Australia-first stabilisation project on massive scale
AN Australian-first streambank stabilisation project on the Fitzroy River aimed at reducing sediment flow into the Great Barrier Reef during future flooding events is complete.
The $1.8 million project, delivered by Fitzroy Basin Association, was funded by the federal and state governments under the Natural Disaster Relief and Recovery Arrangements.
The need for such a project was identified in the wake of 2017's Severe Tropical Cyclone Debbie.
A 1.2km stretch of the Fitzroy River at Yaamba was prioritised by engineers as the site that would have the greatest long-term impact on reduction of sediment flow.
Misko Ivezich, environmental engineer from Alluvium Consulting oversaw the design and was confident the newly-established stabilisation infrastructure would fulfil its sediment reduction role and withstand another major flooding event if one were to occur.
Cameron Dick, Minister responsible for the Queensland Reconstruction Authority, said Cyclone Debbie's impact on the riverbank was substantial.
"The riverbank retreated approximately 20 metres, mobilising 266,000 tonnes of sediment into the waterway," Mr Dick said.
"It is estimated this project will save 90,000 tonnes of sediment from entering the river system with long-term benefits to not only the local waterways but also to the health of the iconic Great Barrier Reef."
Aerial surveys of the Fitzroy River following Cyclone Debbie identified Yaamba site as needing urgent repair.
FBA chief executive Elyse Riethmuller said historical records showed the Fitzroy River site had been in a retreating pattern for many decades, amounting to almost 350 metres lost since 1952.
"The most concerning element of this site was a distinct loss of natural vegetation along the riverbank, which is a vital natural barrier in avoiding erosion," she said.
"Without intervention, erosion would continue to accelerate, with modelling predicting that eventually, the river would have cut a new path across farmland, resulting in run off that would've deposited millions of tonnes of sediment into our waterways."
"The project relied heavily on partnerships with landholders, allowing local contractors onto private property throughout civil works, including excavation, bank creation, installation of pile fields and rock protection.
"In exchange, the project will protect the property from an ongoing loss of productive agricultural land."
The project created 12 full-time jobs in the region, and a collaboration with Rockhampton Regional Council and Livingstone Shire Council saw more than 75,000 native trees supplied to FBA to further stabilise the banks during the six-month project.
"The results will endure beyond our lifetime, protecting our natural assets and downstream communities for many generations to come."