this post was submitted on 20 Jul 2025
47 points (100.0% liked)

No Stupid Questions

42629 readers
510 users here now

No such thing. Ask away!

!nostupidquestions is a community dedicated to being helpful and answering each others' questions on various topics.

The rules for posting and commenting, besides the rules defined here for lemmy.world, are as follows:

Rules (interactive)


Rule 1- All posts must be legitimate questions. All post titles must include a question.

All posts must be legitimate questions, and all post titles must include a question. Questions that are joke or trolling questions, memes, song lyrics as title, etc. are not allowed here. See Rule 6 for all exceptions.



Rule 2- Your question subject cannot be illegal or NSFW material.

Your question subject cannot be illegal or NSFW material. You will be warned first, banned second.



Rule 3- Do not seek mental, medical and professional help here.

Do not seek mental, medical and professional help here. Breaking this rule will not get you or your post removed, but it will put you at risk, and possibly in danger.



Rule 4- No self promotion or upvote-farming of any kind.

That's it.



Rule 5- No baiting or sealioning or promoting an agenda.

Questions which, instead of being of an innocuous nature, are specifically intended (based on reports and in the opinion of our crack moderation team) to bait users into ideological wars on charged political topics will be removed and the authors warned - or banned - depending on severity.



Rule 6- Regarding META posts and joke questions.

Provided it is about the community itself, you may post non-question posts using the [META] tag on your post title.

On fridays, you are allowed to post meme and troll questions, on the condition that it's in text format only, and conforms with our other rules. These posts MUST include the [NSQ Friday] tag in their title.

If you post a serious question on friday and are looking only for legitimate answers, then please include the [Serious] tag on your post. Irrelevant replies will then be removed by moderators.



Rule 7- You can't intentionally annoy, mock, or harass other members.

If you intentionally annoy, mock, harass, or discriminate against any individual member, you will be removed.

Likewise, if you are a member, sympathiser or a resemblant of a movement that is known to largely hate, mock, discriminate against, and/or want to take lives of a group of people, and you were provably vocal about your hate, then you will be banned on sight.



Rule 8- All comments should try to stay relevant to their parent content.



Rule 9- Reposts from other platforms are not allowed.

Let everyone have their own content.



Rule 10- Majority of bots aren't allowed to participate here. This includes using AI responses and summaries.



Credits

Our breathtaking icon was bestowed upon us by @Cevilia!

The greatest banner of all time: by @TheOneWithTheHair!

founded 2 years ago
MODERATORS
 

This is a stupid question mostly because I don’t know where to ask it. Also it seems like an obvious thing but I’ve never read any news mentioning ……

I was just reading an article going over recent flooding catastrophes and one thing that stood out was a dam adding to the high water by having to release water while the flooding was still happening.

But can’t dam operators see a storm forecast and start drinking, er draining, ahead of time? It’s seems like you could make a big difference in controlling flooding with just a day or two pregaming. That can’t be profound, so why does it never seem to be mentioned? It could be a significant factor on many floods, a critical use for NWS data, forecasts, warnings, so where are the news mentions?

top 11 comments
sorted by: hot top controversial new old
[–] FuglyDuck@lemmy.world 37 points 1 week ago (1 children)

short answer is yes, they do.

But like in texas, they didn't have enough warning and accurate enough information on how much to let out. you can blame that on trump's NWS/NOAA/Airforce. (the AF provides access to satellites operated by the military, and that's stopped for whatever reason.)

[–] AA5B@lemmy.world 12 points 1 week ago

This needs to be more public

But can’t dam operators see a storm forecast and start drinking, er draining, ahead of time?

Yes, they already do this. When rain is expected they lower the levels of the dam. Even just smaller rainfalls not quite flooding territory. But there's only so much water you can drain before it starts causing problems for the dam.

[–] thevoidzero@lemmy.world 19 points 1 week ago (1 children)

As others have mentioned they already do that to a degree they can with the uncertainty of forcast. It's called Forcast Informed Reservoir Operation (FIRO).

Important thing is that the forecast is uncertain farther you go in future, and smaller the area you're looking at. So the policies will have to take that into account, you can't simply empty your reservoir because if your forcast is wrong and you don't get enough rain, then you don't have the precious water anymore for dry season. But if you're wrong on the other side you get flood issue.

Satellite data and a lot of ground sensors are in place that help us better forcast the future storms along with improved computation and technology, but nothing is sure, and it might get worse with current situation. We already have problems because of previous funding cuts causing us to lose so many sensors.

Also a fun fact, we've had dams for so long that we don't know the natural flows for so many rivers so we can't calibrate our models well. Basically we built dams long before we started measuring the rivers. I've been meaning to publish this, but it's just stuck in a draft for almost a year now :(

[–] AA5B@lemmy.world 2 points 1 week ago (1 children)

Thanks for lots of good detail I’ve never seen befire

[–] thevoidzero@lemmy.world 4 points 1 week ago

Flood control is very close to my area of research. My research involves effect of dams on river water and I don't get to talk about it often, so it was fun. But I haven't actually worked on a dam control or made policies, so my work is more theoretical what ifs.

[–] litchralee@sh.itjust.works 10 points 1 week ago* (last edited 1 week ago) (1 children)

For an example of when a dam is teetering upon catastrophic failure, with operators stuck between a rock and a hard place, see the 2017 Oroville Dam crisis: https://en.wikipedia.org/wiki/Oroville_Dam_crisis

This was covered in a Plainly Difficult video on YouTube, as well as other channels like Practical Engineering (also on YT).

Essentially, in that situation, in anticipation of heavy rainfall, the operators were discharging water until they found the main spillway was becoming damaged (uncovering shoddy work from decades ago). But the amount of rain meant that using the never-tested emergency spillway might actually damage the dam foundations. So in the end, they had no choice but to use the main spillway, as the less worse of two awful choices.

Known only after the fact, 2017 was a particularly wet year in California, coming after years of drought conditions. So holding onto water within the reservoir wasn't imprudent. But a flaw in the main spillway, and lack of testing of the backup, made a bad situation worse, turning into a full blown emergency for the people living below the tallest dam in the USA.

[–] AA5B@lemmy.world 2 points 1 week ago

So they were relying on 47 year old charts, not updated for climate change, to guide their operations. That seems mighty suspicious

[–] givesomefucks@lemmy.world 8 points 1 week ago

Dams are set up in an area that a large amount of surrounding area naturally flows water into.

That's why dams are constantly letting water out, even when it hasn't rained.

So like, so X is the total amount of water before the dam overflows. You'd want to keep normal level at X - 25%. But if a storm is coming in they do pre-emptively open the floodgates and go down to X - 50% or whatever.

One of the big problems is these large storms last so long, days rather than hours. And even if they open the floodgates at the dam to help the lake, it makes it worse for people along the river it feeds into.

There's no simple solution, we already started doing all that decades ago. It's what was hiding the problem and why so many ignored it and it got so bad.

[–] Proprietary_Blend@lemmy.world -1 points 1 week ago (1 children)
[–] AA5B@lemmy.world 1 points 1 week ago

Cool, it’s on my queue. I don’t generally listen to podcasts but a bunch of their titles look interesting . Thanks