Household water and sewerage bills will go up by an average of 7% in England and Wales in the coming financial year, regulator Ofwat has confirmed.
South West Water has spent £1.5bn on cleaner beaches
It says this will push up the average household bill by £20 to £312.
Ofwat said the size of the bills would vary between water companies, with the biggest increase, £44, being for customers of South West Water.
Ofwat first set the price increases for 2005-10 in December 2004, with the next industry price review due in 2009.
"We recognise that any bill increases are going to be unwelcome," said Ofwat's chief executive Regina Finn.
"But these increases are essential to ensure that customers continue to receive high quality, secure water and sewerage services, both now and in the future. The increases are also partly driven by significant environmental improvements," she added.
There was a less than enthusiastic welcome from the Consumer Council for Water.
Dame Yve Buckland, chair of the consumer body, said: "Many consumers on low and fixed incomes will struggle to keep up with these bill rises.
"Consumers will also struggle to understand the relationship between higher bills, increases in company profits, last summer's water restrictions and acknowledged recent failures in customer service."
Ofwat's confirmation of higher prices also affects the smaller water-only companies.
One of them, Tendring Hundred, will cut its charges by £5 in 2007-08.
It is doing that to repay customers who were overcharged in 2005-06 and 2006-07 because of accounting errors at the company.