Impressive presentation on the dangers of low head dams

This just popped up in my YouTube recommendations.

Great presentation on the dangers of seemingly small dams


Very interesting. Of course there is another option ,. Remove the low head dam.

Many of them on the Cedar River in Iowa and the Chattahoochee at GA/AL border that were made to power mills before reliable electrical power. They serve little use. Most of the mills are gone. The dams are often silted up behind the dam.

Remove them like they did in Columbus GA and create a whitewater park.

Former employer…

Or, if the empoundment is necessary to control the river drop, do as they do in the UK and build an extended weir in place of a low head dam. I kayaked the Rivers Derwent and Rye in Yorkshire with the local paddling club when I was there in 2017 and we just slid down the weirs, which are built with a recess down the middle that creates a flow tongue specifically to enable canoes and kayaks to pass down. The gentle grade of a weir means there is no deep deadly circulating hydraulic at the base. Photos are of two weirs on the Derwent. The Brits are far more apt than we Yanks to consider their citizen’s recreational opportunities when they do public works and infrastructure projects. Just down stream from the taller weir was a 300 year old grain mill that has been restored and converted to a hydro power generating station with a regular turbine and 3 Archimedes screws. Besides providing power for 3000 homes, the station also functions as a community education center with gardens and a picnic park and they built a permanent whitewater slalom course into the rapids in the millrace outflow.



That would be awesome, but the first thing that comes to mind in modern America is Liability. Which is quite sad. Public projects like that are incredibly rare

I recall something like that perhaps on Fall Creek in Indiana. It was low head and low drop. Maybe 1-3 ft. But it’s been decades since .

Nice presentation. Thank you.
For quite a while I volunteered for a group that had as one of its three main objectives the removal of low head dams that were no longer serving a useful function. Most had been built to run mills, were later upgraded to produce electricity on a municipal scale and then just sat there when power from the grid became cheap enough to make the dams unnecessary. Many weren’t overflow dams, though some were and they present all the hazards the presentation refers to. It is often possible to convince communities that removal is a reasonable course when following scheduled safety inspections the dams fail to meet standards. Its often cheaper to remove a dam than repair it, and is therefore an attractive option with local taxpayers. There’s always a percentage who paid a premium for “waterfront property” and don’t want to lose their waterfront, but in many cases that waterfront is less attractive than it once was, having filled with silt, carp and mosquito breeding habitat.
When I was a kid I lived in (what was then) rural Illinois. (Can’t help it - none of us choose the place of our birth… and its been more that 40 yrs since I moved north with NO regrets.)
On the river near where I lived back then there was a series of low head overflow dams, built to stabilize the water levels on the river and allow residential development along sections of the river along the bank. I can just barely recall the discussions of their construction - I was quite young.
One such overflow dam, the one nearest where I lived, killed 22 people by drowning over the years, I’m told. Many were fishermen wading up to the boil line from the downstream shallows, though there were more than a few paddlers especially in more recent years. (The river was badly polluted back when I was a kid and not so many people were as willing to paddle it as I was, so there were fewer paddling casualties. What did I know? I was a kid. And we paddle the water we got.) I recall portaging around the dam in spring and seeing whole trees spinning at its base, and they were still there spinning in autumn. There’s a lesson in that to those who care to observe and think a bit about it. I haven’t paddled that river since '78 but I do have a few old friends that I keep in touch with and one told me about this development at that very dam.

I’ve driven past and looked at it twice since then while on the way to somewhere else and without a boat loaded. Its short, not a bit like the Ozarks or northern Wisconsin whitewater, has a little whiff of gentrification about it. (If my childhood memory is correct, the rental facilities and access trails are where the grain elevator once stood.)

But that is a GREAT way to solve the problem the dam posed. Somebodys down there did something right, and kudos to them for it. As you might guess, there’s just not a lot of white water in Illinois. They’ve created quite a valuable resource with that project. Credit where its due.

PS: Here’s a better overview of what was done. Could be done with many other dams elsewhere, I’d imagine.

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Dams scare me. We lost a kayaker to a nearby dam on January 1st of this year.

