Ecological impacts of hydropower dams

Hydropower has been used as a clean energy source because it does not emit any greenhouse gases during electricity generation, thus helping to mitigate climate change. To maximise electricity production, large dams with large reservoirs have to be built, with profound environmental and social impacts. The hydrological changes caused by their construction can pose a significant threat to fish, aquatic plants and, in general, biodiversity downstream of the dam. Large reservoirs have even been shown to have transboundary impacts on ecology, agriculture and health due to the possibility of increased extreme rainfall events and humidity as a result of increased surface evaporation. In addition, it is estimated that more than 80 million people have been displaced by dam construction, leading to impoverishment and marginalisation of these communities.

Nº 80

Mekong Basin

some attempts made
past case
Region-1
Region-2
Region-3
Region-4
ongoing case
no attempts made

Ecological impacts of hydropower dams

Hydropower has been used as a clean energy source because it does not emit any greenhouse gases during electricity generation, thus helping to mitigate climate change. To maximise electricity production, large dams with large reservoirs have to be built, with profound environmental and social impacts. The hydrological changes caused by their construction can pose a significant threat to fish, aquatic plants and, in general, biodiversity downstream of the dam. Large reservoirs have even been shown to have transboundary impacts on ecology, agriculture and health due to the possibility of increased extreme rainfall events and humidity as a result of increased surface evaporation. In addition, it is estimated that more than 80 million people have been displaced by dam construction, leading to impoverishment and marginalisation of these communities.

The construction of hydropower dams in the Mekong Basin has far-reaching consequences for both the environment and the well-being of millions of people in China, Myanmar, Laos, Thailand, Cambodia and Vietnam. These dams have a significant impact on fish migration, sedimentation and hydrological patterns. They also affect communities along the river, including those up to 1000 km away, whose livelihoods depend heavily on the river’s resources. The dams pose a threat to food and economic security in these riparian areas.

Soukhaphon, A., Baird, I. G., & Hogan, Z. S. (2021). The impacts of hydropower dams in the mekong river basin: A review. In Water (Switzerland), 13 (3). MDPI AG. https://doi.org/10.3390/w13030265

Elagib, N. A., & Basheer, M. (2021). Would Africa’s largest hydropower dam have profound environmental impacts?. Environmental Science and Pollution Research, 28(7), 8936-8944.

Moran, E. F., Lopez, M. C., Moore, N., Müller, N., & Hyndman, D. W. (2018). Sustainable hydropower in the 21st century. Proceedings of the National Academy of Sciences, 115(47), 11891-11898