A councillor is calling for extra police patrols at an “algae-infested” lake before a child is hurt.

Cally Gale fears it is only a matter of time before someone is badly injured or drowns, after the hot weather has been enticing teenagers to jump into a lake at a new Bellway housing development.

The mum is urging the developers and police to work together to help prevent an accident at the site in Tiltman Avenue, Greenhithe.

Cllr Gale (Con) who represents Greenhithe and Knockhall on Dartford Borough Council, said: “The developers actually have a legal responsibility to ensure Keep Out signs are clearly placed around the lake on their land.

“They have agreed to order some signs but have said they could take up to eight weeks to arrive.

“They have also said they will send security patrols to patrol at the weekends.”

Cllr Gale is particularly concerned about the dangers of what she describes as a “toxic sludge pool” next to the lake.

“The children could get all sorts of diseases in there,” she said. “It is just stagnant water. It’s full of algae, possibly chemicals from the site and the smaller pond is a muddy sludge.

“I checked and there are no ‘keep out’ signs.”

She added: “I really hope no one gets hurt. I know it may seem like a good game but these things can go horribly wrong, usually for the youngest participants.

“They could get sick from the algae or the chemicals. It’s murky. They can’t see what’s at the bottom or how shallow or deep it is.

“They could get trapped in reeds. Someone could drown.”

The youngsters are said to be gathering in large groups in the evenings once the site is closed.

Cllr Gale is demanding for an increase in police patrols at those time.

A spokesman for Kent Police said: “Kent Police is aware of recent incidents of people entering the lake near Tiltman Avenue, Greenhithe.

“Officers are working with partners and the site developer to prevent this, which includes the use of increased patrols in the area.”

Inspector Nicholas Grainger, of Dartford’s Community Safety Unit, said: ‘With the warmer weather, longer days, and school holidays approaching, there may be a temptation to enter bodies of open water to cool off.

“However, by doing so, people are exposing themselves to dangers, some of which are invisible. We ask that you remain safe by staying out of the water and calling 999 if you see someone in trouble.”

“Hazards in open water expanses are not always easy to see, such as contaminated water due to pollution or chemicals...”

Gravesend’s RNLI issued a warning about the dangers of lake swimming as the weather heats up and people look for an easy way to cool off.

Water safety officer, John Robinson, said: “The attraction of an open water or wild swim in a cool river, lake or open water expanse may be very appealing on a hot summer day, however entering the water must be considered carefully as the potential risks of danger or harm can be very serious.

“The air temperature may be very hot, however an area of open water will usually be far colder, and 'cold water shock' is a very real danger which can quickly lead to a failure to use arms and legs to stay afloat or swim effectively.

“Those entering the water must also consider the potential for submerged hazards in rivers, lakes or open water expanses, which can easily trap swimmers or cause injuries where underwater hazards may be sharp or jagged.

“Other hazards in open water expanses are not always easy to see, such as contaminated water due to pollution or chemicals entering the water, these can cause serious and sometimes long-term health complications.”

If someone is in difficulty near the coast or River Thames, call 999 or 112 and ask for the coastguard. For inland lakes call Kent Fire and Rescue Service.