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I am not sure that dam removal is the right decision for every dam, but it seems like there is a movement in that direction. A lot of what I hear locally when p

I am not sure that dam removal is the right decision for every dam, but it seems like there is a movement in that direction. A lot of what I hear locally when people push for dam removals seems like emotional activism rather than rational thinking. Losing hydroelectric power, facing renewed flooding seasons, losing easy navigation, etc. may not actually be an overall positive change. And the goals feel arbitrary - like when people say they want to “restore the environment”, I wonder why it makes sense to restore it to any particular particular point in time when all these rivers have changed over time. In other cases, where the goal is restoring fish populations, there are alternative methods of helping the fish population and a dam removal seems like a very expensive method with other risks.

pengaru 2y ago
AIUI these dams have a limited lifetime either way. Giving the natives and activists what they've been fighting for is a sort of consolation prize for something that was a cheaper option than proper repairs/maintenance. What I wonder is how long before new dams are being built in their place. Maybe after all the ailing bridges have been fixed, and there's another pile of federal money desperate for "green infrastructure" projects to be spent on...
- WorldMaker 2y ago
  Since the time that many of those dams that are worth demolishing for poor repairs/maintenance the federal government has also made it harder to get permits to build new dams. They require more environmental studies up front. They require more study of downstream effects. Things like salmon, which are very sensitive to changes in river conditions, now have to be taken into effect earlier in planning stages and it is a growing requirement that any river to be dammed that include salmon hatcheries now has to plan for sub-projects like salmon runs (or with certain exceptions salmon cannons).
hooverd 2y ago
I'd say the stated goal of improving the river ecosystem was a success.
- Gormo 2y ago
  What does "improving the river ecosystem" mean?
  - 83 2y ago
    This is largely addressed by the article. Improved biodiversity (more fish, more native vegetation and the bugs/wildlife that go with it) as well as improvement of the water itself like the elimination of dangerous algae blooms. From the article: The dams also had a severe impact on water temperature and quality – growth of toxic algae behind two of the dams resulted in health warnings against water contact. Also from the article: "where we've seeded is green, we're seeing flowering plants teeming with life. I counted eight different butterflies in the areas we hand-seeded. There's moths, hoverflies, bees, birds. It's been a really exciting first year."
pkaye 2y ago
There are many small dams that are at end of life and no longer worth replacing. The company that owned this dam was in favor of removing it.
marssaxman 2y ago
Many of the primitive hydropower dams built a century or more ago have a production capacity which is negligible by modern standards. The two dams removed from the Elwha river here in Washington were the lowest and third-lowest producers in the state; the capacity lost by decommissioning them was utterly overwhelmed by the new wind and solar capacity added in a single year. I don't recall precisely how much power the Klamath dams generated, but when I looked it up, though the numbers were larger, the overall situation was similar: the hydro capacity California lost was inconsequential given the growth in other renewable sources. It's not so much that the river needs to be restored to a particular point in time as that the river needs to actually be a river and not a lake, if it is to support a river-dependent ecosystem. Water temperature, flow rate, presence of shallows, shade, woody debris, and so forth are all environmental elements which have a large effect on the viability of a habitat for keystone species like salmon. You can't just fake it with fish ladders.
lamp_book 2y ago
You should check out Cadillac Desert. Many dams in the US were built with no rationale beyond capturing federal infrastructure funds by local politicians and resume driven development on the part of the US Army Corps of Engineers and the Bureau of Land Reclamation.
- mechagodzilla 2y ago
  It was a pretty eye-opening book. I think most people assume individual dams provide far more value than they often do in practice.
_yb2s 2y ago
I agree- but I don't think anyone is saying it is right for every dam. However, a lot of dams probably just aren't worth it on net when you do consider all of the factors, and massively decreasing prices of alternatives. There aren't really solutions for migratory fish that support the kind of populations the rivers supported without dams... especially the ancient and poorly designed dams already in place. For example historical estimates are that ~16 million salmon migrated in the Columbia river despite being a major food source for a large number of Native Americans over a massive area. Nowadays, with every practical measure in place, lot of hatcheries, and almost no fishing those numbers are only up to ~1 million. Obviously we're probably not going to return to ~16 million, but the impacts of not doing so are widespread and far lasting- for example salmon coming upstream are historically a major source of nitrogen for the forests in the northwest, and without them long term, the forests will be something substantially different and diminished - with far reaching impacts on the entire ecosystem and many other resources of value to humans[1]. Gradual loss of the deep soil and peat from those forests also causes flooding and drought as the soil no longer stores large amounts of moisture that is slowly released over the dry season- e.g. ecological changes from dams may in the long term actually make flooding and drought more severe rather than less. [1] "total annual growth per unit forest area (m2·ha−1·yr−1) was more than three times higher at spawning sites relative to reference sites" https://esajournals.onlinelibrary.wiley.com/doi/full/10.1890/0012-9658%282001%29082%5B2403%3AEOSDNO%5D2.0.CO%3B2 https://esajournals.onlinelibrary.wiley.com/doi/full/10.1890...
bsder 2y ago
> A lot of what I hear locally when people push for dam removals seems like emotional activism rather than rational thinking. It's more maintenance and liability transfer, but environmentalism gets more clicks. A lot of these dams are small, old, and poorly designed even by the standards of the day. They provide a negligible amount of electricity by today's standards. And, if they fail, they'll do a lot of damage. Removing them isn't really up for much debate. The question is always "Who pays for the removal?"

pengaru 2y ago

AIUI these dams have a limited lifetime either way. Giving the natives and activists what they've been fighting for is a sort of consolation prize for something that was a cheaper option than proper repairs/maintenance. What I wonder is how long before new dams are being built in their place. Maybe after all the ailing bridges have been fixed, and there's another pile of federal money desperate for "green infrastructure" projects to be spent on...

