Ed Kern - 2013-08-19
http://krcproject.groups.et.byu.net/
I have absolutely no interest in dams or how they work and all that but I watched the whole thing, very well presented and very concise. Thank you.
Ditto!
I have no dam interest
Therein lies the beauty of YouTube.
Same.
Dams are here and learning about them may save your life. Information is never a bad thing.
Here in Washington on the Yakima river we have a section that looks exactly like this. It looks so small and simple and I was considering going over it in my kayak so I'm very thankful you made this video. You just might have saved my life.
This river is just hours away from Yakima
@Elon Must Your point is?
@Jamie Lonsdale You talk to make noise
You should have gone. Thinning of the herd
@The Frase Sorry bud, god is on my side. I’m sorry you’re life is miserable I hope it gets better.
This was both very informative, and a little creepy in how dangerous such innocuous waterfalls are.
I live near the Bolton Strid no one has made it out , as result of an accidental fall Ever .
Exactly... Which is why a dumb sign is not a good enuf thing to prevent deaths!!!!
@Rob Crowley The Strid is famous and it is especially creepy. It looks like such a little thing....
Not sure how this got in my recommended box, (I enjoy an engineering video or two, but mostly electrical engineering) but I have to say, this is a really well put together presentation, and also a surprisingly relevant one.
I do some whitewater kayaking and I have dealt with some "sticky" holes where this same phenomena was occurring, but for those they were always small so worst case scenario you had to swim out and get you boat and paddle later.
I never really thought that much about where else such a danger might exist. I guess I never took the time to consider the danger of what looks like a relatively low risk water feature. (thankfully I never had to deal with one)
We see a lot of "research" projects nowadays that seem to lack application, (obviously that is not always a problem) but it is nice to see someone taking the time to both raise awareness and also propose a solution to a problem that can and should be easily fixed but has not been due to lack of awareness.
Anyway thanks for making this. Also that is a really neat flow channel apparatus.
Thank you for this video. A work colleague of mine and her best friend recently died whilst canoeing over a weir. They were very experienced. I wanted to understand what could have possibly happened. The Ken doll part of the video is shocking but informative, thank you.
This is fascinating, and kind of creepy imagining the terror/panic/anguish of the people who have been caught in this being represented by the Ken doll.
Not sure how this came up on my feed, but glad it did. Two of those deaths shown on that map appear to be at low head dam structures near where my grandparents lived. I remember seeing them as a kid, when we would visit, and being almost instinctively terrified of them. They are deceptively small drops, but I saw (more than once) whole fallen trees get caught in the churn at the bottom, and roll for days, being beat to pieces the whole time. It didn't take much convincing on the part of my parents to steer me far clear of those dams.
Nice presentation. White water paddlers learn about drowning machines early on. In Toronto, weirs were put on the Humber and Don rivers after hurricane Hazel in 1954. I can remember two drownings on the Humber and four people and a dog at a weir on the Don. Three more drowned on the Credit River. That dam was blasted. The Don River weir was filled in below the weir and is now an easy run.
Many of the people drowned after going in the water to rescue their dog. Usually the dog swims out and the owners drown.
In the spring tree trunks and logs collect in the trough making it real tough to come up for air.
If you are about to go over, try to jump as far as you can downstream WITHOUT your life jacket; then head for the bottom where the current can take you past the boil.
How do the dogs make it out?
@NoriMori They don't.
This problem has been publicized in Minnesota, a state with several (possibly many) lowhead dams. It helped me appreciate the danger involved when DNR safety experts described these as "drowning machines." Few things in life are so dangerous while looking so benign.
When I was a kid, there was this popular swimming spot in San Marcus that had a low head dam that was terrifying at times. I almost drowned when I got caught in the whirlpool then dragged down to the bottom just like shown in the video. Very cool and interesting presentation to someone who knows nothing about dams!
Same here. I was on the Comal River in New Braunfels when I was a kid and they had one of those dams where the water flowed over it but there was a section cut out of one side known as the chute where the water flowed through and not over which created rapids and was where everyone would go through on their tubes, but I went over the part where it flowed over and got knocked off of my tube and remember tumbling around underwater hitting rocks and such not knowing which way was up and out of nowhere someone jerked me up by my arm and more than likely saved my life, luckily the water was shallow enough on the other side where people could stand next to the boil without getting caught in it. I don't know if that dam still exists, it was in a place called Camp Warnecke and that was back in the 70's.
