Take me back to all courses!

International law is a culture of communication that “constitutes a method of communicating claims, counter-claims, expectations and anticipations, as well as providing a framework for assisting and prioritizing such demands” (Shaw, 2008). International water law is the law of the non-navigational uses of international watercourses.

In international water law there are two substantive principles that ought to be taken into consideration when sharing international water:

  • The principle of equitable utilization is the more subtle version of the doctrine of absolute sovereign territory. It argues that a (nation) state has absolute rights to all water flowing through its territory.
  • The principle of no significant harm is the delicate version of the doctrines of both absolute riparian integrity (every riparian state is entitled to the natural flow of a river system crossing its borders) and historic rights (where every riparian state is entitled to water that is tied to a prior or existing use) (Wolf, 1999).

Generally, upstream riparians favour the doctrine of absolute sovereignty, while downstream riparians favour river integrity or historic right. In reality these two extremes are rarely written explicitly into water sharing agreements. Rather, the more moderate equitable use and obligation of no significant harm are often used (Wolf, 2007).

International water law developed quite slowly until the middle of the 20th century. Treaties that focused on water allocation and use issues primarily gained momentum after 1930 (McCaffrey, 2013).

There are two highly relevant international water conventions for transboundary water cooperation. The 1997 Convention on the Law of the Non-navigational Uses of International Watercourses, and the 1992 UNECE Convention on the Protection and Use of Transboundary Watercourses and International Lakes (which recently broadened its membership beyond the EU to a global audience).

The soft law of the Sustainable Development Goals (SDGs) provides further impetus to the management of transboundary water resources directly through Goal 6.5: implement integrated water resources management at all levels, and through transboundary cooperation as appropriate, and indirectly through Goal 16: promote peaceful and inclusive societies for sustainable development.

Recommended Reading

Rocha Loures F & Rieu-Clarke A (eds) (2013) The UN Watercourese Convention in Force: Strengthening international law for transboundary water management.Earthscan, Routledge.

Centre for Water Law, Policy and Science (under the auspices of UNESCO):

Protected Areas Law