It’s 2am. I’m sitting on a nice toilet in a nice hotel room in a nice little town in Africa. But I don’t feel very nice. Three weeks ago I arrived in the town of Musoma on the eastern shore of lake Victoria, Tanzania. It’s my second time here. It’s unusual to return to an old permaculture posting so it felt both strange and comforting to visit old friends. They had assumed I would return again as to them I was family and family never leaves for long. But I am mzungu, white man. And in the West, we never stay for long. But I had not been sick then.

I contracted diarrhea two days after arriving. Not crippling, but enough to make my trips to town short, consciously timed ones. Not bad enough to panic. Perhaps that is why three weeks later I’m sitting on the toilet once again at 2am in the morning. Only this time it’s a little more serious. I contracted malaria two days ago and had moved from the delirious, early stage effects of high fever to feeling just plain horrible. On top of that, I had unknowingly overdosed on a western folk remedy and have been violently vomiting for the past eight hours. My one small cause for relief was a by product of my tiny bathroom. I could release my bowels and vomit into the hand basin at exactly the same time. This I had adeptly managed several times this past evening although I over shot the bowl the first time. Must remember to tip the cleaning lady extra in the morning.

I was not unaccustomed to this kind of experience in my three years in Africa. Although I dare say my friends would not be envying my present situation; this particular African flavour….

GRA is a small non profit NGO based in California, USA. In their own words, they are “committed to building a better world – one based on ‘respect for nature, universal human rights, economic justice and a culture of peace’ as expressed in the words of the Earth Charter.” Yes, all NGOs sing a similar song, but I happen to know they are very serious about it. I’ve worked for them before.

About three years ago Geoff Lawton, one of the most respected leaders in the field, conducted a two-week PDC (Permaculture Design Certificate course) in a small fishing village at the mouth of the Mara river. Based on the success of this course, GRA decided to develop a full demonstration garden on a plot in the centre of the village. Geoff contacted me. I contacted GRA. I soon arrived for a three month posting to teach six separate groups and to set up the garden. This new concept was bigger, bolder and more challenging.

GRA had recently purchased two and a half acres of land, with the intention of feeding 70 orphan families in the local community, provide employment and an income stream. All within a sustainable permaculture framework.

Kinesi is a small fishing village on the eastern shores of Lake Victoria. Twice a year the great rains that deluge the Serengeti flood into the great mara river. Kinesi is on the mouth of that river. It takes 45 mins by boat to run from the large local town of Musoma to Kinesi. When the lake is flat, it is a beautific bargain at a little over US$1. When the wind howls across the lake from the east, you check your insurance policy and look nervously for a zip lock bag to cover your laptop.

In Australia, I’m a permaculture designer. In Africa, a permaculture ‘expert’. I love this country. I arrived four days prior to have a handover with the ‘expert’ from Zimbabwe. By the time he left, I had not set foot upon the site or even met my new team. Africa.

The site had been active for three months and the full time team of 12 had been busy. The hectare site had been a blank sheet of heavily compacted grazing land that sloped down to the big lake – some salt affected. The site had been swaled and planted out with a variety of legumes, perennial herbs and vegetables. While the region is in the wet/dry tropical region of central Africa, constituting two wet seasons, our plot had all the hallmarks of an arid design. With the wet season officially underway in less than a week, it was time to hustle.

As is typical in many denuded landscapes, a lower site has to handle a lot more water than that which falls upon it and this one was no exception. A week later we found out.

The first rain episode was a doozy. The lead berm blew out and took a lot of the bean crop with it. The salt exclusion drain worked very well and banana pits filled to the top and began slowly drowning the little suckers. In the next week we made rapid repairs to the wall, removed all the banana suckers from the swampy land at the bottom of the plot, and found a novel solution to release the pressure from the top trench.

Expanding upon the idea of a co-joined circle guild, we redesigned the blank eastern boundary to incorporate a descending array of pits. Acting as a spillway, we engineered the top swale to flow into possibly the largest flow form in Africa. 12 descending pits – each 2m x1.5m x1m deep – very effectively shed the water from heavy rain events sending it cleanly and rapidly into the lake. When the system is mature and infiltrating water more effectively, this can then be shut off and the pits filled with water hyacinth and used more conventionally.

While we were developing the garden, a separate team was constructing a compressed earth, sand and cement building at the top of the site. I observed one day that while the garden team was technically creating a facility to feed the orphans, it was the large structure at the top of the site that was drawing the lions share of the attention. Pondering this, I recalled some advice from a associate many years ago. He said “If you want to get respect in Africa, you have to create something big.” This had been my experience also.

Almost central to the plot was a slight depression that had remained very wet for the past month despite light rains. Of course with enough labour we could have created diversion drains, excluding the water. Or we could guide the water into an aquaculture pond.

While Furuno wrote eloquently of the ‘Power of duck’, little is mentioned of the power of hoe. In an amazingly short time, our hard working group excavated a pond 10 x 15 metres that, while lacking the dramatic presence of a excavator, gave the pond an individual presence and place that no machine could match, helped in no small part one joyous morning when the team instructed one the Mzungus (white man), Phillipe, to dance local style – the ensuing rapturous laughter echoing off the pond wall.

Three weeks later, a pond was completed with a capacity of 150m3, capable of producing approximately 300 mature tilapia every 3 months. Ducks will be incorporated into this system with a spillway on the up slope directing the nutrient rich water gently down the side of the pond to an on-contour wetlands area where taro and rice were planted. The overflow from the header tank will maintain a continuous supply of water to this system and if the windmill fails, the pond can be drained, the fish harvested and the pond used as an additional wetlands area to grow rice or tubers.

While we had 12 full time members, on Friday all the families of the orphan children came in and it was not unusual to have over 50 members digging, harvesting, laughing and singing. With the first harvest of Chinese cabbage came the first departure of mounds of green piled upon heads and bicycles. And great celebration.

Three months can go by very quickly in Africa. And in the tradition of grand farewells and cultural exchanges, the final day on site was a morning of firsts – my first time cooking breakfast for 45 people, and for the team, their very first pancake.

So where next? GRA’s intention is to use the site as a base and from here to spread the knowledge and benefits of Permaculture out into the community and then to greater Tanzania. Now with a strong and successful structure within the fence, the group is now establishing permaculture gardens in the local community using the experience and guidance of Julious Spiti, a consultant from Zimbabwe.

GRA has also just released a documentary on this project. Click here for an inspiring peek at this unique project and inspirational group.

Enjoy.

In August 2008, my wife Michelle and I returned to Calgary, Canada, after spending one year traveling abroad in search of sustainability solutions. With backgrounds in mechanical engineering, our “sabbatical” started off in Denmark – we were drawn there by the lure of technological solutions to energy issues. After several months of volunteering and filling our brains with information (wind energy, solar applications, passive buildings, biogas, plant oil engines… and more) we ended up back in North America prepared to explore the U.S. and Mexico in our plant-oil powered Westfalia.

