Mapping today by fire services show yesterday’s bushfire in Otago burned more than 4600 hectares of mainly tussock and scrub, larger than the 2700 hectares estimated last night.
Fire and Emergency Incident Commander Graeme Still told media this afternoon the fire near Middlemarch is now contained, but mapping revealed about 4664 hectares of land was affected.
About 1100 hectares of the area is conservation estate, Te Papanui Conservation Park, and most of the rest is owned by the Dunedin City Council. A small amount of land, including the Meridian wind farm, is in the Clutha District.
Mr Still said while there were still hotspots active, mostly around the western edge of the fire, its spread had slowed down. Mr Still said infrared camera assessments tomorrow will help crews find their locations.
When conditions improve, ground crews will begin to tackle hotspots which are still smouldering and this work could be prolonged, he said.
Mr Still said one shed was destroyed, but crew were able to prevent damage to one house and the wind farm.
It is not possible to confirm whether any other structures have been damaged until the conditions improve enough to allow aerial inspections to resume.
Low cloud on the Lammerlaw Ranges has restricted full aerial reconnaissance today, but 15mm of rainfall has fallen overnight which “helped [firefighters] immensely”, Mr Still said.
He said there were plans in place before the fire broke out, which allowed crews to respond "very quickly".
Mr Still said the fire was spreading at a rate of 1.5km/hr yesterday because of the hot and windy weather, compared to typical speeds of 300m/hr.
He said yesterday's winds of up to 100km/hr made it impossible to put resources in front of the fire front for most of the day.
Mr Still said investigations into the cause of the fire will start tomorrow, but the fire was not being treated as suspicious at the moment.
“We don’t have any information about possible causes at this stage. We’re keeping an open mind,” he said.
Dunedin Mayor Aaron Hawkins said he continued to urge Dunedin residents to voluntarily conserve water.
The conservation park, where the fire started yesterday morning, protected 60 per cent of Dunedin's water catchment area.
The fire was near the Deep Stream reservoir, Dunedin’s primary water source.
The fire has burnt through 75 per cent of the Deep Stream catchment.
Group Manager of Three Waters Tom Dyer said Dunedin City Council would not take water from this reservoir near the fire as a precaution. This was due to fire retardants and ash getting in the water.
Mr Hawkins said the council was waiting on formal confirmation tomorrow that water from Deep Creek, another key reservoir, was safe.
Smoke from the fire affected a large area of South Otago yesterday. People who were sensitive to smoke were advised to stay indoors with their windows and doors shut, and to turn off air conditioning.