KEY POINTS:
The country has just four weeks before severe power cutbacks will be needed.
Only extensive rain flowing into the South Island's hydro lakes will avert extensive cutbacks - but signs are that wintery weather headed that way will drop snow, not rain.
In developments yesterday:
* Civil Defence chiefs met in Auckland and urged the Government to implement an energy-savings campaign early.
* Meridian Energy warned that any "glitch" at Huntly's thermal power station this winter would plunge the country into an electricity crisis.
* Genesis Energy chief executive Murray Jackson said the North Island's peak demand - between 6pm and 8pm each day - had to drastically drop in the next four weeks.
Hydro-electric stations usually produce about 70 per cent of the country's electricity, but they are contributing only 50 per cent at the moment.
That has caused a shift in dependency to thermally generated power this winter, all of which comes from the North Island, Meridian spokesman Alan Seay said.
He said Meridian was still optimistic that winter power shortages could be avoided, with one warning: "If Huntly falls over, we've got an instant code red."
Huntly's coal- and gas-fired station has a 1450-megawatt capacity, making it the largest-capacity power station in the country.
The South Island's Waitaki and Clutha power schemes have a combined capacity of more than 2500MW, but their main storage lakes (Tekapo, Pukaki and Hawea) are at about half the level they should be.
Mr Jackson said users needed to conserve energy wherever possible to prolong what little reserves were left in the South Island's lakes.
Limiting use of clothes driers, dishwashers and washing machines would be a good step, he said. People should also look to reduce their lighting usage by half.
"If this persists into July, then we'll have to seek more severe curtailment over peak periods in the North Island."
Mr Jackson said three days of foul weather running up the country from the Southern Ocean would put huge pressure on reserves and peak loads.
Civil Defence chiefs from all Auckland's councils met yesterday to discuss the crisis.
Civil Defence emergency management group chairman Derek Battersby described Auckland as "the boiler room" of New Zealand.
"Our country is in a fragile situation and if it hits us in the next few months, it won't bode well for New Zealand," he said. "We are looking for some comfort that the lights won't go out in Auckland."
David Reeve of Mighty River Power, which monitors hydro power supply, told the meeting the firm's focus was on encouraging people to save "because we don't want people sitting in the dark, in the cold".
Auckland Regional Council deputy chairman Michael Barnett said he did not think Civil Defence was over-reacting.
"I'm thinking of an exporter ... " said Mr Barnett, who is also Auckland Chamber of Commerce chief executive.
"Is he talking to his clients offshore today about his June-July deliveries and saying, 'You will have to wait until I see if the village generator is working that week'? That to me is a nonsense."
Auckland suppliers of power generators say concern in the business community about blackouts is reflected in the number of inquiries about generators.
"More companies are buying them as standby power in the event of emergency," said NZ Generator Hire sales manager Jim Stewart.
"All sorts of companies are looking at buying generators - a lot of IT firms cannot afford to have power down, especially companies with a lot of servers.
"People remember that during the Auckland CBD power outage a decade ago you could not get a machine. People know they have to have a backup."
But the two power companies responsible for the southern hydro stations were this week adamant current lake levels were nowhere near crisis point.
Meridian, which owns the Waitaki and Manapouri stations, said that although the lake levels were low, they were well above 1992 levels.
Lake Pukaki still had about 5m of water left before its lower limit was reached, Mr Seay said.
In 1992, NZ was forced into national power-cutting measures for several months.
Businesses switched lights off at night and households endured hot-water restrictions.
Contact Energy, owner of the Clutha stations, said power shortages caused by low lake levels were "very unlikely" this year.
"Certainly they're lower than we would have liked," said spokesman Jonathan Hill, "but we're working very hard to ensure the generation we have is enough."
