These estimates have been calculated using two methods:
1) The pollutant reduction component of the Alluvium/Great Barrier Reef Foundation (GBRF) investment tool for hillslope and streambank erosion management projects;
2) The Reef Trust Gully Toolbox method for gully erosion management projects. The LDC Water Quality Report 2020 (Waterhouse et al., 2020) highlights that a number of assumptions underlay these calculations, therefore these figures should be treated as the best available estimate of sediment reductions to date.
Each wet season sediment is washed into local waterways and out to the Great Barrier Reef (GBR).
Most sediment is very fine, and can stay suspended for a long time and can travel great distances. Valuable topsoil is lost from production, and increased concentrations on the reef can be harmful to seagrasses and corals.
Landholders in the BBB have completed 69 on-ground water quality practice changes, and it is estimated that these have contributed a fine sediment reduction of 6,154 tonnes per year from reaching the GBR.
Of this, approximately half of the sediment savings are attributable to grazing land management changes on hillslopes and streambanks, and the other half as a result of gully remediation treatments across a broad range of scales, as shown in the graphs above.
The table below also highlights the relatively small area of intervention in the gully management projects compared to the large sediment savings that these can achieve - 60 per cent of the sediment savings over only 4 per cent of the project area.
Table 1. Estimated sediment reductions (tonnes) from projects completed in the LDC Project to date.
*GLMWW = Grazing Land Management Wire and Water
*The Exploring New Incentives activity area has provided an opportunity for graziers to adopt improved land management practices through a range of activities. For some of these properties, it was the first time they signed contracts for on-ground works.
The LDC project monitors four gully sites (represented in this table) with gold standard equipment and analysis, carried out by CSIRO.
Results have been compiled in a preliminary report from Bartley et al (2020), with the final report expected to be released by the end of 2020. The preliminary report shows all four sites have indicators of improvements, notably the Strathbogie and Mt Wickham sites.
More than 90 per cent of land in the BBB is used for grazing. The BBB Grazier Support program aims to provide all local graziers with education, training, technical support and incentives to help them adopt improved land management practices.
MORE than 20 grazing properties across the BBB catchment are taking part in the whoa boy project. LDC hosted landcare specialist and plant operator Darryl Hill to deliver erosion control grader training to landholders and local contractors who are now undertaking erosion control works across the catchment.
THE Collinsville small vehicle washdown facility was officially opened in October by Cr Peter Ramage, Whitsunday Regional Council (WRC). The facility, in Darby Munro Park in Collinsville, is available for anybody to use and is designed to reduce the spread of weeds such as prickly pear and lantana across primary production land in the BBB catchment.
GRAZING practice change is central to the Landholders Driving Change (LDC) project because it is the proven most cost-effective way of improving water quality. Graziers can adopt a wide range of activities to help meet water quality targets.
LDC works closely with landholders to investigate a range of approaches that reward good practice, and identify which options to pursue in the BBB. These could include market-based approaches such as grants, concessional loans, insurance mechanisms, stewardship payments, stamp duty relaxation, rate rebates, taxes, levies or market premiums. Some practice changes may only require short-term financial assistance, while others may need additional support to help maintain long-term benefits.
EXPLORING New Incentives is an important component of the LDC project, working with landholders to investigate a range of approaches that reward good practice. LDC engaged CSIRO along with James Cook University and Natural Decisions to research and scope potential institutional arrangements that are realistic in the short term to support ongoing improved practice adoption and landscape remediation over the medium to long term. That report and recommendations is now complete.
MORE than 90 per cent of land in the BBB is used for grazing. The BBB Grazier Support program aims to provide all local graziers with education, training, technical support and incentives to help them adopt improved land management practices.
LAND access laws for government agencies and utility companies who access properties in North Queensland must be strengthened to safeguard farmers’ best interests, graziers say.
BURDEKIN graziers are adopting management practices for a more sustainable and productive farming future – and the 2016 results prove it. The estimated annual average total suspended sediment lo
GULLY erosion causes approximately 65 per cent of the fine sediment load that comes from the BBB. The Landscape Remediation program aims to develop fast, effective and economical approaches to gully remediation.
LANDHOLDERS Driving Change is conducting a large-scale gully remediation project on Mt Wickham. LDC staff walked the landscape with local contractors and representatives from ecological engineering firm Verterra, a principal partner on the project, who developed the gully remediation technical design.
PROBLEM gullies are the focus of the first Landscape Remediation sites in the Landholders Driving Change project throughout the BBB catchment. Landholders could have possible sites assessed as part of the project. BBB landholders also have available a suite of funded on-ground works.
THANKS to the landholders who nominated potential gully remediation works, all of which will be will be assessed and prioritised. The aim is to develop fast, effective and economical approaches to gully remediation, drawing upon the knowledge of graziers and technical specialists.