Yes, as an open water swimmer who often swims in rivers, I have always known these as dead-head dams and have and understood them to be deadly.
Me and my friend got caught in one of these in Missouri near St Louis. We were sucked under in that pool about 4 times (without flotation). It was a rather large waterfall too but I managed to push off the ground at one point and escape. Very terrifying though.
At first the idea of a drowning machine was horrifying and fascinating since it’s not a subject I was ever familiar with or even aware of until recently. But the more I find out about low head dams and how water flow really works it’s become so much more interesting. Thank goodness there are people out there who are trying to get these dams retrofitted and save lives.
Fantastic work. Important lessons for people who come into contact with these conditions.
Amazing. I couldn't understand how those 4 people drowned on such a small waterfall. Now I know
Really interesting video. One factor that I would like to see explored also is the overall shape of the weir (UK word), straight across can be particularly nasty, but curved structures can be better or worse as lateral movement can get you to a weakness in the flow. It is the uniform nature of weirs that often makes them so much more deadly than natural features, which do not often go completely across the river.
Also another solution which exists already is to have a separate canoe ramp for boat users to use which can just take them right over the weir at a shallow angle with a great deal of horizontal momentum with an escapable hydraulic feature at the bottom, I would also have thought his uses less concrete.
Perfect presentation of the well-known (to whitewater kayakers/rafters) dangers of a low head dam. When I was a beginning kayaker in Arizona, I was taught to fear these. There is (maybe was) one particular low head dam on the Salt River that was known to have killed several people.
I just literally watched the original version of 3:45, very scary stuff. They were out trying to find the body of a firefighter that died the previous day. 2 of them died and 1 made it to shore. Low head dams are no joke.
that was the scariest bit, you can see the body language of 'oh shit this is fatally bad' when the boat is pulled towards that huge overflow before being sucked under. That'l give me chills whenever i see another low head damn
I think public education is definitely the most important solution. We try to spread the word in kayaking groups especially among recreational and fishing boaters who otherwise wouldn't know. I feel like swiftwater rescue teams - while important - are more for recovery at that point unless they happen to be on standby when someone goes over, which simply isn't feasible. In the meantime, until we can retrofit, alter, or destroy as many of these as possible, keep spreading the word man! Great video.
Probably one of the most valuable videos on the internet. I'll be looking for these for the rest of my life, and make sure others know too. Excellent pacing and presentation, and the flue demonstration really drove the point home.
Very clear, great job.
I hope you don't mind if I add a few safety points.
First, the low head dams are the ultimate in "drowning machines" because they usually go from bank to bank with no still water eddy from which to perform a rescue or for the trapped victim to escape.
On rivers you will often encounter the same kind of currents below rocks or ledges but, usually they do not extend the full width of the river. In many cases the edge of the "hole" turns downstream and if the trapped victim can work across the face of the wave can flush out there.
When viewed from upstream holes with this "friendly" edge look like a smile. Other holes where the edge is turned upstream will not flush you and viewed from upstream they look like a frown..... whitewater boaters avoid frowning holes.
In May of 2002 I found myself stuck in a class C hole on the Housatonic River. I was rolling up but, my kayak would get flipped again. I could not escape at the edges so I knew my only way out was DOWN. I pulled my skirt and dove for the bottom, the water passing under the hole flushed me out and downstream.
Whitewater boaters discuss diving down, balling up and other tactics for escaping holes. Unfortunately, the lay person has not had these discussions and the last thing that will cross their mind in their fear is diving under water.
BTW, have you considered what happens when the dam is built on an angle to the river rather than perpendicular to the flow?
Thanks for that info, davekingpt. I wondered if diving deep or balling up would help get me out of such circumstances. Of course, if I see the boiling water affect, I am going around and not tempting fate.
At the San Marcos, Tx Ice House dam (1973), it happened to me. The foam would not hold me up. I was trapped. Swimming to the bottom and kicking toward the downstream side was the only way out. They have since rebuilt the dam.
Second this. These concepts were taught to me early on when i started whitewater kayaking. With even a basic understanding of river reading, your ability to make safe decisions on the water is greatly increased. Having friends who know rescue techniques (throw bags and such), completely eliminate these kinds of accidents.
@abc The skirt is what keeps the kayak tied to your body - in order to escape you need to untie it to release your body.
It’s called a spray skirt. Trust me, if you paddle a river, you need a spray skirt. It fits snuggly around the waist & the bottom fits around the cockpit of the boat.
