Blame game on dam
THE Queensland Government says an inquiry will determine if the operators of Wivenhoe dam contributed to Brisbane’s January floods, after SeqWater blamed weather forecasters.
The government has released Seq Water’s self-examination of its operation of Wivenhoe and Somerset dams in the days leading up to the city’s devastating floods.
A commission of inquiry is looking at whether dam releases in the days leading up to the floods exacerbated the scale of the disaster, and if more water should have been released sooner.
In its report, to be considered by the inquiry , SeqWater said it operated Wivenhoe i n accordance with the manual that applies during f l ood events and pointed to inaccurate weather forecasts.
It said six out of eight threeday forecasts between January 6 and January 9 dramatically underestimated rainfall.
‘ ‘ These underest i mated rainfall forecasts did not support an increase in flood releases above that undertaken,’’ says the 1180-page report.
SeqWater said that with hindsight, three and five-day forecasts were merely an indication of future rainfall.
‘‘ And these forecasts cannot be used as a basis of flood operations’ decision-making where public safety in both rural and urban areas is directly impacted,’’ it said.
However, it said the dam mitigated the impact of the ‘‘ very large and rare’’ flood.
Without it, water would have been two metres higher than it was at the CBD’s Port Office gauge, it said.
Department of Environment and Resource Manage- Questions have been asked about water released from
Wivenhoe Dam ment Director-General John Bradley, the regulator of dam safety, said people could draw their own conclusions from the report.
It was up to the inquiry to determine if more water should have been released earlier, and whether the manual that governs dam operations needs revision, he said.
‘‘ When SeqWater was releasing those very large volumes then, its engineers were operating under a manual that was trying to avoid any risk of dam failure,’’ Mr Bradley said.
‘‘ If you have dam failure, t hen f or t he community downstream of the dam we can have catastrophic damage and lives lost.’’
He said the operating manual was last updated in 2009, and SeqWater had identified five areas where changes might be justified, although more analysis was needed.
Opposition natural re-sourcesspokesman Jeff Seeney said the report reinforced the view that dam releases were ‘‘ grossly inadequate’’ and it was ‘‘ very obvious’’ that more water should have been released earlier.
‘‘ The question is why they didn’t.’’