How we're wasting 100 billion litres of water every year

Thursday, 11 January 2018

A leaking water main in Hebden Cres, Lower Hutt, last month angered residents and businesses, who were subject to water restrictions.

Water is one of New Zealand's most precious commodities, yet we're losing more than 101 billion litres of it every year through leaks and wastage.

The losses equate to almost 18 per cent of the total national supply of 572b litres, and are blamed on ageing and eroding supply systems, household leaks, pipes damaged by underground works, earthquakes and landslides, and metering errors.

The statistics were gathered by Water New Zealand for its 2015-16 national performance review, which compiled data from 50 participating councils, accounting for 90 per cent of the population. A review of 2016-17 is due out next month.

Though New Zealand is water-rich, experts think the resource is under more pressure than ever before.

Water NZ technical manager Noel Roberts said New Zealand was water-rich, but pressure on the resource had risen in recent years because of increased industrial and commercial use.

**READ MORE:

Residential water consumption among the 50 councils that took part in Water NZ's 2015-16 survey. Kaikōura's consumption appears unusually high because it includes non-residential users, including several farms on town supply. Masterton, which also has high usage, does not appear on the graph because it did not take part in the voluntary survey.

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Water pipes are often damaged by workers, by earthquakes or landslides.

Old, decaying council infrastructure was a major concern, as was damage done by work crews, and undetected leaks in people's homes. But huge costs often prevented local authorities from repairing or replacing pipes.

'Some areas have pipes that are up to 150 years old. In [Wellington suburb] Thorndon, there are pipes that are 135 years old still being used. Often the pipes are checked and, even if they are older than recommended, they are kept if working.

Water NZ's Noel Roberts says smaller councils often do not have the resources to deal with water infrastructure issues. (File photo)

'It is a considerable expense to dig them up and replace them. A lot of smaller councils do not have the resources to really look at water supply issues properly.'

One of the worst offenders in terms of water wastage is Masterton, in Wairarapa.

Masterton District Council chief executive Pim Borren acknowledges its high water use, but says smaller town tend to use more than built-up urban areas, because of bigger sections and fewer apartments.

It loses about 5.6 million litres a day to council and residential leaks, according to Masterton District Council's water management plan. That equates to more than 2b litres a year.

However, the council did not take part in Water NZ's voluntary survey, and Water NZ believes the actual figure could be higher.

Masterton's usage and leakage equates to 655 litres a person a day – more than twice the national average of 259 litres.

It had been as bad as 900 litres a person a day in 2015, before significant work was done.

Council chief executive Pim Borren said Masterton was continuing to make progress in reducing water usage, and was aware that usage and leakage were still too high.

Leaky taps in homes, and damage to pipes during renovations caused a lot of waste, he said, as did damage from work crews.

'When the broadband system was being put in over the past few years, there were numerous instances of damage being done to pipes …

'These leaks are often not picked up for some time, meaning water wastage can go undetected for long periods.

'Because it's all buried and hidden it is much harder to pick up.

'Most of our pipes are around 100 years old. We need to upgrade all of our pipes to PVC and will continue to do so, but it is an expensive process.'

He said smaller towns tended to use more water than built-up urban areas, because of bigger sections and fewer apartments.

'We are not denying we are high users, though the leaks are in both the council system and on residential properties. Installing residential water meters is something we are looking at which will help, and we need to continue fixing council pipes.'

Federated Farmers' spokesman for water issues, Chris Allen, said the waste in urban areas was concerning but not surprising, given the lack of investment nationwide in water infrastructure.

The farming sector would like to see more effort being made across the country by everyone to ensure care around water delivery and use.

'Farmers, especially those with irrigation systems, are already using water as efficiently as technology allows. We are always on the lookout for sensible, practical and affordable solutions to managing freshwater better.'