AquacultureDamsFishLandPlant Systems

Building an Edible Floating Island

Here we are! We are underway with our Ten Week Internship with Geoff Lawton at the Permaculture Research Institute, Zaytuna Farm, in The Channon, New South Wales, Australia. We are a small group of only six interns, two teacher assistants and Mr. Geoff Lawton. The team has really formed a synergy and we feel great with some of the projects we have been able to complete.

The first project was in our first week of the internship and we built a floating edible island. Artificial floating islands and floating gardens have been used for ages — most famously would be the floating islands of the Uros on Lake Titicaca. Then you have the floating gardens of Mexico City which are in fact chinampas and do not float. However there was a time the “floating gardens” were actually “floating” due to Lake Texcoco flooding the valley of Mexico City in June 1629. The city was flooded by three feet and remained flooded for five years. The fields were underwater, so necessity pushed the people of the city to rely upon floating gardens to simply avoid famine.

Our edible floating island is probably much different than the floating gardens of Mexico City during the last great flood. The design of our modern edible island is simple and effective. It’s a small raft held up with an inner pvc pipe frame and is reinforced with bamboo. A plastic net and shade house cloth are ziptied to the frame to make a bottom. We then filled it with semiaquatic, edible plants. These include Aethionema cordiolum (Lebanese Watercress), which looks like rounded celery leaves and tastes just like it. It is used as a flavor additive to salads, soups or stir frys. Also Ipomoea aquatica, otherwise known as Kang Kong or Chinese Water Spinach, widely eaten as a stir fry vegetable and is the fastest growing leaf crop in the world. A relative of sweet potato, it is much healthier for you than lettuce in way of nutrient value. You can find it in supermarkets and it is used throughout Southeast Asia in many dishes.

Both plants were grown in pots and then transplanted with the soil to the net. There were concerns about keeping them from frosting over the winter if they remained in pots on the dams edge. So the floating edible island build is a floating experiment with the hope that the thermal mass of the dam will keep them from frosting.

Other than being an edible island, it is also intended as an additional underwater edge for life to live. We imagine fish feeding under its canopy and it being a hotspot for frogs and turtles. Hopefully when the roots have really developed it will also be a means for additional water filtration, aeration and increase the waters clarity.

Finally we launched the island and anchored it to the bottom of Paradise Dam. It sits as a splendid view from the dining area and I have enjoyed seeing the Kang Kong’s white morning glory flowers bloom and increase. I look forward to the first harvest and some stir fry!


  1. Hi guys, really pleased to see this experiment. I fell in love with chinampas when I did my PDC and have been looking at the two small dams we have recently built and thinking about the possibility of growing floating gardens, so I am inspired to give it a go now :)

  2. Erik I find your enthusiasm contagious and have signed up to do the upcoming internship. Just 1 question my friend-which of the following-cable ties, plastic net, shade cloth, and pvc piping- are either environmentally friendly,(or as a cornerstone foundation of permaculture)sustainably produced? Whilst the idea is brilliant, surely some other materials can/may be sourced/used, as I doubt the aforementioned were available to the Uros or the Mexicans. :-)

  3. Nice guys great idea¡ , chinampas rules!
    Try to build a bigger one just grab alot of empty plastic bottles, tide them together to a wood raft (kind of a raised bed in a wood frame soported by plastic bottles) there is a guy on the internet called richi sowa, look for him on facebook. This guy made an entire floating island (60 sqm aprox) where he lives actually in a lagoon in Cancun and has its own vegetable garden on that same island…. Just with bottles. And in case you want to do a chinampa maybe i can be helpful i have 3 on my back lot and i got to tell you… This system works incredibly well.

    Rodrigo Lañado

  4. Amazing Job!!! Brings more life to Paradise Dam! In some weeks, I hope to see a photo of the top view.
    All the Best For Zaytuna Farm
    Saudades Ivan Miguel from Portugal

  5. Historically people used bottle gourds ( lagenaria) as floats for rafts and fishing nets. They wont last as long as a plastic bottle though!

  6. Thanks Eric T-yet another use for the ever reliable multi purpose gourd. In relation to longevity though, do we compromise our core permaculture value of sustainability for the sake of an extended life cycle?? If so, where do we draw the line?? My thoughts are that we should not, as this only serves to “muddy the waters” when we attempt to convert the naysayers to the only option available for a sustainable lifecycle on this planet. :-)

  7. You can build a swale with a 25 ton excavator or 1000 people with shovels. Both will do the same job of re-hydrating, re-patterning and re-habilitating the landscape. Now you go out and try and organize, motivate and compensate 1000 people and while you are doing that i’ll be looking at my completed swale ready to plant my food forest that will provide nutrition for the land and its people for the next 7 generations.

