Authorities say good weather has helped reduce the rate of main water pipe breakage in South Australia. 

In 2021, South Australia recorded the lowest number of water main incidents for the past four years, with 3,614 water main leaks and breaks reported in 2021 across SA Water’s 27,000-kilometre network, compared to 3,749 in 2020. 

These figures include everything from major breaks to minor pipe leaks, damp patches and trickles on the road.

The authorities say that in SA, particularly Adelaide, reactive clay soils move during the transition from hot and dry seasons to wet and cool. The stress this causes on underground pressurised water pipes is the number one cause of water main incidents.

However, the most recent transition was relatively mild, “resulting in more stable levels of moisture in the soils and therefore fewer water main breaks”, according to SA Water General Manager of Sustainable Infrastructure Amanda Lewry. 

“This is compared to 2018 and 2019 when the state experienced searing hot temperatures and below average rainfall, so when it did rain, the abruptness of the event had an increased impact on water mains, with break rate figures in these years closer to 4,000,” Ms Lewry says.

“The less challenging conditions in 2021 coupled with our sustained focus on driving customer outcomes by reducing the impact of water main breaks, were what led to an improved water main incident rate.

“Last year, we installed around 59 kilometres of new water mains across South Australia – including under several key arterial roads in Adelaide.

“Across 2020-24, we’re investing $155 million to improve water services for our customers and maintain South Australia’s water infrastructure, including by expanding our use of smart technology.”

The 2020-21 results show South Australians experienced 13.3 water main breaks or leaks per 100 kilometres of pipe, which is lower than the average of 18.9 and better than more than half of comparable-sized Australian water utilities (with 100,000 or more customers).