5 ms·

Removing old, obsolete dams restores life to creeks and streams

130 points by fludlight 6y ago

qchris 6y ago
If anyone's interested in rivers and dams, and some of history and influence they've had on the formation of the US (and vice versa), there's a great book called The Source: How Rivers Made America and America Remade Its Rivers. Not affiliated with the author in any way, but I picked it off a shelf last year and found it a really good read. This kind of thing brings up a bit of mixed feelings for me. On one hand, it's indisputable that damming rivers has a negative impact on the ecology of those watersheds. On the other hand, in an era of climate change, it seems like trying to hold on to as much freshwater capacity as possible also seems like a prudent idea, and I'm not sure what the best way to reconcile the two would be.
- 1bc29b36f623ba8 6y ago
  We do have the same issue here in Europe, albeit at a smaller scale. If the old dams can be re-purposed and brought back to use, then that would be a nice compromise. Some old dams and sluices are beyond repair, though. In those cases it's better to just restore the rivers as far as possible.
  - qchris 6y ago
    That's a fair point. In North America, one of the other things that we should probably consider is the American beaver, which can help with this sort of thing naturally, if they're allowed to. Their activity needs a little management to prevent them from disrupting existing settlements, but compared to effect they had before trappers started in on them, it seems like there's might be some room for a natural solution that checks both boxes to a degree. Edit: Just kidding, I hadn't realized that the Eurasian beaver had been reintroduced to so much of its original range. Looks like it's not just something for North America.
    - 1bc29b36f623ba8 6y ago
      Yeah, and here in Finland we have North American Beavers too, since someone decided to introduce them in the 30's. They have a somewhat devastating effect on the local forests...
      - fpoling 6y ago
        There is a saying in Russian “To kill the beaver, to save the tree”.
        bregma 6y ago
        In Canada the saying is "save a tree, eat a beaver". I'm not sure if it translates the same way, though.
- StanislavPetrov 6y ago
  >On the other hand, in an era of climate change, it seems like trying to hold on to as much freshwater capacity as possible also seems like a prudent idea, and I'm not sure what the best way to reconcile the two would be. Climate change doesn't mean warmer temperatures everywhere or a dearth of freshwater. The Hudson Valley area referred to here has plenty of fresh water, is projected to become wetter according to most climate change models, and has become wetter recently (significantly so the last few years). http://www.cnyweather.com/wxrainsummary.php http://www.cnyweather.com/wxrainsummary.php
  - fiblye 6y ago
    For regions that rely on snow accumulation on mountains in winter and melting into rivers during other seasons, they could be screwed. And plenty of regions heavily depend on that process.
  - qchris 6y ago
    You're right, and if I came across implying that was the case for this particular dam removal, I apologize for the miscommunication. On the other hand, the rate of dam removal in the United States has increased, and some of them (especially in the Western US) are in areas that don't experience the same frequency of rainfall, and where even existing reservoirs are often far below capacity. It was more of a general musing that a comment on this particular instance, which from the information in the article, seems like a positive step.
  - thaumaturgy 6y ago
    I forget the exact numbers, but something like 60% of California's freshwater supply is stored in the Sierra snowpack, and the current models are projecting that California will get more rain overall but vanishingly little snow. California politically tends to be completely opposed to building new reservoirs, and a large amount of seasonal northern California rainfall ultimately gets routed out to the San Francisco Bay through storm drainage. The other barrel of this particular footgun is that agriculture is still California's biggest industry and they require an absolutely enormous amount of water. This is already causing strain on state politics, because the central valley keeps demanding more water from northern California, which doesn't want to give up more of it, and southern California has just about drained the Colorado river, and restrictions on water rights are the single biggest driving force behind all the "State of Jefferson" signs you see in the rural northern counties. I love California but the water situation is about to bite them really hard. "About to", of course, still being a decade or two out, but there don't seem to be any reasonable solutions to this intractable situation on the horizon.
- acidburnNSA 6y ago
  That's not to mention using hydroelectric reservoirs from dams to store energy, which is absolutely fundamental in the mainstream "100% renewable" plans you may have heard of. For example, a lot of Green New Deal stuff largely draws from Mark Jacobsen (the Stanford prof who sued the scientists who published a critique of his plan in 2017). His plan depends on increasing hydroelectric capacity by something like 10x in the USA (albeit, he claims, just by adding turbines to existing dams, though that may be a challenge).
