How Do Spillways Work?
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- Опубликовано: 11 сен 2024
- We normally build a dam to hold water back and store it for use in water supply, irrigation, hydropower, or flood control. But sometimes we have to let some water go. Whether we need it downstream or the impounded water behind the dam is simply too full to store any more, nearly every dam needs a spillway to safely discharge water. The spillway is a critical part of any dam and often the most complex component. So how does it work?
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One thing I think you should include, "Then things go wrong" show example on failed structures and lessons learned by them.
"Very rarely, things can still go wrong, because this stuff is incredibly complex, and sometimes an event is so extraordinary that no one could have foreseen it, and to make things completely safe even for unprecedented inimaginable events is incredibly EXPENSIVE for the community itself, and 99,99% of the time it's useless".
This would be more correct.
Yeah I was hoping to see Oroville Dam examples
@@Mandorle21 If it weren't the real world... In our world, 0.01% of cases is all that matters.
As evident by already mentioned Fukushima...
Or do you agree that it's alright if bridge doesn't fall apart in all cases except when YOU drive over it?
Daniel Wiegert Look up the Oroville Dam disaster, that’s a recent event where the emergency spillway of the tallest dam in the US was just hours away from failure due to such extreme water inflow.
@@prax3956 Exactly my thoughts.
I'm a civil engineering major at Boise State and I just wanted to say that I watch your videos to supplement my coursework all the time. You make it fun and interesting to learn about what most people would consider mundane. So thanks.
One important advantage to note about controlled spillways is that they allow the dam to lower the level of the reservoir significantly below normal in anticipation of a large inflow. This allows them to absorb far more volume while maintaining the same outflow during the storm (or less to assist downstream dams that are picking up extra flow from the watershed between them).
I think it's more cost effective to only build one big one of each, although an uncontrolled spillway might be used as a backup for the backup spillway!
@@chiaracoetzee The dam shown at 2:40 appears to be set up like this, yep. Most principal spillways are controlled, I imagine.
@pmailkeey oh there are things that can go wrong, like a broken emergency spillway channel
Unless the fort peck dam fails, that will work for the dams downstream
So you want some manned and some unmanned as redundancy?
Me: It's 12:57 AM, I'm gonna sleep now.
RUclips: Hey, do you wanna watch a video about spillways?
Will watch 10/10
1:19am now for me 😂😂
3:25AM and I join my fellow perverts watching engineering porn.
Hahahaha saaaame it's 12:20 am rn
3:38 am. I should be in bed but this is my quiet time lol.
jo SAMEEEEE
I really love it when you cover new material that incorporates previous videos. That building of knowledge makes me very happy. When you talked about weirs and I didn’t have to go back to those videos because I’ve already watched them and knew what you were talking about...made me feel a bit educated on hydraulics. Can’t thank you enough for putting out such quality content.
I have unexplainable terrifying fear of these round spillways even looking at them on the screen.
Yeah, I keep wondering what would happen if I get caught in one of them
There was a tv show called "fringe" where a tiny black hole or vortex appeared in the middle of a river in new York. It looked exactly like this.
Because it looks like a black hole. It's a primal fear because we know what it means.
@Luciphene I can't imagine whirlpools were commonly encountered by humans. This would be a primordial terror if so. In fact my use of primal honestly was too glib. I think it's one of the most ancient fears we have in our DNA.
@@Krystalmyth you mean black hole as in caves, cave-ins, and similar stuff? Or black hole as in the actual phenomenon in space? Because if it's the latter, you just made the joke of the year, lol
This channel was one of the main reasons I chose civil engineering as my major. I can't thank you enough for the excellent, high quality videos.
Congrats on 1 million!
I'm not an engineer or a tech guy, but IMO this is one of the best channels on RUclips. It's an invaluable source of information on how the world around us works.
If you’re still in school I wish you luck mate
I’m a project manager and have spent a lot of my career knee deep in mud, sewers, conflicts etc..... I’d hardly call what I do “Civil”!!! But it sure is FUN!
