The Cabinet will today consider a range of measures to ease the tight winter power situation despite Energy Minister David Parker dismissing the warnings of those he called "doomsayers" who were raising the threat of rolling blackouts.
The country faces tight winter supplies, with lake levels falling last week to just 50% of average for this time of year - the lowest since the last power crisis in 1992.
Civil Defence chiefs on Friday urged the Government to implement an energy savings campaign early, and power companies have also raised concerns.
Mr Parker said a general conservation campaign had been prepared and was ready to proceed if needed.
It would have been premature to begin the campaign any earlier.
"Campaigns become less effective over time and should not be started too soon.
"Two weeks ago, I said that without further rain or other remedial measures, a campaign was likely to be required in around three weeks.
"That timeframe remains correct, and further decisions on that can be expected."
Options included negotiating with major industrial electricity users to buy back power; Contact Energy investigating whether a further unit at New Plymouth could be recommissioned; advancing the commissioning date for Mighty River Power's geothermal plant at Kawerau, and legislation for the temporary lowering of the minimum lake level for one or more of the lakes.
Mr Parker said rainfall this winter was forecast to return to normal levels.
"I repeat that predictions by doomsayers that the lights are expected to go out as a result of low lake levels are wrong."
Electricity lines business Aurora Energy has been using "ripple control measures" on water-heating during peak load times, though Delta network services manager Lindsay McLennan said it had been used less than four hours a day.
Local lines companies "ripple control" the water-heating of customers with a certain meter connection, switching off electricity to their hot-water cylinders during peak times.
It is usually used about 40 days a year.
Mr McLennan said the level of energy use for the weekend would not be known until today.
Raineffects hydrologist Dave Stewart, of Dunedin, said yesterday rain over the weekend had helped fill hydro-electricity lakes, and the situation could be improving.
There had been "notable" rises at Lakes Te Anau and Manapouri of about 0.2m, while levels at Lakes Wanaka and Wakatipu had become steady, rather than continuing to fall.
There had been no sign of improvement at Lakes Tekapo and Pukaki, and other lakes had levelled off, rather than dropping.
Further north, heavy rain around Lake Taupo meant rises were expected there.
Mr Stewart said storms were forecast for later this week.
"If we get more rain soon, it may well be a sign that things are turning round."
Rain had brought Lake Manapouri from "low" to "main" range, giving Meridian Energy some flexibility, but company spokesman Alan Seay said while the increase would "keep the wolf from the door, it won't save us".
By David Loughrey with NZPA
