2021-01-18 GC - Item 3 - Attachment 2 - Phase 7 Project Summary Coastal Hazards Adaptation Plan

Noosa Shire Council Coastal Hazard Adaptation Plan: Project Summary                                       33
Conclusions and Recommendations




         Locality               Recommended Adaptation Options                    Recommended Adaptation
                                                                                  Hierarchy Approach
         Noosa North Shore      Design of hazard resilient infrastructure         Avoid/Prepare
                                Reduce intensity of future development
         Lake Cootharaba        Design of hazard resilient infrastructure         Prepare
                                Relocate important infrastructure
                                Land management to support habitat migration

        The feedback received during public consultation throughout the project thus far has been for Council
        to focus on less intrusive solutions to minimising these potential risks such as nature-based solutions
        (i.e. beach management and dune augmentation) on the open coast, rather than hard (less
        reversible) interventions such as seawalls or levees. This was borne out by both the options
        assessment (Phase 6) and more detailed Cost-Benefit Analysis (Phase 7). particularly for the open
        coast areas which favoured ‘lighter touch’ options. For the settlement of Teewah, on the coast north
        of Noosa, a planned transition was favoured by the CBA. Where inundation from sea level rise or
        stormtide is the predominant hazard, the Cost-Benefit Analysis has favoured intervention such as
        the construction of levees or infrastructure upgrades where there is significant public infrastructure
        and properties at risk. The probable timing for these interventions is for adaptation options to be in
        place by 2070. The study also found that planning controls may also be used to support nature-
        based solutions, and thus could be included in a suite of complementary measures that are
        consistent with the feedback received.

4.1     Additional considerations
        While natural options such as dune augmentation and beach nourishment ranked highly in open
        coast areas, uncertainty remains as to the most economical and reliable sources of sand that can be
        used for this purpose. It is strongly recommended that investigations into possible sand sources for
        these purposes are undertaken in the near future, with a view to securing long-term access, statutory
        approvals and funding for implementation and a clear and sequenced action plan. This is especially
        important given there may be a need to address the impacts of erosion promptly following extreme
        storm events.

        The concept design for inundation protection measures i.e. levees should also be further developed
        to gain a deeper understanding of design options and costs.