CONCERNS about blue-green algae in the Tweed catchment of Clarrie Hall Dam have now eased.

Chair of the North Coast Regional Algal Co-ordinating Committee (RACC) David Basso said the waters of Clarrie Hall Dam were currently recording low levels of blue-gree algae and the warning has been lifted.

"The recent conditions in the Tweed catchment have contributed to the reduction of algae numbers in Clarrie Hall Dam and public warnings could now be lifted," he said.

"Although the blue-green algae is not a threat on the north coast at present, users of Clarrie Hall Dam are asked to be vigilant and keep an eye out for a recurrence of blue-green algae as blooms can develop in a 24 hour period."

Mr Basso said that blue-green algae usually appeared as green paint-like scums on the water and foreshore edges.

It may also appeared as clumps throughout the water.

"Blue-green algae make the water appear dirty, green or discoloured and are generally associated with a strong musty or earthy odour," Mr Basso said.

Tweed Shire Council said it are constantly monitoring the conditions at Clarrie Hall Dam.

The North Coast Regional Algal Co-ordinating Committee will further advise the public if the situation changes.

For more information on alerts please call the states toll free information line on 1800 999 457 or visit http://www.water.nsw.gov.au