International Groundwater Law: Towards Closing the Gaps?

There is a clear contrast between the social, economic, environmental, and political importance of groundwater and the attention international law has paid to this resource. Groundwater represents about 97 per cent of the fresh water resources available, excluding the resources locked in polar ice. More than one-half of the world's population is dependent on it for its basic needs. Accelerated population growth in the latter half of the twentieth century has coincided with improvements in pumping technology and has led to a greater and greater use of, and reliance upon, this resource, especially in the arid and semi-arid regions of the world. In consequence, over the last fifty years, groundwater resources and the social, economic, and environmental systems dependent on them have come under threat from over-abstraction and pollution. International law has only rarely taken account of groundwater. While surface water has been dealt with in numerous international agreements and other instruments, groundwater is either nominally included in the scope of these instruments, primarily if it is ''related'' to surface waters or part of a ''system of surface and groundwater'' (see the United Nations Conventionon the Non-Navigational Uses of International Watercourses (Watercourses Convention) or the 2000 Revised Protocol on Shared Watercourses in the Southern African Development Community (SADC Protocol)), or intentionally or unintentionally left out. Few treaties and other legal instruments exclusively address groundwater or contain groundwater-specific provisions. Hence, two gaps can be ascertained: an overall lack of addressing groundwater in international law (a formal gap) and a lack of groundwater-adequate rules in cases where groundwater has been addressed (a material gap). These need to be closed. An analysis of recent binding and non-binding legal instruments reveals some indications of emerging rules of groundwater management. In addition, the International Law Commission (ILC) is currently considering the topic Shared Natural Resources, comprising oil, gas, and transboundary groundwaters. Its special rapporteur for the topic, Chusei Yamada, presented a first set of draft articles on transboundary groundwaters in May 2004, which might contribute to closing the gaps by leading to a new legal instrument. The objective of this article is to analyze the limitations of the existing legal regime and to discuss and assess some emerging principles of groundwater management. The first part will contain a concise introduction to the specific characteristics of groundwater and the most common reversible and irreversible problems faced in its management. Second, against this backdrop of facts, an overview of the current legal regime and its shortcomings will be presented. Groundwater as the subject matter of the Watercourses Convention, of bilateral and multilateral treaty law as well as of non-binding instruments will be examined. Third, some emerging legal tendencies will be discussed, which might indicate the way for more groundwater-adequate legal regulation.Finally, the already-mentioned activities of the ILC will be outlined.