This is really well done. Very detailed, thorough, and clear. I felt that the part around 13:45 was particularly useful in pointing out indicators of dangerous hydraulics. Thank you for sharing this, and providing the opportunity for the boating community to educate ourselves.
my brother in law is a fireman in Harrisburg pa where one of these little deadly waterfalls are on the Susquehanna River. He said if someone dies in one, they won't recover the body because of the risk. They have to wait until it decides to spit it out.
(s)AINT Cyanide Ah, Harrisburg is home of the Dock Street Dam. A 1994 news report claims that in the previous 30 year period the dam claimed 17 lives.
Gun Jew, I live by Falls pa and I have to say, the Susquehanna river is not to be messed with. I say if almost gained 100 feet of water
Ed Kern although natural in origin, have you looked at the whirlpool rapids near Niagara Falls?
Here in the uk we tie a line and have an inflatable length of hose that we can feed along the hole, we can feed a firefighter across the base of the structure and have double failsafe plans for protection. In the event of any situation extraction can be made via any bank
This happens on the Bull in south carolina all the time. There's a nasty little terminal hole there that has claimed several lives this year alone.
This is very impressive and clear research, and beautifully presented.
Because of people taking time to put out good info like this , I am convinced it has helped keep me safer in my small boat on a large local river with such structures present.
Thank you
This was very informative and very interesting and well presented. A shortened version should be used to teach up and coming swimmers, or anyone going boating/ kayaking as this is important information. As you mentioned, public education is a good method. Of course restricting access and altering these dangerous channels should also be pursued. You guys are doing great work, engineering and improving public safety. Hope your research is successful as many lives would be saved.
Great video. Hydrolic jumps/holes occur frequently in rivers but don’t pose the same risk as dams do because they aren’t even across the entire rive and generally kayakers can exit the sides of the hole.
I am in my 60s and I now understand how lucky I am to be alive. I did a lot of stupid stuff when I was young. Thank you for your efforts and great video.
This taught me a lot about why objects get stuck over a waterfall, it taught me that such a scenario is called a hydraulic jump, and how to recognize the different types. Not only is this really cool, because it helps me understand why certain rapids are more dangerous than others, but it may just save my life someday.
Thank you for this informative and educational video.
This would definitely be in the scariest top 5 extreme ways to die, right next to getting buried in an avalanche. Can’t imagine what was going through those poor firefighters heads right before their boat got eaten by the void.
Escaping these is possible but hard and counter intuitive. Life jackets become death vests because they cause you to float up directly into the current that flows back and slams you down. You need to force yourself to stay at the bottom while moving away. Otherwise you’ll just be pulled back into the current. Stay below and move away. Keep the current above you. This can be difficult because it will shoot you up, when that happens you need to swim as hard as possible down and away. You can improve your odds, but you’re still going to be at the mercy of the water.
Wonderful presentation! Those planned modified flip lips would be more easily damaged by debris going over the falls and would have to be designed more robustly.
As someone trying to get into electrical engineering, this teaching style is amazing. Might not be my passion, but it was engaging, interesting, and effective. Is there anyone who teaches like this for EE?
When I was young I spent time in NE Colorado, we used to go swimming and tubing in the canals and go down the drops and hang out in the turbulent water there. Seemed to depend how deep/fast it was as to the best way to handle it if you got caught. Sometimes you could just go deep and get under it and pop up downstream. Sometimes swimming back upstream at 45 degrees while it was taking you back into the flow worked. I dunno...my grandpa was an expert swimmer and always told me whatever happens in the water keep calm and try to work with the water, not fight it. I saw the one at 5:00 seemed to have vortex generators on the edge or something. Does that help or just help protect the bottom from scouring or something?
A brook local to me has a high-level sewer crossing at just below water-level. To protect the pipe, a concrete dam was moulded over it with a steep rising face, narrow flat top and a shallow angle trailing face. At the foot of the trailing face there is a short distance of flat smooth concrete before a second much lower steep rise flat-top and steep trailing face moulded dam. I have noticed that at flow-rates from flood to nearly dry the circulating current is retained in a narrow pool at shallow depth, fixed distance within the confines of the structure between the two dams. There the bubbles are released, with very little air entrainment afterwards. All circulation is kept within that relatively shallow area and there is smooth flow with no scour afterwards. As kids, we used to play in and on the dam with no problems or fear of under-tow.
As a layman I found much entertainment and educational value in this matter-of-fact academic video presentation.
