Period: May 2003
Groundwater Management in Transboundary River Basins
by Prof. G. Tsakiris



Although groundwater development has a long history (occurrence of wells have been noted even at Bronze Age), systematic exploitation of groundwater aquifers was realized during the nineteenth century. During the nineteenth century the advent of steam technology permitted the pumping from relatively shallow wells and later from boreholes. Today bores may be as deep as 500 m.

In contrast to surface water resources, groundwater has suffered from the “out of sight, out of mind” problem which makes management more difficult. This problem has delayed to the second half of the 20th century the licensing system for groundwater development and abstraction.

Generally speaking the quality of groundwaters is considered higher than that of surface waters on account of filtering of materials and degradation of organic pollutants during transit underground. Today in most cases groundwater sources require considerably less treatment than surface water sources whereas in some cases only chlorination is required. Due to this fact groundwater is preferred for high quality uses such as municipal water supply therefore increasing the competition from various consumption centres.

Finally groundwater is even more important for arid and semi-arid countries which base their water consumption on aquifers exploitation rather than the scarce and unevenly distributed surface water resources.



It is widely known that aquifers may have different functions according to the natural conditions and the anthropogenic interventions in the area. Some of them are:

  • Supply function

  • Piping function

  • Mining function

  • Filtering function

  • Storage function

  • Energy-source function

However the pressures on the groundwater resources are serious and have been intensified during the last decades. In summary here are some key points which cannot be analyzed further in this short text:

  • An aquifer can be over-abstracted therefore reducing the availability of the resource over time

  • Groundwater can be polluted

  • A badly managed aquifer can cause environmental damage (e.g. drying up of streams, lakes or   wetlands, sea water intrusion)

  • Aquifers may be damaged or destroyed by engineering works or mineral abstraction

The main obstacles towards effective and sustainable management of groundwater resources are among others:

  • Uncertainties in understanding and modelling of the aquifer (models cannot successfully model the heterogeneities and other complications (e.g. Karst) which may be found in an aquifer).
    Nevertheless substantial progress has been achieved in modelling of aquifers over the last twenty years (2, 3-D models, distributed models, unsteady flow simulations etc)

  • Lack of systematic measurements and permanent monitoring systems. As a consequence an evident lack of data is impending the use of scientific management.

  • Limited application of conjunctive use with surface waters. It is clear that the groundwater source is a sub-system of the entire water system of the river basin and as such should be utilized. Earlier approaches known as “safe yield of an aquifer” although the can be useful for reconnaissance studies, cannot be the basis of any management plan because they don’t exploit the dynamic characteristics of the water system and obviously do not respond to the various changes which are introduced in the basin over the years.



The problem of groundwater allocation is getting more difficult in the case of Transboundary river basins. There are many groundwater aquifers around the world which are related to “tranboundary problems”. Some 47% of the land and 40% of the population of the world live in transboundary river basins and therefore competition over the water resources in these basins is expected to be intensified over the coming years.

There are many conferences, meetings and conventions in many places of the world which are devoted to the principles of management of transboundary river basins. Relevant concepts and doctrines have been extensively discussed and supported in many such occasions. Although it is wise to avoid the repetition of views one should at least refer to the existing doctrines without commenting further:

  • Absolute territorial sovereignty
    (the upstream country where the resources and generated has full sovereignty over these resources)

  • Absolute territorial integrity
    (historical flows should not be changed)

  • Limited territorial sovereignty
    (compromise allocation recognizing the downstream country has some rights)

  • Community of co-riparian states
    (the co-riparian countries are encouraged to find ways of understanding convergence and collaboration)

Without further debate it seems that the last approach will prevail if countries wish to follow the road of peace and development rather than the permanent competition and conflict.

The groundwater aquifers as explained earlier are a part of the water system of the transboundary river basin and therefore should be treated as any other water resource of the basin.

This applies to all groundwater aquifers of the river basin regardless if they are crossed or not by a boundary between two or more countries. It is important to stress the various conditions under which groundwater aquifers may be represented by this general approach

  • Transboundary aquifer

  • Aquifer in the upstream country in a transboundary river basin

  • Aquifer in the downstream country in a transboundary river basin

  • Aquifer which partly belongs or influences the water budget of a transboundary river basin.

Obviously this type of holistic approach is the only way for achieving the widely accepted criteria of sustainable development, trans-generationality and a fair balance between strong and week partners.



UN and other world organizations have been involved in the formulation of what called “international law” on water issues and mainly on transboundary water resources. The most remarkable of them are the Helsinki Convention in 1992 and the New York Convention in 1997. It is understood that international law is a decentralized system relying mostly on the self-assistance and the opinion of the world community. Unfortunately international law lacks compulsory jurisdiction and centralized enforcement which are necessary features of national systems.

It is amazing to note that the General Assembly of the UN called upon the International Law Commission to prepare a set of “draft articles” on the “non-navigational” uses of International water courses. The commission worked for 23 years for the first draft and 3 years for the final draft (1994). The revised text of this draft after 3 more years of consultations was approved by the General Assembly on May 21, 1997 by a vote of 104 – 3.

This delay shows the difficulties encountered in tackling hot issues such as the transboundary water resources.

The situation considering the common management of transboundary river basins is clearer in Europe. According to the last EU directive (2000) riparian countries are encouraged to form joint management structures for dealing with transboundary water resources.

Therefore it is a positive contribution of this meeting to convey and strengthen the message to the riparian countries to realize in practice the EU directive articles concerning these delicate issues. It is the task of this meeting to emphasize the unity of the river basin in which groundwater aquifers are a part.

In conclusion, groundwater aquifers should be managed under cooperative management plans using a holistic approach for mutual long term benefits, development and sustainability for the riparian countries.


George Tsakiris

Prof. in Water Resources Management

National Technical University of Athens

President of the European Water Resources Association

President of the Greek Committee for Water Resources Management

Address:     National Technical University of Athens

                     School of Rural and Surveying Engineering

                     9 Iroon Polytechniou, Zografou Campus

                     15780, Athens, Greece.

e-mail:          gtsakir@central.ntua.gr


Past Editorials
Period: March 2003 - April 2003
European Water Resources Association
International Water Day (22 March 2003)
by the president of EWRA
Period: January 2003 - February 2003
UN Consecrates Water As Public Good, Human Right

by Dr. Peter H. Gleick
Period: July 2002 - December 2002
A Note on Hydropolitics in the New Era: 
IWRM, Sustainability, and the Search for Equity

by Prof. E. Vlachos
Period: February 2002 June 2002
From Single Purpose Planning to Sustainable Watershed Management
by Prof. G. Tsakiris
Period: December 2001 - January 2002
Formulating Water Resources Management Strategy
by Prof. G. Tsakiris