The regulations on Dam Safety [Building (Dam Safety) Regulations 2022] from the Ministry of Business, Innovation and Employment (MBIE) set out the minimum requirements for dam safety in New Zealand.

The regulations provide a framework to protect people, property and the environment from the potential impacts of dam failure, both in the immediate vicinity of dams and further downstream.

ORC staff member checking height of dam

The new dam safety regulations commence on 13 May 2024 and apply to all dams that exceed the threshold imposed in the definition of ‘Classifiable Dam’, as specified in Building (Dam Safety) Regulations 2022, as being:

  • 4 metres or higher and storing 20,000 or more cubic metres volume of water or other fluid


Dam owners will need to check if a dam/s exceeds the new threshold. It is vital that dam owners measure their dam in line with the guidance supplied by MBIE (in Section 7.2 of the MBIE “Guide to complying with the Dam Safety Regulations”) to ensure that it meets the measurement of dam requirements imposed under s133B of the Building Act 2004.

The "Height and volume threshold" graph below shows the threshold imposed in the new regulations. Any dam that exceeds this threshold is regarded as a Classifiable Dam and is required to the meet the new regulations.


Height and volume threshold for a classifiable dam


Dam safety reporting requirements

If a dam exceeds the threshold and is confirmed to be a Classifiable Dam, the dam owner will need to carry out a Potential Impact Classification (PIC) assessment. This is to assess the potential impact (i.e. low, medium or high), the dam’s failure could have on the community, historical or cultural places, critical or major infrastructure, and the natural environment.

The regulations allow for anyone to carry out a PIC assessment. This includes:

  • dam owners
  • farm consultants
  • technical practitioners

However, owners of a Classifiable Dam are required to engage a ‘Recognised Engineer’.

MBIE has developed the "Checklist for dam owners" which will help the owners of typical agricultural dams identify and collate information which would assist with the completion of a PIC assessment. 


A Recognised Engineer will need to audit and certify the PIC assessment of the dam and submit a Dam Classification Certificate to ORC for approval by 13 August 2024.


A PIC assessment can be submitted by completing Form 1: Dam Classification Certificate and sending it to This needs to be submitted by 13 August 2024.

Owners of dams assessed as having a low potential impact will have fewer responsibilities, whereas those with a medium or high potential impact will be required to have a certified Dam Safety Assurance Programme and submit Annual Dam Compliance Certificates. These can be submitted by completing Form 2: Dam safety assurance program & Form 3: Annual dam compliance certificate and sending these to

Further reporting requirements, additional to the supply of a PIC assessment, which dam owners need to meet depend on whether their dam is assessed as low, medium or high impact.

This infographic from MBIE Dam Safety Regulations 2022 will help dam owners to understand their responsibilities.


Submission of Dam Safety Reporting

The editable Form 1: Dam Classification Certificate is required to be audited and certified by a Recognised Engineer and supplied by 13 August 2024 for all Classifiable Dams.

If your dam has a certain level of impact, Form 2: Dam Safety Assurance Programme & Form 3: Form 3 - Annual Dam Compliance Certificate will need to be completed. These also need to be audited and certified by a Recognised Engineer.

Supply these completed forms, along with supporting information via email to

Want to know more?

View the Building (Dam Safety) Regulations 2022.

Further information and resources to support dam owners and Recognised Engineers with their responsibilities under the new regulations are available on MBIE’s Building Performance Website This includes an online learning module and also a guidance document prepared by MBIE, which are excellent starting points to become familiar with the new dam safety regulations.

Building Performance - Resources 
Building Performance - Managing dams to ensure they are safe
Building Performance - Infographic

For additional information and insights on how to calculate the volume of your dam, please see the Ministry of Business, Innovation & Employment (MBIE) resource: Measuring and calculating the height and volume of agricultural dams

NZ Society on Large Dams (NZSOLD) is a technical group of Engineering New Zealand. This site has information on dam safety and construction, including the proceedings of conferences at which papers on dam safety and background to the Building Act dam safety legislation have been presented. Find out more information on the NZSOLD website:

Engineering New Zealand Te Ao Rangahau has information on about how to find an engineer and/or a Recognised Engineer, and tips how to effectively engage with them.

Find out historic information on some Otago dams from the Heritage New Zealand Pouhere Taonga.

For all further enquiries please email or alternatively contact our customer services team on freephone 0800 474 082.


This flowchart from MBIE's Guide to complying with the Dam Safety Regulations, will help dam owners to understand their responsibilities.

Frequently Asked Questions

Page last updated 8 July 2024.