Heavy and widespread rainfall in the Avon catchment earlier this month has 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 will be posted on the Department’s notifications and alerts webpage.
Water Quality and Contact Recreation Alert
The public are reminded that following heavy rainfall across the catchment many pollutants from streets, gardens and farms are flushed into our waterways.
High levels of waterborne bacteria have been detected from some stormwater drains within the Swan Canning Riverpark. This can make the water unsafe for primary contact recreation.
Standard precautions are to avoid swimming for three days after significant rainfall, however with flood water still discharging, 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 when they are flowing”.
Caution should be exercised to avoid ingesting water. 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.
Pets and livestock should also be kept out of the water at this time.
Visit the Department of Health WA website for 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.
Widespread foaming and coloured water is currently being observed in the waterway as far downstream as Fremantle. The foam is caused by the breakdown of organic material.
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 related to harmful algal species.
There are no current flood warnings for the Swan River. No significant rainfall is forecast for the outlook period and renewed river rises are not expected. Information on any flood watches or warnings for the Avon River and Swan River are available from the Bureau of Meteorology.
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.
Recreational fishers and participants in the Swan Fish angling competition on 25 and 26 February should exercise caution to reduce the risk of ingesting water.
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.
Mariners are advised to navigate the Swan and Canning rivers with caution and skiers are advised to postpone any skiing activities until the flood waters recede. Visit the Department of Transport’s website navigation warnings for further information.
Parks and Wildlife is prioritising the assessment of foreshore areas affected by flood waters with local governments as river water levels decrease. 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.
Further details can be found on the Emergency WA website