Building consents: dams

Dam safety scheme

Dam safety depends upon design, construction and the management of the dam structure.  Therefore, the way in which you build and manage your dam structure will affect its safety aspects.

The dam safety provisions of the Building Act come into force on 1 July 2010 (refer S135-148).

The date a dam is first put to use (commissioned) will dictate when dam owners are required to provide certified dam classifications to regional councils (i.e. ARC) in accordance with Section 135 of the Act.

Where a dam was commissioned before 1 July 2010, an owner has until 1 October 2010 to provide the classification information to the relevant regional council.

For dams commissioned after 1 July 2010, owners have three months from the date that the dam was commissioned, to provide classification information to ARC.

ARC is currently developing its dam safety regime.

Engaging an engineer to do a dam classification

The Institution of Professional Engineers New Zealand (IPENZ) is the professional body which represents professional engineers from all disciplines in New Zealand.

ARC recommends that dam owners look through the IPENZ website listing of recognized engineers to check that the engineer they have chosen to make the classification of their dam has a current CPEng.

High impact dams must be assessed by a Category A Recognized Engineer listed on IPENZ website.

Low impact dams can be classified by either a Category B or Category A Recognized Engineer.

We suggest that the dam owner asks their selected engineer to answer the minimum of these two questions in writing:

• does the engineer have ability and experience in general civil engineering?
• is the engineer a CPEng and competent to perform the work involved?

This is because a dam owner may not be highly skilled or knowledgeable in the dam safety scheme and may need some advice.