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Summary of the Global Groundwater Situation

(compiled by David Bethune - December 2006)

 

Overview

Groundwater is an important natural resource for the entire world, and especially the people of developing countries. Groundwater supplies potable drinking water, irrigation water, industrial water, and naturally filtered “base-flow” to the entire aquatic ecosystem (i.e. creeks, rivers, lakes and wetlands). Groundwater is well-suited for water supply, especially in rural areas, as it can: a) meet dispersed rural demand, b) be developed cheaply and progressively, c) is naturally protected from human contamination, d) is less drought and contamination-prone than surface water and e) is generally of good natural quality. The use of groundwater is gradually increasing worldwide as surface water resources are either already allocated, depleted or contaminated. Globally groundwater is estimated to provide about 50 percent of current potable water supplies, 40 percent of the demand of self-supplied industry and 20 percent of water use in irrigated agriculture.

In developing countries, the proportion of people who depend on groundwater for potable water supply is generally much higher than the global average and can reach as high as 80-100% (e.g. Central America and Caribbean). The case of India is worthy of specific mention since groundwater directly supplies about 80 percent of domestic water supply in rural areas, with some 2.8 to 3.0 million hand-pump boreholes having been constructed over the past thirty years. About 75% of improved village and small town water supplies in Sub-Sahara Africa are supplied by groundwater (IAH, 2005). Groundwater usage in a hand ful of African countries has been estimated as follows: Algeria: more than 60% water withdrawals from groundwater; Libya: 95% of withdrawals are from groundwater mostly from Nubian sandstone aquifers supplying 0.5 million m3 of water/day to coastal cities of Libya through large diameter concrete tunnels; Mauritania: 80% of population rely on groundwater; Nigeria: 70% of the rural/small town population depend on groundwater (IAH, 2005). In Central America, over 80% of water supply is from groundwater (Bethune et al, 2006) and in Bolivia about 70% of public water supplies are from groundwater (Mulligan and Bethune, 2006).

 

The United Nations (2006) report Water: A Shared Responsibility includes an important description of the global groundwater situation:

 

More data are needed on groundwater and aquifer systems, particularly for developing countries where the lack of adequate surface water resources is most extreme. Groundwater can be of great value, particularly in arid regions where surface water is often scarce. Although aquifers can be tapped to supplement inadequate surface resources, there are high potential risks if the aquifers are not replenished naturally or by human intervention. It becomes only a matter of time before these resources run out or become economically inaccessible. High levels of exploitation - more than 50 percent of recharge - are currently occurring in many countries in the Middle East, Southern and Northern Africa, Asia, certain countries in Europe, and Cuba. Tracking and comparing groundwater use to recharge volumes at national and sub-national levels is therefore vital - particularly for individual aquifers. This enables identification of areas where corrective action is needed to maintain groundwater development sustainability. Although, several large-scale efforts are underway to upgrade monitoring and networks, for example in Europe and India, groundwater assessment, monitoring and data management activities are for the most part minimal or ineffective in many developing countries and are being downsized in many developed counties. This is particularly true in both Asia and Africa where there has been a dramatic reduction in water monitoring programs. Increased financial investment is needed to increase understanding of groundwater resources and aquifer systems. Meanwhile, regions that depend on groundwater should develop more comprehensive water level and quality monitoring programs.

 

Segun Adelona (see IAH, 2005) from South Africa describes the groundwater situation in Sub-Saharan Africa (SSA):

 

Over 400 million rural populations in SSA are sustained by groundwater. The dependence on groundwater will continue to increase in both rural and urban areas of SSA as climate change and contamination from human activities is fast limiting the availability of usable surface water resources. Therefore the maintenance of stable water supplies for the increasing population in SSA and assuring the longevity of the resources for future generations depend largely on the role of hydrogeologists. Unfortunately, a number of constraints hinder the well-intention action plan of hydrogeologists working in SSA. The problems identified include the lack of basic data, absence of appropriate hydrogeological base maps, poor knowledge of the geology of the groundwater terrain, ill planned and poorly documented water well-drilling schemes, lack of infrastructural facilities, inadequate governmental support for scientifically designed hydrogeological surveys and groundwater data logging, the absence of a working legislature, inadequate training and insufficiency of trained hydrogeologists as well as poor incentives in the form of wages and working conditions. As a consequence, very little data-driven published or archival materials exist about measured quantities of groundwater resources in SSA. Hence critical water-related policies are made behind dark curtains adversely affecting the economy and lives of the people.

