The Queensland government's dam expansion plans could prove unequal to the task of preventing the damage caused by severe flooding events in future.
The Queensland government has unveiled the measures it is considering to reduce the impact of heavy storms and flooding,in the state including alterations to the Wivenhoe Dam and the construction of as many as eight new dams.
Premier Campbell Newman said that the government had identified eight locations where the construction of dams had the potential to safeguard thousands of houses and businesses.
These potential dam sites include upper Brisbane River near Linville, the Cooyar Creek near Bernarkin National Park, Emu Creek near Harlin, the Bremin River near Mount Walker, the Stanley River near Peachester, Tenterhill Creek near Gatton, Lockyer Creek near Murphy’s Creek and Cressbrook Creek near Kipper.
Other measures could include raising the level of bridges beneath Wivenhoe Dam, which was built across the Brisbane River to protect south-eastern Queensland in response to disastrous flooding in 1974.
“Before the next wet season, south east Queensland residents should have confidence in the fact that if there is a flood event, dam operating decisions will always place greater value in life, then people’s homes, businesses and livelihood – and then public roads and bridges,” said Energy and Water Supply Minister Mark Mark McArdle.
The government’s announcement comes just as the approach of Tropical Cyclone Ita further highlights the vital importance of storm and flood prevention measures as a result of rapid climate change.
Ita has already compelled the government to evacuate low lying areas between Port Douglas and Cape Grenville, which is the cyclone’s expected landfall site, while Premier Newman has urged those residing along the coast not to “underestimate the rain,” and promptly leave their homes when urged by authorities.
While the state government is currently pursuing damage mitigation measures in earnest following severe flooding in Brisbane several years ago, some critics say that these efforts will likely only have limited impact on major population centres in the south-east of Queensland.
Chas Keys, a flood management researcher and consultant who is an Associate of Risk Frontiers at Macquarie University, said flood levels in southern Queensland will only be brought down by modest amounts by the measures, given that the eight potential new dam sites are primarily sited on creeks which command only small proportions of the catchment system.
Much of the rain which fell during the 2011 floods fell well below the sites outlined by the Queensland government, over areas including Lockyer Creek, Bremer River and Oxley Creek.
According to Keys the chief cause of the flooding disaster of January 2011 was the imprudent decision to pursue residential and commercial developments on low-lying flood plains, pointing out that even Premier Newman acknowledges that it is well-nigh impossible to fully flood-proof Brisbane and Ipswich given their geographic particulars.