2023 NZPI CONFERENCE PRESENTATION


Understanding Managed Retreat

Moving climate adaptation from the 'too hard basket' to 'we've got this'.


PRESENTED BY: Chris Cameron & Dr Lisa Marquardt



Managed retreat involves relocation from a high-risk origin location to a low-risk destination area. A major problem with pre-emptive managed retreat is a lack of real-world experience. The contrast with engineered responses couldn't be starker. For built/protective responses we apply engineering expertise that has developed over several hundred years. This allows for detailed options to be assessed, and for costings to be estimated. Meanwhile, for managed retreat there are no established methods for undertaking cost assessments - even simple estimates. The reality is that managed retreat will involve both planning and engineering. For decision-makers to make informed decisions, there is an urgent need for costings for managed retreat. This will enable 'apples with apples' comparisons between protection and managed retreat and enable discussions with the wider community on what may be realistic, affordable, and desired. The first step for a managed retreat involves identifying an area where the risk of remaining is likely to be unacceptably high, either now or in the future. These areas are known as an 'origin area', and there are several complex considerations for such areas, including: preventing continued development; considering compensation for those affected; removing elements at risk; reinstating new land-use activities; improving the area. To carry out a managed retreat, the 'destination area(s)' also need to be identified. These should be low-risk areas - either greenfields or brownfields - where new development or intensification can occur. For destination areas, there are also a number of factors to consider: the identification and acquisition of appropriate areas; design (preferably co-design) of a new and attractive offering; on-site development; delivery.