We knew that something thus far in our sustainability search was missing and were starting to suspect that the missing link might be permaculture (although we didn’t really know what it was quite yet). Our travels brought us to several eco-sites, including an ecovillage near Mexico City. We stopped to do some WWOOFing at a permaculture farm and then headed further south to visit the indigenous Mexicans of the Chiapas, interested to learn about their agricultural practices. An Earthship workshop and geodesic greenhouses in New Mexico and an education center and CSA project in Colorado to name a few other adventures. And to culminate this amazing year we signed up for a Permaculture Design Course at Bullocks Homestead in Washington. The entire experience was nothing short of amazing.

Next task – put all of this information to productive use! Oh boy.

Luckily, my mother-in-law is a good sport and agreed to allow us to use her home as an outlet for ideas and a test case for a permaculture transformation project. Our goal – grow as much food as possible on this urban site and retrofit the home to reduce fossil heating energy by 90%.

Our first task was to asses the property and get productive food systems up and running. We invited friends and family over for a work party, sheet mulched the yards and planted over 100 plants in the front yard mimicking a forest ecology. As we were covering the yard with heaps of composted manure and cardboard the neighbours would slow down as they drove by in awe to see the vast quantity of materials and the number of people running around like ants building a nest. By the end of the day we had a fully sheet mulched back and front yard and a food forest ready to burst next spring.

In the spring we decided that our garden needed to have some swales and trails – shovel in hand we got to work digging. Within a day or so we had shaped our garden beds, filled the trails with mulch from a local arborist and got ready to plant the garden once we were sure that there would be no frost. Calgary has very limited precipitation (300mm) and only about 100 frost free days so we had to be on top of the garden as soon as we were able to make sure we didn’t miss and inch of rain or a day of sun. In late Spring we covered the garden with 20kg of inoculated field pea and shortly thereafter planted the rest of our garden with seedlings started earlier in the year.

With the garden progressing on its own we started on the energy retrofits. Our primary focus was on improving the thermal envelope, heating appliance and thermal mass of the building as we had been inspired by a previous visit to the German Passiv Haus Institute while in Europe. The first project was to blow-in one meter thick of cellulose insulation into the attic. Although the salesman thought I was crazy (new built homes usually have 20-30 cm), I wanted to meet the Passiv Haus Standard with an R-value of R70. Also, cellulose is relatively inexpensive and is an easy “do it yourself” project.

Next we went straight to work on siding of the house. Being that the home was built in the 70’s the wall insulation was approximately 1.5” thick fiberglass insulation (R8) and leakier than a sieve. We first removed the siding, sheathing, old mouldy insulation and vapour barrier to expose the studs and plywood inner wall. Next we blew-in high density foam into the cavities between studs. To prevent thermal bridging from occurring through the studs we added a layer of 2” rigid foam sheathing before replacing the siding. And it only seemed fitting that the new siding color be green! The steps above reduced our air infiltration over 5 times and brought our net R-value from 8 up to 31.

We then installed triple glazed low emissivity & insulated fiberglass frame windows. These windows have a net R-value of R7 which means that they act as a thermal appliance and allow more energy in than energy lost per annum.

Another project we managed to squeeze in was the basement. The basement has also always been very cold in the winter in part due to the lack of insulation in the floor. We attacked this problem by laying a subfloor of rigid insulation.

Based on these upgrades, I calculated that we could replace our 29 kW furnace for a 3 kW one. However, when researching furnace options, the smallest available on the market is a 95% efficient 15 kW. This certainly illustrates how poorly we build our homes!

The retrofit is almost done with a few minor exceptions. This summer we will be installing a solar hot water system to heat all of our domestic water. With the siding off earlier in the year we also took the opportunity to install connections for a future grey water system to feed our new garden.

And so, we have learnt some great lessons from our transformation project and are excited to see how the house performs over the winter. Most exciting of all – our neighbour has requested that we extend our front yard food forest into his yard (he never did like cutting grass). Perhaps we will inspire many others in our neighborhood to do the same. 

The ‘Adobe House’, El Manzano’s ecological demonstration house.
All photos © copyright Craig Mackintosh

In the middle of the little El Manzano village, on display to all in the community, is the ‘Adobe House’. This demonstration house is a project by Eco Escuela El Manzano to demonstrate to the community several low-tech but effective techniques for improving quality of life whilst reducing a home’s impact on the environment.

Houses made from adobe bricks are common in Chile, although, increasingly, like many ‘developing’ countries, people are turning towards energy disastrous concrete instead. The Adobe House was not purpose built – rather, it is actually a very old house that was retrofitted in 2008. It is thus a good example of what many villagers could do if they had a mind to.

I’ll share a few of its features.

Against one wall they built a simple conservatory. The earth brick wall absorbs heat during the day, warming the home, and radiates it back out during the night – to ensure an extended frost-free period for vegetables. Well positioned terracotta tiles or other high thermal mass elements can increase this energy buffering as well (even just barrels of water can do the trick). Though not incorporated here, another addition can be to add vents between the conservatory and the home to allow excess heat to pass into the house.

During the hotter parts of the year the ends of the conservatory are easily opened up.

Outside the house and conservatory there’s a trellis hung heavy in grape. It creates an excellent, and edible, shade area under which sits an outdoor table and benches for summer breakfasts and lunches. The foliage dies back during the winter months to let more sunshine through.

Next to this sits a fantastic earth oven. And yes, the bread was as good as it looks:

Other elements include the all-important manual pump for water – without which this community would have suffered dearly during the recent earthquake (see Part I) – and a greywater system for biologically cleaning household waste water, returning it, slowly, to the water table after several stages of natural cleaning.

Potty Training

The ‘centrepiece’ of this demonstration site, however, is this:

A composting toilet (or ‘dry toilet’ as they’re called here)

This elevated, dual-chamber throne room (similar to the one at Zaytuna Farm) serves as the home’s fertiliser collection station. When enconsed therein, or thereon, as the case may be, the room is notable for its lack of odor. Any odor.

Although composting humanure should be regarded as an urgent… um… call of nature everywhere (the world is running out of potable water, and yet we’re crapping in it, and we still haven’t come to terms with the significance of phosphorus recycling yet either), it is arguably even more important here in El Manzano.

I say this for two connected reasons: 1) most of the community here rely on ‘long drop’ toilets (simple holes dug into the ground), and 2) the water table in El Manzano is incredibly close to the surface – in many places barely a metre below ground.

In case the obvious eludes you – this means that these smelly, bacteria-filled repositories will be seeping into the water table…. Yes, this is the same water table they’re pumping water from so as to quench their thirsty lips. If it weren’t for the very low population density here I think we could be looking at some serious health issues.

