The 2013 floods show a striking resemblance to the weather system that generated the 2011 floods. A small cyclone in North Queensland (Tasha in 2010, Oswald in 2013) moved down the east coast bringing extensive rainfall. The difference is this year the rainfall was preceded by extremely dry conditions. There was greater capacity for the rain to soak into the ground, while for the most part rivers had not begun to flow.
But for households in the path of the latest floods it was, “here we go again”.
Following the 2011 floods there was a great deal of emphasis on the role of planners. The second volume of the Queensland Floods Commission of Inquiry was dominated by the planning process and the responsibilities of planners and local governments for the vulnerability of communities that were inundated. The inquiry didn’t apportion blame, but it did make many recommendations to improve land-use planning.
Before urban development can be constrained to avoid flood risk, an expensive exercise in floodplain mapping needs to take place. The Queensland Reconstruction Authority played an important role in establishing the basis for this.
But in the meantime, places that were vulnerable to the 2011 floods remained vulnerable this year. Future changes in land use will only slowly alter flood vulnerability.
Coastal and floodplain policy have seen introduced the idea of three strategies: retreat, accommodate or protect.
The “protect” part involves building things like levees, rock walls and drainage channels. Unfortunately levees will only work in the short to medium term and are expensive to construct and maintain.
“Accommodate” strategies take in the mitigation, hazard preparedness and community awareness that get ordinary households, councils and emergency services better prepared for the next hazard event. This group of strategies include warnings, awareness campaigns, community education, preparing evacuation centres, emergency and evacuation plans and kits, maintenance and retrofitting of houses and property and the building and encouragement of community resilience.
“Retreat” strategies place responsibility on to planners, councils and state government, as well as individual households. In the face of regular flooding and inundation some locations are simply going to be unsustainable. This will become even worse as climate change brings about sea level rise which will extend up tidal estuaries into city centres, and bring an increase in severe storms and floods.
Retreat will involve decommissioning and abandoning extremely vulnerable locations. The Grantham relocation scheme is one such example of a community moving away from the floodplain onto adjacent elevated land. Such schemes are going to be expensive because they will require councils or governments to buy back land and property from residents. To date, buyback schemes have not been either popular or particularly successful, but in the long term we are likely to see more of these types of relocation.
In anticipation of these processes of worsening floods and inundation, researchers from James Cook University, Macquarie University and the University of Southern Queensland carried out a number of post-flood studies over the last couple of years.
We looked at the experiences of households in Charleville and Mackay after the 2008 floods, and Emerald, six flood-affected suburbs in Brisbane and Donald in Victoria following the 2011 floods, as well as communities in North Queensland following Cyclone Yasi and floods.
In all of these surveys we asked people whether they might consider relocating either elsewhere in the town or to a completely different town or city if they endured further floods in the future. For small places like Charleville or Donald there is not much option of finding a less flood-vulnerable location within the town. In Donald only 8% of households thought that they would move in the coming years, but in Brisbane 21% considered they might move and in Emerald 24% considered it likely. In Charleville and Macquarie we asked the question of businesses as well at households.
In Ingham and Innisfail in North Queensland we asked a similar question following floods in Ingham and Cyclone Larry at Innisfail. Ingham is very regularly flooded, so that it is part of the experience of living in the town. Still, around 10% of the population is considering leaving the place. In Innisfail, which recorded a net decline in population after cyclones Larry and Yasi, between 20 and 30% of the population is considering relocation.
Then at Mission Beach after cyclone Yasi we asked residents “In the near future are you likely to relocate in order to decrease or negate you or your family’s vulnerability to coastal hazards like storm surge?” This represents a direct retreat strategy: 19% of the households responded yes, they would be likely to relocate.
In all of these surveys the majority of the population clearly stated that they were not likely to move. This is what we expect and it’s a measure of the resilience of the communities. However, the proportions of households who expressed a serious consideration of leaving the community in the face of future disasters represents a significant impact upon the economy and long-term sustainability of their towns. It also represents a willingness to participate in retreat and relocation strategies.