4 ms·

On the one hand this is great news. On the other, (hydroelectric) dams appear to me to be very invasive, with high costs for the environments and the population

On the one hand this is great news. On the other, (hydroelectric) dams appear to me to be very invasive, with high costs for the environments and the populations around them.

TomK32 9y ago
They are but a lot of the old dams, fallen into disuse long ago are being removed. A few new big ones are a nuisance but there's thousands upon thousands that hinder small rivers Here's a map, though nothing on Portugal, the Spanish map is quite impressive https://damremoval.eu https://damremoval.eu
- asymmetric 9y ago
  Amazing resource, thank you. To quote[0] on the environmental impacts alone: - Dams impact every aspect of healthy rivers. - Dams lead to loss of river habitat as the river is transferred into impoundments, (impoundments or reservoirs are not lakes). - Dams lead to loss of river habitat as the hydro and sediments dynamics in the river are severely modified. This impact can reach hundreds of kilometres down the river and affect deltas. - Dams seriously impede the migrations of fish and this leads directly to the decline and even local extinction of many species. If we want to keep certain fish species in Europe, like eel, sturgeon, salmon, it is of great importance to restore connectivity from sea to source. However, we tend to focus on fish in relation to dam impacts; but many other species living in the water and on land depend on natural rivers and would benefit from free- flowing rivers. - Modification of water dynamics do also alter habitats and thereby favouring different, often invasive species [0]: https://damremoval.eu/about/ https://damremoval.eu/about/
  - icebraining 9y ago
    Yes. In fact, the biggest dam in Portugal (Alqueva) has probably had a negative impact on multiple species of land carnivores, including endangered species like the Iberian lynx, due to its large extension of flooded land.
  - mping 9y ago
    Damned if you do, damned if you don't? Pun intended.
carlob 9y ago
Yeah, hydro should really not be considered renewable, not just because it's invasive, but also because it's not renewable: dams fill up with silt and have to be either abandoned, removed or desilted. Go read Cadillac Desert, it's been written a few decades ago, but it's a real eye opener on the history of water management in the (west) US.
- cesarb 9y ago
  > but also because it's not renewable: dams fill up with silt and have to be either abandoned, removed or desilted If you consider wear and tear on the infrastructure, then nothing is renewable. Wind turbines don't last forever, solar panels slowly produce less power, etc.
  - carlob 9y ago
    Yeah but there are only so many places where you can build a dam. And also the usual equation renewable = safe for the environment and humans doesn't quite work: as many other commenters have pointed out dams are very bad for the environment, and they sometimes kill a bunch of people too. https://en.wikipedia.org/wiki/Vajont_Dam https://en.wikipedia.org/wiki/Vajont_Dam
    - sergiosgc 9y ago
      Calling a dam destructive to the environment is way too loaded. Dams do destroy ecosystems, but they create new ones. It's not like they tear down tropical forest to build a parking lot. If the destruction affects endangered species, I may land on the no-dam side. Otherwise, it's a preference question. Do you prefer changing an healthy ecosystem into another healthy ecosystem or do you prefer building a thermal/nuclear power plant? I prefer the renewable one.

On the one hand this is great news. On the other, (hydroelectric) dams appear to me to be very invasive, with high costs for the environments and the populations around them.

TomK32 9y ago

They are but a lot of the old dams, fallen into disuse long ago are being removed. A few new big ones are a nuisance but there's thousands upon thousands that hinder small rivers Here's a map, though nothing on Portugal, the Spanish map is quite impressive https://damremoval.eu https://damremoval.eu

asymmetric 9y ago
Amazing resource, thank you. To quote[0] on the environmental impacts alone: - Dams impact every aspect of healthy rivers. - Dams lead to loss of river habitat as the river is transferred into impoundments, (impoundments or reservoirs are not lakes). - Dams lead to loss of river habitat as the hydro and sediments dynamics in the river are severely modified. This impact can reach hundreds of kilometres down the river and affect deltas. - Dams seriously impede the migrations of fish and this leads directly to the decline and even local extinction of many species. If we want to keep certain fish species in Europe, like eel, sturgeon, salmon, it is of great importance to restore connectivity from sea to source. However, we tend to focus on fish in relation to dam impacts; but many other species living in the water and on land depend on natural rivers and would benefit from free- flowing rivers. - Modification of water dynamics do also alter habitats and thereby favouring different, often invasive species [0]: https://damremoval.eu/about/ https://damremoval.eu/about/
- icebraining 9y ago
  Yes. In fact, the biggest dam in Portugal (Alqueva) has probably had a negative impact on multiple species of land carnivores, including endangered species like the Iberian lynx, due to its large extension of flooded land.
- mping 9y ago
  Damned if you do, damned if you don't? Pun intended.

carlob 9y ago

Yeah, hydro should really not be considered renewable, not just because it's invasive, but also because it's not renewable: dams fill up with silt and have to be either abandoned, removed or desilted. Go read Cadillac Desert, it's been written a few decades ago, but it's a real eye opener on the history of water management in the (west) US.

cesarb 9y ago
> but also because it's not renewable: dams fill up with silt and have to be either abandoned, removed or desilted If you consider wear and tear on the infrastructure, then nothing is renewable. Wind turbines don't last forever, solar panels slowly produce less power, etc.
- carlob 9y ago
  Yeah but there are only so many places where you can build a dam. And also the usual equation renewable = safe for the environment and humans doesn't quite work: as many other commenters have pointed out dams are very bad for the environment, and they sometimes kill a bunch of people too. https://en.wikipedia.org/wiki/Vajont_Dam https://en.wikipedia.org/wiki/Vajont_Dam
  - sergiosgc 9y ago
    Calling a dam destructive to the environment is way too loaded. Dams do destroy ecosystems, but they create new ones. It's not like they tear down tropical forest to build a parking lot. If the destruction affects endangered species, I may land on the no-dam side. Otherwise, it's a preference question. Do you prefer changing an healthy ecosystem into another healthy ecosystem or do you prefer building a thermal/nuclear power plant? I prefer the renewable one.