Why the Gov't should not be considering a sand pipeline from Semaphore/Largs Bay to West Beach

My name is Maggie Gordon and I have been a Largs Bay resident since 1975. I am one of the founding members of the Semaphore Largs Bay Dunes Group and one of the two SLDG representatives on the Adelaide Coastal Communities Alliance. ACCA was formed last year to seek alternatives to the proposed environmentally harmful West Beach to Semaphore/Largs sand pipeline. It is made up of the environmental groups stretching along the coastline from North Haven to Henley.

I primarily wish to discuss the Semaphore and Largs Bay coastal environment, one that I have closely observed over many years. In particular, I wish to describe the harmful effects incurred by the Department of Environment and Water’s sand carting program over recent years. This program was instigated in an attempt to solve West Beach’s large-scale erosion problems (caused by the building to its south of two large breakwaters in the 1990’s). Its underlying concept was that the sand had been removed from West Beach by the littoral drift along the coast and neatly deposited on our northern beaches. This is only partially true. Only a small portion is deposited between Semaphore and Largs Bay jetties, which was the main area chosen for sand carting and also the peninsula’s premier beach. A large proportion is deposited either on sand bars off the coast or on the new beach formed at the tip of North Haven. Also, all sand taken in the littoral drift is ground down by this process into smaller grains, rendering all the Lefevre Peninsula sand unfit for West Beach restoration. At the end of each year this finer sand has been washed back off West Beach into the sea. Some West Beach residents have even complained about this fine sand being blown into their gardens and houses.

However, not only did the sand carting program not solved the West Beach erosion problem, it also caused serious erosion problems along Lefevre Peninsula, particularly at Semaphore and Largs Bay, the two beach areas targeted in sand carting. I include two photos to prove my point. Since the program began, we have lost 8-10 metres of our foredunes. These all-important erosion buffers no longer gently slope down to the beach in their natural formation. Instead, they terminate in fragile cliff-like erosion scarps, ready to collapse further at the slightest disturbance.

This is because the program's large-scale and prolonged removal of sand from the beach has resulted in a lowering of the beach level allowing wave surges in any severe storm event to flow further up the beach and cut into the exposed face of the foredunes. The foredune, for example, in front of the Semaphore Palais has already been breached as a result of sand removal (See red arrow in bottom photo}. If this approach is continued, Adelaide may well become notorious as the only coastal city in the world to be busily engaged in lowering its coastal beaches in an era of climate-induced sea level rise. It is vitally important that our dune system remains robust and able to protect the low lying hinterland of the Lefevre Peninsula.

This is why ACCA is strongly opposed to the building of a sand pipeline which would remove enormous quantities of sand from Semaphore and Largs Bay beaches for a 20-year period in the first instance, with every likelihood that the process would continue once it has become the accepted approach. It would also entail for prolonged periods the presence of large trucks on the beach with their polluting noise and fumes as well as an even noisier sand collection unit - which resembles nothing so much as a noisy and dangerous industrial facility in the middle of what is meant to be a peaceful beach (See photo of Glenelg SCU).

ACCA has been actively exploring alternatives to the proposed pipeline and has forwarded these to the S.A. government’s Sand Management Review which has just begun. These include world best practice methods of sand restoration and a detailed appraisal of South Australia’s many sand sources. The basic premise is that Adelaide’s beautiful metropolitan beaches should not be used as a sand source. They are too valuable an asset to the wider Adelaide community to be wantonly squandered in a pointless and destructive exercise.