Perspectives on the Salience and Magnitude of Dam Impacts for Hydro Development Scenarios in China

Following the principles and priorities outlined by the World Commission on Dams, managers are increasingly considering a greater variety of impacts in their decision making regarding dams. However, many challenges remain in evaluating the biophysical, socioeconomic and geopolitical impacts of dams, including the potential diversity of stakeholder perspectives on dam impacts. In this analysis, we surveyed representatives of non-governmental organisations, academics and hydropower and government officials in Yunnan Province, China, to better understand how stakeholder group views on the size (magnitude) and importance (salience) of dam impacts vary. We applied the technique defined by the Interdisciplinary Dam Assessment Model (IDAM) to simulate three dam development scenarios: dams in general, a single large dam and multiple small dams. We then surveyed the experts to measure their views on the magnitude and salience of 21 biophysical, geopolitical and socioeconomic impacts for the three scenarios. Survey results indicate differences in the perceived salience and magnitude of impacts across both expert groups and dam scenarios. Furthermore, surveys indicate that stakeholder perceptions changed as the information provided regarding dam impacts became more specific, suggesting that stakeholder evaluation may be influenced by quality of information. Finally, qualitative comments from the survey reflect some of the challenges of interdisciplinary dam assessment, including cross-disciplinary cooperation, data standardisation and weighting, and the distribution and potential mitigation of impacts. Given the complexity of data and perceptions around dam impacts, decision-support tools that integrate the objective magnitude and perceived salience of impacts are required urgently.