Dam almost clear of toxic algae
AN outbreak of toxic blue-green algae in the Clarrie Hall Dam, the Tweed’s main water storage, has just about disappeared, according to water authorities.
North Coast Regional Algal Co-ordinating Committee spokesman Brian Dodd yesterday announced the algal bloom in the dam south-west of Murwillumbah had dissipated even though algae has become a problem in other areas, particularly the Richmond River south of Lismore.
Mr Dodd said the warning not to swim in or use untreated water from the algae affected area of the dam had 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,” Mr Dodd said.
But he added: “Users of Clarrie Hall Dam are asked to be vigilant and keep an eye out for a recurrence of blue-green algae as the weather hots up.
“Blue-green algae usually appear as green paint-like scums on the water and foreshore edges or 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 Dodd said Tweed Shire Council was constantly monitoring the conditions in the dam and the North Coast Regional Algal Co-ordinating Committee would further advise the pub- lic if the situation changed.
Early this month the committee lifted another blue-green algal alert for the Bray Park Weir where the council draws most of the Tweed’s town water supplies.
At the time Mr Dodd said rainfall and flows in the Tweed River had contributed to the reduction of algae numbers downstream of the Clarrie Hall Dam to the weir.