Water companies have been warned over serious pollution incidents, as the Environment Agency called for penalties to be made tougher.
Fines should be made proportionate to the turnover of the company and the courts should apply penalties consistently for them to be an effective deterrent, the agency said.
About 60 serious pollution incidents a year are caused by water companies, a report published on Monday said. The number of serious incidents caused by water companies has remained the same for the past decade, although incidents have declined by 70% since 1995.
Water companies must work to reduce the number of incidents further, the report said, as it predicted that an increase in housing, industrial growth and urban creep will put pressure on sewerage infrastructure and cause the system to flood more frequently.
Urban creep is the increase of the impermeable area due to the installation or enlargement of patios, extensions and driveways, and it is thought to have a similar impact to population growth and climate change.
Environment Agency chairwoman Emma Howard Boyd said: “Water quality is better than at any time since the Industrial Revolution thanks to tougher regulation and years of hard work by the Environment Agency and others.
“But there are still far too many serious pollution incidents which damage the local environment, threaten wildlife and, in the worst cases, put the public at risk.
“I would like to see fines made proportionate to the turnover of the company and for the courts to apply these penalties consistently. Anything less is no deterrent.”
Thames Water was fined an “unprecedented” £20M in March last year for a series of pollution incidents after untreated or poorly treated raw sewage was discharged into the River Thames at sites in Oxfordshire, Buckinghamshire and Berkshire between 2012 and 2014. Yorkshire Water was hit with a £600,000 penalty in 2016 after an ageing sewage pipe burst, killing hundreds of fish.