In the week before the July 2005 G8 conference of world leaders in the UK, IAH held it own “GW8” conference in London a contribution to the debate on poverty reduction in Sub-Saharan Africa (IAH, 2005). The meeting concluded that SSA faces major challenges:

  • Expertise on how to develop groundwater throughout Africa is decreasing in Africa ( Segun Adelona, South Africa and vice president of the IAH), due to a lack of appropriate training, poor recognition of groundwater professionals within countries and as Aids continues to take its toll. Existing capacity needs to used more effectively and significant efforts are required to build capacity, by provision of postgraduate training in Africa and overseas, developing new research partnerships between northern and southern institutions and broad provision of “hands on training” to those involved in the sharp end of water supply in Africa.
  • Existing information that is vital for developing groundwater resources is not readily accessible – the lessons learnt from successful or unsuccessful projects are not being used incrementally as a basis for new projects. As a result, some are drilling boreholes almost blind, with often very poor success rates and poor quality water – this is an ineffective use of funds. Even in new projects, the lack of groundwater expertise referred to above often does not allow proper collection of new data which in its turn would support future work.

 

  • During the water decade of the 1980s, provision of rural water supplies from groundwater with hand pumps was well fitted to demand levels, and the presumption that adequate groundwater resources existed was broadly valid. However, with population growth and urbanisation, many of the communities that were villages are now small towns, and small towns are bigger towns. With increasing per capita demand from domestic users, and for more diverse uses as well, piped systems become the newer aspiration. Then questions of groundwater availability and resource management (all against the background of climate change), together with increased need for protection against the new pollution sources which are often associated with urbanisation, place increasing burdens on both the information base and the technical capacity.

 

While the highest groundwater usage is generally in rural areas, many large cities in developing countries depend either entirely (e.g. Mexico City and Managua) or partially on local aquifers for their water supply. It is believed that more than 1.2 billion urban dwellers worldwide depend on well, borehole and spring sources. This creates huge problems when cities urbanize over top of groundwater recharge areas and over-pump in localized areas.

 

Groundwater had been traditionally used by tapping springs and diverting river baseflow, and in minor quantities by direct abstraction through wells and horizontal galleries, especially in arid and semiarid regions. The situation changed about 150 years ago, when the scientific basis for understanding groundwater occurrence and flow was established, and more so when, half a century ago, drilling machinery and well pumps became widely available. At present, a deep well can be drilled and installed in just in a few days or weeks. Thousands of drilling rigs of varied sizes and requirements are now available.

 

It is estimated that 70% of all groundwater withdrawals worldwide are used for irrigation, particularly in arid or semi-arid regions (citation?). Ground water development in rural areas of developing countries has been possible largely due to millions of farmers and collectives all around the world who have independently dug or drilled wells or tapped into springs or river base-flow. While this silent revolution (see Fornes et al, 2005) has had countless social and economic benefits, the lack of supervision and control has had negative environmental, social and economic consequences, which may make some aquifers vulnerable to reductions in quantity or quality in the mid and long term.

 

Key International Groundwater Declarations

 

The "Valencia Declaration" (Symposium on Intensive Use of Groundwater, held in Valencia, Spain, on December 10–14, 2002; see Llamas, 2004) includes three proposals:

 

1. Public administrations must play a key role in the planning and the integrated
management of water resources. Among other things, this implies understanding
and coordinating surface and groundwater and their relationship
with land use planning. To achieve these goals, water administrations of most
countries need to improve their hydrogeological capabilities much beyond
what has been the case in recent years.

 

2. In parallel with the above large scale planning, immediate groundwater
decision-making has to be performed at the local scale by institutions for
groundwater management, establishing a framework for the effective users’
participation in this management through the appropriate institutions. These
institutions require the active and democratic participation of all the users or stakeholders, who should be provided with an adequate training and knowledge on the hydrogeological principles.

