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Geoff Lawton @ PV1 - "Permaculture Earthworks"  RSS feed

 
Julia Winter
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Me again!

So, are you sad that you didn't get to go to the Permaculture Voices conference? Did you go but you can't remember what was said? Well, I am an obsessive note taker (most of the time) and I took notes at most of the talks I attended.

I will share them here with you!

Please note that this is in no way a transcription. These are my notes, taken in real time, on the fly, whilst trying to look at the slides and follow along. I find that note taking helps me synthesize information. None of this should be construed as an accurate quotation, even when I put it in quotes. (For example, I'm pretty sure not a single speaker used the utterance "Yo.") Much of the time, I am trying to summarize and it's entirely possible that I've gotten some things wrong.

My next notes document is geoff lawton. The topic this time was "Permaculture Earthworks"

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Geoff Lawton

Earthworks

I’ve worked with earth movers all over the world. It’s amazing to see the men turn on to what we’re doing. They often say “I’m going to do this at my place!” They are geosurgeons - they know what’s under the soil. If you want a really good operator, find a guy who races motorbikes, or stock cars. He’s got quick reflexes.

The guys love working with us, because we tell them to be creative, add a little shape in there. These guys are usually told to work as fast as possible (because they are pricey and paid by the hour). A good operator, he KNOWS level. He will see how it’s going to be before I do, which is really scary for me.

The machine in the video is a 27 ton machine. Every so often we might use a 40 ton machine. Bigger than that is rare. I’ve directed on 65 ton machine on one job. When you are working in the dry land you will have to go really big like that.

We can do so much in such a small time, to such a huge effect. Yes, it’s destructive but it can do so much.

I want to emphasize Robert Laturno’s work. (An American engineer.) (ed:I’m not sure why)

The way these machines have improved in just the time I’ve been directing them. (Cool story about the operator carefully scooping up turtles and “handing” them to Geoff with the excavator bucket.)

A good driver spends half his time going backwards. A bad driver spends most of his time going backwards.

Video of an A-frame level. This stuff is dead simple. Anyone can do it. Because surveying is a profession, once you’ve got the tripod and you’re looking through the device, suddenly people think it’s something they can’t do. You can. You don’t have to hire someone.

When you’re discussing a design with an operator, if you can convince him you know what you’re doing and you know what you want, they can go flat-out. They love for you to put in the pegs (if they trust you).

The operator is feeling the earth through the machine. Woman make terrific operators. You have to be sensitive. Young men are the worst. You can kill yourself by bringing too much material back and the bucket comes right back and hits the operator. (!)

We should be subsidized to be able to show how we can repair country. Instead, we are often prohibited from repairing country. I think it should be illegal NOT to repair country! I dream about Caterpillar calling me up and saying “We’d like to have you on our research and development team.”

A sensible government would give us a fleet of machines and let us train people in what they can do. We KNOW it’s possible.

One thing we’re very sensitive about in permaculture earthworks is topsoil. Here we are stripping off the topsoil before we do the earthworks. Not just dam sites - any excavation site. You can’t just bury good topsoil under subsoil.

We’re also super sensitive about erosion. We need to get water to behave more passively.

What I call dams, you would call an earth walled pond. These interact with the environment three ways. 1) they all leak a little bit - that water is recharging the groundwater. Swales do that really really well, but dams do to. When you’ve got a new compacted earth pond and you are filling it up for the first time, get in the water and put your head under and listen. You will hear a sucking sound, like a giant sucking through a straw. That’s water going into the earth 2) they all evaporate water, and that recharges the cloud base 3) they need to have a good spillway, carefully designed to prevent erosion. Once the pond is full, it’s a sheet of glass - perfectly level - and for every drop that goes in, a drop needs to spill over.

People worry that when you put in a dam, you are taking water from the cachement. You are not, you are increasing water infiltration. You are recharging the aquifer.

You’re not putting dams like this on a river, you’re putting them in places like up on a hill, along a ridge.

Video: here we are digging a test hole, and the material is wrong. (it looks gravelly) I’ve never put in a plastic liner. I have used a new material, it’s a geofabric with bentonite. It’s tricky stuff, but if it works, it makes a clearwater pond. Sometimes we will deliver clay to a site. That’s expensive, but some of our clients want that.

Video of sprouting plants - you need to move quickly to revegetate. Put a thin skin of mulch down and overseed with a nitrogen fixing cover crop. You can move right away with tree planting. The cover crop is a bandage.

Swales are tree growing systems, I just have to say that over and over. They function better as the trees mature.

Here’s a property where we created a wind tunnel with trees in swales, going over two of the ponds. We’re setting up where we want the windmill. We use the windmill to pump water up to the top of the hill, it irrigates the whole thing.

Here’s a bentonite lined pond, here’s a clay lined pond going in. The dump truck is delivering clay—it’s really dry right now

Here’s a spillway. It’s amazing how precise you can be with this. You need a long level sill. Level pacifies water. So important: level pacifies water.

Water is so important. My first sentence was about water. sepp holzer has said the same sort of thing. Water is so important.

Go on up at right angle to contour until you get to the top of the hill or the top of the ridge. There has to be one or the other at the top. You just go up at right angles to contour on Google Map

permaculturepower.wordpress.com is a resource for you

Now, just go on the internet and find the maximum 24 hr event - how much rain could fall in one day? Multiply the area by the rainfall of the maximum event, and you’ll get the volume of water that’s got to pass through your pond in 24 hrs. Divide by 24 to get hourly, by 60 to get minute, by 60 again to get second. You won’t believe how much is going over and passing through your spillway. You’ll see how little of all that water you are catching and keeping. Most of it will just go on through as it always has. You’re not making the Hoover Dam here.

