2021-01-18 GC - Item 3 - Attachment 1 - Coastal Hazards Adaptation Plan for Community Consultation

                                              Reference Box #4

                                   Understanding ‘cost-benefit analysis’


 A cost benefit analysis is a method by which organizations can analyse and compare competing
 investment opportunities or decisions.

 To do this, a model is built that incorporates the benefits of a particular action (e.g. investing in specific
 adaptation measure), as well as the associated costs, and subtracts the costs from the benefits. When
 completed, a cost benefit analysis will yield results that can be used to inform reasonable decisions
 regarding the feasibility of a particular course of action.

 Organizations rely on cost benefit analysis to support decision making because it provides an objective,
 evidence-based view of the issue being evaluated—without the influences of opinion, politics, or bias. By
 providing an unclouded view of the consequences of a decision, cost benefit analysis is an invaluable tool
 for councils allocating significant resources, making decisions that have significant consequences, and
 creating long-term plans.

 The cost-benefit analyses performed as part of the CHAP’s development have been done in alignment
 with the requirements prescribed under the QCoast2100 program.




The analysis of adaptation options completed as part of Phases 6 and 7 revealed a common set of
preferred adaptation measures across localities with similar risks, as well as those that would not
be feasible or considered unsuitable for the Noosa coastal zone.


Options for responding to coastal erosion risks
Beach conditions naturally change over time as a result of various tide, waves and wind conditions
combining to erode and replenish sand.

However, due to sea level rise a trend of continuous, gradual erosion of sand from the beach
resulting in long-term shoreline recession is expected. Development and other disturbance of the
natural dune system by human activities increases the erosion potential by interrupting the natural
beach and coastal processes of erosion and sand replenishment. Therefore, eroded coastlines will
increasingly fail to rebuild fully following extreme events, increasingly the likelihood of permanent
loss of beach areas and dunes if appropriate adaptation measures are not undertaken.

Decisions made today may have ramifications for several decades or more, depending on the
asset type and the life of the asset, or the adaptation measure pursued. For example, a house built
today is likely to still be in place in as much as 40 years’ time, with some modifications. A public
amenities block or picnic facilities may have an asset life of just 10 years until renewal is
considered. Therefore, consideration of short, medium, and long-term timeframes (i.e. as far as the
years 2070 and 2100) is important when assessing appropriate response to coastal erosion risks.

Local government has a responsibility to make well considered decisions and land use policy that
takes account of longer time horizons using the best information available at the time and to review
this as more information develops. Early planning and taking an adaptable and proactive approach


Noosa Council – Coastal Hazards Adaptation Plan 2020 - 2030 (community consultation version)             Page 24