Abstract
The flood hazard in established urban areas is increasing. This is due to the effects of anthropogenic modification of catchments and rivers, and an increase in climatic extremes caused by global climate change, which result in an increase of the occurrence and magnitude of flooding, and the establishment of the 'catastrophe potential' cycle, which creates an increasingly vulnerable society.
The main research problem of this study is the adequacy of processes provided by the natural hazards legislation with which local authorities can respond to increased flooding risks in established urban areas. Specific objectives are: to explore potential conflicts between existing use rights under the Resource Management Act and planning for an increasing flood risk; to assess the natural hazards management framework in relation to responding to an increasing natural hazard; and to develop recommendations by which local government authorities can respond to increased flood hazards.
The approach to the problem involves a discussion of flood hazard management techniques, a review of the natural hazards management legislation in New Zealand, and a case study of local government response to the increased flood risk in Alexandra, Central Otago.
This research reveals a number of significant issues concerning the hazard management process in Alexandra, and implications for other situations. These are the effectiveness of relevant legislation, liability issues, the relationship between different levels of local government, perception of the flood hazard, the physical response to flooding in Alexandra, and the difficulties of responding proactively to increased flood hazards.
From this, many impediments to a proactive response by a local authority to an increased flood hazard have been identified. These include problems with the perception of the increase, defensibility of technical predictions, community inertia to change, and a lack of resources.
Recommendations include the provision of national direction in addressing this issue, amendment of the legislation to allow greater powers of response to local authorities, the provision of funding, and the formation of legislation concerning the effects of large dams. There is also a need for a formal mechanism to require joint hazard plans between regional and district councils to prevent the formation of a gap in natural hazards management, and a tightening of hazard avoidance legislation. Requirements for the development of community based responses to increased flood hazards are identified.