Tarwyn Park Training at Mulloon Creek
Mulloon Rehydration Initiative Project Coordinator Peter Hazell at Peter’s Pond.
Day two of Tarwyn Park Training natural sequence farming course, learning about contours, weirs, plants and landscape rehydration at the Mulloon Institute. Loving being amongst a beautiful crowd of people keen to repair our landscapes.
On days 3 and 4, we were out in the field, getting across contouring. We used laser levels to mark one out, and then met Glenn the excavator and watched his grader in action. We explored the subtleties of contour creation: the angle of the trench slope, the correct height of the downhill mound, how to avoid cutting too deep (don’t hit clay!) and where to locate the spillway (on the ridge!). We then walked a contour that had been created two years ago at another location of the Mulloon catchment, which gave us a great understanding of how they settle into the landscape.
“What we have here is a head cut.”
This is the site where erosion creeps further and further up a gully. When water flows at speed over the ‘toe’ of the head cut, it eats away at that spot and causes the surrounding earth to collapse… and so it continues. Stopping that creep is a tricky but necessary project to prevent erosion gullies from deepening and widening: one participant spoke of gullies at their property, “you could fit a double-decker bus in”. We discussed potential tactics for the head cut area: strategically placed rocks that cause the water to bounce between them and thus lose its erosive energy, and vegetation with strong root systems to stabilise the soil.
Laura Fisher, TMI Project Officer – Research
This workshop forms part of the Mulloon Rehydration Initiative which is jointly funded through the Mulloon Institute and the Australian Government’s National Landcare Program. The initiative is also assisted by the NSW Government through its Environmental Trust.