Coastal Hazard Assessment · MCU25/0087

                                                 17 The Esplanade, Sunshine Beach                              Report



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

4.1       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.
4.1.1     Astronomical Tides
Sunshine Beach experiences semi-diurnal tides with a tidal range of 1.4m at spring tides. Table 4-1
presents the published tidal planes for Noosa Head (Maritime Safety Queensland, 2024) which are
considered consistent with conditions at Sunshine Beach, due to the proximity.
Table 4-1 Noosa Head Tidal Planes (Maritime Safety Queensland, 2025)
 Tidal Plane                       Water Level                  Water Level
                                 (m above LAT)                    (m AHD)
 Highest Astronomical Tide            2.35                          1.23
 Mean High Water Spring               1.85                          0.66
 Mean High Water Neap                 1.52                          0.33
 Mean Sea Level                       1.15                         -0.06
 Mean Low Water Neap                  0.79                         -0.41
 Mean Low Water Spring                0.45                         -0.74
 Lowest Astronomical Tide               -                          -1.12


4.1.2     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 0.8m 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):

        0.2m by 2040;
        0.5m by 2070; and,
        0.8m by 2100.

The adopted sea level rise allowances are consistent with industry practice and will be used for this
assessment.
4.1.3     Storm Tide
Storm tide is the total water level associated with the combination of the normal astronomical tide and
the tidal surge from a storm event (e.g. tropical cyclone). There have been several previous storm tide
studies undertaken for the Sunshine Coast with the most recent being the ‘Sunshine Coast Storm
Tide Study’ (Aurecon, 2013). The design storm tide levels determined by (Aurecon, 2013) for the 100,
500 and 1000-year ARI events are presented in Table 4-2.
Noosa Shire Council has undertaken a broad-scale reassessment of coastal hazards from Peregian
Beach to Teewah Beach as part of the ‘Noosa Shire Council Coastal Hazards Risk, Vulnerability and
Adaptation Assessment’ (BMT, 2018).
As discussed in the introduction, a 100-year ARI storm tide level has been adopted for this
assessment, discussed further in Section 5.2.2.




                                                                     252662-MN-RP-CO-0001B | 10 November 2025 | Page 18