Household water bills are to fall by around £20 over the next five years in England and Wales.

The 5% drop, excluding inflation, would see average bills come down from £396 to £376 by the end of the decade, according to the industry regulator Ofwat.

The price ruling by Ofwat confirms a provisional determination in August.

When the process for setting bills began last year, water companies had submitted plans which would on average have cut bills by 2% in real terms.

Ofwat rejected a request by the UK's biggest water company, Thames Water, to increase household charges by 3% over the period 2015-20 to help pay for the £4.2 billion super-sewer project.

The firm has been told it must instead cut them by 5%.

It also said utility firms must improve efforts to tackle water leakage, supply interruptions, sewerage water flooding of properties and see cleaner water at beaches.

Ofwat chief executive Cathryn Ross said: "With bills held down by 5% and service driven up over the next five years, customers will get more and pay less.

"Where companies stepped up to do the best they could for their customers we did not need to intervene, but where companies fell short we stepped in to make sure customers get a good deal.

"Now the hard work begins. Companies will only build trust and confidence with their customers if they deliver.

"Those who do can look forward to fair returns, while those that don't will be hit in the pocket and face a tough five years ahead."