Jan: chill
Feb: chill
Mar: chill
Apr: chill
May: chill
Jun: chill
Jul: chill
Aug: REEEEEEEEEEEEE
Sep: chill
Oct: chill
Nov: chill
Dec: chill
And then very THE NEXT YEAR:
Jan 1:Virus time
:)
Justis Chew Yees but rainfall iz chill
Congratulations on 1 million subscribers. Love your videos. So educational and informative. Keep it up.
thankyou so much!!!
aw you are too kind! I am also very happy that one million people love my vids :D shoutout to u
@AJ Martinez well I mean some people just want to say that they like the vids ,you know what I'm saying
Rob Townsend ‘day e
@@iwillstealallyourcookies1873 why did you reply? It was directed to the actual creator.
I worked on the control system for a spillway at a hydroelectric dam in BC, Canada. A key component was to maintain minimum flow to keep fish alive in the river. We used redundant PLCs and three instruments from two manufacturers for every measurement required (level etc).
A little woodturning. Classic Grady.
Hey
ruclips.net/video/XG9M7JjUN54/видео.html
I learn more on RUclips than I ever learned in school.
-Josh Otusanya
You forgot the ua
I think that is because RUclips is more a free market of ideas than school. Many teachers in schools appear to be there just to earn money to pay the bills, rather than being genuinely interested in what they teach. They probably have all manner of restrictions on what they can teach and how they can teach it too. The guy in this video for example is clearly interested in what he talks about and was able to build working models to express his ideas and I don't remember any teachers doing this.
@@BurtMeister RUclips isn't really a market (sans advertising). There are no buyers and sellers of videos like these. It's more accurate to describe it as a post-scarcity system.
😂.. was to about to ask who the heck is that medieval person? nd saw your name..
Wendover = Planes and trains
Practical Engineering = Concrete and water
Real Engineering = everything :D
It really means that someone else built it - long ago (before the West was created). Michelle Gibson's channel talks about it
@@jkane764 I just had a look. Michelle Gibson is actually just a crazy conspiracy theorist. If there's anything of value on her channel it's not worth digging through the 99.9% of it that's worthless trash.
@@googiegress >> Michelle Gibson is actually just a crazy conspiracy theorist.
It appears that the term "conspiracy theorist" is reserved for individuals who do not support / affirm the falsehoods and misinformation disseminated by the mainstream media and/or public school system at large.
Her research (and the research of ~ many ~ others ) all point to the same conclusion: much of the infrastructure and technology in use today was not created by those who are currently benefitting (financially) from its sale and distribution.
@Googie Gress
>> 99.9% of it that's worthless trash.
What is admirable is that she (again like many others) utilize empirical data and simple observation to support her thesis.
Simple observation = the Horse and Buggy culture of the past could never have built the Capitol Bldg., Harvard, etc. as they simply did not possess the skills to do so.
In the end, 1 + 1 = 2 (no matter how much you may find such a fact as being distasteful).
This is my last response to you regarding this topic.
"Water can cause major damage" just use FLEX TAPE
SpaceDave1337 I wonder what the appropriate dimensions of flex tape would be to repair a dam at full scale
@@thefloridamanofytcomments5264 A dam big one😂
@@Mehrunes86 you need to be PUNished for that one.
🤣😂
@@Mehrunes86 😂🤣👍
All of this to avoid dam-age, Brilliant !
Eh, I mean... Skillshare
He sounds like the flex tape guy
Van-Damme you, Pun-Man!
Absolute mad lad
Horror holes! Imagine falling into on of these
My cousin almost
You'd be okay provided you could fit through the narrow end of the cone.
@@BurtMeister and have good pulmonary capacity. And don't hit one of those jumps.
I have
I can stand on the edge of a roof and get a little tingle in my gut and be okay, but if I do have a phobia then this is it.
From an ecological perspective, modern spillways also need to consider downstream impact of where the water is released from: surface water in reservoirs is warmer than the deeper water. Releasing cold water downstream negatively impacts nearly all river life so allowing the surface to run off alleviates some of the harm that dams cause to the ecology of the river. In addition, simulating minor floods downstream also improves the ecology of certain streams: floods are natural parts of river ecosystems and minor floods are needed for some fish to successfully spawn. There are also structures in many dams now to assist fish movement upstream, some passive and some active: fish ladders can be impressive structures in their own right.
You should watch a documentary called Dam.nation
but dam water in general is warmer than a river, because the surface is higher to heat up from fhe sun
I always shit myself when I see these things to be honest, at least when I was young. They look terrifying.
Yeah bell mouth spillways look awful
I could only imagine falling down in the pitch black with the unsure question of drowning or falling flat.
