Storm tides, coastal erosion and inundation
Authors: Peter Helman, Christine Metusela, Frank Thomella and Rodger Tomlinson
Throughout the 1950s until the mid 1970s, Australias east coast experienced a particularly stormy period, with many coastal communities experiencing severe erosion and flooding as a result of storm surges, storm tides, Topical Cyclones and East Coast Lows. This case study focuses on the adaptive responses of the Gold Coast, Byron Bay and the Collaroy/Narrabeen regions. Due to the high number of storms and the extent of impacts, councils in all three areas implemented protection actions and policies during and after this period. However, since the mid 1970s, calmer weather has prevailed and the knowledge of how to prepare and respond to storm tide impacts is in danger of being forgotten as the memory of past events fades. This study finds that risks associated with storm tides are not well reflected in planning or community attitude, generally because these conditions have not been experienced for 30 years. Increased vulnerability is likely to result from rapid development of beach-front areas since the 1970s, increasing the population at risk and reducing designated coastal reserves. Loss of corporate memory (staff turnover) has led to a gradual easing of planning policy restrictions. Planned retreat schemes are difficult to implement because existing property rights do not support these arrangements. If property buy-back schemes are relied on, arguably all properties in an at-risk area must be purchased to create a continuous buffer. In addition, since the 1970s, no coastline accretion has occurred, possibly due to sea level rise. Thus, low impacts storms are likely to now present a greater risk of significant impacts. This study is one of a suite of Historical Case Studies of Extreme Events conducted under Phase I of the NCCARF Synthesis and Integrative Research Program.