Transboundary Aquifers: Global significance for Social and Environmental sustainability

Submitted by Hindi on Tue, 05/10/2016 - 12:15
Bhujal News Quarterly Journal, Jan-June, 2010


Transboundary aquifers are as important a component of global water resource systems as are Transboundary Rivers; yet, their recognition in international water policy and legislation is very limited. Existing international conventions and agreements barely address aquifers and their resources. Unlike transboundary surface water, transboundary aquifers are not well known to policy makers. Available international law does not adequately address the three dimensional spatial flow and storage in ground water and has limited application in conditions where impacts from neighboring countries can take decades, given that ground water response is slow compared to surface water (Yamada 2008). Its national sustainable management seems to be hampered by weak social and institutional capacity, and poor legal and policy frameworks. In a transboundary context, this can be even further amplified because of contrasting levels of knowledge, capacities and institutional frameworks on either side of many international boundaries(Puri,2002). Many transboundary aquifers are under environmental threats caused by climate change, growing population pressure, over-exploitation, and human induced water pollution.

Almost 96% of the planet’s freshwater resources are to be found in underground aquifers, most of which straddle national boundaries. The aquifers, which contain 100 times the volume of fresh water that is to be found on the Earth’s surface, already supply a sizeable proportion of our needs. Globally, 65% of this utilization is devoted to irrigation, 25% to the supply of drinking water and 10% to industry. Underground aquifers account for more than 70 percent of the water used in the European Union, and are often the only source of supply in arid and semi-arid zones. Aquifers supply 100 percent of the water used in Saudi Arabia and Malta, 95 percent in Tunisia and 75 percent in Morocco. Irrigation systems in many countries depend very largely on groundwater resources - 90 percent in the Libya, 89 percent in India, 84 percent in South Africa and 80 percent in Spain.


In order to gain a global assessment to study and better manage Transboundary aquifer resources, a number of agencies joined together in a major venture, the World-wide Hydrogeological Mapping and Assessment Programme (WHYMAP created in 1999 at the UNESCO General Conference of the Commission for the Geological Map of the World (CGMW). The programme aims at collecting, collating and visualizing hydrogeological information at the global scale, to convey groundwater related information in an appropriate way for global discussion on water issues and to give recognition to the invisible underground water resources within the World Heritage Programme. WHYMAP also brings together the colossal efforts in hydrogeological mapping, at regional, national and continental levels. The principle focus of the WHYMAP program is the establishment of a modern digital Geographic Information System (GIS) in which all data relevant to groundwater are stored together with its geographic reference. In its final form the WHYMAPGIS will contain a significant number of thematic layers, local and shallow aquifers, transboundary aquifer systems, depth/thickness of aquifers, groundwater vulnerability, geothermalism, stress situations of large groundwater bodies and “at risk” areas. The first of such thematic maps based on the WHYMAP, the “transboundary” distribution map (scale 1:50,000,000) has been published (Struckmeir et al., 2006).

The “WHYMAP-Transboundary” confirms that regional aquifers sometimes extend over large areas and the flow paths of groundwater in them, crossing national boundaries, can extend over tens or hundreds of square kilometers. The area of the largest systems known on our planet can even reach over 2 million sq km, and be shared by several countries. With thick saturated sediments, of up to 1,000 m, they form vast underground water storages. Although there could be massive groundwater resources in stock, in arid regions, with little contemporary renewal from rainfall, aquifers can be particularly vulnerable to overexploitation. The preliminary summary-inventory of the global distribution of transboundary aquifers shows that there are at least 273 such aquifers in the global continental land mass. First-ever world map of transboundary aquifers (UNESCO,2008) showing the inventory of 273 shared aquifers - 68 in the Americas, 38 in Africa, 65 in eastern Europe, 90 in western Europe and 12 in Asia depicts the aquifer locations and also provides information about the quality of their water and rate of replenishment by rainfall (Fig.1).


The presumed linkage between water resources of transboundary aquifers and social development is widely accepted. Recently international forum devoted to international water resources, e.g., the World Summit on Sustainable Development in Johannesburg, the World Water Forum in Kyoto, and the Dushanbe Fresh Water Forum, have stressed that human survival depends not only on national but also on international water. It follows that the role of transboundary aquifers in society and its security cannot be separated from any considerations of the natural and built environments (Puri, 2001). In this context, ‘‘aquifers and rivers’’ interdependency should be better appreciated the dry-season base flow of many rivers may be derived from transboundary aquifers. Large numbers of poor people in Africa, South America, and Asia rely directly on dry-season transboundary water resources for their subsistence ( Puri, & Aureli, 2005) .

