Water Resources Management in Ethiopia: Implications for the Nile ...

decelerating in the 1990s. The spike in dam construction, spurred by the desire to use water to increase economic development and improve human wellbeing and supported by increasing technical and financing abilities (Allan, 1999), was increasingly questioned for a number of reasons.

The decline in dam construction after the 1970s can be attributed to the exhaustion of the most suitable dam sites, increasing recognition and criticism of the social and environmental externalities attached to dams, and the growing value attached to the environment (World Commission on Dams, 2000; Gleick, 2004; Conca, 2006). By the end of the 20th century, many countries had witnessed a transformation in the way that water decisions were made. This change has accelerated in recent years because of some highly publicized water project controversies in which decisions were made by centralized government that adversely affected local populations. In addition to the well known debate over the Three Gorges Dam, which displaced between 1.3 and 1.9 million people in China, public protests took place over the construction of dams in India, Southern Africa, and elsewhere in the developing world (Gleick, 2006), and negative impacts have been reported for various dams in Africa (see chapters 9 and 13). In the U.S. and other developed countries, discussions of dam decommissioning are now common.

While the world is now much more aware of the negative impacts of large dams and irrigation schemes, their construction and use has had clear positive impacts on key aspects of economic development and global food security. For example, dam construction helped per capita water withdrawals keep pace with a rapidly rising global population (United Nations Educational, Scientific, and Cultural Organization, 2003). Further, dam construction helped provide water to expand irrigated areas, important not only for increasing food production with existing technologies but also because it allowed the widespread adoption of the high yield variety seeds of the 1960s Green Revolution. The result is that average food supply is above the per capita malnutrition threshold for the world as a whole, perhaps for the first time in history, and is at that threshold for the developing world (Food and Agriculture Organization, 2003).