Innovative solutions to alluvial gully remediation: a case study from the Great Barrier Reef catchments (#78)
Improving water quality has a critical role in building the Reef's resilience to withstand the impacts of climate change. In May 2016, Greening Australia launched Reef Aid, an ambitious program to improve the health of the Great Barrier Reef by improving water quality through stabilising eroding gullies and restoring coastal wetlands. The current project focused on alluvial gullies, is an initiative funded by the Queensland Government and Greening Australia to identify more innovative and cost effective gully remediation techniques. The project is focused on reducing sediment in one of the highest sediment producing catchments, the Burdekin catchment. The Burdekin River catchment is estimated to deliver almost 50% of the total suspended sediment load to the Great Barrier Reef. Recent research indicates that the project site, Strathalbyn Station, alone has contributed approximately 300,000 tonnes of sediment to the reef from the 60 hectares of soil erosion sites that make up the Strathalbyn project area.
The current project is trialing different techniques to remediate gullies on at least 5 treatments sites (across 150 hectares). Phase 1 on-ground works program was completed on 13 December 2017. 1.5Ha of direct intervention was completed targeting sediment reduction of a treatment area of 8Ha. Control gully areas have also been identified which will be used for comparison. An extensive monitoring program has been initiated on site including multiple automated sediment sampling stations in the treated catchment, the control gully, and in gullies which are targeted for works but where works have not yet occurred (ie. baseline data collection). Preliminary results suggest significant differences in sediment between treated and control sites. Additional rain events and samples will enable these results to be further quantified. Phase 2 works commence in May 2018, and these treatments as well the preliminary results from Phase 1 will be discussed.