  8. Plastic bottles are in surplus EVERYWHERE on the planet, and lengths of secondhand PVC pipe can be picked up cheaply at house demolishers and tip shops. We are up to our necks in surplus and garbage, lets re-purpose it.
    Nice one Erik.

  9. Sorry Eric-how many man hours and at what cost to our planet did the manufacture of that excavator cost-not to mention the environmental damage done in lubricating and fuelling it, or mining the steel for it. And if motivating your suggested 1000 people is really that hard, well then you need not worry about feeding the next 7 generations as there will likely be nowhere for them to live. Don’t get me wrong-I am all for progress and making life as easy for ourselves as possible, but not at the expense of our planet. As Bill Mollison himself pointed out in the taped Designers Course presented with Geoff Lawton at Melbourne University-it is amazing what several thousand starving Indian women can achieve. Necessity is not only the mother of invention, but a huge motivator. This is not an attack Eric, merely my opinion that the core philosophies need to be upheld in order to convince people of the merits of permaculture. There is indeed a fine balance that needs to be achieved in order to convince people that changing their ways is not only for the best for ourselves, our planet, and our future generations, but also practical-and that they may still maintain a quality of lifestyle that is not only the equal of that to which they have become accustomed, but better. I am not suggesting that we do not utilise that which is available to us-merely that we note that these practices are not sustainable and that we seek alternative methods that are. :-)

  10. Hi Peter please please tell me how you grew the computer tree you are using, or please excuse my ignorance if it is a domestic animal computer breed you have been able to speciate and select? Also how have you organically and biologically tapped into the internet, do you have a special fungi connection because I would really really like to know this TOO?

    Please do not keep that all a secret ;), please please let us know ;).

    To quote Bill Mollison the relevance here is the ” the pollution of manufacture of an element is in relation to the potential life time of the product” this is all relevant to the point in history where we are at NOW.

    We need to realise that we are all trying to move with good intention from our present comfort zone (position of privilege) towards a position of absolute abundance. The big concern for most of us is can we set out and lay down the relevant examples in time to create a positive tipping in time before a catastrophic irreversible global environmental event takes place causing great suffering to billions of innocent people.

    We can make a floating garden with just bamboo, using one of our large bamboo’s (, etc) as the main flotation and we can tie it together by splitting the weavers bamboo (textiles gresillus) or we could use native lawyer vine which is a climbing cane.

    We repurposed what we had available just to be appropriate to the present time to show what is possible and to give you the chance to improve it.

    Thanks for giving me the opportunity to help.


  11. Peter, if Erik doesn’t mind I might have a bit of a wander down the machinery vs manpower tangent with you.
    I think Bill got all those women to do those earthworks in India because “Woman Power” was in surplus. Bill empowered them and gave them a future in the context of where they were and what they had.

    I have watched the same DVD of Bill and Geoffs course, and its only one lesson from Bill, I have heard him speak about earthworks in many variations. Bill also has a story of his neighbors at one stage telling him that they presume he has given up all that ‘permaculture stuff’ because he had a bulldozer at his place doing earthworks. While Bill certainly can show people how to dig a dam by hand I can bet he has never dug one by hand on his own properties, and I bet he has put in many dams and water harvesting features in his lifetime. How many dams, ponds, chinampa canals, swales etc, did Tagari farm have? You use what you have.
    Also, I have done Geoffs earthworks course and I learned that we are at an interesting juncture in history. At this moment in time we get to leverage fossil fuel resources to restore and re-pattern damaged and degraded landscapes.
    And if you think about that a bit its just about appropriate use, as man has used massive fossil fuel resources to damage and degrade our planet, we have destroyed water courses, caused erosion and damaged natural hydrology everywhere, using machinery now to undo some of that damage is perfectly acceptable by my thinking.
    Peter, have you put in earthworks by hand? Have you done any earthworks at all?
    Peter, you mention ‘core philosophies need to be upheld in order to convince people of the merits of permaculture’. If you have ever seen good earthworks done, and the systems they support, the merits of the work speak for themselves, which is where I think Eric is heading with his comment. Also, the Permaculture Designers Manual has quite a few pages on machinery for earthworks, no where does it say that machinery is against ‘core philosophies’. Machinery is just a tool to be applied to Design, in the context of where you are and whats available and what needs doing etc.
    Hope that helps.

  12. Hi Geoff
    The cynicism at the beginning of your comment is disappointing, and for all intents appears to be a personal attack on someone voicing their opinion-but I am certain it has provided many with a chuckle. I am happy to stand corrected if indeed any of the comments I posted here contained either cynicism, or were attacking of the person posting them, including the original contributing author. Please(and I wont use the emotive second please)can you explain(just to me, I don’t feel the necessity to employ the group mentality) how such comments can be deemed to be “care of people”-or am I lacking in my understanding of that ethic also??

