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Below are some photos and videos taken along a transect of the floodplain on Peter and Kate Marshall’s property. I hope you enjoy these images (taken 36 hrs after a 180mm overnight event), with the creek running crystal clear and spread out across the floodplain on Sunningdale.

To put what you’re seeing in context, most other watercourses in the region are restricted predominantly to the channel due to the erosion and incision caused by past land management practices. Although man-made, the hydrology in this landscape is much closer to the way it operated pre Euro settlement, in an intact chain of ponds or swampy meadow system. The noise of the frogs in the videos is testament to the significant aquatic and wetland habitat which has also been created.

Photo locations taken across a transect of the floodplain at Sunningdale

Locations of photos taken across a transect of the floodplain at Sunningdale. (For some scale, the image is 350m wide, and the main channel located at the meandering tree-line, flowing from bottom to top).

To flick through a larger slideshow of the images, click on any of the thumbnails below

Short video locations taken across a transect of the floodplain at Sunningdale

Locations of short videos taken across a transect of the floodplain at Sunningdale

Finally, another interesting little clip is of the ground literally bubbling as the subsurface flow rehydrates the gravel and sediments below the surface. This stored moisture benefits the land’s production and drought proofing resilience, while also providing a more sustained base-flow to the landscape below.

See the articles tagged as Key floodplain processes for more information on what is being achieved from a landscape perspective.

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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, 2013

A stroll, post flood

A stroll, post flood

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Increasing atmospheric CO2 levels during the industrial age have gained a lot of exposure in the link with a changing climate. An area which has received far less attention are the significant changes to both local and global water cycles and vegetation patterns during the same period of time.

Water For the Recovery of the Climate – A New Water Paradigm (Kravcik et al, 2007) explores the science behind the very direct links between vegetation and both temperature and precipitation.

It’s a read I highly recommend and it can be downloaded by clicking on the title in the paragraph above. So that the time-poor can get the gist, I have included a number of the diagrams from the paper in a slideshow at the bottom of this article.

Here’s a very simple summary as well:

1) At any given time or place on the planet, there’s a certain amount of solar energy hitting the surface of the earth. That energy can be put to two very different uses.

The distribution of solar energy on drained land and on a landscape saturated with water (Kravcik et al, 2007)

At one extreme, a bare soil (or concrete, steel, etc), the majority of that energy is absorbed and re-radiated as (sensible) heat, warming the local environment.

At the other extreme, a saturated wetland, the majority of that energy is utilised by plants for photosynthesis, with the resulting transpiration drawing (latent) heat from the surrounding area.

So the sun’s energy is used to either power a landscape-scale radiant heater (above left) or a landscape-scale evaporative air conditioner (above right).

2) Of the average 720mm of precipitation that falls on land, the input from the sea is about 310 mm (the large water cycle). Hence, the land provides the larger part of its own precipitation (410 mm) from its own land-based evaporation (the small water cycle).

Small water cycle

Kravcik et al (2007)

Therefore, a drained and dehydrated landscape, coinciding with relatively shallow rooted plants (ie conventional western agriculture) ultimately means less rain over the land, in a (not so) positive feedback loop.

A landscape which is primed to accept whatever rainfall or overland flow that arrives and to send that moisture through actively growing plants, means more rain over the land in a (more) positive feedback loop.

More soil moisture = more evapotranspiration = more precipitation = more soil moisture etc

The radiant heater mentioned previously means less rain; the evaporative air conditioner, more.

In closing, a couple of short paragraphs from the paper:

“The renewal of the domination of the small water cycle, which is advantageous for humanity, vegetation and the land, depends on the renewal of the functional plant cover of a territory and water surfaces in a country.”

“With sensible management of water and vegetation we can curb climatic change on the local level; if we can act in the same way across larger areas, perhaps we can expect a tempering of global climate change.”

We’re in the business of landscape-scale air conditioners, so if you’re interested, please get in touch. Or, visit and ‘Like’ our Facebook page to hear about future posts.

 

Reference:

Kravcik M., Pokorny J., Kohutiar J., Kovac M., Toth, E, 2007. Water For the Recovery of the Climate – A New Water Paradigm

Click here to download a pdf of the paper

Click on the images for a slideshow of the diagrams from the paper.

It’s hard to encapsulate all that is happening on Peter and Kate Marshall’s property Sunningdale in one go, but the following series of photos will give you a bit of a taste.

