Dams – building consents and safety regulations

Below you will find information for building, modifying and removing a dam, as well as the new requirements for dam owners under the Building (Dam Safety) Regulations 2022.

Do I need a building consent for my dam?

Under the Building Act 2004 all “large” dams require a building consent from a regional council.

Under the Building Act, a large dam is defined as follows:

"a dam that has a height of 4 or more metres and holds 20,000 or more cubic metres volume of water or other fluid."

The height of a dam is the vertical distance from the crest of the dam, and must be measured-

"(a) in the case of a dam across a stream - to the natural bed of the stream at the lowest downstream outside limit of the dam; and

(b) in the case of a dam that is not across a stream - to the lowest elevation at the outside limit of the dam; and

(c) in the case of a canal - to the invert of the canal".

The crest of a dam is defined to mean the uppermost surface of the dam, not taking into account any camber allowed for settlement, or any curbs, parapets, guard rails, or other structures that are not part of the water-retaining structure; and for the avoidance of doubt, any freeboard is to be considered as part of the water-retaining structure.

Applying for a dam building consent

All North Island regional councils, except Auckland Council, have transferred its powers to process all building consent applications for dams to the Waikato Regional Council. The Waikato Regional Council will also undertake the inspections required during the construction phase and issue the final code of compliance certificate once the dam has been completed.

Information about the requirements for building and maintaining dams and the relevant application forms are available to download directly from the Waikato Regional Council website.

Dams Register

Northland Regional Council and other regional councils are required under the Building Act to maintain a register of large dams for their respective regions.

The register enables councils to contact large dam owners on matters of importance to them, such as new regulations and guidance material on dam safety. If you own a dam, then you should check with us whether your dam should be on the register.

To register your dam, or for general enquiries regarding dams, please contact the council's Consents team.

Dam safety regulations

The government has introduced new dam safety regulations to protect people, property, and the environment from the potential impacts of a dam failure.

The regulations have commenced as of 13 May 2024.

Purpose of the regulations

The aim of the regulations is to ensure that dams over a certain height or storage capacity are:

  • well operated and maintained
  • regularly monitored.

The regulations provide a consistent, nationwide framework by setting out minimum safety standards for dams in New Zealand.

Owners of classifiable dams (those impacted by the regulations), who have limited or no dam safety procedures in place, will need to become familiar with their responsibilities under the Building Act 2004 and the regulations, and with the actions they must take, and by when. Owners of dams classified as low potential impact will have few responsibilities. Most small dams will not be impacted by the regulations.

Read more about the regulations - legislation.govt.nz

Dams affected by the regulations

The regulation applies to ‘classifiable’ dams, which are dams that:

  • have a height of four or more metres and store 20,000 or more cubic metres of water or other fluid

How to comply with the regulations

All owners of a classifiable dam must undertake the following:

  • Determine the Potential Impact Classification (PIC) for your dam
  • Get your PIC approved by a recognised engineer
  • Submit a Dam Classification Certificate (DCC) to council
  • Review the dams PIC every 5 years.

Owners of a dam with a PIC of medium or high must undertake these additional requirements:

  • Submit a dam safety assurance programme (DSAP) to council.
  • Undertake a dam safety review.
  • Submit an annual compliance certificate.
  • Review the DSAP every 5-10 years.

Read step by step information on how to comply with these regulations - building.govt.nz

Implementation and timeframes

The timeframes vary depending on a dam's potential impact classification (PIC). Dams must be classified as either low, medium, or high potential impact, depending on the impact of the dam’s failure.

Find out what timeframes apply to your dam – building.govt.nz

Recognised Engineers

Recognised engineers also have responsibilities under the regulations. Engineering New Zealand Te Ao Rangahau, as the Registration Authority for Chartered Professional Engineers, is responsible for assessing and registering recognised engineers. Together with the New Zealand Society on Large Dams (NZSOLD), they have developed the framework and registration process for recognised engineer qualifications and competencies to be assessed.

