Not too long ago, two of our most internationally renowned permaculture teachers/consultants had some vigorous disagreement on social media. Hordes of commenters weighed in on either or neither side. The explicit topic of the disagreement was the value of contour ditches – known in permaculture as ‘swales’ – for managing water in the landscape. Are they (A) a universal solution for every landscape? Or are they (B) barely worth considering, and then only in a few limited contexts? It’s worth reading, if you’re into that kind of thing. (If you’re on FB, you should be able to find the thread here.) In brief, Geoff Lawton occupies the position A: swales pretty much everywhere. Darren Doherty takes position B: swales rarely or never, because off-contour ripping (aka Keyline) and woody perennials make swales superfluous at best.

For what it’s worth, I’m delighted to see this discussion emerge in public. Let 100 flowers bloom, let 100 schools of thought contend, etc. Full disclosure, though: I have a lot of respect for the work of both of these men, but I tend to be put off by Lawton’s style, which I find too evangelical and too dogmatic about technique. Doherty turns up the methodical design process and turns down the evangelism to a level I can handle. Of course, like Lawton, Doherty is trying to support his family and change the world – both of which demand some level of charisma and showmanship. I don’t fault either for that.

In the FB discussion about contour ditches, I was struck most by what wasn’t discussed. The unspoken limits of the discussion highlighted how much permaculture has to learn from agroecology – in particular, how to learn like agroecology. This debate over water harvesting serves as a window onto issues that run through the whole of permaculture.

Stay with me for a minute. From what I could see (note: I didn’t comb through every single comment in the thread), all the arguments in that discussion relied on two sources of credibility: personal experience and/or the authority of one’s teacher. I find the former much more useful than the latter, but they both have some severe limitations. I did appreciate seeing comments acknowledging the absence of and the need for experimental trials of different systems. But as those commenters noted, research is expensive and time-consuming, and it’s difficult to attract research money and (thus) researchers. So while we work toward a people’s science – which I hope we are doing – we can only evaluate claims with the tools we got now. Which are, it would appear, personal experience and received wisdom.

Hold on, though.

What about learning from traditional land users and traditional land management systems?

It’s self-evident that all traditional cultures, past and present, developed systems for managing water in the landscape in some fashion. Most, if not all, did this by modifying the topography: on- and off-contour, from patch- to landscape scale. And most, if not all, did it using strategies that evolved through long-term cycles of experimentation and feedback grounded in people and place.

These techniques – outcomes of millenia of invention and experimentation – represent a massive global library of practice. More and more of that library is documented and synthesized (and available on the web). We should expect that every practice in that library is ingenious, and not one of them is perfect. As with traditional ecological knowledge generally, we can expect staggering commonalities in pattern across biomes, and wide, wild variation in detail – sometimes from one watershed to the next! This library should be one of the foundations of our debate and experimentation vis-à-vis water harvesting. Especially in the absence of our own rigorous documented trials, the global library is one of the very first resources we should be turning to for debates about practice. Otherwise we are left – at best – with our default mode of extrapolating wildly from anecdotal evidence across dissimilar contexts. And at worst, we’re stuck with this – ahem – fucking absurd choice over which white Australian dude figured it all out in mid- to late-20th century.

Between P.A.Yeoman, Bill Mollison, and David Holmgren (originator of Keyline planning, and co-originators of permaculture, respectively) I know that Mollison at least claimed some direct influence by indigenous land management. But for those who would claim that Mollison already reviewed and synthesized that global library for us (and that we can therefore simply rely on what he taught and wrote), I say to you: Dude. Please.

There is a wealth of information on the web about water harvesting techniques from all over the world – but if we google “swales” we’ll only find the same stuff handed down from Mollison. As far as I can tell he’s the only one who ever used that term to refer to dead-level contour ditches. In fact, throughout civil and environmental engineering literature, ‘swale’ refers to an off-contour drainage ditch. Neither is the term used anywhere outside of permaculture in connection with water-harvesting systems for agriculture. Over the (too many) hours I’ve spent searching for the precedents and parallels of permaculture practices (!), these are some of the key words that have actually been helpful:

ridge and furrow

bunds and contour bunds

micro-catchment

contour ditches or trenches

water-harvesting agriculture

runoff farming / runoff agriculture

There is a vibrant literature on these issues that you’ll never encounter if you only know the permaculture terminology of swales and earthworks. I’m far from the first to notice this. For the past few decades Brad Lancaster has built his life and career around reinventing and revitalizing the permaculture framework on water harvesting. His work is grounded in every way I could hope for: through years of personal experience and experimentation, direct contact with elders and traditional practice near and far, and familiarity with the extensive international literature on water harvesting. I’m happy to see the influence of his work growing! At the same time, we continue to see Mollison’s take on swales treated as canon to be faithfully preserved and transmitted, rather than part of a living, growing body of practice.

At the risk of derailing entirely, I’m going to indulge a fascination of mine and (hopefully) illustrate a point along the way. I’ve long been curious as to how Mollison got fixated on dead-level contour ditches, and why he adopted the curious terminology he did. In 1979, Mollison totally disses contour ditches in Permaculture Two. Just two years later in 1981 he raves about them – as swales – at the first permaculture design course in the US. What the hell happened?

