Contact Energy is apologising for environmental damage in the Central Plateau for the second time in two years.
In December 2020, it was convicted under the Resource Management Act and fined $162,500 for sending 15,000 cubic metres of soil laden with geothermal fluid into the Waikato River just above Huka Falls.
The company apologised and the judgment said the company had failed to heed its own alarm system, which would have warned it of the impending spill.
Then in February 2020, a routine spray programme at Torepatutahi Wetland was carried out under the agreed terms of Contact Energy's resource consent and with sign-off from the Waikato Regional Council.
However, 1.1 hectares of vegetation within the 30-hectare wetland was accidentally killed during the spraying operation.
Located off Broadlands Rd, the 4km long wetland is part of the Torepatutahi Stream that flows into the Waikato River at Valley Rd, about 6km south of Reporoa and 32km northeast of Taupō.
The upper reaches of the Torepatutahi Stream are known as Deep Creek, with the stream running through a towering 2km-long ignimbrite canyon.
The wetland is owned by Land Information New Zealand (Linz) who lease the land to Contact Energy. A Linz spokesperson said since 2014 Contact Energy had been restoring the wetland as part of the consent conditions for the Ohaaki Power Station.
The spokesperson said that in December 2020 Contact Energy contacted Linz advising they had received a complaint following weed spraying nine months earlier which had resulted in over-spraying.
Contact Energy head of generation, geothermal, John Clark said they were alerted to the environmental damage of the Torepatutahi Wetland in December 2020 by Ngāti Tahu-Ngāti Whaoa Runanga Trust, and Fish & Game Eastern Region.
Since 2014, Contact Energy had planted 15,000 native seedlings and undertaken animal and weed pest control, including clearing crack and grey willows. Clark said they were proud of the work done so far and apologised for the unintended outcome of the February 2020 spraying.
He said Contact Energy was committed to improving the biodiversity and the overall health of the wetland. That included a weed-spraying programme roughly every five years targeted at crack and grey willows and other noxious flora to enable native trees and plants to grow and thrive.
The herbicide used was green glyphosate 510, used for the control of most annual and perennial grasses and broadleaf weeds, including willow.
"We don't like to see people in the local community upset. There was no intention to cause harm to the wetland or the flora and fauna," Clark said.
Ohaaki-based Ngāti Tahu-Ngāti Whaoa Runanga Trust chairman Roger Pikia said the iwi was extremely disappointed and eagerly awaited the result of Waikato Regional Council's investigation.
"We view all of our waterways and wetlands as a taonga that are vital to what remains of our fragile ecosystem."
He said that as a minimum, iwi would expect the occupier to invite Ngāti Tahu-Ngāti Whaoa, as mana whenua, to co-design and approve their pest and weed management plans "to ensure this type of disaster is avoided in the future".
Fish & Game New Zealand eastern manager Andy Garrick said the Torepatutahi Wetland and stream was the most significant wetland within the Reporoa Valley for gamebird habitat (breeding and rearing) and was a noteworthy site for endangered bird species.
He said the wetland had high botanical value and was a very important component of the upper Waikato River trout fishery.
"Fish and Game looks forward to the outcome of council investigations, and in particular any decisions or recommendations relating to restoration of the wetland's biodiversity and habitat values."
Waikato Regional Council's incident response acting team leader Robert Isaac said there were limitations on what the council could say as the matter was subject to an ongoing investigation.
Isaac said they were concerned about damage to the wetland and late last year the regional council sent a wetland ecologist in to survey environmental damage. The report has not yet been completed.
Isaac said regional council staff has also attended and conducted an investigation of the site.
"As our investigation is ongoing, no decision has been made regarding culpability or any possible sanction. We don't have a firm timeline for this investigation to be completed at this stage, as it is one of a number of environmental incidents under inquiry."
Clark said Contact Energy was committed to good environmental practice.
"We are aware of the impact our operations can have on our surroundings and are committed to ensuring our activities are respectful, sustainable and not damaging to the environment or to the people who treasure and connect to it."
Three weeks ago Contact Energy met with Ngāti Tahu–Ngāti Whaoa Runanga Trust, and with Fish & Game to discuss their concerns and the restoration approach.
Clark said Contact Energy would continue to meet with Ngāti Tahu–Ngāti Whaoa Runanga Trust to discuss and establish next steps in the restoration of the wetland.