The Eco Escuela El Manzano team are therefore turning the problem into the solution, by demonstrating how a potentially disastrous waste stream can instead become a resource. The Abobe House has a constant stream of students and interns residing in it – all of whom are building site fertility rather than contributing to water contamination.

Continue on to read Part V: The Design Stage

Please consider contributing to this worthy cause – you can do so via donation links on this page!

Further Reading:

• Compost Toilet – Farallones (237kb PDF)
• Compost Toilet – Minimus (459kb PDF)
• Urine-Diverting Toilet, Vietnam (3.4mb PDF)
• Low-Cost Compost Toilets (3.45mb PDF)
• The Humanure Handbook

Swales hold and soak water that would otherwise get away without doing anything positive for your property. In fact it can cause problems – like soil erosion.

Swales are critical features in the design of any permaculture project but most of the applications you see on youtube are broad acre properties and many people might think that’s what they’re reserved for. Not true!

Small swales are very useful in urban gardens and can double as footpaths. Have a look at my video of Geoff Lawtons kitchen garden, which is a great example of how to improve your urban garden.

Much Love! Pat

One of 55 eco-friendly homes nestled amongst newly established gardens

An hour or so south of the Sri Lankan capital of Colombo is the fishing district of Kalutara. Although only one of many regions hit by the 2004 Tsunami, post-disaster relief efforts here were unique in that Sarvodaya determined to use the situation to create Sri Lanka’s first eco-village.

Designed with the technical advice and guidance of world renowned Australian permaculture experts Max Lindegger and Lloyd Williams, who are affiliated with Ecological Solutions Inc. and Global Eco-village Network (GEN), the village has become a model of sustainable development.

The Sri Lankan government allocated a parcel of land situated five kilometres inland for the purpose, and financing for construction came via Sarvodaya as well as the American Jewish Joint Distribution Committee (AJJDC), the United Nations Environmental Program (UNEP) and the Asia Pacific Forum for Environment and Development (APFED). The combined gifts culminated in the construction of Lagoswatta – a model eco-village, situated on a gentle five acre slope bordered by rice fields, that is now home to 55 families from three villages in the area.

I was of course very keen to take a look, and so after winding our way from the coast, through small farmlets and a rather beautiful and shady rubber tree plantation, I arrived in Lagoswatta for a brief look.

Beginning in April 2005 and completed in 2006, an important aspect of of the work was the involvement of the intended residents in the construction process itself – providing an excellent opportunity to build a sense of ownership and self-determination for their future, whilst giving survivors a sense of purpose that helps them deal psychologically with trauma, loss of loved ones and their subsequent dramatic change in circumstances.

Each earth-brick home in Lagoswatta is virtually identical, measuring about 46 square metres (500 square feet) and consists of two bedrooms, a living room, kitchen and sanitation facilities. Each home has its own garden, and practical involvement of residents are positively encouraged with training in composting, gardening, recycling and also maintenance of the solar panel and battery that provides electricity to each home – something many residents never had before. Homes are also equipped with a recycling receptacle and on the edge of the village is a small recycling station where materials are separated and stored for monthly collection. The project also included a Subterra biological soakage system for household greywater.

Water for drinking and irrigation is one of the biggest problems Sri Lankans face. Construction for Lagoswatta thus included fourteen rainwater harvesting tanks to collect roof run-off, five drinking wells and two communal bathing wells.

An important aspect of design for any eco-village are those that encourage community interdependence. In addition to housing, a multi-purpose community center was built that includes a doctor’s office (manned on Mondays), library, computer room, a childcare/Montessori school centre and a playground – all encouraging community interaction and the pooling and development of the creative abilities of individual villagers. Programs assisting in social mobilization and livelihood support foster this development as well.

A boy plays in the community childcare centre

The edge-of-town recycling station – emptied monthly

One aspect of village life I found interesting was that, unlike other Sarvodaya villages, where the very first stage of development is ‘awakening’ to the Sarvodaya principles based on earth care and the ten basic needs, the villagers of Lagoswatta were somewhat thrown together suddenly at a time of extreme stress. Additionally, many of the villagers were previously fisher folk, so once moved from the coast to Lagoswatta they’ve had to take on a whole new existence. Whilst villagers on the whole largely seemed content and adapting to their new surrounds, it was clear to me there wasn’t the same industriousness and cohesion found in some of the other villages who had opted to join the Sarvodaya network out of acknowledgement and appreciation over time of the principles that forms the basis of the movement.

In other words, these people were somewhat thrown together out of necessity, rather than inspired choice.

A Lagoswatta villager harvests compost from his bin

Practical examples of this could be seen by observing the state of different gardens in the village, where some were making excellent use of their land – cultivating quite a diverse range of fruit, vegetables and herbs and developing a lovely shaded environment that is a major advantage in the tropical heat – while others were making merely token efforts.

Some villagers were making excellent use of their garden space

I spoke with a few villagers about how well their solar system worked. One man spoke despondently about how after only four years the battery had already failed and he couldn’t afford the 15,000 rupees to replace it. Considering this man didn’t have power in the shack he and his small family lived in prior to its destruction, I was conscious of how this ‘upgrade’ in their life was making them dependent on polluting technologies that were too expensive for them to maintain. When I mentioned the failed battery in a neighbour’s house, it was explained to me that the first man had not been maintaining the battery as he was told (topping up with water) and so killed it from neglect. Considering this, I remembered that that particular man’s garden was also largely non-existent, indicating either a general lack of pro-active interest or difficulty in adapting, and it made me appreciate all the more the importance of Sarvodaya’s stepped program that prioritises individual transformation at its base.

Each home has a battery that stores power from a small roof-mounted
solar panel. The only appliances for most houses are normally only lights,

a radio and/or television.

As they say, a house does not a home make. In the same way, a collection of buildings and people does not an eco-village make. It became obvious to me that you cannot just lump a divergent range of people together and call them a ‘community’. A truly successful community requires some planning at a spiritual level to facilitate cohesion – and this centres in all involved being inspired with a sense of positive purpose and collectively shared goals. Disasters like that which gave birth to Lagoswatta obviously do not provide the luxury of time for such considerations, but I think this is an important facet to consider wherever possible.

Villagers said their conditions were improved – homes were warmer in winter,
cooler in summer, and power, water and garden features were all appreciated.

The good news is that Sarvodaya’s efforts in this regard continue to this day, and Lagoswatta has become an excellent model for not only Sri Lanka but also for village development and disaster relief efforts worldwide.

Continue on to read Part VIII….

The community centre is appropriate for culture and climate

The community library was spartan, but it’s a start

Composting toilets are culturally unacceptable to Sri Lankans, so Lagoswatta
utilises septic tanks for black water. Outside are rain-fed washing facilities.

