2019-12-16 General Committee Agenda

GENERAL COMMITTEE MEETING AGENDA                                                          16 DECEMBER 2019


    Multi-criteria analysis including a detailed risk assessment (Section 4.3 and Appendix D).
    Delivery of a Shoreline Erosion Management Plan (Section 5).

3.    Proposed Implementation Pathway

The proposed implementation pathway for erosion management has been separated into three
zones, with two “trigger lines” for intervention. These zones are shown below, in Figure 1, with
the trigger lines forming the boundaries between the coloured zones. The first trigger line was
established based on the 2016 shoreline position, before erosion accelerated, and allows a
limited recreational beach and a suitable sand buffer for the protection or reestablishment of
vegetation. The second trigger line is the minimum width of the Noosa Spit within which a seawall
may be constructed.

The proposed pathway is intended to maintain the beach width in the green zone below for as
long as feasible and delay, as long as possible, the need for a structural sea wall at the edge of
the red zone.




Figure 1: Proposed trigger zones. Image above is pre-erosion (2016) and image below is current day.

As such, the Noosa Spit SEMP proposes a two-staged intervention pathway consisting of:
1.   Beach nourishment undertaken in conjunction with creating a sand plug at either end of the
     Doggie Beach, as shown in Figure 2. The beach nourishment would be monitored and
     evaluated with respect to the trigger lines shown in Figure 1 and repeated when the
     shoreline eroded into the yellow zone. While it is difficult to estimate the exact time
     between nourishment programs, based on previous attempts to do this, it is expected that
     this may last 5-8 years.
2.   If beach nourishment becomes ineffective/unfeasible a seawall could be constructed in the
     approximate alignment of the red section in Figure 1. This could then be covered with sand
     if deemed appropriate.



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