Expert says seawall will destroy beach

One of the seawall options being considered by Central Coast Council

The Wamberal Beach Save Our Sand (SOS) group has welcomed opposition to a seawall as a solution to the beach’s ongoing erosion issues by University of Sydney Professor Andrew S. Short.

Short, who was also a member of the NSW Coastal Council from 2011-2018, issued a statement on September 21 saying building a seawall in today’s climate, with sea level rising and storms predicted to increase in severity and erosion, was not a viable option.

“It is at best an expensive short-term stopgap that will ultimately destroy the public beach,” he said.

“I therefore strongly oppose any seawall at Wamberal Beach, favouring buyback as the preferred option, followed

by massive nourishment.”

Short said erosion of the beach had been happening for decades with three houses lost to the sea in 1978 and houses undermined in more recent years.

“Recent research by Geoscience Australia (indicates) that since 1988 Wamberal Beach has receded at a rate of 0.2 to 0.3m each year, or 2-3m every 10 years and (is) likely to recede 20-30m over the next 100 years,” he said.

“Whist the major erosion episodes are associated with severe storm events, this ongoing recession means that each future event will erode the beach and dune further and further inland.

“In this situation the occupation of the back beach and foredune by houses is unsustainable.

“The houses are located within what is called the active beach zone, that is, that part of the beach that erodes during storm events then slowly recovers.

“With the beach receding it also means that each erosion event will extend further inland than previous events, while each recovery event will not be as wide as previously, as the whole beach systems slowly moves inland.”

Short said such a hazardous location should never have been subdivided, and anyone who purchased there post-1978 should have been well aware that the foredune is “a very erosion-prone and extremely hazardous location”.

A seawall, he said, might protect waterfront houses but would degrade the public amenity and make the beach far more hazardous during storms.

He said massive beach nourishment would help protect the houses as well as helping to maintain the beach into the future but voluntary buyback of the properties would allow restoration of the natural foredune and return Wamberal Beach to a more natural looking system.

A coastal geomorphologist and an expert on erosion and coastal processes, Short studied all of Australia’s 11,000 of beaches over a 15-year period.

He has published 11 books and over 200 scientific publications and reports and his contribution to coastal science and beach safety earned him an Order of Australia Medal in 2010.

A spokesperson for Wamberal Beach SOS, which has a membership of 3,500, said Short’s opposition to a seawall was welcome news for the group, which claims community concerns about the beach continue to be ignored by Central Coast Council.

“Since the July storms in 2020, meaningful community consultation from Council has been completely absent,” the spokesperson said.

“The current survey and prior consultation activities have provided limited scope for community members to voice meaningful debate and opinion.

“Wamberal Beach SOS calls on the Council and State Government to listen to the authoritative independent advice and abide by the legislation, to ensure any destructive impacts that this wall may have on the beach do not occur.”

Source:
Media release, Sep 27
Wamberal Beach SOS