Dam safety and consents

Dams are regulated under both the Building Act 2004 and the RMA. The Council transferred many of its Building Act responsibilities to Waikato Regional Council, but retains responsibility for specific dam safety responsibilities and all RMA matters.

Managing dam safety

The Building (Dam Safety) Regulations 2022(external link) (the regulations) started 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.

The regulations only apply to classifiable dams. These are dams that are four or more metres in height and stores 20,000 or more cubic metres volume of water, or other fluid.

Owners of classifiable dams can read about their responsibilities under the regulations on the Building Performance website(external link). The key requirements for owners of existing dams in Taranaki are to:

  • Submit a potential impact classification (PIC) to the Council by 13 August 2024. This classification must be done by a Recognised Engineer. A dam will be classified as a low, medium or high PIC. A dam must be recertified every five years.
  • Owners of medium PIC dams then must submit a dam safety assurance programme (DSAP) to the Council within two years of the Council approving the PIC. Owners of high PIC dams have 12 months. A DSAP must also be approved by a Recognised Engineer. A DSAP for a medium PIC dam must be reviewed within 10 years, and within five years for a high PIC dam.

The relevant forms for submitting a PIC and DSAP to the Council can be found on the Waikato Regional Council website(external link).

The register of Recognised Engineers can be found on the Engineering New Zealand website(external link). 

Beyond the regime set up by the regulations, the Taranaki Regional Council also has responsibility for managing dams that have been deemed dangerous, earthquake-prone or flood-prone. How we will work to address safety risks from these dams is set out in our Policy on Dangerous Dams, Earthquake-Prone Dams and Flood-Prone Dams (see below). The Council also maintains a register of all classifiable dams in Taranaki.

TRC Dangerous Dams Policy (Approved 2 April 2024) [PDF, 415 KB]

(external link)

Building consents

All dams must comply with the NZ Building Code, and all large dams (over 4m in height and retaining more than 20,000 cubic metres of water or other fluid) require a building consent. The Council has delegated the processing of building consents for dams to the Waikato Regional Council. Information on the building consent process, and all relevant forms, can be found on the Waikato Regional Council website(external link).

Resource consents

Medium to large dams are also likely to require a resource consent under the Resource Management Act 1991 (RMA). Small farm dams, not designed for river or flood control or to drain land or wetlands, are generally allowed without a resource consent if certain conditions are met. An exception is the Stony River catchment, where any damming is prohibited. Conditions placed on any dam related resource consent are to protect the waterway ecology and the stability of the streambed.

To not require a resource consent outside of the Stony River catchment, you need to ensure:

  • The catchment area upstream of the dam is less than 25 hectares.
  • The dam is no more than three metres high.
  • You are not damming water outside of your own property or causing a build-up of water on neighbouring properties.
  • The dam can let floods pass, via a proper spillway, and does not alter the natural course of the river.
  • You are not restricting anyone else's water supply or resource consent.
  • No significant environmental effects, including scouring, erosion, or restriction of fish passage is occurring.
  • No contaminants from equipment are being allowed to enter the river (make sure you do not refuel any equipment in the riverbed).
  • The dam does not restrict fish passage.
  • Construction does not take place between 1 May and 31 October in areas covered by water, due to fish spawning during this time.
  • The Council is informed that you are going to dam the stream, at least two working days before you start work.

If you cannot meet all of these requirements, you may still be able to construct the dam but you will need a resource consent.

  • Please note a deposit of $123 (excluding GST) is required for lodging a PIC, DSAP and annual dam safety compliance certificate. Actual costs are based on the Council's standard hourly rates.

Contact us

If you require further information, please get in touch.