There are plans to build 428 new hydroelectric dams in the Amazon! How will this affect the rainforest ecosystem?

The Amazon rainforest is the largest rainforest ecosystem in the world, and it also houses the (arguably) longest river in the entire world. The river discharges more water than any other river, and this makes it a great spot for installing hydroelectric dams to harvest eco-friendly energy from the river.

There are currently plans to build 428 new hydroelectric dams in the Amazon rainforest in the future, while there are another 140 that are already being built or are operational. This means that we are looking at almost 600 hydroelectric dams in the future, which could severely affect the fragile rainforest ecosystem.

A satellite image of the Amazon River. Image by NASA, posted as Public Domain.

What are hydroelectric dams?

Hydroelectric dams are a pretty standard way of harvesting energy from rivers. They create big dams that can hold a large amount of water, where it will be stored until the price for electricity is high, or for when the consumers need it. At that point the dam will open, and the water will fall onto turbines, converting potential energy into electric energy that can be sold to consumers.

This type of energy is considered very ecological friendly, but this is only when looking at greenhouse gas emissions. These dams poses a direct threat to the surrounding biodiversity, and most dams flood huge areas around it, altering the ecosystem. The area below the dam will also be affected by having either very little water, or having a lot at the same time, which will make it difficult for plants and animals to live there.

This is the largest dam in the world, the Three Gorges Dam in China. It has also had very big impacts on the ecosystem in the area! Image by Flickr user Le Grand Portage, posted with the Creative Commons Attribution 2.0 Generic license.

The Amazon is a species hotspot

A species hotspot is where there are very many endemic species is a somewhat small area. The Amazon is one of the biggest hotspots, having thousands of unique species that are not found anywhere else on the planet.

This means that these dams could potentially kill entire species, and once they are gone from the Amazon, they are no where to be found ever again. Luckily most of the dams have some sort of ecological survey before being constructed, but no one knows for sure that these will be made properly, because these can easily be affected by corruption.

The problem with the Amazon hydroelectric dams

A recent paper published in Science goes into detail about exactly this, and their main concern is that even though there are ecological surveys, they are all conducted on an individual basis. Even if none of them have a big impact on the environment or the ecosystem, no one has checked into how big the impact will be once all 400+ dams have been built in the same ecosystem.

They believe that we need to look at these together, and studying the impact on each individual dam is not good enough. And I agree with them! There are so many vulnerable and fragile species in the Amazon rainforest, and we should take good care not to destroy their habitat.

Thanks for reading

About the author

Hi, I’m @valth! I live in Norway with my girlfriend, our newborn son, and our two dogs, one of which is seen wearing a bow tie in the profile picture!

I am very passionate about nature and biology, and have been studying ecology for a few years now. My passions are mostly within conservation biology, mycology (the studies of mushrooms), animal behavior and general microbiology. I really enjoy both the theoretical aspect, as well as the more practical aspect of biology, and I spend about as much time in front of biology textbooks as I do spend on finding and identifying plant, mushroom and animal species in the forests.