Upper Hunter residents warned of blue-green algae

Locals along the Hunter River are being warned of a detection of blue-green algae.

Water NSW says testing has found high levels of the potentially toxic algae present upstream of Glenbawn Dam, between Belltrees and the upper reaches of the lake.

The alert does not apply to Lake Glenbawn.

Authorities are urging those living and working around the catchment to avoid drinking or giving pets and livestock untreated water and that recreational activities should be paused until the red alert is lifted.

The algae is known to cause gastroenteritis is consumed and skin and eye irritations from contact.