  - noad 6y ago
    It's really not though, renewables have already surpassed coal in the USA for the first time while hyrdo is treading water. The change already happened and all the concerns about peak load capacity and storage were largely mythical. Coal plants are racing to shut themselves down, the miners are all filing for bankruptcy. We didn't need to build dozens of new fission plants either. Another myth from the think tanks.
    - mehrdadn 6y ago
      > The change already happened and all the concerns about peak load capacity and storage were largely mythical Do you have a link to more on this? The story I recall was that we can't go fully renewable precisely because of storage issues.
    - eloff 6y ago
      If by surpassed you mean cheaper than building new coal, or even operating smaller coal plants, then yes. Coal generation is still 2.5x wind+solar [1]. Claiming that the intermittent nature of wind and solar is a non issue is a joke. The system can absorb small amounts of intermittent power, but the problem gets progressively worse as the percentage share of the total goes up. We do need, modern, cost effective nuclear, and pumped hydro, and large improvements in grid scale battery storage as well as more long distance transmission to even out the supply. [https://www.eia.gov/tools/faqs/faq.php?id=427&t=3 https://www.eia.gov/tools/faqs/faq.php?id=427&t=3]
      - 6y ago
acd 6y ago
A friends works as an ecologist and are a scientist at a university. Water Dams disrupt/destroy eco systems downstream. Hydro power is thus not fully green due to that. Water power has to be compared to The alternatives such as oil/coal. One should not view water power as fully “green” energy. Fish species are for example disrupted by water dams.
- generatorguy 6y ago
  I’ve worked on about 30 different run of river hydro electric projects over the last 15 years. Yes there is some environmental impact but the ones I have worked on have had a team of biologists and years of environmental studies and they would never result in a dead fish any more often that the river would have naturally by itself. If any habitat is destroyed they have to create new habitat such as spawning channels. They probably spend 10%-20% of the entire budget on environmental. These run of river plants don’t flood more than 1000m^2 area, use a weir instead of a dam, leave water in all sections of the river channel, and don’t cause unnatural changes in the river level at a rate greater than 1” per hour which is a very conservative rate compared to what the rivers of this size and nature naturally do by themselves when it rains or melts. I know you said Dams and not weirs and not run of river plants, and big dams have their issues, but not on the same scale as the oil industry.
  - bjelkeman-again 6y ago
    I have studies hydropower effects at my university programme, and a vocational aquaculture program, and as you say, there are definitely ways to lower the impact. In Sweden, all the major rivers except for two have large scale dams installed. Most of that was built between 1900 and 1950 and not much after 1970. Not much consideration for biodiversity or environmental impact was taken into account. At some point hydropower supplied 95% of Swedish electricity. Important during the country’s industrialisation. There is a nice reference list, including many English language reports at the end of this report from the Swedish Agency of Marine and Water Management. [1] I think they summarise it nicely by saying “Hydropower is one of the biggest impacts on the ecological status of a river. At the same time it is one of our most important energy sources.” [in Sweden] Sources: [1] https://www.havochvatten.se/hav/uppdrag--kontakt/publikationer/publikationer/2013-10-15-vattenkraftens-paverkan-pa-akvatiska-ekosystem.html https://www.havochvatten.se/hav/uppdrag--kontakt/publikation... https://sv.m.wikipedia.org/wiki/Vattenkraft_i_Sverige https://sv.m.wikipedia.org/wiki/Vattenkraft_i_Sverige
aaron695 6y ago
Humans are putting ongoing pressure to all environments. We need to stop with the bringing it back to how they were BS. It can't happen. Environments need energy and water to thrive amoungst other things. It's hard to see dams being bad overall. Yes it might harm certain things. But we need to start looking the bigger picture. Not little factoids like bringing back wolves. I find India's push on johads perhaps a little off topic but perhaps not. Be need to start keeping fresh water on or in the land. http://www.ecotippingpoints.org/our-stories/indepth/india-rajasthan-rainwater-harvest-restoration-groundwater-johad.html http://www.ecotippingpoints.org/our-stories/indepth/india-ra...
- pvaldes 6y ago
  I'm saying this in a polite tone. But sorry. Anybody that equals key species with "little factoids" don't understand a single thing about ecosystems. Would be like saying that the motor of a car is an optional part of the car. Wolves are boosters of biodiversity and change all around them.
markvdb 6y ago
See als https://en.wikipedia.org/wiki/Fish_ladder https://en.wikipedia.org/wiki/Fish_ladder and similar initiatives to allow migratory species to pass dams.

