Looks like a Low Head dam strikes again

I sadly write this and loss of life is catastrophic always.

I grew up in and age where my father would tell me to do my “Due Diligence” and then offer me his knowledge and wisdom on whatever I was about to undertake and lastly tell me he wouldn’t be around forever and it was important I think ahead on my own.

For some reason and I hope it is just me getting old and it really isn’t happening, but I feel each generation is losing self reliance and expecting the world to totally guide them along safely. Cars hit the brake for you and soon will drive you. Everything you put in your mouth has been tested and prepared in advance. There is becoming a lesser and lesser degree of self-awareness IMO.

In an attempt to make everything without risk in some ways people are unaware of risk. Nowhere is it as apparent as watercrafts. Any kid with 5 minutes of training can run a jet ski it seems. I had a family member that bought a very powerful jet ski and she asked me who should be allowed to ride it? I told her first rule if it were mine would be read the book that came with it. Second rule is wearing a PFD. Third rule is go out into the cove behind her dock and jump off it and show her you can get back on. To her and their surprise a couple of her grown kids couldn’t get back on it.

This is a tragedy but the worst kind I can think of. One that was 100% avoidable.


A local river called the Gunpowder in MD is a favorite tubing spot. When we have flash flooding, a lot of debris gets carried into the river, like grills, metal drums . . . Tubers use the waterways with blind faith. I’m sure they don’t see any danger, because 10s or 100s of thousands have used it to escape the summer heat. My view is you would have to be a fool to float that river, because the banks constantly shift slightly and that could expose sharp rusty hazards.
The limited number of injuries proves I’m overreacting, but that doesn’t mean wrong. I repeat: we have a rightbto offer an opinion. But no right to expect anyone to ask for our consent. No example I can think of will change that, unless you show a statute, but people breaks laws all the time. Can’t do anything more than lock them up. I hope the water police don’t arrest me one day because. I’m too far from shore. You have one life, it’s up to you to make judgements about how that works. Look at the picture from the Fjord. I’m not going to tell them to get out of there. It’s what they do, and I’m darn certain they know the risks. I once went out in fog with 1/2 mile visibility. I’ll listen to recommendations for handling fog, but don’t expect me to reply about “What was I thinking!” Thinking? Greatest trip I ever took. If me own sweet mother said, don’t you go out there Jyak, I’d say we’ll talk about it when I get back. Can’t say no more. How do you find that duck pond?

“I” stay clear of low dams. Does anyone think they actually thought that was a water feature to be explored. By the way, the info about how to get out of that water trap is very much appreciated.

Escaping a low head dam that creates a strong hydraulic all the way across the stream bed is very difficult because there is no “side exit” that a swimmer can work their way to. The best chance of escape is probably if someone is on hand to throw you a rope and you are able to catch and hang on to it. But there have been many recorded instances in which the person getting recirculated was too disoriented to catch a rope or too weak to hang on to it. There is also the risk that a swimmer getting recirculated will get wrapped up in any excess rope. But it the swimmer can hang onto it, a rope potentially allows a rescuer to pull the swimmer out in a downstream direction.

If you are caught in a hydraulic with no safe side exit alone, the conventional “wisdom” was to try to go as deep as possible at the moment you are pushed under by the recirculation as the water exiting the hydraulic is usually at the very bottom of the stream bed. This is one instance in which a PFD can actually work against a swimmer if it prevents the swimmer from getting to the bottom of the channel. Another piece of frequently dispensed advise was to “make shapes” with your arms and legs. A circular object like a swimmer who “balls up” gets recirculated more easily than one with a more complex, elongated shape.

The majority of people who get trapped in a hydraulic created by a low head dam do so through ignorance thinking they can run them because they often look relatively innocent, or they simply don’t know that they are there.

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Powerful powerful observation - due diligence . . . generation loosing self reliance . . . everything has a safety warning.

