9% of Sydney’s water goes down the drain

The average resident is using 26 litres less water a day than a year ago but worsening leaks caused 9% of the 570,643 megalitres supplied by Sydney Water in 2018/19 to go down the drain.

As the drought causes clay soil to contract, Sydney Water’s 47,000 kilometres of water and wastewater pipes were cracking under pressure, causing leaks and breaks.

“These factors led to a higher backlog of repair jobs and increase in the time leaks are running before repair,” a report has found.

It comes as the NSW Minister for Water Melinda Pavey said average daily water use per person was down 7% from 209 litres in 2017/18 to 193 litres in 2018/2019. It has dropped another 10 litres since then.

About 568 megalitres of water was used across residential and business in 2018/2019, down from 600 megalitres in 2017-18. About 65% of water is used in homes.

Sydney Water’s executive drought lead, Catherine Port, said demand had fallen more in November showing the impact of its investment in water efficiency. Its public awareness campaign had lifted attention to the drought to more than 75% of the population.

But the leaks have got bigger, the Water Conservation Report has found, although it noted that a leakage rate of 9% was still among the best in the world with many other water utilities losing more. The report was provided to the Independent Pricing and Regulatory Tribunal which is setting water prices for 2020.

“This causes an increase in leaks and breaks … The drought also causes tree roots to seek out moisture anywhere … including our network – leading to an increase in sewer chokes,” the report found.

Often mains requiring repairs were under major roads and required liaising with councils and traffic authorities.

The report found leaks each day rose from 114 megalitres in 2016-2017, to 129 megalitres in 2017/2018 and 131 megalitres in the latest findings.

“One leaking tap can waste around 2000 litres a month,” Ms Port said. In addition, about 571 megalitres was lost last year to water stolen from the system known as “unauthorised consumption”.

Sydney Water has invested $30 million (S$27.9 million) in increasing frontline crews and has also inspected 15,000 km of pipes in 2018/19 compared with 9000 last financial year.

Plumbers told the Herald they were “definitely” seeing more water leaks, as the clay soil contracted, as well as more cracks in terracotta sewage pipes. Steve Jenson, operations manager of Pav Plumbing in St Peters, said he was seeing a lot of tree roots wrapped around sewer pipes, and then blocking the pipes.

Consumers are responding to the drought by taking advantage of a Sydney Water programme which provides a free service to fix leaking taps. More than 5000 residents had booked appointments, which were forecast to save 110 million litres a year.

The Waterfix Strata programme was also reducing water use and leaks in apartments. Windsor Plaza Strata saved its body corporate $44,000 (S$40,987.14) a year. It had a high number of renters, many of whom were unwilling to raise problems with their property managers.