I felt the same way as an adult, staring down the 30 foot wide tube of the spillway at Fontana Dam. Something about it just makes you uneasy.
There is a case of a girl named Emily who had swam up to one of them to have a look when a currant picked up and dragged her in, she managed to hold onto one of the lips of the spillway but water was pouring fast onto her, she held on for 20 minutes before losing her grip and fell 100 meters to her death sadly
That's why we always swam in the lower reservoir. The roar coming out of the upper one was straight up frightening. A circle ten foot across sounding like a jet engine at full throttle as it swallows up thousands of gallons of water 24 hrs. a day. Bavington PA.
I am a Civil engineer. You're video is the most clear and concise explanation of spillways I have ever see! You should be very proud of your self! Please keep up the good work. I will be pointing the new graduates in the office towards your channel :)
Bell mouth spillways are really neat to watch, because they let you see how flow changes.
--If the spillway was just a straight piece of concrete pipe, the flow would be more prone to do unpredictable things. It's easier to choke the straight piece of pipe. A laminar straight pipe drain would require flow to be fastest at the very center of the drain pipe.
--With the bell mouth, water that approaches the drain is allowed to gain downward velocity faster than lateral velocity, which "shoots" the water along the surface of the pipe instead of at the center-line, which helps the turbulent flow make the pipe act bigger than it really is. The high velocity region is the complete perimeter of the pipe instead of just the tiny point in the center of the pipe. The added benefit of turbulent flow stops sediment from collecting in the drain.
You should do a few videos on some of the famous dams around the world, talk about how they work and the main reasons why they were built, and wether they still serve that purpose.
In Québec, LG-2's spillway is called "The Giants' Stairway" : 10 steps 10 metres (32 ft) high and 122 metres (400 ft) wide, each step is larger than 2 football fields
Congrats to 1 million subs!!!
thanks bro
1M subscribers is not enough, but it's a good start!
@@SureShot_2 why did you reply?
5:52 *Put generators to spillways*
Well that's a lot of electricity:)
Smart
Spillways aren't used everyday so putting some turbine there will just spike the cost nothing else
The spillways are in use when there is a surplus of electricity on the network but consumers are not consuming all the electricity, that's why the water level becomes too high and must be dumped out. That makes that clean hydroelectricity is then wasted. That is also because of private electricity companies who won't stop their pollutant coal electricity plants during those hours of low consumption but high river levels.
@@korelly No. Wrong.
4:18 This particular spillway scared me as a kid, as it was on the lake near where I grew up. As a kid, I was scared that it might swallow me, even if I was miles away on the other side of the lake.
4:11 It can change as the bell mouth chokes , but how does it change?
As a non-engineer guessing, I'm expecting it gets an additional "pull" from the speed the water picks up as it chokes, that ups the capacity of the spillway, but it would be really interesting to hear more about that.
Have you made a video about diffrent kind of fish ladders, elevators and steps? Lots of dams yes, but it affects how fish reach their breeding grounds. There is a lot of various solutions to the problem, would like to see your take on that. I would watch :)
This would be a pretty good subject for a new video, yeah.
Yes, that is an interesting idea! And different structures have to be used in different situations. Tropical fish, for instance, behave differently in ladders than temperate climate ones.
Hey Grady, I found your engineering to be quite practical. Keep up the good work.
This is one of the best educational channels on RUclips. Great script, fantastic visuals, and excellent topics.
Congrats on the 1 million subs! Well deserved.
👍 I'll second that! Congrats! 🥂🎉😎
Mike Gustafson Absolutely agree. Excellent content.
I know, right? The practical engineering on this channel has been surprisingly helpful too.
As someone who's Dutch, i laugh at water.
There's this common myth that we have some of the best and most advanced hydro-engineering projects in the world.
That's a lie.
We've simply abused the water so much throughout history, that us being near it sends it running away in terror.
A simple way to test whether someone's Dutch, as such, is to get a glass of water and throw it at them.
Now, since the water isn't of sufficient volume to escape, the person you're testing wouldn't repel it.
If this were, for instance, and ocean, a scene not unlike that of Moses (was he Dutch as well?) would play out, with the water simply retracting wherever the Dutchman went.
Instead the water avoiding the individual though, if you are very quiet, you can hear a million little waterdroplets faintly scream for their lives. :)
why is this the funniest thing ive ever read
Is that why it is called the "Flying Dutchman"? Because the water dare not touch the bottom of a Dutch ship?
