Coastal Hazard Risk Assessment

Oct 31, 2024
1 min read

Updated: Aug 17, 2025

Dr de Lange of Waikato University delivers a coastal hazard risk assessment in accordance with the requirements of the New Zealand Coastal Policy Statement 2010.

Thank you to all CRU members for contributing to the fundraising that enabled the study to be commissioned. Whereas the KCDC commissioned Jacobs 'Sustainability and Vulnerability' reports which flagged an estimated 7000-10000 properties as being subject to coastal hazards (i.e., mapped by Jacobs to be within a 'Coastal Adaptation Area); the de Lange study finds less than 500 properties at risk of erosion over the next 20 years – noting that predictions beyond a 20-year timeframe are found to be no more reliable than tossing a coin.

In terms of hazard risk assessment, de Lange finds erosion and inundation of the coastal reserve arising from climate change-induced sea-level rise over a 100-year timeframe to be improbable and impossible to reliably predict. He finds that the Kāpiti coast is generally an accreting coast and that in order to better monitor the on-going sediment supply, the KCDC install a number of new instrumental monitoring techniques to implement a scientifically robust adaptive planning regime.