The UK’s bathing water forecasts need urgent improvement to prevent beach goers from swimming in sewage without warning, a new study has shown.

Stretches of river across England will be designated as swimming spots as part of Government plans to establish dozens of new bathing water sites.

A total of 27 new bathing sites would be designated under the plans, many of which are in rivers and lakes, significantly boosting the number of such official inland swimming areas.

One such location is Wallingford Beach, River Thames, Berkshire

With increasing attention on UK water companies and others to clean up rivers and beaches, the review, published in WIREs Water, suggests current bathing water forecast models are not keeping the public safe at most of the UK’s 600-plus designated bathing water locations.  

The current outdated methods cannot accurately predict threats from pollution caused by sudden downpours, the scientists say. Heavy rain can lead to sewage overflows or agricultural run-off.

In addition, a lack of water quality sampling and outdated forecast methods leave people vulnerable to sudden increases in chemicals or bacteria in the water.

With coastal and wild swimming becoming more popular, local authorities urgently need to make use of improved forecasting techniques to identify the dangers from bugs such as E. coli or intestinal enterococci, which can be lethal, the researchers said.

University of Reading Lead author Karolina Krupska said: "We expect beaches that are designated for swimming to be clean and safe, but authorities often don’t have good enough information to issue warnings, leaving swimmers and surfers more vulnerable to getting ill.

"The way we manage our sewage and land means rivers and seas are frequently polluted, and heavier summer downpours due to climate change is making the problem worse at the time of year when people are most likely to be at the beach.

“With existing pollution warning systems, beach users don't have good enough information to decide whether it is safe to go in the water.

"The science underpinning the next generation of bathing forecasting already exists, but a lack of action means these solutions have not been implemented.

“We need a more reliable and frequently updated early warning system, to ensure people can safely enjoy a coastal swim with the confidence that they aren’t putting themselves at risk.”

The proposed new bathing sites include the River Severn at Ironbridge and at Shrewsbury in Shropshire, Wallingford Beach on the River Thames in Berkshire, the River Wharfe at Wetherby, West Yorkshire, and the Cam at Sheep’s Green, Cambridge.

In addition, several spots on Coniston Water and one on Derwent Water, in Cumbria, would be added to the list under the plans.