Alarm raised re Platypus in Queanbeyan
Heavy rainfall in recent months has raised the alarm with two incidents involving large-scale construction sites flooding downstream waterways with mud and silt.
At the end of January prolonged heavy rain breached a temporary settling dam at the Googong township construction site sending large volumes of mud down Googong Creek and into the Queanbeyan River. The Queanbeyan River flows into Lake Burley Griffin.
At the end of February, a separate flooding incident at Major’s Creek, prompted the NSW Environmental Protection Agency (EPA) to issue Big Island Mining with an immediate Clean-Up Notice for the Dargues Reef Mine construction site.
Run off from the site’s earthworks was washed into Spring Creek, a tributary of Majors Creek, on February 24. Track construction without sediment and erosion control was identified as the culprit.
In Queanbeyan, Waterwatch volunteers raised the alarm about possible effects on Platypus downstream.
“Turbidity at this level will smother aquatic plants and gilled aquatic animals including fish, tadpoles and many aquatic invertebrates that Platypus feed on” said Dr Stephen Skinner, Waterwatch Coordinator for the Molonglo Catchment Group Inc. “The mud could also cause infilling of holes in pools and riffles that would otherwise provide egg-laying sites for native fish.”
The best immediate guess is that the Platypus moved further downstream to avoid the turbidity. A new Queanbeyan count will occur in 2014 while the latest count indicated that Platypus numbers declined following floods in 2010 and 2012.
The Molonglo Catchment Group in Queanbeyan now thinks state and council planning instruments should be changed in response to the risk of increasing numbers of severe or extreme flooding events in the era of climate change.
“They may have been applying a ‘one in 50’ or ‘one in 100’ year yardstick for flood-resistant construction, but we’re saying these regulations now need to take into account that events are happening a lot more frequently,” said Anna See, coordinator of the catchment group.
She said that CIC, which is developing Googong has been cooperating with the community group on catchment matters since the flooding event and is also talking about setting up a community liaison committee for the development.
The EPA invites members of the public to report impacts on the environment to Enviro Line on 131 555.