Find a recognised engineer – engineeringnz.org

Resources to support dam owners

The following templates should be used to submit the required information to council:

Form 1: Dam Classification Certificate

Form 2: Dam Safety Assurance Programme

Form 3: Annual Dam Compliance Certificate

Building performance has developed resources to help dam owners become familiar with what is required and to prepare for the commencement of the regulations in 2024.

The resources include online learning modules, guidance documents and checklists with information to supply the regional council.

Access managing dams resources - building.govt.nz

Frequently asked questions - Dam safety regulations

A recognised engineer has completed our dam classification certificate and our dam has been classified as medium potential impact – can I use the same engineer to complete the dam safety assurance programme (DSAP)?

Depending on the recognised engineer’s competencies as assessed and registered by Engineering New Zealand Te Ao Rangahau. If they have completed the DSAP competency they will be able to sign off your DSAP.

More information can be found here: www.engineeringnz.org/public-tools/find-engineer

I have a local engineer helping me with my dam regulations whom is not a recognised engineer. They have filled out all of the paperwork. We have contacted and engaged a recognised engineer, however, they don’t agree with our local engineer and won’t certify the potential impact classification (PIC) in the dam classification certificate (DCC). What do we do?

You’ll need to work with the recognised engineer to review and agree on the PIC so the dam classification certificate (DCC) can be certified and signed off by the recognised engineer and submitted to the regional authority.

If you have questions about the engineering work of a Chartered Professional Engineer, you can raise them with Engineering New Zealand Te Ao Rangahau - submit your question here at engineeringing.org

We have engaged a technical practitioner that has some experience with dams but is not a recognised engineer, they want some more information about assessing the potential downstream effects – where else can they get help with this?

You or the practitioner could contact a recognised engineer and engage their services. You can find a recognised engineer on the Engineering New Zealand Te Ao Rangahau website: www.engineeringnz.org/engineer-tools/recognised-engineer-dam-safety

Refer to MBIE’s Dam Safety Guidance at: building.govt.nz

The latest NZ Society of Large Dams (NZSOLD) Dam Safety Guidelines has detailed information about how to carry out a PIC: nzsold.org.nz/dam-safety-guidelines-2023

I’m helping to manage the dam safety requirements for a large energy company. We already have dam safety management systems in place – can we continue operating these systems under the new regulations?

Dam owners will be able to continue operating these systems under the new regulations if they can clearly demonstrate to a recognised engineer how the dam safety management system addresses the regulations’ dam safety assurance programme (DSAP) requirements.

Refer to MBIE’s Dam Safety Guidance at: building.govt.nz - Refer to the heading “Owners of classifiable dams”.

Do regional authorities keep a register of dams in their district?

The Building Act requires regional authorities to establish and maintain a register of dams in its region as part of its administration and monitoring of dam safety regulations. All classifiable dams (from low to high potential impact classification) will be added to this register and potentially other known dams.

The register enables the regional council to contact dam owners if they need to discuss the regulations for managing dam safety.

What is the regional council’s role in relation to dams?

Where a regional authority is also a building consent authority, they can provide building consent processing and inspection services for classifiable dams, such as compliance monitoring and enforcement of the Building Code and regulations.

However, the Building Act 2004 requires all regional authorities, whether a building consent authority or not, to administer and monitor dam safety regulations.

This involves:

    • establishing and maintaining a register of dams in its district
    • considering and approving or refusing dam classifications (based on whether they have been certified by a recognised engineer as defined in the regulations)
    • approving or refusing dam safety assurance programmes
    • receiving the annual dam compliance certificates
    • adopt and implement a policy on dangerous dams, flood-prone dams, and earthquake-prone dams
    • take action, if necessary, if any dam, large or small, poses an immediate danger to the safety of persons, property, or the environment.

Transfer of functions, duties, and powers of a regional authority

A regional authority may transfer one or more of its functions, duties, or powers under the Building Act to another regional authority. Some regional authorities have transferred the consenting and inspection services for classifiable dams to a regional authority that is a building consent authority.

