The CSIRO’s Chief Scientist responsible for flood resilience planning in the Northern Rivers has rejected claims that “nature-based solutions” are being ignored.

Greens councillors at Ballina Shire and Rous County Councils recently argued that the current shortlist for consultation consists only of engineering projects. They tried unsuccessfully to move motions calling for more ecological measures to be added.

But Dr Jai Vaze told The Byron Bay Echo that three nature-based projects were funded in the first round of flood works after the 2022 disaster.

“They are already being implemented and we are waiting on results,” he said.

 “The current shortlist reflects the projects that require detailed hydrodynamic modelling, not those already funded.”

Research backs ecological measures

Dr Vaze is no opponent of ecological approaches. He recently peer reviewed a landmark study from the Australian National University looking at the effectiveness of nature-based flood solutions.

The study found that measures such as large-scale tree planting can help reduce flood peaks, depending on the catchment.

South Ballina Flood Channels

One controversial idea raised during community submissions is the opening of creeks south of Ballina to allow Richmond River floodwaters to flow directly to the ocean.

Dr Vaze said this was not a CSIRO proposal but a suggestion that came from the community during Phase One of the project.

“Boundary Creek and others have always acted as natural outflows during major floods,” he said. 

“Any intervention would require a detailed business case and environmental assessment before funding decisions are made.”

Bagotville barrage concerns

Critics have also claimed that upgrading the Bagotville barrage could worsen fish kills in the Tuckean Swamp. Dr Vaze said the intent was the opposite.

“The proposal is for a new control gate to prevent floodwater stagnation,” he explained.

 “It is that stagnation which leads to blackwater events and oxygen depletion.

“The aim is to improve flows, not worsen them.”

Assessments still to come

As previously reported by Ballina News Daily, all shortlisted projects will need full environmental assessments before proceeding.

Dr Vaze emphasised that CSIRO’s role is limited to science and modelling.

“We provide the evidence; government makes the policy and funding decisions.”

Looking ahead

A full catchment-scale flood model was released in June, confirming it can replicate past flood events across the Richmond catchment.

Over the next year, CSIRO will test “bundles of options” to identify which combinations best reduce flood heights without creating unintended impacts.

Findings are due in mid-2026.

Dr Vaze added that CSIRO is liaising with the Northern Rivers Watershed Initiative on soil health, water quality and revegetation.

“The aim is to bring the basin back closer to natural conditions,” he said. 

“But no single measure, ecological or engineered, will prevent another catastrophic flood on its own.”