Dam Failure Case Study: Wivenhoe Dam (Australia, 2011)

Beginning in October 2010, the Brisbane River system in South-East Queensland, Australia, experienced record floods due to a combination of a La Niña year and seasonal monsoons. In January 2011, the largest ever recorded inflows for Wivenhoe and Somerset Dams occurred and their flood control capabilities were tested for the first time. Due to discrepancies in the dams' flood operations manual, the operators were unclear which gated release strategy to employ at Wivenhoe. Even with this confusion, investigations showed that the engineers nearly maximized the dams' flood control capabilities. However, had more clear operational guidance been available, the operators could have engaged a higher release strategy sooner that would have slightly reduced flooding downstream. An investigation into the operators' actions lead to their exoneration of any criminal activity. After nearly a decade, flood victims won a class-action lawsuit against the dam owner for negligence. However, in September 2021, the dam owner won an appeal to the initial ruling. The plaintiffs are currently challenging the appeal through the High Court of Australia. This case study highlights several important topics from the event: 1) the dam operators faced challenging decisions when trying to implement operating orders under extreme flooding conditions; 2) investigations found that the operation manual for Wivenhoe and Somerset Dams was poorly written; and 3) several human factors relating to how the operation manual was written and operations during the flood itself played a significant role in how the event unfolded.