Astro Hacker News - Dam removals are bringing fish back across the northeastern United States

goda90 |next [-]

A rewilding organization bought some forest land, downstream from a dam, that used to get seasonal flooding before the dam was built and made an agreement with the dam operators to do artificial seasonal flooding via ditches they dug. The flooded forest has the effect of providing fish nurseries so hatchlings have a chance to hide and grow before the water recedes and they have to return to the river.

https://youtu.be/qcVMX32c0io

I think it's a testament that human activity and nature don't have to be all or nothing, but we need to consider and mitigate the impact of our actions and always leave space for nature.

worldsayshi |root |parent [-]

Exactly I don't get why we can't figure out and prioritize allowing fish to pass around the dams.

glenstein |next |previous [-]

More good news: after years of fighting, Brookfield Renewable agreed to sell four dams on the Kennebec River which will let Atlantic Salmon go back up river to their spawning territory. This just happened in 2025 and could be a bigger breakthrough than the massive alewife restoration that the article mentions.

My understanding is that the first few victories on this were very very hard but it seems to have created a precedent and a growing example emulated across the country.

https://themainemonitor.org/dams-sale-salmon-return-kennebec...

twright |next |previous [-]

This sounded familiar and then I realized I had read the same article a few weeks ago. This is some strange syndication I would propose changing the link to this one: https://biographic.com/death-by-a-thousand-dams/ it’s also way better layout and fewer ads.

m_herrlich |next |previous [-]

Good for the fish but as winters get warmer these dams will be useful to store rain that doesn't stay put in the mountains as winter snow. This might mean more summer droughts. Also a nice clean source of power. I would rather see fish ladders.

evolve2k |root |parent [-]

You actually want to restore the river to be more resilient as the earth warms, fish returning empowers many other parts of a river ecosystem.

Install dedicated water tanks to store water, evaporation rates are much less.

cyberax |root |parent [-]

> You actually want to restore the river to be more resilient as the earth warms, fish returning empowers many other parts of a river ecosystem.

Dams can make rivers more resilient.

cyberax |next |previous [-]

To add a bit of a negative: dam removal has far less success in salmon restoration. The Elwha dam removal resulted in no native salmon runs. All the salmon in Elwha are still raised in hatcheries (they have clipped fins, so that's easy to track).

The biggest success so far was in the Klamath River watershed.

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metalman |next |previous [-]

Small dams, hydropwer and fish can co exist, though there is a loss in 'efficiency' in extracting the free power embodyed in flowing water. Undershot wheels need to be relativly large and also leave room for fish to swim underneath them, but thats it, the wheel turns, the fish swim on by. The real problem are 'mid sized' hydropower turbines which cut of many large water sheds to fish migration, and I have been involved with water protectors in various ongoing attempts to remediate or remove varios dams and 'water control' aperatus, and the push back from entrenched intrests is rabid, anti everything but wealth and privlage, and the 'legal rights' to water sheds underpins many an unearned fortune, and perfectly illustrate the very ancient concept of Hydraulic Despotism.

krylonmae |next |previous [-]

That’s great until your land floods

notabotiswear |next |previous [-]

> Many NOOMBYs consider local dams indispensable ties to their community’s past; in Billerica, some town officials have objected to the demolition of the Talbot Mills Dam on the grounds that “it has long served as a symbol of the Industrial Revolution” that remains “unquestionably one of the major focal points in the area.”

I used to hate the "but what about historical site upstream?" argument often used against dams. The prioritisation of a few tombs and piles of stone over what would improve the lives of thousands to tens of millions living now. It's kinda ironic seeing the same asinine argument being used from the other side...

That said, reducing dams to just hydroelectric generation is probably going to skew the narrative to the wrong direction.

chihuahua |root |parent |next [-]

I think the fact that the same bogus argument is used both against dam building and against dam removal shows that it's bogus and not compelling. When someone is against something, they will use whatever argument they can concoct. Saying that something is historically significant seems to work great. As if history is some god that must be served no matter what.

jhide |root |parent |previous [-]

What do dams do besides hydroelectric generation?

ddxv |root |parent |next [-]

Dams create large bodies of water that change ecosystems and provide focal points for human communities. They certainly do more than just hydroelectric.

An example would be Lake Pillsbury in Northern California which the dam has not done hydroelectric for decades but the fight to prevent demolishing the dam has had plenty of local support.

lukeify |root |parent |next |previous [-]

Flood control and water storage for agriculture in drier summer months are the big ones.

hinkley |root |parent |previous [-]

The one Andrew Carnegie and his friends mismanaged and killed thousands of people with was for recreation.

darksaints |root |parent [-]

I think you probably meant Andrew Carnegie

kps |root |parent [-]

How to Wet Friends and Inundate People

threethirtytwo |next |previous [-]

But also less energy created by dams means energy is now likely offset by energy generated by greenhouse gases.

galago |root |parent |next [-]

A lot of the low hanging fruit is still dams that were made for non-hydroelectric, non-drinking, even non agriculural purposes. In the Northeast there are 19th century dams that originally powered mills before steam power. The barriers in some of these cases are just the cost of removing the dam, which can be substantial if it borders private property. Some of the flood control functionality is no longer necessary, because it can be migated and in some cases the land can just be bought out.

lukeify |root |parent |previous [-]

Most of these dams were either in disrepair, had geotechnical problems, or were sufficiently silted up they didn't generate much power anyway. A few dozen rooftop solar installations probably generate more power.

wiether |previous [-]

  > In Plymouth, Massachusetts, a former dam has been converted to a bridge that lets fish pass unimpeded beneath it

That's a hell of an ugly bridge!

They tried to make it look "natural" with the rock tiles but there's absolutely nothing natural about it.

A plain concrete bridge would have been less of an eyesore.

lukeify |root |parent |next [-]

In your opinion.

It's clearly being empathetic to the area's history, and it's taken from a vantage point that you won't often see anyway.

csallen |root |parent |next |previous [-]

I clicked the story just to see the very ugly bridge in question, and it turned out I think it's quite attractive

chihuahua |root |parent |previous [-]

Yeah, well, you know, that's just like, your opinion, man.

It's a bridge that looks like it's made from stone. It looks slightly different from other bridges. It's not bad. There are probably many eyesores in the surrounding towns that look much worse.