A dam is an artificial barrier and any structures that are essential to the safe functioning of the dam – (including the pump house, power source, conduits, penstocks, spillways, sluice gates, intake tower, etc) that is

  • constructed to hold back water (or other fluid) in a reservoir
  • used for the storage, control, or diversion of water (or other fluid).

The definition of a dams under the Building Act 2004 includes a

  • flood control dam
  • natural feature significantly modified to function as a dam
  • canal.

A dam does not include a stop bank designed to control floodwaters.

All large dams require a building consent from the Regional Council (Environment Canterbury) if they are

  • more than 4 metres in height, and
  • hold more than 20,000m3 of water (or other fluid).

You will need to get in touch with Environment Canterbury (ECan) to discuss building consent requirements for dams.

Smaller dams can be built without a building consent under Exemption 22 of Schedule 1 of the Building Act 2004 (refer building work that does not require a building consent).