I wish more documentary and educational content were still made this way but since video delivery technologies became widely accessible in the mid-90s many production studios influenced control of the market by dictating specific format changes to ensure maximum return from the unproven technology shift of the day. Unfortunately the format changes initially were appealing but quickly proved to be regressive by 'glossing-up' and 'dumbing-down' style content. The format change has contributed somewhat to the demise of independent critical thinking as a cultural byproduct regardless of education background and nowadays we see larger and larger groups engaged in conspiracy theory logic(!) due largely to what they see as presentation of factual information.
In this age of global information exchange it is ironic that the emphasis on qualitative value of educational content has given way to one of entertainment and presentation value. Now we see this trend more and more in news media, particularly mainstream. Education can be attractive and appeal to a mass audience but only as docudrama storytelling, thereby rendering it moot.
Anyway, thanks for the informative video; I now know how to avoid drowning in a low head dam.
Edit: but more importantly I know why it happens...
Great video. I actually came across this video several years ago. I think about it any time I use the kitchen sink. This was on par with stuff you'd see on practical engineering. Maybe better since it's longer and goes into greater detail on the subject. Which I know is a turn off for some, but I prefer it.
Nothing\ I’ll never use a sink the same way again lol
I kayak every week on a low head dam....or as we call them in the UK, a weir. This presentation has, in my opinion, set an Industry standard for others in this field to follow !!! Where we paddle, (Lucy's Mill Weir, Stratford upon Avon) we have the additional problem of an adjacent sluice, which, when open, can greatly alter the wave characteristic of the weir. The best advice, as always, for the boater is...WHEN IN DOUBT DON'T !! Thanks for a great video, Brad, Moreton-in-Marsh, UK https://youtu.be/JI3sknnvOZ4
Thank you. Now I have a 100% higher chance not to die in these things, simply cuz I now know about it.
Also 14:15 never thought of that gassy foam situation!!! Holy crap!!! Before this video I wouldn't have seen the clear obvious points that make this spot a death trap!
10/10 educational video. Just imagine we'd learn stuff in school through such videos instead of random crazy boomer teachers lol ez A+
just came across this video, I am preparing a water safety course for a search and rescue team, great information and video clips, makes understanding easier. I have been a river kayaker for 40 years so do have experience in low head dams.
I started kayaking quite young. There was such a dam in the river a few hundred meters below the quiet place we were learning. One of the first thing they teach us was "don't ever think to go there!". And they shown us why. I kayaked several more years, and at a point I was able to quite properly "read" a river, where one could go through where not, where it would be delicate, etc.
I quit quite a long time ago, and certainly lost a lot, but that kind of beast I spot immediately.
Several are very nasty: but from some whiteness of the water under the surface, they look very innocent, sometimes just 1 or 2 feet tall, very smooth water surface (only a bit fast)... But disappearing under the surface abruptly at the bottom. One can pass with a kayak if straight without noticing, but if the boat has an angle, of if there is a fall, then, it gonna be hard to get out.
I was always told that if taken in such thing, to remove the life jacket, and swim to the bottom then go away straight. It may work from the current streams on the schematics, but I never had to try nor anybody I know, better said than done...
Brilliant presentation. Congratulations. I have been dealing with flood-water channels and I find it worrying how much people do not know about fluid dynamics. I would suggest that people should know when water is translated and when water is circulated as that is what it is all about. To minimise the study I would suggest that people would learn what happens in fluids moving in pipes or channels where there are quick changes in pipe sections or square diverging or converging sections. In both cases, zones of translation and circulation occurs and this many be extended to understand open channels where air can be sucked in as shown in this video. Really all these dynamics occur in boats and planes and birds around the wings where the tips and the flaps and the slats cause the air to circulate and translate through going from high to lower pressures. Life can be saved if such dynamic functions can be learnt . In the case of water, our vision many help but in the case of air dynamics, one needs to know.
The other day I saw a video of a light super-fast car overtaking a fast truck with a large trailer behind it. The driver of the super-fast light car was doing very well till he came beside the cabin of the truck where there was a heavy lateral flow of air being displayed by the truck . When this lateral slipstream caught the super-car, it was diverted to the crash barrier and the result was fatal. The truck was not even touched. If that super- sport- racing- light-car driver knew his fluid dynamics, he would have saved his own life, simply by knowing how to slow down at the right position and use his steering wheel to counteract the lateral force due to the " wind the truck created. Thanks for this video.
