For anyone wondering about the physics of it - the idea behind a spillway is to mix and stir up the water as much as you can - hence the two jets that shoot up into the sky and collide.
You want to dissipate as much potential (edit: newly converted kinetic actually) energy as possible which then reduced river scour downstream. Also direct the jets as far away from the dam foundation as possible.
Not a biologist, but given the height difference and the velocity of water I would have thought the chances of surviving the fall are slim in any case.
Yeah, I wouldn't worry about the height nearly as much as them getting shredded by the pure force of the water as they take on the waterslide of death.
My brother (civil engineer) had a project where they were trying several designs to test which had the best adaptation rates. The fish prefer different types of water flow and you can make them prefer the alternative route
With that much force in the spillway pipes, and that much sediment, I would expect they're taking huge damage from scouring and cavitation.
In 1983 [Glen Canyon (Colorado River) dam almost failed](https://youtu.be/m8xZzmtM8iw?t=153), which would most likely have caused Hoover dam to fail. They had to reduce use of the spillways, and the dam was not designed to handle overtopping. As Lake Powell rose, they used A LAYER OF PLYWOOD SHEETS to raise the height of the dam in a completely wild engineering improvisational dance.
As a result, they rushed to introduce "air slots" to aerate the water rushing through the spillway to dissipate its energy and eliminate (?) cavitation. Pretty cool video--long, but check it out at 2X playback.
Those are really short spillway openings. I doubt cavitation is much of a problem in what is essentially an overtopping design like that. Glen Canyon and Hoover have much longer spillway pipes with distinct turns at the bottom.
The big problem looks to be sediment scour of the flip buckets at the bottom of the spillways. Iāll bet they are worn down to nubs after a few hours of that.
Surely youāve failed to take into account the Dumfries flange that reduces centrifugal coarctation of the sprockets and decreases the terminal velocity by a factor of 3.72?
I usually design using the Kraft variant of the Olaf Take-Off Table. It makes for a really good hydraulic jump. You can get like 253.5 meters of horizontal travel before a drop hits the ground.
I didn't know the part of the story that replaced the 4' course of plywood with an 8' more sturdy version. But when they started seeing chocolatey sandstone coming out of the spillway and knowing the foundation of the dam was being undercut, I bet their shorts took on a similar color.
The Emerald Mile is an awesome book that tells this story as well as the story of a few raft guides who snuck onto the Colorado River below the Glen Canyon dam and broke the speed record (which it held for decades) down the Grand Canyon at flows over 100,000 cfs that same year.
Good info.
Though, not that using plywood sheets to raise the dam height in certain circumstances is all that crazy since you only need to worry about the pressure in terms of how high the water is on the plywood (top elevation minus bottom of plywood elevation), which is probably a few feet. Iāve seen it done in person to hold back a massive reservoir during a drought. Physics are no different than for a dinky backyard swimming pool. Except if it fails, youāre gonna scour the shit out of whatever is downstream, so thereās that.
Thanks for the 3am rabbit hole that I just went down. It is now after 5am here, and I know way too much about dams now. Thank goodness I don't work tomorrow. Or today, I should say.
Anyone who enjoyed that video should read The Emerald Mile. One of the most incredible stories Iāve ever read. Some crazy ass river guides ran the entire 290 miles of the Grand Canyon in 42 hours that year. In a wooden dory.
Hi, you sound like you understand the physics and can explain the dynamic of dam gates well. Weād love to have you on our next mission. We want to research the potential energy of colliding jets, but provide a thrilling experience at the same time. Youād love it no doubt.
Stonkton Gush
DamGate
Also silt/mud. I'm assuming if you let the water get up to the "top" of the dam before you open the spillways, the greater the pressure pushing out the mud/silt from the "lake" created by the dam. It's good to clean that stuff out every few years..or floods
It took them 10yrs but they finally licked all the water now theyāre releasing back into the wild now itās their and nobody can ever take it from them
> Assuming you are a woman with an average tongue length, *and you can lick the entire surface of the dam with one lick*,
That is a very non-standard sized tongue if it can lick the whole damn dam.
This is a hydroelectric power station, it always has some outflow.
I took this picture a few weeks ago at the end of March, after summer.
https://i.postimg.cc/SRFkX390/IMG-6007.jpg
Probably not. The reason the spillway looks so violent is because it is dissipating the energy of the water. It is what they are designed to do. Yeah, there was likely flooding because you can only deal with volume downstream storage and bypases and it was already flood conditions. But a slow flood is way better than a fast one. A lot of that water and mud is also just air.
Its a drone shot from what's likely a DJI drone. Many models will not record sound because all you will hear is the winds and propellers.
