The Environment Agency said that water company efforts to protect the environment are few.
Only one of the nine major companies, Northumbrian Water, is performing at the expected level, with most likely to miss 2020 targets, the agency added.
“There’s no getting away from the fact that performance in 2018 was simply unacceptable”, said Environment Agency chairwoman, Emma Howard Boyd.
Agency director of operations Dr Toby Willison added: «Water companies need to clean up their act».
How to improve the environment? «Six out of nine companies are rated good or better in the assessment, and the most serious pollution incidents are down 18% on the previous year, but there is much more to do across the board to achieve the high standards which people rightly expect water companies to meet».
Environment Secretary Michael Gove said the “damning report” showed all but one firm was «failing to protect» waterways from «serious pollution and the effects of climate change».