THAMES Water has applied to industry regulator Ofwat to increase water bills next year by a one-off £29.

However, to avoid a spike in its customers’ bills, the company has recommended spreading the payment over a number of years.

The increase is to pay for the land needed to build the Thames Tideway Tunnel, which cost £273 million.

Despite the scheme only benefiting people living in the London and the Thames Valley, customers in Swindon will have to pay the cost as Thames Water say it is fair to spread it across all its customers.

The water supplier, which has nearly 14 million customers, is in the middle of a price control period agreed with Ofwat but they are allowed to request an increase if an unforeseen cost occurs after the agreement started in 2010.

Stuart Siddell, chief financial officer, said: “These costs could not be quantified at the beginning of the current pricing period, and their scale is unique to Thames.

“Increasing prices is never good news, which is why the company is encouraging Ofwat to allow the price increase to be spread over more than one year.”