Heavy and widespread rainfall in the Avon catchment during February resulted in unusually high flows into the Swan Canning Riverpark. Below is an update from the Department of Parks and Wildlife on how we are responding to these conditions. Regular updates to the public are being be posted on the Department’s notifications and alerts webpage.
Incident Management Team
A flood response Incident Management Team has been regularly meeting since 6 February to coordinate Parks and Wildlife’s response to the flood events and in preparedness for any future incidents that may emerge such as algal bloom or fish death incidents.
Contact recreation advice
The effects of the February flooding are beginning to diminish, however there may still be areas of the Swan Canning Riverpark with elevated levels of waterborne bacteria.
The Department of Health’s advice is to: “avoid swimming or other forms of primary contact recreation in water that is discoloured, murky or smells unpleasant and next to stormwater drains particularly if they are flowing”.
Primary contact recreation includes swimming, jet-skiing, water skiing, windsurfing, diving, or any other activity in which the whole of the body or the head or trunk of the body is fully immersed.
Visit the Department of Health WA website for more information about Swan and Canning rivers bacterial monitoring and tips for healthy swimming.
Waterway monitoring is being undertaken weekly. Reports on microalgae activity and environmental conditions in the Swan and the Canning rivers can be found on the Parks and Wildlife website.
Riverpark notifications and alerts will be used where algal species occur at concentrations that may be harmful to aquatic life or human health and requires public advice. There are no current alerts for the Riverpark relating to algae activity.
Low oxygen conditions are affecting wide areas of the lower Swan and Canning rivers (see image below). These conditions are heightened by saline bottom water and fresher surface waters not mixing (more info here). The low oxygen conditions are already thought to be affecting crabs and other invertebrate fauna and fish deaths could occur in the affected areas. It is expected that these conditions will remain in place for some time and may proliferate upstream. Members of the public are encouraged to call FishWatch 1800 815 507 to report any dead or sluggish fish in the Riverpark.
Standard Department of Health advice is that the public should not consume wild shellfish (eg: mussels and cockles) from the Swan Canning Riverpark, as the quality cannot be assured. The Department of Health issues warnings regarding the consumption of fish, prawns or crabs from the Swan and Canning rivers. Please contact the Department of Health WA for further information.
Fishers may have noticed the die-off of mussels in the lower estuary. This is a natural phenomenon that occurs when freshwater flows affect the mussels, which prefer more saline water. Mussels are expected to recover in time.
Parks and Wildlife officers continue to inspect the river for floating navigation hazards and are removing these hazards where possible. A number of navigation warnings have been issued by the Department of Transport regarding damaged navigation aids.
Visit the Department of Transport’s website navigation warnings for further information.
Some parks and roads adjacent to the river have been closed and people should contact the relevant local government for further information.
Parks and Wildlife officers are currently observing large accumulations of seagrass wrack at some popular Riverpark recreation areas. The seagrass die-off at this time is likely a response to changing environmental conditions (e.g. light and salinity) associated with the flood flows. Seagrass is a natural and important part of the river ecosystem and seagrass meadows are expected to recover from this event. Management actions will be assessed in conjunction with local riverfront councils.
The Department of Health is warning people to take precautions against biting insects following the recent widespread rainfall and flooding events across Western Australia. Visit the Department of Health’s website prevent mosquito bites at home for further information.
Emergency information can be found on the Emergency WA website.
Link to website alert.