Are reservoirs made by man

Questions and answers about dams

Often negative.

Many people have to leave their homes. Estimates go from 80 million and more. The weakest in society are often hit: indigenous people, fishermen and smallholders. They not only lose their livelihood, but often also their cultural roots. For many peoples, rivers have a spiritual meaning.

Tens of thousands of people are relocated for large projects. For the Three Gorges Dam in China, 1.4 million had to give way. Often the compensation is far too low. Fishermen and farmers are offered housing in cities where they have no source of income. Sometimes locals are simply chased away because they have no land titles.

The construction sites attract thousands of workers. Often the cities in the vicinity are not up to the onslaught. There is too little living space and social facilities such as hospitals. Crime and prostitution are increasing.

There is resistance to many dam projects. The police, the military and private security services sometimes use force against demonstrators. There are dead and injured.

People also suffer on the lower reaches of dammed rivers, hundreds or thousands of kilometers from dams. Estimates go from 500 to 750 million. Because the transport of sediments, which contribute to the fertility of the soils in river plains, is disrupted, agricultural yields decline. Soils can become too salty.

Scientists also attribute the shrinking river deltas to dams. As a result, mangroves are destroyed, agricultural land is lost and storm surges are favored, which endanger large areas. In Pakistan, for example, the Indus is so tightly regulated by 19 dams and 43 canals that very little water reaches the delta.

Dams contribute to the spread of disease. If there are no floods on the lower reaches, more mosquito larvae will survive.