    Further, as I am currently booked to do your upcoming Designers Course and subsequent Internship, I am interested to know if this is how students are responded to if at any time they raise questions or voice their opinion whilst in attendance?

    The second half of your comment was indeed helpful-so thank you for that.

    I will leave this message here by drawing your attention to the final sentence of my last post, and also the fact that at no point did/have I suggested having ALL the answers anymore than you yourself or anyone else, although I am looking forward to gaining many more during my stay at your Institution. :-)

  13. Peter I am very sorry for offending you, I do apologise, but sometimes a utopian shock wave does sound quite funny. We like to say if your not having fun then you must have got the design wrong and we have a lot of fun here at Zaytuna Farm. Another saying we have here is the beginning of almost every answer to a permaculture question begins with “it depends”. We also work in a very real situation relative to this point in history as an education centre that is also a demonstration site using materials that are available to us. We explain the appropriate use of materials in their relative time of use and purpose to achieve the results needed.
    Zaytuns Farm is a reality shock for many PDC students and interns, we (our teaching team) help everyone who comes here with an open mind and a genuine intention to learn, to move as quickly and sensitively as they can into a permaculture reality for themselves.

  14. Hey Peter, have fun with Geoff and enjoy the learning experience, by the end of it you will know all about appropriate application of resources, amongst other things.
    Enjoy the learning curve, a PDC is a transformational event, if you are not transformed by end then the teacher got the design wrong!
    As for Geoffs joke, perhaps you haven’t been following some of the other comment threads, he has been copping a bit of “stick” lately, so perhaps let that one slide.
    I hope my comment from earlier today helped in some way.
    Yours Abundantly
    Carolyn Payne-Gemmell
    Mudlark Permaculture

  15. Hi Peter

    I think everyone has said it well already, but I want to throw in a little more.

    I’ve said before, and will say again, imagine if all the people currently living today and using fossil fuels for frivolous uses were instead using them to transition the world into a post-carbon age? Instead of truck racing and flights to the Bahamas, we’d be using the fuel to repair watersheds and revitalise landscapes everywhere.

    It’s important to understand that while nature can regenerate, we humans, when endowed with eco-literacy and experience, are able to speed up that regeneration manifold.

    Indeed, in some parts of the world, even if you left nature alone for generations, it would not be able to repair itself without human ‘interference’ to speed regeneration along.

    I don’t think anyone disagrees with your base points Peter, but I think the key thing is to realise context. In Australia, where Zaytuna Farm is situated, hiring 1000 people to help dig a dam and swale system is beyond cost prohibitive. The minimum wage in Australia at the moment, I believe, is AU$16 p/hour. Multiply that by a 1000, and then multiply that by however many hours it would take for those 1000 people to get the job done…. In other words, the work would not get done… Or, if it did get done, then imagine the tuition fees Zaytuna Farm would have to charge students to come and learn! Imagine taking a PDC for $50,000 p/person, or more!

    Getting 1000 pampered Australians to do the work for free is beyond difficult – unlike the ‘born of necessity’ situation you mentioned in India.

    Yes, when we use an excavator, we are not paying the full ‘inventory’ of real costs that this machine represents, going all the way back to where the metal is mined, etc. etc. etc. If we were to incorporate all those costs, we wouldn’t use the excavator, but still the job would not get done….

    The only way the ‘puritan’ method can financially be viable, is if the rest of society simultaneously started to incorporate the real costs of machinery into all of their actions/activities, and thus started to move away from using it, due to its recognised ‘expense’. If that happened, then the economy would change dramatically, becoming more like it was 200 years ago.

    In other words, a truly ‘puritan’ approach to everything we are doing can only work if our present economy is turned upside down – if it starts to deal in reality, and not continue to live in a dream of limitless energy as it does today. This can only work if most people are involved.

    While we wait for (and work towards) ‘reality’ to sink into civilisation, we must work within the economic situation we now find ourselves in. And, as Geoff expressed, the key thing is to showcase solutions as far and wide as possible, to help shape the transition along positive paths.

    On this site I’ve often shared thoughts and concepts about the economy, and how it needs to be turned upside down. Sometimes people have responded in frustration that I even mention the subject – wanting me to stick to topics of cabbages and composting loos. But unless we address how the economy functions, we will continue to struggle to live the way we know we should/could live.

  16. Peter, and others, please read and think about what I shared in this article:

    Much of Sri Lanka today is a lush green semi-paradise. If it wasn’t for human intervention, however, it would today be largely arid and barren. It was transformed via large scale earthworks, done progressively over centuries. How was it financed? It wasn’t. It was mostly done by slave labour.

