Commissioner finds the Grantham quarry did not cause or materially contribute to the Grantham floods
On 10 January 2011, the town of Grantham was inundated by flooding which swept away houses and killed 12 people, making it one of the most deadly natural disasters ever to hit Queensland.
Walter Sofronoff QC, the Commissioner of the Grantham Floods Commission of Inquiry (‘the Commission’), has today presented his report to the Queensland Premier. The Commission was established in May 2015 to conduct a full inquiry into whether any natural or man-made features of the landscape surrounding Grantham could have altered or contributed to the flooding which occurred, in particular whether the existence or breach of the Grantham quarry caused or materially contributed to the flooding.
This was the key focus of the Commission as concerns had been raised by the Grantham community that the quarry had, over time, made a significant alteration to the natural landscape, and therefore the natural flow of water in a flood.
Prior to the flood, stockpiles of material had been placed around the quarry pit and a high ‘bund’ had been constructed which was made of dirt and prevented the ingress of water into the quarry, directing any water along the natural course of the Lockyer Creek. The quarry was owned by Wagner Investments Pty Ltd at the time of the flood.
After extensively considering the expert geotechnical and hydrological reports, the Commissioner concludes in his report that the flooding occurred in the way that it did because of the combination of the volume of water that surged down Lockyer Creek after rain was dumped in its upper catchment and also due to the natural shape of the land near Grantham. The only effect the Grantham quarry had was to marginally increase the water level immediately upstream of the quarry by about 20 centimetres and to slightly delay the commencement of the flooding downstream by a few minutes while the quarry pit briefly absorbed part of the flow. As the Commissioner noted in the report:
“Quarry or no quarry, railway line or no railway line, if there is ever another sudden dump of water in the upper catchment of the Lockyer Creek of the order of that which fell on 10 January 2011, the same thing will happen again…The flood of 10 January 2011 was a natural disaster and no human agency caused it or could have ever prevented it.”
This report comes after the Honourable Justice Catherine Holmes (as she then was) presented a report, as the Commissioner of the Queensland Floods Commission Inquiry, to the Queensland Premier in March 2012 dealing with the Statewide flooding events which occurred in 2010 and 2011.