Bundaberg’s controversial Paradise Dam will need to be completely rebuilt after investigations found the wall has “too many issues” to be repaired.

Experts investigating restoring the dam’s wall, which was lowered by 5.8 metres in 2020 due to safety concerns, have told the state government it cannot be mended or reinforced. 

Instead, operator Sunwater has recommended the wall be wholly replaced immediately downstream of the current structure. 

“The concrete quality of the dam means it cannot be repaired to last the many decades we expect from these assets,” Sunwater chief executive Glenn Stockton said.

“Sunwater understands the importance of public assets like this — they need to perform day-in, day-out.

He said the work to lower the wall had reduced the risk of a failure, but the original plan to raise it again could not proceed.

“That was being done by raising the height of the existing structures and reinforcing those structures by buttressing with additional concrete around them,” he said. 

“Our investigations have concluded that is not feasible.

“The structure that is currently there would not allow us to do that successfully and certainly wouldn’t allow us to do that over a period of time that gives us confidence into the future”

Return to capacity delayed

Early work on returning the wall to its original height began in 2023, with the state and federal government both committing to funding half of the $1.2 billion project. 

Major work was due to start in 2024. 

“We can’t continue to go down a path and look to work on an asset that’s compromised and not come out with an outcome that people have confidence in going forward,” Mr Stockton said.

“It’s a replacement structure in a sense that it returns the storage back to 300,000 megalitres.”

He said while some of the work from the restoration project would be used in the new build, it could take at least two years to work through new designs and environmental approvals.

“To be thinking that we need to do this sort of work on an asset that was relatively young in design terms is disappointing for us.

“But we needed to make a decision now to give ourselves and our customers and the community confidence in Paradise Dam of the future.” 

Damned from the start

Built in 2005, the dam on the Burnett River about 100 kilometres south-west of Bundaberg, is the main water storage supplying the region’s agricultural industry.

It suffered significant damage during record flooding in 2013, and subsequent remedial works failed to address safety concerns. 

In 2019, Sunwater announced the wall height would need to be reduced immediately to overcome structural issues, shocking irrigators who criticised the lack of consultation on the decision. 

A subsequent Commission of Inquiry reporting to the state government found the original design, which was the first in Australia to use roller-compacted-concrete (RCC), was “incapable of meeting the required design values”.

No budget has been outlined for the rebuild project, but in a statement, Queensland Minister for Water Glenn Butcher said a business case had been started and new environmental approvals were being sought.

“The Queensland government will always listen to the experts and the expert advice tells us we cannot repair the existing dam wall,” he said. 

“Reliable water supply is critical to jobs, growth and liveability in regional Queensland.”

He said early works at the site would continue “to ensure the new dam wall can proceed as quickly as possible, once all approvals have been obtained.”

He said the timeline and cost of the project would be confirmed once the business case and approvals were complete.