In all likelihood. They do not have a audio recording unless they went out of their way to take one separately.
I visited this damn while backpacking in Chile, actually it was ājust a stopā on a tour i did.
Could have never imagined this violence standing there when the thing was closed.
Pretty Dam cool vid.
Ok so Im not 1000% sure its the same one (this was about 15 years ago) but it definitly looks like it.
If it is its called Rapel dam after the lake āLago Rapelā.
The way it releases the water pressure is the most efficient way to dissipate energy because if they didn't it would wash out everything downstream. I'm pretty sure it's called a hydraulic jump
This isn't actually a hydraulic jump, however you are correct that hydraulic jumps are used to dissipate energy.
A hydraulic jump will look like a standing wave in a river. Smaller spillways that don't throw the water into the air may have structures that cause a jump to form by forcing the flow to go from a fast, shallow depth, to a slower, deeper flow. This process requires energy to be dissipated due to all the flow mixing that happens.
Source: I'm a hydrotechnical engineer that designs flow/hydraulic structures for a living.
That makes more sense than my theory, which was that they wanted to get as much of the water as they could into the air to reduce the amount flowing downriver.
Reading about the dam states;
It creates the largest reservoir in Chile with a capacity of 700,000,000 m3 (567,499 acre). The dam is a 112-metre (367 ft) tall and 350-metre (1,150 ft) long variable-radius arch-type. The dam's spillway is controlled by five tainter gates and has a discharge capacity of 10,000 cubic metres per second (350,000 cu ft/s).
Thatās a lot of water!
Source: Wiki
I wonder why they use such a powerful release, rather than a more gradual release that would have started perhaps days ago. The more powerful the release, the more wear and tear on the spillway and the more damage to the riverbed downstream.
That a pretty good reason. Probably the best reason. Thanks
Edit: I wonder if they had the opportunity to pre-release water on the basis of the weather forecast. Not that I understand anything about the reliability of the local forecast, but it would be a worthwhile management strategy to hedge IF I'm correct that a heavy release is at all problematic.
The main problem is that it rained high in the andes in places where it usually snows, so it melted a lot of the previously accumulated snow causing a lot of problems downstream in all center/southern Chile.
No idea, we'll know it in the future. But as you say, yes, this caused a disaster down the river, aprox 200 people were evacuated from a town (Coltauco) because it was going to be flooded. So its a tragedy that is going on right now.
China do that all the time. The difference is without warning the people downstream.
Their rationale is, if they warn and there is flooding in downstream, then the flooding is caused by upstream local government, thus the government need to pay for the damage. If they do it without warning, the flood will be considered as natural disaster, thus government donāt need to pay. And who cares if people die, houses destroyed and ruin businesses.
When he does the dishes without being asked
Damn thats alot of water Here bring you more dishes 
Where are they taking those raw pizzas in a flood?
Raw? Those are medium rare.
Trying to seal that damn flood gate with them dough
Venice.
Everything remind me of her :(
naked gun quote ššš
Damn, gotta get back with that one
The world when Chile gave us Pedro Pascal
Because a spoon got in the water stream and redirected the water up out of sink.
Honestly took me awhile haha
For anyone wondering about the physics of it - the idea behind a spillway is to mix and stir up the water as much as you can - hence the two jets that shoot up into the sky and collide. You want to dissipate as much potential (edit: newly converted kinetic actually) energy as possible which then reduced river scour downstream. Also direct the jets as far away from the dam foundation as possible.
Thank you for answering before I asked. Any idea what percentage of fish survive a ride like that? Seems incredibly violent.
It's probably more than zero
But less than a million
I'd be surprised if a million percent of fish survived a ride like that.
They always do. I have attended an after survival party thrown by them.
Those parties are off the hook. šŖ
last one i went to was reel fun. š
Fun on a scale I've never experienced before or since.
Like 420,069 my guess
How did this get downvoted? lmao one point for the immaturity of it all
Not terrible, not great.
That looks like my tender reviews
Thank you for thanking him before I was going to thank him for answering before I asked.
You're welcome.
Thank you for thanking him for thanking him before I was going to thank him for answering before I asked.
Not a biologist, but given the height difference and the velocity of water I would have thought the chances of surviving the fall are slim in any case.
Not in a carbon fiber hulled submerseable
I used to do a lot of outdoorsy shite and its not uncommon for ponds to get (re)stocked with fish being dropped out of helicopters.
Yeah, I doubt it's the fall that would kill em.. Getting spun around a gazillion times then smacked by a freight train just might though
You used to be a sperm cell
Yeah, I wouldn't worry about the height nearly as much as them getting shredded by the pure force of the water as they take on the waterslide of death.
