Extreme sea-level rise and adaptation options for coastal resort cities: a qualitative assessment from the Gold Coast, Australia

The Gold Coast, Australia is a coastal resort city whose urban environment has evolved through a series of human interventions on the natural shoreline. Such cities rely on a perceived high quality environment which in turn is reliant on continuing maintenance (e.g. beach nourishment, inlet dredging, drainage). Climate change consequently holds particular challenges for coastal resort cities. Sea-level rise impacts are likely to be manifest in increased frequency of flooding and beach erosion episodes. Here we consider adaptation options for the city under various future sea-level rise (SLR) scenarios at the high end of current predictions for the next century (þ1 m, þ2 m and þ5 m) with the proviso that the beach and waterways must be preserved to enable the city to continue to exist as a resort.We conclude that pre-planned adaptation would probably enable the city to survive SLR of 1 m. An unplanned response to the same SLR would likely be characterised by periodic crises, growing uncertainty and public unease and would have marginal chances of success. For a 2 m SLR we contend that even with an adaptation plan in place, the scale of measures required would severely stretch the city’s resources. Under a 5 m SLR over the next century we do not believe that any amount of planning would enable the city to survive as a coastal resort. Any adaptation to SLR would involve increased cost to maintain the artificial coastal environment.Adaptation options are particularly constrained by the widespread development around the waterways of the back-barrier area. Unlike other coastal cities, resorts depend on a public perception of a high quality environment. Maintaining this perception under SLR imposes particular adaptation constraints on resort cities.