Thames Water has launched a probe into the impact of data centres on water supplies in and around London as the company is set to impose a hosepipe ban on its 15mn customers in one of the worst drought-hit areas of the UK this week.

The company, which has faced heavy criticism over its dismal record on fixing leaks, has started what it called a “targeted exercise” to understand how much drinking water the 24-hour facilities — which generate huge amounts of heat — use to cool their servers, given the scale and demand of the sites around the capital.

John Hernon, strategic development manager at Thames Water, said he had launched the review because of the growing demand for data centres particularly in the Slough area, which is set to become the second biggest data centre hub in the world.