ECM_22343537_v1_Coastal Hazard Assessment · 132000.200173.1

                                                               Internal use only




              5           Coastal Processes
              The coastal processes of interest to this investigation are water levels (including sea level rise
              predictions), wave conditions, and sediment transport processes.

              5.1         Tides and Storm Tide
              The water levels of interest for a reassessment of the erosion prone area include the astronomical tide,
              storm tide and the predicted rise in mean sea level associated with climate change. The following
              sections describe the water levels adopted for the assessment.

              5.1.1       Astronomical Tides
              Sunshine Beach experiences semi-diurnal tides with a tidal range of 1.4 metres at spring tides. Table 1
              presents the published tidal planes for Noosa Head (Maritime Safety Queensland, 2023) which are
              considered consistent with conditions at Sunshine Beach, due to the proximity.
              Table 1 Noosa Head Tidal Planes (Maritime Safety Queensland, 2023)


                                                                        Water Level    Water Level
                                           Tidal Plane
                                                                       (m above LAT)     (m AHD)

                                           Highest Astronomical Tide        2.28          1.157

                                           Mean High Water Spring           1.78          0.657

                                           Mean High Water Neap             1.45          0.327

                                           Mean Sea Level                   1.06          -0.063

                                           Mean Low Water Neap              0.71          -0.413

                                           Mean Low Water Spring            0.38          -0.743

                                           Lowest Astronomical Tide           -           -1.123


              5.1.2       Sea Level Rise
              The effects of climate change associated with emission of greenhouse gases has caused a rise in mean
              sea level above pre-industrial levels, and sea levels are predicted to continue to rise into the future. The
              Queensland Government has adopted a predicted sea level rise of 0.8 metres by the year 2100 above
              present day mean sea level. It is noted that BMT (2018) adopted the following sea level rise allowances
              (above present day mean sea level) as part of phase 3 of the Coastal Hazard Adaptation Strategy
              (CHAS):
                       0.2 metres by 2040,
                       0.5 metres by 2070, and
                       0.8 metres by 2100.

              The adopted sea level rise allowances are consistent with industry practice and will be used for this
              assessment.




              13 February 2023         2 ARAKOON CRESCENT, SUNSHINE BEACH                             PA3303       20


Document Set ID: 22343537
Version: 1, Version Date: 16/03/2023