Article courtesy of The Sydney Morning Herald

Severe infestations of blue-green algae in Sydney’s drinking water catchments have soared 800 per cent, according to an audit which warned climate change is putting the sensitive waterways under increasing threat from toxic blooms.

The audit also called for an investigation into levels of pollution in Coxs River, which feeds into Warragamba Dam, Sydney’s main drinking water reservoir.

There are no government water quality monitoring stations in the section of the upper Coxs River that is of most concern due to a cluster of polluting businesses nearby.

A Sydney Water spokesperson said there was no risk to consumers because water is treated to meet Australian Drinking Water Guidelines.

However Professor Stuart Khan from the University of NSW said the same guidelines stress that protecting the catchment is a key pillar of providing safe drinking water.

“If we had to treat poor quality water, it would require us to use more energy and more chemicals,” he said. “Costs to treat drinking water would increase, as would the greenhouse footprint and other environmental impacts.”

The Sun-Herald can also reveal there are health concerns over the potential use of blue-green algae tainted water to grow crops in the Sydney basin.

The audit of Sydney Drinking Water Catchment was released last month, covering 2016 to 2019.