Dams, safety requirements and building consents

Farm dam in Northland.All North Island regional councils except Auckland Council has transferred its powers to process all building consent applications for dams to the Waikato Regional Council.

The Waikato Regional Council will also undertake the inspections required during the construction phase and issue the final code of compliance certificate once the dam has been completed.  

Brochures and application forms

A series of brochures about the requirements for building and maintaining dams and the relevant application forms are available to download directly from the Waikato Regional Council website.



Dam Safety Scheme and Dam Register

The Building Amendment Act 2013 (the Act) became law on 28 November 2013 and contains a number of provisions relating to dams and the dam safety scheme.

A large dam is now defined as follows:

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

where the method for measuring the height of a dam is provided in the Act (Section 133B), as is the definition of a crest for the purposes of measuring that height.

The height of a dam is the vertical distance from the crest of the dam, and must be measured-

"(a)  in the case of a dam across a stream - to the natural bed of the stream at the lowest downstream outside limit of the dam; and

(b)  in the case of a dam that is not across a stream - to the lowest elevation at the outside limit of the dam; and

(c)  in the case of a canal - to the invert of the canal".

The crest of a dam is now defined to mean the uppermost surface of the dam, not taking into account any camber allowed for settlement, or any curbs, parapets, guard rails, or other structures that are not part of the water-retaining structure; and for the avoidance of doubt, any freeboard is to be considered as part of the water-retaining structure.

Changes have also been made to the requirements and obligations relating to dams under the dam safety scheme, though these changes will only take practical effect when the Building (Dam Safety) Regulations come into force on 1 July 2015.

Dams Register

Northland Regional Council and other regional councils are required under the Building Act to maintain a register of large dams for their respective regions.

The register enables councils to contact large dam owners on matters of importance to them, such as new regulations and guidance material on dam safety. If you own a dam, then you should check with us whether your dam should be on the register.

Contact details

To register your dam, or for general enquiries regarding dams, please contact:

Northland Regional Council
Phone: 0800 002 004 
Email: info@nrc.govt.nz