The device is fitted on to a property’s water meter overnight to identify hidden leaks on customers’ pipes.

It works like a stop-watch, showing the longest period of time it has taken for one litre of water to pass through a household’s water meter. The shorter the time, the bigger the leak.

Since the gadgets were put into operation in 2008, they have been fitted to 70,000 properties’ supply pipes across London and Thames Valley. 2,100 of those were found to have large enough leaks to warrant a repair or pipe replacement.

Thames Water modeller and LeakFrog co-creator, Leo Kiernan, said: “Up to a quarter of all leakage is from pipes belonging to customers.

“Leaks are not only a terrible waste of water but, if left undetected, can add hundreds of pounds to metered bills and cause damage to properties.

“So far the LeakgFrog has saved 10 million litres a day for our customers – that’s four Olympic-sized swimming pools every single day.”

Alison Brown

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