Harihari power scheme under way

Work to rebuild a hydro power scheme on the Amethyst River, near Harihari, is on track with a 1.8km road now formed to the tunnel portal site.
Westpower says about 4000 South Westland homes will benefit from the development of the 6MW scheme, which is a joint venture between Westpower and Harihari Hydro Ltd. It is expected to be operational by 2013.
Westpower chief executive Rob Caldwell said yesterday the project was running to schedule, with tunnel contractors now having access to the operational site.
“We anticipate that portal establishment will commence late September, and following that tunnelling will commence.”
The extra generation would provide a “steep change in security of supply”, both south to the glaciers and north to Hokitika.
Unlike other hydro-electric proposals the Amethyst Hydro Ltd scheme gained all consents required without meeting any opposition. It was given the green light in January, and the first sod was turned in April.
The Amethyst River, a small tributary of the Wanganui River just east of Harihari township, was the site of a small hydro station that opened in 1954 and was shut by Westpower in the late-1980s.
Mr Caldwell said the old plant had become unviable and needed major works to the entire scheme for it to run safely.
However, tourism and farming activity in Westland, and recent legislation amendments to enable line suppliers to operate generation schemes, led the power company to reinvestigate the Amethyst scheme, together with Harihari Hydro Ltd, which had a 20% stake in the scheme.
Although parts of the old hydro scheme are still visible, none of it will be touched for the rebuild. Under the new scheme, the powerhouse will be located about 1km north of the old one, with water diverted into the Wanganui River rather than the Amethyst.
The consent involves the clearance of 3.6ha of vegetation, a construction period of over 12 months and associated blasting noise. Land consent covers the construction of a 1.1km tunnel, access road and a 2.5km penstock, which will mostly be buried underground.