A subcontractor suffered a serious leg injury while working at the Roaring Meg Hydro Generation site.
Emergency services, including two ambulances and a Queenstown-based helicopter, were called to the Kawarau Gorge site just before 10am yesterday, a St John spokesman said.
A man, aged in his 40s, received a serious cut to his leg in the workplace incident.
He was taken by helicopter to Dunedin Hospital where he remains in a serious condition.
Pioneer chief executive Fraser Jonker said ''this is devastating news''.
''This is an unfortunate incident and we are currently still investigating the circumstances.''
He confirmed the subcontractor had been working on a pipeline replacement at the site.
Mr Jonker said the company worked to stringent health and safety compliance standards.
All contractors were thoroughly inducted at the workplace and held their own health and safety plans.
WorkSafe New Zealand confirmed it had been notified, and the incident would be referred for investigation.
