Who will pay for the Thames Tideway Tunnel?

Construction of the Thames Tideway Tunnel is expected to cost £3.8bn to complete, with an additional £1.1bn for preparatory works. This will be privately financed, with no public money expected to be spent on building this extra capacity for London’s Victorian sewer system.

Reading Sewage Treatment Works

Reading Sewage Treatment Works

Over time, the tunnel will be paid for by all the customers who use Thames Water’s sewerage service – but just like taking out a mortgage on a property, it doesn’t have to be paid all at once. Tomorrow’s customers will also help to pay, because they’ll benefit from the tunnel too.

Around £19 of the average annual household bill for 2019/20 funds this project, and this amount will gradually rise to £20 - 25 a year, before inflation. We will continue to work as efficiently as we can, keeping our customers’ wastewater bills as low as possible.

Spreading the costs of a big investment project like the Thames Tideway Tunnel is widely seen as a fair approach, and it’s standard practice in the water industry across England and Wales.

For example, people in the Lake District have contributed to a major clean-up of the Mersey in Liverpool, and customers in Milton Keynes have helped to protect beaches in Norfolk.

In the Thames Water region, residents in the London area have already helped to pay for projects as far afield as Cheltenham, Sevenoaks and Bishops Stortford. Londoners’ bills have also contributed to big infrastructure projects like Reading’s state-of-the-art sewage works, and improvements to the treatment works at Crawley and Merstham in Surrey.

In each of these cases, most customers won’t have noticed much immediate benefit for themselves and their families. But when improvements have been needed closer to home, people have benefited personally from the costs being shared across all their local water company’s customers.

In the end, when work needs to be done to protect our environment and make the UK a better place to live, everybody contributes a little, and everybody benefits.