19 August 2015

Benmore Power Station

  • Benmore penstock, July 2004. Photograph courtesy of R. Aspden.
  • Benmore Dam, 2004. Photograph courtesy of R. Aspden.
  • Benmore dam [15 March 1969]. Ref: WA-68479-F. Alexander Turnbull Library, Wellington, New Zealand.

The Benmore Power Station at Otematata, South Island, is the power source for the high voltage direct current link to the North Island. Construction on the Benmore project began in 1958 and the power station was opened in 1965 to coincide with the completion of the Benmore to Haywards H.V.D.C. link.

Benmore Dam is the largest earth dam in New Zealand and, at 118 metres to crest, is also the highest. Impounded behind it is New Zealand’s largest man-made lake which provides various recreation facilities. In front of the dam the massive pre-stressed concrete penstocks are a unique feature.

Designed and constructed by New Zealand's Ministry of Works and the Electricity Department, the power station contributes about 2200 Gigawatt Hours per year to New Zealand's national grid.

The development and construction of the Benmore Power Station, and the link to Haywards in the North Island, was of national interest and featured in several documentaries including, Selwyn Toogood's 1964 film These New Zealanders (below) and later Inter-Island Power (1966).

Meridian Energy Limited owns the Benmore Power Station and other facilities around New Zealand.

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 power station as part of the development of the nation. A photo of the plaque is attached.

More information


Waitaki River near Otematata, North Otago.


Proceed up the Waitaki valley from Oamaru on State Highway 83, then right opposite Otematata.  There is well signposted lookout that provides good view of the facilities.

Further reading

B. J. Butcher, 'Concrete for Benmore Power Project,' (PDF 345KB) New Zealand Engineering, Vol.20:1, 1965.

H. C. Hitchcock, 'Main generating and electrical equipment for Benmore Power Station,' (PDF 665KB) New Zealand Engineering, Vol.20:1, 1965.

O. T. Jones, 'Design of Benmore Earth Dam,' (PDF 680KB) New Zealand Engineering, Vol.20:1, 1965.

T. Story, 'Earthmoving for Benmore Earth Dam,' (PDF 615KB) New Zealand Engineering, Vol.20:1, 1965.