arrangements can also serve as indications of emerging state practice. The chapter discusses the various arrangements to create a number of substantive responsibilities.
