Floodplain Manager December 2019/January 2020


This edition of Floodplain Manager was supposed to be completed at the end of January but like many other businesses in Eastern Australia we were indirectly disrupted by the bushfires which affected some of our staff to varying extents.  Our hearts go out everyone who has been badly affected by the fires.

At that time I was contemplating an editorial which reflected on some of the bushfire impacts and the lessons they have for floods.  For example:

  • Widespread, long duration natural hazards become increasingly difficult to respond to as time goes on because so many of our emergency responders are volunteers and the bigger the event the more of their own homes and/or businesses are directly affected. We witnessed this to some extent with the 2011 floods.
  • There will always be an “unprecedented” natural disaster because not only do we have limited records of natural hazards under recent past climatic conditions but future climatic conditions and development projections mean that more people will be in greater harm’s way. In 2011 the most extreme floods missed our large population centres and the Brisbane flood was small compared to what it experienced in the 1800s.  A “record flood” in any one of our large cities would be catastrophic.
  • After Cyclone Tracy flattened Darwin in 1974, the Australian Standards and building codes were upgraded and in recent cyclones buildings built and maintained to those stood up well. Although the data is not yet in, I expect that houses built and maintained to the bushfire design codes that have evolved in recent decades had a better survival rate than their older neighbours.  Yet despite overwhelming evidence that modern house designs fail dismally in floods we still have not moved to mandate any meaningful flood resilience in building design.
  • The indirect and intangible impacts of natural disasters are often far more costly than the financial costs of damaged buildings, contents and infrastructure.
  • It takes years to recover from a natural disaster and some people, businesses, communities and ecosystems never really do.

What I wasn’t contemplating was that I would be writing an editorial the day after my phone had been pinging continuously with flood warnings and on a day when half our staff had their commute interrupted or cancelled because of flood impacts.

It is therefore timely that this month we report on an article published in Earth’s Future which provides a framework to adequately assess the risk of consecutive disasters and their impacts.  There are also several articles which update forecast sea level rise and its impacts around the globe, including in Australia and some case studies which suggest that relocation will be more cost effective than mitigation.  That is not surprising given that an inquiry into the cost of insurance in Northern Australia found it is becoming unaffordable because of the impacts of consecutive disasters.  I am sure the recent bushfires and floods will push insurance premiums along the East Coast in a similar direction.

We also report that floods accounted for more than one third of natural disaster losses globally in 2019 and displaced several million people.  The latter is likely to increase fivefold due to climate change by 2100.

We need to take the lessons from recent past and projections of the possible near future to work out how to reduce the impacts of natural hazards including floods.  What I like to refer to as climate- induced human change.

Steven Molino

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