Rising sea levels and more frequent storms are increasing the rate of erosion across Australia’s southern coastline, the CSIRO has said, while locals at one Victorian beach are concerned it is not safe for summer holidaymakers.
Kathleen McInnes, a CSIRO sea level and coastal extremes expert, said more powerful waves were also contributing to the problem.
“Sea levels have risen some 20 centimetres over the past 100 years, and are currently rising at about three millimetres per year,” she said.
“There is also evidence that winds in the southern ocean are intensifying and this is driving a positive trend in wave energy reaching our coastline.
“So this is creating a double whammy for coastal impacts.”
Individual storms have also become more frequent and intense, meaning beaches do not have as much time to recover after a harsh winter.
“They’re driving higher waves which means a higher wave energy [is] reaching the shore,” Ms McInnes said.
The beachfront at Point Lonsdale, on the Bellarine Peninsula, has been badly eroded over the past decade and local residents said there was a risk children could slip near the seawall.
James Cotton, founder of local community action group Save Point Lonsdale Front Beach, said residents wanted the beach renourished with sand before the peak holiday season hit.
“The whole of Point Lonsdale revolves around this front beach,” Mr Cotton said.
“It is where everyone comes to gather, [and] goes to the beach, which has become very difficult in recent years.
“The residents are so concerned about this they’ve agreed to fund this if the council won’t.”
But the group is still waiting for an answer from council before going ahead.
Efforts to stop erosion ‘have had little impact’
The Department of Environment, Land, Water and Planning (DELWP) said the Point Lonsdale area had always been a dynamic environment where sand had come and gone for decades.
DELWP’s Frances Northeast said an independent review of efforts to counteract erosion along the beachfront had found engineering solutions at the beach had been ineffective.
Three groynes, each 50 metres long, sit along the foreshore, and $450,000 has been spent on managing the erosion since 2010, but it has had a limited impact.
“If we put in any kind of structure, it’s like a lever,” she said.
“We’re going to impact somewhere else. So they’re the types of things we have to consider.”
Planners need to prioritise which areas to save
Ms Northeast said erosion along the Barwon south-west region was challenging to manage.
“We’ve got erosion from Point Lonsdale, all the way down to Apollo Bay and down to Portland as well,” she said.
Ms Northeast said short-term solutions included sand relocation and bringing in new sand to badly eroded beachfronts.
“In the long term we have to work out what our coastal hazards are and which assets are important. We have to look at our priorities,” she said.