Legal and institutional cooperation over transboundary aquifers

Legal and institutional cooperation over transboundary aquifers

International law applicable to transboundary groundwater, one of the five focus areas of ISARM, has seen a substantial progress in recent years. This page gives a brief overview of activities conducted in the last several years (additional information on related documentation can be found at the site of the UN ILC).

Legal and institutional cooperation over transboundary aquifers Legal and institutional cooperation over transboundary aquifers

In 2002, the UN International Law Commission (ILC) , which is the UN body in charge of the progressive development of international law and its codification, has included the topic of "shared natural resources" in its work programme. Under the topic, it has chosen to cover transboundary groundwater, and then oil and gas. The Special Rapporteur Ambassador Chusei Yamada proposed to start by the study of groundwaters. And in 2008, the ILC adopts at second reading the draft articles on the law of transboundary aquifers (19), which marks the end of a process of 5 years.
Since 2003, in the framework of the ISARM Program and its focus area on the legal issues, at the request of the Special Rapporteur,  close cooperation between UNESCO's International Hydrological Programme (IHP) Secretariat and the Special Rapporteur of the UN ILC  has been established. The IHP is committed to provide the Special Rapporteur with scientifical, technical and legal support on the issue of transboundary groundwaters. During these years IHP has invited and coordinated the contributions of international experts, international and national institutions, and centres on groundwater resources, such as the International Association of Hydrogeologists (IAH), FAO, the International Groundwater Resources Assessment Centre (IGRAC) and the United Nations Economic Commission for Europe (ECE). 

Five reports were prepared and debated at the UN ILC:

  • The first one was submitted in 2003, (A/CN.4/533, pdf 0.08MB ) and addressed the background of the topic. The addendum (A/CN.4/533/Add.1, pdf 0.39MB) provided a hydrogeological overview of the groundwater resources of the world.
  • The second report (A/C N.4/539, pdf 0.07MB) presented in 2004 includes several draft articles for a future transboundary groundwater international legal instrument, while the addendum (A/CN.4/539/Add.1, pdf 0.09MB) provides case studies and a selected bibliography on the topic.
  • The third report A/CN.4/551 presented in 2005 together with a corrigendum and addendum included a full set of draft articles on the law of transboundary aquifers. The report was considered at the 57th session of the ILC in May 2005, and a Working Group was established. However the Working Group did not finish its task.The work of the ILC was also, like the previous years commented at the 6th Committee of the UN GA in New York.
  • At the 58th session of the ILC, in 2006, the Special Rapporteur did not submit any report. The Working Group was reconvened to complete its task. It submitted a report (see its report A/CN.4/L.683) containing 19 revised draft articles, which were adopted by the ILC at first reading (see the ILC report). The draft articles were transmitted for comments and observations to be submitted by 1 January 2008.
  • In 2007, the Special Rapporteur submitted his fourth report (A/CN.4/580). The aim of this report was to recommend the separation of the work on transboundary groundwaters from the work on oil and gas, and that the Commission should proceed with and complete the second reading of the draft article on the law of transboundary aquifers independently of any future work on oil and natural gas. The ILC followed this recommendation.
  • Finally in 2008, the Special Rapporteur submitted his last report (A/CN.4/591) in which he presented the draft articles and their commentaries in a revised version, after consideration of the comments received from Governments (47 in total). The draft articles are intended to offer States a framework for their agreements on transboundary aquifers. They are divided into four parts: Introduction, General principles, Protection, preservation and management, Miscellaneous provisions. The draft articles apply to the use of aquifers and transboundary aquifers, to other activities that have or are likely to have an impact upon those aquifers and aquifer systems; and to the measures for the protection, preservation and management of those aquifers and aquifer systems. The second article defines the word aquifer, aquifer system, recharge zone and discharge zone. The part on General Principles include the principles of international water law the equitable and reasonable use, and the obligation not to cause significant harm, both adapted to the case of transboundary aquifers; as well as the general obligation of international law, the obligation to cooperate with its practical implication the regular exchange of data. In its third part, the draft articles include more technical provisions such as the protection and preservation of ecosystems, or related to recharge and discharge zones, to the prevention, reduction and control of pollution, to monitoring and to management, encouraging States to establish joint mechanisms. Finally the last part includes inter alia an article encouraging the scientific and technical cooperation with developing States, directly or through the competent international organizations. UNESCO-IHP supports and encourages such a cooperation on transboundary aquifers in various regions of the word through its ISARM project.

