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1 Introduction

Flooding is a natural process, and in New Zealand this process can be dramatic. As a group of small islands in the ‘roaring forties’, weather patterns mean that we experience high-intensity rainfall regularly. On average a major flood occurs every eight months. Climate change is likely to increase both the intensity and likelihood of rain and flooding occurring in the future.

With over a hundred cities and towns located on flood plains, New Zealand has a long history of living with floods. Making decisions on how best to protect life and property from floods has been ongoing since settlement. The challenge New Zealand now faces is how best to reduce the damages and losses from flooding as part of our everyday living and working lives.

This report has been prepared by the Ministry for the Environment and the Flood Risk Management Review Steering Group and provides recommendations on how the management of flood risk can be improved in New Zealand. The views in this report do not necessarily represent the views of individual organisations represented on the Steering Group.

1.1 The Flood Risk Management Review

New Zealand suffered major flooding in 2004, affecting the lower North Island and the Bay of Plenty. The floods led to major regional social, economic and environmental disruption, requiring substantial relief from central government. Following these events the Flood Risk Management Review and work programme was agreed, and a Steering Group was established.

The work programme (see Appendix 1) sets out 36 questions on three key topic areas:

  • the role(s) of central government, local government and communities in ensuring good risk management practices are adopted in managing rivers and floods

  • funding and affordability, essentially asking who benefits, who pays, and who can afford flood risk mitigation

  • current flood risk management practices and whether these practices are appropriate, now and into the future, to meet the needs of New Zealanders.

The Flood Risk Management Review is now complete. The review focused on the processes, policies and institutional practices that influence flood risk management. In particular the review examined reduction and readiness, rather than the response and recovery aspects of flood risk management. The actual risk to each and every community within New Zealand was not examined.

The three key topic areas of roles, funding and practice are used to report the findings and recommendations of the Steering Group. A response to each of the questions in the work programme can be found in Appendix 2.

1.2 The Steering Group

The Flood Risk Management Review Steering Group’s role has been to:

  • provide strategic oversight of the review

  • ensure the policy and operational needs of central and local government were considered and addressed in the review work programme

  • make links with other policy initiatives across government, including resource management and climate change policy implementation

  • monitor the progress of the review and provide guidance, advice and direction to the programme manager and project team

  • ensure appropriate people within the Steering Group’s member organisations and sectors were informed of the work programme and review.

The Steering Group was convened in September 2004 and last met in July 2007. Membership of the Steering Group consisted of representatives from:

  • Ministry for the Environment (Chair)

  • Department of the Prime Minister and Cabinet

  • Ministry of Civil Defence and Emergency Management

  • Department of Internal Affairs

  • Ministry of Agriculture and Forestry

  • Treasury

  • regional councils

  • territorial authorities.

1.3 What is flood risk management?

Flood risk is a combination of the likelihood of a flood and the consequences (or effects) of that flood. A flood’s consequences depend on how many people and assets are exposed to a flood, and how vulnerable those people and assets are to the flood. If the size or frequency of a flood increases, or the effects of a flood increase, then so too does the risk.

Weather systems, land forms, water courses, people, development and economic activity all determine flood risk. Ideally, flood risk management is responsive to local conditions, based on good information and sound decision-making by an informed community aware of the risks.

Comprehensive flood risk management, along with other hazard risk management approaches, encompasses the 4 Rs: reduction, readiness, response and recovery. Good flood risk management requires actions across the 4 Rs to be integrated to achieve the desired goal.

Flood risk management practices rarely eliminate the flood risk, but they may treat a significant component of the risk. Flooding that occurs beyond this treated component is called 'residual risk'. Where reduction and readiness fail to prevent losses during a flood, an emergency management response and post-flood recovery activities are required.

Management options to reduce flood risk include:

  • structural measures, including stopbanks, groynes and other tools that seek to control rivers and flooding (keeping flooding away from people)

  • policy and planning measures that seek to control land use and activities in areas that are subject to or contribute to flooding (keeping people away from flooding)

  • emergency management planning to enable communities to respond to and recover from flooding effectively and efficiently

  • designing and flood-proofing assets to withstand flooding (living with flooding).

Often a mixture of options is used to manage flood risk in an area. This means using measures to control flooding, as well as managing people and assets to reduce a community’s vulnerability to flooding. Decisions are often made within a political environment that seeks to balance competing needs and resources. The decisions made can affect the flood risk management outcomes in a number of ways.

To meet the challenge of future flooding and decrease the flood risk to New Zealand, the factors driving flood risk outcomes need to be addressed. The actions suggested in this report address the drivers below by improving current levels of information, guidance, resources and support, and by suggesting that the goal of reducing flood risk be adopted nationally.


Drivers of flood risk management

vers of Flood Risk Management

This image presents the drivers of flood risk management in a cyclical format.

Drivers against good flood risk management

  • Lack of capacity, resources & good information
  • Vested interests
  • Inertia & inability to change
  • Bias towards status quo
  • Unwillingness to pay
  • Not bearing the full cost of decisions

The drivers against good flood risk management lead to increased flood risk:

Increased flood risk

  • Economic – urban and rural development at risk, financial cost of flooding underestimated, under-insurance
  • Social and cultural – People and assets not sufficiently protected, flood management excluded from community needs, legacy of past decisions not reviewed, hazard control and over-reliance on engineering
  • Political – Short-term outcomes, Desire for short-term visible actions & achievable goals, Enabling legislation with no explicit goals
  • Environmental – Natural processes not understood or taken into account, Probability of large floods not understood, Climate change & variability not factored in

Drivers for good flood risk management

  • Political will & agreed goal of risk reduction
  • Resources
  • Guidance
  • Government policies & legislative framework to support risk management
  • Good information available
  • Monitoring and evaluation
  • National capacity in allied fields

The drivers for good flood risk management lead to decreased flood risk:

Decreased flood risk

  • Economic – Sustainable flood plain development, Risk management as a normal part of business, Insurance
  • Social and cultural - people understand & accept level of flood risk, Equity, across NZ & intergenerationally, Risk management includes the 4 Rs & residual risk, Non-structural, structural & emergency management measures
  • Political – Common long-term goal, Long-term outcomes, Agreed roles and responsibilities, Adaptive & responsive to change
  • Environmental – Integrated catchment management, Protecting life-supporting capacities and ecological values, Working with natural processes & systems, Climate change