'Dams no silver bullet'
MARY Valley resident Steve Burgess has taken issue with proponents of a raised Borumba Dam, but says dams are not always a bad thing.
In a report presented to the Mary River Catchment Co-ordinating Committee yesterday, Mr Burgess says it is nonsense to claim that a raised Borumba Dam would have reduced by almost one-third the volume of flood water that inundated parts of Gympie Region recently.
The claim was made in a recent article in The Gympie Times by John Hodgkinson, a long-term advocate of a raised Borumba Dam.
"It's good there is a conversation about this, but it needs to be an informed conversation," he told the paper yesterday.
"Dams aren't magic. They can't produce water out of nothing and they can't make water go away - they are just a way of helping us manage what water is there.
"Nothing makes them all bad dams and nothing makes them all good and the more accurate the information, the better the decisions that can be made."
Mr Burgess told the MRCCC he did not accept that even a much higher dam wall at Borumba would have had the effect claimed by Mr Hodgkinson.
"Every single number and hydrological calculation presented in that news article was incorrect," he said.
Mr Burgess said the Borumba Dam catchment area was about 16% of the catchment upstream from Gympie, with great variation in rainfall over much of both areas.
"Even if a dam at Borumba could somehow prevent all the water in its catchment from ever reaching the Mary, the height of the flood peak at Gympie would be reduced by much less than 16%," he said.
Mr Burgess reported that the 16% reduction in flood flow which might be achieved would result in less than an 80cm reduction in flood height.
Explaining his views, he said there was a great difference in considerations of flood mitigation and water supply.
Water supply figures would not include water inputs from areas used to supply Brisbane, but flood figures would involve water coming from all areas.
"The numbers in the Gympie Times article were so much at odds with what most MRCCC delegates understood."