Everything you need to know about how Adelaide’s beaches are managed

Adelaide’s beaches are a significant part of the lives of many South Australians, so it is important to protect the coastline and make sure it can be enjoyed by everybody.

The coastline plays a key role in protecting Adelaide from the effects of rising sea levels and extreme storms and the various dune systems also play an important role in conserving biodiversity.

Sand has been moved around Adelaide’s beaches for 50 years. This is because the coastline is one connected beach system, with sand naturally moving north due to a combination of wind and wave activity.

This causes erosion on our central and southern beaches, such as Seacliff, West Beach and Henley Beach South, and results in sand building up on Adelaide’s northern beaches, including Semaphore and Largs Bay.

The natural sand drift means recycling sand in Adelaide’s beach system and adding sand from external sources is vital to avoid some of our much-loved coastline eroding to rock and clay.

Quarry sand is also trucked onto West Beach to help restore the beach’s dune system, protect infrastructure and improve amenity at central beaches, including Henley Beach South and Henley Beach, to support the coastal communities and businesses.

Why can’t Adelaide’s coastline just be left alone?

Adelaide’s roads, houses and other infrastructure were built along the foreshore in the early 1900s, before it was commonly understood that Adelaide’s sand naturally moved south to north, causing the ongoing erosion of the southern beaches.

Maintaining a stable coastline by recycling sand allows us to enjoy sandy beaches, as well as saving South Australians from the costs of damaged assets and infrastructure.

Why does sand need to be shifted?

From all the studies and evidence there are two clear conclusions. The most practical and cost-effective ways to deal with erosion on our southern beaches are to: recycle sand from Adelaide’s northern beaches, and bring in additional sand from external sources.

About 1.5 million cubic metres – or 600 Olympic-sized swimming pools – of offshore sand was imported between 1988 and 1998 from Port Stanvac and other sources.

This imported sand was a necessary top-up to counteract sand losses from the beach system and the impacts of rising sea levels. A top-up every now and again keeps Adelaide’s long beach system healthy.

Importing external sand can be challenging. It’s a scarce resource and has significant costs. This means we have to carefully manage the sand we have, and continue to recycle it within Adelaide’s beach system.

Independent Adelaide Beach Management Review

The state government commissioned an independent review into the management of Adelaide’s beaches to ensure a long-term solution could be found.

Following more than a year of investigations, the Adelaide Beach Management Review Independent Advisory Panel Report made 2 key recommendations:

• Investigate the feasibility of dredging nearshore as a long-term, sustainable method to recycle sand.
• West Beach should be restored with 550,000m³ of sand within 5 years.

West Beach

Works to replenish West Beach with additional quarry sand will commence on Monday (July 29) in line with the recommendations of the Independent Adelaide Beach Management Review.

The works will combat erosion, protect infrastructure and improve amenity at central beaches, including West Beach, Henley Beach South and Henley Beach, to support the coastal communities and businesses.

Trucks will access the beach via the Adelaide Sailing Club and deliver the sand between there and an area just north of the West Beach Surf Club.

The works will occur between 7am and 5pm Monday to Friday, subject to weather conditions, storms and operational requirements.

The public will have access to the beach while the works occur but people should take care during works and comply with safety signage. There will be no works on weekends, public holidays and during school holidays.

West Beach will be boosted with 200,000 cubic metres (m³) of quarry sand over the next 12 months following the review’s findings.

Dredging Trial

As announced in May 2024, the State Government is working to conduct a dredging trial to recycle sand that drifts north along Adelaide’s coastline. The government is currently collecting all the data required to finalise an application to the Environment Protection Authority (EPA) for approval before the trial to occur,

The trial aims to dredge up to 90,000 cubic metres (m³) of sand from a nearshore zone between Taperoo and North Haven and deliver it south by barge to West Beach, where it will be placed near the shoreline using different options.

It aims to confirm if dredging can be used as a long-term, sustainable solution to recycling sand within the beach system.

The dredging trial would be expected to run for about 8 weeks and be completed by early November 2024.

Beach safety

Sand movement works on Adelaide’s beaches are undertaken by a contractor on behalf of the department.

The Department for Environment and Water and its contractors take safety very seriously and measures are always in place to protect the public and animals.

Trucks on the beaches must stop within 10 metres of any person or animal.

While on the beach, trucks have a speed limit of 25km/h between 10 metres and 50 metres of any person or animal. When no people or animals are within 50 metres, trucks can move up to 40km/h.

Glenelg to Kingston Park

Sand is transferred from Glenelg to Kingston Park via 7 kilometres of underground pipeline. Sand is scraped from the beach surface in thin layers using a land plane and brought to a temporary fenced work area where it is screened to remove stones, beach wrack and other debris.

Then it is mixed with seawater before being pumped south through the pipelines to the southern beaches. It is then discharged at the back of the beach, at the toe of the dune or the base of seawalls.

The sand settles out from the seawater forming a low, wide stable mound and the excess seawater returns to the sea.

When sand has built up at one discharge location, the sand and seawater mixture is redirected to another discharge location.

Waves and tides disperse the sand, and the wind and waves slowly moves the sand northwards (known as littoral or longshore drift). This keeps our beaches sandy and provides foreshore protection.

Why not build structures, like groynes, to hold sand on our beaches?

Structures like groynes, breakwaters and seawalls can be used where appropriate to help trap sand and protect infrastructure.

Groynes are structures built across a beach, usually on the coastline into the water, to trap sand. Small groynes are useful for raising beach levels on a small scale.

But to manage Adelaide’s coastline well, groynes are not the answer. They are costly to install, require large quantities of sand, are visually unappealing and can cause the coast on the northern side of the structure to become starved of sand.

By focusing on sand shifting for protection of Adelaide’s beaches, long sandy beaches can be achieved without the additional cost and side-effects of expensive structures.