West Beach sand carting to fix coastal erosion money down the drain
An aggressive new round of sand carting to arrest massive coastal erosion has been launched at West Beach but doubts remain that the stopgap rescue mission will amount to millions of government dollars being washed away by the next big tide.
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An aggressive new round of sand carting to arrest massive coastal erosion has been launched at West Beach but doubts remain that the stopgap rescue mission will amount to millions of government dollars being washed away by the next big tide.
Announcing the latest drive to help replenish the struggling metropolitan beach, State Environment Minister David Speirs said dune erosion was having a “significant impact” on West Beach.
“Around 100,000 cubic metres of sand is being carted from the Semaphore South breakwater as part of the government’s $5.2 million New Life for Our Coastal Environment election commitment,” Mr Speirs said
He acknowledged that the fresh round of sand carting — which costs $1 million a year — was a “short-term solution” while the government explored “long-term options” to tackle disappearing beaches.
He said the extra sand carting would run until early December, with more taking place after the holiday season.
But the government’s approach has been criticised by coastal geologist Dr Ian Dyson, who has described it as “pouring money down the drain”.
Dr Dyson, who has been commissioned by Charles Sturt Council to investigate the issue, proposes installing sandbag groynes to trap the sand instead of allowing it to drift up the coast.
The government has released its own report, completed by external environmental consultants Danish Hydraulics Institute (DHI), which outlines three “options for action” based on a 7.5-year timescale.
It has not yet settled on its preferred option but Mr Speirs said $1 million had been earmarked for research to manage beach replenishment, including new sand sources.
“The approach that is adopted will need to best meet the community’s needs and balance environmental, recreational, practical and financial considerations,” he said. The government’s 2005 Adelaide Living Beaches strategy estimated that sand loss from West Beach was 50,000 cubic metres a year.
But new modelling from DHI suggests that the annual losses are between two to three times that rate, meaning that even when current replenishment activities are taken into account there is a net annual loss of 60,000 cubic metres.
Dr Dyson said both the government’s approach and the options offered by the DHI were “a purely defensive holding operation” which would “cost a small fortune” but could not solve the growing beach erosion problem because they lacked effective sand retention measures.
He said his proposal for scientifically designed sandbag groyne fields “may not be pretty initially but would be much more effective than the fruitless sand replenishment of recent years”.
“What they are touting as potential medium or long-term fixes are not really that,” he said. “Rather than dumping ever-increasing amounts of sand, soon to be washed away, you need a more scientific approach that ensures more of the dumped sand stays where it is, helping to build up the beach profile, which has been eroded by 2m.”