The water company has urged people not to swim in reservoirs, lakes and rivers, with the warning issued as young people prepare to celebrate A-level results.

United Utilities is sharing videos featuring members of the emergency services which warn about the risks of entering open water and explain what people should do if they get into difficulty.

Jo Harrison, Asset Management Director at United Utilities, said: “Sadly, every year when we get a spell of warm weather, there are drownings in waterways across the country. It is heartbreaking to see this loss of life, particularly when many of the victims are so young.

“Our reservoirs may look like a tempting place to take a dip, but they have hidden dangers, such as cold temperatures, hidden operational equipment, and steep sides which can make it difficult to get out. They are also often in remote locations which makes rescue difficult when people get into trouble. Our message to young people is clear: please don’t take the risk.”

Grant Baxter, a Group Manager at North West Ambulance Service, said: “When people get into difficulty, the clock is ticking, the locations of the reservoirs and rivers mean it can take time for help to arrive and unfortunately it can be too late.”

United Utilities said figures from the National Water Safety Forum show most drownings in the UK occur in inland waterways rather than on the coast.

People who get into difficulty are advised to follow the RNLI’s Float to Live guidance.

Anyone who sees somebody in trouble in the water should call 999 and, if possible, throw them a life ring or buoyancy aid.

United Utilities has published a full-length version of its water safety video on YouTube at https://youtu.be/96IApgjFGCQ.