Denmark's watershed

Water in the Denmark River can be used as a drinking source for the first time in more than 40 years after a major reduction in salinity.

Water Minister Bill Marmion visited the Denmark Pipehead Dam on Sunday to announce the news.

It is believed to be the first time a river’s salinity levels have been reversed to such an extent in Australia.

The river, which feeds into a 440 megalitre dam that was originally Denmark’s primary water source, has been returned to drinkable quality in line with World Health Organisation guidelines, and will support the Quickup Dam in supplying water for the town and surrounding areas.

“This is the first river in Australia, potentially the world, that has been reduced in salinity to the degree it is potable again,” Mr Marmion said.

The river’s saline levels, monitored upstream at the Mt Lindesay gauging station, were consistently as high as 700 micrograms/litre in the 1990s.

Monitoring this winter recorded levels as low as 300 micrograms/litre, which is well below the accepted level of 500 micrograms/litre for drinking water.

Mr Marmion said much of the drop in salinity could be attributed to the dedication of farmers and the Wilson Inlet Catchment Committee to revegetate catchment areas upstream.

Denmark Shire chief executive Dale Stewart said it was a good outcome.

“The water quality of Denmark River is improving every year, with the prediction that it will become potable without treatment in coming years,” he said.

On Sunday, Mr Marmion also announced Denmark’s 15 gigalitre water tank, commissioned last year, would operate at full capacity for the first time this summer.

The tank can supply water for the entire town for up to six days, a dramatic increase from the former tank, which could only supply Denmark for 24 hours in the event of a power outage.