Dams have been a part of the economic development model of almost all nations of the world. At some stage of their development, most countries with water resources that can be economically exploited have built dams for energy, irrigation, and drinking water. Hydropower provides a non-polluting source of energy that may be generated in increasing amounts for the growing needs of growing populations. Once built, dams entail relatively low costs and maintenance compared to the costs associated with other forms of energy generation.
Dams however, are not built without a significant cost. In addition to substantial adverse impacts on the physical environment, they can disrupt the lives and lifestyles of people living in the reservoir area and of those dependent on this area. Even when thorough surveys of people adversely affected by dams are conducted, which is not always the case, it is not easy to recognize all the adverse impacts of dam construction on the affected people. Impacts that are not fully identified are difficult to fully mitigate. Poorly planned and implemented dams can devastate local socioeconomic systems without replacing them with comparable and acceptable alternative systems.
The adverse impacts of dam construction are compounded when the affected people belong to indigenous groups with a close or special relationship to the lands on which they live. The land likely to be submerged behind a dam could be supporting a distinct culture, with a language, and customs and traditions that are unique to the location. Resettlement of people from such locations is a much more difficult process, and can be successful only if the affected people themselves determine that acceptable alternatives exist, and those alternatives are actually offered to them.