Authorities warn of water discolouration in Swan and Canning rivers following heavy rain

The Swan River. Picture: Bloomberg via Getty Images
The Swan River. Picture: Bloomberg via Getty Images

A SURGE of freshwater from the Avon catchment has brought heavy loads of nutrients, organic matter and sediments into the Swan and Canning rivers prompting authorities to urge people to stay away from discoloured water.

Department of Parks and Wildlife’s river systems manager Mark Cugley said State Government agencies were keeping a close watch on conditions in the Swan Canning Riverpark with more unseasonal rains forecast this week.

“This could lead to further discolouration, with foam becoming visible in parts of the river, associated with the break-down of organic matter,” Mr Cugley said.

“Currently there is discoloured water visible downstream to Fremantle on outgoing tides.

“The Health Department has general advice for people not to swim in the rivers for at least three days following significant rainfall.”

Mr Cugley said there was an important connection between the Swan Canning system and the outer Avon catchment that extends more than 125,000sq km, but which is not always hydraulically connected to the Riverpark.

“Because of the unseasonal influx of so much freshwater, we can’t precisely predict how the river system will react when the weather resets to normal summer conditions,” he said.

“That’s why Parks and Wildlife will keep a close watch on the developing situation through our weekly water quality monitoring and with extra sampling and patrols.”

People are encouraged to visit the Department of Health’s website Tips on Healthy Swimming at: http://healthywa.wa.gov.au/Articles/S_T/Tips-for-healthy-swimming

Riverpark alerts can be found on the Parks and Wildlife website at www.dpaw.wa.gov.au/management/swan-canning-riverpark.

Incidents within the Riverpark can be reported on 9278 0900 or afterhours on 0419 192 845.