Many areas in Australia have recently faced major flooding following a long drought period. Whilst policies are in place to manage the impact of flooding including achieving appropriate flood immunity levels for development and minimising the impact of development on flooding – it is evident that many areas are at risk of flood inundation and its associated damage to homes, businesses and infrastructure.
The United Kingdom has also faced these issues with 1 in 6 (5.2 million) properties currently assessed to be at risk of flooding. A number of large flood events over the past 12 years led to a significant rethink in the approach to managing flood risk in the UK. One of the major changes relates to the improved links between development planning and flood risk management.
There was a renewed recognition that inappropriate spatial development has the potential to provide a triple threat to flooding by adversely affect flood sources (through increased runoff), flood pathways (through interference with defence and flowpaths) and receptors (by increasing the loss and damage caused by flooding). The Planning Policy Statement 25 on development and flood risk, has now evolved from an earlier planning guidance to prevent inappropriate development with respect to flood risk. At all stages of the development planning process, this planning document requires planning authorities to apply a risk-based sequential approach to the zoning and allocation of development land to ensure developments are placed at locations with as low a risk as possible depending on their potential vulnerability.
This paper will describe how planning policy and its implementation in the UK has evolved. Case studies will be used to illustrate particular aspects and draw out lessons learnt from its implementation. Potential refinement of Queensland policy to incorporate changes will be considered with discussion regarding the implications of such changes.
Miss Trinity Graham
Principal Water Engineer