Monitoring regime covers 24 gullies so far in the Bowen, Broken Bogie catchment
Since 2022, annual monitoring of 19 remediated small-scale and five large-scale gully sites within the Bowen Bogie Broken (BBB) catchment has been carried out, prioritising maintenance and managing maintenance works.
These gullies were remediated between 2017-2022.
Collectively, the works treated more than 11,000 linear metres of gullies eroding from 54 gully heads. Estimated sediment reductions from gully projects completed in the Landholders Driving Change (LDC) project was 5,536 tonnes.
The gully characteristics ranged from small-scale requiring minor interventions carried out by landholders, to large-scale remediation requiring engineered solutions using large-scale earthworks equipment.
The Queensland Government, through the Queensland Reef Water Quality Program, approved NQ Dry Tropics to use savings from the LDC project to go towards monitoring and maintenance of gully sites.
Eight sites — five small-scale and three large-scale gullies — required minor maintenance which was carried out during the past six months. This included fixing a breach in a diversion bank wall (see story below), slumps in rock chutes and check dams, and fixing rill erosion.
Apart from one site, the maintenance program was carried out by local contractors Hillery Group and Barry Collett Contracting. One of the small-scale sites was carried out by earthmoving contractor Mark Prichard, based near Ravenswood.
All sites will be monitored again after the wet season, from February to April 2025, making it the third wet season all sites have been monitored under this project.
The project wraps up in mid-2025, and a technical report will be produced detailing the monitoring framework, prioritisation process for maintenance works, site characteristics, results and learnings from each site.
Lead author NQ Dry Tropics Soil Conservation Officer Bernie Claussen presented preliminary findings to the LDC Project Panel meeting held in Collinsville in October. Panel members had an opportunity to provide input into the structure and content to be included in the document.
Dartmoor diversion banks do their job
A series of four diversion banks, each about 200 metres long, was constructed above the head of a gully at Dartmoor Station (pictured, right). The aim was to halt the progress of the gully heads.
Water is now being slowed and held on the natural terrace for longer instead of running directly into the gully system, improving water infiltration.
A breach occurred in the lowest bank where there was a change of soil type. Thanks to earthmoving contractor Mark Prichard and son Sam, based near Ravenswood, the hole has been converted to a wide level weir that will help spread the water, slow the flow and reduce its erosive power.
Similarly, at the second lowest bank, the exit point was too narrow, resulting in rill erosion which, if left, may have developed into a gully. The solution was to create a wide, level outlet; much the same as required for a dam bywash.
Shallow rills in the natural rock channel that takes the runoff water once it has passed through the four banks, was filled with rock to armour the entry. The gaps between the rocks allow water to flow through, slowing the water down and reducing its force.
The Dartmoor project site was one of 25 gully remediation projects completed between 2017-2020, through the Burdekin Major Integrated Project (Landholders Driving Change).
The Burdekin Major Integrated Project Gully Maintenance and Monitoring project is funded by the Queensland Government, through the Queensland Reef Water Quality Program.
