How big is the low head dam problem?

I’ve done a little bit of kayaking in the distant past, and since I have plenty of nice rivers and some lakes near me here in the mid Atlantic, I’d like to do more paddling and maybe some tubing in the future.

I heard about the tubing incident at the low head dam last year in North Carolina where five people drowned, and my research so far suggests that there are a lot of low head dams in the US. I’ve watched some videos and I understand why these dams are dangerous. But I’m wondering how big this low head dam problem is. Specifically:

  • Roughly how many low head dams are there in the US?

  • Roughly what percentage of these dams have no signs at all?

  • Roughly what percentage of these dams have signs, but they’re not good signs?

  • Roughly what percentage of these dams have adequate signs?

  • Roughly what percentage of these dams have buoys?

  • Roughly what percentage of these dams have portages?

I know there’s no database from which we can answer these questions, but I’d appreciate everyone’s estimates. I’m especially interested in the situation in Pennsylvania, Maryland, Virginia, North Carolina, and South Carolina.

From experience, there are all sorts of dams both small and large that are in various stages of disrepair, ranging from low head to full size mill dams, to old wicket lock dams all over the country. Very few are properly signed or marked unless they are part of a paddle trail or a park or something and same goes for portage trails. Getting the really bad ones removed is a tall order as no one wants to pay for it. Lots were build by local municipalities to divert drinking water, others by the Corps of Engineers for navigation and some by private companies to power mills. Many are privately owned as well. it is a real problem across the country.

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Can’t answer your questions with any degree of accuracy, but I can say from personal experience that there are many, many low head dams on US streams. These vary a lot in height and lethality. The great majority that I have encountered have no buoys and most do not have signs.

In terms of how hard they are to carry around, they vary from easy, to quite difficult, to dangerous. Most had no provision for a landing spot or carry around when they were constructed.

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There are an extremely large number in the North East. The problem is there is not a given agency whose job it is to warn about hydraulic hazards on inland rivers, streams and canals. Lots of these places the people who built them many years ago did not anticipate tubers, inflatable kayaks, SUP paddle boards, and kayaks trying to run complete sections with no knowledge of hazards. And finally the hazard changes with different water flow. A dam may be safe at low water flows but local flash flooding can turn them into death traps for inexperienced paddlers or paddlers who do not know the hazard is there. Your best bet is to check river and paddling guides for where you want to paddle, and inquire locally at paddle shops and kayak clubs, and visually inspect your entire route before you put in. Personal experience in Eastern PA, NJ, and VA was there were a lot of dangerous dams.

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The next one, from Binghamton NY is a case study in all that can go wrong without proper understanding and equipment. It is used as a class training video to would be swift water rescuers.

https://imgur.com/gallery/ZizOUie

A google search will find more.

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BIG

In many cases they look like a simple little drop to most people.

A quick Google search says there are more than 65,000 in the eastern US. Many states spend big $$$ trying to educate the public to the danger. As you said removing them is a problem of funds to to so.

I’m in southern New England, and there aren’t a lot of low-head dams around here. There are plenty of dams, but they are almost always big enough that you wouldn’t try to paddle over them intentionally. There are plenty of river-wide ledges around here, though, that can have the same effect if the water is at the right level. I saw this one eat a Mamba…

Kayak got sucked down and never came back up - must have gotten stuck in the debris down below. Fortunately the paddler didn’t get sucked into the recirculating current or it would have been a really bad trip…

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Low head dams are perfect reversals.
Avoid them always.

I wish that the small to medium ones could be replaces with weirs, such as are common in the UK. These extended low angle ramps perform the same function as a low head dam (creating a level upstream empoundment) but prevent the dangerous reversal turbulence at the base. They usually have channels built in that allow canoes and kayaks to slide down a shallow flume (works for fish too). I encountered several weirs during my 2017 paddling trip to Yorkshire. It’s even possible to walk up them at moderate flow.

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We are experiencing very high flows this spring/summer making these dams even more dangerous.

Do your research before floating an unknown river.

We have a couple of them in RI on the Pawcatuck River - this one replaced the Bradford Dam and cost $2M.

New Bradford Dam

It does have a channel down the middle for boaters = this is us running it.
https://vimeo.com/271000782

Here is another one at the old Kenyon Dam.

Kenyon Dam

Too bad they are so expensive to build.

I would be interested to know how the cost to build a weir compares to that of a low head dam at any given location.

The weirs we ran in the UK were mostly single tall low angle ramps with a central or side passage small craft flume. Only one was a multi-level as you’ve documented (much more fun to run and probably easier to construct).

Between removing the old dam, doing any environmental remediation and putting in the new fish weirs (essentially a long flat dam) it can be expensive. As I said above, the Bradford fish weirs cost over $2M. From what I can find, the smaller one in Kenyon cost over $1M. The preferred option is to just take the dam out all together like they did on the Pawcatuck at Lower Shannock Falls - even that cost around $1M.

Running Lower Shannock Falls - Jonathan

Just in little RI there are over 500 registered dams, most privately owned, many in pretty bad shape. Still, you are not going to get private owners to spend that kind of money. Most of the money for these projects came from federal infrastructure funds, which will be tough to get going forward. Projects would probably be even more expensive in other states where the rivers and dams are bigger. Across the country it would be billions and billions of dollars. This report estimates $64B.
https://damsafety.org/sites/default/files/Cost%20of%20Rehab%20Report-2016%20Update_1.pdf

I know of several lowheads that are supposed to be simply removed in PA due to decommisioning of smaller power plants for which they served as empoundments for cooling water. I believe the one at Shawville in Clearfield County, on the Susquehanna West Branch a mile upstream of my ex-boyfriend’s riverside acreage, is due for removal. I hope that goes through soon as that will eliminate a troublesome portage that used to limit our river trips.

