Summer warning on the dangers of swimming in open water during hot weather

29 July 2026

Parkswim at Daventry Country Park was suspended at the start of July due to the presence of cyanobacteria, or ‘blue-green algae

As temperatures remain high across West Northamptonshire, local partners are urging residents and visitors to think twice before entering lakes, rivers, reservoirs, pits, canals and other areas of open water.

West Northamptonshire Council and the Environment Agency have warned that while these watercourses might appear safe, they can contain hidden hazards.

According to guidance produced by the UK Health Security Agency and the Environment Agency, swimming in rivers, lakes and other open water locations can increase the risk of gastrointestinal illness, including diarrhoea and vomiting, as well as ear, eye, skin and respiratory infections.

In some circumstances, exposure to contaminated water can result in more serious conditions such as E. coli infection or leptospirosis, also known as Weil's disease, which can affect the liver and kidneys.

Cllr Laura Couse, West Northamptonshire Council Cabinet Member for Adult Care and Public Health, said: "We understand that people are looking for ways to cool down during periods of hot weather, but entering open water can carry serious risks that are often underestimated.

"As well as the immediate dangers associated with drowning, there are important public health considerations.

“Even when water appears clear, it may contain bacteria and other contaminants that can cause significant illness.

“We are asking everyone to enjoy the summer safely, follow local safety advice, and choose supervised swimming facilities wherever possible."

Environment Agency Area Flood and Coastal Risk Manager, Ben Thornely, said : "We want people to be able to safely enjoy our natural waterways.

 "Our rivers and lakes are home to a wide range of animals and birds and naturally contain different bacteria, some of which can make people unwell.

“Members of the public are encouraged to follow water safety advice and to always check Swimfo for latest advice of swimming at designated bathing sites.”

Further information on cold water shock and floating advice is available from the RNLI.

Health advice on open water swimming is available from the UK Health Security Agency and the Environment Agency.

For information on where to swim safely, visit the Swimfo site.