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Building consent for large dams

"Dam" 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.  "Dam" includes a flood control dam; a natural feature that has been significantly modified to function as a dam; a canal.  A "dam" does not include a stopbank designed to control floodwaters.

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

Do I need a resource consent or building consent to build a dam?

Resource consents

Resource consents are often required for dams as they involve the taking, using, damming and diverting of water and controlling of the quantity, level and flow of water. Also, the works associated with the dam construction itself can often trigger the requirement for resource consent.

Building consents

A building consent is required for all structures that meet the definition of a ‘large dam’ (see above definition), as well as those structures that form part of the large dam structure itself — such as appurtenant structures.

The construction of any dam, that is not a large dam is ’exempt” building work, and does not require a building consent, nevertheless section 17 of the Building Act requires all building work on dams to comply with the Building Code irrespective of the size of the dam.

This applies to the construction of new dams, the modifications of existing dams and also applies to appurtenant structures of dams.

Once details of your project are known you should discuss your development with council to identify if any resource or building consent will be required.