Posted on March 20, 2018
By Cathy Stubbs, Daily Telegraph
The head of the Central Coast’s peak environment body has slammed calls for dredging of Ettalong channel as ill-considered amateurism with no scientific or engineering basis.
Community Environment Network chairman John Asquith said there was a real danger that some of the schemes to dredge the channel and combat ongoing erosion of Ocean Beach would cost a fortune and “put lives and property at risk”.
“Sand in the estuaries and beaches is an unstable material which is under the influence of water, waves, tides and wind and needs to be managed carefully,” Mr Asquith said.
Mr Asquith said that the movement of sand in the estuary was cyclic and constantly changing.
“Hence, dredging of the channel past Lobster Beach and Ettalong needs to be well thought out as the consequences of the wrong action could be catastrophic,” he said.
“Similarly, dealing with erosion at Ocean Beach needs experts.”
Mr Asquith said there were only two approved scientific studies of how to manage Brisbane Water estuary and Broken Bay beaches — and neither of these found any link between the siltation of Ettalong Channel and the erosion of Ocean Beach.
Mr Asquith said actions had already been taken in the area without any kind of scientific study which could now be contributing to ongoing problems. He said these included:
– Sand from the excavation of Outrigger Resort dumped to widen Ocean Beach in 2004 — which ended up in the channel to the north near Wagstaffe
– Native vegetation planted by volunteers on the foreshore to stabilise the dunes and reduce erosion was removed to improve access and views from 2008. The volunteers resigned.
– Rock wall built along Ettalong Beach up to about 2014 to prevent erosion and support a walkway.
– Sandbag wall built in 2015 at Ettalong Point at a cost of $350,000.
“Just four isolated changes, most of the works were done without studies of flows, sand deposition or long term changes in currents, sea level rise and temperatures. We need science and modelling from experts,” he said.
Council and the NSW Government need to tread carefully and develop a long-term strategy that implements the Brisbane Waters Estuary Management Plan and the Broken Bay Beaches Coastal Management Plan and does not change with every opinion,” he said.
“Otherwise, the consequences could be irreversible and expensive.”
Source: The Daily Telegraph
