Burdekin on the Brink: Researchers Warn Lower Burdekin River Avulsion Could Come Sooner Than Expected

A group of senior researchers has raised alarm that the Lower Burdekin River could undergo a major channel shift far sooner than previously projected, directly challenging a government-commissioned assessment by Australian environmental consultancy Alluvium that found a “low short-term risk.” Known as an avulsion—when a river abruptly abandons its existing channel to carve a new course—the process can have serious consequences for communities, farmland and infrastructure. Researchers Eric Wolanski, Chris Hopper and Chris Cannavan warn such a shift could occur in the Burdekin within the next 50 years. “It’s not just a scientific question. It involves lives,” said James Cook University adjunct professor and oceanographer Wolanski. “It’s like playing Russian roulette with the lives of the people in the Burdekin.” Continued on page 5. Researchers Challenge ‘Low Risk’ Claim, Warn of Looming Avulsion Continued from page 1. Although rare on human timescales, both Wolanski and Alluvium agree an avulsion is inevitable in the Lower Burdekin; their assessments of its imminence, however, diverge dramatically. Alluvium, commissioned under the Queensland Government’s Burdekin Water Plan, reported in 2025 that an avulsion posed no immediate risk to the region. The assessment drew on aerial LiDAR mapping from 2009 and 2018, hydraulic modelling and geomorphic analysis, concluding the lower Burdekin River was rarely engaging its floodplain and short-term risk was low. However, several researchers have challenged both the methods and conclusions of the assessment, citing recent on-ground survey data that indicates significant riverbed aggradation, which they argue could drastically accelerate avulsion risk and bring serious consequences sooner than suggested in the report. Led by Wolanski, the group argues that major flooding events since the 2018 data used in Alluvium’s assessment—including those in 2019 and 2025—have facilitated approximately 0.7 metres of riverbed aggradation. The accumulated sediment raises the riverbed, reducing channel capacity and increasing floodplain connectivity during high flows, which together accelerate the likelihood of the river abandoning its current course. Wolanski’s team based their conclusions on RTK-GPS surveys along multiple river transects, a technique that can measure elevation changes to within centimetres. Hopper, a volunteer researcher from Townsville, says this method is far better suited than LiDAR for detecting changes to submerged riverbeds in turbid systems like the Burdekin due to its ability to directly measure the actual riverbed under water, rather than relying on surface reflections. Based on observed rates of aggradation, the group estimates an avulsion could occur within decades rather than centuries, potentially within the lifetime of current residents, in the event of another major flood. “It could severely impact farmland, houses, roads, and the railway if the river carves a new channel through the area,” said professor Wolanski. Cannavan, a Home Hill cane farmer with family roots in the region dating back almost a century, says the town could be “right in the firing line.” “I hope our findings are wrong,” said Cannavan. Alluvium has strongly rejected the group’s suggestion that an avulsion is imminent. In a written response, the firm said avulsions on the Burdekin are rare events that typically require frequent, high-energy floodplain engagement—conditions it argues do not currently exist. Alluvium acknowledged claims that LiDAR cannot directly measure submerged riverbeds but said it was used to assess broader reach-scale trends using exposed bars, banks and water-surface elevations during low-flow conditions rather than the riverbed itself. The consultancy also noted its 2025 assessment predated the major 2025 flood and did not include post-2018 impacts, but said preliminary aerial imagery showed only modest changes and no clear evidence of floodplain scour that would materially alter conclusions. University of Adelaide professor Kathryn Amos, whose work with the Burdekin River spans decades, said the disparate findings reflect the river’s notorious difficulty to study. “The challenge with the Burdekin is that it’s extremely difficult to measure,” Amos said. “It’s dry most of the year, and when the big floods come through, it’s often too dangerous to collect data. “There have only been a handful of studies that have actually measured how sediment moves through the Burdekin river, which means there’s a lot of uncertainty when we try to predict future behaviour. That uncertainty is why different teams of scientists can look at the same system and come to different conclusions.” Despite conflicting conclusions, both groups agreed that further research on the Lower Burdekin River was essential. “In previous work for the Queensland Government, we recommended repeat, ideally annual, channel topographic surveys to detect trends in erosion and deposition,” said the Alluvium spokesperson. “Such monitoring would provide the evidence needed to distinguish short-term variability from long-term change. If sustained bed aggradation relative to the floodplain were identified, this would indicate increasing avulsion risk over time and warrant reassessment.” A spokesperson for the Queensland Department of Local Government, Water and Volunteers said the Burdekin Basin Water Plan is developed using the “best available science and up-to-date hydrological modelling.” “Alluvium Consulting assessed sediment transport and avulsion risk in the lower Burdekin River and found the likelihood of a shift in any given year or decade is low. The assessment remains appropriate to guide current water planning and regulatory approaches,” they said. The plan is under review, with ongoing monitoring intended to protect river flows and support sustainable management of the catchment.