MCU25 0087 - Reference Document - Coastal Hazard Assessment (As Published)

                                                                           17 The Esplanade, Sunshine Beach                              Report


                      height at this specific location. The assessment employed an iterative methodology to determine the
                      dune height, involving an initial calculation of S using a test dune height. Subsequently, D was
                      calculated based on S, C, and NxR to assess if the active profile (horizontal distance from NxR+C+S)
                      intersected the profile at the same dune height utilised in the S calculation. If there was a disparity, S
                      was recalculated with different dune heights until it aligned with the dune height of the active profile.
                      For this evaluation, a dune height of 15m was established (Figure 5-8).




                                                 Figure 5-8 Dune slumping for 100-year ARI scenario for 17 The Esplanade

                      5.2.5      Summary of the Erosion Prone Area Reassessment
                      The erosion prone area reassessment for this site has been undertaken in accordance with the
                      (Department of Environment and Heritage Protection, 2013) requirements with a planning period of
                      100 years to accommodate the asset lifespan of the proposed house. We have considered the effect
                      of beach erosion associated with a 100-year ARI storm event.
                      The site-specific erosion prone area calculated for the site is 82.5 metres. Rounding up to the nearest
                      5, the erosion-prone distance was adjusted to 85 metres, measured from the seaward toe of the
                      frontal dune (2.3 metres AHD). It is worth mentioning that with the additional 3 metres, the factor of
                      safety increases from 40% to 45%. The components of the erosion prone area for 17 The esplanade,
                      Sunshine Beach are presented in Table 5-5 and the spatial extents are shown in
                      Table 5-5 Reassessed Erosion Prone Area for 17 The Esplanade, Sunshine Beach
                        Erosion Prone Area Component                      100-year ARI
                        Long-term Erosion (m)                                 10
                        Short-term Erosion (m)                                17
                        Recession due to 0.8m SLR (m)                         16
                        Safety Factor                                         1.4
                        Dune scarp slumping (m)                               25
                        Erosion prone area Width (m)                          85




                                                                                               252662-MN-RP-CO-0001B | 10 November 2025 | Page 29

Document Set ID: 24631530
Version: 1, Version Date: 24/03/2026