Peter is a pretty special guy. He’s got an understanding of the wider landscape processes which equals Peter Andrews, but he’s also a trained forester and is as widely read and knowledgable as anyone I have met. Add that combination to a desire to fix up some of the considerable degradation caused by his family in past generations and his wife Kate who is equally passionate and equally keen to heal their landscape and you have a pretty powerful combination.

Since commencing their work 22 years ago, the Marshall’s haven’t had it easy. Despite recognition from some of the top mycologists, hydrologists and foresters from here and abroad, within their own community they were largely ostracised early on, from members of the farming community on the one hand because they were seen as the thin edge of a green wedge, and from members of Landcare network on the other because they were using exotic species which Peter knew to have more potential in some land repair roles. Electric fences were cut, waterways were poisoned, authorities were called resulting in the threat of large fines, their children were bullied on the school bus and nuts were even taken off tractor wheels.

An amazing sign of the times is that on Friday night, the Marshall’s received a Champions of the Catchment award from the Upper Shoalhaven Landcare network. This award was introduced to recognise those who have done outstanding work in land repair which differs from the standard few lines of Eucalypts which usually fit the award criteria.

The next day, a tour of their place was conducted. “This is uplifting” was the way that one participant summed it up. Here’s a glance at a small portion of the uplifting work they they have carried out.

Peter leads off the tour, past the considerable biomass produced by Salix and Populus species after only 11 years of growth. These trees moderate the climate significantly through wind protection and transpiration effects.

Here, Salix plantings replicate the gallery forests which existed at the time of European settlement. Exotic species have been chosen due to the changed conditions making the original dominant species, Casuarina, very difficult to establish (heavier more acidic sediment, hare and rabbit predation, reduced frost protection due to complete deforestation and a dehydrated landscape).

Higher on the slope, Casuarinas have been easier to establish. Here, the ones in the background are being pruned for valuable furniture timber as are a wide range of other farm forestry species, suited to different sites on the property

Pinus radiata are pruned up for better quality timber. They were originally established due to their recognition by the tax man, but the focus has changed over time with the most valuable crop now below the ground, in the form of edible mushrooms such as slippery jack and saffron milk cap.

Here the group observes the understorey of ferns which has established beneath Blackwood and local tea tree. This site was dense with blackberries only 12 years without a tree in site. Seed filled brush mattresses of Leptospermum and mud encapsulated seed balls of Acacia were the main reveg techniques used.

Due to the repair of the main creek, the floodplain has rehydrated. These flats have been excavated to tap into the groundwater, creating a mosaic of water and earth, rich in biodiversity in some places…….

……..and planted out to useful agricultural crops in other places such as cricket bat timber or it would be perfect for ducks, fruit and veg if someone wishes to start an enterprise.

Fodder trees are grown in the hydrated landscape, the leaves and bark of which are devoured by goats and sheep. The left over woody biomass can either become material for building erosion-repairing fascines, or innoculated with saprophytic edible mushrooms like shitake.

A number of methods are used for establishing pole plantings while stock are in the paddock such as these tech-screwed tyres.

Wire mesh can also be used to protect trees from ringbarking

One of the Marshall’s most valuable and successful crops is the black truffle. This is a new orchard which has been established this season, using locally adapted oaks with excellent form for light penetration, and innoculated from a portion of their own truffle stock which they put aside this season.

These oaks were a pleasure to plant into the well prepared bed. This site was like concrete when Peter and Kate first purchased it, but after successive rips with the Keyline plough and a series of green manures, you couldn’t ask for a better start to life if you were a tap-rooted tree.

A number of stands of monopodial bamboos have been established for a variety of uses across the property including soil stabilisation, building material, fodder, biochar production and garden stakes which is an enterprise their daughter Rita runs.

What was once a bare walled gully is now a stabilised chain of ponds

This large world class wetland was created on another one of the hydrated flats, which now has black swans nesting. This particular piece of extensive work seems very altruistic, which it is based on the desire to reverse some of the degradation caused by each of Peter and Kate’s families over the generations, but this area of beautiful wetland habitat also offers significant hydration benefits to the surrounding landscape, with groundwater essentially backing up the slopes.

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Article and images Copyright Cam Wilson, Earth Integral, 2012

There are many different ways that Peter and Kate Marshall have turned degraded sites around on ‘Sunningdale’, setting landscape rehydration and repair processes into action.

One of the methods was this series of vegetated earth banks, which are situated in a second order gully, higher in the catchment. The photos tell the story.

