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Imagine in countries like Vietnam/Cambodia/Laos where they dam up rivers for hydro so badly that it prevents downstream flows, wiping out the downstream natural ecology.

They also have wet/dry seasons, so for part of the year everything gets flooded, overruns the dams and wipes out whole villages.

Pretty much a complete eco disaster that few talk about.




> They also have wet/dry seasons, so for part of the year everything gets flooded, overruns the dams and wipes out whole villages.

This implies a degree of incompetence or corruption on the part of the dam designer and/or dam builder.

I won't say such things never happens, but it is what not being able to predict and design around a regular change of season implies.


> This implies a degree of incompetence or corruption on the part of the dam designer and/or dam builder.

Of course it does!

In Laos/Cambodia, the dams are mostly built by China in order to help them build their silk road to Sihanoukville (so that they can have an easier route to Africa). In Vietnam, it is just plain greed since they aren't in as much of a rush to help China.

Unless you ride a motorbike into the furthest remote areas of these countries, like I have, you wouldn't be the wiser. I've see it all.

Compare and contrast:

http://english.scio.gov.cn/m/beltandroad/2022-05/09/content_...

https://www.theguardian.com/cities/2018/jul/31/no-cambodia-l...


Dams are incredible for wet/dry seasons. They allow you to moderate the flow as you fill and release the revivor. It sounds like youre just describing incompetence.


> It sounds like youre just describing incompetence.

I am.


Is that for hydro or water storage though? Surely you want the flow for hydro.


This isn't about storage. They build hydro dams on running rivers.


That’s not how it works. After it fills up you have to let water out of the dammed reservoir at the same rate it flows in (on average) or else it overflows. The issues created are related to sediments and flow consistency. More info in the top response here: https://earthscience.stackexchange.com/questions/18287/do-da...


I don't appreciate the downvote because you aren't listening to what I'm saying.

When it rains, it floods. They (stupidly) build dams for rate of flow during low season (cause it isn't raining)... then the wet season comes and the dams all overflow. Poor construction practices doesn't help either. They also build dam after dam along the same river... I've see 10+ of these things... ends up being a chain of mess when the first one fails.

Just a bit of googling to give you examples:

"Dam design and greed may factor into flood devastation in Vietnam" https://www.refworld.org/docid/58f9ca0c13.html

https://tuoitrenews.vn/news/society/20231012/investigation-u...

https://www.voanews.com/a/vietnam-must-improve-flood-resilie...


Before the dam they'd have around the same amount of water, actually slightly less than that, as the reservoir loses water through evaporation.

Dams don't create water that wasn't there before.

It sounds like they're upset that the dam wasn't oversized to handle flood control in addition to hydropower.

That's a legitimate gripe with public investment and shortsightedness, but the damn aren't going to be making it worse (unless they're managed by morons).


> unless they're managed by morons

Apparently, you've never been to a country like Vietnam. It is a combination of poor education and greed.


A sudden inrush of water from a dam overtopping can be much worse than a consistent flow even if the absolute quantity is the same.




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