Coastal Restoration Trust of New Zealand

Coastal Dune Ecosystem Reference Database

Defining coastal hazard zones for setback lines. A guide to good practice. Technical Report

Ramsay, D.L., Gibberd, B., Dahm, J., Bell, R.G.
Journal / Source
National Institute of Water & Atmospheric Research Ltd
This best-practice guide has been developed to assist Local Authorities make sustainablybased decisions for the avoidance or mitigation of coastal hazard risks within their coastal land-use planning and development decision-making. The guide focusses on approaches to defining present and future coastal hazard exposure as an input to development setbacks to manage risk from coastal-related hazards and the effects of climate change. The guide has been written to aid technical staff from Regional or Unitary Councils, coastal Territorial Authorities, and coastal hazard practitioners. It is designed to complement the Ministry for the Environment guidance manual Coastal hazards and climate change: A guidance manual for local government (Ministry for the Environment, 2008) in encouraging a risk management approach by Local Authorities in ensuring that coastal hazards, and the impacts of climate change on these coastal hazards, are appropriately taken in to account in policy, planning and resource consent decision-making. The basic rationale applied within this guide is that Coastal hazard zones should more effectively encapsulate and present the inherent uncertainties to better inform development setback lines based on acceptable and appropriate levels of risk. The guide promotes a framework to enable increased robustness and accounting of uncertainties within coastal hazard assessments and associated development setbacks. Whilst the guide is not designed to be prescriptive on the methods used to define areas of coastal margins at risk from coastal hazards, it aims to build on the current deterministic approaches commonly used in New Zealand and the expertise and experience held by practitioners, to determine future coastal change, but to better characterise uncertainty by applying it within a pragmatic probabilistic way. This would improve the baseline information for incorporation of risk-based considerations within coastal land-use planning and development decision-making.