An independent Commission of Inquiry has confirmed structural and stability issues with Paradise Dam near Bundaberg.
Natural Resources Minister Dr Anthony Lynham tabled the 563-page Commission report in Parliament, telling the House that the Government had accepted all eight of the commission’s recommendations for future projects.
“The Commission heard evidence about a litany of issues with the design and construction, some of which were ultimately found to be root causes of the present-day structural and stability concerns,” he said.
“The commission found that the design of the primary spillway apron is completely inadequate. It’s simply not wide enough.
“Evidence before the commission, suggested that if the 2013 floods had lasted longer, the erosion due to the insufficient downstream protection may have undermined the dam giving rise to a risk of a dam failure.
“Importantly, the Commission considers that Sunwater’s position in responding to the risks associated with the dam is reasonable.”
Dr Lynham told Parliament that issues raised in evidence included:
- segregation, density, compaction and the cleaning and curing of the surface of roller-compacted concrete layers during construction, also known as ‘lift’ joints.
- the concrete mix and its peak placement during summer weather which exacerbated constructability issues.
- a quality assurance tool, which masked, rather than highlighted, construction deficiencies.
- the treatment of and high number of cold lift joints. This is of concern, when lift joint strength is so important to the overall stability of the dam.
He said expert testimony also confirmed that more testing was needed to resolve doubts about the dam’s stability.
“This is consistent with the Building Queensland report findings handed down in March and preparations for testing is underway,” he said.
“As always the Government’s priority remains community safety – with Paradise Dam to continue to provide long term water security and underpin economic prosperity in Bundaberg and the Burnett for generations to come.”