The ‘‘water poor’’ in the transboundary aquifers context are those impacted by the following :

- Persistent threat to their natural livelihood base from hydrologic extremes
- Dependence of livelihood on cultivation of food or gathering of natural products that rely on transboundary waters
- Excess pumping resulting in greater drawdowns, and increased costs to the poor in terms of energy
- Contamination of transboundary water resources, and inability to use, or have no access to, an alternative source
- Vulnerable people who spend several hours a day collecting potable water, and whose security, education, productivity, and nutritional status is thereby put at risk
- Those living in areas with high levels of water-associated diseases (bilharzia, guinea worm, malaria, trachoma, cholera, typhoid, etc.) without means of protection

To date, social assessments for poverty alleviation taking account of transboundary water resources are rare. The interrelationship between integrated water resource management and poverty has not yet been generally recognized, as might be noted from the lack of reference to ‘‘water poverty’’ in many Poverty Reduction Strategy Papers ( Burke & Moench,2000).


The immense diversity of aquifer types and their configurations suggest that no one uniform approach is likely to apply to all transboundary aquifers. It is clear therefore that case studies under different conditions will be needed. Case studies should be so selected that each makes a contribution to the overall understanding to the management of transboundary aquifers. For the full understanding of Transboundary aquifers, more important will be the socioeconomics, i.e., the users of the resources, including the demands placed on the aquifers for a sustainable environment, especially where aquifer discharge maintains important habitats.



In selecting case studies, the factors that may be used to identify priority transboundary aquifers should include the following aspects.

Persistent transboundary aquifer resource management problems including the following:-

- Poor prediction of aquifer yields on one or either side of the national boundary
- High variability in transboundary aquifer properties and therefore high uncertainties
- Presence of unused or underused ground water resources on or other side of the national boundary
- Conflicting demands for the transboundary aquifer resource,such as between irrigation and industrial uses
- Significant environmental concerns arising from current water management practices
- High likelihood that current transboundary aquifer management practices are depleting the resource, either through overexploitation or by pollution.

There could be several other criteria applied in selecting the case studies, some of which could be focused on ensuring the study is not unnecessarily complicated. The characteristics that will make a transboundary aquifer suitable as a case study could include the following ( UNESCO,1993) :-

- The aquifer is well defined and is hydrologically distinct ideally excluding major inter-basin transfer arrangements
- Strong national and local support can be developed for the case study aims
- Good history of surface and ground water hydrometric data collection in at least some of the key sites
- Broadly comparable socioeconomic situations (If, for example, there is significant industrialization on one side, this could complicate analysis including demand forecasts. As a consequence, the details of dealing with such changes may be given greater prominence than the overall approach to improving the transboundary aquifer resource management.)
- On the whole, there is only one international boundary crossing the aquifer system, as bilateral evaluations are thought to be more effective, at least during the case study stage.


While in the national context the principles of depletion and contamination of groundwater resources are well observed and understood, though perhaps not well managed, in the transboundary context these same issues take on an order of magnitude greater in complexity. What does this mean? From a pure natural science perspective, no impact other than that initiated from, and transmitted through, the aquifer system is feasible. However, there is increasing evidence among the socio-ecological community that globalization is a central feature of the coupled human-environmental systems, or as termed by them, socio-ecological systems. Approximately 40% of the global population lives in one or another transboundary river or aquifer system, this is an intuitive observation in terms of the impact on the more obvious human ecologies. The impacts are less tangible, but not less significant on natural resources transboundary aquifer systems and interconnected with it.

In considering the drivers that affect quality and quantity in transboundary aquifers, most researchers accept that apart from the impacts of climate change, they are also subject to easily discernible local changes such as land use change, urbanization and associated with these changes a bewildering input of substances that enter the groundwater flow systems. They also accept that such change is global i.e. worldwide, and it is proceeding at an unprecedented pace, and in geographic scope, affecting river basins and aquifers in term of quantity and quality. This is confirmed in various assessments such as the Millennium Ecosystem Assessment (Emerton & Bos,2006) that has shown that global ecosystem degradation involving loss of ecological capital is intense in 2002, humanity’s global ecological footprint was exceeded by 23%. If this trend continues, the globalized human economy (comprising of demand on natural resources, including water from aquifers) is in ecological overshoot, from the impacts of global interdependence on goods and services ( Margat,2006).

In translating the impact of this change into aquifers, it is widely reported that aquifers are being overdrawn i.e. the groundwater resource is being pumped beyond the rate at which it is recharged consequently, in the majority of such aquifers, water is being drawn from storage (IWMI,2005) . As yet there are no definitively agreed figures of the global total of withdrawal from storage. Nevertheless, if one were to simply adopt the figure provided for one globally significant aquifer system, the High Plains Ogallala Aquifer in the United States, this alone is stated by Konikov and Kendy (2005) to be equivalent to a sea level rise of 0.025 mm, as noted above. If, to this is also added the volume drawn from storage in the North China Plains Aquifers, the Indo-Gangetic Plains Aquifers, the Guarani Aquifers and the Mexico Aquifers, for which somewhat unreliable figures are available, though the order of magnitude is well known, then the global “loss of transboundary aquifer storage” become an issue beyond intellectual interest. When combined with the risks to aquifer functions and to aquifer dependent ecosystems, the issue needs urgent quantification.