Regional authorities don’t plan on transferring their responsibilities when it comes to processing the dam safety regulations.
For further information read: MBIE’s dam roles and responsibilities.

What is MBIE’s role in the dam safety regulations?

They provide overall leadership of the building sector and are the central regulator for the oversight and stewardship of the regulations

Where can I find more information about the dam safety regulations?

I have a large dam on my property, will these new dam safety regulatory requirements affect me?

First check if the dam meets the Building Act’s definition of a dam and then check to see whether it is a classifiable dam.

Only dams that meet the classifiable dam thresholds are subject to the regulations.

A classifiable dam is defined in the regulations as a:

Large dam (e.g. height of four or more metres and 20,000 or more cubic metres volume of water or other fluid)

Refer to regulation 5 of the Building (dam Safety) Regulations 2022 for the meaning of a classifiable dam.

Please note: In a 28 March 2024 press release the Government agreed to raise the height threshold of the dam safety regulations from one metre to four metres. MBIE have advised the regulations need to be drafted and worked through the legislative process before the change is made officially and showing online.

How should I measure my dam?

Sometimes measuring a dam is straight forward and drawings from the dam’s construction or a record of a building consent or resource consent can be used. However, sometimes measurements of the dam will need to be taken. How easy it is to capture these measurements will depend on the type, shape, and accessibility of the dam. It is important that the height of a dam is measured accurately, and consistently. The measurements and calculations can be carried out by anyone, but the potential impact classification (PIC) must be audited and certified by a recognised engineer.

Resources for measuring dams:

When did the new regulations commence?

They began on 13 May 2024. Dam owners have up to three months after regulations commence to submit a dam classification certificate (DCC) (PDF 160 KB), which includes the dams potential impact classification (PIC) to the regional authority.

What are the offences and penalties if I don’t submit a dam classification certificate (DCC) for my classifiable dam to the regional authority?

Refer to Section 134C of the Building Act 2004 – Offence of failing to classify dam:

A person to whom section 134 applies who fails to classify the dam in accordance with section 134B commits an offence and is liable on conviction,

    1. in the case of an individual, to a fine not exceeding $50,000:
    2. in the case of a body corporate, to a fine not exceeding $150,000.

For further information refer to MBIE’s Guide to complying with the Dam Safety Regulations

I want to demolish a dam on my property rather comply with the safety regulations. What do I need to do?

If you have any plans to demolish or dewater a dam, please contact the regional authority in the first instance.

Building work includes decommissioning and demolition of dams and this may require a building consent prior to any works being undertaken.

In terms of draining or dewatering a dam, please be aware there may also be consenting requirements under the Resource Management Act.

My dam hasn’t been a problem for years, why do I now need to follow safety regulations?

While Aotearoa New Zealand had industry recommended dam safety guidance provided by the New Zealand Dam Safety Guidelines, it did not have a consistent regulatory dam safety framework until the Building (Dam Safety) Regulations 2022. This contrasted with almost all other countries who are members of the Organisation for Economic Co-operation and Development (OECD). The absence of an operative post-construction dam safety regulatory framework meant that the risks posed by dams were poorly managed. This exposed people, property, and the environment to unnecessary risk.

The Building Dam Safety Regulations 2022 ensure that classifiable dams are well operated, maintained and regularly monitored, and that potential risks of dam incidents and failures are reduced

For further information refer to MBIE’s Guide to complying with the Dam Safety Regulations

What are potential impact classification (PIC) assessments and how do they relate to classifiable dams?

The purpose of potential impact classification (PIC) assessments under the regulations are to identify and prioritise higher risk classifiable dams for further dam safety work.

All dams that are classifiable dams must have an initial PIC assessment and this must be reviewed every five years.

If your dam PIC is assessed as being Low, no further action is required until the five years review of the PIC is due.