Fabric protecting the 8 newly constructed earth banks in 2004. Sedges were pinned on top of the material, the rhizomes binding the banks together

In 2012, the vegetation is well established and the banks have remained stable, in a fashion very similar to those in an intact chain of ponds. The ponds are beginning to shrink as the sedge and rush marches into the water, providing valuable wetland habitat as they do

Here, sediment and algae is caught by the sedge covered banks during a small flow event, providing material and nutrients to assist with further vertical growth of the banks

In this photo, the shovel has cut down to the fabric which remains below the surface, showing the material which has built up. Sediment caught and trapped by the tussocks, rhizomes and root mats of the sedge, as well as their bulk organic material, help the banks to grow in height

As a result of these simple earthworks, the ponds and wetland plants themselves provide valuable wetland habitat, whilst also improving the drought resilience of the landscape through the lateral hydration of the surrounding floodplain In time, as the banks continue to aggrade, this will provide further benefits by returning flood flows to the floodplain surface.

If anyone is interested in spending some time working on the Marshall’s property, feel free to contact us and we can put you in touch.

Or, if you’re interested in getting these processes happening once again on your land, contact us to find out about our design, consultancy and implementation services.

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

When building natural capital (including beef or wool), increased potosynthesis is the goal of any land manager. Available moisture is, of course, a key factor.

At the time Europeans settled in South-Eastern Australia, many broad upland valleys were described as chains of ponds or swampy meadows. There are a few of these well hydrated, very productive systems, effectively drought proof systems still remaining (for example the Hazell’s property), but the majority have been severely eroded and subsequently drained (click on the following for an outline of the degradation process, in diagrams or the scientific literature).

At Tarwyn Park, Peter Andrews demonstrated the potential primary production benefits from reinstating the original floodplain processes and rehydrating the surrounding landscape.

One way of doing so is by raising the alluvial water table through lateral infiltration (as described in the post Floodplain water storage). The speed this occurs depends on the soil type, but if it’s going to happen any time soon the main driving factor is a fairly constant supply of water from the catchment above.

High in the landscape, inflow from the catchment above is generally only available for a short period of time. Where this is the case, the effectiveness of relying solely on a lateral hydration approach is limited, as a severely drained landscape will take a considerable time (maybe several lifetimes) before the water table is raised high enough to enhance plant growth on the floodplain.

Where short sharp bursts of runoff are available, the fastest return can be achieved by reinstating the old flood flows. Water spreads out across the landscape once more, soaking into the floodplain for the extended use by the plants and soil life. Sediments are also deposited, the process which has made floodplains the rich production zones they are worldwide. Basically, it’s recommissioning nature’s flood fertigation system.

In an intact landscape, there are predictable locations where floodwater is more likely to top the banks, just as there are locations where it’s likely to re-enter:

On a macro-scale, floodplain flow patterns are often closely related to the ridges intruding into the floodplain (Tane, 1999)

Where multiple ponds exist between the major landscape features, braided flood flows (red arrows) generally exit the downstream half and enter the upstream half of a pond (P Hazell, personal conversation)

When siting structures, an understanding of these processes is the key to getting the most bang for your buck. A structure in an inappropriate location may get the water up onto the floodplain, but it will soon spill back into the gully, maybe even worsening the existing erosion. In contrast, a well positioned structure results in the flow heading away from the watercourse, spreading into a more passive flow and hydrating the floodplain surface before re-entering the stream sometimes hundreds of metres downstream.

On Gunningrah, Charlie and Anne Maslin have sited their structures as well as anyone I’ve seen with this goal in mind. Having taken inspiration from Peter Andrews on ‘Australian Story’ and attending a Natural Sequence Farming field day, Charlie has since constructed around 40 leaky weirs on Gunningrah (For more information about the Maslin’s farming prowess, see their profile in the Soils for life case studies).

There are a range of positive results which the Maslins have achieved depending on the landscape position of the works, but the following couple of examples are a good demonstration of utilising the original flooding processes mentioned above.

(Note: To avoid hefty fines, it’s important to adhere to local watercourse regulations. In many places there are few restrictions on ‘dam walls’ within first and second order streams other than the harvestable rights of the property)

Poplar site

Flow had become contained within the incised channel, taking shortest path it could towards the ocean. The only moisture available to the surrounding floodplain was what fell from the sky

An earth wall structure intercepts the flow in the channel, reconnecting it with the floodplain. The flow re-enters more than 500m downstream, with the potential to irrigate about 6 ha of pasture.

