Cyclone Gabrielle 12 months on: Redclyffe switched on, but what’s the future?

Announcements about the future of the Redclyffe Power Station, which Cyclone Gabrielle flooding cut power to much of Hawke’s Bay and the Gisborne region, can be expected within the next two months.

But practicalities make relocation unlikely, with station and national grid operator Transpower recognising that with only one comparable loss of supply in its near-century history - that of the Hawke’s Bay earthquake in 1931 - the flood was a particularly rare event.

In a report on the event and the recovery, Transpower says: “This was a ‘force majeure’ event, with the root cause of the loss of power supply to the Hawke’s Bay and Tairāwhiti regions being the RDF 220 kV bus tripping due to flooding. The impact of this incident was a total loss of supply to Hawke’s Bay-connected customers Unison Networks (Unison), Eastland Network (Eastland) and Pan Pac Forest Products (Pan Pac), affecting approximately 92,000 consumer connections.”

The focus from when the lights went out at 7.39am on February 14 last year went on re-establishing supply to emergency services, then to get power back into residential and commercial areas - greeted by clapping and cheering in the streets as the first areas benefited, five to six days after the cyclone.

Transpower general manager National Grid delivery Mark Ryall, who along with CEO Alison Andrews visited the site with Deputy Prime Minister Graeme Robertson a few days after the cyclone, says that while most of the 92,000 had supply reconnected in nine to 10 days, it was five months before Redclyffe Station was “back to its normal configuration” and another month before it had “normal” levels of protection.

The flooded Redclyffe substation, responsible for much of Napier and Hawke’s Bay’s power outage. Photo / Warren Buckland

By last week, restoration of the station had cost about $7 million and another $4m had been spent at Whirinaki, which had had some improved protection stemming from Cyclone Bola inundation 35 years earlier, such as the elevation of the control room - “that had all the brains” - to second-floor levels, hopefully out of reach of a new event, Ryall said.

But all the while there was the need to get the station functioning again, with a fortuitous availability of replacement componentry able to be moved on-site as soon as the clearing of silt and other debris from the flooded Tūtaekurī River and surrounds could be cleared, an experience which now forms part of the next chapter, the resilience and protection of the site against similar forces of nature.

“We will be in a position to update the public on our thinking in the next two months,” Ryall said, highlighting the extent of new infrastructure that would be needed if it were decided to relocate.

Unison’s general manager commercial and Cyclone Gabrielle incident controller Jason Larkin says that in terms of the weather, the company was well-prepared, moving crews and equipment ahead of time into different areas to make sure as much cover as possible could be given to the outages that were anticipated.

The loss of that national grid supply was not anticipated and “the big sign” of something as severe was when power was lost at the network’s own headquarters in Hastings.

The company has about 400 employees in Hawke’s Bay and a year afterwards, Larkin marvels at the extremes crews went to restore supplies, including some staff who had lost their own homes.

There were some lesson from Unison’s own experience with the mid-2016 loss of supply to hundreds of properties in the Rangitīkei region between Napier and Taupō, when snow downed poles and lines universally and all but destroyed the supply infrastructure.

While electricity has been restored around Hawke’s Bay after the calamity of Cyclone Gabrielle, it could be the end of this year before its network is “completely rebuilt”, he said.

Doug Laing is a senior reporter based in Napier with Hawke’s Bay Today, and has 50 years of journalism experience in news gathering, including breaking news, sports, local events, issues, and personalities.