Eroded Gully to Flowing Ponds
Jillamatong was originally a leased block, and from the 1840s to 1950 the property suffered from short term management. By the 1980s a two-kilometre long series of active headcuts reached across the farm, with plenty of bare earth. The base ranged from one to four metres deep. Stock had continual access to the gully sides, which were in some places perpendicular cliffs.
The landscape impacts were not fully obvious at the time. Land drained quickly during rain, taking manure, soil and fertility with it. Salt was mobilised during sustained rain, generating readings of over 5000 ppm of sodium. The water the stock were accessing was of poor quality and contributed to health problems such as liver fluke.
Initially we installed earthen structures in the gully to try to stop the headwall cuts, and experimented with rocks and changing the angle of the stream to channel flows around problem areas, but that approach accelerated water movement off the farm rather than encouraging infiltration, conservation and efficient water use.
After I met Peter Andrews in 2005 I developed a new way of looking at the catchment, and realised that the original landscape had never had an incised creek line. So we constructed weirs to place the water back on the floodplain during high rainfall and built contour channels to rehydrate large areas of the property. Wetland plants, yabbies and fish have been added to most of the weirs and dams to assist in nutrient recycling and continue building biodiversity.
With the re-introduction of natural regeneration processes the gully has become a permanently flowing 'chain of ponds' waterway. The floodplain has been rehydrated and grass now grows well through drought conditions. Any fertiliser applied stays on the pastures and we never run out of clean water. The weir system has maintained a constant flow since 2007, even running when the nearby Shoalhaven River dried out in 2009.
Natural capital values have also increased significantly as a result of the increased rainfall retention, water harvesting, lower evaporation losses, capture of flood flows and prevention of soil and nutrient erosion. The benefits from such increased productive and resilient landscapes should become most marked as climate extremes intensify.
To find out how to do something like this legally and successfully, please come to one of our workshops at Tombarra. And for more detail on our overall water, stock, soil and vegetation management, please read the case study at Soils for Life.
Here are some more recent images of Jillamatong.