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Alex de Sherbinin, IUCN-The World Conservation Union
Water is one of the most important of all natural resources. It is vital for all living organisms and major ecosystems, as well as for human health, food production, and economic development. Since the first civilizations arose in the Nile, Tigris, and Euphrates river basins, population growth and distribution have been intimately linked to the availability of freshwater. Today, nearly 40 percent of the worldís food supply is grown under irrigation, and a wide variety of industrial processes depend on water.
In the last half of this century, population growth and urbanization, together with changes in production and consumption, have placed unprecedented demands on water resources. Already, humans use more than one half of all accessible surface water runoff. This proportion is expected to increase to 70 percent by 2025, thereby reducing the quantity and quality of water available for aquatic ecosystems (Postel et al, 1996). These ecosystems are critical for a range of life-supporting functions ó including the cleaning and recycling of water itself.
More than 1 billion people today lack access to an adequate supply of safe water for household use. In 30 years, as many as 5.5 billion people may live in areas suffering from moderate to severe pressure on water resources, rendering the provision of safe water even more difficult (United Nations, 1997). In light of these trends, new approaches are urgently needed to manage water resources rationally and equitably. This entails efforts that will simultaneously address population dynamics, consumption patterns, and environmental conservation.
The water and population dynamics workshop at IUCNís World Conservation Congress in October 1996 examined these issues through presentations of regional and local case studies. The workshop brought together nine country teams representing diverse settings in Africa (Mali, Zambia, and Southern Africa), North Africa and the Middle East (Morocco and Jordan), South Asia (Bangladesh, India, and Pakistan), and Central America (Guatemala).
In one-and-a-half days of animated discussions, the teams and invited experts shared findings, explored ìlocal-to-globalî links, and examined the implications for improved policy and practice at the local, national, regional, and global levels. This introductory chapter distills the most important lessons learned and recommendations that emerged from the workshop.
Figure 1 provides a simplified diagram of the relationship between population dynamics and water resources. Population dynamics includes growth, distribution, migration, and other characteristics as shown. Population dynamics and water resources interact through human uses of water. For example, population growth leads to increased use of water for food production and household use, which, in turn, may exacerbate water shortages, food insecurity, and ultimately lead to economic and social crises. Conversely, naturally scarce water supplies, poor water quality, or uneven distribution of water resources may have adverse affects on the health and ultimately the growth and distribution of populations.
By far the most important demographic trend affecting water resources is population growth. The past two centuries have seen dramatic increases in world population, from one billion in 1800 to six billion at the close of the 20th century. More people and increasing consumption of food, consumer goods, and water for domestic use have created demands for clean freshwater that in many areas exceed natureís capacity to deliver through the hydrological cycle.
Figure 2 shows how people use freshwater in various parts of the world. Agricultural production accounts for an average of 69 percent of freshwater use worldwide, whereas industry uses 23 percent and households eight percent. The dependence of our food production systems on irrigation links freshwater with food security, and therefore with human nutrition and well-being.
Wastewater from the three major water use categoriesóagriculture, industry, and domestic useócontributes to water pollution. Agricultural fertilizers and pesticides, industrial effluents, and household wastewaters are often discharged with minimal treatment into surface water, and sometimes leach into underground aquifers. The contaminated water can be harmful to human health, leading to illness and even death.
Diarrheal diseases caused by unsafe drinking water are among the worldís greatest killers, contributing to the deaths of approximately three million children annually. Rapid urbanization and the lack of financial resources in the developing world have made it difficult for urban planners to respond to growing demands for sanitation infrastructure. The informal squatter settlements that surround many cities often lack piped water or any kind of waste disposal, making their residents prone to high rates of diarrheal and other diseases.
Large dams are a major part of the water-population equation. Dams are most often constructed for hydroelectricity, but they are also used to divert water for irrigation or domestic water supplies and to control flooding. Worldwide, there are some 40,000 large dams (those higher than 15 meters), most of which were built since 1950. A direct demographic impact of dam building has been the displacement of an estimated 30 million to 60 million people by reservoirs and irrigation works (McCully, 1996).
In some cases, dams can also attract migration, particularly if the water is channeled to arid areas or if industries relocate to make use of the resulting hydropower. Although dams contribute to increased agricultural production and economic growth, they can also adversely affect fisheries and aquatic ecosystems (e.g., rivers, floodplains, deltas, and mangroves). Disruptions in natural flood cycles can disproportionately affect the rural poor, whose livelihoods often depend on wetlands, fisheries, and flood-dependent agriculture. If aquatic ecosystems are altered, these rural residents may be forced to migrate to other areas.
Population growth and migration often lead to changes in land cover that can affect water resources. For instance, population growth contributes to increased demand for agricultural land, fuelwood and timber, resulting in deforestation. Forests act as water regulators by reducing water runoff and soil erosion and by helping replenish groundwater. They also release moisture into the atmosphere. Therefore, when forests are cut, the hydrological cycle is irrevocably altered unless regeneration occurs. Transformation of forests into pasture or croplands, especially in hilly areas, can lead to soil erosion, siltation of major water courses, flooding, and reductions in groundwater reserves.
