A dry Lower Nihotupu Dam in the Waitākere Ranges
A dry Lower Nihotupu Dam in the Waitākere Ranges

PartnersMay 15, 2020

Why Aucklanders must save 20 litres of water every day

A dry Lower Nihotupu Dam in the Waitākere Ranges
A dry Lower Nihotupu Dam in the Waitākere Ranges

A severe drought has forced Auckland Council to impose water restrictions for the first time in 25 years. Simon Day spoke to Watercare CEO Raveen Jaduram about why saving water this winter is essential. 

Over the past five months, when I pause on my (almost) daily run with my dog to take in the view from the top of the Waitākere Ranges, I’ve watched muddy beaches progressively form on the banks of Lower Nihotupu Dam. Through the long, dry summer, I’ve watched these beaches grow, then crack and turn into deserts as the dam’s water sunk lower and lower. Lower Nihotupu Dam is one of nine water storage dams in Auckland. Together, they’re only 44.8% full – significantly lower than normal for May.

This weekend, mandatory water restrictions will come into effect in Auckland for the first time in over 25 years (I’m sure the refrain “if it’s yellow let it mellow, it’s brown flush it down” rings familiar in the minds of many millennial Aucklanders). The water shortage is the result of 16 months of acutely dry conditions. 

Last year, January to July was the driest on record for that period in Auckland. Then, after relatively normal rainfall through spring, the stretch from November 2019 to April 2020 was also a record-breaking dry stretch. The dams have only received 37% of their normal rainfall this year.

“It is very unusual that you see such an extended and extreme dry run,” says Georgina Griffiths, Metservice local meteorologist, Auckland.  “You don’t catch up from that very quickly, especially on the back of the year that was 2019.”

Winter rainfall looks “boom or bust”, according to Griffiths. And while long-term rainfall is hard to forecast, current projections suggest a “normal” amount of rainfall for Auckland. 

“We need more than a normal winter rain to fix the problems in the lakes,” says Griffiths.   

So Watercare needs Aucklanders to make sacrifices to help the water storage dams recover as much as possible over winter. Stage one restrictions mean residential water users cannot use an outdoor hose or water blaster, and Watercare has the power to impose fines of up to $20,000 (although the organisation has said it is committed to an educational approach and has even created a Spotify playlist of four-minute songs – the recommended length of showers). 

The Spinoff spoke to Watercare CEO Raveen Jaduram about what the city’s residents need to do, and why it’s so important. 

The effects of the drought on the Lower Nihotupu Dam (Photo: Supplied)

How bad is the state of the dams right now?

It’s quite bad and getting worse. And the reason it’s bad is because the first four months of this year were the driest on record for Auckland. 

By itself, a dry summer is not so bad. But we’re in autumn now and still haven’t had much rain. The forecast for winter is for below-average to average rainfall, and spring is expected to be dry. That’s worrying.

Our water supply model relies heavily on us getting rain in autumn and winter, which we store and use over summer. So by the end of October, we need our dams to be at least 90% full. 

Given our dams are 44% full today, and we’re not expecting a wet winter, we could head into summer significantly below the 90% storage. It’s looking like our dams may only get to 65% full this winter. This could mean we have severe restrictions going into summer, and restrictions in summer are very difficult for everyone.

But if the dams are 65% full by the start of summer, it doesn’t sound like we are going to run out of water? If we’re not, why is this a problem?

Auckland will never run out of water thanks to our Waikato River and Onehunga aquifer sources. They produce around 170 million litres a day.  

But it’s all about supply and demand. The city uses a lot more than 170 million litres a day. At the moment, homes and businesses are consuming around 420 million litres a day. And in summer, demand can skyrocket to 568 million litres a day. We cannot meet that level of demand if we start summer with dams that are 65% full. 

What are the restrictions that you’re asking Aucklanders and businesses to make at stage one? 

Restrictions highlight the seriousness of the situation. They send a clear signal to Aucklanders that the drought is real and the time to save is now. 

From May 16, people will not be able to use hoses or water blasters at home. And there are further conditions on commercial and non-domestic use. They’re not allowed to operate car washes, for example, unless they use recycled or non-potable water. 

But its not all about restrictions – that’s an important point to get across. We’re also asking people to make savings inside their homes – around 20 litres per person per day – and we’re asking businesses to make savings of at least 10%. 

On Watercare’s side, we’re working to bring two former water sources – a dam in Papakura and a bore in Pukekohe – back into service. And we’re expanding the Waikato Water Treatment Plant. These initiatives will see the volume of water available increase by 36 million litres a day. 

What we really need though, is rainfall. Because this is a rainfall issue. 

What decides whether we move to stage two restrictions? 

We have dam storage level triggers and they vary depending on what season we are in. Stage two restrictions are triggered at 40% in autumn, and at 52% in early spring. So they vary depending on the time of year. 

How much more burdensome are the stage two restrictions? 

There’s not a lot of difference between stage one and two restrictions – just the watering of sports fields is stopped altogether. Most water is used indoors, which makes enforcement tough. You can’t restrict water use inside a building because you can’t see it. But when it comes to big businesses, we can use our contractual relationship with them to ask them to cut back. Under stage one restrictions, we’re asking them to save at least 10%. By stage two, this increases. It’s a big ask – but the situation will be serious enough to warrant that.

December 2018 and May 2020 (photo: supplied).

Why haven’t restrictions been imposed earlier? 

In February, when we started our Water is Precious campaign, the dam storage level was 70%, which was normal. We didn’t know then that the drought would continue through to winter. By the time we reached the trigger point whereby restrictions needed to be considered, Auckland was in the Covid-19 lockdown and compliance could not be monitored. So we let people know that restrictions were only a matter of time if they didn’t reduce their demand. 

No one likes anything enforced – it only works with a minority group. Most people do the right thing and comply if they understand the seriousness of the situation. Our challenge is to keep the drought top-of-mind during the cooler winter months. 

You’re asking Aucklanders to save 20 litres a day per person. This seems like a lot, but is it easier than we realise to save water? 

It’s easy to save 20 litres – spend two minutes less in the shower and you’ve hit your target.

About a quarter of the water used in a home is used in the shower, so it’s the best place to focus your water-savings effort. But there are other easy ways: if you turn off the tap when you brush your teeth, you’ll save four litres; if you use the half flush when possible, you’ll save six litres.

If a household washes one less load of laundry a week, they could save around 122 litres.  

Is this an opportunity for us to understand our water use better and become more efficient users of water? 

Absolutely, and that’s why we launched Water is PreciousAucklanders have been very good. Our domestic per capita demand is below 160 litres per person per day. 

But when it was very hot and dry in summer, that number shot up. People were watering their gardens a lot, showering a lot, and playing under sprinklers a lot. 

We need to value water. It is precious. And we can’t take it for granted just because we think it rains all the time in Auckland – look what’s happened. 

Keep going!