Flood planning for the Brisbane Water foreshore has been, until recently, based on a single flood level derived from an historical ocean storm event. No allowance was given to the variation of flood levels around the foreshore or impacts of sea levels rise. In 2010 a hydrodynamic model was developed to simulate the wind, wave, flood flows and tidal forcing associated with an ocean storm. The output was detailed design event flood levels for the impacted areas of the foreshore.

The modelling identified that while the existing impact of ocean storms on urban areas is moderate, there is likely to be a significant increase in the impacts as a result of sea level rise. This raises the complex planning issues associated with protecting existing development against the future impacts of ocean storms as well as ensuring any future development is flood compatible.

The modelling results were analysed within the context of Council’s planning framework to formulate planning measures that can be put in place as a first step in achieving these goals, such as the inclusion of sea level rise in flood planning levels, the management of wave energy at the foreshore and controlling the density of development in future flood risk areas. Key planning issues were also highlighted as result of the analysis that require more detailed consideration as a ‘next step’, such as suburb wide planning for incremental filling and identification of sea level rise triggers in decision support tools.