We 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(external link).

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.

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.

Engaging an engineer

A landowner will usually engage with an engineer to design their dam and apply for the building consent.

Checks should be made to ensure they have the necessary experience and qualifications relating to dam engineering and safety assurance. The Engineering New Zealand(external link) or the Association for Consulting and Engineering Professionals NZ(external link) can help with this.

Resource consent

Before beginning construction work, a landowner must also consider whether a resource consent is required to dam water. A consent may be required under the Resource Management Act 1991 where taking, using, damming, and diverting water is anticipated.

Works associated with dam construction may also trigger the need for resource consent, such as carrying out earthworks.