Leaking Dams


I have a question from Leszek, “My soil is a combination of loam “with small jagged pieces of rock “and below a depth of one to two meters “there are solid slabs of rock “which water flows out immediately. “After attempting to seal
the pond sites with clay, “bentonite and earthworks, “my patience has ended, “and I think I may need PVC, “EPDM or RPE liners “to have pool ponds at all. “With over 800 mil per year
of rain and a humid climate, “ponds should be easy, but
it appears they are not. “How does one use non-natural materials “for ponds in permaculture? “Is this all right? “Even natural ponds here
observed to dry and crack “after several weeks of drought, “appear to have lost
their seal and now leak, “even though the rain has returned. “Why would this be?” Well, it doesn’t appear you
have enough clay in the soil. You don’t have clay in the subsoil and you need half to one meter of clay, actually it’s nice to
have one meter of clay if you’re going to seal a dam
because clay in a dry time, if it all dries out, will crack down half a
meter, but not a full meter, and when it rains it all seals back up. And if you say those
natural ponds have dried out and they’re steal leaking now
rains returned after a drought and maybe ’cause they’ve
cracked right the way through and they will biologically seal over time. Nature’s not in any hurry. It’s got a longer time
scale than our lifetime. So, all of these things can
seal with biological sealant, and that’s organic matters,
glees, green materials, animal manures and all these other things. Now we’re always in a
hurry, we want things quick. How did unnatural liners, you’re asking, how does one use non-natural materials for ponds in permaculture? Well, it’s all a matter of permacultures relative to this point and time. Right now, we’re using
computers to take this course and they’re not natural computers. We’re using all kinds
of non-natural things. We are compensating by what we’re doing. We’re putting life-rich systems in. We’re putting massive amounts
of plant materials together, just a few willows, just a few bamboos, just a few of our novel
ecosystems compensate for some of those non-natural materials. The pond itself is an
incredibly life-rich system. Now I’ve decided to answer
this question right here next to a dam called Wood Duck Dam. I should be under water, but
I’m not because this dam leaks, and it’s leaked right down to the point where I think it is
leaking through the subsoil over the 100-year flood
line into the river. And this is the second dam
that’s leaked on our property, the first one I sealed with bentonite and I had to get a nice gradual
30 degree slope inside it, bowl it out, make sure there was no rocks, then spread the bentonite thickly so it was all white on the surface, then put a foot of top soil in and roll that soil down
on top of the bentonite and then introduce water and it sealed. That’s the way you do it. You’ve got to have a
nice bowled out shape, you’ve got to spread the
bentonite very thickly around, then you’ve got to put
a foot, 300 millimeters, of rock-free soil, subsoil or soil, on the top of the bentonite and roll it in and it should seal inside. Now, you’ve got solid rock slabs, that’s a little bit more difficult. I’ve got a problem here, that I’m next to the
100-year flood line here, this is the top of the 100-year flood, the river’s over that way, and I think it’s going
under the flood plain. I’ve tried to seal it a couple of times, I’ve reworked it, and I
think I’m going to put a bentonite impregnated geofabric down. Now, we’ve done this, we’ve
brought clay into dams, it’s quite expensive
trucking all the clay in, we’ve sealed with bentonite. There are polymers you
can put in the water when the dam’s full. This dam fills in the rainy
season right to the top and overflows and then gradually
goes down as it leaks out. But where clients have got us to put in the bentonite impregnated geofabric, you’ve got to get a nice bowly shape, you’ve got to lay it out and
put bentonite on the overlap, you’ve put a trench all
the way around the outside and fill that with gravel
all to tuck the geofabric in, but once the water hits it,
it swells up and forms a seal. And you lay a bit of
soil over the top, again, and pack that down. Now where we’ve done that,
they’ve come out really clean. They’ve come out really clear. Very beautiful. They don’t muddy up at all, they come out like a
natural swimming pool. So, I’m keen sometime in the near future, possibly this year if things work out, to rework the bowl in this dam, and this has got a big
tail back on it, this dam. Goes back into an old gully back in here, floods back like a big
fork-tailed tadpole. I’m going to rework this, look at putting a bentonite impregnated geofabric through this, and then rebuild a wall here where the camera man’s standing , I’ll turn around so you can see
where I’m standing, alright? I’ve got an electric fence here, I’m grazing the cows here at the moment, I’ve tried grazing the cows
through it to stop it leaking, I’ve tried having a
couple 100 ducks in here to stop it leaking, I can’t
seem to stop this leaking. It’s a beautiful dam, potentially. So I was going to rework that area there up into a wall so it’s one dam here and I was going to fill an area
here with gravel and big rock and make this a giant filtration system so that the water flows down the valley, goes through a rock filter
like a natural cleaning system, and then overflows into this dam here with bentonite impregnated geofabric, making it kind of halfway
between a dam and a pond and a natural feature and
a natural swimming pool. It might be a nice blend. But sometimes, these are the
sort of things you got to do. And you can do a lot with
earth-moving equipment. You’ve got rock, this is
going to make it difficult, so you’ve got to screen out the loose rock to put bentonite in. Where if you can clean
up with a geofabric, clean up and then line a geofabric in, you can get a really nice finish that looks like a very natural pool. And I think they look a lot better, and probably are permanent then because the geofabric holds the
bentonite, that seals, you get biological material
sitting on top of it and you don’t have a plastic that eventually breaks
down and needs replacing. That’s my advice, let us know what you do.

