Posted on September 20, 2023
As communities grapple with ongoing erosion issues around the country, one state government is considering a management option with a price tag of more than $150 million.
The South Australian government launched an independent review of long-term sand management options along Adelaide’s metropolitan coastline in December last year.
The review was in response to longstanding concerns about the effects and speed of coastal erosion, and different views on how to deal with it.
An independent advisory panel has now put forward a series of options for people to have their say on — dredging, a pipeline, and keeping the status quo.
Each comes with a different estimated cost and impact.
“We’ve done extensive work and had our consultants looking into the scientific review,” panel chairman Mark Searle said.
“We started out the review and we had three main goals.
“We needed to avoid environmental harm, we needed to make sure there’s a lot of sand on the beach, and we needed to minimise disruption to all the communities along [the coast].”
Dredging would involve a vessel collecting sand from the seabed and then pumping it to West Beach or other beaches in need of sand.
The panel estimated that option would cost between $45 million and $60 million over 20 years if metropolitan sand sources — such as deposits offshore of Largs Bay or Outer Harbor — were used.
But that cost could rise if sand had to come from regional areas.
The most expensive proposal is a pipeline which would cost $140 million to $155 million — a price tag that includes construction and operational costs over two decades.
An underground pipeline would be built to transfer sand and seawater from beaches where sand is building up, including between Semaphore Park and Largs Bay, to areas like West Beach.
Status quo would cost $100m
The third and final option put forward is maintaining the current arrangement — using an excavator and front-end loader to collect sand from Semaphore and Largs Bay, and trucking it to areas where it is needed.
The option would cost $100 million to $110 million over 20 years.
Mr Searle said that if sand were not shifted, some beaches would erode to rock and clay.
“Adelaide’s beaches have to be managed to protect homes, businesses and infrastructure from storms, and to provide sandy beaches for our community to enjoy,” he said.
“It’s very important to the success of the review that it is informed by an understanding of what matters most to the community.”
Feedback on the proposals closes on Sunday, October 15.