Southern hydro lakes have dropped to as low as 30% of their average energy storage but power companies are not yet concerned the levels will hit winter power supplies.
The recent dry spell affecting Otago and Southland meant there is less water going into the regions' hydro lakes.
Meridian wholesale market manager Mike Roan said lakes Manapouri and Te Anau were at 30% of their average energy storage for this time of year, while the Clutha catchment was at 65% and the Waitaki catchment (Pukaki, Ohau, Benmore, Waitaki, Aviemore) at 87%.
Those levels were not a concern, as there was "plenty of time" for weather events to hit the region and fill the lakes between now and March, Mr Roan said.
"There is plenty of energy when those events hit."
The Manapouri and Te Anau catchment was small compared with the Waitaki, so the low levels had less of an impact.
Meridian had reduced the generating level at Manapouri power station, in line with operating guidelines.
Contact Energy spokeswoman Janet Carson said the Clutha lakes had low inflows for the past two months, resulting in lake levels considerably lower than this time last year and a "little lower" than mean.
Wakatipu was at 309.61m above sea level yesterday, Wanaka at 276.75m and Hawea was at 343.49m.
Contact was drawing conservatively from Lake Hawea, which is not usual for the time of year, due to low inflows in the Otago catchment area.
However, although low, the levels were not an issue at this stage, she said.
