Rock chutes put through their paces on cattle stations on the Atherton Tablelands have been given the thumbs-up as solutions to gully erosion and topsoil losses.
The first La Nina wet season sent floodwaters down chutes and through other rock structures that were built over the last three years on properties in the Mt Garnet and Innot Hot Springs area, and monitoring work was recently completed.
Terrain NRM project manager Jen Mackenzie said rainfall over the past five months had given the engineered structures a solid testing period.
Four rock chutes have been constructed on cattle stations, along with bund walls, and different rock structures were installed at tailings dams from historical mining ventures on cattle properties.
The annual monitoring also includes inspections of native grasses, planted at these sites as part of the projects.
"It's all about improving the land for graziers, as well as the quality of water flowing through the Herbert catchment and out to the Great Barrier Reef lagoon,'' Ms Mackenzie said.
Together, the four rock chutes will each year prevent an estimated 1200 tonnes of sediment - the equivalent to 50 semi-trailer loads - from reaching the Great Barrier Reef.
Chutes range from 20 metres to 100 metres long.
"Rock chutes are robust engineering structures that dissipate the energy from large water flows and prevent erosion from continuing upstream,'' Ms Mackenzie said. "They are part of a solution that also includes fencing to manage erosion and cattle movements, the installation of off-stream watering points, and changes to grazing management practices."
The work is part of the $3 million Herbert Gully and Grazing Project, delivered by Terrain NRM and funded through the Australian Government's Reef Trust IV program. Through the project, hundreds of graziers have been going to workshops on natural grazing methods targeting stock rotation patterns, soil health and pasture management.
Read more: Erosion project improves Tablelands pastures