Is that crazy: no warning on tide pods telling everyone not to eat them, no warning on lemon scented dish detergent to not use it for lemonsaide (I couldn’t get past the creamy head to even taste it, but the bubbles burned my nose, huffing cinnamon does have hazards. But in small doses it must be a rush. Just ban big gulps and limit purchases to 16 oz and one per customer. Eliminate salt. Yet we invent reasons to keep border open for the illegal Fentenol trade and opiates from the other places. Save me. Wonder what a safe dose is for a habit forming narcotic. Never mind. I think I figured it out.

I saw a rescue video of emergency crew’s attempting to rescue power boat passengers. It was heart wrenching. Not so much for the victims as much as watching the rescuers get trapped.

I put errant behavior in perspective. Danger to self and danger to others. Danger to self is a personal decision and totally an individuals prerogative unless you have custodial relationship (for example: your child). If you perish through accident or gross negligence, it’s not my business. If the danger to rescuers is nothing more than recovering your body, you can take the risk. Put another at risk. You better think twice.

Very good, informed explanation of self rescue.

IN the UK they have weirs instead of low head dams on many rivers. Much better solution to level changes, and I wonder what the cost differential is. I got to encounter them on two of the rivers I paddled with the local canoe and kayak club during my visit to Yorkshire a few years ago. They are constructed with a notch on one side or the middle through which a boater can slip down the low angle ramp and easily shoot through the very low turbulence at the base. We did have to get out and remove a large tree branch that had gotten hung up in the notch at one but that was easy. On one of the outings I was in my folding kayak and knew the soft shell might drag or hang up on the concrete in the shallow chute, so I just pulled out ahead of the drop and portaged. But I was able to walk out along the base of the weir only a few feet from where it leveled out into the river and relaunch.


Some dams now have weirs or run outs for safe passage by boats. The S Platte R in Denver has some. Some day all low head dams will have them.

I have pulled people out the hydraulics at the base of low head dams with throw ropes a couple of times. People tend to get panicky when they realize they are in a perfect reversal. There is often wood debris in the hydraulic thumping them and their boat. Some people have quit the sport on the spot.

I found it interesting that virtually all the paddling club folks there in Yorkshire preferred solo or tandem canoes and whitewater/squirt boats. They had their own boat house and dock and of the dozens of craft I saw on the racks, there was not a single rec style kayak and only a handful of sea kayaks. even though the town was only about an hour’s drive to the North Sea coast.

Though we were launching that day shown below on the narrow, meandering and shallow River Rye, some of the paddlers chose to wear helmets because our takeout downstream was aat Howsham Mill, where the restoration project 5 years earlier had converted a 18th century grain mill to a hydroelectric generation station (a turbine in the diverted flow plus 2 Archimedes screws) and the design included creating a permanent whitewater course built into the millrace outflow so paddlers could play in it.

Video here showing the Howsham weir and how nice it is for paddlers.

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I guess great if you know enough to use it.

The problem with attempting to swim along the bottom to get out of a low head dam hydraulic is, besides the PFD problem, the swimmer must remain oriented enough to know which way to swim and at the same time be able to swim underwater far enough to escape the strong surface flow back into the dam. There are multiple instances of boats going to rescue a swimmer being caught in the reverse flow only to be capsized at the dam resulting in multiple casualties.

If you tried to paddle over the lip of the weir instead of the chutes you would just hang your boat up on it and scrape the crap out of it – the volume washing over it is too thin to float you down. The locations of the weir channels are well marked upstream and the current is going to draw you to those tongues.

Weirs are so common in the UK apparently everybody knows where they are. They also have small dams on their many canals with self-service locks but the ones I saw were not low heads.

Dago: 75% of the 3,000 dams in my state (Pennsylvania are “blind” lowheads. Best believe anyone who paddles on a river of any size here is going to run across (and possible over) them. Virtually every coal fired power plant is squatting beside one, for example. They are gradually removing some of them but that will take decades…

We lose people going over them every year including powerboats and even a tugboat, especially here in Pittsburgh where 3 major rivers that cut through canyons combine to become a Mississippi feeder (the Ohio). From 5 to 10 miles up or downriver from downtown Pittsburgh are major lowheads with locks. Paddlers , like commercial traffic, can signal the lock tenders to use the locks. It is just inattention that causes people to get swept over the dams or sucked into the recirculation from boating too close downstream.

