What are coastal hazards?

    When a natural process has the potential to negatively impact on things we value, we call it a hazard. Shoreline adaptation plans look at the impact of three coastal hazards: erosion, inundation, and rainfall flooding. The hazard modelling used to inform these plans takes into account how climate change will alter the frequency, magnitude and extent of these natural hazards.

    Why do we need to adapt?

    Global temperatures are rising due to greenhouse gas emissions, causing a range of impacts from higher sea levels to increasing rainfall intensity. The impact of climate change will depend strongly on the steps taken to mitigate carbon emissions in the near future. The Intergovernmental Panel on Climate Change (‘the IPCC’) has modelled a series of scenarios commonly referred to as ‘Representative Concentration Pathways’ (RCPs). The primary purpose of the RCPs is to provide projections of greenhouse gas concentrations which correspond to changing energy levels within the atmosphere. Each RCP has been correlated with increasing temperature and sea level rise.

    Representative Concentration Pathways showing how the pathways to reduce carbon emissions are linked to increases in (A) global average temperature and (b) global average sea level rise (Source: IPCC,2014 and MfE, 2017).


    What are Auckland Council owned land and assets?

    In many parts of the Auckland region, coastal land is publicly owned and managed by Auckland Council. This land includes all public beaches, esplanade reserves, and regional and local parks on or near the coast. Shoreline adaptation plans also look at all the assets within these areas that are provided to increase the accessibility and amenity of the coastline.

    How can we adapt the shoreline?

    Coastal areas are constantly impacted by natural processes such as erosion and storm events. Adapting the shoreline means we consider the risk of such events in our long term planning, by selecting appropriate management strategies. There are four major adaptation strategies that we can choose from:

    • No active intervention: let nature take its course
    • Limited intervention: maintain and support the existing coastal environment
    • Hold the line: fix the coastal edge at a specific location
    • Managed retreat: move assets out of hazardous areas