The Maitai Valley Water Supply Scheme, opened in 1987, initially supplied 65 per cent of Nelson City’s water. A major emphasis in its design and construction was on quality environmental and safety standards.

Maitai Valley Water Supply 1

Maitai Valley Dam, circa 1988. IPENZ

The dam and water supply provide Nelson with an assured high quality water supply to meet its needs into the 21st century. Because of its proximity to the city its design was conservative. It also provides a degree of flood mitigation and a recreational resource.

The project is of national interest because of its high safety standards and technical design for urban water supply. The dam break analysis, by Dr Alec Sutherland of Canterbury University School of Engineering, represented state-of-the-art knowledge in this specialist field at the time.

Maitai Valley Water Supply 2

Maitai Valley Dam, circa 1988. IPENZ.

The scheme’s environmental evaluation and debate, and the resulting provisions for environmental enhancement and safeguards are unsurpassed in New Zealand for this type of project. It highlights the level of planning and public involvement needed to adequately develop an environmentally sensitive project, and the need to budget for associated time and costs.

The intake facilities of the dam are of special design and form a key part of technical measures making water treatment unnecessary.

Heritage recognition

IPENZ “Engineering to 1990” project

This item of New Zealand’s engineering heritage was recognised as part of the IPENZ “Engineering to 1990” project which the Institution organised to help celebrate the country’s sesquicentenary in 1990. A plaque was unveiled to mark the significance of this water supply as part of the development of the nation.

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The Maitai Dam is part of the Nelson City Council's Dun Mountain Trail.