Can we beat floods?
A UNIVERSITY of Queensland flood expert has said all levels of government need to look beyond Ipswich when considering ways to protect the city from inundation by the Bremer River.
Professor Hubert Chanson, from the School of Civil Engineering, said Ipswich was in a unique situation because there was no reservoir on the Bremer.
While suggesting that a network of reservoirs or even a levy could be used to protect the city, he said any solution would need to consider the Bremer, Lockyer and Brisbane catchments as a whole.
“One of the difficulties is that the water level of the Bremer River is linked to the water level of the Brisbane River,” he said.
“The effect of the Brisbane River on the Bremer River can’t be ignored.”
In simple terms, the high water level and flow of the Brisbane River caused a back-up effect in the Bremer which, in extreme cases like the January flood, had an effect not only on the area near the junction of the two systems, but far back even beyond the Ipswich CBD.
Prof Chanson said this effect alone could have caused the Bremer River to rise several metres.
To give an example, the same effect was at play at the point where the Bundamba Creek met the Bremer River.
Residents in areas like Booval, Bundamba and North Booval were affected by steadily rising water rather than a fast-flowing torrent, because the water backed up.
While the water damage was just as bad, the flood water did not have the usual steamroller effect.
When asked if Wivenhoe Dam had contributed to the problem, Professor Chanson said the facts spoke for themselves.
“There are lots of opinions on Wivenhoe Dam and the role it played,” he said.
“But here in Brisbane, the flood was much lower than in 1974 and of much-shorter duration. I think Wivenhoe Dam reduced the level and the duration of this flood.”
Though still concentrating on the human aspect of the flood recovery, Mayor Paul Pisasale said he was willing to consider any option to reduce Ipswich’s vulnerability to further flooding.
He said environmental concerns were important in any debate about dams, but human concerns were paramount.
“I’m hoping the inquiry will address all these things. We need people to comment on this issue,” Cr Pisasale said.
“Before the Traveston Dam was allowed to go ahead there were people jumping up and down about lungfish; well at the end of the day it’s the people who need to decide what is more important.
“I don’t think there is any amount of pipes that could have dealt with the amount of water we saw last month.”