😵
1 million, epic! Great video as per usual. Love from Australia
Same here
same auzi oi oi oi
Jake Turner FPV is it true you guys get demonic birds swooping down in the summer?
Oh my gosh Is that bread? Sure is
*@Oh my gosh Is that bread?*
Yeah they’re called magpies lmao, they don’t always attack but when they do it’s advised to prolly run.
6:43 that was lyrics dude 🙌🏽🙌🏽
5:09 "major DAMage"
that got me lol! Nice one.
Phil Swift popes into my mind too
heh heh heh
i was looking for the comment to point it out xd
@@ghujka sguzjj
Sega d vfr
Congratulations on 1 million! Well deserved. Your videos are very informative, and put together really well. Thank you!
Congrats on the 1m, Grady. Fully deserved. All the best
Next can you do a video explaining how the hell they manage to build a spill way like the morning glory one!?
It ain't called that. Its the Glory Hole. Yeah. We get it.
Remember, the water wasn't that high before they built the dam. So they could build the spillway structure while the water is much lower then the opening of it before the dam is complete. That's my guess
thedexterbros nice
just drain the river with cofferdam first, reroute the river flow, and construct the main dam and all facilities on dry land..
"Next can you do a video explaining how the hell they manage to build a spill way" - easy - they didn't build it. There are complex engineering projects (like dams) in even the most remote (hint: non-populated) parts of the world. Reason: they were built by others. Michelle Gibson's channel talks about it and she says who actually built it as well. Another interesting one is Jon Levi
3:22 - that kind of spillway is 5 million types of 'nope' from me. I am genuinely terrified of those things.
Iv been inside one local to me! Entered from the bottom end though
@@camnationm8 tf imagine if water level got high while you were inside!
Ha ha, I’m the same way with pool drains; I know I won’t get sucked in there but still. Scuba diving in the ocean is fine though. Weird.
Dared even though the reservoir was super low and it'd of probably taken a few days of heavy rain to overflow I couldn't help but think that same thing the whole time I was inside it 😂
And those are generally the least dangerous should you go down one accidentally. Unless you somehow managed to fall into one that's dry.
Also assuming the outlet doesn't crash you into a rock face, but rather something soft like a pool.
Pool drains are DEADLY though if you have anything that can get sucked into one, like long hair or you manage to cover it such that it gets plugged. You won't come free from it and drown.
"Robert, it go down"
"It don't go down"
Grady, how I wish you were around when I was a Civil Engineering student. Your work is beauty, as Engineering is.
Congrats on 1 mil man!!!! Just found your channel and my whole family loves it!
i suck at physics but i love these kind of videos
Yeah, thanks for the video, so professional
-with the video footage, satellite images, pictures, animations,
great job!
Also thanks for explaining 'spillways' (always wondered what those things were in the pond lol) 😃♥️🌿🐳💫
even jesus agrees
Lol
High quality content... Massive respect from a learner from Pakistan 🇵🇰.
As an HSEA Officer, it's absolutely helpful for me to understand do's and dont's and to let my workers aware of the potential hazards involved in their engineering tasks.
Congratulations on getting to a million subscribers Practical Engineering!
this view reminded me a few weeks ago how the dam literally less than a mile or so away had doors open for a few days just from all of the rain and the sound that it made, what a thing to hear
*_Congrats for 1M subs🎉_*
you're welcome
Love your profile pic for dark viewers
RUclips g
Congrats on 1 million subs! Yours is one of the few channels on RUclips that I'm always excited to watch a video from. You have some of the most consistently high production quality and phenomenal explanations. Here's to another million!
This video was found after the lake Dunlap dam collapse, don’t lie
can 200% confirm
@Kuru I really don’t think this will, but glad you’re here anyways
Absolutely. And it was bcs of the thumbnail
Wait what happened? This was just in my recommended.
well i mean this video did come out after the collapse happened
I would love to see a demonstration of the importance of the bevel cut on the end of a pipe spillway and the physics behind purging the air bubble in a pipe spillway.
It is almost impossible to explain that it requires a head pressure of twice the diameter of a sloped barrel spillway to purge the air bubble and load the pipe.
