2021-01-18 GC - Item 3 - Attachment 3 - Cost Benefit Analysis for Coastal Erosion Options

4.          Description of costs and benefits

The costs and benefits for each project option have been identified through consultation with Council
and BMT. The costs of coastal protection measures have been provided by BMT as part of their
technical assessment of the coastal adaptation options. The values used to quantify the benefits have
been carefully selected using both desktop review of the literature and stakeholder consultation.
Aither’s extensive experience in economic analysis and coastal adaptation has been used to assess
the reliability and relevance of data, in particular where data specific to the Noosa region is not
available. The majority of values used are either directly taken from data relating to Noosa Local
Government Area (LGA) (for example data provided by Noosa Council and tourism data) or to other
locations in Queensland or New South Wales that share similar characteristics (for example
recreational beach use).

All data and assumptions used in the analysis have been provided in Appendix B.



4.1.        Costs
The management costs included in the CBA are set out in Table 2. These costs have been provided
by BMT and include high-level assessments of the potential costs of undertaking relevant coastal
adaptation management activities. The administrative costs of planning changes or acquisitions have
not been included in the analysis at this point due to limited data.

Table 2        Costs of management activities

 Type                         Description                             Value                   Source

                              Revegetation and maintenance over a
 Dune management              5-year life including weed and vermin   $1100/ha                BMT
                              control and monitoring

                              Sand supply and placement, all
                              beaches using offshore sand source.
 Dune augmentation            Assumes placing on beach and using      $63/m3                  BMT
                              conventional earthmoving equipment
                              to shape beach and dunes.

                              Costs include design and construction   $15,000/m upfront and
 Seawall                                                                                      BMT
                              for rubble mound structure.             $40/m/year ongoing


As well as the management costs associated with physical (i.e. on-ground) works, for each coastal
hazard adaptation option shown in Table 2, there are ongoing costs to property owners in relation to
the maintenance and redevelopment of their properties. These costs are incurred under the base
case but change under the different options, and therefore need to be included in the analysis.
Redevelopment costs were estimated based on building approvals data provided by Noosa Council,
and an assumed rebuild interval of 20 years.




AITHER | Final Report                                                                                  12
Noosa Shire Council – Coastal Hazard Adaptation Plan