Is this the end for listening sticks? It could be at Southern Water.
The company – responsible for four million customers – is celebrating a record year of finding and fixing leaks.
And it’s all thanks to their new system of 24,000 acoustic loggers.
The rod may have been a trusty tool for many years, but these sensors – spread out across Southern’s 15.5km network – can alert the control centre to a tell-tale hiss or gurgle in an instant.
One of their 90 teams of ‘leak busters’ is then dispatched to deal with the problem.
Southern managed to cut weekly leakage over 15% between April 2024 and April 2025 – from 108.1m litres of water lost per day to 91.1m litres.
The savings represent enough water to serve 35,000 customers.
Overall, during those 12 months, the system saved a total of 138.7 million litres per day, which would otherwise have been lost through leaks. This compares to 107.7 million the previous year – a 28.8% boost.
A spokesman says this represents the biggest cut in the company’s history, and around a fifth of the average amount of water put into supply at 566 million litres per day.
Tim McMahon, Managing Director of Southern Water, said: “There’s been incredible work by our teams around the region – finding and fixing the leaks from big pipes far below the ground which show no trace on the street.
“Thanks to clever technology and new control systems, we are able to prevent pressure spikes which can burst water mains and work as fast as possible to respond to every reported leak.”
The company currently has around 160 employees undertaking leak detection activities, either repairing leaks on the ground, or working in the control room on planning, reporting and performance improvement.
In total, teams repaired 20,820 leaks on the network last year, as well as 3,488 repairs to customer pipes.
But preventing leaks in the first place is another challenge.
Tim explained: “We have our biggest ever water mains replacement programme underway with 50km of older PVC pipes being replaced by the latest technology during 2025 alone.
“But with more than 15,000km of network mains, replacement has to be carefully targeted. Managing pressure in pipes to prevent spikes can stop the older mains from splitting and prevent leaks – and stop customers from losing pressure.
“I’m giving my team a big pat on the back – but there’s no victory lap or tea in the pavilion, just lots more work to do.”
And not content to rest on their laurels, Southern continues to explore other innovative technologies in the fight to conserve water.