A typical Lagoswatta kitchen. Some homes house two or three families, as
families would open their doors to relatives struggling after the disaster.

A children’s park completes the picture. The sign reads:

"This park is a gift to the children from the American people."

It’s taken a while to find the time to sit down and report on Part B of our earthworks here at Rosella Waters, near Cairns in far North Queensland. Phase I Part A was documented whilst the process was taking place. This latest update however will rely on memory and hurried notes made during the process, together with numerous photos. Large excavations such as the two large dams we constructed in part A are considerably easier to direct and far less time consuming than the finer detail work using smaller machinery as we experienced in putting in Part B.

Once again we had an excellent earthmover that came on the recommendation of the guys who did the two large dams. Sparky, as he is known, is a very knowledgeable and experienced earthmover, having spent a great deal of the last 40 odd years driving a 46 tonne excavator, building large scale dams, roads and “opening up new country”, as the saying round here goes. Now he runs a private earthmoving business and has at his disposal an 85HP bobcat and a 4 tonne mini excavator with numerous attachments. All of the following work was done with these two small machines.

The first part of the process in Part B was to construct a gabion rock wall at the very top of our system, in the gully that feeds our two dams. Previously, we had done a catchment analysis and based on the 1000mm of rain we receive per year, we arrived at a figure of 5,000,000 liters moving through it. We used this figure to calculate levels and engineer our spillways, level sill heights, the freeboard on the dam walls, trickle pipes, lock pipes, etc. The gully in question begins on our neighbour’s property. It is fed from the hill behind it and also from the diversion drains the road department puts in on the dirt road leading to our front gate. The catchment is predominately regrowth after being cleared 30 years ago with two dozers and a ball and chain. The catchment area is not a well functioning bio-diverse eco system and as such there is little water infiltration and a lot of sheet flow that brings top soil/sediment run off into our system. During the wet season of 2008 we did a small trial by hand building a rock wall just inside our fence line to get an idea of how much material would be trapped and how long it would take to fill up. After only 3 rain events, the small rock wall was fully backed up with silt 1.5 feet deep and the moisture remained just under the surface of that material well into our dry season. With that experience and the slight scar constructed at the back of the Lap Pool dam during its construction, we decided on a larger than first thought gabion, to (a) repair the damage caused by the construction of the Lap Pool dam (b) trap silt/top soil and sediment, preventing it washing through our system and ultimately ending up on the Great Barrier Reef, and (c) provide a small scale example of a solution to dry eroded gullies, that run like rivers in the wet, utilizing a “waste” product of local agriculture.

The “waste” product I speak of are the mountains of volcanic rock that many farms in the area have piled up in massive windrows. Farmers spend up to $4000 an acre to pull them out in preparation for planting avocados, potatoes, mangoes, bananas, sugar cane, etc. Rosella Waters sits right on the edge on an ancient lava flow so the farms that surround us are littered with such rocks, some as large as a car down to rocks as small as a grapefruit. We approached our neighbours up the top of the hill, who grow avocados and mangos, and who had recently put in a mass planting of new trees. Prior to that they had a 20 tonne excavator and dump truck working for a week to pull every rock out. They followed this by traversing over the land with a pickup and five workers pulling the grapefruit sized ones out by hand. Anyway, they were more than happy for us to go onto their property and select as many rocks as we liked from the windrows, which they had conveniently separated into different sizes.

Gabion rock wall trapping silt/sediment & top soil

The cost in building the gabion was therefore the time for Sparky to load up the individually selected rocks into his tip truck and then place them one by one with a claw on the end of his excavator arm. The process took two days in total and we estimate that it cost us close to $1800 to build. As we had large rocks to work with we decided against both “keying in” the base of the gabion wall into the side of the gully and constructing a net meshing to encase them in.

The volume and more importantly the velocity of the water coming down the gully in this case didn’t necessitate us doing either. Choosing the largest rocks first, we placed each one exactly where we wanted to create a firm base on which to construct the wall. It was built much in the same way as a dam wall is built, starting out wide at the base, six meters in this case, and tapering up to two meters wide at the top. The height of the gabion is nearly three meters. After placing each rock, Sparky would firm it down, swivel it around until it was firmly wedged. This in itself is more difficult than it might seem and does take time, but it is VERY important to get right. In all, the wall required 7 full dump truck loads of rock to construct. Once the main frame of the wall was complete we got another two loads of grapefruit sized rock which we have since placed by hand to smooth out the top of the gabion, thus providing a great access path across the gully that we can push a wheel barrow across, drive an ATV over or lead a goat and cart. To repair the scars at the side of the back of the Lap Pool Dam, just in front of the gabion wall, we placed some large rocks on the ledge and back filled behind the rocks with some top soil we had had set aside from the construction of the two dams. This was immediately cover cropped with cowpea and a crotalaria variety called gambia pea. All of the seed we used to cover crop was bought from a local seed merchant as seconds, which means there is a low strike rate (around 40%) but at $1 per kilo and having used the correct inoculant, we gained excellent coverage and stabilized the area. It’s important to remember that seed is the cheapest herbicide!

The next element we tackled was the overflow swale and spillway connected to the larger Mushroom Dam at the bottom of the property. We decided that after completing the gabion it would be best to start at the bottom of the system and then work our way back towards the front gate so that by the time it was all done, Sparky could load up and head off without risk of doing any damage with his machinery.

The first swale was only fifteen odd meters in length and had a level sill spillway half way along it that would spread the overflow of the system over a 3 meter wide area right on a broad ridge point, making it very safe to discharge and presenting no danger of causing an erosion gully. The construction of this small element proved to be a major turning point in our working relationship with Sparky. In the end it took the best part of a day to complete, due to a number of factors including our newfound language barrier. There were some important miscommunicated terms that needed clarification as we went: level sill spillway, back cut, swale, swale mound, swale dish, bottom of the swale dish and most importantly LEVEL. The idea that we wanted to construct something that didn’t run and was in fact perfectly level and on contour was quite a paradigm shift for Sparky, as in his words he had “spent his whole life draining landscapes” and what we wanted to do was quite the opposite.

The swale needed to be constructed on a steepish slope and we decided that we wanted it to hold 300mm of water in the base and have the top of the swale mound 800mm high – thus a substantial 500mm freeboard on the swale mound. The freeboard on the dam wall is one meter, so if ever there was a chance of water spilling over it would go over the swale mound first. It is unlikely to occur as we have “over engineered” things, but if it did the swale mound can be repaired with a shovel unlike the dam wall! What we soon discovered in constructing the swale was that due to the slope of the land we just wouldn’t have enough material to make the swale mound as high as we wished. The answer was to dig further up the hill from the back cut, as gently as possible, in a 1:1 cut. We didn’t want to dig too far up the hill so we adjusted the level of the swale mound back to 700mm high and with a three-meter long level sill spillway, the swale mound still wouldn’t be at risk.

