Exclusive: leakage rose in 2012-13

Leakage measured as a percentage of overall water delivered rose last year, according to a Utility Week analysis of water company data submitted to Ofwat.

Of the ten water and sewerage companies, all but two recorded a rise in leakage as a percentage of water delivered.

Ofwat questioned the use of this metric, claiming it was skewed by the overall percentage of water delivered having dropped in 2012-13. But independent expert David Lloyd Owen, managing director of water management consultancy Envisager, said it “gives you a pretty crisp picture of what is going on”.

“Percentage leakage is very simple, it is what goes in and what goes out not being used,” he added.

Welsh Water and South West Water had the highest change in leakage as a percentage of water delivered, rising 5.05% and 4.81% respectively from 2011-12 to 2012-13. Severn Trent and Yorkshire Water were the only companies to reduce leakage as a percentage of water delivered.

South West Water argued that leakage measured as a percentage of water delivered does not take into account factors such as network size or operating pressure, of which the water company has the highest in the UK due to the topography of the region.

Andy Blackhall, Water Demand Manager at Welsh Water, said: “We find and fix on average more than 100 bursts and leaks every day, and last year, we again achieved our leakage target. Since the 1990s, we have halved leakage on our water supply system.”

South West Water (3.63%), Thames Water (1.32%) and United Utilities (0.96%), recorded the greatest percentage increases in total leakage.

Jacob Tompkins, managing director of Waterwise, said: “It is highly concerning that leakage is rising.”

The analysis from Utility Week is based on updated cost and performance data submitted to Ofwat in August by water companies in preparation for the 2014 price review.

• See this week’s issue of Utility Week, out on Friday, for more analysis of the latest leakage figures