    Today our machines, powered by fossil fuels, are the slaves.

    Neither situation is ideal. The ‘ideal’ will never be reached until humanity has put an appropriate value on eco-system services, and shaped our economy around that.

  17. Hi Craig , Carolyn and Geoff
    Thank you all for your comments, and yes Carolyn your comments were helpful and appreciated-sorry I didn’t have the opportunity to reply sooner.
    Thanks also Craig, and yes whilst I am a “puritan” at heart, the head is a realist and I agree with what you have written.
    And Geoff, thanks for the reply. I look forward to meeting you and learning as much as I can from yourself and all the team whilst I am there.
    Kindest regards. :-)

  18. Peter – I am so envious that you get to take a class at Zaytuna Farm with all the good folks there!! Enjoy the heck out of it and I hope you write up your experiences and share them on this website. As for me, I will just have to live vicariously through these posts for now.

  19. I wouldnt bet too much money that Bill hasnt built earthworks by hand! His mentor PA Yoeman reccomended that you may need to get out with a shovel to protect your investment!
    In many sites massive earthworks may not be nessisary ie trees planted on contour may suffice

    How does one get to be a PRI ???

  20. Andrew, Bill put in something like 47 dams and six kms of swales at Tagari farm, like I said above, I don’t think he dug any of the dams by hand, but someone who knows can prove me wrong.
    I think Geoff is up to 13 plus dams at Zaytuna, I am fairly sure they were all dug by machine.
    I have a dam and a dam/wetland complex and 2 kms of swales, level sill spillways, assorted silt traps, all manner of experimental water soakage features, and plenty more in the pipeline, all dug by machine.
    How much earthworks a person does, by machine or hand is all in context, I am re-patterning my land to show people everything I can about what is possible, its a demonstration site.
    I am doing what interests me and applying the resources I have available.
    The way I see it, where I am in Australia, a quick scan of google earth shows me that all the natural wetlands around me have been drained and destroyed, and a talk with the local earthmovers just highlights the destruction as all their work is about drainage.
    After a two hour walk of my property with the earth moving man discussing my plans, he had an ‘ah-ha’ moment, he said “oh, you want to hold the water, I am always doing drainage”
    I wasn’t suggesting Bill has never wielded a shovel, I just couldn’t imagine he dug 47 dams with 1000s of Indian ladies and little wicker baskets.
    I don’t want to railroad Eriks article on the earthworks vs no earthworks tangent, its all in context, it all depends- where you are, what you have, what interests you- horses for courses.
    [ How does one get to be a PRI?] Do you mean a PRI Master plan demonstration site, click up the top right hand corner on The Permaculture Master Plan and follow the trail of information Craig had laid out.

  21. To the contributing Erik
    I just wish to apologise to you my friend if my initial(or any subsequent comments) caused any offence. None was intended, but I can understand that my phrasing of what I was trying to express could have been better, and may have been misinterpreted. I hope your experience continues to be as educational and enjoyable for you, and your future abundant.
    Peter :-)

  22. Greetings, and thank you for this excellent site.

    The idea of a floating island is wonderful!

    However, I would like to raise one point which has not been mentioned so far in relation to the PVC piping and other plastic bits used in its construction. Beyond the issue of the sustainability of PVC use/recycling, there is also the matter of its toxicity: PVC leaches phthalates into the environment. These are endocrine disrupters, which have harmful effects on human and animal health, particularly their reproductive function.

    “Phthalates at levels found in the environment can also affect reproduction and development in a wide range of insect, shellfish, and amphibian species. The consequences of disrupted larval development, decreased numbers of animals hatching from eggs, and delayed emergence from eggs are fewer live offspring and smaller populations in subsequent generations. Research also indicates that phthalates affect fish directly: exposure of rainbow trout (Oncorhynchus mykiss) to an environmentally realistic level of DBP affected their ability to grow normally. Similarly, DEP affected brain, muscle, and liver function, so exposure of fish to low levels in the aquatic environment could impact nerve function and conversion of food to energy. ” (

    More information is available on the wikipedia phthalates page.

    So, even though plastics may be a widely available, cheap resource, making that same island with bamboo or gourds sounds safer and more permacultural to me.

  23. I find it odd that so many people are trying to find mistake with this concept by complaining about plastic when the sentence “Hopefully when the roots have really developed it will also be a means for additional water filtration, aeration and increase the waters clarity” clearly shows lack of biological understanding. How will the roots provide aeration when they themselves will be drawing oxygen from the water?

    Regardless of how little the writer knows of biology, this floating food raft is a great idea. It has been tried in the past by numerous people and has worked well.

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