Searching For A Floodgate That Really Works


fa floodgate that works…

From GENE LOGSDON

There is nothing so lovely as a pasture field with a creek running through it, but you will pay for it a thousand times over.  If you have a pasture, you have livestock grazing there, and so where the creek enters and exits the pasture, you must have fencing decidedly different from what you have on dry land to keep your animals from wading out of the pasture and to keep your neighbor’s animals from wading in. We’ve always called them floodgates. So far as I know, no one has yet invented one that really works without spending a fortune.  I was certain, when confronted with the necessity of floodgates, that I could design one that would work without my constant attention. A hundred or so floodgates later, I admitted defeat.

Here is the situation. The gate or fencing over the creek should be able to rise as the water rises and then settle back in place when the water recedes. If you just run fencing through the creek, like three strands of barbed wire, the flooding creek will make short work of it. That’s because water is not the only thing that flows down the flooding creek: also tree limbs, corn stalks, dead grass, flotsam of all kinds and all this mish-mash tends to pile up against your floodgates and eventually they give way.  So what you need, as farmers for centuries have realized, is a gate than rises with the water.  Seems simple. Just stretch a pole or cable across the creek  and hang a swinging gate on it. As the water rises, it pushes the gate out and upwards and as it recedes the gate floats back down in place. Never is there an opportunity for animals to get past it.

But soon, very soon, the floodgate designer is confronted with the Great Mystery of Moving Water. In order to hang the gate above the creek, there must be posts or anchors or something on each bank to hold the cable or rod from which the gate hangs. What happens is that during flood time, the moving water in the creek will gnaw away at the dirt around any obstacle in its path, like for instance a post, eating determinedly back into the bank, year by year moving out the dirt on the bank side of the posts that hold the floodgates. Eventually, sooner rather than later, the creek is twice as wide at that point than it was before floodgates. Even if you are lucky enough have two big trees positioned across the creek from each other to act as anchors, the water will eventually sweep away the dirt from around the roots and collapse the tree. Your posts will sag as the area of washed out bank behind them deepens and that area must be constantly blocked off with additional gating of some kind. But the more you block the water that way, the more stubbornly it will eat away at it. Doesn’t sound logical, I know, but believe me, you could put a cement wall back into the banks on either side of the creek five feet and the flooding waters would eventually eat away the dirt at the ends of it. I suppose if you went twenty feet back into the banks, you might win the battle but no one is going to put that kind of money into a measly little creek.

My father finally just bowed to reality and stretched several old board gates across the creek and up the bank on either side to connect with regular fencing, with flimsy steel fenceposts to hold the gates in place. Every year the gap got wider. Every year the wooden gates jammed full of flotsam, broke over and were partially swept away. Every year there was a spring day scheduled for repairing and replacing floodgates. According to tradition, a farmer was responsible for the floodgate where the creek entered his property, not where it exited. This often led to trouble when one neighbor did not have livestock and refused to do floodgate maintenance.

So finally it was my turn to tend to floodgates and after a youth of helping repair the things, and seeing animals find a way through them when they got dilapidated,  I was going to show the world how to do it right. I built a foot bridge across the creek, using old electric posts. I hung board gates from the bridge. I of course had to have posts on either bank set deep in the earth to keep the bridge intact. I was so proud of myself.

Year by year, high water got under the  bridge at either end and washed away the dirt little by little. I had to put in more posts to hold the bridge in place and add to the bridge. More posts meant more water gouging. But it did last about eight years so I shouldn’t feel too defeated.

What I finally ended up doing was to place light, easy to handle, cattle panels across the creek and up the bank on either side— the gap between the banks was by then twice as wide as it had been when I installed the first floodgate. I used skinny steel fence posts to hold the panels on either side of the waterway— less blockage of water. I set two panels, each 16 ft. long, in the creek and up the banks, fastened at one end to the posts on the banks, with  only a very flimsy piece of wire holding them together in a standing position in the middle of the stream. High water swept them open and back against the downstream bank and I had to be sure I was there when the water receded to dig them out of the mud and stand them back up in place again. Not fun.

It’s too late for me, as I have admitted defeat and retired from pasture farming with two cattle panel floodgates still buried in the creek mud. But if any of you have found a low cost floodgate that really works more or less on its own, let me know. It is time that creek-side farmers got a break from the almighty power of moving water.
~~

9 Comments

My experience with floodgates has taught me that they are very efficient facilitators of social interaction. At least once a year when we used to pasture the front corner of the farm that has a creek angling through it, we would get invitations from neighbors that we had never met to come get our cattle out of their yards. Not all of the invitations were extended with good will however. We did find a “floodgate ” solution eventually. We put up a permanent fence on the east side of the creek with plenty of buffer and let the creek and few acres on the other side go wild. The creek area doesn’t look like a city park as it did when we were grazing its banks but it’s probably better off environmentally and I do sleep better during heavy summer rains.

