Building Consents for Large Dams
What is a large dam?
A landowner proposing to build a dam or carry out work to an existing one, must first determine whether it is a ‘large dam’. These are defined in the Building Act 2004(external link) as having a:
- height of 4m or more; and
- volume of 20,000m³ or more of water
The landowner must then make a building consent application for all structures that meet this definition. This includes flood control dams, significantly modified natural features and canals, as well as structures that form part of large dams, such as appurtenant structures.
What is a building consent?
A building consent is a formal document issued by a BCA, authorising an applicant to carry out building work in accordance with the approved plans and specifications.
A BCA must grant a building consent if it is satisfied on reasonable grounds that the provisions of the building code would be met if the building work were properly completed in accordance with the plans and specifications that accompanied the building consent application.
Dam Building Consents
From 1 June 2021 Environment Canterbury (ECan) began processing all Building Consents and Code Compliance Certificates for the Otago, Southland and West Coast Regions. ECan are responsible for issuing building consents for large dams, as well as ensuring large dams are well constructed, regularly monitored and that the potential risks to people and property are minimised.
Environment Canterbury is a Building Consent Authority (BCA) accredited with International Accreditation New Zealand and is also registered with the Ministry of Business, Innovation and Employment.
For more information on consenting large dams, go to: www.ecan.govt.nz/do-it-online/resource-con or contact:buildingconsents@ecan.govt.nz.
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While Building Consents and Certificates of Compliance (CCC) are to be received by Environment Canterbury, the West Coast Regional Council must receive Certificates of Acceptance (COA) for the West Coast Region. These will be processed or the co-ordination of the processing managed by the West Coast Regional Council. You will be notified of who is processing your COA once it has been received.
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Preparing for new dam safety responsibilities
Contribution from the Building Performance team at the Ministry of Business, Innovation and Employment
It is less than a year until the new dam safety regulations 2022 (the regulations) commence on 13 May 2024. The regulations provide a nationally consistent approach to ensuring that dams are, and remain, safe, protecting people, property and the environment.
Why the regulations have been made
The regulations, made by the Government in May last year, ensure that classifiable dams are well operated, maintained and regularly monitored. They also ensure that potential impacts of dam incidents and failures are reduced, protecting people, property and the environment.
Until recently, Aotearoa New Zealand was one of the few countries in the Organisation for Economic Co-operation and Development (OECD) which did not have a consistent regulatory dam safety framework.
You can find the regulations on the New Zealand Legislation website.
How to prepare - action for dam owners
Owners of dams need to determine if their dam is a classifiable dam. Only classifiable dams are impacted by the regulations. A dam is classifiable if it is:
- Four or more metres in height and stores 20,000 or more cubic metres volume of water, or other fluid; or
- One or more metres in height and stores 40,000 or more cubic metres volume of water, or other fluid.
If a dam meets the above requirements, the dam owner will need to become familiar with their responsibilities under the regulations. These responsibilities include assessing their dam’s potential impact on the surrounding area if it were to fail.
Other responsibilities will vary depending on the outcome of the assessment. Owners of dams assessed as having a lower potential impact on the surrounding area will have fewer responsibilities, whereas those with higher potential impacts will have more responsibilities.
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.
You can find more information about this at Recognised Engineer (dam safety) | Engineering NZ
Information and resources to support dam owners
Building Performance has developed resources to help dam owners understand and prepare for their responsibilities. This includes a resource to help dam owners calculate the volume of their dam themselves, which in turn helps them understand if their dam is impacted by the regulations.
The resources also include a detailed guidance document and three form templates, which list the information dam owners must provide to regional authorities.
You can find these resources, plus others, on the Building Performance website.
The New Zealand Society of Large Dams are also currently updating their industry Dam Safety Guidelines to reflect the new regulations.
