Mercury is putting the finishing touches on its $90 million upgrade at its Karāpiro Hydro Station on the Waikato River.
The refurbishment project involved replacing all three of its generation units, one each year since work began in 2023.
The third and final unit is being tested and commissioned and is expected to join the other two units generating electricity for the country by September.
Mercury organised a special community day to celebrate the milestone with those living near the hydro station at Karāpiro.
Mercury Chief Executive Stew Hamilton, in his speech at the event, noted the support and patience of the Karāpiro community over the past three years.
Karāpiro community was treated to a tour of the hydro station as part of the community day.
“We are nearly there; we expect to have the final generation unit up and running in September.
“And very shortly we’ll be re-opening the road across the hydro dam, which I know is an important east-west route for many people in this district.”
Taupō MP Louise Upston, whose electorate includes Karāpiro, also attended the community day.
“I visited the hydro station during the early stages of its refurbishment and it’s great to return and see the project now complete.
“Investment in our electricity generation infrastructure is vital to ensure we can improve our capacity and security of supply.
“Upgrades which increase output without having to build new generation are a huge plus.”
Karāpiro Hydro Station Site Lead Kiel Adlam with a tour group inside the control room.
Waipā Mayor Susan O’Regan was also at the event. She said the Karāpiro Hydro Station was not just a vital part of the national electricity grid, it was also a part of the history of Waipā and a part of the district’s identity.
“This upgrade future-proofs an essential piece of infrastructure, and I know the community will be especially pleased to see the road across the dam reopened.
“It’s more than just a road – it’s a key connection for our local residents and for the thousands who come to Lake Karāpiro every year for business, sport, and recreation.”
Mr Hamilton said the Karāpiro Hydro Station has been helping to keep New Zealand powered for nearly 80 years.
“Mercury and others before us have invested heavily in maintaining the hydro station, and we want to ensure that legacy continues.”
Hydro Rehabilitation Programme Manager John Kennedy on top of one of the generation units with a tour group.
The upgrade will ensure the hydro station can continue to generate power for another 50 years.
Total installed capacity has moved from 96MW to 112.5WM. That increases average annual output by 32GWh, enough to power the equivalent of an extra 4000 average homes.
The station’s total average annual output is now 537GWh, producing enough electricity to power the equivalent of 63,000 average homes a year.
“This project is part of our long-term refurbishment programme to upgrade each of the nine hydro stations on the Waikato River.
“We now turn our focus towards planning to upgrade Maraetai I, Ōhakuri and Atiamuri.”
Mr Hamilton said work on these stations represents an investment of $550 million, thought to be the largest in New Zealand’s hydro history.