Firefighters are confident a large vegetation fire burning on Tiwai Peninsula, near Bluff, is under control.
The fire, which began on Thursday, was burning over 1200 hectares of scrub and valuable conservation wetland, with a perimeter of 18 kilometres.
Up to 40 firefighters were at the scene on Thursday, as the fire grew in size due to higher temperatures and winds.
Two crews remained on site overnight to monitor the blaze.
The fire poses no immediate threat to people, homes, the Tiwai Point smelter or the Tiwai Bridge, a spokesperson for Fire and Emergency New Zealand (Fenz) said.
Fenz incident controller Hamish Angus told Morning Report on Friday the outlook was "pretty good".
"We just had a bit of a look up there this morning and,, things look pretty contained and controlled. We haven't got any visible flames at the moment, so things are looking really good."
It was too early to determine a cause just yet, he said.
"We've got a couple of fire investigators coming out here this morning,, so I'm sure we'll get to the bottom of all of that."
Cooling pumps for the aluminium smelter were threatened by the blaze, but they had been so far protected.
"Tiwai is well used to this - certainly this isn't the first fire down here, so they do have other options [for] generation… It wouldn't have been a catastrophe, but certainly one of their priorities today is supporting the power contractors to get in there and get the lines connected to pumps."
The primary job now for firefighters would be establishing a "cold perimeter" and knocking out any heat sources before the wind picks up, forecast for later in the week.
"It's pretty much time now for the real grunt work to start."
Fenz Assistant Area Commander and incident controller Bobby Lamont said yesterday the 2022 Awarua Wetlands fires had played a big part in yesterday's response.
"Experience has certainly played a key part in scaling up our resources a lot quicker.
"We got resources out here not long after the fire was first reported and they've made some really good grounds to protect the smelter and then to get on top of the fire today," he said.
Fenz volunteer and professional firefighters as well as Department of Conservation (Doc) crews had been deployed from Dunedin and the wider Southland region.
"Crews are still working pretty hard to contain it ... we're monitoring their work rates constantly," he said.
"It's quite arduous through this terrain ... quite scrubby and undulating terrain for them, so it's quite taxing work on the crews."
The firebreak protecting the Tiwai Smelter had also been strengthened, he said.
"[We're] increasing the burnt fuel that's around it and making sure that all the hot spots on those flanks [are out, so] if we do have a wind change that could go towards the smelter, there's nothing there for it to burn.
"Thankfully, the northwest wind is pushing the fire away from the smelter."
A large part of the fire's right flank had reached the south beach area before noon.
"At this stage, the plan is to push it to the beach where there is no fuel for it to burn.
"The weather is playing its part for the moment, which is good."
AAC Lamont said while the fire passed beneath the smelter's high tension power lines and smaller supply lines, they had all been inspected and deemed safe.
MetService meteorologist Katie Hillyer said no rainfall had been recorded in the Tiwai region for the past month and only isolated showers were expected in the near future.
There was no immediate indication of how and why the fire started, but fire investigators would be on the scene once it was safe.
New Zealand Aluminium Smelters external affairs director Simon King believed there was no immediate danger to the smelter or staff and the plant remained in operation.
"We continue to monitor the situation and are in contact with emergency services and have offered any assistance they require."
The land surrounding the smelter was leased from and managed by Doc and made up part of New Zealand's Conservation Estate.
Part of the land also came under the Awarua Wetland Ramsar site.
Awarua rūnaka manager Gail Thompson said she was deeply saddened at the damage caused in such a short time.
Doc's Southland operation manager John McCarroll said Awarua Peninsula had considerable environmental value and it was a huge blow.
"Awarua has a significant number of biodiversity values and is used by a lot of wading birds for flocking and feeding, including the endangered Southern New Zealand Dotterel/Pukunui," he said.
"As well as the loss of wildlife, we've also lost assets such as predator-trapping infrastructure."
- By RNZ and Toni McDonald