Examples from the case studies illustrate key characteristics of the relationship between water and population dynamics:
It is reciprocal. Population dynamics affect water resources, but the relationship also works in the other direction. The India case study illustrates that in rural areas of Karnataka State, population growth has contributed to increased demands for water, expanded drilling of boreholes (tube wells), and resulting depletion of groundwater resources and water scarcity. At the same time, water scarcity has stimulated rapid outmigration to urban areas.
It is location-specific. The relationship is heavily influenced by the local climate, topography, vegetation, geology, and degree of human alteration of the landscape. Socioeconomic conditions, culture, institutional arrangements, and political factors also play major roles. Thus, there are no ìblanket prescriptionsî that will lead to more sustainable water-population relationships in, for example, Guatemalaís PetÈn region or the Kafue Flats of Zambia. Each has its particular mix of local attributes that makes it unique.
It transcends national boundaries. River basins do not always respect national boundaries. Use of water upstream, which is closely related to population dynamics and economic development, affects countries downstream. Likewise, downstream dams can block fish from migrating upstream. In the Ganges River Basin, deforestation and water abstraction in Nepal and India have reduced river flows and caused dry-season water shortages, salinization, and fishery depletion in Bangladesh. People living in the Ganges delta have been adversely affected by such changes.
It varies over time. In Mali, Morocco, and Jordan, cyclical patterns of drought greatly affect water resources from year to year. The population ìcarrying capacityî for these countries may be influenced more by the periodic droughts than by average annual rainfall over a 20 to 30 year period. In India and Bangladesh, water availability is dramatically affected by seasonal change, such as the onset of monsoon season. Populations must adapt to these changes accordingly.
A better understanding of the relationship between population dynamics and water resources is a first step toward designing policies that can make these relationships more sustainable. The characteristics described above point to four broad criteria for policies aimed at this goal. Policies should:
Policy recommendations that follow from these criteria are presented after the case study findings.
At the core of the water and population dynamics workshop were the country case studies. These studies provide lessons about how to create more sustainable water and population relationships. The case studies fall into three categories, as presented in this book: (1) human populations and water-dependent ecosystems; (2) supply and demand of freshwater in international river basins; and (3) community participation in water management. This section presents the major findings from the workshop, providing illustrations from the case studies.
Population stabilization is vital
Population stabilization reduces pressure on water resources and serves to ìbuy timeî for the establishment of improved water management, appropriate policies and institutional arrangements. Population growth can be slowed by taking action in related areas of population policy, reproductive health and family planning services, and improved educational and employment opportunities for women. In Morocco, for example, measures to improve access to family planning and raise the status of women have contributed to a reduction in the total fertility rate from seven to 3.1 average births per woman since 1970.
Community involvement is essential for effective water management
Because of the local nature of water-population relationships, involving communities is crucial to understanding local conditions, creating a sense of ownership, strengthening community capacity, and ensuring sustainable management of water resources. In the Pakistan case study, the community took charge of canal maintenance, which resulted in reduced water loss and more equitable distribution of irrigation waters. In the Morocco case study, by contrast, irrigation technologies and management structures set up at the national level were not well adapted to local socioeconomic conditions and the capacities of rural communities. As a result, the health and welfare of small holders were adversely affected. Appropriate technologies are needed that can be effectively maintained by local communities.
Access to water is a human rights issue
Water is often ìcapturedî by powerful economic interests, to the detriment of poor people. Access to water can be viewed as a human right, inasmuch as it is crucial for all aspects of human life. In the Pakistan case study, the local community took the irrigation department to human rights court for failing to guarantee sufficient water flows into the poorer ìtail areas,î and won the case. Collaborative management of water resources (i.e., sharing of responsibility between communities and state authorities) may be one mechanism for improving local access, especially in irrigation schemes.
Water resource issues benefit from a multidisciplinary approach
Water resource issues and population dynamics are not linked adequately in research, policy, and practice. Water resource management can benefit from a multidisciplinary team approach involving hydrologists, engineers, social scientists, and ecologists who, together with local stakeholders, collaborate in all phases of problem identification and analysis, policy dialogue and formulation, program design and implementation, enforcement, and monitoring and evaluation. In the India case study, a team of natural resource specialists and social scientists is working with the local community to manage scarce water resources through a watershed approach that includes soil conservation, reforestation, and restoration of traditional water storage systems.
Environmental conservation also meets human needs
Aquatic ecosystems support highly productive fisheries, plant communities, woodlands, and agropastoral systems. These wetlands also directly and indirectly support large human populations. For the millions of people worldwide who depend on or benefit from wetland resources, providing water for the environment and for people is one and the same. In the Mali case study, managers of the Manatali dam on the upper Senegal River are experimenting with controlled flooding to sustain the flood plain ecosystems and traditional agricultural systems while still meeting electricity generation and irrigation needs. However, in the cases of the Ganges delta (Bangladesh) and the Kafue Flats (Zambia), large dams have adversely affected aquatic ecosystems and the populations that depend on them.
