The average household water and sewerage bill in England and Wales is set to increase by 3.5% over the next year, regulator Ofwat has said.
Households will pay an average of £388 from April 2013 to March 2014 - 0.5% above the rate of inflation.
Ofwat chief executive Regina Finn said: "Back in 2009, companies wanted bills rises of 10% above inflation. That didn't chime with what customers told us they wanted, so we said they could only increase bills in line with inflation.
"We understand that there is huge pressure on household incomes, and any rise is unwelcome. Inflation is driving these increases."
"We will make sure customers get value for money and if companies fall short in delivering their investment promises, we will take action," Ms Finn added.
"In the past seven years, we have made companies pay out around £550 million where they have underperformed."
The new charges will vary for households depending on their supplier and whether they have a water meter, Ofwat said.
The increased bills will help pay for an investment programme worth about £25 billion between 2010 and 2015, the regulator added.