Dam problems - Social impacts

Dam good plans do not always make good practice

The socio-economic benefits of dams are numerous and in many places dams have undoubtedly contributed to economic development.

Many countries would look different today without hydroelectricity, irrigation, water supplies, flood control, and recreational activities around reservoirs. But the socio-economic impacts of dams should be taken into account too. As more and more dams are being built in populated areas of developing countries, the scale of the social and economic effects is growing.

Displacement of people
Estimates suggest that some 40 to 80 million people have been displaced by dams worldwide, yet mitigation, compensation and resettlement attempts are often inadequate. The Three Gorges Dam on the Yangtze River, due for completion in 2009, will displace 1.3 ~ 1.8 million people from 320 villages and 140 towns, and destroy very many ancient and historic sites.

Health
Dams impact on human health, both positively and negatively. Improved access to clean water is a major benefit of dams. However, the habitat created by dams is also perfect for disease-carriers such as mosquitoes and snails, meaning that diseases such as malaria and schistosomiasis often become endemic in dammed areas. When higher population densities in resettled communities go hand in hand with poor hygiene, tuberculosis, influenza and gastro-enteritis are often the result.

Damage to cultural heritage sites
In many places, large dams have impacted cultural heritage by the submergence and destruction of cultural resources such as shrines, buildings, artefacts, burial sites and sacred landscapes.

Endangered livelihoods
Finally, the disruption of natural ecosystems, particularly of floodplains, threatens the livelihoods of the millions of people who depend on fisheries, wetlands and regular deposits of sediment for agriculture.