$155m sand pipeline proposal one of several options to keep sand on Adelaide’s beaches

A pipeline to move sand down Adelaide’s coastline to save our beaches is back on the table, and it would cost up to $155m. See all the plans here.

Keeping sand on Adelaide beaches could cost up to $155m over the next 20 years, as the state government releases a range of new options to prevent erosion.

After dumping a $38.9m pipeline last year, it on Monday revealed its shortlist of ideas – dredging, pumping, sandcarting or a combination – to move sand from Largs Bay or Semaphore down to West Beach.

A pipeline would cost up to $155m to build and operate over 20 years, running from Largs Bay down the coast. It could include dredging pump systems on Adelaide jetties.

Another option is dredging sand from the seabed for beaches in need, a project that would cost between $45m to $100m over 20 years

Keeping excavators and trucks on our beaches – the current arrangement of sandcarting by moving sand via trucks and machinery – would cost $100m to $110m over 20 years.

In August 2022, The Advertiser reported that South Australia’s coastline will need to be engineered in the future if erosion continues at its current rate.

The state government broke a contract to build a sand pipeline from Semaphore to West Beach just after it was elected and went back to the drawing board.

Independent advisory panel chairman Mark Searle said without moving the sand, some beaches would “erode to rock and clay”.

“As there is only limited new sand naturally entering the system, 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,” Mr Searle said.

Semaphore beach looking north to Largs Bay. Picture: Brad Fleet

Option one, dredging, would involve sand being collected from the seabed with a dredging vessel off North Haven and being pumped to West Beach or other beaches via a floating pipeline. Dredging could also occurre just off West Beach and sand would be moved closer to shore.

This method would cost $45 million to $60 million over 20 years if metropolitan sand sources are used, costs could rise if sand was sourced from other regional areas.

Sand could be taken from Largs Bay, Outer Harbor, Port Stanvac or regional sources and may have to be paired with quarry sand.

The second option, an underground pipeline to move sand to beaches losing it, would cost $140 million to $155 million over 20 years, which includes construction, buying additional quarry sand and operation.

A selection of images showing sand harvesting, coastal erosion and storm damage at Semaphore and Largs Bay. Supplied by Save Our Shores: Semaphore Largs Bay.

This option is a combination of quarry sand initially delivered to West Beach using trucks, and sand collected from areas between Semaphore Park and Largs Bay, either from on the beach or near the shoreline.

The bulk of the pipeline sand would be released at West Beach, but there would be other locations for sand to be delivered to other beaches.

The third and final option, maintaining the current arrangement, would cost $100m to $110m over 20 years, where sand would be collected from beaches at Semaphore and Largs Bay using an excavator and front-end loader and trucked to areas where sand is required.

External quarry sand would also be delivered using trucks on public roads.

The public can have their say and provide feedback on the three options until 5pm on October 15 via yoursay.sa.gov.au/abmr-shortlist.