A destructive wildfire that has cut off a southern community and stranded scores of motorists started at a campsite on the shores of Lake Wakatipu.
About 150ha of native scrub has been destroyed after the blaze took hold before midnight. Efforts are now turning to control the fire as strong winds are forecast in coming hours.
Otago deputy principal rural fire officer Jamie Cowan said it was too soon to say what had caused the wildfire but it appeared to have started at a campsite at Rat Point despite a strict outdoor fire ban in the region.
Eight helicopters and 50 ground crew from across Otago were now trying to contain the blaze that continued to burn out of control on steep, inhospitable lakeside terrain.
An investigation would start tomorrow into the cause.
Glenorchy has borne the brunt of the destructive blaze with power and road access cut off. About 1km of powerpoles and lines have been incinerated. A water taxi service is ferrying those unexpectedly stranded in the tiny settlement.
At this stage the fire was expected to burn for the next three to five days.
Scores of stranded motorists were forced to spend a rough night in their vehicles after the Glenorchy-Queenstown Rd was suddenly closed.
Residents of the small communities at Bobs Cove and Closeburn Station were put on alert early today as firefighters tackled the lakeside fire from the air and on the ground.
At this stage the fire front remains 2.5km away from the nearest homes.
Aerial mapping is under way to work out the extent and progress of the massive blaze, which spread across 50ha of scrub and trees in the first 11 hours. It has since claimed a further 100ha.
A motorist who came across the fire early this morning said up to 50 vehicles lined the Glenorchy-Queenstown Rd.
Jonny James was forced to hunker down in his vehicle for the night, one of many drivers heading back to Queenstown along the scenic route whose journey was brought to an abrupt halt by a wall of fire.
"I headed down the road and I could see a massive orange cloud over the hills," said James.
"She was raging on both sides of the road.
"It's definitely the biggest fire I've seen in my life."
Between 40 to 50 vehicles were parked along the main road unable to get to Queenstown.
Those who spent an uncomfortable night in their cars were this morning reviving weary bodies at the local hotel, drinking coffee and waiting for updates online to find out when they could get out.
Cowan said the fire began beside the lake about 10km west of Sunshine Bay around midnight and had now crossed the road and spread uphill and to the east, burning through thick vegetation.
The fire had spread across 50ha on Jessie Peak above Rat Pt.
Cowan said at daybreak the fire had reached the ridgeline at the top of the slope above the road and its progress has slowed.
That had reduced the threat to communities, with the nearest houses about 2km away.
"We are hitting it hard with all the resources we have available because the forecast is for winds to pick up this afternoon, with no rain expected before midnight tonight," Cowan said.
Fire crews from Glenorchy, Arrowtown, Queenstown, Luggate, and Alexandra had been brought in to tackle the fire.
Residents of Bobs Cove and Closeburn Station have been put on standby but at this stage no evacuations had been ordered.
The Glenorchy Rd would remain closed from Bobs Pt to Mt Creighton until this afternoon.
Motorists would not be allowed back on the road until the road and slopes above were inspected to ensure no rocks or debris had been dislodged by the fire.
At this stage there was no indication how long it would be before power could be restored to Glenorchy.
Cowan said that once the active fire had been extinguished near the roadside, the Glenorchy Rd would be assessed by engineers to ensure it was safe before it could be reopened.
Once that happened, crews could get access to start repairing the Glenorchy electricity supply.
The MetService said strong winds were forecast and no rainfall is expected until tonight.
- Additional reporting: Otago Daily Times