Acoustic fibre sensing aids UK water leak detection

Southern Water has partnered with Lightsonic to deploy acoustic sensing on existing fibre-optic cables to locate water leaks. The technology has already saved over 4 million litres per day across 650km of network. It works by detecting vibrations from leaking pipes that affect optical signals in nearby fibre cables.

The UK loses an estimated 2.6 billion litres of water daily through leaks in its ageing pipe infrastructure, yet pinpointing exact failure points has historically required costly manual surveys. Lightsonic's approach repurposes Openreach's existing full-fibre cables as distributed acoustic sensors, detecting the subtle vibrations that escaping water creates in nearby soil and pipework. The company reports that its system typically identifies roughly 1.2 million litres of leakage per day for every 100km of network monitored annually.

Southern Water's deployment spans 650km of network and has already yielded savings exceeding 4 million litres daily. Openreach previously trialled the technology with Affinity Water in March, and the partnership's expansion suggests growing confidence in passive sensing as a scalable monitoring solution. The timing coincides with record summer temperatures, hosepipe restrictions, and a five-year delay to a planned reservoir project, intensifying pressure on utilities to find rapid, cost-effective conservation measures.