20 thoughts on “Leaking Dams

  1. Thanks mate this was a great video as I have a similar problem with the rock.

  2. С этими вопросами лучше обратиться к Зепу Хольцеру. У него большой опыт.

  3. Wow ☺☺👍👍👍 incredibol men thanks for video

  4. I often wondered if you could solve some of these leaky dams with a concrete vibrator. Get a layer of water in the pond, dissolve some manure or other gleeing agent in there, and then vibrate the mud so the fine particles will form a dense layer. It's just an electric hand-held device, but it's a lot of work for a big pond, as you'll need to keep raising the water and vibrate the edges of the pond ever higher. I remember someone on Paul Wheaton's permies.com showing a series of photos showing how they sealed a pond: https://permies.com/t/38201/Progress-Gleying-Pond-Pigs

  5. Hey! About harvestwater What do you think about organic polyter ?

  6. Just a thought… Why not develop a hemp textile, impregnated with tar, as was being done to close up the gaps in wooden ships for many many years? Hemp fibers were the only material capable of withstanding the harsh conditions out on the ocean. And when you create natural tar out of wood, you'll get charcoal as a by-product and fertilizer.

  7. Bentonite impregnated geofabric. I just learned about something new. I've made one pond in my life so far – about 1000 litres (if it filled all the way) hand dug – in my life so far. I'm planning on building about many more over the next 5 years or so along with a bunch of swales to slowly lower the water. We have tons of clay here and tons of rain. I had to dig through lots of gravel like consistency stuff, but got down to clay and then pounded clay (about a food wide) wall from under the clay I had reached up to the top on the down hill side of the hole – didn't particularly take advantage of the topology, but it was a flat place under my swale's overflow. It held very high for a week or two. It holds okay now but about a foot or more under where I was hoping for. I'm going to keep experimenting – I was considering a liner but I'll just try another and maybe look into this bentonite impregnated geofabric.

  8. Sounds like a good situation for an underwater compost to accelerate the biological sealing processes.

  9. if i dug out a whole dam with a pick and a shovel and then it leaked id be fucked lol

  10. I saw Geoff's video about the ducks when he tried sealing it that way. I adopted that program on Tarashire. It worked for us, sort of. The ducks have to be continuous. If we remove the ducks, the dam leaks. After watching this, I now wonder if gravity is our advesary. I think the walls of the pond are to steep. Just like the geocloth, I wonder if the duck glee settles instead of adhering to the soil like I thought it would. Hmmmm.
    Never has there been a Lawton video without impartation of knowledge/ideas. The single most valuable human on Earth at this moment. 😉

  11. GCL liners are not only probably liflong holding water, but they are also selfhealing if a punctuation sjould accure.

  12. Always the sign of a good consultant, willing to try new ideas on his or her own property and then advise clients on best practices. Well done.

  13. Hi Jeff, what do you think of Zach Weiss work in this area of water bodies, and is there much of a difference in the way you both think about water being moved and stored on the land? lv, your work big green hug!!

  14. Polymer Innovations have a dam sealing product that could help. https://www.polymerinnovations.com.au/earthen-dam-pond-sealers.html?gclid=Cj0KCQjwhJrqBRDZARIsALhp1WQJNKK3rMClpathf8xUgfUqdtNidIndpuutkosjaLYIUDhgUqZaCD0aAnLpEALw_wcB

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