In the Midst of the Large Dam Controversy: Objectives, Criteria for Assessing Large Water Storages in the Developing World
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By some estimates, there are 47,000 large dams in the world. India had 4,635 "large dams" as per ICOLD definition. Only technical criteria such as height and storage volume are used for this classification. Large dam projects increasingly face opposition from the environmental lobby from around the world for their negative social and environmental impacts, while their role in development was largely ignored. There are three issues being investigated in this paper. First: the role of water in human development and economic growth, and the role of large storages. Second: what should be the best criterion for classifying dams in a way that they truly reflect the engineering, social and environmental challenges posed by dams? Three: what new objectives and criteria, and variables need to be incorporated in the cost-benefit analysis of dams so as to make it comprehensive? The authors have derived a new index called sustainable water use index (SWUI) from the composite water poverty index (WPI) developed by C. Sullivan (2002), to assess the water situation of a country. It includes four of the five sub-indices of WPI, to capture attributes such as access to and use of water, water environment and institutional capacities in water sector, each having equal weightage. The SWUI was calculated for 145 countries using data from Laurence et al. (2003). Analyses suggest that improving the water situation can drive its economic growth, through the human development route. It is further argued that building large storages would be crucial for improving the water situation of a country on a sustainable basis. The analysis based on data of 13,631 large dams across the world shows that the height of the dam does not have any bearing on the volume of water stored, a strong indicator of the safety hazard posed by dams. Further analysis using data of 9,878 large dams shows that the height has no bearing on the area of land submerged, again an indicator of the negative social and environmental effects. The regression using data on 156 large dams across India shows that normative relationship exists between the area of submergence and numbers of people displaced by dams. Therefore, a combination of criteria such as height, storage volume and the area under submergence needs to be considered for assessing the negative social and environmental consequences of dams. Further analysis shows that the available estimates of dam displacement could be "gross over-estimates" in the order of magnitude of eight. By illustrating the significant positive impact of large reservoir project on stabilizing national food prices, contributing clean energy, improving recharge to groundwater in semi arid and arid regions, and ensuring social security, the authors argue that economic viability of these projects should be assessed in relation these positive externalities they create. The authors estimate the benefit due to lower food prices attributed to large dams in India as Rs. 42.90 billion annually. At the same time, the negative externality effects of large dams should be built in the cost of dam projects to increase the accountability on the part of water development agencies in less developed countries, towards the communities, which are adversely affected by large dams.
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