The displacement of communities has in notable cases been a factor causing an outcry against hydropower projects. Dam construction unavoidably results in areas of land being flooded, with other areas being set aside for infrastructure development and catchment conservation areas. Population displacement has occurred on a range of scales from several families to tens of thousands of people.

In some cases the land has been the home of, and provided the spiritual, social and economic resource base for local communities. Of particular concern has been the involuntary displacement and resettlement of minority groups who have a specific attachment to land because of its cultural significance.  Land provides for material needs such as timber for housing, cooking and food supplies, as well as traditional medicinal remedies.  Loss of land can be associated with a loss of cultural identity and spiritual belonging.

In cases those affected may be vulnerable to social deprivation through being ill-equipped to deal with an unfamiliar way of living, and having few transferable and usable skills or support networks.  Women and children in particular may be vulnerable if they have no means of support.