Waitaki hydro-electricity storage lake levels have bounced back after heavy rain, easing fears they were falling with winter approaching.
Mt Cook had 358mm rain over five days up until Wednesday, lifting the levels of Lakes Tekapo and Pukaki which feed Meridian Energy's eight power stations on the Waitaki system.
That followed an unseasonal dry spell since January, when Meridian's lakes were over-full and it had to spill water.
Inflows since January have been extremely low, at just 73% of average which, combined with low lake levels at Manapouri and Te Anau, raised fears New Zealand could enter winter with low hydro storage.
Electricity was flowing from the North Island to the South.
Meridian spokesman Alan Seay said Meridian had been prudently managing its generation through the Waitaki system as a result.
However, the situation had eased in the past week with heavy rain in the upper catchment.
Yesterday, Meridian's lakes were showing the start of an upward trend, after going down steadily since the start of February, as in-flows increased.
Yesterday, Lake Tekapo at 708.844m above sea level was 85% full and Pukaki at 530.342m was 88% full.
In terms of the average level for this time of year, Tekapo was 101% and Pukaki 98%.
"Both are close to average for this time of year, so we are in pretty good shape," Mr Seay said.
Another factor was the levels of Lakes Te Anau and Manapouri: if they were low, then Meridian had to use Waitaki to meet customers' needs.
Te Anau is 113% of average for this time of year and Manapouri 105%.
The recent heavy rain had put the lakes in better shape after the long dry spell since January.
Asked if that would continue until winter, Mr Seay said his experience of the past 11 years with Meridian was a "great bulk" of in-flows now occurred during autumn with northwest conditions.
"We will still be taking a prudent and responsible approach to managing the lakes," he said.
• The inflows into the headwaters of Lakes Dunstan and Roxburgh have doubled in the past five days, Contact Energy's market and dispatch manager at Clyde, Boyd Brinsdon said.
Until the recent rainfall, the lakes had been below their mean level for much of the year.
Lake Wanaka's level was steady at 277.2m yesterday, up from 276.5m on Sunday; Lake Hawea was at 344.4m, up from 344.15m on Sunday.
Little rain has been recorded in the past 24 hours but Otago Regional Council rain gauges show in the past week, there has been 57.4mm of rain at Makarora, 175mm at Cascade Hut and 154mm at Albert Burn.