The creeks that run through our place are so wide, there’s no way we can have a flood gate. So we run barbed wire fencing out into the creek a little way. It seems to work much as James describes the barbs above. Occasionally stuff tangles in the wire and we have to replace it, but it keeps the critters home.

James is right, placing a boulder barb can help. It redirects the energy of the creek, it is useful around bends for moving the thalweg (the area in the creek that is ripply and turbulent) back towards the center of the creek. The thalweg scours out the soil the most. Here in WNY the boulder barbs are used in many creeks to prevent roads from being undermined.

You could also fashion a headwall out of precast concrete lane dividers like the use on the road. The headwall would look like the concrete they put out in front of bridges or culverts to contain the stream, cut back towards the bank 45 degrees to channel the water where you want it to go. Some time and expense into engineering effective flow control systems might be worth the effort. Ask the county highway department what they would do, someone could likely help design a good solution.

In dealing with good-sized rivers locally the engineers and hydrologists I’ve worked with in a past career often used what are called boulder barbs to reroute the force of the water away from what you are trying to protect such as in most cases a highway or bridge. Without going into the hydraulics involved in regard to why placing rip rap or other obstacles in the way of the water only to see them fail, a :”Barb” functions to redirect the energy of the stream back toward the center of the stream instead of trying to directly overpower the energy of the stream.

The barbs are built with a large boulder fence dug (keyed) into the bank to avoid having the water simply cut behind the structure, then the boulder fence is continued into the stream at a constantly decreasing elevation; meaning it is lower in elevation toward the center of the stream. The water encounters the boulders then redirects at roughly ninety degrees to the angle of attack. In simple terms the barb is envisioned as if you are facing the stream with your face downstream then move your body so your back is about 45 degrees upstream; your right hand will be pointing downstream toward the right bank and your left hand will be pointing upstream toward the center of the stream. Envision the boulder fence parallel to your body. It is a simple concept but hard to describe.

I think a resourceful homesteader could replicate such a structure from manageable sized boulders or even logs or even make a bundle of small logs constructed with the same concept to achieve the same purpose.

Famous hydraulic Engineer Don Reichmuth developed the art and science of installing these under the auspices of his company: ” Geomax” out of Spokane, WA. I don’t know if Don is still with us but I suspect a Google search will show examples of his work which illustrates the concept in pictures and graphics better than I can with words. I’m not saying this is the perfect solution to the floodgate dilemma but could be a tool to help improve the durability of a floodgate without widening the stream though flood erosion of the banks.

Gene, If a floodgate lasting 10 or more years in Southern IN where we get 2 – 4 floods per year is a model that works, then I have one. My grandfather stretched a steel cable tightly between two trees and suspended 1″ x 8-10″ oak planks down to the water level from it (~10-12′). He put them close together and put a 2×4″ or two on the down stream side to maintain alignment. It even worked when a couple of planks eventually came off.

Now that I’ve retired and returned to the farm, I go with “the flow” and just stretch 2 strands of barbed wire down the bank and across the creek held in place by 17 gauge wire at the ends and to steel posts (angled toward downstream). When it floods, the wire breaks loose and lays against the bank. Later I shake off the debris and reattach.

Also I read your excellent book “All Flesh is Grass”. In it you and Bob Evans lamented that that there was no breed designed for year-around pasturing so he used Charolais. I am well along in a cross breeding program to develop a grass-fed breed that is perfect for Midwest winter grazing. You have my email if you want to contact me. Steve D.

Thanks so much for this article! I just noticed my cattle panels half buried… again… and wondering why I’m such a dope that I can’t figure out how to fences across the little stream that runs thru my paddock.

Now I see this problem has vexed many minds greater than my own.

In farm show magazine someone got the ingenous idea of using those plastic barrels connected by a rope or wire of some nature. It rises and falls with the water level.I havnt tried it myself . My new place doesnt have a real crick to try it onIt makes me wonder about the fence wire and steel posted one at my old farm.Now if i could just walk good enough to reach it. lol Hate to see you retiring from pasture farming.Still try combing my old farm journals and organic gardening and farmings to read and reread old Gene Logsdon stories. My favorite was the new farm with ear corn harvest and one on corn pickers in the same issue.

Sorry Gene, I have not admitted defeat but accepted the same solution of Cattle panels and T-post. Here in Iowa it is almost a 4-5 times a year to stand them back up. But I still find this easier and less expensive than rocking the banks. Fast moving water and floating tree debris just washes the rock away in heavy rains. Since I live in the middle of big ag (East Central Iowa), there are no neighbors to maintain the entry of the creek to my property, so I must maintain it. Its really too bad as this creek is naturally spring fed and some of the clearest water I have seen in my county.

You’d have to figure out what power source works for you. Either a solar charger, battery, or 110v. But couldn’t you string across the creek, a single strand of electric fence at normal fence height, then cut many pieces of light duty chain to hang from the wire? The chain would be cut longest for the middle of the creek and shorter near the banks.

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