Adelaide’s Coastal Sand Shuffle: Everything You Need to Know

Beaching plays a vital part in our Adelaidean lifestyle. Our city’s sandy coastlines provide a picturesque setting for leisure activities such as swimming and picnicking. 

But did you know that our northern beaches’ sand must be shifted to other shorelines? 

You heard that right, and if this question piqued your interest, we’ll explain the reason here! 

Why do we shift Adelaide’s coastline sand? 

Adelaide’s coastline sand needs to be shifted because of the erosion of central and southern beaches. This erosion is caused by the northward movement of sand, resulting from combined wind and wave activities.

In addition, we must shift our coastline sand, as our city’s beaches have become prime locations for infrastructure and communities.

During the early 1900s, there was a lack of comprehensive knowledge regarding the natural south-to-north movement of sand in Adelaide when the foreshore was developed with roads, houses, and other infrastructure.

As a result, the southern beaches have been eroding, prompting the need to shift Adelaide’s coastal sand as a form of maintenance.

What will happen to Adelaide’s beaches if we don’t move our coastal sand? 

If the coastal sand of Adelaide’s beaches won’t get replenished, the erosion problem will intensify and gradually spread northward. This would result in the erosion of shorelines at Henley Beach South, Henley Beach, and Grange. 

Moreover, the impact could extend beyond the beaches, posing a significant risk to coastal buildings and nearby roads, facilities, and beach amenities. The addition of storm surges to the equation could also accelerate the damage caused by erosion.

Storm surges generate intensified wave and wind energy, resulting in significant impacts on the coastline and leading to the rapid removal of sand.

Semaphore, Largs Bay, and North Haven’s dunes could expand too. 

This abnormal accumulation of sand would result in the beaches becoming overly shallow for swimming or fishing, diminishing the overall pleasure derived from these activities. 

Additionally, there’s a great chance the jetties in these areas would eventually become isolated from the water, as the sand builds up around them.

Why do we take sand from Adelaide’s northern beaches only? 

The reason we primarily extract sand from Adelaide’s northern beaches is, as previously stated, the inherent northward movement of sand along the Adelaide coastline, causing our northern beaches, such as Semaphore, to accumulate substantial amounts of sand.

If you’re worried that northern beaches would erode too, researchers have stated that the sand of these coastlines will naturally replenish in time.

Consistent trends of sand buildup following successive sand shifting were evident in the early 2000s, 1990s, and 1980s.

How are we maintaining Adelaide’s coastline?

The government allocates nearly $6 million annually to maintain Adelaide’s coastline, focusing on the central and southern areas using trucking and pumping methods.

In fact, over the past five decades, Adelaide’s eroding beaches have been sustained through the careful relocation of more than 4 million cubic meters of sand, equivalent to 1,600 Olympic-sized swimming pools.

Additionally, a financial commitment of $48.4 million has been dedicated to addressing the unique challenges faced by sections of the coastline, with a particular focus on West Beach and Henley Beach South.

This funding supports the construction of a sand pumping pipeline from Semaphore to West Beach, allowing for the efficient recycling of sand without causing road congestion from truck transportation. 

There’s also the existing sand pumping pipeline between Glenelg and Kingston Park that keeps the southern metropolitan area’s beaches from eroding.

Why can’t we build breakwaters and other structures to hold the sand of Adelaide beaches?

Constructing structures such as groynes to hold sand on our beaches isn’t a good solution to sand erosion because of their substantial cost. 

Moreover, to have a meaningful impact, these structures need extensive pre-filling of large volumes of sand from external sources. 

Without this pre-filling, there would be a risk of erosion along the coast north of each structure. 

Similar structures along Adelaide’s coast and South Australia’s other parts tend to accumulate substantial amounts of washed seagrass on the beach.

This accumulation not only negatively impacts beach usability but also leads to increased management and maintenance costs. 

What are sustainable approaches to help maintain Adelaide’s beaches? 

A sustainable approach to Adelaide’s beach management revolves around the recycling of sand from areas of natural buildup to areas experiencing erosion. 

In addition, conserving and managing coastal vegetation, like native plants, plays a crucial role in stabilizing beaches. These natural features help prevent erosion by acting as a barrier against wind and wave impact.

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A post shared by Semaphore Largs Dunes Group (@semaphorelargsdunesgroup)

Protecting and preserving natural dune systems also is vital for beach stability. Dunes act as natural buffers, absorbing wave energy and preventing inland erosion. 

These sustainable strategies allow us to protect Adelaide’s beaches without the negative consequences that structures, such as groynes and breakwaters, may bring. 

The said structures could disrupt the uninterrupted stretch of long sandy beaches that characterizes our coastline.

What is the current state of Adelaide’s sand replenishment programs? 

More sand replenishment efforts are currently underway along Adelaide’s coastline. 

In May and June 2023, around 50,000 cubic meters of quarry sand were delivered to West Beach by the Adelaide Sailing Club. 

In March 2023, another initiative involved the collection of accumulated sand from the Semaphore Breakwater. This sand, along with amassed dead seagrass (wrack), was transported by trucks and used to replenish eroded dunes at Semaphore Park. 

Similarly, sand replenishment activities occurred at Henley Beach South, where 15,000 cubic meters of quarry sand were delivered by the Henley Beach Sailing Club. 

Dune restoration efforts are also being undertaken in collaboration with local councils and communities. At Semaphore South, methods such as drift net fencing and revegetation have been employed for dune stabilization. 

Furthermore, a new foredune has been created and planted at West Beach with native plants to protect it from waves.