When you’ve got the calculation worked out, you can visualize what the spillway needs to look like. You should never be causing erosion, with the proper spillway.

We can connect our ponds together, around landscapes. We can increase cachement and soakage at the same time. We can contain water up on ridges, where it spreads out and rehydrates more land.

As you start to develop properties like this, you’ll see what develops. When you can store water with things like this, you will get a dendritic pattern in reverse. At the top of every valley there is a key point (in a humid landscape). There’s only one top, right? Your pond goes up there, as high as possible. The choices are limited by geography. It’s common for key points to line up with key points nearby. That’s not a mistake - landscapes are shaped by water.

As you come down, your choices increase. As you spread out with the water features, you will start rehydrating the land. It typically takes about 7 years to really rehydrate the land. I think the 7 year/15 year cycle has something to do with sun cycles. You should talk to the old people who’ve been on your land/area for a long time about floods and droughts, about freezes and hot spells.

When you come down (from the ridge) and you start to add these elements together, you start to have more and more choices. I believe in the future we can have lovely things made of stone, with little gates. . . . right now I use plastic pipe. I can put a pipe through the dam. I can attach a loose elbow at the bottom, it can rotate to vary the level of the water. (He also describes one of Bill’s things that uses the elbow to direct water either this way, or that way. The ends of these water paths were 1/2 mile apart, all from this decision point with the elbow.)

When there were terrible floods in our area, Brisbane was under water, we had no troubles. All our swales were full at that point, but we were fine. The swales were operating as flood control at that point.

Water is the destroyer of systems. Water is the creator of systems.

You can’t make water go uphill for free. OK, a little via capillary action. Trees do it! We don’t really know how they do it.

The higher up water is, the more energy it’s got. The lower it is, the more life it’s got. (ed: ? I think he means nutrients) Water picks up everything - nutrients, toxins, all of it.

When you dump manure into a swale, and then it floods, those nutrients will go all over, you don’t have to do it. The water moves that for you.

Swales can fail, but it’s no big deal. You have to work to make your pond secure, but it’s easy to repair a swale.

Video: here’s a pig’s ear we’ve made into a silk purse. All the topsoil was at the bottom (from erosion) We terraced the hillside, but just did cuts, to use the clay for lining our pond. Then, we took all that topsoil and covered those terraces with it. We had a mound at the edges, to hold water on those terraces. Here it is, just 6 months later. It ended up being the most productive corner of the whole property!

Bill said: the more difficult they make it, the better your design. The more restrictive the landscape, the better your design. Geoff sees it now: when he is most restricted, he does his most creative work.

OK, after water comes access. It’s not hard to fit in. Access should run on contour. The hard surfaces will collect water for you. You’ll have a V-drain on the upside and pipes letting that water across to the downside. If you are coming down the hill, do that on the ridge. You’ll hit the swales at a 90 degree angle - no problem, just put in a crossing pipe. You can also use the swales themselves as access tracks (ed: wait, aren’t there trees in there??) Access roads should either be on contour or directly across it. Our cattle lane ways are on contour, above swales. The manure is mostly collected, but any excess will wash into the swales. Nice.

Q: you were saying that stuff in the test hole was no good for a pond. What was that?
A: it’s from a volcanic eruption. It’s clay that was fired by the volcano. It’s like terra-cotta. Once it’s been fired, it won’t absorb water anymore. Typically what we do, we have a back-hoe come in and dig 3 meters down. We pile up the material, switching piles as the material changes. In that case, we had an excavator on site so we used that.

You can use animals to help seal a pond, but most of my wealthy clients want it done now. In that case, we hauled in clay to seal the pond.

Q: what if I can’t find an excavator with a wrist?
A: you’ll get a sawtooth effect. You can use different equipment. Hmm, I’ve never had trouble finding an excavator with a tilt bucket. It really does make a difference. You’ve got satellite guided GPS machines. The Olympics in London was all done via GPS guided machines.

Q: you said you could hear the sucking when you fill a pond. Could you use that to find a leak?
A: maybe, I don’t know.

Q:
A: In arid landscapes, we are fighting evaporation, so we’re making just small bodies of water that we can shade. We are using lots of gabions, swales, etc. We are typically stuck drawing ground water, but that’s no problem as long as we’re not drawing from too deep.

Q: permission versus forgiveness. How’s it been for you?
A: playing our favorites in the order of size. A lot of what we’re putting in is erosion control. They’re not agricultural sized dams. What we’re doing is erosion control. Your pond is going to fill up with soil—there’s life in there, creating soil. You’ll have to clean them out on a regular schedule. So, you can call these erosion control.

The problem is usually because your neighbor downstream is worried that you’re taking his water. What they don’t understand is that your property will continually leak water down to him, even during a drought. One reason I liked the Zaytuna farm location is that there’s a little river at the bottom. The neighbors are on the other side

So, if you get the complaint, just empty the pond. Say, it’s not a pond, it’s a big pipe crossing.

Q: I’m a northern dude, what do you think of Sepp’s work? when do you think it’s good to go high and off contour?
A: I think Sepp is wonderful! I think everybody is wonderful, all the people here. It’s all different coat hangers in the permaculture wardrobe. Sepp’s stuff works really well in the mountains, in the cold climate. People talk about hugelbeds, and it’s not such a great idea in the tropics, because the breakdown happens during the growing season.

Isn’t a banana circle a hugel bed upside down and opened up?

Q: I talked to a holistic management guy who said that the animals will do the earthworks for you. What do you think?
A: well again, yes and no. Yes, the animals will do it. You can mix and match it all up. You can put it into scale. Sure, you can do it just with animals. That doesn’t stop you integrating trees into it, and that doesn’t stop animals eating the trees. If your fence is on contour, the animals will walk that line. Ecosystems are extremely diverse, and the interactive diversity gives you stability.
 
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