Some 85% of Africa's water resources are comprised of large river basins that are shared between several countries. High rates of population growth accompanied by continued increases in the demand for water have resulted in several countries passing the point where the scarcity of water supplies effectively limits further development. Present population trends and patterns of water use suggest that more African countries will exceed the limits of their economically usable, land-based water resources before 2025. Normally, water allocation and distribution priorities within a country are aligned with national development objectives. While this may achieve national “water security” objectives, greater emphasis needs to be placed on regional efforts to ensure that the available water resources are used to derive sustainable long-term benefits for the peoples of Africa as a whole. Ideally, each country's water-resource management strategy needs to be aligned with that of its neighbors if peace and pr...

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Avoiding conflicts over africa's water resources

Hydropolitics in the developing world: a southern African perspective

Conceptual framework for the management of shared river basins; with special reference to the SADC and EU ☆

Although high-level attention has been drawn to the escalating world water problems, few changes are noticeable in terms of actual management of the water resource. Politicians continue to be misled by the apparent simplicity of water. The environment-oriented community tends to focus only on problems arising from man-induced side-effects, and most people tend to take water for granted. The double challenge of providing adequate water supplies and meeting increasing food requirements of expanding populations, in addition to already existing water management problems, requires special attention. In addition, the intensifying pollution of water systems will have to be dealt with. Considerable human adaptation to physical realities as well as ingenious action are needed.

There is a brief discussion of the risk of hydrocide, a condition of serious water-quality degradation where available water is no longer sufficient, or cannot be used for the purposes needed. However, the main focus of the paper is on water quantity issues, highlighting the confusion arising from different methods of assessing water scarcity. Levels of regional water scarcity predicaments are discussed in terms of distinct regional clusters. Attention is drawn to the limitations of dry climate regions to achieve food self sufficiency, and the emerging need in many areas to import food; related trade and price aspects are also discussed. A distinction is made between efficiency of use and efficiency of allocation.

The need for a global ethic regarding upstream–downstream water-sharing is stressed, especially in cases of consumptive (evaporative) use of water for cultivating crops, which may deplete river flows available to downstream users. In conclusion, four key concerns are highlighted that call for global consensus.

Towards water security: political determination and human adaptation crucial

The current interest in small reservoirs stems mainly from their utilization for domestic use, livestock watering, fishing and irrigation. Rarely were small reservoirs considered in the water resources system even though they are important in water resource planning and management. The main limitation being lack of knowledge on small reservoir capacities, for the methodologies used to quantify physical parameters of reservoirs are costly, time consuming and laborious. To address this challenge an attempt has been made in this study to estimate small reservoir storage capacities using remotely sensed surface areas. A field study on 12 small reservoirs was carried out in Mzingwane catchment in Limpopo River Basin; Zimbabwe. The depths of water accompanied with their coordinates were measured; from which area and capacity were calculated for each reservoir using geographical information system based on data acquired from the field and that from satellite images. The output data was compared and a linear regression analysis was carried out to establish a power relationship between surface area and storage capacity of small reservoirs. The Pearson correlation analysis at 95% confidence interval indicated that the variances of the two surface areas (field area and image area) were not significantly different ( p 2 ) and storage capacities of reservoirs (m 3 ), with 95% variation of the storage capacity being explained by surface areas. The relationship can be used as a tool in decision-making processes in integrated water resources planning and management in the river basin. The applicability of the relationship to other catchments requires further research as well as investigating the impacts of small reservoirs in water resources available in the river basin by carrying out a hydrological modelling of the catchment.

http://www.smallreservoirs.org/full/publications/reports/UZ-Sawunyama-MSc-thesis-0605.pdf

Estimation of small reservoir storage capacities in Limpopo River Basin using geographical information systems (GIS) and remotely sensed surface areas: Case of Mzingwane catchment

The theme of the book is sharing and managing water resources in Southern Africa (i.e. the 12 SADC member countries). The introduction gives an overview of the contents of each chapter. Key issues like water as a natural resource, its availability (as influenced by climatic factors), water uses and related problems (water stress, population growth, urbanisation and others), water shared within a river basin and between countries are addressed in the various chapters. The last chapters is devoted to management of water resources: Management principles, levels of management, involvement of the private sector and NGO's, the role of Agenda 21 of the United Nations Conference on the Environment and Development and the Helsinki Rules, and supply versus demand management. The text and the many coloured illustrations are supplemented by a useful glossary, bibliographical references and an index.

Piet Heyns

Papers

Sharing water in Southern Africa