Contact Energy is ruling out any major changes to its management of Lake Dunstan.
Contact Energy's Clyde Dam. Photo:
It comes in response to the announcement earlier this week by the Otago Regional Council that parts of the electricity giant's consent to operate Clyde Dam will be reviewed.
Every five years the council has a three-month window to notify Contact Energy of its intent to review consent conditions.
But it was a rare, and potentially unprecedented, step to actually act on the ability.
The council notified Contact on Tuesday, with just a day left in the three-month window.
The council would review conditions relating to the impact of the dam's operation on the Kawarau Arm of Lake Dunstan.
Lake Dunstan was formed at the confluence of the Mata-Au/Clutha River and Kawarau River by the damming of the Mata-Au at Clyde.
Since it was filled in the early 1990s, the lake had provided recreational amenity to the community of Cromwell.
But the Kawarau Arm had in recent years become a shallow, and at times smelly and dangerous mess, due to silt, that used to wash down the Kawarau River and onwards along Mata-Au, now being trapped and accumulating for three decades.
Last month, RNZ reported the council had issued an abatement notice against Contact over the Landscape and Visual Amenity Management Plan - basically the road map for how the Clyde Dam's effects on the Kawarau Arm would be managed.
The council's confirmation of a review followed pressure from community groups, who said the electricity giant was not fulfilling its obligations as a corporate citizen.
Contact said it welcomed the review and the opportunity to clarify the consent.
Contact Energy head of hydro generation Boyd Brinsdon said the root of much of the disagreement over the management of the Kawarau Arm was due to a lack of clarity.
File image. Photo: RNZ / Nate McKinnon
"I think part of our struggles - and I'll call them that - over the last couple of years is a lack of clarity over what those conditions require and are meant to do. So having more clarity for all parties, including Contact, as to what is required and what we do going forward is a good thing."
The Kawarau Arm was destined to become a braided river, it was just about managing how that occurred and what management of the process looked like, Brinsdon said.
"It's just a resolution about what can be added [to the consent conditions], consideration around native plantings, consideration of what other things we can do to improve and mitigate the transition from a lake to alluvial river environment," he said.
He ruled out larger-scale interventions, such as mechanical dredging of the Kawarau Arm.
"As Contact has said many times in the past, the practicalities of moving or managing close to a million cubic metres of sediment each year that arrives in the Kawarau Arm is just completely impractical," Brinsdon said.
"Our consents consider that and the hearings panel back in the 2000s acknowledged that. Their wording is very clear - the effects over the next 35 years, the terms of the consents through to 2042, will mean accumulation of sediment in the Kawarau Arm. The obligation on Contact, which isn't clear, is to manage only the visual amenity values of that.
"There's no consideration in our minds as to the removal of sediment because the scale of it is completely impractical to deal with through mechanical extraction, simply because even if a million cubic metres of sediment could be removed from the Kawarau Arm each year, where would it go? Where would you place it? And what would that look like? And the adverse effects of that would be substantially greater than they are today."
That would come as a blow to some members of the community who had been calling for dredging and removal of the sediment.
Otago Regional Council regulatory and communications general manager Richard Saunders said there was no timeframe for when the review would be completed.
It would be at least a month before the council had even made a decision on what, if any, public input there would be to the process.
Saunders conceded without pressure from community groups, such as the Lake Dunstan Charitable Trust, it was unlikely the review would have even occurred.
But the fact it was taking place was not an indictment on Contact.
"It shouldn't be seen as a reflection on Contact themselves," he said.
"What we're really seeking out of this process is absolute clarity for everyone going forward."
- RNZ omitted the word 'out' in the headline and it has now been updated.