Why does loss of global aquifer storage require urgent quantification? Because economic losses, translated through environmental and livelihood losses will be difficult to reverse. The decline in flexibility of ecosystems that are linked closely with aquifers and groundwater in the lower income countries, may reach a “tipping point” beyond which they cannot be revived.


Groundwater, and especially transboundary groundwater, is often referred to as an “undervalued” resource, where an ecosystem approach underwritten by economic valuation can help in qualifying this significant, but vague characteristic, to quantify the degree of under-valuation in social and economic terms. The core of the issue is, paradoxically that groundwater presents many opportunities and advantages for national economic development and environmental sustainability. In many regions of the world, groundwater represents a reliable and resilient source of freshwater, upon which people have become increasingly dependent. Groundwater development has significantly enhanced local productivity and makes the resource accessible to a wide range of individual users. Mechanized boreholes/tubewells have allowed the access to be “on demand” and “just-in-time”. However, as a consequence of this apparent success the social, economic and environmental systems that depend on groundwater are under threat from groundwater overexploitation.

The evolution is dynamic and it is important to recognize the change of attitudes over time to these recent and rapidly expanding problems. Cheap and reliable borehole pumps were only introduced in the 1950’s and the scale and intensity of the abstraction have only been apparent in the last quarter of the twentieth century. Prior to this, groundwater was seen as a ubiquitous and reliable source of high quality water. As groundwater exploitation from increasingly deep transboundary aquifers grow, often with incentives of inappropriate national energy and agricultural pricing subsidies, drawdown effects are extending beyond national boundaries. However, the impacts of increases in energy prices are slowly being felt and as some countries experience dwindling tax revenues, they are forced to phase out national energy subsidy schemes. If the phase outs are not synchronized across national boundaries in transboundary aquifers, the consequences can be significant. Access to affordable energy is emerging as a priority groundwater issue and, as the economic fundamentals are imposed, there are also adverse social impacts as groundwater falls out of the economic reaches of the individual farmers as the consequence of limited economic access to energy and capital to pump increasingly deep groundwater. However, as groundwater depletion is being increasingly recognized as a major environmental issue, international funding institutions can also be expected to restrict financing groundwater resources development.


The scientific principles involved in the sound management of transboundary aquifers are well known and understood by groundwater specialists. These include an appreciation of the full system, i.e. from sources of recharge, to the regions of discharge, as well as the quantity and quality issues along the flow path. Usually the system is well described by the use of conceptual models through which groundwater specialists from across national boundaries can communicate well. Unfortunately sustainable management of transboundary aquifers goes well beyond developing consistent conceptual models. It needs in addition, synchronization of legislation, equivalence in institutional structures and consistency in socio-economic drivers and also a coherent application of the environmental protection criteria (World Bank,1999). Developing cooperation for sound management therefore requires an equal attention to these other drivers, which must follow upon the hydrogeological conceptual consistency. One of the key issues in developing cooperation is strengthening institutions such as Basin Commissions or Joint Bodies, so that these aspects can be addressed. There exists extensive literature and substantial experience in developing cooperation for the sound management of transboundary river basins. While many of the principles from this experience can be applied to aquifers, there are issues peculiar to aquifer behavior that should be precisely defined in the system so that cooperation can be made effective.


To conclude, this paper was intended to infuse the aspects of social, environmental, legal and institutional issues into the development, interpretation, and application of international legal concepts and norms relevant to sustainable management of transboundary and international ground water resources. There is presently a dearth of scientific knowledge among government officials, legislators, policymakers, jurists, and legal scholars about these aspects. This is especially evident in the treatment afforded to ground water resources in past international agreements and academic writings. Decision makers and lawyers alike must develop a stronger understanding of transboundary aquifers and processes so as to overcome common misconceptions, mislabeling, and general misunderstanding about precious water resources. The absence or ignorance of this basic knowledge, in many respects, has resulted in the poor management of scarce water resources throughout the world; at times, it has resulted in serious harm to people and the environment. While not a panacea, the inclusion and understanding of underlying science in the decision-making process can serve to achieve more balanced, scientifically based, and thoughtful decisions. Only through a full understanding of the various social, environmental, institutional, legal and policy issues, as well as the underlying science involved, can states use, manage, and protect their transboundary and international resources prudently and effectively and in such a way that the resources provide adequately for both present and future generations.


The author would like to acknowledge Dr. S.C.Dhiman, Chairman, CGWB for the encouragement to compile this paper. Thanks are also due to Shri Sushil Gupta, Member (SML),CGWB & Shri S.Kunar, Member(SAM) for the useful consultations and guidance .

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Regional Director, Central Ground Water Board, Dehradun

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