City folk asked to watch water use

Photo / Christine Cornege

City-dwellers are being asked to save water around the home after three months of record-dry conditions.

Aucklanders need to wash full loads of clothes and turn off the taps when they brush their teeth to make sure there is enough water in the lakes next summer to supply homes and businesses.

Dams in the Hunua and Waitakere ranges, which supply most of Auckland's water, are at 61.9 per cent of normal levels - 6 per cent lower than usual for this time of year - following the driest three months recorded in the region.

Just 56.6mm of rain fell at Auckland Airport in January, February and March - the driest quarter since records began 50 years ago.

So far 28mm has fallen in April.

At the same time, people living in Watercare Services' supply area, from Papakura to Orewa, have begun using more water than usual.

Watercare networks manager Mark Bourne said water use was 5 per cent higher than usual for this time of year, probably because of outdoor activities such as people watering their gardens.

The result was that lake levels were falling, when they would normally be starting to fill as winter approached.

Mr Bourne said that since February Watercare had been taking as much water as it could from the Onehunga underground reservoir, and its Waikato treatment plant was also now running at maximum capacity.

He said the company was trying to leave as much water in the lakes as possible for next summer.

"What we are a little concerned about is if this really unseasonably dry weather continues into winter ... the lake levels coming into next summer will be significantly down from where they would normally be."

While Aucklanders are being urged to cut back water use around the home, a ban on using hoses and sprinklers has been spreading throughout drought-hit Northland, and the Whangarei District Council this week imposed restrictions.

Official drought conditions have been declared in the Northland region, Rodney, Franklin, Papakura, Manukau and Waikato.

The Bay of Plenty, Otago, South Canterbury and Mackenzie Country are also very dry.

The weather pattern that kept the dryness going is breaking up. But forecasters say it will be some time before rain restores parched soils to normal.

Niwa climate scientist Georgina Griffiths said near-normal rain was predicted for the North Island north of Taupo for April, May and June.

"We are over the worst of it [the drought]," she said.

"Even if we get that near-normal rainfall, which is forecast, the outlook [is for] soil moisture remaining in the lower third ... [in other words] below normal," she said.

Martin Smith, who is president of water industry group Water New Zealand, said the drought had highlighted the need to manage demand for water and plan ahead for new sources to supply a growing population.

He said cities where people had metered water, such as Auckland, tended to use less even if they did not pay for their water by volume, because they could see how much they were using.

But many cities did not measure what was being lost between the reservoirs and homes and businesses.

"New Zealanders need to start changing their attitude about water ... it is not freely available," he said. "We are blessed with an abundance of the stuff, but it is about getting that water in the right place at the right time."

Auckland's big dry

* Dams: 61.9 per cent full, 6 per cent lower than normal.

* Water use: 5 per cent higher than normal for this time of year.

Aucklanders used 392 million litres on Thursday, 18 million more than usual.

Waikato water treatment plant and Onehunga groundwater reservoir: Running at full capacity.

* Climate: Driest January, February and March on record.

* Forecast for the next 3 months: Near-normal rainfall north of Taupo.