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Updated 15 April 2020 12:52pm

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If you are constructing a new dam, or altering an existing dam, you are likely to require a building consent if your dam is a large dam. You may also require resource consent under the Resource Management Act 1991.

The Building Amendment Act 2013 came into force on 27 November 2013. The Act amends the definition of large dams and introduces the new categories of classificable and referrable dams.

Large dams                                                  back to top

The Building Act 2004 (the Act) gave responsibilities relating to dams to Regional Authorities – Regional Councils and Unitary Authorities. Provisions in the Act that relate to dams include:

  • Building control functions – building consents, code compliance certificates, Project Information memoranda
  • Dam safety scheme – potential impact categories, dam safety assurance programmes, annual compliance certificates, dangerous dams

Building control functions and the dam safety scheme only apply to large dams. A large dam is one that has a height of 4 or more metres, and holds 20,000 cubic metres or more of water or other fluid. The construction of dams that are not large do not require a building consent but are still required to comply with the building code.

Greater Wellington has transferred most of its building control functions to Waikato Regional Council. Waikato Regional Council has specialist expertise on the building consent process and is accredited as a Building Consent Authority (BCA).


Building consents and PIM's                        back to top

Waikato Regional Council process building consent applications for large dams in our region. Further information on the building consent process, application forms and checklists can be found on the Waikato Regional Council website. We recommend you liaise directly with Waikato Regional Council about your building consent requirements as Waikato Regional Council has the necessary expertise.  

A project information memorandum (PIM) is required by Waikato Regional Council to accompany a building consent application.  A PIM details the information a council knows about site where the proposed dam is to be constructed or an existing dam is altered.  You will need to apply for a PIM from both GWRC and the city or district council, responsible for the area where the work is proposed.


Certificate of acceptance                              back to top

A certificate of acceptance is used in situations where work has been undertaken without a building consent.  It can provide some verification for a dam owner that part or all of certain building work complies with the building code.

An application can arise as a result of:

  • a dam owner wishing to ‘legalise’ non-compliant building work ( often arises when an owner is wishing to sell a property); or
  • where GW has become aware of non-compliant work and has issued a notice to fix.

The assessment of whether a certificate of acceptance is to be granted or not, is based on the building code that was in place at the time the application is made, rather than when the work was carried out.


Dam Safety Scheme                                      back to top

The Building (Dam Safety) Regulations 2008 that were due to come in to force on 1 July 2015 have been revoked under the Building (Dam Safety) Revocation Order 2015, with effect from 30 June 2015.

Information provided by the Ministry of Business, Innovation and Employment states:

“ The Government has decided that dam safety is better suited to being managed under the Resource Management Act (RMA) rather than the Building Act. The purpose of the ongoing maintenance of dams is to manage the impacts to life, infrastructure, and ecosystems should a dam failure occur. Ministers consider that this is more consistent with the purpose and principles of the RMA.  Such an approach would also remove the current duplication between the use of resource consent to impose dam safety-related conditions, and the dam safety regulations. The latter (and the regulatory framework outlined in the Building Act) were seen by Ministers to be too onerous for the level of risk, and would impose excessive compliance costs on some dam owners.

As such, the Building (Dam Safety) Regulations 2008 have been revoked under the Building (Dam Safety) Revocation Order 2015, with effect from 30 June 2015. A Gazette notice announcing the commencement of the Building (Dam Safety) Revocation Order 2015 has now been published. “


Dangerous Dams Policy                                back to top 

The Building Act 2004 requires GWRC to review its policy on Dangerous Dams within five years of the policy being adopted.  On 29 June 2011, Greater Wellington adopted its revised Dangerous Dams Policy 2011.

The policy only applies to medium or high potential impact dams that are classifiable or referrable dams. The policy sets out how GWRC will identify dams of concern and the measures GWRC (in conjunction with the dam owner) will take to reduce or remove the danger. 

Due to amendments to the Act in 2008 the Dangerous Dams Policy also covers earthquake-prone and flood-prone dams.