Bathing water rules in England should be improved to help drive a clean-up of pollution at a spot on the River Thames in Henley, campaigners say.

In a letter to the environment secretary, Emma Reynolds, businesses, river users, community groups and civic leaders said poor water quality had been damaging the town and had put public health at risk.

The letter said a stretch of the Thames through Henley – used for the annual rowing regatta – was turned down for bathing water status because of a narrow definition of those who use the river being confined only to “bathers”.

People who use the river for organised swimming events, rowing, kayaking, paddleboarding or sailing were excluded from being considered as river users by Defra when the town council submitted its application in 2024 because they are not classed as “bathers” under the legislation, the letter said.

Jo Robb, a member of the Henley Mermaids swimming group, said they were in a catch-22 situation, saying Henley cannot qualify for official bathing water status due to insufficient numbers of bathers, however, poor water quality discourages people from entering the river in the first place.

“The current system is fundamentally flawed and not fit for purpose,” said Robb. “We cannot improve water quality without bathing water designation, but we cannot achieve designation because water quality is too poor to attract bathers.”

Swimming events in Henley were cancelled last year due to falling entries amid concerns about water quality. Local businesses have said they are suffering.

Jonathan Hobbs, of boat hire service Hobbs of Henley, said: “My business, like many in Henley, depends on a clean river for its survival. It’s absurd that England’s premier river town cannot qualify for bathing water status under the current rules, leaving us with no way of cleaning up our stretch of river.”

The groups are calling for the government to implement several changes, including expanding the definition of “bathers”.

Water company sewage pollution is expected to be a major election issue in the forthcoming local elections in May. Labour has refused calls to renationalise the industry, and has so far not taken the decision to put struggling Thames Water into temporary public ownership under the special administration regime.

The Green party manifesto advocates for returning water companies to public ownership, describing the privatised system as a “failed experiment”.

Water quality in the River Thames at Henley repeatedly falls short of safe limits for swimming. Citizen-led water testing funded by the council and conducted by volunteers at Health on the Thames Water (HoT Water) has recorded consistently elevated levels of E coli.

Testing conducted in 2025 found E coli levels of up to 10 times the safe limit. E coli levels averaged 2,922 CFU (colony forming units) per 100ml over the three-month bathing season, which runs from 15 May to 30 September. The Environment Agency sets a limit of 900 CFU per 100ml as the limit for a bathing site to qualify as “sufficient”.

“Excellent” water quality requires E coli levels of less than 250 CFU per 100ml.

Dave Wallace, lead at HoT Water, said: “These levels pose a threat to anyone entering the water, but especially to children and those with existing health conditions. Our data is clear: the River Thames in Henley is a threat to public health.”

Bathing water designation would introduce regular testing of the river for fecal contamination and potentially force further treatment to improve water quality.

The government said it had noted the support for expanding the definition of a bather to include other recreational water users. They said work had begun on an evidence review to consider the environmental and public health implications of any change.

A spokesperson said: “The government is taking decisive action to clean up the nation’s rivers, lakes, and seas so communities across the country can enjoy the places they care about most.

“We are reforming regulations to better reflect how people actually use their local rivers, lakes and beaches, and are exploring expanding the definition of bathers to include participants in other water sports.”