Would've been interesting to hear you talk about some of the ecological considerations--e.g., minimum ecological flows, fish ladders, etc.
Congratulations Grady!
Congrats on 1,000,000 subs. Thanks for all the swell videos
I have mechanical engineering qualifications and never dawned on me the purpose of hydraulic jumps. Very cool! Thanks for your excellent civil eng breakdowns.
1MIL SUBS CONGRATS!
Enjoy watching your content and the information being learned, keep up the great work
I came to learn this bc I love fishing, and learning where how dams are built and how the energy is set to dissipate creates the seams where fish will sit. Thanks, always learning something new.
That moment when you get excited that "your" dam makes an appearance in the video. Lake Hartwell Dam -- woo!
First time watcher ! I loved learning , congrats on 1 mill 👌🏻
great video! love these hydraulic/hydrologic content
I'm addicted so much by you that I find a way to charge my phone and try to watch at least one vid before going to bed. You just show what you talk about. Not any complicated stuff
Morning glory spillways are so scary. Just the sheer volume of water going into those monstruous things makes me cringe
CB falling into one is one of my worst nightmares. The pressure at the bottom is what kills any unfortunate individual that takes the plunge, often great enough to break their back in the pitch dark hate hole. I just shiver thinking about them
@@werds1392 yikes
@@werds1392 Thanks for letting me know that I'm not alone with that fear
@@werds1392 e.e ugh my spine
Congratulations on 1,000,000 subs, Grady! Since discovering your channel a few years ago, I haven’t driven past some form of civil infrastructure without considering its purpose. Here’s to the next million!
Congratulations on 1M subs, absolutely love your videos. Keep up the awesome work.
Due to the upstream rainfalls and flooding, the Arkansas River is flooding right now and the dams are wide open, some dams are being overtaken and had to be evacuated. In Little Rock, Arkansas we are at a 500 year flood level at 29.5’ above flood stage. Dams and weirs are so very important to controlling water. Great videos. There are videos showing where the river is actually causing streams and creeks to flow backwards. We have lots of homes and low lands currently under water. The flooding has set a new record since the dams have been built back to the mid 1900’s
The auxiliary spillway on Canyon Lake Dam has been used 1 time.
The 1 time it was used, it created a giant gorge from the hydrology effects imparted on the surrounding land.
The dam on lake Dunlap which is just below canyon just broke last week, bums me out because I used to fish there a lot
Your videos are super interesting! I'm about to go into my senior year of Chemical Engineering and I'd never really delved deeply into open channel flow and hydraulics since our world is pipes and process equipment!! I've learned a lot more thanks to your channel. Keep it up! Thank you for all of this and hopefully might see some ChemE stuff in it later!!
Congrats on 1M subs.. keep making these quality stuff 🙏🙏
You should do another video on spillways used for river control than the regulating of reservoir levels behind dams. I'm thinking of spillways such as Morganza or Bonnet Carre
congrats on 1M. Those spillways of the hoover dam will probably never be neede again 😂
I'm an electrical engineer but I'm vastly fascinated by these videos and this helps me become more well rounded in understanding of concepts in engineering.
Funny how calls it a "morning glory," rather than the more common (but easily misinterpreted) "glory hole"
ha! i came looking for this comment. thank you. I have never heard them referred to as morning glories.
I think he was trying to avoid the obvious sexual RAM-ifications.
I live 20 mins from the lake he showed. We all call it the glory hole. Literally everyone. Lake Berryessa Ca
Hmm... I just call them lake holes.
The term Glory Hole is also used in mining and in glass making.
These two usages have been in use far longer than the more recent vulgar usage.
I am student at a French civil engineering school, your videos are so easy to understand that we watched a few videos of yours in our English class, thought you'd like to know !
Congratulations, the RUclips Algorithm has blessed your episode!
4:00 what amazing and hypnotic design 👌🏼
I must be getting old, because I found this really interesting.
Nah man. I'm a teen and this is fascinating.
@@victoriat8922 Thank you for this comment. Getting old sucks. lol Helps alleviate some of the pain.
I posted elsewhere, but for anyone interested in seeing a failure of a spillway, the activation of an uncontrolled emergency spillway, and what the power of the water really is, look up the Oroville Dam spillway failure. It was 2 years ago and they are just finishing filling it up after repairs for the first time this week.
My greatest fear is falling in.
