Water shortage: Auckland needs twice as much rain to top up dams

Mangatawhiri Dam in the Hunua Ranges during heavy rain last month. Photo / Watercare

By Liz Chen for RNZ

Watercare says August will have to be twice as wet as usual if Auckland's water supplies are to get back to a normal level.

A record dry start to the year meant the city's four main dams in the Hunua Ranges were only about 65.6 per cent full, while the historical average is 88.1 per cent at this time of the year.

At the start of July, Watercare called for people to use less water, suggesting showers be limited to four minutes.

However, on streets in central Auckland, the water saving message hasn't been getting through to everyone.

Kokila Ramiah, who was shopping with her 11-year-old daughter Shreesthi, said she didn't hear about the water shortage in the city.

"It's a bit difficult with children - they get in there [the shower] and never come out," she said.

Among those who did know about the shortage, like mother-of-five Andrea, they were not necessarily making changes to their water use.

"I mean we should be doing something differently. I think our biggest water use is probably clothes washing, dish washer and showers," she said.

"We should be a bit more careful about loads of washing, loads of dishes and things like that."

However, others, like Suzy, are more aware.

"I am aware of it and just being more careful. I'm not even using a dish washer every time."

Niwa meteorologist Ben Noll said the upcoming months are going to be wetter.

"For Auckland and Northland, it's looking like near normal rain fall for the August to October period. This outlook of wetter weather is good news as we can use it to top up the dams," he said.

However, after a very dry start to the year, there has been rain this winter but not enough to avert a shortage, according to Watercare's head of water, Roseline Klein.

"Aucklanders feel it has been raining, but from our standards, it hasn't been raining enough. July tracked below the historically average, so we've got a deficit we've accumulated over the past seven months now," she said.

"We haven't got the recharge we normally get in winter, and we're aware we only have one month of winter left."

Two years ago Aucklanders had a crash course in water conservation when dams were damaged by torrential rainfalls.

Klein said those lessons need to become an everyday reality.

"We really would like people to put in place water saving practice that they can sustain in long-term. It's a long-term situation that we'd like Aucklanders to be water-wise."

Watercare said people used 2.5 per cent less water in July than the previous month.

It said while people's individual actions might feel small, with 1.5 million water users in Auckland they all add up, and if everyone reduced their shower time by a minute, Auckland could save 18 million litres of water every day.

- RNZ