As the floodwaters start to recede and we take stock of the damage caused by the recent floods, a show of defiance is always tempting. “We are going to build it all back”, is the default reaction of authorities. But is this wise or smart?
Professor Jamie Pittock from the ANU Fenner School of Environment and Society has pointed out that as far back as 1817 Governor Macquarie was lamenting that settlers were continuing to reside on spots in the valley which were subject to floods, “and from whence they have often had their prosperity swept away”.
Not only does the Hawkesbury-Nepean valley of western Sydney have a long history of floods, it has a future of them. The climate science is absolutely clear – in future we will experience more frequent, and more severe, extreme weather events of the kind we have just seen.
Given this background, the New South Wales proposal to raise the Warragamba Dam is the wrong way to go. Professor Pittock points out that, far from decreasing it, flood control infrastructure increases the danger and losses from flooding, by encouraging more downstream development, which in turn is flooded when design limits are breached by an extreme weather event.
Furthermore, raising Warragamba Dam will not prevent the frequent flood damage from tributaries entering the valley below the dam, including the Grose River and South Creek. It would also inundate part of the Blue Mountains World Heritage Area, and cultural sites of the Gundangara nation.
Dangerous floods will come again. As a number of other countries have realised, the safest approach is to keep people off the floodplain, and out of harm’s way.
The Hon. Kelvin Thomson
Sustainable Australia Party