Dam safety regulations and requirements

New dam safety regulations have been introduced by the Ministry for Business, Employment and Innovation (MBIE). They're designed to provide a nationally consistent approach to dam safety, ensuring dams and similar structures are well-operated, maintained and monitored.

The regulations are designed to reduce the impact on people, property, or the environment from incidents that could cause these structures to fail.

Under the Building Act 2004, we as a regional authority are required to maintain a register of all dams in the Canterbury region. This register enables a better understanding of Canterbury's dam portfolio and assists us in providing appropriate support and resources to dam owners, including in emergencies.

Changes to the regulations

On 28 March 2024, the Government changed the height and volume thresholds of a classifiable dam.

The regulations will no longer apply to dams that are less than four metres high, regardless of their storage volume.

A classifiable dam is now defined using a single height and volume threshold of four metres or higher and 20,000 or more cubic metres of stored liquid.

Note: Following the above announcement, the Building (Dam Safety) Regulations 2022, Section 5(1) will be revised in due course to show the amended meaning of a classifiable dam.

Your requirements

If you have a dam or similar structure on your property, you need to determine if it falls under the new regulations.

Whether it’s classifiable under the new regulations depends on its height and the volume of water/fluid it can store above natural ground level.

The new regulations apply to dams that are four or more metres in height and store 20,000 or more cubic metres of water or other fluid.

For a list of recognised engineers go to Engineering New Zealand's website.

MBIE has a resource to help you calculate the volume of your dam (PDF file 7.9MB) and understand if you are impacted by the regulations.

Submit a dam classification certificate

If it does, you will need to carry out a potential impact classification (PIC) to assess the potential impact (i.e. low, medium, or high impact) dam failure could have on the community, historical or cultural places, critical or major infrastructure, and the natural environment.

You must provide your dam classification certificate, which you will need to get certified by a recognised engineer.

You may have further obligations depending on whether your dam is assessed as low, medium, or high impact.

Owners of dams assessed as having a low potential impact will have fewer responsibilities, whereas those with a medium or high potential impact will have more responsibilities.

Fill in a dam classification certificate form

Submit a dam safety assurance programme

A Dam Safety Assurance Programme (DSAP) is only required for dams with a medium or high PIC.

The DSAP provides dam owners with a structured framework of plans and procedures to plan and complete the activities required for the safe operation and management of their dams.

For a medium PIC dam, the DSAP must be:

Certified by a recognised engineer and submitted to us for approval up to two years after the regional authority approves the PIC.
Reviewed within ten years after the date on which the regional authority approves the DSAP, and then after the first review, at intervals of not more than seven years.

For a high PIC dam, the DSAP must be:

Certified by a recognised engineer and submitted to us for approval up to one year after the regional authority approves the PIC.
Reviewed within five years after the date which the regional authority approves the DSAP, and then after the first review, at intervals of not more than five years.

Fill in a dam safety assurance programme form

Submit an annual dam compliance certificate

An annual dam compliance certificate is only required for dams with a medium or high PIC.

On each yearly anniversary of the dam's DSAP approval, you as the owner of the dam must have a recognised engineer audit evidence of their compliance with the DSAP and prepare an annual dam compliance certificate.

Either you as the owner, or the recognised engineer needs to provide a copy of the certified annual dam compliance certificate to us.

Fill in an annual dam compliance certificate form

The other key groups impacted by the regulations are technical practitioners, including recognised engineers, and regional authorities. This is because the regulations require these groups to carry out certain actions. Find out more about their roles and responsibilities.