New evidence has emerged suggesting the monster floods that devastated Grantham four years ago was a man-made disaster that could have been avoided, 60 minutes reports.

Helicopter flight logs from the Nine News chopper add to a growing inventory of evidence that locals say was ignored by the commission set up to investigate the causes of the 2011 Queensland floods.

Grantham, in the Lockyer Valley, was described as a "war scene" and "completely and utterly devastated" by the January 10 flood that killed 12 people in the town of 300 residents.

Relying heavily on the expert evidence of hydrologists, the commission's final report concluded that the Grantham quarry wall might have lessened the impact of the floods.