First swale constructed leading off the Mushroom Dam

The data records for the region showed that the largest single 24-hour rain event in the last 30 years had been 284mm. We rounded this out to 300mm and built the spillway to be able to deal with ½ cubic meter of water per second. Together with another spillway on the swale connected to the opposite side of the dam wall, we have more than ensured the dam wall’s safety. Another safety margin we designed into the system was a 110mm lock pipe set at the bottom of the Mushroom Dam wall. The lock pipe is 27 meters long and goes right through the bottom of the wall. On the outlet side there is a butterfly valve, which can be opened wide in the event that the spillways aren’t coping. At the bottom of our system, and being our primary aquaculture dam, it also means we can drain this dam if needed. The dam also faces West, which is likely to be the direction of any fire entering our property, so in the event of a fire we have the added security of being able to drain 2.5 mega liters of water in that direction.

For ease of construction we built this first swale with the 85HP bobcat, equipped with a 1.7 meter wide tilt bucket. Time is money with earthworks, so we decided to make the swales a bucket width wide. Sparky started by running across the slope with his bucket following the back cut line we had marked out, corresponding to the high water mark of the dam. The spill was flicked down slope forming the first part of the swale mound. Once we had the basic shape and marked the position of the level sill spillway, Sparky used his tilt bucket to scrape beyond the back cut line up the slope to get the material we needed to gain the swale mound height we were after. We also took quite a bit of material from the area leading onto the dam wall, progressively cutting back to smooth out the sharpness of the cut. Sparky did a great job and we can easily drive through this area and up and onto the dam wall, giving us access to the other side of the property. The swale runs dead level at 300mm deep all the way through, from the exit point at the dam to the end of the swale itself. On the final scraping run we asked Sparky to tilt the blade slightly down slope in the swale dish, meaning that water will be predominated into the swale mound during rain events. With our first swale complete, fully seeded and earthmover trained we we’re ready to attack the rest of the design. Together with a mix of gambia pea, cow pea and pigeon pea we also planted sweet potato cuttings, aibika, cassava, pumpkin seeds, etc… giving us full cover leading into the wet. In the last few days we have started to receive our first rains in 9 months, so now we have a good base in which to begin our major plantings.

The next swale was a short one connected to the opposite side of the dam wall. It was constructed in the same fashion and care was taken again to ensure a smooth driveway leading off the dam wall for ease of access. With not much room to play with within our boundary line, the swale was extended right up to the fence line with our neighbours and the three-meter level sill spillway will serve as discharge of excess water into the creek below, and also as access to behind the dam wall and our Zone IV area of the property.

Moving further up the slope, we then tackled the 25-meter long swale connected to the Lap Pool dam. With this swale we had a few important decisions to make. Firstly it was going to be the Lap Pool’s only swale and only level sill spillway, the overflow from this leading to the Mushroom dam. The placement of this level sill was therefore vitally important as it would be the major source of water that fills the Mushroom dam and we also have future plans for structures connected to the 6m x 3m jetty we placed on the dam. We saw the opportunity for the level sill to be a feature and a potential wet/dry growing area, in close proximity to the jetty and eventual cabin connected to it. We decided to step the overflow down into a further two level sills before it entered the Mushroom dam.

The step down spillways leading overflow from the Lap Pool Dam swale into the Mushroom Dam. Jetty posts in waiting.

In this way, we slow down the volume of water, create further edge and add an aesthetic feature in the process. The level ditches are slightly wider than the level sill on the swale itself and together with generous amounts of cover crop seed, we planted clumps of vetiver grass to further stabilize the area and slow down water flow. We used the same technique on all the level sill spillways. With such an abundance of rock at hand and a couple of quite steep spillways to stabilize, we saw this as our best option. On two steep spillways, we planted out clumps of vetiver grass across the slope, starting at the top and offset all the way down. Then we placed rocks from the bottom up, starting with larger rocks in an arc, wider than the spillway, followed by smaller rocks all the way up the spillway wall face. We left a 200mm space around each of the vetiver clumps and now 3 months later we have a very stable, rock wall face to our spillways, with large clumps of green vetiver grass breaking up the brown.

Back on the Lap Pool swale we asked Sparky to dig ½ meter deep x 1 meter long x ½ meter wide ditches within the swale dish itself. These ditches will hold water for longer than the rest of the 300mm deep swale and as such become growing zones for some wet crops. We now have these ditches planted out with Taro, with water chestnuts on the edges, all of which is shaded by bananas growing at the inside edge of the swale mound.

Lap Pool swale with newly planted Taro and water chestnuts in the pits and banana on the edges.

Again the whole swale was cover cropped with cowpea, Gambia pea, pigeon pea and dotted with cassava, Aibika, sweet potato and pumpkins. The larger long-term support species and variety of fruit and nut trees are now ready to be planted. We had considered putting all of plantings in at the same time but with no rain at all for close to 9 months we decided to get cover crops and shorter term nitrogen fixers going and wait for the beginning of the first rains before putting them in. The earthworks couldn’t be put back to a more appropriate time due to the availability of machinery.

The rice paddy system was by far the biggest challenge. To look at now, it seems all we have done is push a little dirt up to make a wall and dig a couple of holes for the ducks to live near. In a sense that’s true, but the process of constructing the 1:300 diversion drain from the Lap Pool dam to a duck pond connected to a rice paddy (the overflow of which runs along a diversion drain with a 20mm fall over 20 meters, to another duck pond connected to another rice paddy, the discharge of which drops down into a 25 meter long bio-filter which is itself a level sill spillway), dropping water into the Mushroom dam wasn’t that simple! Plus, the overflow of the second duck pond, leads to a short swale with level spillway that drops down to a 20-meter long swale, the spillway of which also drops into the bio-filter before being discharged into the Mushroom dam. Phew.

The rice paddies with bio-filter below. The beach area is on the edge of the Mushroom Dam with the back side of the Lap Pool Dam wall behind it.

A great deal of gravel road base material was taken out of the rice paddy area and we used this to repair/construct a proper ringed access road, our main access road on the property. The road has now been graded correctly so that water will run into drains leading along side it directed to water storages. On the road we have placed 150mm x 50mm x 4 meter long blue gum planks in sets of two, 4 inches apart, at an angle across the road, every 10-12 meters. We first heard of this idea from Rainbow Valley Farm in New Zealand who has the same system on much steeper roads. As water runs over the road it only has a short distance to run before it drops down into these drains that run across the road at a slight angle. By not allowing the water to build up speed over the road surface the material stays on the road rather than down the bottom of the hill, with obvious benefits.

