All visitors and their dogs are advised to stay out of the water at Carr Vale Pond, Bolsover following the identification of blue-green algae.
Blue-green algae is a naturally occurring organism which is more common in ponds during hot weather. The algae can produce toxins which may be harmful to animals and cause rashes and illness in people.
Derbyshire County Council say they are working with the Environment Agency and Carr Vale Angling Club to understand the problem and install signage to warn visitors. Carr Vale Angling Club have closed the pond to anglers.
If you or your dog have been in contact with the pond water recently and are concerned, you should seek advice from your GP or vet.
Derbyshire County Council’s interim assistant director for environment, Claire Brailsford, said: “Many areas of water are susceptible to blue-green algae during the warm summer months. It can persist for several weeks but usually disperses naturally when the weather gets colder.
"Blue-green algae is not always harmful but as a precaution, we are advising people to keep dogs out of the pond water until further notice.”