The poplars indicate the path of the incised channel, the flow now spreads out across the floodplain

Looking upstream at the same structure, the flow spreads significantly across the paddock.

Debris in the middle of the paddock, around 50m from the main channel.

Hayshed site

Flow path before the works….

….. and afterwards, back to how it once was

An aerial view of the flow before the works were completed, contained within the incised channel

An earth wall intercepts the channelised flow, spilling onto the surrounding floodplain. For an idea of the extra water harvesting potential which results, 0.25 Megalitre is stored for every 25mm of water that’s accepted by the landscape per hectare. A healthy topsoil can receive far more than that.

In case you’re still wondering “How can water flow away from the main watercourse? Isn’t that always the lowest point?” It is in a young landscape, but Australia’s pretty geriatric as far as watersheds go.

In Back from the brink, Peter Andrews talks about water flowing on the high ground (of the floodplain). This phenomena was observed by plenty of early explorers and it’s also well accepted in the scientific literature. In short, when a watercourse spills its banks, the water slows down, depositing the heaviest sediment. In time, a natural levee is built as seen below.

If you’re interested in getting these processes happening once again on your land, contact us to find out about our design, consultancy and implementation services.

Please visit and ‘Like’ our Facebook page to hear about future posts.

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

References

Tane, H. 1999. Catchment Habitats and Landscape Ecosystems. Centre for Catchment Ecology, 1: 1-12

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

This is a pictorial tour of the degradation and dehydration process that the Australian landscape went through post European settlement, along with one of the major aims of Peter Andrews’ Natural Sequence Farming approach, namely the rehydration of the Australian landscape.

If you were one of the early explorers, walking into a wide floodplain system in the early 1800s, more than likely you would have found some form of discontinuous watercourse. One example is known as a ‘chain of ponds’, in which you’d find small bodies of open water, about a metre below the level of the floodplain, held in place and separated from the next pond by a marshy plug of reeds such as Phragmites.

These ponds weren’t the whole story though. They were just the tip of the iceberg and indicated the level of the water table under the rest of the floodplain-step. That is, moisture within a metre or so of the toes of all of the plants on the floodplain.

When a decent flow occurred, rather than it rushing downstream, the reed beds would slow the water causing it to gently rise and flow over the banks onto the floodplain. This gave the water plenty of chance to infiltrate and recharge the aquifer below (a wise move for a landscape to make when the next generous rain might be a few months away). You might also notice something strange; the banks of the creek are higher than the rest of the floodplain. This is because when the water spills over the banks, the largest sediment settles out first, building up a levee over time.

With the landscape scouted, settlers soon arrived with their animals, ring barking as they went. There weren’t many stock troughs in those days, so of course the animals had to drink from the creeks.

The hard hooves soon cut tracks into the reeds and were one of the ways the marshy plugs were killed off.

With the plugs gone, coupled with the cleared, burnt and overgrazed hillside up above the floodplain, water could now build some momentum, and soon scoured out the deep erosion gullies we still see today.

With the ponds no longer in place, the gully turned into a really efficient drain….

… lowering the alluvial aquifer….

… down to the base of the incised channel. Once this occurred, rather than plants having moisture 1m below, they’re high and dry and at the mercy of the infrequent rainfall patterns experienced in much of the Australian landscape.

Once a channel is deeply incised, in many places even a large rainfall event is confined to the channel. This deprives the floodplain of the soaking sheets of water and fertile sediment of yesteryear.

Peter’s approach is about replicating the job that wetlands used to do. He creates ‘leaky weirs’ using locally available materials. Vegetation is an important component of the leaky weirs, with the fibrous root system of bioengineering plants such as willow used to tie the boulders together. This approach results in structures that are a fraction of the cost of the highly engineered structures commonly built by authorities. Peter also believes that the exclusion of livestock is important, except for periodic crash grazing.

The weirs enable chains of ponds to re-form, which begin to raise the alluvial aquifer (particularly through buried old creek lines which act as gravelly intake areas along the banks).

The rehydration will obviously happen faster in sandy soils than it will in heavy clay, but slowly the aim is for the alluvial aquifer to be raised. This is water harvesting in the form of reinstating a natural landscape process.

Eventually, the goal is to reinstate a drought-proof landscape.

At such time, flood processes become important once again, by creating a freshwater lens on top of the heavier, saline groundwater

If you’re interested in implementing strategies similar to these on your property, please contact us

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 Diagrams © Cam Wilson, Earth Integral 2012