A mass rescue operation involving at least 110 people competing in an ultra-marathon event took place on Wednesday morning, as heavy rain caused the Arrow River to rise.

The Rescue Coordination Centre said it was first alerted to a developing situation following a beacon activation in Macetown, near Arrowtown at 1am.

Eight further personal locator beacons were activated soon after.

Operations manager Michael Clulow said six people had been flown to Queenstown Lakes Hospital and were suffering from mild hypothermia.

Clulow said communication was been established with the race management and RCCNZ were focused on finding out where people were, and what their support needs were.

The Herald understands the “call-out” from Search and Rescue has since been stood down as the situation is under control.

”At this stage the majority of competitors and staff have been accounted for and are safe at the Macetown Camp area,” Clulow said in an earlier statement.

He said the priority of the ongoing response was reconciling the number of people in the area and confirming they were safe.

”There is inclement weather in the area, and the six who have been evacuated so far were suffering from mild hypothermia.”

The Southern Lakes Ultra started on Sunday, February 19, and is a seven-day, six-stage race through the Southern Lakes in Central Otago.

In a statement on the race’s Facebook page, coordinator Emily Sutton said all runners were accounted for and safe.

“I am in great communication with multiple organisations and agencies and at this stage all athletes are safe, well and accounted for. Rescue operations NZ are sending individuals into Macetown to organise a plan,” Sutton said.

“Some runners have been evacuated out of the mountains and they are being cared for by crew and staff at Queenstown Lakes Hospital,” Sutton said.

In a statement on the race’s Facebook page, coordinator Emily Sutton said all runners were accounted for and safe. Photo / James Allan

Clulow said this was a complex response, and the centre was working closely with search and rescue partners and the race organisers to understand the needs of the people in the area.

Two trampers hiking the Macetown Trail were tenting down near the region’s checkpoint. First thing this morning, they spotted two helicopters going deep into the valley picking people up.

“It looked quite serious,” said Robin, one of the trampers.

“The conditions are terrible, you wouldn’t be able to walk the rivers this morning, they’re now up to our knees, whereas yesterday it was just at our ankles.”

The trampers from Matamata, Waikato said they were very lucky to be out of the valley, otherwise, they would have been stuck in their tents.

In a statement on the race’s Facebook page, coordinator Emily Sutton said all runners were accounted for and safe. Photo / James Allan

“I’d say hypothermia in all that rain would have been absolutely terrible.”

The rescue centre said there has been heavy rain in the area, causing the Arrow River to rise and the weather was forecast to remain inclement over the next 24 hours.

MetService this morning issued a heavy rain watch for Otago with a period of rain to fall from 8am until 11am. It said some heavy falls were possible.

In the alert it said rainfall amounts might approach warning criteria, especially in the east where the threshold for heavy rain was lower.

Macetown, located just north of Arrowtown, is an abandoned gold-mining town isolated from any nearby townships. It can only be accessed by 4WD vehicles.

Vehicles will travel across the Arrow River. There is a Department of Conservation campsite and some tourism companies do river crossings and adventure races through the area.

Nearby businesses have told the Herald it rained heavily overnight, although little was known about the rescue.

A helicopter spotted in Macetown, near Arrowtown, during a mass rescue. Photo / James Allan

Nomad Safaris run regular 4WD tours through Macetown.

To reach it, one must cross the Arrow River two dozen times. The safari company suspended its tours over the past couple of months because of the recent dry and dusty conditions.

Amanda Gatward-Ferguson, one of the owners, said the Arrow River could rise “really quickly” without warning, and was common when rainfall was experienced at the levels of last night.

”There’s a measuring point on the river. When it gets to a certain point, we don’t [operate],” she said.

The river isn’t navigatable by boat, according to Gatward-Ferguson, which leaves helicopters as the only remaining option to reach people.

Statement from race coordinator

Good Morning Everyone,

I would like to let you all know that due to weather conditions there is currently a rescue operation underway for participants and crew involved in Southern Lakes Ultra.

I am in great communication with multiple organisations and agencies and at this stage all athletes are safe, well and accounted for. Rescue operations NZ are sending individuals into Macetown to organise a plan.

Some runners have been evacuated out of the mountains and they are being cared for by crew and staff at Queenstown Lakes Hospital. These athletes are being well supported and are currently under observation.

If there is any concern individual families will be notified by me directly. As you will all understand this is a very stressful time so please hold off messaging directly.

I will continue to provide communication with you all where possible and I can ensure you that I am doing my absolute best to ensure the health, safety and well-being of these athletes remains our top priority.

Kind regards,

Emily Sutton

- More to come