Everyone is searching for an effective way to protect the Great Barrier Reef from alluvial gully sediment – TWQ Hub’s involvement in a cutting-edge gully remediation project might hold the answers
Erosion from alluvial gullies on rivers and creeks along the Queensland coast is a major point-source of fine sediment pollution to the Great Barrier Reef.
The ability to effectively reduce sediment output from these gullies is a major objective for Great Barrier Reef (GBR) water quality managers including the Queensland Government and the Reef Trust Partnership. Alluvial gullies are lost productive land and effective gully remediation is of great interest to land managers.
The Landholders Driving Change project is trialing a wide variety of gully remediation techniques at multiple sites across the Bowen, Broken and Bogie (BBB) catchment on the Queensland coast. A primary demonstration trial site at Mt Wickham is being used to test techniques including the installation of rock chutes, re-contouring, soil amelioration, chemical treatments and revegetation. Four hundred tonnes of topsoil has been removed and mixed with 70 tonnes of gypsum and over 370 tonnes of compost for re-application to the site, in addition to hay bales and seeds to add organic matter and slow water movement. Advanced elevation measuring technology such as aerial LiDAR scanners are being used to accurately guide these works, which has been carried out by local contractors, increasing economic activity in the region.
Multiple NESP TWQ Hub projects – including ‘Gully Remediation Effectiveness’ are conducting detailed monitoring on these trials using advanced water quality sampling equipment. Hub scientists are an integral part of the project, providing vital water quality monitoring to determine the ultimate effectiveness of each gully remediation approach.
Project lead Dr. Rebecca Bartley at CSIRO Land and Water said the data gathered by her team is informing stakeholders including the Queensland Government, the Reef Trust Partnership and the Great Barrier Reef Foundation, where it will be used to guide future investment in gully remediation efforts, including the Reef Trust’s Erosion Control Toolbox. Participating landholders can also use the data to guide practice change for ecological and economic reasons.
“I get a lot of calls particularly from the farmers who are always very keen to see the results – I’ve had plenty of interest in the existing reports,” Dr. Bartley said.
A field tour of monitoring sites as part of the recent International Gully Symposium in 2019 also brought stakeholders up to date on the project’s progress.
Photo: Rebecca Bartley