Abstract
Floods are caused by a wide range of meteorological and environmental factors and issues around infrastructure and land use, resulting in various environmental, social and economic ramifications for societies. Brisbane, Australia, is a key example of a highly urbanised and dense city that is threatened by floods due to its location on the Brisbane River floodplain, which also exposes it to a myriad of sub-tropical climatic patterns. Hence, flood risk management strategies are used by authorities, institutions and communities to address and mitigate potential flood risks. However, the unpredictable nature of floods, diverse priorities of governments and differing institutional structures hinder the development of a standard framework for flood risk management thus different combinations of approaches are used to suit the local context. Moreover, technology and knowledge advancements have led to growing global shift towards using more nature-based solutions such as Blue-Green Infrastructure (BGI) to help support current flood risk management efforts.
This research aims to explore the flood risk management strategies used after the 2011 Brisbane floods and to investigate the capacity for BGI in this management. A qualitative approach was used to investigate the primary case study of Brisbane in comparison to the secondary case study of Singapore, another high-density city that experiences flooding and incorporates BGI within its flood risk management at a national scale. As there are different mechanisms used to mitigate flood risks, it is important to identify how BGI can be implemented to effectively support existing infrastructure. Research methods included a literature review around flood risk management, BGI and the contexts of Brisbane and Singapore; a detailed analysis of planning and policy documents; and semi-structured interviews with academics, consultants and Brisbane City Council (BCC) staff.
The analysis of policy and planning documents identified that flood risk management strategies differed according to the individual document’s purpose, wherein the BCC uses more types of strategies and incorporates a medium to high level of BGI in their documents compared to the Queensland (state) and Australian (federal) Governments. Although there is considerable incorporation of BGI in the BCC’s plans there is still significant overlap in the Queensland Government’s policies, hence the planning environment and its documents would benefit from being streamlined for clarity.
In contrast, the Singapore Government’s documents and approaches demonstrated consistent strategic preferences within a centralised integrated stormwater management approach with a high level of BGI integration throughout. Interview findings highlighted the value of the BCC’s flood risk management strategies but called for more accuracy, with the effectiveness hindered by complex challenges of differing levels of risk perception and literacy; deficiencies in planning and decision-making processes; and strong development pressures. Existing BGI initiatives such as that of Oxley Creek and Norman Creek were seen to be successful, albeit slow in growth. This slow uptake was suggested to be due to vested interests, funding constraints, and a lack of clarity in its maintenance and communication of its benefits. Singapore’s flood risk management approach, conversely, was noted for its centralised and proactive governance, planning efficiency, stable funding and efficient public communication, although public involvement needed to be improved upon. Singapore’s Active, Beautiful, Clean Waters Programme was highlighted as an example of a successful national BGI initiative for Brisbane to formulate approaches that can be implemented at a wider scale.
Brisbane and Singapore have demonstrated different strengths and weaknesses in terms of flood risk management and BGI. Flood risk management in Brisbane, particularly its BGI implementation, can be improved with learnings adapted from Singapore’s strengths, and vice versa. The BCC has demonstrated significant efforts in diversifying its strategies and enhancing the level of BGI to address flood risks, however for these efforts to persist, local and state government decision-makers should also address political priorities that favour development over flood risk planning, provide more robust flood risk management controls and risk indicators, and work towards transitioning to more holistic and integrated flood risk management frameworks.