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Monthly Archives: October 2012

Peter Hazell showing the intact chain of ponds, on the property he is stewarding near Braidwood.

“One thing I noted was the striking difference in the primary productivity between the swampy meadows and the incised equivalent: it was chalk and cheese.” That’s Peter Hazell’s take on the first time he laid eyes on the property he and his wife Donna are now managing.

At the time, back in 2001, as a seasoned NRM scientist, Peter was conducting a land cover classification for the Landcare network. Using satellite imagery, different land cover types would show up as different patterns in the spectral analysis, and Peter would then head out into the field to ground truth it.

While doing so, there were areas in the upper catchment that were standing out as very vibrant so he thought he’d better take a look. It turned out that every place that was showing up as the richest land cover class in terms of primary production were the intact swampy meadows and chain of pond systems. In contrast, the drained, incised systems showed up as rather dull, with low production.

As well as stewarding one of the rare intact chain of pond systems that remains, Peter’s contribution to protecting and restoring these valuable environmental assets has included working closely with Peter Andrews while working as an NRM Facilitator with the Federal Department of Environment Water Heritage and the Arts, playing an instrumental role in getting the Natural Sequence Farming demonstration to happen at Mulloon Creek Natural Farms, involvement in the Upper Shoalhaven Natural Sequence Association, and potentially more research down the track.

Meanwhile, in 2003, Donna published what remains one of the only peer reviewed papers looking at the ecology of chain of pond systems, in particular the benefits of intact systems to frogs within an agricultural landscape. It’s a great paper and in my opinion remains one of the clearest overviews of the post-Euro settlement stream degradation process (you can access a copy here).

As a great example of the landscape hydration, leaky weirs, wetland habitat and natural erosion control we’re aiming to reinstate, I’ll share more about their property in future. This will include some interesting saline groundwater results, the way water pulses through the floodplain sediments, and some very simple small-scale erosion control which can be done, like Peter and Donna have, in your spare time with a couple of kids in tow.

When the results become public, I’ll also share more about the research which Nathan Weber has conducted on the Hazell’s property as part of his PhD on the effects of Natural Sequence Farming on upper catchment floodplain processes.

Article and Diagrams © Cam Wilson, Earth Integral, 2012

When erosion control work is carried out with floodplain rehydration in mind, a more sustained creek flow at the base of the property is one of the most common outcomes. Yet, of all the water harvesting and hydration concepts I’ve discussed with people, this remains the one which draws the most skepticism.

The following diagrams illustrate the way this process works:

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This is a fairly typical erosion gully in the Southern Tablelands. The major erosion happened decades ago, therefore the floor of the gully has mostly revegetated and stabilised. However, the alluvial aquifer remains drained down to approximately the base of the gully.

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With the gully incised, in many locations even the largest runoff events remain contained within the channel. For the short period the creek is running high, there is some lateral infiltration into the alluvial aquifer, but it’s often a fairly insignificant amount.

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Depending on the order of the stream, porous structures (or leaky weirs) of varying heights and types can be constructed (ie vegetated earth-banks, rock gabions, log sills, fascines, brush mattresses etc).

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Whenever there is sufficient flow from above, the structure causes a pool to form. As well as enabling riparian and wetland vegetation to establish with the associated bed stability and habitat benefits, the raised water level in the pool encourages water to laterally rehydrate the surrounding floodplain.

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When flood flows occur, depending on the height of the structure, access to the floodplain is now available once again. With the water spread in a thin sheet across the land, it not only reduces the energy and erosive potential within the channel, but also gives more opportunity for the alluvial aquifer to recharge, with infiltration from above.

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In time, depending largely on how porous the floodplain sediment is, the alluvial aquifer will be raised. (The closer to the surface the water table, the more important the flooding process becomes, due to the freshwater lens it creates over the heavier saline groundwater.)

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Due to porous nature of the structures and floodplain sediments, during extended periods without flow coming into the system, the pools can begin to drop. At such time, water stored in the floodplain begins to feed back into the creek, providing an extended base flow, potentially creating a perennial flow.

At the same time, depending on how high the water table has been raised, floodplain vegetation will benefit from moisture available through capillary action. Deep rooted perennial grasses and riparian trees such as Casuarina and Populus will benefit sooner of course, and provide construction material for further channel repair.

Disclaimer: Where water flow is concerned there are substantial risks involved. While the information and images we publish are formulated in good faith, with the intention of raising awareness of landscape rehydration processes, the contents do not take into account all the social, environmental and regulatory factors which need to be considered before putting that information into practice.  Accordingly, no person should rely on anything contained within as a substitute for specific professional advice.

Article and Images © Cam Wilson, Earth Integral, 2012

I don’t pretend in any way to have originated the concepts that I design and implement in the landscape, nor what I share on this blog. No one can really, as the intention is to emulate natural processes to the best of our understanding.

There are however a number of pioneers who can lay a bit more claim than most. Those pioneers I refer to are the ones who have stepped outside of the entrenched European farming paradigm and realised that the tried and tested patterns in Nature provide a solid template for design and practice. They’ve then pointed them out to the rest of us, and in doing so, have turned many of our paradigms upside down and put a fire in our belly for helping landscape rehabilitation to take place.

Peter Andrews (Source: Australian Story, ABC)

Peter Andrews is one of those pioneers. Since he shot to fame with the original Australian Story episode in 2005, he has arguably opened the eyes of more Australian mainstream farmers to the possibilities that natural processes present than anyone else. That episode, in which his efforts to restore a degraded system back to a rehydrated, functioning chain of ponds landscape, captured the imagination of both city and country folk alike, and proved to be the most popular episode ever.

In 2009 there was a follow up double episode called Right as Rain which can be viewed on the abc website (Click on the following links to see Part 1 and Part 2).

It wasn’t long after those episodes that I went to Mulloon Creek for the first time, along with a couple of hundred others for the open day of the Natural Sequence Farming demonstration. Pretty soon after that, that my family and I were living at Mulloon where I maintained the creek work for a couple of years. During that time, I’ve been lucky enough to spend a fair bit of time with Peter and whilst most of what he’s shared with me can be found in the pages of Back from the Brink and Beyond the Brink (essential reading of course), he has managed to put me on the spot plenty of times, testing and extending my thinking and understanding which I very much appreciate (although slightly challenging when it’s up on stage in front of 150 or so people).

The point of our blog and our business is that resting on the shoulders of giants (whose work we will be profiling and exposing on a regular basis) we hope to make these ideas even more accessible and achievable. We hope to remove the blocks that have prevented all but the most courageous pioneering types from undertaking this sort of work, helping to point out the pathway through the design and implementation process, as well as the wide room for movement within the current regulation framework (there is a common perception that everything Peter has suggested is illegal, but it just isn’t the case).

I see huge value from the position of landscape health in what Peter Andrews and other pioneers have shared and contributed. One of my hopes is to further clarify some of their ideas on this website through diagrams, writing and sharing case studies of those who have been inspired enough by his work to have a go on their land.

The purpose of our business is to help people to take that next step. Through our design, consultancy, implementation and education services we hope to place the tools in peoples hands for carrying out this incredibly important landscape rehabilitation work. For the health of the Aussie landscape, we hope you’ll be one of them.

We hope that on our journey we can make a contribution that is even a small portion of what Peter has done over the years in his tireless efforts of raising awareness about the processes in the Australian landscape.

On Jan 26th 2011 Peter Andrews was awarded Australia’s highest public award, the Order of Australia Medal. (Source: www.nsfarming.com)