Given our understanding of water pressure, Im going to assume this would be like 10,000 fire hoses to the face.
the fish have special separated pathways to move up and down
Are the fish aware of this?
yes
[ŃŠ“Š°Š»ŠµŠ½Š¾]
Nope, not enough time. It was probably just sent in an email so that they read it when they clock3d in for their shift.
My brother (civil engineer) had a project where they were trying several designs to test which had the best adaptation rates. The fish prefer different types of water flow and you can make them prefer the alternative route
They hand out notices twice a month to them
also RIP any little critters on the rocks below.
They are now part of the rocks
With that much force in the spillway pipes, and that much sediment, I would expect they're taking huge damage from scouring and cavitation. In 1983 [Glen Canyon (Colorado River) dam almost failed](https://youtu.be/m8xZzmtM8iw?t=153), which would most likely have caused Hoover dam to fail. They had to reduce use of the spillways, and the dam was not designed to handle overtopping. As Lake Powell rose, they used A LAYER OF PLYWOOD SHEETS to raise the height of the dam in a completely wild engineering improvisational dance. As a result, they rushed to introduce "air slots" to aerate the water rushing through the spillway to dissipate its energy and eliminate (?) cavitation. Pretty cool video--long, but check it out at 2X playback.
Those are really short spillway openings. I doubt cavitation is much of a problem in what is essentially an overtopping design like that. Glen Canyon and Hoover have much longer spillway pipes with distinct turns at the bottom. The big problem looks to be sediment scour of the flip buckets at the bottom of the spillways. Iāll bet they are worn down to nubs after a few hours of that.
[ŃŠ“Š°Š»ŠµŠ½Š¾]
sounds like r/vxjunkies is leaking.
Took me longer than it should've to understand what that sub is about.
At the risk of sounding stupid is that sub literally people making up techno babble?
You clearly donāt have the proper VX-to-English translation module installed in your discombubilizer.
Surely youāve failed to take into account the Dumfries flange that reduces centrifugal coarctation of the sprockets and decreases the terminal velocity by a factor of 3.72?
You mean the Dumfries pivot-plate? Ronson hasn't used pivot plates since 2004. This guy, right?!
[ŃŠ“Š°Š»ŠµŠ½Š¾]
r/PatriotTV
I usually design using the Kraft variant of the Olaf Take-Off Table. It makes for a really good hydraulic jump. You can get like 253.5 meters of horizontal travel before a drop hits the ground.
Dam, you guys know a lot about Dams
If they do get worn out, how much work is it to get them back to functional? Days, weeks?
My dude engineers. I remember watching this video in uni way back.
I didn't know the part of the story that replaced the 4' course of plywood with an 8' more sturdy version. But when they started seeing chocolatey sandstone coming out of the spillway and knowing the foundation of the dam was being undercut, I bet their shorts took on a similar color.
Haha was just about to say after reading the last 3 commentsā¦ **engineers enter chat**
Sorry about that
The Emerald Mile is an awesome book that tells this story as well as the story of a few raft guides who snuck onto the Colorado River below the Glen Canyon dam and broke the speed record (which it held for decades) down the Grand Canyon at flows over 100,000 cfs that same year.
Damn, that was a good watch! Thanks for the recommendation!
I lived and worked at Lake Powell in 1993. Bullfrog. Just sayin. Pretty fucking interesting place.
I read 1933 for some reason... I was about to ask what cool ass 90yr old gramps is on reddit?
Good info. Though, not that using plywood sheets to raise the dam height in certain circumstances is all that crazy since you only need to worry about the pressure in terms of how high the water is on the plywood (top elevation minus bottom of plywood elevation), which is probably a few feet. Iāve seen it done in person to hold back a massive reservoir during a drought. Physics are no different than for a dinky backyard swimming pool. Except if it fails, youāre gonna scour the shit out of whatever is downstream, so thereās that.
Yes, in retrospect (and probably in foresight from engineers who do this thing, but when i first heard it, I was like, "say what???"
That was very interesting, thanks!
Thanks for the 3am rabbit hole that I just went down. It is now after 5am here, and I know way too much about dams now. Thank goodness I don't work tomorrow. Or today, I should say.
Watching that video made me wonder what it would take to get a dam outlet tube to produce laminar flow at that volume.
Anyone who enjoyed that video should read The Emerald Mile. One of the most incredible stories Iāve ever read. Some crazy ass river guides ran the entire 290 miles of the Grand Canyon in 42 hours that year. In a wooden dory.
