What is a Dam?
A 'Dam’, as defined by section 7 of the Building Act 2004:
(a) means an artificial barrier, and its appurtenant structures, that –
- is constructed to hold back water or other fluid under constant pressure so as to form a reservoir; and
- is used for the storage, control, or diversion of water or other fluid; and
(b) includes –
- a flood control dam; and
- a natural feature that has been significantly modified to function as a dam; and
- a canal; but
(c) does not include a stopbank designed to control floodwaters.
‘Appurtenant structure’ is defined in section 7 of the Building Act 2004 as a structure that is integral to the safe functioning of the dam as a structure for retaining water or other fluid.
Overview of Dam Safety Regulations 2022
The new regulations on Dam Safety [Building (Dam Safety) Regulations 2022] were announced by the Ministry of Business, Innovation and Employment (MBIE) in May 2022 which set out the minimum requirements for dam safety in New Zealand.
Until now, New Zealand was one of the few OECD countries that had lacked a consistent, national-level scheme to ensure ongoing maintenance and inspection of dams. The recently announced dam safety regulation now changes that. The new approach will 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.
The new dam safety regulations will commence on 13 May 2024. This gives the dam owners time to check whether their dam is big enough to be impacted and take steps to ensure that their dams and associated paperwork are consistent with the regulation. These regulations will apply to all the ‘Dams’ that fall under the definition of a ‘Classifiable Dam’ as specified in Building (Dam Safety) Regulations 2022 that are:
- 4 metres or higher and store 20,000 or more cubic metres volume of water or other fluid; or
- 1 metre or higher and store 40,000 or more cubic metres volume of water or other fluid.
From 13 May 2024, the owners of Classifiable Dams will need to confirm the potential risk their dam poses, put in place dam safety plans and undertake regular dam inspections.
The new dam safety regulations require that all classifiable dam owners engage a ‘Recognised Engineer’ to certify the Potential Impact Classifications (PIC) of the dam and submit it to Council for approval within three months of the regulations commencing, or no later than three months after the dam is commissioned, whichever is later.
Dams with approved Medium and High Potential Impact Classification will be required to have a ‘Dam Safety Assurance Programme’. These dams will be required to have regular monitoring and surveillance practices in place for the safe operation of dams and will need to submit an ‘Annual Dam Compliance Certificate’ to Reginal Authority which is certified by a Recognised Engineer. Low potential impact dams will have no ongoing requirements except for their initial potential impact classifications and then regularly review their potential impact classification at a 5-year interval.
The key groups impacted by the new dam safety regulations are dam owners, recognised engineers, and regional authorities. This is because the regulations require these groups to carry out certain actions to meet their legal obligation.
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.
The Marlborough District Council and other Regional Councils throughout New Zealand are required under the Building Act 2004 to maintain a register of all dams for their respective regions.
The register enables Councils to contact dam owners on matters of importance to them, such as new regulations, guidance material on dam safety, and emergency response. If you own a dam, then you should check with the Council whether your dam should be on the register.
- Infographic Summary of Implementation Steps and Timeframes
- Building (Dam Safety) Regulations 2022
- MBIE’s Building Performance Website
- The Dam Safety Guidance Document
- How to Measure and Calculate Agricultural Dam’s Height and Volume
- MBIE’s On-line Learning Module
- New Zealand Dam Safety Guidelines, 2015 – NZSOLD