Severn Trent is urging people in Leicestershire to stay safe and to keep out of the water across all its visitor sites.
A number of safety measures have been put in place since their sites reopened in June including closing some footpaths and introducing one-way systems and social distancing.
The company's now reminding anyone visiting to resist the urge to cool off in the water, to avoid getting into any difficulty.
Dan Taberner, Visitor Experience Manager at Severn Trent, said: “We want everyone to enjoy the lovely weather this weekend which is why it’s so important for everyone to keep safe at our sites, and that includes staying out of the water.
“Although our reservoirs look tempting when it’s hot, the fact is they’re extremely dangerous. On the surface they look calm and steady but, underneath, the water is extremely deep with incredibly strong currents that even the most experienced swimmer would struggle with.
“On top of that, we don’t have lifeguards or areas safe to swim, so we really do need everyone to keep out of the water.”
Severn Trent say all its reservoirs are built with the sole purpose of supplying water to its customers across its entire region, and not for swimming.
“Not only are our reservoirs really deep, they’re also extremely cold,” said Dan. “If you go into any of our reservoirs, you might end up in serious trouble, and, unlike beaches and swimming pools, there are no lifeguards to help you, so please don’t take the risk.”
Severn Trent is encouraging people to check which measures are in place before travelling to any of its sites, and to be willing to turn around if the site has had to close due to becoming too full.