Weather: Auckland rain makes little difference to water supply levels

The much-needed downpours over the weekend have made almost no difference to Auckland's dams.

Auckland's water supplier, Watercare, welcomed the recent rain but says the drought is far from over with the city's water storage dams still severely depleted.

Heavy, squally showers delivered 59mm of rainfall in the Hūnua Ranges – home to the four largest dams – and 21.5mm in the Waitākere Ranges.

But the rain saw the total water storage level in the city's dams rise less than 1 per cent - from 45.8 per cent to 46.5 per cent.

Watercare chief executive Raveen Jaduram says every drop of rain is welcome but warns the weekend's weather did not alter the overall drought picture.

"We need consistent rainfall over many months to make a real impact on our dam levels," Jaduram says.

"The weekend rain brought us just two days' grace, so we're still facing the possibility of water restrictions."

In the last month, the Hūnua Ranges have received a total of 62mm, compared to a historical average of 135mm. The Waitākere Ranges have also had less than half the usual amount of rain.

Residents in the drought-hit region are still being asked to conserve water as last month the total volume of water stored in the region's dams dropped below the halfway mark for the first time in more than 25 years.

Watercare is continuing to urge Aucklanders to take up the four-minute shower challenge and avoid outdoor use.

"Lots of small changes in behaviour, like deferring water blasting makes a real difference," Jaduram says.

"We know that because yesterday everyone stayed inside because of the rain, water use fell by 20 million litres across the region. Imagine if we could do that every day."

More rain showers are forecast over coming days, but indications are this is likely to be much less than normal for this time of year.

Watercare is continuing with a drought awareness campaign, which includes radio and digital advertising and social media messaging. Cutting shower times from eight to four minutes would reduce water usage by 80 million litres a day.

Downpours in Auckland around midnight caused flooding inside a house in Lochiel Rd in Remuera as well as on Mt Eden Rd and in Māngere.

MetService meteorologist Rob Kerr said between 10pm yesterday and 1am today a band of heavy rain brought downpours of 15-25mm in just one hour to parts of the city. Just 6mm an hour is considered heavy rain.

Drought-stricken Northland also received a decent amount of rain - with Kerikeri getting 45.6mm, mostly between 10am and 10pm yesterday. However, Whāngārei only saw 15mm and Kaitāia barely got 11mm.

"We know Northland is obviously pretty dry and in need of some rain and hopefully this will bring some relief at least to those empty water tanks up there," says MetService meteorologist Tom Adams.