The diversion drain leading to the 1st duck pond needed to fall at 1:300 and be set low enough in the Lap Pool dam so that it was the first water to leave the dam as it filled. We can regulate this fact by capping the end of the 150mm pipe. The level at which we set the150mm diversion pipe was 450mm below the high water mark of the dam which also corresponds to the level of the level sill spillway. That is 150mm lower than the depth of the swale and the level at which water exits the dam into the swale. As I said, setting the pipe at that level ensures we can control when the water heads to the duck ponds. We have a 30,000 L concrete water tank connected to our shed with approximately 100,000 L of potential roof catchment. We needed to decide what to do with the extra 70,000L. In a minor brain wave, we came up with the idea to pipe the overflow through a 90mm pipe down the side of the tank, under the road and into the 150mm diversion pipe with a t-piece. At the entry point into to first duck pond, we have rocked the spill and next to the 150mm diversion drain pipe we have another 150mm pipe under the road that collects all the water in the drain running alongside the road. At the end of the drain along the side of the road we have dug a meter deep silt trap, concreted the base and placed a grill over the top. This will keep silt out of the duck ponds and provide another source of potting mix from the material that does ultimately come from the road.

The main issue we faced with the levels we were dealing with was to get the duck ponds as high up the slope as we could, leaving us room to put in the proposed rice paddies. The duck ponds would end up being quite small as a result and have a 800mm slope at the back of them from the ridge road. We saw this back slope as another opportunity to be creative and decided to step this down in 300mm wide ledges to the high water level of the ponds. The end result is a duck pond amphitheatre on both ponds! This stepped area will be fully planted out with duck habitat and forage, shading the ponds in the process.

Duck ponds at the back of the paddies, connected by a diversion drain. The amphitheatres at the back of the ponds are well cover cropped and stable.

The two ponds are connected by a diversion drain that runs from 1st pond to 2nd pond, with a 20mm fall over its 20-meter length. This isn’t a great deal of fall, but it’s enough. It has meant we have been able to keep the 2nd pond up as high a possible to give us room for the paddy below. The water from the duck ponds are released into the paddies by way of gates we picked up from an old rice farmer up here. They used to grow two crops a season using the channel that leads from Tinaroo Dam as a source of their water. One of the reasons they gave it up was when the cost of water went from $8 p/ML to $18 p/ML. Now they flood irrigate sugar cane instead. We swapped the four gates for a case of beer and made metal plates that slide into the 3mm gap in the concrete gates, to control the flow of water. The same gates are used at the exit end of the paddies, to discharge the nutrient rich water into the bio-filter below before it heads to the Mushroom dam.

The bio-filter that acts a level sill, taking nutrient rich water from the paddies as well as the swale in the background at the base of the chicken tractor system, overflows into the Mushroom Dam.

The two paddies are separated by a meter wide bund and surrounded by a meter wide, meter high bund with a slight grade. All of this will become a growing zone for duck forage, mulch and some soft fruits such as pawpaw and banana. The meter high bunds, once planted out, will become a living fence keeping the ducks in the paddies during the rice-growing season. We plan to grow rice using the integrated rice and duck growing system I had learnt whilst living with Takao Furuno and his family in Japan. Takao is a social entrepreneur with the world economic forum with his rice duck growing system and has an excellent book out through Tagari publications titled “The Power of Duck”.

The short swale connected to the second duck pond drops down into a longer swale, which will form part of our chicken tractor system. This 20 meter long swale lies at the bottom of the contour chicken runs and borders the Mushroom dam. It’ll take excess nutrients from the chicken system and grow some large trees on the north side of the dam, providing shade. Due to this swale being constructed on less of a slope than the first, it was built with the four tonne excavator. Working from the downward side of the swale, the bucket cut on the back cut line and the spill was dropped to create the swale mound. Following Sparky along with the laser we ensured that the swale dish was 200mm level all along. It doesn’t need to be within a mm but it does help to make the dish as level as possible so as to get an even distribution of water along the swale in lesser rain fall events. Obviously the best way to check that level is to fill the completed swale with water and adjust accordingly with a shovel. It is cheaper to do this in your own time than to pay $100 an hour for a 4 tonne excavator to do it.

“Hairy Harry” stands tall on the island at the back of the Keyhole Dam.

The final element to put in was the Keyhole dam at the entrance to our property. We named this pond the Keyhole, as it is the key to the system that connects water on both sides of the property. The Keyhole sits on a central ridge that dissects the property and the idea was to create a small water storage in our Zone 2 area that can move water through either the system described above or to future water storages on the river side of the property, or both. We decided how large a storage of water we wanted and marked out the approximate position of the dam wall for Sparky to follow. We set a target level for our high water and corresponded this to the position of the two swales that were to direct water to the Keyhole via 150mm pipes placed under the access road. The wall was built using the bobcat, layering wetted clay followed by numerous track rolls with the same machine. Using the excavator to dig the hole of the dam, material was mixed using the tilt bucket with me standing close by, hose in hand, making sure there was the right amount of moisture to make the clay bond. Dam and pond walls are all about compaction and with enough of the right clay, a little mixing if the material is good and bad, and the correct amount of moisture, things should seal. We decided to create a small island at the back of the Keyhole as an aesthetic feature, duck habitat and for the fact that the palm we’ve named “Hairy Harry” was too good looking to lose.

Once the Keyhole was built with a 400mm freeboard on it, we set about marking the back cuts of the two swales that were to connect to it. The Mediterranean swale (so named due to quite granite soils in that part of the property) leads out towards the header tank and drops its spill down into the Lap Pool dam. It is connected to the Keyhole via a 150mm pipe, under the road with a slight 20mm drop towards the pond so as to not get stagnant water sitting in the pipe.

The Mediterranean swale connects to the Keyhole Dam via a 150mm pipe under the main access road. The level sill spills water into the Lap Pool Dam below.

The end of the pipe can be capped, if we wish to keep water in the Keyhole dam and direct any overflow via the 150mm pipe under the road on the other side that connects the Council swale to the same dam. We called that one the Council swale because its main catchment comes from a slight improvement to the dirt road the council recently graded. It was graded sloping towards our fence with no drain so in large rain events we would get large sheet flows of water moving through the landscape causing unnecessary erosion. We asked Sparky if he wouldn’t mind creating a little spoon drain 100 meters up to the neighbours gate entrance and directing that water through the culvert under our road entrance. The five meters beyond the culvert to our fence line continued as a drain before entering our property where it then becomes a level swale directing a substantial volume of water through the 150mm pipe, under the road, into the Keyhole dam and ultimately through our entire system.

Considering the volume of material we are likely to receive from the dirt road, we placed a 200mm deep x three-meter wide silt trap just inside the fence line. This can be dug out by hand when necessary. The level sill spillway of this Council swale directs overflow to a gully, which in future may become a dam or a large gabion, subject to future test holes to check for clay content.
Either pipe in either swale can be capped to control the direction of water movement through our system. This small dam feature is something we are really happy with for its aesthetic beauty and complex simplicity in functionality.

