Water companies have been urged to invest their profits in cutting bills to “rebuild” trust in the tarnished industry, as suppliers in England and Wales announced costs would jump from April. Water UK, the industry trade body, said bills would increase by 6% or £2 a month on average next financial year – far more than the current 4% inflation rate. But the industry said bills would have been £60 higher if they had kept pace with inflation over the past decade. However, the group’s argument will do little to reduce public outrage during a cost of living crisis for an industry that has been condemned for sewage dumping, years of underinvestment in infrastructure, large dividends, big bonuses and high debt levels. Water UK said the average combined bill for water and sewage services would be £473 – or £1.29 a day – from April. However, each supplier has set its own rates, based on factors including allowances and restrictions by the regulator Ofwat, bill increases in previous years and inflation. Wessex Water customers face the most expensive bills, with their annual cost rising to £548 next financial year, from £489. Anglian customers will pay £529, up from £489. The Observer revealed last month that the north Wales water company Hafren Dyfrdwy was expected to make the biggest increase, while Welsh Water was likely to reduce bills as a result of penalties for supply interruptions and leakage during the last financial year. Annual bills for Hafren Dyfrdwy customers will jump nearly 20% to £433. Welsh Water will cut bills by £20 to £492 and South West Water will shave £2 off annual bills by next year. In September, Ofwat ordered 12 underperforming companies to take £114m off bills from April, including £101m from debt-laden Thames Water. Severn Trent was allowed to add £88m. Last year the industry vowed to invest £10bn to tackle sewage pollution, but “urgent” plans to detail the investments for MPs have been delayed. On Friday, Water UK said companies would invest £14.4bn – the highest amount in a single year – to help “ensure the security of our water supply in the future and significantly reduce the amount of sewage in rivers and seas”. The Water UK chief executive, David Henderson, said: “Next year will see record levels of investment from water companies to secure the security of our water supply in the future and significantly reduce the amount of sewage in rivers and seas.” These investments include the completion of the Thames “super sewer”; work on the Havant Thicket reservoir project in Hampshire; and a £39m water treatment works to be built by South East Water in Kent, where residents have endured supply interruptions and water shortages. Henderson said support for customer bills was doubling, with more than 2 million families to be helped. But the Consumer Council for Water (CCW) repeated calls for the remaining water suppliers to join Welsh Water, Severn Trent, Yorkshire Water, SES Water and United Utilities in using their profits to help fund social tariffs, rather than part-funding this through charges on other customers. Mike Keil, the chief executive of the CCW, said: “Almost a fifth of households say they struggle to pay their water bill, and these rises will heap even greater pressure on low-income customers. If water companies are serious about rebuilding trust in the sector, they should use some of their profits to help people who cannot afford another bill rise.” The Liberal Democrat environment spokesperson, Tim Farron MP, said: “This is a kick in the teeth from the same dodgy water firms who pollute rivers with sewage while pocketing millions in bonuses. They have no shame. This price hike is a disgrace and should be scrapped immediately.”