Auckland on cusp of water emergency as reservoirs left dry

The dry banks of the Upper Mangatangi Dam in the Hunua ranges.
The dry banks of the Upper Mangatangi Dam in the Hunua ranges. Photo credit: Simon Rogers/RNZ

Auckland is on the cusp of an emergency water crisis as it stares down the barrel of the region's worst drought in 25 years. 

Watercare is scrambling to secure extra water sources as its continues to plead with Aucklanders to conserve water inside their homes. 

It is a race against time as region's storage reservoirs continue to dry out and with no significant rainfall in sight, time is running out.

Last year marked a century that Hunua farmers Bruce and Dot Chipman's family have been on their farm, an hour's drive south of central Auckland.

They have kept up a tradition of handwriting daily rainfall records in stationery books that date back to 1962.

These records show annual rainfall on their farm averaging 1300 millimetres.

It has only dipped below 1000 millimetres five times in the past 60 years.

The first was in 1982, then 1983 and a third time a decade later in 1993. 

Mrs Chipman said annual rainfall was less than 1000 millimetres in 2018 and 2019 and this year was tracking to be the same. 

"There was no grass growing in the summer so there was a major problem for stock; we had to feed supplements to the cattle."

"Then in our home we're conserving water, because we're all on rain water not on town supply, so we're very careful and don't waste it."

The dry spell is made all the more serious because - according to the Chipman's records - the Hunua region missed out on about 350 millimetres of rainfall last year.

Mr Chipman spent his COVID-19 lockdown raking out deep cracks in his front lawn and said the ground was so dry a 25-year-old rimu tree recently died on the property. 

The rolling hills in Hunua are currently tinged with bright green grass but those who live locally know it is a very different story beneath the surface. 

Driving 30 minutes up the road, the dry, exposed walls of the Upper Mangatangi Dam starkly shows just how empty the city's water reservoirs are. 

The dam is one of nine water storage reservoirs in the Waitākere and Hunua Ranges that supply about 60 percent of Auckland's water supply. 

Water levels in the reservoirs have teetered around 45 percent full for months but dropped to 43 percent this week. 

Much has been said about just how serious this is for the wider region, but Watercare Hunua headworks operations controller James Talbot puts it best.

He is on the ground - day in and day out - working in the forest around the reservoirs.

"I've had a few people come to me and ask me is the situation being overhyped by the media and the message from me personally is absolutely not."

"We are definitely staring down the barrel of a potentially very serious water shortage situation."

The past few months have been the driest on record for Auckland; its water reservoirs dropping below halfway full for the first since the 1994 water crisis.

Just this week the water company used emergency powers under the Resource Management Act to draw a further 15 million litres of water a day from the Waikato River.

That brought the total daily pull from the Waikato River to 165 million litres. 

Watercare is also building a new reservoir in Pukekohe and will bring the Hays Creek Dam back into action by August.

But time is running out and all these projects will only secure a very small fraction of the more than 400 million litres of water Aucklanders use every day. 

Watercare set a target of 410 million litres or less a day, but Aucklanders exceeded it three times last week.

Residents were being asked to reuse water where possible and only run the washing machine or dishwasher when they were full. 

But keeping showers to four minutes or less was by far the most effective way to keep water consumption down.