This spoon drain runs 100 meters long and will direct a large amount of water through our system via the Council swale that connects the Keyhole Dam.

For our first major earthworks the complexity involved in the design was substantial. It was quite a big undertaking, made even more so by the birth of our second son Dylan smack bang in the middle of it all. At this point I must give special recognition to my darling wife Georgie who at 41 weeks pregnant, kept us fed and watered, took all the photos and spent considerable time standing there with FRED ( Forever Ridiculous Electronic Device) i.e. the lazer level staff and receiver, in 33′C tropical heat. We took close to a year observing the site, designing, listening and talking to others, re-designing and planning the earthworks and the immediate repair work after they’re done. Once the earthworks began, concept became reality and the two can be quite different no matter how good the planning. Each evening after Sparky had left we spent time talking things over and making decisions for the next day’s work. We gave our laser level a really good working over, it has been a great investment; I don’t imagine we could have done all that we did without it.

Now that the mainframe infrastructure is in place, a little water is in the dams and the site is green with cover crops, the system has literally come alive. From seemingly nowhere frogs have descended upon the water storages attracting ever-increasing numbers of birds. The place must look like a red-light sale at a discount store – a hydrated green oasis in an otherwise dry landscape.

Overlooking the system from the header tank. A transformed landscape.

A natural spring we knew existed has started to recharge with the water in the swales from irrigating the cover crops. It moves through the sub-soil leaking out into the side of the dam. Our hope is that this recharged system will help to keep the water level more constant in the Mushroom dam by offsetting any evaporation.

In all, the earthworks took close to two months to complete from start to finish with a total of 16 days of actual earthworks involved. With the start of our seasonal wet season rains upon us, the next three months or more will be spent busily planting, planting and more planting. We know Sparky is coming back when the wet really hits – we made a pact to sit down with a beer together in the pouring rain and watch the system operate in full flight. Through a local NRM group we are also planning an open day, for local farmers to come and see the system. These major earthworks are just the start of a great adventure in the development of our Permaculture demonstration site for the wet/dry tropics of Northern Australia, Rosella Waters.

Download: You’ll see the option to download the 913 megabyte MP4 file at bottom right side of this page.

YouTube: The video can also be watched on YouTube, in four segments, here, here, here and here.

Greening the Desert II (including Part I) – Greening the Middle East
(Duration: 36 mins)
Tips for playing: If it’s slow to load, turn off High Definition (HD) on the player.
If you still have problems, click play (on low or high def) and then after it’s started,
click on pause. The video will then continue to buffer into your computer.
Play once fully loaded.

I would like to take the opportunity to thank Kelly Kellogg at this juncture. Kelly donated initial funding that enabled the purchase of the land for the Jordan Valley Permaculture Project site (aka ‘Greening the Desert – the Sequel’). But, upon watching the Greening the Desert Part II video, Kelly was inspired to donate an additional $20,000. These gifts are very encouraging to us as we try to solve problems at source (teach a man to fish…). Others who may feel inspired to donate to help us move this work forward faster can do so here.

A little background on the video follows:

Children in a school playground, Al Jawfa, Jordan Valley

When there’s no soil, no water, no shade, and where the sun beats down on you to the tune of over 50°C (122°F), the word ‘poverty’ begins to take on a whole new meaning. It is distinct and surreal. It’s a land of dust, flies, intense heat and almost complete dependency on supply lines outside of ones control. This is the remains of what was once called the ‘fertile crescent’. It is the result of thousands of years of abuse. It is a glimpse at a world where the environment – whose services provide for all human need – has all but completely abandoned us. This is a glimpse at the world our consumer society is inexorably moving towards, as our exponential-growth culture gorges itself at ever-increasing rates.

The original Greening the Desert video clip has been watched hundreds of thousands of times and has been posted to countless blogs and web pages in the datasphere. Although only five minutes long, it has inspired people around the globe, daring the lucid ones amongst us, those who can see the writing on the wall, to begin to hope and believe in an abundant future – a future where our survival doesn’t have to be based on undermining and depleting the very resources of soil, water, phosphorus, etc. that we depend on. The work profiled in that clip demonstrates that humanity can be a positive element within the biosphere. Man doesn’t have to destroy. Man can repair.

In the clip at top I introduce you today to Greening the Desert II. I shot the footage for this video last month (October 2009) and edited it on location in the Dead Sea Valley in Jordan – the lowest place on earth, at 400 metres below sea level. Much of it was shot in or near the village of Al Jawfa where I stayed, which is effectively a Palestinian refugee camp that has morphed over the decades since 1948 into something resembling a functional small town. It was first shown to delegates of the ninth International Permaculture Conference (IPC9) in Malawi, Africa at the very beginning of November and is now being released for general consumption. The video will take you to the original Greening the Desert site, letting you see its present condition after six years of neglect when funding ran out in 2003. You’ll also be introduced to our new project site – the Jordan Valley Permaculture Project, aka ‘Greening the Desert, the Sequel’ – and see some of the spin-off effects within Jordan from the influence of the original site; promises of much more to come.

The work we’re undertaking in Jordan is in accordance with what we call the ‘Permaculture Master Plan‘, where the project’s future is assured through funding from running educational courses. Project sites thus become self-sufficient, and self-replicating.

Geoff Lawton instructs students in a school yard in Jordan, one that PRI has
just created and begun the implementation of a design for, so its
many children can see, experience and learn permaculture first hand

Through this work we envision thousands of educational demonstration sites worldwide – all inspiring and teaching communities around them how to begin to tackle at root the massive challenges we now face after decades of short-term profit-based thinking has all but ‘consumed’ our planet and dismantled the social constructs that the human race has always depended on for its survival. Through this work we see desertification stopped in its tracks, and reversed. We see this century’s dire water issues getting resolved. We see productive work for millions in bypassing the irrelevant efforts of our ‘leaders’, to instead build a new kind of culture – a culture based on cooperative effort and learning. It’s a culture where its members have regained a sense of their place in creation, where they become land-based stewards of remaining resources; creating a culture where we at last find ultimate satisfaction – promoting and building peace and low-carbon, relocalised, community-based prosperity.

We have many such ‘Master Plan’ projects in various stages of development worldwide, and a steady stream of enquiries from people around the globe wanting to get involved and help widen this cooperative network. Perhaps it’s time you took a look at Permaculture? After all, do you have something more worthwhile to do?

Jordan Valley

Geoff Lawton and Darren Doherty are the two highest profile people in Australian Permaculture when it comes to broadacre water harvesting earthworks. They’ve both had success in some very tough environments, and yet it’s interesting that their styles are quite different, particularly when it comes to infiltration strategies.

