Christchurch to be asked to reduce water use while billions of litres still lost through leaky pipes

Friday, 13 November 2020

The number of pipe leaks fixed each month in Christchurch almost doubled in the year to February 2019. (Video first published in 2019)

The amount of water lost in Christchurch through broken pipes, leaks and supply network faults has soared by a third in the last two years – yet residents will soon be asked to curb their use.

Initial estimates suggest 11.64 billion litres were lost last year, the equivalent of 31.9 million litres every day, or 90 Olympic-size swimming pools a week.

That is almost three billion litres more than the 8.68b litres wasted in 2017-18, though the percentage lost in 2019-20 was down on the previous year.

Despite hundreds of millions of dollars being pumped into revamping ageing water infrastructure, there are warnings the city council will be unlikely to get on top of the problem any time soon.

* Leaky pipes lose 70 swimming pools worth of Christchurch water a week

Water leaking out of meter boxes in Hamilton Ave, Ilam.

* Strictest water restrictions since earthquakes on way in bid to bring well repairs back on track

More than 420 kilometres of pipes are in such poor condition they are expected to fail in the next year.

Council-owned maintenance company Citycare has a backlog of 881 service requests, 696 for unplanned issues such as burst pipes.

Extra staff are expected to be drafted in over summer to ensure leaks are repaired, as they were last year.

A Christchurch City Council truck gets stuck among a burst water main on Worcester St.

Reports of problems are almost 50 per cent higher than before chlorine was introduced to supplies in 2018.

A staff memo to councillors in September 2020, acquired by Stuff, said the volume of requests more than doubled from about 1000 per month to more than 2000 by March 2019.

“This trend has continued unabated in 2020, albeit at a reduced level to the 2019 peak.”

Residents reported about 1565 problems in October, and contractors carried out 11,029 repairs in the first eight months of 2020, averaging 1379 a month.

“We are currently receiving, on average, 50 water service requests relating to water per day, and most of these are for leaks,” head of three waters and waste Helen Beaumont said.

Christchurch Girls’ High School closed for a morning in October 2016 after four water mains burst on Kilmarnock Rd.

“All urgent jobs are completed quickly and significant leaks are prioritised over other works.”

The rise in service requests was partly due to much of the water network reaching the end of its life.

Councillors were told it was also likely to be down to pressure fluctuations from starting and stopping pump stations more frequently since chlorination began.

Prolonged dry weather exacerbated pressure on the network and meant minor leaks became more obvious, the memo said, while water conservation campaigns and a council app to make it easier to report leaks may have encouraged service requests.

A water main bursts on Colombo St just north of the roundabout with Centaurus Rd.

Public demand for water is at a five-year-high, and the subsequent strain on the network means leaks could get worse.

Each Christchurch resident used on average 375 litres of water a day in September, far above the council’s target of 298 litres, and the figure is expected to rise further in the coming months.

Annual rainfall at Christchurch’s Botanic Gardens is the lowest for 10 years, and with Niwa predicting above average temperatures this summer and for low rainfall to continue, the council will later this month launch a campaign asking residents to be mindful of excessive use.

“The key concern is we might have to impose city-wide water restrictions earlier and for longer unless residents change the way they use water outdoors,” Beaumont said.

“If enough people water wisely, we might be able to get through the summer without the need for water restrictions, or at least avoid heavy restrictions.”

Councillor Yani Johanson said it was unfair to impose on residents when the council was yet to get its own house in order.

“I don’t see how we can expect people to save and conserve water when they’re reporting leaks and they’re not getting them fixed on time.”

In the 2019-20 financial year, Christchurch city used about 56.7 billion litres of water, for everything from drinking water to firefighting.

About 11.64 billion litres of water was lost through leaky pipes and infrastructure in Christchurch last year.

Of that, 20.5 per cent was lost – or about 11.64 billion litres.

That was down on the 22.6 per cent, or 11.16 billion litres, wasted from the previous year’s 49.47 billion litres of use, but up on the 8.68 billion litres lost in 2017-18, or 17.9 per cent of the 48.48 billion litres taken for use.

But while the council’s target is 15 per cent, councillors last week were told that goal is “not likely to be achieved in the medium term”.

Leaks in the city’s 3600km of water supply pipes are not the only problem, with faulty meters and overflows from storage tanks also responsible.

Following the earthquakes, the Stronger Christchurch Infrastructure Rebuild Team spent about $2.2 billion on below-ground infrastructure.

But repairs were limited to quake-damaged pipes that were expected to fail within five years, and mainly on the wastewater network.

Current problems relate to large portions of the network coming to the end of their lives, as well as outstanding quake damage.

Renewing older and poor condition water mains was the most effective way of cutting leakage, Beaumont said.

“The rate of renewal work has been much less than ideal since the earthquakes due to other calls on council’s finances.

“Increasing the rate of renewals would improve the leakage however the programme of renewals would be delivered over a number of years.”

Earlier this year the council scrapped a proposed excess water charge that could have raised $2m. That plan, and a further renewals programme, will be considered under next year’s long-term plan.