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Toxic algae bloom warning for River Hamble

Public advised to avoid contact with water

21 May 2026
Riverhambleupstream

Dog walkers and visitors are being warned about a potentially toxic blue green algae bloom affecting the River Hamble, confined mainly to the Botley area. The algae has not been confirmed throughout the rest of the river, but conditions can change and users should remain vigilant

Following an alert from the Environment Agency, Eastleigh Borough Council is advising members of the public to avoid any contact with the water until further notice. Dog owners in particular are urged to prevent their pets from entering or drinking from the water.

Blue green algae can produce harmful toxins that may pose risks to both humans and animals. Reported symptoms following contact or ingestion can include skin rashes, eye irritation, blistering, stomach pain, diarrhoea, and nausea.

Anyone who believes they, their child, or their pet may have been affected after coming into contact with the water is advised to seek medical attention immediately. Pet owners should contact their veterinary surgeon without delay.

For further information, residents can contact the Environment Agency at [email protected].

Suspected sightings of blue green algae can be reported to the Environment Agency Incident Hotline on 0800 80 70 60, or by emailing photographic evidence to [email protected].

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