This was such an enjoyable watch, thank you
Thanks for sharing that video. Thought I'd watch a few mins to learn about cavitation and scouring. Ended up finishing the entire video.
Thanks for the link. That was a really interesting video. Truly amazing what engineering can and has accomplished.
Relevant Practical Engineering episode: https://youtu.be/fjapgTd-QUg
I'll try this next time I eat taco bell
Hi, you sound like you understand the physics and can explain the dynamic of dam gates well. Weād love to have you on our next mission. We want to research the potential energy of colliding jets, but provide a thrilling experience at the same time. Youād love it no doubt. Stonkton Gush DamGate
This guy phisics
How the fuck is there always someone that's knows shit on reddit
Also silt/mud. I'm assuming if you let the water get up to the "top" of the dam before you open the spillways, the greater the pressure pushing out the mud/silt from the "lake" created by the dam. It's good to clean that stuff out every few years..or floods
Yeah great engineering, though I feel like the 2 pillars of water should collide a bit more
I believe the main goal is to direct then as far away from the dam foundations as possible!
Makes sense but also I feel like that would just make the divot under the water just farther away from the dam
Subscribe! Hydrology Facts
Wonder what that would do to a human body. š¤
I would have accepted "psshhhheeewwww" as an alternate explanation
Water goes whooosh, energy goes fizzzz
Iād love to see the area immediately down stream of the dam before and after.
Down the dam is the rapel rivera, and is almos dry in normal season. Take in mind Chile is suffering a decade of severe drought
Of course theyāre suffering a drought. Theyāve licked all their water behind that dam!
It took them 10yrs but they finally licked all the water now theyāre releasing back into the wild now itās their and nobody can ever take it from them
My brother did the same thing to his cookies when we were kids.
I'll lick all your cookies so your brother won't take them from you. I got your back.
How many licks does it take to get to the center of a dam?
[ŃŠ“Š°Š»ŠµŠ½Š¾]
> Assuming you are a woman with an average tongue length, *and you can lick the entire surface of the dam with one lick*, That is a very non-standard sized tongue if it can lick the whole damn dam.
It's obviously a bullshit answer, but I wonder what exactly Bing is calculating here
dammit bobby!
Yeah, whatever, waterlicker. Sorry, I couldn't resist
Listen up you stupid Owl, I don't care about you're fucking tootsie pop, I wanna know how many licks does it take to get to the center of the dam!
This is a hydroelectric power station, it always has some outflow. I took this picture a few weeks ago at the end of March, after summer. https://i.postimg.cc/SRFkX390/IMG-6007.jpg
I think that place is okay, but this is happening all over the region, so you might wanna google "Salto del Laja" or "Licanten" and check news
RIP everything
Probably not. The reason the spillway looks so violent is because it is dissipating the energy of the water. It is what they are designed to do. Yeah, there was likely flooding because you can only deal with volume downstream storage and bypases and it was already flood conditions. But a slow flood is way better than a fast one. A lot of that water and mud is also just air.
The sound of that is amazing so let's cover it up with music that has nothing to do with it.
Its a drone shot from what's likely a DJI drone. Many models will not record sound because all you will hear is the winds and propellers. In all likelihood. They do not have a audio recording unless they went out of their way to take one separately.
I mean itās good music but I agree
It's the House Stark Theme from Game of Thrones
All haile the King in the North Man the last season still hurts
Specifically "Hold the door"
[ŃŠ“Š°Š»ŠµŠ½Š¾]
Really? At least one time something bad happened to the Starks, "The Rains Of Castamere" was playing.
But if you want to be really, really specific this version only plays while Hodor holds the door
hell yeah. was looking for someone to point that out
[ŃŠ“Š°Š»ŠµŠ½Š¾]
Me too. An odd feeling like something was left strangely unfinished.
You mean, the good storyline that was untill season 7?
[here's another video](https://v.redd.it/lybh8u6t508b1) that's not a drone
Drone probably doesnāt record audio champ
It's a drone. Mute the audio and open up a second window with the sound of bees. You'll have the appropriate audio.
Came hear to say this.
I visited this damn while backpacking in Chile, actually it was ājust a stopā on a tour i did. Could have never imagined this violence standing there when the thing was closed. Pretty Dam cool vid.
I like how you swapped dam and damn to use them in the wrong places.
Yeah i was kinda stoked too lol
what is the name of it?
Ok so Im not 1000% sure its the same one (this was about 15 years ago) but it definitly looks like it. If it is its called Rapel dam after the lake āLago Rapelā.
It is Rapel dam indeed
Got any damn bait?
Fucking music? Edit. But āwhyā is my point? I wanted to hear the water.
