Last week’s variable weather conditions have revealed the impacts of climate change across Central Otago, and the prospective future for the activities that shape the region. Aspen Bruce reports.

Central Otago District Mayor Tim Cagodan says recent storms are evidence of climate change.

‘‘Around 2010 we had Bodeker Scientific look into what the effect of climate change would have on Central Otago. They said we could expect heavier downpours,’’ Mr Cadogan said.

He referred to last week’s overflow at the Omakau wastewater treatment plant as an example of the impacts of heavier downpours.

Originally built in 1965, the plant embankments had not been breached until 2017.

Since then, due to heavy localised downpours, the plant had experienced two overflowing incidents with wastewater spilling into the Manuherikia River.

Omakau and Ophir residents have remained on a Boil Water Notice and Naseby is on a Conserve Water Notice, since the incident on July 19.

No drinking . . . A boil water notice was issued for Ophir and Omakau due to flooding in the area on Tuesday.

Bodeker Scientific findings were projected to actualise closer to 2040.

‘‘Here we are in 2022. While there is other factors that come into it, like El Nino, when looking at the broader patterns, we can expect less snow and snow pack on the hills. That snow is significant in providing irrigation throughout our Central Otago community. That is a real economic threat to our region,’’ Mr Cadogan said.

The rising snowline could see regional snow-based activities greatly modified in less than 100 years due to fewer snow events and inconsistent colder temperatures.

Glacial reduction observations in Mt Aspiring National Park, have revealed “smaller glaciers, which people are familiar with now, might not be around within the century,” University of Otago School of Geography lecturer Dr Todd Redpath said.

He said glaciers relied upon seasonal snow accumulation throughout winter, followed by moderate temperatures in the summer, but inconsistent cold weather may disrupt this accumulation.

Dr Redpath referred to Dr Jordy Hendrikx’ published work “The potential impact of climate change on seasonal snow in New Zealand: part I—an analysis using 12 GCMs” from July 2012, as the most recent research into future seasonal snow affects.

Based on those research findings, 12 future scenarios are predicted.

The worst case scenario shows that by the 2040s, at elevations of 1000m, we could see as much as a 44% reduction in snowfall.

“When we consider the elevation where snow duration exceeds three months, we see a rise in this elevation from 1550m in the 1990s, between 1550 and 1750m by 2040s, and 1700 and 2000m by the 2090s,” the report concluded.

Flooded . . . Mark Halkyard, of Alexandra crosses the Omakau bridge yesterday afternoon. The bridge was closed after the Manuherikia River breached its banks causing road closures in the Omakau/Ophir area. PHOTO: SHANNON THOMSON

Protect Our Winters (POW) board member Marian Krogh said the shorter seasons, rising snowlines and less predictability, would have an impact on the snowsports industry. “July school holidays are the busiest time for local skifields. Over the years, sometimes they haven’t been able to open in time due to lack of snow — that’s big for the industry,” Ms Krogh said.

Treble Cone ski area manager Ewan Mackie said he recognised the industry is simultaneously vulnerable to climate change, while being a significant contributor to the causes.

“Our long›term thoughts are that our very existence is in peril as temperatures increase and we simply run out of snow. But in the short term, we’re already seeing increasingly severe weather; high winds, massive storms, too much snow, not enough snow. None of this is new by any means, but it is becoming far more extreme and more frequent,” Mr Mackie said.

In a CODC report, waste was identified as Central Otago’s major contributor to carbon emissions.

CODC Mayor Tim Cadogan said the report showed 55% of waste in landfill bins was greenwaste such as food scraps.

This was consistent with what New Zealand ski fields observed when auditing its carbon emissions in 2021.

As a result, Cardrona and Treble Cone removed landfill bins to reduce waste and encouraged customer awareness around waste habits. This also extended to eliminating single use packaging, seeing plastic bottles replaced with glass and cans across both mountains in 2021.

To increase community awareness around other practical climate change solutions, POW hosted an event at Cardrona last Saturday. The day involved a scavenger hunt and finished with dozens skiing under the McDougalls chairlift at 1pm.