130 points by fludlight 6y ago

If anyone's interested in rivers and dams, and some of history and influence they've had on the formation of the US (and vice versa), there's a great book called The Source: How Rivers Made America and America Remade Its Rivers. Not affiliated with the author in any way, but I picked it off a shelf last year and found it a really good read. This kind of thing brings up a bit of mixed feelings for me. On one hand, it's indisputable that damming rivers has a negative impact on the ecology of those watersheds. On the other hand, in an era of climate change, it seems like trying to hold on to as much freshwater capacity as possible also seems like a prudent idea, and I'm not sure what the best way to reconcile the two would be.

1bc29b36f623ba8 6y ago
We do have the same issue here in Europe, albeit at a smaller scale. If the old dams can be re-purposed and brought back to use, then that would be a nice compromise. Some old dams and sluices are beyond repair, though. In those cases it's better to just restore the rivers as far as possible.
- qchris 6y ago
  That's a fair point. In North America, one of the other things that we should probably consider is the American beaver, which can help with this sort of thing naturally, if they're allowed to. Their activity needs a little management to prevent them from disrupting existing settlements, but compared to effect they had before trappers started in on them, it seems like there's might be some room for a natural solution that checks both boxes to a degree. Edit: Just kidding, I hadn't realized that the Eurasian beaver had been reintroduced to so much of its original range. Looks like it's not just something for North America.
  - 1bc29b36f623ba8 6y ago
    Yeah, and here in Finland we have North American Beavers too, since someone decided to introduce them in the 30's. They have a somewhat devastating effect on the local forests...
    - fpoling 6y ago
      There is a saying in Russian “To kill the beaver, to save the tree”.
      - bregma 6y ago
        In Canada the saying is "save a tree, eat a beaver". I'm not sure if it translates the same way, though.
StanislavPetrov 6y ago
>On the other hand, in an era of climate change, it seems like trying to hold on to as much freshwater capacity as possible also seems like a prudent idea, and I'm not sure what the best way to reconcile the two would be. Climate change doesn't mean warmer temperatures everywhere or a dearth of freshwater. The Hudson Valley area referred to here has plenty of fresh water, is projected to become wetter according to most climate change models, and has become wetter recently (significantly so the last few years). http://www.cnyweather.com/wxrainsummary.php http://www.cnyweather.com/wxrainsummary.php
- fiblye 6y ago
  For regions that rely on snow accumulation on mountains in winter and melting into rivers during other seasons, they could be screwed. And plenty of regions heavily depend on that process.
- qchris 6y ago
  You're right, and if I came across implying that was the case for this particular dam removal, I apologize for the miscommunication. On the other hand, the rate of dam removal in the United States has increased, and some of them (especially in the Western US) are in areas that don't experience the same frequency of rainfall, and where even existing reservoirs are often far below capacity. It was more of a general musing that a comment on this particular instance, which from the information in the article, seems like a positive step.
- thaumaturgy 6y ago
  I forget the exact numbers, but something like 60% of California's freshwater supply is stored in the Sierra snowpack, and the current models are projecting that California will get more rain overall but vanishingly little snow. California politically tends to be completely opposed to building new reservoirs, and a large amount of seasonal northern California rainfall ultimately gets routed out to the San Francisco Bay through storm drainage. The other barrel of this particular footgun is that agriculture is still California's biggest industry and they require an absolutely enormous amount of water. This is already causing strain on state politics, because the central valley keeps demanding more water from northern California, which doesn't want to give up more of it, and southern California has just about drained the Colorado river, and restrictions on water rights are the single biggest driving force behind all the "State of Jefferson" signs you see in the rural northern counties. I love California but the water situation is about to bite them really hard. "About to", of course, still being a decade or two out, but there don't seem to be any reasonable solutions to this intractable situation on the horizon.
acidburnNSA 6y ago
That's not to mention using hydroelectric reservoirs from dams to store energy, which is absolutely fundamental in the mainstream "100% renewable" plans you may have heard of. For example, a lot of Green New Deal stuff largely draws from Mark Jacobsen (the Stanford prof who sued the scientists who published a critique of his plan in 2017). His plan depends on increasing hydroelectric capacity by something like 10x in the USA (albeit, he claims, just by adding turbines to existing dams, though that may be a challenge).
- noad 6y ago
  It's really not though, renewables have already surpassed coal in the USA for the first time while hyrdo is treading water. The change already happened and all the concerns about peak load capacity and storage were largely mythical. Coal plants are racing to shut themselves down, the miners are all filing for bankruptcy. We didn't need to build dozens of new fission plants either. Another myth from the think tanks.
  - mehrdadn 6y ago
    > The change already happened and all the concerns about peak load capacity and storage were largely mythical Do you have a link to more on this? The story I recall was that we can't go fully renewable precisely because of storage issues.
  - eloff 6y ago
    If by surpassed you mean cheaper than building new coal, or even operating smaller coal plants, then yes. Coal generation is still 2.5x wind+solar [1]. Claiming that the intermittent nature of wind and solar is a non issue is a joke. The system can absorb small amounts of intermittent power, but the problem gets progressively worse as the percentage share of the total goes up. We do need, modern, cost effective nuclear, and pumped hydro, and large improvements in grid scale battery storage as well as more long distance transmission to even out the supply. [https://www.eia.gov/tools/faqs/faq.php?id=427&t=3 https://www.eia.gov/tools/faqs/faq.php?id=427&t=3]
    - 6y ago

