Considering the increasing number of large dams worldwide as well as the lack of integrated studies on hydrology, agricultural systems and socio-economic effects in the downstream alluvial plains, research is required to fill this gap in a holistic framework. Ethiopia is an excellent case, since the country is engaged in an ambitious dam building plan. This project proposal exploits our longstanding expertise and network in the country and is elaborated in the framework of sustainability, focusing on both biophysical and socio-economic post-dam impacts. We will start assessing and mapping the environmental setting of the alluvial plains downstream of selected large dams, and use this as an input for the analysis of hydro(geomorpho)logy. These findings will be combined with measurements of channel incision to study the related water table fluctuations. In parallel to these activities by the physical geographers, the environmental economists will work on the assessment of agrarian changes in relation to migrations and land tenure changes. Combining the environmental knowledge and the understanding of agrarian changes, we will develop a model for post-dam hydrology and agricultural systems. In addition, the socio-economic impacts of dam building will be assessed and modelled. In the end, the agro-hydro and socio-economic models will be integrated into a holistic model allowing sustainability assessments of agricultural systems downstream of large dams in developing countries.