The draft articles on the law of transboundary aquifers

The ILC adopted the draft articles at second reading, and according to its Statute deferred them to the UN General Assembly with the following recommendation:

  1. a.) To adopt a resolution taking note of the draft articles on the law of transboundary aquifers and to annex these articles to the resolution; b. To recommend to States concerned to make appropriate bilateral or regional arrangements for the proper management of their transboundary aquifers on the basis of the principles enunciated in these articles;
  2. To consider, at a later stage, the elaboration of a convention on the basis of the draft articles.

At the last session (6 October to 14 November 2008) of the 6th Committee of the General Assembly (Legal), more than forty States commented the achievement of the ILC on the law of transboundary aquifers, expressed their satisfaction and their support of the two steps approach recommended by the ILC. On this basis, a draft resolution was prepared for submission to the GA, and adoption by mid-December at latest. On 11 December 2008, the UN GA adopted Resolution A/RES/63/124 on the law of transboundary aquifers.

In the frame of its assistance to the Special Rapporteur and to the UN ILC, UNESCO-IHP organised in June 2004 a regional meeting (report, pdf 0.17MB) with experts from the Arab world (hydrogeologists and lawyers). The aim of the meeting was to hear the regional view on transboundary aquifers and to benefit from the experts experience in the field. Another meeting (invitation, pdf 0.11MB) was also held in March 2005 with groundwater experts from the Americas. The report from this meeting is released . All the documents, papers and presentations from these meetings are now available on-line!.
Groundwater experts from UNESCO-IHP participated in a briefing organised in October 2005 by the Japanese Mission in New York at the attention of the delegates of the 6th Committee (see report).

In October 2006, UNESCO-IHP organized a Special Presentation for the delegates, in view to provide the background information on transboundary aquifers. The meeting included formal presentations by groundwater experts, followed with questions and answers. 

And last but not least, UNESCO's International Hydrological Programme along with its long time partners the Académie de l'Eau and the Bureau de Recherche Géologique et Minière, or BRGM, (i.e. the French Geological Survey) organized 29-30 May 2007 a workshop on transboundary aquifers with the objective of affirming the interdisciplinary nature of water management as well as the necessity to create a common language between the different disciplines. 

The workshop was the opportunity to present the draft articles on the law of transboundary aquifers that were adopted at first reading by the UN International Law Commission in June 2006. Ambassador Chuseï Yamada, Special Rapporteur of the UN ILC on the topic, attended the workshop and informed the participants on the work of the Commission, and the future steps in the process of adoption of the draft articles. 

The participants to the workshop were legal advisors from Ministries of Foreign Affairs, and water experts (including lawyers) from the Ministries of Environment from several countries (France, Germany, Portugal, Spain, the Netherlands, Greece and Saudi Arabia), as well as groundwater experts. 

This workshop was the occasion to underline the importance of transboundary aquifers across the world and the stakes that now represent the adoption of the draft articles at first reading by the ILC. It was also a further opportunity to affirm the interdisciplinary nature of water management.

For more information on the draft articles please contact (Raya Marina Stephan (, UNESCO-IHP, 1 rue Miollis 75732 Paris cedex 15 France, tel : +33 (0)145684115..


Alice Aureli, Groundwater Resources, UNESCO IHP; e-mail:
Raya Marina Stephan, Consultant, UNESCO IHP; e-mail