In the Midst of the Large Dam Controversy: Objective and Criteria for Assessing Large Storages in the Developing World

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 two issues being investigated in this paper. First: 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? Second: 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 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 show