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Swales: The Permaculture Element That Really “Holds Water”

by Rob Avis

Michelle, Rowen and I were driving home from a vacation in the mountains when we passed by a swale on a farmer’s field in the middle of Alberta cattle country. Naturally, it piqued my curiosity and I had to stop the car to investigate. It was such a great example of how this simple technique can catch and store water on a large scale, we decided to make a short video about it….

25 Comments

  1. I LOVE swales…the only thing about our property is that we live in Tasmania and our entire 4 acre property is covered in rocks. We live on a very steep slope and could really benefit from the use of swales to slow the decent of water down to the river and out to sea but have no idea of how to circumvent the rock problem. Love the post however :)

  2. Swale are great but on my 1:3 slope it is not the good otion, too bad.

    @narf7 : try planting pioner species on contour (like sea buckthon), it helps infiltration (some numbers here)

  3. @ narf7, are they the kind of rocks you can use or just really big “look-at-me, I’m stunning!” landscape rocks?

    We have between 3 and 8 inches of sandy loam (or straight sand, depending where you dig) then another 8 inches of river pebbles, then clay, so I can kind of sympathise. I’m sure if I was keen enough I could pave my garden paths with pebbles – I have started filling in the holes in the driveway.

    Maybe there are some spaces between the rocks? Under the rocks? If you can move them – I’ve always adored the views around Tilba in NSW, with the big (house sized in some cases) pieces of rock visible in the hills, but actually doing anything with it would be a challenge.

  4. Small rocks that can be piled on contour will form stone walled earth backed swales and there are examples that are 1000’s of years old in the Middle East. If you back fill with soil and mulch you will speed up the process of growing trees on contour rapidly. Large rocks that cannot be moved are 100% run off and effectively roofs and can be swaled around to great effect for rapid tree growth because of the major increase volume of rainfall infiltration. Steep slopes can be net and pan earth worked with small catch pan basin mini earth worked for trees connected by diversion drains as net to trap and infiltrate water to each tree planted for steep slope recovery and stability. Swales work perfectly fine in all mixtures of soil media sands, sandy loam, pebbles, clay even volcanic ash has now proven to be fine, the pioneer plant and tree growth successional planting changes thats all.

  5. If anyone wants to talk about swales in clay that hold water for three months please head over to Mudlark Permaculture on the Permaculture global site and feel free to contact me. I have fine powder silt over quartz gravel over clay. Thanks for putting this up Rob, I can’t believe that Alberta countryside is so devoid of trees.

  6. I’ve been sitting in the sun on my tank the last few mornings, looking at the slope around it and trying to work out where and how you’d put swales.

    I haven’t come across the net and pan idea before and it helps – the whole block slopes gradually south to the creek but below the tank it drops more sharply from the east and west as well. I think that comes from the earthworks when the tank went in, but we bought as is so I’m just guessing.

    I couldn’t see how a single swale would work but linking catch pans makes lots of sense.

    Now I just need to read some more and wait for the frost so I can see where it flows too.

  7. narf7, your property sounds a lot like Sepp Holzer’s. Like Geoff said large rocks are great hard surfaces for capturing runoff but Sepp Holzer also uses them as thermal mass to store heat. That way you can create warm microclimates and grow cold sensitive plants that might not normally grow in Tasmania.

    I recommend you have a look at some of the Sepp Holzer videos on youtube. They’re really good.

  8. Carolyn, since you’re in Victoria, Australia, and you have swales in clay that hold water for three months, have you considered growing any water loving aquatic marginal edibles? You could grow taro really well with that much water, I’m in Melbourne and can grow taro in my regular garden beds.

  9. My favorite article yet and the comments are great. I have only installed one small 9m long swale on the front of my urban property and the results are amazing.. In fact, I killed two trees by not trusting that it was working and the drowned. Feedback – the swale works. It is the first step of any of my designs now…. Thanks Rob!

  10. These seem awesome. Does anyone use them in regular suburban blocks? Would they be a water hazard for young children? Or do they only remain full briefly after rain?

    1. i got many thing from this page but i want to learn about concrete Swale. if you can tell me please reply me

  11. Hi, great info!! Now, what are the particulars about having the swales in the pasture with the cattle? How can that be made to work?

  12. Can anyone reply to Lisa’s post I really would like to install a swale in my suburban block too. How deep and wide would they need to be? Are the bottom of the swales roughed after construction to improve infiltration and are they heavily mulched?

  13. Yes Lisa, you can make use of PC principles in designs anywhere. Just make the best of what recourses you have.
    We just cut swales on my property & have been impressed with amount of water they capture! Lots more to do of course. Ck out book by Toby Hemenway called Gaia’s Garden.

  14. Posted comment re: Lisa. About size & spacing depends on your site specifics. But in general swales can be 1-3 ft wide and usually 1/3rd of width for depth. (If 3ft wide by 1 ft deep) Although they can be smaller or way bigger – it just depends. About mulching – of course in some cases filling the swale full of wood mulch creates a big sponge that slowly releases water for your plantings.

  15. Spokane area-17″ rainfall/year. My 10 acres in pine forest with 6-8″ forest duff. What are your thoughts on building swales to charge small ponds in a forest setting where the water does not “flow” donwhill but is absorbed by forest duff. Thansks

  16. what if u have an obvious downward slope in a small garden plot? is it really necessary to build an A-frame & do all the intense measuring that I’ve noticed on YouTube? Isn’t that for much larger pieces of acreage? My husband doesn’t want to learn anything about permaculture.

  17. Does anyone know about using swales to help desalinate your bore water? Are these swales built on contour too? Does this create more of a problem then with the salt sitting in your topsoil or can salt loving plants soak it up?

  18. Hi, am in the process of setting up a tilapia farm in Trinidad and Tobago, I am gathering info and advice, thank you

    1. You fill the swale with organic matter or pebbles, something porous so that the water can soak in, but not pool and allow mozzies to breed.

    2. Mosquitoes are not an issue. The shortest duration of an aquatic cycle for any mosquito is five days. Swales very rarely hold water, above the surface, for more than a few days and mosquitoes need water for 8-14 days to complete the aquatic stage.

  19. Like Carmen, I am also interested in how we insert swales into a steep hillside with cattle grazing? Is this a ‘fence-off’ scenario? Or can a newly-built swale certain amount of curiosity/heavy hoof print (Dexters so a bit lighter)? Dead keen to hear in this, our driest year in the region for many years. Many thanks.

  20. Hallo ! Like Jackie Clark and Carmen asked. Can you insert swales into a cattle grazing camp or not..? I’m from South Africa and the drought is a serious problem. So any method to help store a bit of the rainwater helps.

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