 

 

3. International organizations should recognize the great diversity in hydrogeological
and socio–economic situations that make almost impossible to apply the same groundwater management tools everywhere.

 

The Alicante Declaration is the action agenda that resulted from the debates held during the celebration of the International Symposium on Groundwater Sustainability ( ISGWAS) held in Alicante, Spain in 2006. The declaration recommended the following actions:

 

  • Develop more comprehensive water-management, land-use and energy-development strategies that fully recognize groundwater’s important role in the hydrologic cycle . This requires better characterization of groundwater basins, their interconnection with surface water and ecosystems, and a better understanding of the response of the entire hydrologic system to natural and human-induced stresses. More attention should be given to non-renewable and saline groundwater resources when such waters are the only resource available for use.

 

  • Develop comprehensive understanding of groundwater rights, regulations, policy and uses . Such information, including social forces and incentives that drive present-day water management practices, will help in the formulation of policies and incentives to stimulate socially- and environmentally-sound groundwater management practices. This is particularly relevant in those situations where aquifers cross cultural, political or national boundaries.

 

  • Make the maintenance and restoration of hydrologic balance a long-term goal of regional water-management strategies . This requires that water managers identify options to: minimize net losses of water from the hydrologic system; encourage effective and efficient water use, and ensure the fair allocation of water for human use as well as ecological needs, taking into account long-term sustainability. Hydrological, ecological, economic and socioeconomic assessments should be an integral part of any water-management strategy.

 

  • Improve scientific, engineering and applied technological expertise in developing countries . This requires encouraging science-based decision-making as well as “north-south” and “south-south” cooperation. Further, it is important that funds be allocated for programs that encourage the design and mass-dissemination of affordable and low-energy consuming water harnessing devices for household and irrigation.

 

  • Establish ongoing coordinated surface water and groundwater monitoring programs . This requires that data collection become an integral part of water-management strategies so that such strategies can be adapted to address changing socio-economic, environmental, and climatic conditions. The corresponding data sets should be available to all the stakeholders in a transparent and easy way.

 

  • Develop local institutions to improve sustainable groundwater management . This requires that higher-level authorities become receptive to the needs of local groups and encourage the development and support of strong institutional networks with water users and civic society.

 

  • Ensure that citizens recognize groundwater’s essential role in their community and the importance of its responsible use . This requires that science and applied technology serve to enhance education and outreach programs in order to broaden citizen understanding of the entire hydrologic system and its global importance to current and future generations.

 

Key References:

 

Alicante Declaration (final document), International Symposium on Groundwater Sustainability ( ISGWAS), Alicante, Spain, January 2006.

 

Custodio, E. & Llamas, M. R. (2003). Intensive use of groundwater: introductory considerations. In Llamas, M. R. & Custodio, E. (eds.). Intensive Use of Groundwater: Challenges and Opportunities. Swets & Zeitlinger BV, Lisse, The Netherlands, pp. 3–12.

 

International Assocation of Hydrogeologists, 2005: GROUNDWATER AND POVERTY REDUCTION IN AFRICA. Issues discussed at the London "GW8" meeting. http://www.iah.org/News/2005/051.html

 

J. M. Forne´s, A. de la Hera and M. R. Llamas / Water Policy not known (2005) 1–16. WP 5_004— 13/4/2005——144679

 

Llamas, M.R. and P. Martínez-Santos INTENSIVE GROUNDWATER USE: SILENT REVOLUTION AND POTENTIAL SOURCE OF SOCIAL CONFLICTS. ASCE Journal of Water Resources Planning and Management (Vol. 131, No. 4, July-August 2005)

 

Llamas, M.R. Water and Ethics: Use of Groundwater. UNESCO, 2004.

 

United Nations (2003). “Water for People, Water for Life”. UNESCO-WWAP. Paris, France. Chapter 4.

 

United Nations (2006). “Water: A Shared Responsibility”. UNESCO-WWAP. Paris, France.