Detecting Leaks Without New Infrastructure: Lessons from Portsmouth Water

Non-revenue water remains one of the most persistent challenges in the water sector, and the standard fix, dividing a network into district meter areas (DMAs), isn’t always the right one. Bob Taylor, Chief Executive of Portsmouth Water, joined the Exec Exchange podcast to explain why his company took a different path, and what it learned along the way.

A Resilient System, Built Differently

Portsmouth Water draws most of its supply from a chalk aquifer, distributed across roughly 20 sites plus a small surface water source. That distribution, combined with above-average reservoir storage and constant-rate pumping, gives the network natural resilience that isn’t dependent on any single treatment works.

Why Only Half the Network Is Sectorized

Unlike most UK water companies, Portsmouth Water has held back from fully sectorizing its network into DMAs. Taylor’s predecessors judged that breaking the network into isolated zones would reduce resilience and create water quality risks. The tradeoff is a harder leakage detection problem on the unsectorized half of the network, since there’s no meter at the boundary of each zone to flag anomalies.

Testing a Dutch Alternative

Taylor identified a Netherlands-based company, HULO, whose data analytics platform was built for exactly this kind of open, unsectorized network, the norm in the Netherlands. HULO uses existing pressure and flow monitoring data to build a model of a network’s steady-state behavior, then flags deviations from that baseline in real time.

Putting the Model to the Test

Portsmouth Water ran trials across six network areas without installing any additional sensors. To validate the model, staff opened hydrants at undisclosed locations and challenged HULO to detect the resulting anomaly. The model succeeded in five of six tests, working entirely from data collected off-site in the Netherlands.

Weighing the Investment Case

For Taylor, the appeal is straightforward: avoiding the capital cost and multi-year rollout time of new district metering while still gaining the ability to detect and respond to leaks quickly. Portsmouth Water is now deciding how much additional monitoring, if any, would be needed to expand the approach further.

As utilities across the sector face growing pressure to cut leakage and manage capital budgets carefully, Portsmouth Water’s trial offers a useful reference point: sometimes the answer isn’t more infrastructure, but better use of the data already being collected.