Higher power prices or even blackouts are a possibility if the country doesn't get some heavy rain over the next few months.
Low levels at our hydro lakes and a dry La Niña weather pattern are putting real pressure on the country's electricity supply.
The tide is certainly out at Lake Pukaki. Storage levels across the South Island's hydro lakes are around two-thirds of where they'd normally be at this time of the year, with low rainfall over the past four months.
"Just 68 percent of normal rainfall at Aoraki-Mt Cook. And that's near the all-important Waitaki catchment. So you get an idea that it's been quite dry across the South Island," says NIWA meteorologist Ben Noll.
It's partly due to a La Niña weather pattern, which causes dry conditions in the central South Island.
"This event now has been going since October 2020. So we've seen six-eight months of La Niña conditions," Noll says.
Transpower says we don't need to worry yet. But energy analyst Bryan Leyland says power companies have already ramped up non-hydro generation to try and keep up.
"Huntly's running flat out on coal. Fortunately, they brought a lot of coal in over the last few months, they've got enough coal and they're running flat out. Geothermal stations are running flat out. The gas-fired stations don't have enough gas by a long way," he says.
That's driving up the wholesale price of electricity, increasing costs for large manufacturing companies.
It's also putting pressure on power retailers Nova and Mercury - the first to pass on increases to consumers - with others likely to follow.
"The first thing that should be done, and it should be done right now I think is ask the public to conserve electricity. The Government has decided not to do that, and I think they're wrong," Leyland says.
The aluminium smelter at Tiwai Point is reducing its consumption until the end of May.
But the potential threat of blackouts remains, with the dry patterns forecast to stick around for at least the first half of winter.