Water companies in England and Wales have been telling the regulator Ofwat how much they want to increase bills for the five years from 2010. Thames Water is expecting one of the highest rises of about 3% a year above inflation. United Utilities plans to raise prices by 2.7% above inflation. Northumbrian’s figure will be 1.3% and Anglian Water sees a 0.7% rise. Severn Trent asked for rises “only slightly above inflation” while Welsh Water’s will not rise above inflation. Overall the firms aim to invest £27bn during the period to ensure the “right balance between supply and demand”, said Water UK, which represents UK water and wastewater service providers. The average bill in 2015 is expected to be £350, with bills increasing £30 over the five-year period, it said.   We have to make sure that our infrastructure, our networks, our treatment works are all ready to cope with an influx of people . “The combined industry programme is a major and timely investment in national infrastructure that everyone depends on and we know will be severely challenged by climate change,” said Pamela Taylor, Water UK’s chief executive.  Thames Water, the UK’s biggest water company, said its £6.5bn investment plan would be the largest spending programme carried out by a UK water company. The firm said its customers had “enjoyed the lowest bills in the industry for many years”, and while there would be “an inevitable impact on bills”, it would try to keep charges below the industry average. Peter Antolik, Thames Water’s director of regulation, told BBC Radio 4’s Today programme that the money was vital to improve London’s ageing water system. “We also have, it should be remembered, a growing population in London and the south east,” he said. “We have, we estimate, about 380,000 more people coming in to the region and we have to make sure that our infrastructure, our networks, our treatment works are all ready to cope with that influx of people.”

Welsh Water announced plans to invest £1.5bn, or £1,000 per household, on average during the period. The money will be used to protect the quality of the water, support new infrastructure, improve water treatments and reduce the risk of repeat sewer flooding to properties. The firm’s average household bill will be £390 before inflation.

United Utilities said its capital investment for the period would be £4bn, of which £1.6bn would be for water services and £2.4bn would be for water waste services. While the firm said it would increase prices by 2.7%, bills were tipped to rise by 2.1% on average thanks to greater use of water meters.

However it added that it would reassess its costs when it submits its final plan to Ofwat in 2009 “in light of financial market conditions at that time”.

Severn Trent said it would invest £3.2bn to deliver improved services, reinforce the network following last summer’s flooding and reduce sewer flooding. It also said the money would be used for environmental improvements. Tony Ballance, the firm’s director of regulation and competition, said: “We believe our draft plan provides the best balance between improved services, the needs of the water environment and a cost that customers are willing to pay”. Anglian Water said it would increase the average household bill from £360 in 2010 to £373 in 2015, an annual rise of 0.7%.