How sea level rise impacts coastal development

Sea levels around the world are rising as a consequence of climate change and increasing global temperatures. Modelling by the Inter-governmental Panel on Climate Change (IPCC) found that average global sea level has been rising over recent decades at a rate of approximately 3.3 millimetres per year.

Though the effects of sea level rise along the coast are gradual, they are significant over the long term. We can expect greater erosion of dunes and loss of beaches, increasing shoreline erosion at many locations. 

Sea level rise can also change the angle at which waves strike the shore, leading to changes in rates of littoral sand drift and the locations at which beaches build up or erode.

Sea level rise can also affect the size of areas flooded and increase the frequency of widespread flooding.  This will not only have impacts on infrastructure and development, but also the location and species mix of coastal ecosystems and habitats.

In recognition of this situation and to minimise future risks to developments, the Coast Protection Board proposed that a sea level rise of 0.3m by the year 2050 be adopted for most coastal planning and design.

A number of standards now exist that require development to be safe from the effects of a 0.3m sea level rise and to be capable of being protected against additional flooding and/or recession due to a further 0.7m of rise (view the policy document).