Outage creates opportunities at the Waipori power scheme

Trustpower turned a rare eight week shutdown at one of its largest power schemes into an opportunity to undertake major maintenance, overhauls and improvements.

Disruptive repairs to an ageing tunnel at the Waipori scheme, southwest of Dunedin, gave Trustpower the chance to tackle more than 60 other jobs on site.

“We knew it was going to be a major job to fix the tunnel, but when it became clear that an extensive outage was required, we decided to make the most of this rare opportunity,” says Luke Davey, Trustpower Project Manager.

“We pulled together close to 250 people from 40 companies to complete more than 18,000 hours of work on and off site.”

The Waipori scheme’s four power stations are in a narrow and rocky gorge, which plunges 165 metres over just four kilometres. With storage lake levels lowered for the outage, Trustpower used the window to inspect and test many of the scheme’s major structures, repair or replace aged equipment, and spruce up the stations to ensure the ongoing reliability of the scheme. Seismic risks were addressed to protect the environment, the power stations and the communities downstream in the event of an earthquake.

Trustpower, its consultants and contractors had to contend with a number of challenges once work got under way. The outage began in snow, sleet and hail, and the main public access road had to be closed for two weeks due to slips. An electrical storm took out some key equipment and then helicopters had to be called in to fight a wildfire threatening crucial assets.

Despite these disruptions, Trustpower’s staff dedication and strong relationships with its suppliers and partners ensured the large workload was completed on schedule, avoiding a series of smaller shutdowns in future.

“It is a testament to the team’s resilience and the impressive way everyone pulled together to get the jobs done,” says Luke.

Trustpower’s staff dedication and strong relationships with its suppliers and partners ensured the large workload was completed on schedule.