Bribie Island report blames human activity for accelerating erosion

The Queensland government has released the first stage of a much-anticipated review into erosion on Bribie Island, finding human activity has sped up natural coastal reshaping.

The review, led by coastal engineering experts RPS and International Coastal Management, gathered data from more than 200 historical and technical sources.

It reported that the period of “significant” human impact spanned roughly 250 years and coincided with increased settlement around Brisbane.

The 2022 breakthrough has widened in the three years since ex-tropical cyclone Seth ripped it open.Credit: Caloundra Coast Guard

Bribie Island, at the north edge of Moreton Bay, was first split in 2022 amid rough surf brought on by ex-tropical cyclone Seth.

Water broke through in two more places this year, when ex-tropical cyclone Alfred hovered off the south-east for several days.

Locals had been calling for action over the “highly dynamic” Pumicestone Passage, which runs between the island and the mainland, for several decades as changing tidal flows thinned and almost closed up sections of the waterway several times over the past century.

The report notes that parts of Moreton Bay have been dredged for navigational access since before 1865.

Other practices described as “relatively impactful” were logging and farming in the Pumicestone Passage catchment, and clearing mangroves and hunting dugongs in the bay itself.

The state government released a study into the waterway in 2023, and has conducted routine water testing in the passage since the first breakthrough disrupted tidal flows.

The review’s first stage found previous studies and reporting had been “robustly objective” and transparent with the data.

The first Bribie Island breach (top), caused by ex-tropical cyclone Seth in 2022, has now widened to about 2km, with Alfred causing more breakthroughs (bottom) in March this year.Credit: Bluey's Photography

Its second stage – expected in August – would now focus on solutions, with the government promising short-term stop-gaps and long-term action.

The minister for state development, Deputy Premier Jarrod Bleijie, promised community feedback would “directly shape” the review’s second stage.

The report attracted more than 1200 community submissions during its public consultation phase.

“We know it’s a big concern for many Caloundra residents, with the second and third breakthrough coming through now … and that’s why we launched an independent inquiry,” Bleijie said.

Sandbags outside the Caloundra Power Boat Club, where Golden Beach was eroded during ex-tropical cyclone Alfred.Credit: Catherine Strohfeldt

“This process is about delivering practical solutions that reflect both expert advice and community priorities.

“I hope we’ve shown the community that we have got down to business straight away.”

Last month, Sunshine Coast Council also announced plans for a 208-metre-long sea wall in front of Golden Beach, with the state and federal governments pitching in to fund the project.

The wall was expected to extend from Nelson Street in Caloundra to the TS Onslow Naval Cadets site, sheltering waterfront suburbia directly opposite the 2022 breach.

The area is badly affected by the new waterway inlet, with wave activity easily eroding the tidal beaches and causing structural damage to waterside buildings, as happened to the Caloundra Power Boat Club during a storm surge brought on by ex-tropical cyclone Alfred.

Councillor Terry Landsberg, who represents the Caloundra community, said the wall would protect the valuable park, coastal pathway and road.

A model has already been built and tested at Manly Hydraulics Laboratory, with work expected to be completed by early December.

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