acd 6y ago

A friends works as an ecologist and are a scientist at a university. Water Dams disrupt/destroy eco systems downstream. Hydro power is thus not fully green due to that. Water power has to be compared to The alternatives such as oil/coal. One should not view water power as fully “green” energy. Fish species are for example disrupted by water dams.

generatorguy 6y ago
I’ve worked on about 30 different run of river hydro electric projects over the last 15 years. Yes there is some environmental impact but the ones I have worked on have had a team of biologists and years of environmental studies and they would never result in a dead fish any more often that the river would have naturally by itself. If any habitat is destroyed they have to create new habitat such as spawning channels. They probably spend 10%-20% of the entire budget on environmental. These run of river plants don’t flood more than 1000m^2 area, use a weir instead of a dam, leave water in all sections of the river channel, and don’t cause unnatural changes in the river level at a rate greater than 1” per hour which is a very conservative rate compared to what the rivers of this size and nature naturally do by themselves when it rains or melts. I know you said Dams and not weirs and not run of river plants, and big dams have their issues, but not on the same scale as the oil industry.
- bjelkeman-again 6y ago
  I have studies hydropower effects at my university programme, and a vocational aquaculture program, and as you say, there are definitely ways to lower the impact. In Sweden, all the major rivers except for two have large scale dams installed. Most of that was built between 1900 and 1950 and not much after 1970. Not much consideration for biodiversity or environmental impact was taken into account. At some point hydropower supplied 95% of Swedish electricity. Important during the country’s industrialisation. There is a nice reference list, including many English language reports at the end of this report from the Swedish Agency of Marine and Water Management. [1] I think they summarise it nicely by saying “Hydropower is one of the biggest impacts on the ecological status of a river. At the same time it is one of our most important energy sources.” [in Sweden] Sources: [1] https://www.havochvatten.se/hav/uppdrag--kontakt/publikationer/publikationer/2013-10-15-vattenkraftens-paverkan-pa-akvatiska-ekosystem.html https://www.havochvatten.se/hav/uppdrag--kontakt/publikation... https://sv.m.wikipedia.org/wiki/Vattenkraft_i_Sverige https://sv.m.wikipedia.org/wiki/Vattenkraft_i_Sverige

aaron695 6y ago

Humans are putting ongoing pressure to all environments. We need to stop with the bringing it back to how they were BS. It can't happen. Environments need energy and water to thrive amoungst other things. It's hard to see dams being bad overall. Yes it might harm certain things. But we need to start looking the bigger picture. Not little factoids like bringing back wolves. I find India's push on johads perhaps a little off topic but perhaps not. Be need to start keeping fresh water on or in the land. http://www.ecotippingpoints.org/our-stories/indepth/india-rajasthan-rainwater-harvest-restoration-groundwater-johad.html http://www.ecotippingpoints.org/our-stories/indepth/india-ra...

pvaldes 6y ago
I'm saying this in a polite tone. But sorry. Anybody that equals key species with "little factoids" don't understand a single thing about ecosystems. Would be like saying that the motor of a car is an optional part of the car. Wolves are boosters of biodiversity and change all around them.

markvdb 6y ago

See als https://en.wikipedia.org/wiki/Fish_ladder https://en.wikipedia.org/wiki/Fish_ladder and similar initiatives to allow migratory species to pass dams.