Nonstructural solutions to water resource development and management can be effective
Engineering approaches to water resource development, such as dams, diversions, and pipelines, often come at great cost to the environment, and may not necessarily produce the expected economic returns or social benefits. Managing demand, pricing water to reflect its full cost, and using water-saving technologies and environmentally sensitive engineering may yield better results than simply increasing water supply. For example, over-application of large-scale engineering solutions for water supply and hydroelectricity in the Ganges, Indus, and Zambezi river basins has generated serious environmental and social impacts that might have been avoided had smaller scale, demand management been considered instead. In India, heavily subsidized electricity for water pumps owned by affluent land owners has contributed to depletion of the local aquifer. Full-cost electricity pricing and water-saving technologies would contribute to more sustainable and equitable water use.
Water management institutions can avert conflicts over water resources
Creating international or national water commissions to manage shared resources such as river basins can reduce the threat of conflict and promote equitable water sharing. Improved institutional capacity may involve formal legislation, international agreements, and treaties. For example, growing populations, commercial agriculture, electric utilities, and industries in several Southern African countries compete for the water resources of the Zambezi River basin. In the future, supplies may not be sufficient to meet domestic and commercial needs. A Water Sector has been created within the existing Southern African Development Community (SADC), and new initiatives are being carried out in conjunction with the Zambezi River Authority to establish a protocol on shared water courses and to promote integrated water resource management.
Urban population growth affects demand for water
As urban areas grow, the demand for water resources is likely to grow because urban populations, on average, use more water for domestic and industrial purposes than rural populations. The Jordan case study shows how the rapid growth of Amman and Zarqa, the countryís two major cities, has led to the unsustainable pumping of a major aquifer. This has reduced water availability for local farmers, and resulted in the desiccation of a wetland of international importance. On the other hand, urbanization can also present opportunities through economies of scale for more efficient and cost-effective water management.
Public education is necessary
Policymakers and the general public need to be educated about water resources and population dynamics, with an emphasis on making human activities sustainable with respect to water availability. For example, water resources in the Mayan Biosphere Reserve of Guatemala are naturally limited by the regionís geology. Rapid in-migration of settlers is creating additional water scarcity, and a lack of adequate water and sanitation infrastructure contribute to waterborne illness and other health problems. Educating settlers in water management and appropriate agricultural techniques could help to create a more sustainable relationship.
As these findings suggest, successful approaches to balancing the needs of different sectors, stakeholders, and the environment will often involve a combination of one or more of the following strategies:
In a final session, workshop participants examined lessons learned from the case studies in light of global trends in water resource use and management. They identified a series of generally applicable recommendations for improved policy and practice and topics that could benefit from further research. These are summarized below.
Water management policies
Education and communication
Water management policies have implications for social, agricultural, industrial, and environmental sectors, and therefore will involve a range of actors at local, regional, national, and international levels (see Box 1).
|Box 1. Actors in Formulating Water Management Policies|
The combination of actors and multisectoral policy activities proposed in the case studies and workshop discussions presents an enormous challenge. In many instances, inter-ministerial cooperation, communication between nongovernmental organizations (NGOs) and governments, and contact between interest groups in local communities is weak. Coordination of shared international water resources by an international water commission or strategy presents a special challenge: It requires integrating the interests of different states as well as different sectoral plans within and between countries.
Although it may not be possible to involve all actors, creating coalitions to develop practical policy responses will be an important part of any activity aimed at creating more sustainable relationships between population dynamics and water resources. Bringing together a variety of disciplines and approaches is a critical first step toward finding lasting solutions.
This wide range of recommendations demonstrates that there can be no single approach to balancing human needs, water supplies, and environmental conservation. Successful water resource management will rely on practical and participatory approaches, and on fostering an awareness of the complex links between population dynamics and water resources, both locally and globally.
Postel, S.L., Daily, G.C., and Ehrlich, P.R., 1996. ìHuman
Appropriation of Renewable Fresh Water.î Science 192: 785-788.
United Nations, 1997. Comprehensive Assessment of the Freshwater
Resources of the World. New York: United Nations Department of
Policy Coordination and Sustainable Development.
McCully, Patrick, 1996. Silenced Rivers: The Ecology and Politics of
Large Dams. London: Zed Books.
Postel, S.L., Daily, G.C., and Ehrlich, P.R., 1996. ìHuman Appropriation of Renewable Fresh Water.î Science 192: 785-788.
United Nations, 1997. Comprehensive Assessment of the Freshwater Resources of the World. New York: United Nations Department of Policy Coordination and Sustainable Development.
McCully, Patrick, 1996. Silenced Rivers: The Ecology and Politics of Large Dams. London: Zed Books.
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