A fibre-optic sensing technology is being piloted across part of Affinity Water’s distribution network to improve leak detection and enable faster intervention when faults occur in underground pipelines.
The system uses Distributed Acoustic Sensing (DAS), a technology that converts fibre-optic cables into thousands of virtual sensors capable of detecting vibrations generated by leaks in nearby water pipes. The pilot currently covers around 650 kilometres of Affinity Water’s network across five locations and uses telecommunications infrastructure from Openreach together with a fibre sensing platform developed by Lightsonic.
During the first three months of operation, the sensing platform identified more than 100 leaks, helping prevent the loss of around 2 million litres of water per day — equivalent to more than 700 million litres annually.
Distributed Acoustic Sensing (DAS) converts fibre-optic cables into thousands of virtual sensors capable of detecting vibrations generated by leaks in water pipes
The technology works by analysing tiny variations in the light signal travelling through fibre-optic cables. Vibrations in the surrounding environment, including those produced by escaping water, cause measurable disturbances in the light signal within the fibre. These changes can be detected along the cable’s entire length, allowing operators to identify the approximate location of a leak.
Machine learning plays a central role in processing the acoustic data generated by the system. Algorithms are trained to distinguish the acoustic signature of leaks from other sources of vibration, such as road traffic, construction works or other urban noise. When a potential leak is detected, the platform can highlight an area for investigation, often narrowing the location to within a few metres.
Unlike traditional leak detection methods, which typically rely on periodic field surveys and specialist teams moving through the network, fibre-optic sensing provides continuous monitoring. This allows leaks to be identified earlier and can reduce the time between detection and repair.
Because the approach uses fibre already installed underground, it avoids the need to deploy additional sensors or undertake extensive excavation. This also makes the system easier to scale across larger areas where fibre-optic infrastructure is available.
James Curtis, Head of Leakage at Affinity Water, said: “Strengthening how we identify and address leaks is central to our leakage strategy. By working with Lightsonic and Openreach, we’re enhancing our existing detection programme with continuous network monitoring, helping our teams target areas of interest more quickly and reduce the time leaks may run before repair.”