Dams that are Medium or High PIC dams, will need to comply with additional Dam Safety Assurance Programme (DSAP) requirements, including an Annual Dam Compliance Certificate (ADCC) (PDF 52 KB).

Your PIC assessments are included in dam classification certificate (DCC) (PDF 160 KB), that must be submitted to your regional council.

How much are these dam safety requirements going to cost me?

The level of cost to the dam owner will depend on the potential impact classification (PIC) of the dam in the dam classification certificate (DCC). Different levels of PIC (low, medium or high) will require different levels of service from the recognised engineer engaged to certify the DCC and the dam safety assurance programme (DSAP).

Please contact a recognised engineer for a quote.

The benefits of protecting people, property, and the environment from the potential impacts of a dam breach far outweigh the costs of compliance. Visit building.govt.nz for further information on roles and responsibilities for dam owners.

This helpful graphic from building.govt.nz explains the implementation steps and timeframes.

Please note: There will be admin fees from regional authorities. Please refer to your relevant regional authority as costs vary between councils.

Where can I find the form for the dam classification certificate (DCC) for my dam?

Forms required by regulations and provided by MBIE provide the minimum information required to comply. However, regional authorities request the completion of some additional fields beyond the mandatory requirements of Form 1 of Schedule 3 of the Building (Dam Safety) Regulations 2022.

This data will be used to update Council's Dam Register and enable a better understanding of your region's dam portfolio.

Download the regional/unitary authority dam classification certificate (DCC) (PDF 160 KB)

MBIE's forms and other resources:

MBIE's dam classification certificate form

Alternatively, dam form templates can be found on the Complying with the regulations and the Resources pages along with other documentation and resources on the building.govt.nz website.

Can I lodge a dam classification certificate (DCC) before 13 May 2024?

The DCC can be submitted before 13 May 2024 but the regulations won’t be in force so there’s no mechanism to accept or refuse it.

However, the regional authority may be able to receive a DCC from a dam owner before 13 May, and hold it until processing on or after 13 May 2024.

What is the very last day that I need to submit the dam classification certificate (DCC) for an existing dam?

Last day to classify and register your dam is 13 August 2024 or if the dam is being built during that time or later, within 3 months of the dam being commissioned.

A new 6 metre high dam with capacity to hold about 50,000 cubic metres volume of water has recently been completed. When does the dam owner need to submit the dam classification certificate (DCC) certificate to the regional authority?

Dam owners must submit the dam’s DCC no later than three months after the regulations come into force, or no later than three months after the dam is commissioned, whichever is later.

Where can I find a recognised engineer to sign off my dam's classification certificate (DCC) certificate?

Find a qualified engineer and tips on engaging an engineer on the Engineering New Zealand Te Ao Rangahau website.

Raise your queries or concerns about engineering availability with Engineering New Zealand Te Ao Rangahau.

My dam classification certificate (DCC) has been certified and signed off by a recognised engineer, can the regional council refuse to approve this?

Refer to MBIE's Dam Safety Guidance: “The regional authority must give written notice to the dam owner as to whether they approve or refuse to approve the DCC. The regional authority can only refuse to approve the dam’s classification if they are satisfied, on reasonable grounds, that the engineer who provided the certificate is not a recognised engineer.”

This is outlined in s135 of the Building Act 2004.

Please note: that regional authorities may request the dam owner to resubmit their original DCC, where not signed by a recognised engineer.

Where do I download the dam safety assurance programme (DSAP) form?

As per the dam classification certificate form (PDF 160 KB), regional authorities request the completion of some additional fields beyond the mandatory requirements of Form 2. This data will be used to update the council's dam register and enable a better understanding of your region's dam portfolio.

MBIE's form and other resources:

MBIE's dam safety assurance programme (DSAP) Form 2

Alternatively, dam form templates can be found on the Complying with the regulations and the Resources pages along with other documentation and resources on the building.govt.nz website.

Still need help?

If you require further assistance, please reach out to dam safety team here at Northland Regional Council – [email protected]

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