Here is everything Mollison has to say in 1979 about what he would later come to call swales:

“What we tend to see [instead of effective techniques like perennials on contour and chisel plowing] are fairly massive contour trenches, allowing little soil absorption of water, creating dry strips on slopes, and exposing a great deal of subsoil; such heavy- handed approaches need massive machinery, and achieve little in the way of water control and soil improvement, compared with planned chiselling and planting, which makes a permanent and stable change on hillsides.” (Permaculture Two, p. 63)

By the time of the 1981 PDC, he is going big on swales. Here is a sample from among many comments:

“You cut shallow blade trenches on true contours, with no movement of water along the trenches. The trenches are quite broad, hardly ever less than four feet wide, and often much wider. You wouldn’t do this on a steep slope, just a moderate to shallow slope system. […] The water finds your widened areas, which are free, and soaks in, and thus charges your ground water instead of going down the hill and off the property. In three or four years, you will have 17 to 20 feet of fully charged soil. Your forest, just above your swale, is alive and has access to this water. Your forest will be alive when your neighbor’s ground water has flowed away out of sight.” (Transcript here, p. 15),

Somewhere on the road to Damascus Wilton, New Hampshire, the scales fell from his eyes.

He may have had his revelation (as so many do) in California. In that 1981 PDC Mollison speaks very admiringly of the naturalistic swales used in the stormwater management system at the famous Village Homes development in Davis, CA. He summarizes here:

“This system exists nowhere that I know of except in the village project at Davis, California. Here they sit on a plain near Sacramento, and because of swales the place is an oasis in a desert of disaster.” (ibid.)

Evidence suggests that Mollison learned the term swale on his visit to Village Homes, around 1980, from the very man who designed the development – Michael Corbett. Mollison as much as tells us so – by accident – ten years later. In 1991, on the Urban Permaculture episode of his Global Gardener series, Mollison takes us on a tour through Village Homes. During this tour, Mollison credits Corbett for reviving the word swale from Old English. It’s easy for us now, with the web at our fingertips, to disprove this rather fanciful idea: the word was used throughout the 20th century to describe wet, generally linear, depressions in the landscape. But more importantly, at the time of Corbett’s work on Village Homes, the term was in regular use in the civil engineering disciplines, in just the way it is now: referring to a drainage channel. This makes some logical sense of course: Corbett had to wage a lengthy struggle to get official approval for his forward-thinking design. He may not have succeeded in that struggle if he insisted on using obscure Old English terminology to explain his ideas.

But whatever Mollison’s ideas about the origins of the term, it’s clear from his statement that he first heard it from Corbett. The tragicomedy of this connection is that the swales of Village Homes were not on contour. Like most engineered swales, their slope was shallow enough to perform infiltration functions, but steep enough to perform the functions of drainage and diversion. In this way, Corbett was using ‘swale’ in the conventional and accepted sense. Many references to swales in Corbett’s Designing Sustainable Communities make that clear that they were flowing – not static. Here’s one example:

“[Our storm runoff] finds it’s way into attractive, meandering, creeklike shallow swales that run through the common areas behind the houses. These swales carry the water slowly to larger channels that run through the greenbelts. […] Small dams in the channels, just sturdy pieces of wood, help to slow the flow of water and prevent surges downstream.” (p. 44)



So between 1979 and 1981, Mollison learned the term swale from Corbett, and either misunderstood their basic design or decided to spontaneously appropriate and re-direct the term to describe a related but categorically distinct technique. Let’s be clear: Mollison’s body of work is full of genius and inspiration, and his contributions are truly mammoth. But he’s neither a prophet nor infallible. Permaculture didn’t spring fully-formed from his (or Holmgren’s) forehead like Athena from the head of Zeus. More to the point, permaculture didn’t emerge from a thorough review of global best practices – how could it? How would that even be possible for an institution-phobic iconoclast like Mollison? Stating these facts isn’t actually a criticism of permaculture itself – and only a rather gentle criticism of Mollison’s very human braggadocio and sometimes-slipshod scholarship. It’s a criticism of how we use and develop permaculture.

To his credit, it’s clear that Mollison himself has continued to investigate the fine details of arid land water-harvesting, and to learn from dedicated researchers in long-term research projects – as shown here – who are in turn studying traditional land management. But the permaculture movement remains saddled with a tendency to view the writings of our founders as complete and infallible, and retains a dangerous weakness for fetishizing particular techniques as universal solutions. We often seem committed to an arbitrary and idiosyncratic terminology that isolates us from our natural allies and teachers around the world (don’t even get me started on ‘guilds’). And we are prone to severely undervaluing – in practice if not in lip-service – the depth and breadth of traditional ecological knowledge, and by extension overvaluing the comparatively puny and partial synthesis we have assembled.

So we come to one of the great strengths of agroecology – and one of the things I think we should try and learn from it. Agroecology, as a discipline and a movement, was founded with the explicit aim of understanding and defending traditional and indigenous agriculture, even as we offer resources to support improvement and grounded innovation. As permaculturists think critically about where our ideas come from, we need to also think about where we want to take them. For those of us working in international development, the belief that our toolbox already contains all the best of best practices will render us incapable of the protracted and respectful observation and learning that makes the difference between grounded success and evangelical failure.

There is no shortage of innovation needed, as permaculture makes more inroads into broad-scale production. As we innovate, we would be well served to return again and again to that global library – whether we encounter it transcribed in books or embodied in communities. We need to exercise our humility alongside our critical curiosity, and learn from the incredible diversity and commonality of traditional land management strategies, experimenting and adapting over millennia.

Selected Resources:

FAO Water Harvesting Online Catalog

WOCAT publications – all highly recommended