Report: TR 2006/48

Author: Christopher Turbott, Andrew Stewart

Abstract

There are substantial areas of existing development at risk from coastal hazards in the Auckland, Waikato and Bay of Plenty regions.

Communities have two basic alternative choices for management of the hazard. These are to: 

• adopt a strategy of holding the line of the shore, which involves management of natural coastal processes, or
• adopt a strategy of retreat from the hazard, which involves managing development.

Holding the line of the shore has been the generally preferred approach over at least the last century. However, it is increasingly questioned because of the high ongoing cost, the adverse effects of protection works on beach systems, and the uncertain feasibility of maintaining protection works over large areas of retreating shoreline in the long-term. Consequently, the second strategy of retreat is receiving increasing attention with an emphasis on a managed process of retreat; i.e. “managed retreat”.

However, managed retreat is not well understood in the New Zealand context. This report characterises managed retreat and reviews the main options available for implementation.

The report found that managed retreat would need to be implemented as a long-term strategy. It may take several generations for it to become accepted as a normal response to coastal hazards. Councils would need to comprehensively integrate managed retreat strategies into long-term urban growth, infrastructure and reserves planning, as well as regulatory planning.

Note: Partial funding and support was provided by: the Auckland Regional Council, Environment Bay of Plenty and the Thames Coromandel District Council

Managed Retreat from Coastal Hazards: Options for Implementation [PDF, 1.1 MB]