From ‘concrete’ to ‘sponge’: slowing the flow on Aussie farmland
October 2020, a section of Mulloon Creek at Palerang, NSW where a series of shallow v-shaped weirs have helped slow and retain water through the soil and surrounding landscapes.
The Guardian, 19 October 2022
Despite record-breaking rainfall and floods this year, eastern Australian landscapes are facing hydration issues. Slowing the flow of water on farms can help.
There’s a lot of farmland in Australia: about 427m hectares, making up 55% of the nation’s land use. Its condition affects our lives in the most primal ways, from the water we drink, to our ability to cope with flood, fire and drought.
Professor Stephen Dovers, chair of the science advisory committee at the Mulloon Institute, an organisation that develops and shares regenerative farming techniques, believes the state of farmland depends heavily on one issue: how well the land holds onto water.
“Rain is an income,” Dovers says. And too often, rather than banking that resource, we leave it to “flow out the drain”.
The same section of Mulloon Creek shown in main image, three months earlier in August 2020 following a rain event.
The country’s poor water management is illustrated by the fact that despite record-breaking rainfall this year and floods across eastern Australia, landscapes are facing hydration issues.
What good hydration looks like
“We should not see water disappear quickly off paddocks, off fields, down eroded gullies and streams,” Dovers says. “We want to retain water in the landscape, and that’s the fundamental aim of rehydration and a lot of other regenerative farming, even traditional farming: to try and capture as much of that water.”
Through construction and replanting, the institute, based at Bungendore in the New South Wales Southern Tablelands, creates obstacle courses for the water, causing the land to retain it, which creates reserves, and benefits biodiversity. Rather than leaving the land in a quick and wasteful run-off, water is captured and stored in the soil, and flows into our streams slowly, ensuring more water in soil and streams during dry spells.
The way in which water travels under and along the ground is key, Dovers says.
To illustrate, he calls up the image of a backyard: “If I concrete it, all the water runs off. If I have a native garden with mulch, the water soaks in.” The aim is: “A porous landscape, which basically works like a sponge, or a kind of underground dam.”
A v-shaped weir constructed on Mulloon Creek at Palerang, NSW.
Peter Hazell, principal landscape planner at the institute, says farming practices dating back to the arrival of Europeans have changed much of Australia’s land to the extent that it can no longer retain water.
“It’s like our landscape has dysentery,” he says. “It doesn’t matter how much water you drink, it’s still just going to go straight through you.”
Why hydration matters
The institute’s rehydration work is designed to help farmland cope with climatic extremes. “We are looking at a drier climate, but with more extremes of drought and heavy rain events,” Hazell says.
“The drier catchments are, the less resilient they are to the growing extremes in climate that we’re having. You rebuild the function of the catchment, then it has so much more ability to buffer extremes of drought, and floods and fires.”
Fire is a key consideration, particularly in the wake of the record 2019-20 bushfires, in which an estimated 17m hectares of Australian land were burned, according to AFAC, the national council for fire and emergency services. Hazell says well-hydrated land with greener vegetation is not only more resistant to burning, but can act as a firebreak. He says his own property became “the last stand” during that season’s mega fire that swept through Currowan and the south coast of New South Wales. Thanks to the intact chain of ponds on his and his wife’s land, they were able to pump more water to continue fighting the fire.
Hydration in wet weather is also critical. “You want to hang on to a bit of that water because once it goes dry again, you’re going to need it,” Hazell says. “And this is why droughts are biting so hard.
Another section of Mulloon Creek on Mulloon Creek Natural Farms, supporting habitat biodiversity and hydration of surrounding soils.
“Water will always run off the ground, but without intervention and management that slows that flow, that’s where you lose water quickly.”
Erosion caused by fast-flowing water results in the loss of soil, depleting nutrients on the farm. Once that eroded soil migrates beyond the farm, it becomes a whole new problem. Hazell cites the contamination of drinking water in Sydney in 1998, and recently in Dubbo. Further north, sediment from farms upsets the ecology of the Great Barrier Reef – another issue that the institute is using its research to help solve.
By being hospitable to life, and accumulating organic matter, hydrated soil sequesters carbon from the atmosphere. This mitigates the global heating effects of atmospheric carbon dioxide. When land cannot hold onto water, the effect is the opposite.
Beyond Mulloon Creek
The institute’s pilot project, the Mulloon Rehydration Initiative, which began as a collaborative effort in 2005, involves 23 neighbouring landholders. Now, farmers around Australia are turning to the institute’s experts for advice, so they can rehydrate their land as well.
As a not-for-profit, the institute’s work relies on external support. And support is growing. A recent pledge of $1.25m by plant-based food and beverage company Vitasoy is the largest corporate pledge yet for the institute.
It will help fund essential work, says the institute’s CEO and managing director, Carolyn Hall. “Financial support from groups like Vitasoy means we can help build a brighter future for Australian farmers, by equipping them with landscape rehydration skills and helping them build greater resilience in the landscape,” she says.
* The Mulloon Rehydration Initiative is jointly funded through the Mulloon Institute and the Australian Government’s National Landcare Program, with assistance from the NSW Government’s Environmental Trust.