RFI - PA2906-Coastal Hazard Assessment-R2 · MCU21/0212

                                              Internal use only




         10 years of such a planning period, there is only a 10% probability of occurrence
         of the design storm. Thus, the risk of a storm breaching the entire erosion prone
         area at some time during the 100-year period will be significantly less than 63%.”

BMT (2018) adopted a combination of a 100-year ARI Storm Tide level and 100-year ARI significant wave
height as the design storm event for the reassessment of erosion prone areas with Noosa Shire Council.
It should be noted that the joint probability of a combined 100-year ARI storm tide and 100-year ARI
significant wave height is likely to greater than a 100-year ARI storm event. This combination of design
storm tide level and wave height will be adopted for the site-specific reassessment of the erosion prone
area reported herein.

An additional assessment of short-term erosion will be undertaken for a more extreme event to assess the
vulnerability of the proposed house and pool to assist with foundation design. The design parameters for
the assessment of the short-term beach erosion and scenarios are presented in Table 4.
Table 4 Design Storm Events for Short-term Beach Erosion Assessment


                                                                      Storm Event
                         Storm Component
                                                          100-year ARI      Extreme Event
                         Significant Wave Height               6.2m               6.2m
                         Storm Tide                        1.74m AHD          1.84m AHD
                         Sea Level Rise                          -                0.8m

Figure 18 and Table 5 present the results of the modelled storm erosion associated with the above 100-
year ARI design storm event. This shows storm erosion of 51 metres measured from HAT position on the
current beach profile (pre-storm profile) to the toe of the erosion scarp.

The extreme event scenario adopted in Table 4 incorporates the impact associated with a 0.8m increase
in mean sea level in addition to a 500 year ARI storm tide event (i.e. 1.84m AHD). This provides for a total
water level of 2.64m AHD for this assessment and therefore incorporates additional erosion associated
with the adopted sea level rise projection. This allowance for sea level rise is consistent with the
Queensland Government policy for the planning period to 2100.




15 October 2021     66 SEAVIEW TERRACE, SUNSHINE BEACH                     PA2906-RHD-ZZ-XX-RP-Z-0001   26