New regulations on dams aim to protect NZ from 'potentially catastrophic impacts'

4:40 pm on 2 March 2021

New safety regulations on dams, setting limits on how high they can be and how much water they can hold, are coming in.

Aerials and stills of the Upper Mangatangi Dam at 44% of capacity

Photo: RNZ / SIMON ROGERS

The regulations set up a regime for inspecting and maintaining at least 1500 dams.

Ministry of Business, Innovation and Employment (MBIE) announced today that Cabinet had approved policy decisions for the development of the new safety regulations.

"Dams are an essential part of our infrastructure - for water supply, power generation, irrigation, mining and storm water management. Cabinet's decision today recognises the importance of ensuring this part of our infrastructure remains robust, safe and well cared for," MBIE's Building Policy Manager Amy Moorhead said.

While the Building Act regulates construction of dams, and they are required to have building consent, there is no regulatory requirements to ensure they are maintained and inspected after being built, Moorhead said.

"The policy decisions agreed to pave the way for new regulations that will provide an approach to dam safety that will protect New Zealand from the potentially catastrophic impacts dam failures can have on communities, cultural sites, critical infrastructure and the natural environment."

The new regulations will impose new height and volume thresholds, and establish a system to assess a dam's potential impact to fail, and the effect that would have on people, property and the environment.

Low risk structures such as small, low dams, and stock drinking ponds are exempt.

Moorhead said the regulations will be based on internationally reviewed guidelines written by the New Zealand Society on Large Dams.

There will be a two-year implementation period.

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