Low Head Dams

I live in NW Ohio and we had plenty of low head dams on our rivers. I have always been pretty leery of them and for the most part portaged around them.



I’d like to see a show of hands from those of you with experience with these. Do you paddle over them? Does it just depend on the amount of drop? Around here they vary quite a bit in height and style.



I just didn’t know if I was being too paranoid.



Thanks,



Joe

Avoid them
They are very dangerous, but typically look benign.

definitely portage
It’s one of the top killers in the kayaking world. Scary stuff even though they look like an easy drop.

Yeah
We put in just beyond one (a little closer than was smart) a couple or so summers ago, when we were doing a long end-to end (car at each end) paddle on a local creek. It was September, and a dry one at that, so we got away with it. But it was apparent once we were in the boats that it wouldn’t have taken a huge change in the water volume to convert it into a dangerous situation. You really couldn’t read the water well from looking at it.



I second the motion - avoid them.

Death traps!
Beware as well of a long backwash when you put in below. If you do get caught and start being recirculated your only hope is staying alive long enough for someone to rescue you. That means breathing correctly. If you simply inhale every time your head comes up you will drown. Instead, exhale strongly. You will inhale automatically and the air in your lungs will contain more oxygen.

It’s Not "Paranoia…"
if the threat is real! As the kids would say, “Don’t mess, unless you want to get F’ed up!”



P-O-R-T-A-G-E



sing

actually there should be more awareness
if anything about low head damns. In the whitewater world strainers, low head dams, and undercuts strike fear in the hearts of all boaters. All of them equal a good chance of death which is why whitewater boaters such as myself, sing, and Dr. Disco are so quick to respond. For the recreation river runner, these little drops seem harmless enough until they get caught in the infinitely circulating hole. :frowning:

Drowning machine
http://www.dnr.state.oh.us/watercraft/facts/dams.htm



http://www.boatingsidekicks.com/kidsknow/INWATER/drowningmach.htm



http://sites.state.pa.us/PA_Exec/Fish_Boat/lowhd1.htm



http://files.dnr.state.mn.us/education_safety/safety/boatwater/drowningmachine.pdf


“The most dangerous thing about low…
…head dams is that they don’t look dangerous.”

Somebody on boatertalk posted.



And I suspect that is correct.



I stood on a shore looking at a low head that I

knew to be a killer, and even though I KNEW for

certain that it was a death trap, I swear it

looked runnable.



It just did not look that dangerous.


in IA
http://www.iowawhitewater.org/reconnect.html

and

http://www.iowawhitewater.org/inthepress.html



Is a program in IA that is helping to remove low-head dams.

great to hear. hopefully more states
follow suit. I’m glad I live in Wisconsin which is one of the leaders of dam removal. Unfortunately we had to suffer several dam related deaths before this process began and there are still many left.

Venturing where angels fear to tread.
The general rule for low head dams is portage. But there are some exceptions that can be run by people who know the particular dam and situation. We have one river in our area that has 12"-18" retention walls that are riverwide. Technically, they are dams, but the drop is shallow and into shallow water. There are no rollers or deep undercuts. Some of the bigger ones have breaks with nice tongues that we run. The consequences on these ‘dams’ are not significant.



We also have a dam on one rive with an 18" drop that is a killer. It drops into a pool with an undercut and a keeper. Deadly. So knowing what you’re dealing with is critical.


Additional input …

– Last Updated: Feb-21-05 6:29 PM EST –

Rescues from the bottom of low head dams can be extremely difficult/life threatening for rescue personnel.
A hydraulic below a low head dam is very capable of drowning you, with or without a pfd's.
The water in hydraulics is usually highly aerated; in some cases a pfd effectiveness will be severely diminished.
At the bottom of many low head dams there is often rebar, holes, undercut rocks, jagged concrete, boulders, and varied dangerous pieces of debris such as rope, logs, old tires, fishing line, etc.
Hydraulic current can be violent; victims have been impaled on rebar, and tree limbs.
There are always associated risks; hypothermia, entrapment, trauma, and being knocked unconcious to name a few.
Make a "well reasoned" decision; avoid possible "natural consequences"......portage.
River need not be in flood stage for hydraulics to form.

BOB

P.S. They can also "do a job" on a boat!

So,
what are you guys trying to say?..Just kidding. You’ve all reinforced everything I’ve ever heard. Thanks for the input.



Joe

Last summer
we paddled a river with a low head dam. Didn’t look too bad, but we decided to oprtage. Then played in the waves below the dam. Wow , 3 ft. or better waves to paddle in. Sure glad we didn’t try to shoot the dam.

Catch Basin

– Last Updated: Feb-21-05 4:35 PM EST –

A low head dam works much like a catch basin one may find at the end of a fast moving river leading into a harbor where there is a marina, boat traffic, moorings. When the water drops over the dam it drops into a troff which starts an eddie or a reverse flow. IN catch basins this traps large logs which could be a navigation problem, or damage a hull of a boat in a slip. The log stays traped in the troff until it is smashed into small bits; much like a human body would. I would rather run across the I-5 in California 10 times blind folded. One would have a better chance. Not to mention that there is a great many things all ready down there smashing around that would crush you long be for you ran out of air. STAY CLEAR-PADDLE SAFE-LIVE LONG

Drowning Machine
is the command term used within the fire and rescue communities. Avoid them at all costs.



BOATSAFE has a good presentation at www.boatsafe.com/nauticalknowhow/lowhead.htm



SYOW

Ran a spillway on a new dam once, and
only barely made it through the backwash. The guy behind me and his boat were in the backwash quite a while before they popped out. Low head dams are usually even worse.



Also, I have been known to walk an “easy” low head dam I knew I could slam through, just because others with me were not competent to do so, but might have tried anyway.

Afterthought …
Don’t know the title of the film, or where you could find a copy of it, but working on certification in Swiftwater Rescue, I saw a film of a rescue attempt, below a low head dam by some firemen/rescue personnel. The rescuers attempted to approach the victims, by going upstream to them in a power boat.

The boat was pulled into the hydraulic, the boat capsized, spilling several of the rescuers into the hydraulic. Don’t remember the final death toll, but seems like it was 2 or 3?

That one should be on your “must watch” list before you consider running low head dams.



BOB

One unfortunate day
I watched a public high school outdoor adventure program loose a student (barely rescued several others) to a canoe spill caused by a low overhead dam. There had been a crib dam in disrepair that you could safely run or paddle up to, in that same spot for decades. That year a person well connected to the governor was able to skirt many issues dealing with watersheds and replaced that dam with a lowhead dam, but did nothing to post or educate this popular fishing and whitewater run with any information about the new dangers that were now associated with the construction of a lowhead dam. The pool that fisherman had for years used and whitewater boaters launched from is immediatelty at it’s base. There were I believe two more deaths that have also occured at this same spot. And why was the old dam removed and the last continuous three miles of whitewater left in the state diverted to a tube? Taxbreak.