Flood risk management review

This page provides information on the 2007 review of how New Zealand manages its flood risk and river control. 

The Ministry for the Environment led a two-year review of how New Zealand manages its flood risk and river control. This was completed in June 2007. A report has been published presenting the findings of the review:

The Ministry worked closely with local government and other government agencies on the review, including the Ministry of Civil Defence and Emergency Management, Ministry of Agriculture and Forestry (now Ministry of Primary Industries), Department of Internal Affairs, and the Department of the Prime Minister and Cabinet.

The review found that central government needs to strengthen the current policy framework and provide better guidance on flood risk assessment and good practice. 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.  

Background to the review

Over 100 New Zealand cities and towns, along with some of our most productive farmland, are located on floodplains. The review looked at what was being done to manage flood risk and where there were any problems.

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.

Flood risk management review: work programme

The flood risk management review work programme was grouped into the seven work streams listed below. Fore each work stream, a brief description of the main issue/s and the key questions addressed is included.

Adequacy of the current approach to flood risk management


Standards of protection against flooding may not be sufficiently high enough in many communities.

Key questions this work stream addressed:

  • What are the current levels of protection against flooding for New Zealand communities, and for rural land?
  • Are those current levels of protection suitable for New Zealand?
  • To what extent do current practices deal with possible very large and damaging flood events?
  • Are current flood protection assets being appropriately maintained by regional authorities?

Understanding current and future flood risk and what mitigation is required


  • Standards for river protection works are based on historical data, which in some cases is outdated and short and may not be appropriate in a time of changing land use and climate.
  • Present weather, rainfall and river level recording systems could be improved.
  • There is a need to ensure that science programmes are meeting current needs and will meet future needs.

Key questions this work stream addressed:

  • What is the flood risk in our regions given the likely consequences of landuse and climate change especially in light of the short hydrologic records that are common in New Zealand?
  • To what extent do current works and other methods mitigate that risk?
  • What extra mitigation measures might be needed, and at what time?
  • How will any such additional mitigation measures be funded?
  • How can present monitoring, forecasting and warning systems be improved cost effectively?
  • Are the science needs of flood management practitioners being met by current science programmes?
  • How good is the communication between the science community, flood management practitioners, and decision-makers?

Future best practice in flood risk management


Current river management practice is highly reliant on physical works, and this may not be the most appropriate approach to mitigate flood risks in the future.

Key questions this work stream addressed:

  • To what extent are present catchment management and land management practices mitigating or exacerbating flood risk (and fiscal liability for central government)?
  • What tools do we have to mitigate flood risks, and are we using them sufficiently well?
  • What constitutes best practice for flood risk mitigation in the future in different types of rivers and streams and in different parts of a catchment?
  • What complementary practices are needed for other infrastructure, eg, bridges and culverts?
  • How can river control be better integrated with the management of urban stream and stormwater systems?
  • How can the flood control activities of the relevant authorities involved (regional and local government, Transit New Zealand, Department of Conservation, Ontrack) be better integrated?
  • How do on-going urban and rural developments interact with flood protection; and is the increasing value of assets at risk considered in flood protection decisions?
  • How can councils best be enabled and supported in factoring climate change into their flood risk mitigation works?

Funding and affordability


Comprehensive flood risk mitigation may not be affordable to many communities.

Key questions this work stream addressed:

  • Who benefits from flood mitigation works, and who should pay the cost?
  • Is there a role for Government in funding flood mitigation programmes in poorer communities?

The legislation on managing flood risk and river control


  • The legislation that mandates flood risk mitigation works (the Soil Conservation and Rivers Control Act 1941) is outdated.
  • There are inconsistencies between different Acts (eg, the Building Act and the Resource Management Act).
  • There are inconsistent approaches to floodplain management and control of activities on floodplains, with associated tensions between development on the one hand and regulatory control on the other.
  • The pre-eminence given individual rights under various Acts makes it difficult to carry out comprehensive flood protection works

Key questions this work stream addressed:

  • How can the legislation be improved and updated to meet modern expectations?
  • To what extent are different Acts leading to different risk mitigation outcomes?
  • How can those inconsistencies be addressed?
  • How effective is the legislation in allowing controls on development in hazard prone areas?
  • What can be done to improve the legislation and/or current practice?
  • How difficult is it to undertake comprehensive new programmes in the current legislative environment?
  • Do we have mechanisms to allow for provision of "community goods" over private rights?
  • To what extent is the current legislative environment an impediment to comprehensive flood risk mitigation?

How to get good information on flood risk and how this information is communicated


It is difficult to convey information about hazard risks to individuals and communities.

Key questions this work stream addressed:

  • How can information about the risks from natural hazards be better communicated?
  • Is there a role for Government in doing so?

The role of central government, local government and communities


The role of central government in flood risk mitigation is unclear and disjointed, and could be improved.

Key questions this work stream addressed:

  • What is an appropriate balance between central government, local government, and the private sector (including individuals) to reduce or avoid risk?
  • What is an appropriate future role for central government, local government and the private sector (including individuals) in flood risk mitigation?
  • What are the risks to central government if it does or does not take a greater role in flood risk mitigation?
  • What are the risks to local government and communities of central government taking or not taking a greater role in flood risk mitigation?
  • Should government be prescribing and regulating for particular levels of flood risk mitigation?

See Meeting the challenges of future flooding in New Zealand for results of the review.