Interesting anecdote but I'm not sure that most people wouldn't be thinking about fluid dynamics when driving a car in a highway. Nor would people be clear headed enough to think about it when they are drowning. This knowledge is useful to avoid dangerous situations well before it actually happens rather than actively counteract them as the situation develops.
Very interesting. I've always known about this behavior from personal experience, but never really understood why it only happens in certain areas, and I didn't know what it's called... UNTIL NOW! Thank you, great presentation!
1. I appriciated the presantation a lot. Theory, lab and practise where really complimenting each other to educate while holding the attention of the viewer.
2. Education can go a long way. Although I'm interested in everything outdoors and have a degree in geography, none of my family members had any interest of education in outdoor topics. YET even as a little kid I got educated about the danger of dams and that you should never ever be stupide enough to jump down a dann or go swimming anyway near it, because at the bottom an undercurrent forms that even the strongest swimmer can't escape. So naturally when I started kayaking, seeing a damn, I climb the fuck out of the boat and carry the heavy ass boat and luggage around. Everyone in the region does it. It is common knowledge. No one would be stupide enough to go through it.
Very interesting. Here in France we also have a huge lot of "case C" waterfalls at artifical dams. As a white water kayaker and freestyler, I wish all these could be turned into case A or B ones, simply by reducing the slope of the fall. For public safety, and for some freestyle fun :) I used to think (dream) that if all these dams were built to be nice freestyle spots in the first place, then freestyle kayaking could really develop as a very popular sport, eliminating a lot of hasards along the way.
FS kayakers use to travel hundred of km to find a nice spot, when better dam design could create those everywhere in the country.
Get all the kayakers together to pay for it.
Hi This is well done and I commend you for working on a very dangerous construct of man. I have thought a lot on this subject and I think there may be a simple solution. Please experiment with building the dam at an angle to the river flow. Since it's so difficult to control the possibility of a dangerous hydraulic forming at some levels of downstream water or over time with deposits and changes in the bottom the angled dam will carry trapped people to shore naturally. This can also be done with an arrow shape. The point of the arrow in the middle of the river and the 2 angles traveling up river towards the shore. If the shore ends in a wall then it would need to be stepped to allow exit for victims. I was a whitewater kayaker for many years and often pondered this dilemma. No one ever gets trapped in an angled hydraulic because it takes you to the edge of the river where then hydraulic ends at the shore.
Read an article of a family that drowned from what was described as a hydraulic like dam and I was confused. Video was visually informative and helped me to decide to stay away from large bodies of water all together
thats a good dam presentation
You could even say it was a dam good presentation.
Damn
What a dam good pun
Is this a god dam?
Weir in agreement
The best part of the whole presentation is when u use Ken as your lab mice..lol...I like how u narrate Ken's vacation in different jumps..haha..A++ for that. It really presents very closely how distressful a person would be if caught in Case C jump. Even ken's hands and legs went haywire! This is really educational and it creates awareness to a lot of people. Many people drown in a river as they don't how the current works and how dangerous it can be. I think you should cut out that part and make it a safety awareness video. It will save a lot of life.
Ron Dye Channel - 2016-11-03
I can attest, as a 17 yr. old strong swimmer wearing floatation, I went over a 18" drop created by a gravel dredge line on the Clackamas River in Oregon. I was continually dragged back to the water drop line and pinned on the river bottom. I could crawl forward underwater toward the drop but not against it. Thrusting myself upward I could get a few breaths before once again being dragged under. Once totally exhausted I shed the life jacket to attempt to swim out, only to be dragged to the bottom again. I blacked out but was thrust out of the undertow because I no longer had the additional flotation. Incredible I survived.
Ron Dye Channel - 2017-01-16
Possibly, and I am the proof of a parallel universe. In fact after I passed out I saw everyone standing around grieving at my funeral. Also the little blip in the local paper about a teens drowning on Clackamas River. You decide.
A.J. Deutsch - 2017-02-04
Ron Dye Channel, wow, also have you ever had a dream like about a tree house and has 100% sure it's real then go check and it isn't there. I recently had a dream that I had maybe 9 years ago. I literally went outside to check if the house inside a tree was there. It wasn't. Kinda proof that only in dreams can you access a different universe. I don't know I gotta do my reasearch
Advanced Nutrition Inc - 2017-04-06
how would anyone have proof they ALMOST drowned some time ago?? If he died we would have not heard the story, unless we were a local around that area that that time.
tolga1cool - 2017-04-11
Johan sigurdson You do realise that what you ask for is stupid? If you don't believe him then go ahead and don't. but how should he be able to prove that?