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Comment by cesarb | Hacker News Reader

> Hydroelectric dams typically cause even more damage when they fail, but I rarely see people worrying about whether using them for power will lead to war-time issues. https://en.wikipedia.org/wiki/Dam_failure

I believe the reason people worry less about hydroelectric dam failures is because, if they fail, they do not leave behind a contaminated area. Besides, it's just water; many people are used to floods caused by heavy rain, and the danger feels similar. In fact, hydroelectric dams can even help prevent (or contain) flooding, so it's the opposite of causing damage in that case. Of course, we're not talking about tailings dams, which do leave behind a trail of contamination when they fail.

(An interesting case is the failure of a tailings dam many years ago which flooded the Rio Doce with pollution, with that flood being mostly stopped by a hydroelectric dam downriver. The hydroelectric dam contained the damage instead of causing it.)

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> many people are used to floods caused by heavy rain, and the danger feels similar.

I don't know what "people feel", but the reality of a large dam that is blown up is more like a tsunami than a normal flood. If it hits a city, casualties can easily reach the 10s or 100s of thousands, instantly.

In a way, an upstream dam is a health hazard for anyone in the area that might be flooded that should be concerning at the same level as living in an area that has had some nuclear contamination.

For a busted dam to destroy a city, the city necessarily would have been built on land that was literally underwater until before the dam.

This isn’t common, to say the least.

This presumes the gigantic water mass in the dam would stay within the downstream river banks when released.

Water is not that polite...

https://en.wikipedia.org/wiki/List_of_natural_disasters_by_d...

This is not true.

Rivers are often dammed to create an artificial body of water that can be used for power generation. You are storing water from the river when it has a high flow rate, in order to be able to generate power when needed.

There is nothing that requires the area downstream from the dam to have been previously underwater.

> I believe the reason people worry less about hydroelectric dam failures is because, if they fail, they do not leave behind a contaminated area

They very easily could, especially if they wipe out a chemical plant, a dump site, or a number of other things.

Rio Doce was 43.7 million cubic metres and 18 deaths.

If someone blows up Kakhovka dam in Ukraine, it'll be about 18e9 m3, hundreds of thousands dead, wholesale destruction of everything downstream, shutdown of every energy plant that uses the resevoir for cooling, not to mention the hydroelectic station, and untold damage when winds blow the exposed sediment all over the steppe. Which is one of the most productive agricultural areas in the world.

So? This Kakhovka dam is a legitimate military target as the last remaining supply route for russian troops in/around Kherson.

> This Kakhovka dam is a legitimate military target

Not under the Geneva Convention "Works and installations containing dangerous forces, namely dams, dykes and nuclear electrical generating stations, shall not be made the object of attack, even where these objects are military objectives, if such attack may cause the release of dangerous forces and consequent severe losses among the civilian population." https://ihl-databases.icrc.org/customary-ihl/eng/docs/v2_rul...

And what would be the consequences should, say, Russia attack, say, the Kakhovka dam? Consequences, that is, for the attacker?

More sanctions? Direct military action against a major (or any) nuclear power? Condemnation and isolation for decades or longer?

My parent was saying that it was a legitimate target. I agree that if Russia decides to give up on the Geneva convention our options aren't great.

After thousands of war crimes identified, Russians have let crystal clear that they piss on the Geneva Convention.

They have violated yet the Geneva convention (and its laws that oblige to hummanitary treatment of civils in a war) countless times in a few months, and at a level rarely seen before.

You know, Geneva Convention can't divert a bomb.

Couple of 1000lb bombs misplaced, some confusion and you can't stop it, only watch. Has to be a very unfortunate hit, but shit happens.

Compared to that, the Zaporoshya nuclear plant will just shut down as designed even if hit in all its reactors; release maybe a week's worth radiation, completely harmless, and then sit still. And it's just upstream.

Think about it.

So-called 'green energy' bears so much more hazards.

Not a dam, but such a military strategy has already happened and was extremely foolish.

Intentionally breaching the dikes of the Yellow River killed nearly a million people, displaced several million more, and was a contributing factor to people turning towards the Chinese Communists and away from the KMT.

There's a dam in the US that's an even bigger issue if it were to go.

I guess there's also the argument that in case of dam failure, most people don't live to tell the tale, so it does not stay in the news for a long time.

In case of nuclear incident, actual death may be lower but the affected people will keep being concerned about health issues and complain (rightfuly so) about the necessary relocation, which makes for stronger staying power in the news.

Maybe look for the Vajont dam disaster, to see what could be

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