You wouldn't, unless you were in a rubber boat
Well if your boat was too close You would fall in don’t worry you can’t even get close to
@@Kansasavation jump out of the boat then....
Василия -x- Vasilia water with suck your body in
and here i am just thinking that it seems fun to slide down most of em. if it wasnt as lethal as it is but still
I'm glad I live so close to the St. Lawrence Seaway. That was an insane engineering feat in its time. It still is, absolutely mesmerising to look at.
Congrats dude 👍🏼
My 4 and a half year old son just sat and watched this video with me without complaining that it was boring. I think you got the presentation down pretty well.
The Oroville dam flood will be amazing...but catastrophic.
that's awesome to see Wilson Dam in Florence Alabama wide open at 4:48 I was there during the heavy flooding earlier this year. got some nice shots and mosaic scans with a drone during it.
For those wondering, 4:17 is the glory hole in Lake Berryessa in northern California!
What happens if you're swimming & get pulled down it?
Jon Jukes you’re not allowed to go anywhere near it, but you would shoot out of the bottom of the dam at an insanely high speed, but probably not alive😅 its pretty massive
@@pedrotraviesa6685 Ok, I was just wondering in case somebody tried to hop the fencing and go for a swim.
Jon Jukes haha ya everyone wonders the same. there’s a video of a duck that accidentally went into it. they say he survived though!
Congrats on the 1 mil mark. You Earned It!
Also what a great video for making that mark. These are by far one of the most fascinating engineering marvels.
Congrats on the 1m subs man deffinaly earned it! Keep up the good work!
really enjoy the education, so much of them remind me of my dad, an optical engineer... i was his lab assistant all my life and probably where i got an interest in engineering in general and how things work
I love watching spillways spraying water, especially in a very large dam like Three Gorges in China, it's like man-made Niagara falls.
Congrats on 1 million!
And 9 on trending? Might have even been higher.... Awesome! Love how your channel communicates engineering concepts to the general public.
If turbulence is the issue, why not create laminar flow? #smartereveryday
But how. That would probably be incredibly hard.
I actually don't now I would just assume
My private lake has two main morning glory spillways and an emergency drop spillway. It was originally a wooded creek that would flood out every spring, so the previous owners built a lake and a clay earthen dam to store it.
Average depth is about 15' with a max depth of 25' near the dam and an estimated acreage of 1.9.
Perfect case of dam capacity issues: Houston, TX - Hurricane Harvey - August 2017
I've been bingeing this channel videos for about hours now. Learning so much. I love it. And for the fact I can know identify the various old dams and drains in my town.
Ironic how the video came out on the same week as the morganza and the bonnie-carrie spillways are open because the Mississippi River is about to over flow
Drop shaft spillways are scary stuff if you see them in person. There’s a dam where I live with 4 large dropshafts built into the main structure, and when the dam reaches the potential for overflowing they open gates in the dam that allow excess water to flow into the spillways. Walking next to the railing on the dam and looking down these giant tunnels that descend into pitch-black darkness is a really harrowing experience. I know I’m safe as long as I stay behind the railing, but I can’t help but imagine what would happen if my phone, camera, etc. slipped from my hand and plunged into the darkness, never to be seen again
In your spillway model you say the flow can change as the model chokes, but you fail to explain or mention how it changes???
Sir, you are an engaging presenter. Believe me, I am a gas turbine and diesel engineer by training, and as I know very little about structures and concrete, and especially the hydraulic jump, I have enjoyed the whole lot. Some of this stems from the Toddbrook Reservoir situation here in the UK, but thanks alot to your channel.
These videos remind me what the other college students were doing while I was drinking beer & taking my liberal arts classes.
Glad to see actual content get onto the trending page
I always find myself wanting to slide down one of these chutes they look like water slides
Your massive balls wouldn't fit
I'm no engineer, but your videos are always very interesting.
Is the structure at 5:30 pixelated or is it just some weird optical illusion?
I think that there are steps to help slow down the flow of water over the spillway. And for some reason it is painted black on some parts of those steps.
It's a video compression artifact, here's a nice video on the topic: ruclips.net/video/r6Rp-uo6HmI/видео.html
One of those videos of the dam with the hydraulic jump was actually gavins point dam. That was during a major flood in 2011 and it actually almost destroyed the dam. They were letting 80,000 cubic feet of water through per second and that was the most they had ever let through.