Dams constitute a major interference with nature. They obstruct our planet’s lifelines. Not only do they destroy the immediate river, e.g. through backwater, river derivation or even drainage, they also commonly cause a secondary wave of destruction due to the construction of roads, high voltage power lines (frequently thousands of kilometre), etc.
The history of dams
In the 1980s and 1990s advocates for nature conservation and environmental protection worldwide focused on mega dams as a major issue of their concern. Wherever dams were projected, people stood up and protested against them (Hainburg, Nagymaros, Loire, Belo Monte…). With success: globally the construction of mega dams declined considerably and practically came to a standstill in the 1990s.
The concerns about the negative ramifications of dams were so many that, in 1997, the World Bank established the World Commission on Dams (WCD) in cooperation with conservation organisations and scientists. In its final report in 2000, the Commission concluded that dams are commonly designed and constructed in a way that causes too much harm to the natural environment and its people. As a solution, the WCD proposed – in the presence of Nelson Mandela – (non-binding) guidelines for the construction of dams. The World Bank stopped financing big dam projects. More information here: www.internationalrivers.org/campaigns/the-world-commission-on-dams
New dam construction surge
However, in the last 10 years the construction of dams has been booming more than ever before. Two factors are accountable for this boom:
1) Climate conservation: hydropower is commonly regarded as a “green” source of energy. In the course of the energy transition, ecological and social concerns about dams simply got washed away or were ignored. Due to “danger in delay” the World Bank resumed the financing of projects and ignored its own WCD guidelines. Even big international environmental associations, who vehemently opposed such projects in the 1980s and 1990s, keep quiet today.
2) China’s entry into the hydropower market: China is regarded as a global player in the hydropower market. There are 28,300 big dams within the country. However, China’s dam lobby is also active in other countries. Particularly in Africa and in other Asian countries, Chinese companies build dams with Chinese money.
Dams – the facts
Even though the talk in regards to renewable energies is often about solar and wind, 80 per cent of the renewable energy is actually generated by hydropower.
- there are 50,000 mega dams as well as millions of medium and small ones
- 40-80 million people have lost their homes due to flooding
- 500-750 million people suffer from the repercussions of dams (Survival International, 2011)
- it is unknown how many species have gone extinct due to dams – presumably tens of thousands
- 40% of stream water is held back by dams
- the amount of water that evaporates in reservoirs and impoundments equals 7% of the total water consumptions of humans worldwide
- 4% of all climate-jeopardising gases originate in dam reservoirs (most notably methane). Hence, dams contribute to global warming just as much as global air traffic.
- one third of all the river sediments (sand, gravel) is held back by dams and no longer reaches the oceans. This results in the erosion of deltas and estuaries such that storm surges can easily reach the hinterland (e.g. Mississippi Delta and New Orleans). The United Nations anticipate that by 2020 an additional 50 million people will be affected by floods.
By 2020, several thousand additional hydropower plants are expected to be constructed – devoid of compliance with international standards.
Currently, $ 100-120 billion are invested in the construction of new hydro-electric power plants annually. Even the last natural reserves are not spared from constructions: Mesopotamian and Amazonia, Indonesia, the Mekong region, Zambezi, Congo and Nile in Africa, and the Balkans in Europe. Every river is supposed to be dammed. In Amazonia 60 mega dams and 600 medium ones are projected. According to Brazilian scientists, some 1,000 fish species will go extinct if all these projected dams are actually being built. That is the equivalent of ten per cent of all freshwater fish species on Earth and more than the whole fish fauna of Europe and North America combined. And fish are not the only species affected.
570 dams are projected in the Balkan region, 1,500 in Turkey. The very high dam density in Austria does not prevent the planning of another 60 hydropower plants. This will destroy even the last remote areas in Austria. More information: www.fluessevollerleben.at
The projects become bigger and bigger: once constructed, Belo Monte is supposed to be the third biggest dam worldwide – if only for a brief period of time, because the projected Gran Inga Dam on the Congo River in Africa will be double the size of the Three Gorges Dam in China. The costs: US$ 80 billion. The World Bank announced to finance the project.