This article is a short comparison of their approaches, along with an idea I had recently for amalgamating the benefits of each.

To help illustrate, I’ve put a set of boundaries on a section of a topographic map (figure 1.1). 

Figure 1.1 – Base Map

I realise that both Geoff and Darren would be salivating as they looked up the hill at the potential dam sites above, but I’ve deliberately left them out of the equation to keep things simple and limit the comparison to their infiltration strategies.

Similarly, although I haven’t marked it in, each of them would put in a small dam/wetland/silt-trap in each of the valleys to dissipate the flow coming on site and prevent their mounds blowing out.

Geoff Lawton’s approach

Geoff’s style for infiltrating water into the landscape is to use swales (often connected to dams but that’s another story). His aim is to catch water as high as he can in the landscape and use the dead level swale to spread the water across the length of the land. This water is held in the swale, giving it time to infiltrate into the soil, and it then plumes downhill, recharging the ground water for the benefit of trees planted below (figure 2.1).

Figure 2.1 – Soil water movement after swale infiltration
See this animation for more details

He often builds his swales with a bulldozer, resulting in a large capacity (eg a bulldozer blade wide and deep as in figure 2.2 – the back and front walls are battered on the subsequent passes).

 
Figure 2.2 - Front view of a bulldozer building a swale 

This is well suited to the sub-tropics where 50-100mm events are common and also in arid areas where the few rain events that occur can be a deluge. A large volume of water is held in the swale, giving it time to infiltrate into the landscape, for the benefit of the trees planted below.

A design constant we can work with is that water flows at 90 degrees to contour, both above and below the soil surface. Each large red dot in figure 2.3 represents an even amount of water that has infiltrated along the length of the swale. The red lines show the path that the water takes as it moves down through the soil profile.

Figure 2.3 Swale infiltration (red) path

Natural water flow in the landscape

A natural pattern in the landscape is that valleys are moist whereas ridges are dry. You can see this in the vegetation in any undulating National Park you go walking in, with lush, moisture loving plants in the valleys, and dry sclerophyll forest on the ridges.

In figure 3.1, each large blue dot represents an even amount of rainwater that has infiltrated into the land above our boundary. The dotted lines show the path that the water takes (90 degrees to contour) as it moves down through the soil profile. This image clearly illustrating why it is that the ridges are much drier than the valleys.

Figure 3.1 – Movement of soil moisture

Darren’s argument against swales in some instances

In figure 4.1 below, I’ve overlayed the swale infiltration path (figure 2.2) over the top of the rainfall infiltration (figure 3.1). As you’ll notice, the swale tends to direct far more water towards the valleys and hasn’t really fixed the issue of our dry ridgelines.

Figure 4.1 Swale infiltration (red) in relation to moisture entering site (light blue)

Recognising this issue, Darren prefers to set out tree lines using a keyline pattern. In this aerial shot of George Howson’s agroforestry property, ‘Dalpura’ (figure 4.2), the tree mounds aren’t on contour but rather they gently slope away from the valleys (the naturally moist areas) towards the ridges (the naturally dry areas), therefore aiming to even out the moisture levels across the landscape.

Figure 4.2 Dalpura tree lines from above

He creates his tree lines using a ripper and mounder, common in forestry plantings, which have a small gutter on the upper and lower sides which help to direct the water.  This is a cheaper and more fuel efficient option than a bulldozer or excavator, and works well in climates where rainfall events are generally consistent but small, such as in many temperate landscapes.

The green dots and arrows in figure 4.3 indicate the infiltration of the keyline mound during a small event. Water has been directed away from the valleys and encouraged to infiltrate on the ridge instead. You’ll notice that when combined with the water naturally moving down through the landscape from above, the moisture distribution is far more even than in the swale in figure 4.1

Figure 4.3 – Keyline mound infiltration (green) in a small rain event

Despite the obvious benefits, one downside I see to this approach is that the gutters on the sides of the tree mounds have a relatively small water holding capacity. If the landscape has dried out significantly, for instance during a long drought, it’s highly possible that the soils will become hydrophobic, and therefore there will be little water infiltrating as it travels along the gutters. During a large rain event, which occasionally come during the summer when moisture is most needed, due to the small capacity of the gutters, only a small amount of water will be held and given time to infiltrate. The rest will spill over the mound and down the ridge (figure 4.4). This would particularly be the case where there is a large catchment above as in the example used.

Figure 4.4 – Keyline mound overflow during a large rain event

(Note: At this point, I should mention that despite Darren’s mounds being smaller than Geoff’s swales, he places one for every line of trees, meaning that water infiltrates right at the base of each tree. Also, in the widescale forestry example of figure 4.2, the pasture in between the rows has been ripped using a keyline plow, which further increases the infiltration capacity. Similarly, when water does spill, it is in the best place possible – right up on the ridge where the water will fan out and have further opportunity to infiltrate)

The comparison in brief

Geoff’s swales – hold plenty of water in a large event but distribute the water less evenly in the landscape below

Darren’s keyline mounds – distributes soil water more evenly across the land, but holds and infiltrates less during a large event.

The keyline swale

With the benefits of each in mind, I came up with a hybrid, which you could call a keyline-swale.

It’s built just like a swale, set out on contour, except that the base of the swale isn’t level, rather it slopes from the valley out towards the ridges.

To build the keyline-swale, pegs are set out on contour. Starting at the ridge, a mark is made on each peg, rising at 1 in 500 towards the valleys. This is the guide for the blade depth (figure 5.1).

Figure 5.1 – Side section view of a bulldozer building a keyline swale

During a small rainfall event (figures 5.2 & 5.3), water is directed along the trench from the valleys to the ridges, where it infiltrates in a very similar pattern to Darren’s keyline mound.

Figure 5.2 Side section of a keyline swale during a small rain event

Figure 5.3 – Keyline swale (dark blue) infiltrating during a small rain event

During a large event, the water would fill up along the length like Geoff’s large swale, however the water depth wouldn’t be constant. One possible benefit of having a greater depth of water out on the ridges is that there will be more pressure here, causing water to infiltrate at a faster rate than it will in the valleys (figures 5.4 5.5). As the water level drops, it will of course infiltrate the remaining water on the ridge.

Figure 5.4 – Keyline swale full

Figure 5.5 – Keyline swale (dark blue) infiltrating during a large rain event

If this was a temperate climate where large rainfall events are rare, on this landscape I would go for a keyline swale at the very top of the property, and then use Darren’s keyline mounds parallel to this down the slope. This means you’ll get the benefits of water being infiltrated at the base of each of the tree rows (by the mounds), hydration of the ridgelines, while also capturing any large flows that enter the property, infiltrating them right at the top of the slope.

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Cam Wilson runs Forest Edge Permaculture Design, a Melbourne based consultancy offering permaculture Design, Education and Implementation. See the website for more details.