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Dam Safety

Use this page to find out about dam safety regulations and our review of the current Dangerous Dams Policy.

Dangerous dams policy review

The Building Act 2004 introduced legislation for managing the safety of existing and new dams in New Zealand. Under this Act, regional councils must have a policy on how they will deal with dangerous dams, earthquake-prone dams and flood-prone dams in their region, and how the policy will apply to heritage dams.

Hawke’s Bay Regional Council is in the process of reviewing and updating the policy on dangerous dams, earthquake-prone dams and flood-prone dams.

This policy sets out what Hawke’s Bay Regional Council will do in relation to a dangerous, earthquake-prone or flood-prone dam in the Hawke’s Bay region. It is a short policy that covers our regulatory and legislative responsibilities in relation to these dams under the Building Act 2004.

If you have any feedback or comments on the draft policy, please make a submission during the consultation period from 28 March to 28 April 2024. You can make a submission by completing the submission form linked below.

Dam Safety Regulations submission form

You can decide at the time you lodge a submission whether you wish to speak to your submission at a hearing.

Once the submissions have been collated, hearing dates and venues will be chosen if applicable. If hearings are applicable, once they take place, the hearing panel will deliberate and finalise the policy which will commence on 13 May 2024, the same day the Dam Safety Regulations take effect.

More Information

For more information, please refer to the statement of proposal, summary of information and proposed policy on dangerous dams, earthquake-prone dams and flood-prone dams. These consultation documents are all available on this page.

For any questions, contact us at

What happens next?

The Council will collect and analyse all submissions, and these will be presented to a hearings committee should this be required. After the hearing, the Council will consider all the submissions received and make decisions on any amendments to the proposed policy as a result. All submitters will be notified of the Council’s decision.

This policy will generally only impact you if you have a classifiable dam that either you or your recognised engineer believes to be dangerous, earthquake-prone or flood-prone.

  • A dam is classifiable if it has a height of 4 or more meters and stores 20,000 or more cubic meters volume of water or other fluid as defined in regulation 5 of the Building (Dam Safety) Regulations 2022.

  • Many small farm dams and ponds will be excluded from the regulations as they are unlikely to exceed the height and volume thresholds above.

Dangerous dams

Section 153 of the Building Act 2004 provides that a dam is ‘dangerous’ if it:

(a) is a dam classified as having a potential impact classification of medium or high; and

(b) is likely to fail -

  1. in the ordinary course of events; or
  2. in a moderate earthquake (as defined in the regulations); or
  3. in a moderate flood (as defined in the regulations).
Earthquake-prone dams

Section 153A of the Building Act 2004 includes the definitions for a ‘earthquake-prone’ or ‘flood-prone’ dam.

A dam is an earthquake-prone dam if the dam:

(a) is a high potential impact dam or a medium potential impact dam; and

(b) is likely to fail in an earthquake threshold event (as defined in the regulations).

The definitions of a ‘moderate earthquake’, a ‘earthquake threshold event’, a ‘moderate flood’ and a ‘flood threshold event’ are provided in regulation 19 of the Building (Dam Safety) Regulations 2022.

Flood-prone dams

A dam is a flood-prone dam if the dam:

(a) is a high potential impact dam or a medium potential impact dam; and

(b) is likely to fail in a flood threshold event (as defined in the regulations).


Section 153 and 153A of the Building Act 2004 can be accessed on the New Zealand Legislation website.

The policy must be read alongside the regulations which defines terms used in the Building Act in relation to dangerous, earthquake-prone and flood-prone dams.

The policy does not impact on your obligations under the regulations as a dam owner.

The policy sets out The Regional Council's approach and priorities it will take in performing its functions in relation to dangerous, earthquake-prone and flood-prone dams in the Hawke’s Bay region.

For more information on the Dam Safety Regulations please find helpful resources here:

Dam safety resources

The regulations come into force on 13 May 2024.

Council has always had a policy on dangerous, earthquake prone and flood prone dams. Dam owners will continue to have the primary responsibility for identifying, monitoring, reviewing and reporting on dangerous, earthquake-prone and flood-prone dams and for reducing or removing the risk of harm to people, property and the environment.

The Building Act requires dam owners (with medium or high potential impact classification) to immediately notify HBRC if they have reasonable grounds to believe their dam is dangerous.

The Act (and Policy) places obligations on a recognised engineer (engaged by the owner to provide a certificate for the purposes of sections 135(1)(b), 142(1)(b) or 150(2)(f) of the Act) to notify HBRC and the dam owner if he or she believes that the dam is dangerous.  This must be done within 5 working days after the engineer forms their belief.

Unless the circumstances dictate otherwise, HBRC will seek to discuss options for action with the dam owner, with a view to obtaining from the owner a mutually acceptable proposal for reducing or removing the danger:

  • HBRC may give written notice requiring the owner to carry out work on the dam, within a specified timeframe, to reduce or remove the danger.

  • HBRC may direct and take action itself in certain circumstances, such as where there is immediate danger to the safety of persons, property, or the environment.

  • For dams that are heritage dams, advice may be sought from Heritage New Zealand/Pouhere Taonga regarding any heritage values of the dam.

  • HBRC will notify potentially affected communities downstream of a dangerous, earthquake-prone or flood-prone dams.  The Ministry of Business, Innovation, and Employment, relevant territorial authorities, relevant iwi authorities, Hawke’s Bay Civil Defence and Emergency Management Group and Heritage New Zealand/ Pouhere Taonga may also be notified.


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While every endeavour has been taken by the Hawke's Bay Regional Council to ensure that the information on this website is accurate and up to date, Hawke's Bay Regional Council shall not be liable for any loss suffered through the use, directly or indirectly, of information on this website. Information contained has been assembled in good faith. Some of the information available in this site is from the New Zealand Public domain and supplied by relevant government agencies. Hawke's Bay Regional Council cannot accept any liability for its accuracy or content. Portions of the information and material on this site, including data, pages, documents, online graphics and images are protected by copyright, unless specifically notified to the contrary. Externally sourced information or material is copyright to the respective provider.

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