WorldMaker 2y ago
Since the time that many of those dams that are worth demolishing for poor repairs/maintenance the federal government has also made it harder to get permits to build new dams. They require more environmental studies up front. They require more study of downstream effects. Things like salmon, which are very sensitive to changes in river conditions, now have to be taken into effect earlier in planning stages and it is a growing requirement that any river to be dammed that include salmon hatcheries now has to plan for sub-projects like salmon runs (or with certain exceptions salmon cannons).

hooverd 2y ago

I'd say the stated goal of improving the river ecosystem was a success.

Gormo 2y ago
What does "improving the river ecosystem" mean?
- 83 2y ago
  This is largely addressed by the article. Improved biodiversity (more fish, more native vegetation and the bugs/wildlife that go with it) as well as improvement of the water itself like the elimination of dangerous algae blooms. From the article: The dams also had a severe impact on water temperature and quality – growth of toxic algae behind two of the dams resulted in health warnings against water contact. Also from the article: "where we've seeded is green, we're seeing flowering plants teeming with life. I counted eight different butterflies in the areas we hand-seeded. There's moths, hoverflies, bees, birds. It's been a really exciting first year."

pkaye 2y ago

There are many small dams that are at end of life and no longer worth replacing. The company that owned this dam was in favor of removing it.

marssaxman 2y ago

Many of the primitive hydropower dams built a century or more ago have a production capacity which is negligible by modern standards. The two dams removed from the Elwha river here in Washington were the lowest and third-lowest producers in the state; the capacity lost by decommissioning them was utterly overwhelmed by the new wind and solar capacity added in a single year. I don't recall precisely how much power the Klamath dams generated, but when I looked it up, though the numbers were larger, the overall situation was similar: the hydro capacity California lost was inconsequential given the growth in other renewable sources. It's not so much that the river needs to be restored to a particular point in time as that the river needs to actually be a river and not a lake, if it is to support a river-dependent ecosystem. Water temperature, flow rate, presence of shallows, shade, woody debris, and so forth are all environmental elements which have a large effect on the viability of a habitat for keystone species like salmon. You can't just fake it with fish ladders.

lamp_book 2y ago

You should check out Cadillac Desert. Many dams in the US were built with no rationale beyond capturing federal infrastructure funds by local politicians and resume driven development on the part of the US Army Corps of Engineers and the Bureau of Land Reclamation.

mechagodzilla 2y ago
It was a pretty eye-opening book. I think most people assume individual dams provide far more value than they often do in practice.

_yb2s 2y ago

I agree- but I don't think anyone is saying it is right for every dam. However, a lot of dams probably just aren't worth it on net when you do consider all of the factors, and massively decreasing prices of alternatives. There aren't really solutions for migratory fish that support the kind of populations the rivers supported without dams... especially the ancient and poorly designed dams already in place. For example historical estimates are that ~16 million salmon migrated in the Columbia river despite being a major food source for a large number of Native Americans over a massive area. Nowadays, with every practical measure in place, lot of hatcheries, and almost no fishing those numbers are only up to ~1 million. Obviously we're probably not going to return to ~16 million, but the impacts of not doing so are widespread and far lasting- for example salmon coming upstream are historically a major source of nitrogen for the forests in the northwest, and without them long term, the forests will be something substantially different and diminished - with far reaching impacts on the entire ecosystem and many other resources of value to humans[1]. Gradual loss of the deep soil and peat from those forests also causes flooding and drought as the soil no longer stores large amounts of moisture that is slowly released over the dry season- e.g. ecological changes from dams may in the long term actually make flooding and drought more severe rather than less. [1] "total annual growth per unit forest area (m2·ha−1·yr−1) was more than three times higher at spawning sites relative to reference sites" https://esajournals.onlinelibrary.wiley.com/doi/full/10.1890/0012-9658%282001%29082%5B2403%3AEOSDNO%5D2.0.CO%3B2 https://esajournals.onlinelibrary.wiley.com/doi/full/10.1890...

bsder 2y ago

> A lot of what I hear locally when people push for dam removals seems like emotional activism rather than rational thinking. It's more maintenance and liability transfer, but environmentalism gets more clicks. A lot of these dams are small, old, and poorly designed even by the standards of the day. They provide a negligible amount of electricity by today's standards. And, if they fail, they'll do a lot of damage. Removing them isn't really up for much debate. The question is always "Who pays for the removal?"