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Two 20 something young women in their brand new big box rec boats died here in Pittsburgh 2 summers ago after ignoring numerous warning signs and buoys ahead of a low head dam on the mighty Ohio. They took smilling selfies and posted to their social media just seconds before the tragedy. Not wearing pfd’s of course, not that those could have saved them but might have shaved a few days off how many it took to find one of the bodies that got flushed out of the hydraulics, which are a churning macerator of scrap steel and big strainers. River rescue had to extract the other from the maelstrom, reportedly in pretty rough shape.

Sometimes the dangers of low head dams are not apparent and fatalities don’t necessarily occur as a result of attempting to run or swim them. Elkhorn Creek near Frankfort, KY is a popular Class I-II+ whitewater run that is often used by paddlers who are relative novices to whitewater. Unfortunately, there is a low head spill over dam owned by the Old Grand Dad distillery on that stream which wants to preserve it so that the impounded water can be used for fire control. At the very lip of that dam on the river left side there is a very small one-boat concrete landing pad. From there it is possible to carry over a rock scramble and put-in at an eddy below the boil line created by the dam. The carry is over big rocks so one is not inclined to carry further than necessary. The banks of the stream are very steep there and covered with loose rock, so portaging around the dam by taking out higher up and putting back in farther downstream is not only not practical, it could even be dangerous.

The problem is that there is recirculation in this eddy that feeds back into the hydraulic above the boil line. That recirculation is rather subtle and might not be apparent to a relatively inexperienced boater. And as water flow increases, the boil line of the main hydraulic tends to move downstream. I have frequently seen kayakers slide their boats into the eddy and mess around fitting their spray skirts completely oblivious to the fact that the recirculation was slowly moving their boat back up the eddy toward the main hydraulic. I had frequently thought that it was just a matter of time before someone got slowly sucked back up into the hydraulic unawares.

Just under two years ago it happened just that way when a 35 year old kayaker, who does not sound as if he was completely inexperienced, portaged around the dam and put in on the eddy too close to the boil line. He wound up in the hydraulic. He was thrown a rope but could not hold on and his body was later recovered downstream.

thanks for posting. Lowhead dams are common in the West due to irrigation diversions. They are usually vertical and perfect drowning machines. Their hydraulics create a perfect reversal wave that often contain logs and woody debris.

Some years ago on the upper Truckee River I cautioned a friend not to run the diversion dam on our route. He and his 3 friends and a 12 pack ran the dam, tacoed their raft, filled with water and were getting pounded by the logs in the reversal. We eventually pulled them all to safety from shore. Three people quit the sport on the spot and never went rafting again. They walked back to the take out.

The Sleeper’s Keeper

“No one ever paddles same river twice.”
Well I say to myself, “Dam! That’s good advice.”
For no matter how littlest drop often bore your surmisin’,
unseen changes are always churning underfoot of event horizon.


I recently took a swiftwater rescue course in NY. We were shown the following video as a lesson in what NOT to do. The first boat was there to recover the body of a rescuer who had capsized and whose body had been stuck there since the day before. Before it was done, 3 rescuers died.

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That was hard to watch.

Watching people run them in real life is even harder than watching a video.
Don’t do it.

Maybe I am a bit dense, but what was their plan for NOT being dragged towards the dam?

It would be easy to say that there was no plan, but that is not a realistic assumption. The foam on the surface was obviously floating towards the dam, and the very problem, which they were there to solve, was caused exactly by that current phenomenon. So they would have been aware of the current direction and the need for a plan.

Yes, the video is almost sickening to watch. The boil line and current reversal are clearly evident in the video and whatever type of grapple pole was used was nowhere near long enough to reach from downstream of the boil line to the actual hydraulic.

As soon as the boat passed the boil line it was predictably accelerated into the hydraulic. It may not have made any difference but a back up boat with some individuals equipped with throw ropes who knew how to use them might possibly have allowed rescue of one or more firefighters.

My thought was “why not go in with the ropes already attached?”. If you know there is a high risk that you need to be pulled out, there is no need to wait for someone to throw you a rope.

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The “rescuers” were firefighters with no formal training in boat rescue training, especially in such a dangerous location. A case of inexperience and ignorance more than anything else.That type of training probably did not even exist in 1975 at the time of the incident. That’s why I took the training recently.