Mr Dan Rodger1, Mr Michael Thomson1
1Jbpacific, Brisbane, Australia
Many of Australia’s coastlines are under threat of erosion, tidal inundation and flooding, which will be worsened by increased sea levels. The management response is typically delivered through a Council-led management plan, such as a Coastline Management Plan (CMP) or Shoreline Erosion Management Plan (SEMP). These evaluate local coastal processes, identify coastal erosion and flooding issues, and evaluate options for future management – through planning, response, mitigation or adaptation. However, when considering mitigation approaches, due to challenges in quantifying the performance of nature-based options many plans have a reliance on hard structures, either seawalls, breakwaters or groynes.
Advances in numerical modelling now allow nature-based systems to be evaluated for local conditions, with their performance in mitigating erosion or flooding quantified. This presentation describes the modelling being used to evaluate the effectiveness of vegetated dunes, mangroves, log-catchers, sand nourishment, and even vegetated geo-bag seawalls, so that they can be included within ongoing management plans. Through models such as XBeach, options such as dune restoration can be shown to mitigate erosion by up to 15%. This is used within economic and cost-benefit analysis, and will support the adoption of nature-based approaches within management plans, and to attract subsequent funding for future works.
Dan is Director with JBPacific who specialises in building community resilience to natural disasters. He is a chartered coastal engineer, flood engineer, numerical modeller and forecasting specialist with 13 years experience working across Australia and internationally.