PA3660-Coastal Hazard Assessment - 4 arakoon

                                                 Project related




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 5-2.

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). The 100-year ARI storm tide level of 1.74m AHD was adopted by
BMT (2018) for the reassessment of the erosion prone area width at Sunshine Beach.

To address the SDAP (Performance Outcome 6 of State Code 8) outlined in Section 4.1 the vulnerability
of the proposed property and house to an extreme storm events has been considered and assessed. As
discussed in the introduction, a 100-year ARI storm tide level has been adopted for the extreme analysis.
The extreme event assessment is discussed further in Section 6.2.2.


Table 5-2 Adopted Storm Tide Levels for Sunshine Beach (Aurecon, 2013)
                                     Current Climate                                                Current Climate
        Return Period                                                Wave setup
                                     Storm Tide Level                                              Storm Tide Level
          (years ARI)                                                    (m)
                                        (m AHD)                                             Inclusive of wave setup (m AHD)

                100                       1.74                           0.87                            2.61

                500                       1.84                           1.17                            3.01

                1000                      1.89                           1.26                            3.15


For planning purposes, the current climate storm tide level inclusive of wave setup is used to define
inundation hazard. To calculate short-term erosion the current climate storm tide level is taken exclusive of
wave setup (refer to Section 6.2.2 for calculation of short-term erosion).

5.2             Wave Climate
The wave climate at Sunshine Beach is influenced by both locally wind-generated sea and ocean swell.
Sea describes wind generated waves where wind energy is still being transferred to the ocean. Swell
describes wind generated waves that have travelled out of their generating area. Swell characteristically
exhibits smoother, more regular, and uniform crests and a longer period than sea. In open coastal areas
sea waves generated by local winds are often superimposed on swell waves.

The wave climate for Sunshine Beach has been previously reported by BMT (2013), ‘Coastal Processes
Study for the Sunshine Coast’ prepared for the Sunshine Coast Regional Council. Wave roses shown by
BMT WBM (2013) indicate that the wave climate for Sunshine Beach is dominated by waves from the
east-southeast direction (refer Figure 5-1).

The design offshore significant wave heights for the Sunshine Coast have been previously published by
BMT (2013), refer Figure 5-2. For this assessment a 100-year ARI offshore significant wave height of 6.2
metres has been adopted to be consistent with the ‘Coastal Processes Study for the Sunshine Coast’
prepared by BMT (2013).




11 April 2024           4-6 ARAKOON CRESCENT, SUNSHINE BEACH                    PA3660-RHD-XX-ZZ-RP-Z-0001       21