How does everyone think large wing dams like the ones on the Mississippi river compare to low head dams?

Mississippi pool 10/11 paddler here. The wing dams are essentially “no head dams” with the water dropping a few inches at most over several feet as it crosses. They do produce some flow reversal, and could probably flip an inexperienced paddler in a WW or sea kayak not paying attention, but do not have the energy to roll a swimmer in a PFD the way a low head dam can. To a swimmer without a PFD, or a non-swimmer in a PFD they could be lethal.

I don’t mean the dams on the upper river, I’m talking about the long wing dams on the lower half of the river that are nearly a mile long in some spots. Specifically how those can range in danger when the water level going over them varies from nothing to feet.

Pbailey is right about the wing dams. There is very little elevation drop on them, and little to no hydraulic reversals behind them. Since they don’t span the river, there won’t ever be much of an elevation drop. They can be brutal on boats and would beat up swimmers because they are essentially long rock walls protruding out into the current. I don’t have much experience with them on the Mississippi, but have lots of miles on the lower Missouri River, where they are basically the same.

They have started putting in fish weirs around here as an alternative to traditional fish ladders or complete dam removal, which can disturb upstream wetlands. Basically you build a huge rock ramp with gradually ascending stone weirs, which serve like terraced steps. Pools between the steps give fish a place to rest on their way upstream. Gaps in the weirs create channels for water to flow and fish to swim, including the main current down the middle that forms a nice channel for paddlers. They have done two so far on the Pawcatuck River in RI

Kenyon DamJim C running the Kenyon Dam

Bradford DamIMGP1739

The dam is still at the top. They just build the rock ramps below it. Seems like a great solution - somewhat natural looking and fun to paddle. Unfortunately, it is still pretty expensive - the Bradford Dam restoration cost $2M.

Lots of dams around here, but we don’t seem to have the problem with people trying to paddle or float through them that you do in other parts of the country. The dams trend to have pretty good drops, not the 3-4 foot drops that I think of when I picture a low head dam. Maybe that is it, or maybe I am not all that familiar with low head dams.

Around here river-wide ledges are also a big issue. This one on the North Branch of the Pawtuxet is particularly nasty…

The line is river left of the twigs that you can see in the lower right of the picture. I saw a guy in a Mamba try to run this through the middle. The boat stalled in the aerated water and he eventually flipped. The boat got sucked down and never came back up - we assume it got stuck in debris. Fortunately the paddler flushed out pretty quickly. He said he used his paddle to push off the face of the ledge before getting sucked in - very, very lucky. To be honest, that is the last time that I ran that section of the river.

Gives me the creeps. As a relative novice, I’ve had two LHD encounters. One on the (Texas) Colorado and one on the (Texas) Little River. Neither were signposted in any way. The one on the Little River, near Cameron, terminated the trip as there was just no way around it. I spotted it when a heron took off from the bank ahead and flew “under the water” - hmmm, didn’t know herons could fly under water! In both cases I was fortunate that the flow was slow enough to easily back up. This lead me to Youtube where I learned how terrifying these things can be. In both cases the old Southwest Paddler website made no mention, so now part of my prep is a full survey of the route on Google Maps/Earth, although I’m aware this may not be totally infallible (eg. stretches with lots of tree cover). I’m very glad I now feel forewarned and forearmed. Casual folks out for an afternoon tubing would not stand much chance.

Here’s the one on the Colorado

IMG_2917 (1)

The hydraulic in your above post appears to be navigable.
Some hard paddling before the drop would allow enough momentum to go through the reversal. This looks very similar to a lot of ledges that occur naturally on rivers everywhere. The angle of the drop is not anywhere near vertical which is why it is runnable.

Alternatively if you don’t like the looks of it. You can portage around it.

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It would be helpful to see a video but yes, I agree that looks more like a potential stopper wave than a hydraulic. Water flowing over a slide of 45 degrees or less might kick up a good size wave but that is not at all as bad as the reversal current of a true hydraulic.

A wave like that might well stop your boat and turn it if you don’t have sufficient momentum, but it is unlikely to be a “keeper”.

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