Dam Safety

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 has now reviewed and updated the policy on dangerous dams, earthquake-prone dams and flood-prone dams to align with the new Building (Dam Safety) Regulations 2022 which come into effect in May 2024.

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.

The policy has been notified, and no submissions were received. Council adopted this policy on 26 June 2024.

Dam Safety Regulations 2022

If a dam is four or more metres in height and stores 20,000 or more cubic metres volume of water, or other fluid, it is a classifiable dam and is impacted by the regulations.

Small dams are excluded from the regulations. This includes small 'turkey nest' dams, irrigation races, stock drinking ponds and weirs. If a dam is not classifiable, this means it is not impacted by the regulations and no further action is required by dam owners.

Dam owners with a classifiable dam must assess the potential impact their dam’s failure could have on the community, historical or cultural places, critical or major infrastructure, and the natural environment.

This assessment will determine the dam's Potential Impact Classification (PIC) which will be either low, medium, or high.

Owners of dams with a low potential impact classification will have few responsibilities. Dam owners can determine their dam's PIC themselves, but this must provided to a Recognised Engineer for audit and certification.

The regulations do not require that PIC assessments follow the procedures outlined in the New Zealand Dam Safety Guidelines. While many PIC assessments may draw from these guidelines, the regulations allow those undertaking the assessment to make simplifying assumptions and apply pragmatism where appropriate.

Once the PIC of a dam has been determined, it needs to be submitted it to a Recognised Engineer for audit and certification.

The Recognised Engineer will work with the dam owner to complete a dam classification certificate. The certificate contains:

• information about the dam
• the PIC given to the dam
• information about the dam owner
• certificate of the Recognised Engineer.

A Dam Safety Assurance Programme (DSAP) is required for dams with a medium or high PIC. Dams with a low PIC do not require a DSAP.

Implementation

For classifiable dams, Section 135(2) of the Building Act requires the dam owner to submit a potential impact classification (PIC) to the regional authority up to three months after regulations commence (13 May 2024) or the dam is commissioned (whatever is later). This is the first requirement.

A full list of requirements can be found in these documents from the Building Performance website:

Dam safety - implementation steps and timeframes (building.govt.nz)

Guide to complying with the Dam Safety Regulations

The Dam Safety Scheme forms available in the sidebar are the forms that dam owners are required to submit to the Regional Council (forms 1-3).

Contact us

For any questions, contact us at damsafety@hbrc.govt.nz