Freeze-thaw resilience: the challenge for UK water network operators

Spare a thought for the engineers and technicians out in all weathers who’ll be dealing with a significant increase in leaks and bursts from UK water networks in the coming days. As research by WRc, UKWIR and others shows, a prolonged cold spell followed by a rapid thaw often leads to a significant outbreak of leaks and catastrophic pipe failures. It is a race against time for system operators as consumers expect a 24/7 supply.

Interested to hear from others outside the sector on this topic, I took my own poll of views from members of the general public. Influenced by the furore over storm overflow performance, the results of my (admittedly unscientific) poll suggested that network failure is largely attributed to operator mismanagement.

Contrast this with a root cause analysis of distribution pipe failures that WRc carried out for a UK client recently. This identified that only about a third of failures could have been operationally influenced by the water company – through, for example, better system pressure control.

Roughly another third of bursts was probably caused by weakened old iron pipelines being exposed to swings in environmental factors, including ground movement caused by seasonal changes in temperature and moisture levels. This happens every year, but our aging iron network is steadily becoming more brittle with time and less able to handle these seasonal weather shocks.

Ultimately, our brittle water network will all need to be replaced. At current rates of replacement, that is seven or eight generations away, way beyond the timeline for our limited understanding of population or climate change.

If the UK water sector is to reduce the consumer impact from leaks or bursts further, operators are faced with a tough balancing act: on the one hand, the need to maximise the benefits of pressure management, whilst at the same time persuading regulators that a significant proportion of water networks are still vulnerable to weather shocks, and that a faster rate of asset replacement is needed to sustain customer service in the longer term.

WRc provides independent and impartial expert assessment of leakage and pipe failure performance for operators across the UK, Europe and further afield. We focus on the evidence and blend our data science, hydraulic modelling and engineering capabilities to deliver insights. We also offer leak location and condition assessment services for larger pipelines: see our Asset Resilience Consultancy Services for more.