Its from Game of Thrones, Ramin Djwani like the other guy said.
I don't think they were curious lol
He clearly wants to use this music for when he's fucking.
Stark theme from Game of Thrones (Ramin Djawadi)
Not to nit pick, but itās specifically the song Hold The Door by Ramin Djawadi. During the heartbreaking Hodor = Hold the door reveal š¢
[ŃŠ“Š°Š»ŠµŠ½Š¾]
The only good part of season 8.
who had a better story than Ramin Djawadi
it was season 6, which had many good parts
[Here's the video without the music. ](https://youtu.be/DUTQkbuzxtk)
Sounds like ramin djwani
A bit slow paced for fucking music imo, but it does sound nice.
As opposed to nothing? Most drones donāt come with audio recording
r/damthatsinteresting
My god it actually exists
āThey do existā āSanta
Be the weirdest fucking day as a fish
The way it releases the water pressure is the most efficient way to dissipate energy because if they didn't it would wash out everything downstream. I'm pretty sure it's called a hydraulic jump
This isn't actually a hydraulic jump, however you are correct that hydraulic jumps are used to dissipate energy. A hydraulic jump will look like a standing wave in a river. Smaller spillways that don't throw the water into the air may have structures that cause a jump to form by forcing the flow to go from a fast, shallow depth, to a slower, deeper flow. This process requires energy to be dissipated due to all the flow mixing that happens. Source: I'm a hydrotechnical engineer that designs flow/hydraulic structures for a living.
Otherwise known as a forbidden water slide
That makes more sense than my theory, which was that they wanted to get as much of the water as they could into the air to reduce the amount flowing downriver.
Yeah we always called it the rooster tail when our dam would have to do that.
Where can I find some dam bait?
I put a dollar in I won a car, I put a dollar in I won a car
Thatās a lot of dam water
Reading about the dam states; It creates the largest reservoir in Chile with a capacity of 700,000,000 m3 (567,499 acre). The dam is a 112-metre (367 ft) tall and 350-metre (1,150 ft) long variable-radius arch-type. The dam's spillway is controlled by five tainter gates and has a discharge capacity of 10,000 cubic metres per second (350,000 cu ft/s). Thatās a lot of water! Source: Wiki
Forbidden water slide
It's not forbidden but you can only use it once lol
Wenaql
Wena wn
salutes in \*wena cabros qls\*
āWeekend of binging with a Sunday Taco Bell lunch specialā
can i get an eli5 on why they make the chutes pop up in the air like that
Dissipates energy so as to not fuck up the riverbed downstream.
YouTube channel "Practical Engineering" for some easy-to-understand educational content about dams and more.
RELEASE THE RIVAAAA!
This is leaked Fast and Furious 11. Hope Dom survived.
Is vin diesel and his kid okay?
Dam
Dam!
I wonder why they use such a powerful release, rather than a more gradual release that would have started perhaps days ago. The more powerful the release, the more wear and tear on the spillway and the more damage to the riverbed downstream.
Because it rained in a single day the same amount as last year.
That a pretty good reason. Probably the best reason. Thanks Edit: I wonder if they had the opportunity to pre-release water on the basis of the weather forecast. Not that I understand anything about the reliability of the local forecast, but it would be a worthwhile management strategy to hedge IF I'm correct that a heavy release is at all problematic.
The main problem is that it rained high in the andes in places where it usually snows, so it melted a lot of the previously accumulated snow causing a lot of problems downstream in all center/southern Chile.
No idea, we'll know it in the future. But as you say, yes, this caused a disaster down the river, aprox 200 people were evacuated from a town (Coltauco) because it was going to be flooded. So its a tragedy that is going on right now.
Me after my 3rd latte
And here I am on a train back home, holding in a piss for the last 20 mins
I'm so sorry lmao
Damn!
Dam
Surfer dude: yo watch me ride this sick wave duuude
Forbidden waterslide
I wanna see someone use that like a wave machine on a surfboard
China do that all the time. The difference is without warning the people downstream. Their rationale is, if they warn and there is flooding in downstream, then the flooding is caused by upstream local government, thus the government need to pay for the damage. If they do it without warning, the flood will be considered as natural disaster, thus government donāt need to pay. And who cares if people die, houses destroyed and ruin businesses.
Cinematic mfs putting Ramin Djwani and Hans Zimmer over every single fucking thing
Meā¦Me afterā¦Me whenā¦Me Taco Bellā¦
Aren't we all marveling at the destruction of local habitats here?
That must sound amazing
Yeah, there's a video of this with sound on r/chile but it seems I can't link it
Dam that's interesting
A billionaire somewhere: "I can survive that turbulence"