Coastal Restoration Trust of New Zealand

Coastal Dune Ecosystem Reference Database

Clifton to Tangoio Coastal Hazards Strategy 2120, Hawke’s Bay, New Zealand. Book

Journal / Source
Responding to rising seas: OECD country approaches to tackling coastal risks
Publisher / Organisation
Chapter 6
sea level, climate change
New Zealand has one of the longest coastlines in the OCED and one of the smallest populations. This, along with its varied landscape, makes developing adaptation responses challenging, particularly when considering how the costs of those responses will be met. As an island nation, New Zealand has strong social and cultural connection with its coastline, and it provides unique habitats for indigenous fauna and flora. It is also the focus of much economic activity. Today around 65% of the population and major infrastructure are located within 5 km of the coast. Climate change poses an increasing risk to these important coastal areas, in particular because sea-level rise (SLR) increases exposure to coastal hazards. This exposure is exacerbated by ongoing coastal development and rising property values. Over the last 100 years, the sea level around New Zealand has risen at an average rate of 1.8 mm per year. As New Zealand is geologically active, rising sea levels are also exacerbated by tectonic effects of uplift and subsidence. Global projections estimate further rises by 0.2-0.4 m by 2060 and 0.3-1.0 m by 2100. The levels of risk exposure in different regions in New Zealand are illustrated in Figure 6.2. Using a combination of population and infrastructure measures, the highest coastal risk exposure is in the Hawke’s Bay and Canterbury regions. Sea-level rise is, however, only part of the picture. Climate change is also expected to affect New Zealand’s coastal areas through increased coastal erosion; more frequent and extensive coastal flooding; higher storm surges; saltwater intrusion into coastal aquifers and further inland in estuaries; and changes in surface water quality, groundwater characteristics and sedimentation. Risks to the coastline from a range of these impacts and the responses that are needed will be specific to each local area.