Floodplain Manager October 2019


It is pleasing to hear that after a decade of static Federal Government flood mitigation funding (a decrease in real terms), an extra $50 million will be put aside to fund flood mitigation works and programs.  However, as I and others have often pointed out previously, this pales compared to the annual average $560 million disaster recovery bill.  When flood mitigation projects and programs are consistently shown to have an economic benefit to cost ratio of about 4 to 1 on average, investment in flood mitigation can be seen to be economically worthwhile.

Of course the economic benefits and costs of flood mitigation are only one part of the equation.  The trauma caused to people who experience losses during floods can be far more costly than the damage to the assets themselves.  Loss of life, injury, disease, post-traumatic stress and stress induced or aggravated illness can all be intangible costs of floods and many communities see increases in health care costs, drug and alcohol dependence and domestic violence as further flow on effects.  At the same time, the mitigation works themselves may have significant intangible impacts which need to be carefully considered.

This is the purpose of the current NSW Parliamentary Inquiry into the proposal to provide flood mitigation capacity on top of the water storage in Sydney’s Warragamba Dam.  At stake are the assets, lives and livelihoods of a hundred thousand people downstream of the dam and the heritage, ecological and wilderness values of thousands of hectares upstream of the dam.  To make the debate even more complex is the fact that there are also likely to be economic and ecological impacts downstream, as well as significant environmental and heritage benefits downstream, although these issues often seem to get lost as supporters and opponents try to make the issues more clear cut.

Of course the scale of the benefits and the impacts will only be realised when a flood occurs and again supporters and opponents often present either the benefits or the impacts as an inevitability, depending on what point they are trying to make.

One of the disappointments of my career was that when I prepared the environmental impact statement (EIS) for the original Warragamba Dam mitigation proposal 25 years ago, a political decision was made to shelve the proposal and not release the EIS for public comment.  I am not proposing or opposing the dam but what I want to see is informed discussion about these high stake issues and I think the parliamentary inquiry is a good first step.

Steven Molino

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