My question on costs was how weirs compare with dams in NEW construction. Obviously, replacement of any infrastructure installation is never going to be cheap . I am a retired major projects estimator and PM but have only peripheral experience with civil and lock and dam costs.

There is little chance the low heads on our major rivers (like the trio of major Mississippi drainage feeders here that shape Pittsburgh) could ever be removed since they are necessary to create the depth stages for the major industrial shipping lanes and lock systems. So there will always be careless or reckless people who ignore the warning signs and barriers ahead of the deadly drops. And we will always have fatalities and fraught rescues.

We recently had a kayak and SUP rental concession open here half a mile upstream from a major lowhead dam and lock on the Allegheny River. I admit the location makes me nervous even though warnings are clear (and I will be shepherding a group trip through the locks next month).

Do any of you personally know someone who drowned at one of these low head dams? We can find news articles online about drowning incidents here and there in the US, but relative to the large number of these dams and the large number of people on the rivers, it seems like these drownings are relatively rare?

While I do not know personally anyone who has drowned at a low head dam, I do know of individuals who have drowned at low head dams on two rivers I have personally run. Both of these were on rivers fairly heavily used by paddlers.

Thankfully, both dams have now been removed.

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There are an annual average of about 4,000 unintentional drownings a year which comes to about 11 a day. There is also an annual average for nonfatal drownings of about 8,000 or 22 a day. Yes I had to look that up. That’s more than I thought, but not a lot in a nation of over 330,000,000. So drownings are rare in the overall population, but of course higher with those who spend time on the water. Now the subset of that population is going to also be very small that spend time on the water where low head dams are present.

Your question of how many personally know someone that drowned at a low head dam is indeed a small subset of drownings. Now the question is what is the subset of low head drownings to all drownings on an annual basis. The implication is that they are insignificant.

My question is have you ever tried to save, or was unable to try and save someone who was drowning that died. In that context I think most would rather not have a potential death trap that drowns people regardless of the rarity. How significant is it for the families of the deceased to know it could have been potentially avoided.

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I wouldn’t characterize potentially avoidable drowning deaths as insignificant, just trying to gauge the magnitude of the problem. Seems like just about everyone knows not to go near these dams or intentionally go over them?

When I was a kid and could hardly swim, I was playing around in the shallow end of a pool of our family friends. The deeper end of the pool kept tempting me, and the people who could swim made it look easy, so one day I decided to go a little into the deep end, tread water and work my way back to the shallow end, just so I could get a taste of the deep end. That plan didn’t work well, as I started drowning, and I was saved by a little girl (4 years younger me) who jumped in and pulled me out. So I was almost one of those unintentional drowning stats, though it would have been a result of my bad decision (and lack of adult supervision).

Some of the people who drown might be aware of the dangers but wind up going over the dams or get caught in the backwash of the hydraulic accidentally.

In one death that occurred within the past few years on Elkhorn Creek in Kentucky a kayaker drowned at a low head dam that has since been removed. He had portaged around the dam and put his boat back in the water a bit too close to the dam. Recirculation in the eddy funneled his boat into the hydraulic as he was paying attention to reattaching his spray skirt.

Another dam on the North Fork of the White River in Missouri, a long-standing mill dam that had been partially breached by flooding, a 13 year old girl drowned after she jumped in the water above the dam to try to help a friend who had accidentally fallen in the river. She got swept through the breach and entrapped by rebar.

Quite a few people have unintentionally gone over low head dams and drowned because they didn’t know they were there, or did not realize how close they were to them.

I include this incident because it took place at a place I have paddled hundreds of times. If I may describe. It is a dam with a smooth rounded spill over face. In the summer the water spills over maybe only one or two inches deep. The river normally is placid 60 to 200 cfs. The water slides over the face of the dam and enters the lower water, a vertical 7 or 8 feet, almost without a splash.

The canoe that day was portaged and had entered the lower stream. The two young men paddled upstream while waiting for the rest of the party to complete their portage. The concealed currents drew the canoe closer to the dam face and fairly rapidly, and when the moment of contact with the face of the dam the water filled the canoe, or half of it in one or two seconds, a 17 foot aluminum Grumman canoe snapped cleanly in half, two separate pieces in the next one second. The two young men caught in the rotary current would be sucked down and resurface over and over again. One adult leapt into the water to rescue. One youth was ejected by the current and one youth and the adult continued on the rotary submerge and surface until each wore out and drowned.
I came through the next day. The canoe was in two separate pieces 40 feet apart in 7 to 8 feet of water entirely visible. The river surface placid and flat, the water sliding over the dam absolutely flat, just a bubble zone at the base. ALL of the danger and current completely invisible. Just don’t get too close to the base of the dam.

Low head dams are dangerous both above and from below, they can look innocuous and serene, but that is the trap. They are deadly dangerous. I have canoed the Colorado and the Green and all of the rapids in them multiple times, and where I will with glee paddle a Class III or Class IV rapid in a canoe, low head dams scare the begeebers out of me.

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