Scorching summer temperatures have caused an explosion of toxic algae in British lakes.

In Cumbria, blue-green algae, also known as cyanobacteria, has been found at four locations - Windermere, Ullswater, Coniston Water and Killington Reservoir.

Other lakes found with blooms of the algae include Pennington Flash country park, near Leigh, Greater Manchester.

George Leeks (sunglasses) and Nick Bishop (in the boat) from the Stillwater management company clear algae from 'Little Britain' lake on the River Colne in Hillingdon, West London

The toxic algae, which flourishes in sunlight, can trigger skin rashes, nausea, vomiting, stomach pains, fever and headaches in humans.

It has also been linked to serious illness such as liver and brain damage, according to Welsh health officials.

Children are at greater risk than adults of developing problems because of their comparative lower body weight.

Blue-green algae has also been blamed for the death of some animals.

Cumbria is currently in the midst of its worst hosepipe ban for six years and water availability is becoming such a problem that one utility company is considering using the infected water from the lakes.

United Utilities declared on Monday that seven million residents in North-West England will face water shortages and the hosepipe ban will be enforced, with a maximum penalty of £1,000 ($1,300).

Earlier this week, the Environment Agency urged all swimmers to avoid four of Cumbria's famous lakes – due to the potential deadly algae.

Blue Green Algae flourishes in sunlight, and four Cumbrian lakes have become infected with the deadly organism. It has the potential to kill pets and make humans seriously ill

At Coniston, a notice issued by the parish council reads: ‘It’s tempting to swim in this heat but you put your health at risk. Same for dogs, it can be deadly.'

The algae, called cyanobacteria, naturally occurs in inland waters, estuaries and the sea but deadly toxic blooms can form in hot and sunny conditions.

Water affected by blue-green algae may be green, blue-green, or greenish brown, and can produce musty, earthy or grassy odours.

People who swim or swallow algal scum can suffer from skin rashes, eye irritation, vomiting, diarrhoea, fever and muscle and joint pain.

Public Health Wales warns: 'Blue-green algae are capable of producing several different toxins. People may be exposed to these toxins through contact with the skin (e.g. when swimming), through inhalation (e.g. when motor boating or water skiing), or by swallowing contaminated water.

'These toxins can cause skin rashes, nausea, vomiting, stomach pains, fever and headaches.

A stretch of the Grand Union Canal at Little Venice in West London that has turned green

'Occasionally they can cause more serious illness such as liver and brain damage.'

It has also warned dog walkers to stop their pets from running into affected lakes and rivers, as symptoms can emerge 'within hours' of contact.

Exposed animals can suffer from diarrhoea, seizures, vomiting, which can eventually lead to death.

Fiona, a vet local to an affected lake in Ullswater, explained the BBC why pets are more likely to suffer toxic symptoms over humans.

She said: 'Within hours it can damage the liver and cause diarrhea, seizures and vomitting. Dogs, in this heat, are more likely than us to ingest the toxins.

'They are drinking it, swimming in it.'

Despite this, United Utilities are hoping to use the water from the infected Ullswater and Windermere lakes in order to top up their dwindling supplies.

The firm hopes to filter out any harmful chemicals produced by the algae, but has yet to release information regarding their processes.

The firm has confirmed it has applied for drought permits for the two Cumbrian lakes and a drought order for a third - Ennerdale Water.

Water companies can make drought applications if public water supplies are at risk, but this is the first time it has been done since 2010.

Martin Padley, United Utilities Water Services Director, said: 'The reducing raw water reservoir levels are not surprising given the ongoing lack of rainfall.

'Applying for drought permits is not a decision we have taken lightly.

'We are working closely with the Environment Agency, to ensure that water supplies are protected for both customers and the environment.'

The company must ask the Department for Environment, Food and Rural Affairs (Defra) for permission to increase its abstraction of water from Ennerdale Water as it feeds the River Ehen, a Special Area of Conservation.

WHAT IS THE DEADLY ALGAE? Blue-green algae is a type of bacteria (called cyanbacteria) that shares some of the same characteristics as plants. Blue-green algae exists all over the world and is found naturally in many inland waters, estuaries and the sea. Blue-green algae generally grows in lakes, ponds, and slow-moving streams when the water is warm and enriched with nutrients like phosphorus or nitrogen. The algae is very small and can’t be seen with the naked eye unless it is concentrated into clumps. It tends to look like green flakes, greenish bundles or brown dots in the water. When environmental conditions are just right, blue-green algae can grow very quickly. It is buoyant and floats to the surface, where it forms scum layers or floating mats. An extensive growth is sometimes referred to as a bloom. What are the health risks? Blue-green algae is capable of producing several different toxins. People may be exposed to these toxins through contact with the skin (e.g. when swimming), through inhalation (e.g. when motor boating or water skiing), or by swallowing contaminated water. These toxins can cause skin rashes, nausea, vomiting, stomach pains, fever and headaches. Occasionally, the toxins can cause more serious illness such as liver and brain damage. Children are at greater risk than adults of developing problems because of their comparative lower body weight. How can the health risks be minimised? Not all blue-green algae blooms and scums are toxic but it is not possible to tell from appearance and so it’s best to assume they are harmful and take the following precautions: Do not swim in the water

Do not swallow the water

Avoid contact with the algae

Do not eat fish caught from the water

Observe and abide by any warning notices positioned around the water Anyone who has come into contact with water containing blue-green algae should shower with fresh water immediately. Anyone who has come into contact with affected water and has become ill should obtain medical attention. Source: Public Health Wales Advertisement

If the Secretary of State for Defra grants this drought order, it will allow the company to continue to take water from the site in order to help safeguard public water supplies within the West Cumbria Resource Zone.

Jim Ratcliffe, Environment Agency Drought Manager, said: 'Following the prolonged dry weather in the North West, United Utilities is asking to take more water from the lakes than the previous limit allowed which was in place to maintain levels that people enjoy, protect the environment, ecology and wildlife.

'We are currently checking whether we have all the information we need to begin to determine these applications.

'Any drought permit would only be issued to United Utilities after public consultation and a review of all the available hydrological data.

'The water resources situation could also improve if demand for water reduces or if enough rain returns to replenish supplies.

'The Environment Agency will always balance the needs of the public, businesses, industry, farmers and the environment.'

Found in Ullswater, Windermere (pictured), Killington Lake and Coniston Water, the algae, called cyanobacteria, naturally occurs but deadly toxic blooms can form in hot and sunny conditions. Water affected by Blue Green Algae may be green, blue-green or greenish brown and can produce musty, earthy or grassy odours

The official confirmation followed reports of the algae first being spotted in Coniston Water at the start of July.

On June 29th, Northern Ireland Water put a hosepipe ban in place.

Now seven million residents in the North-West of England have been told by United Utilities they too face a ban starting on August 5.

This would be the first ban to hit England since 2012 when restrictions were brought in by seven water companies, covering 20 million customers.

Utility firms have been slammed for putting profits before fixing water-wasting leaks. despite Brits struggling through the most severe heatwave since 1976 - with temperatures hitting a 2018 peak of 33°C (91.4°F).

And household water bills rose by 40 per cent above inflation from privatisation in 1989 to 2015, according to the National Audit Office.

Water firm United Utilities said it had no choice to clamp down on domestic customers as they have struggled to supply demand in the UK's longest heatwave in four decades.