Seawalls & artificial reefs

The Gold Coast is a city built on the beachfront. We regularly replenish sand on our beaches to protect against erosion protection but we can't always rely on just sand replenishment to safeguard our coastal infrastructure from damage. Sometimes 'hard' engineering is needed to buffer our parks, buildings, and homes from damage.

The following structures help protect the coastline:

• Buried seawalls
• Groynes
• Training walls
• Artificial reefs

Buried seawalls

Large rock seawalls are buried beneath the sand along much of the developed coastline of the Gold Coast. They may be invisible to beachgoers, but our buried seawalls are the last line of defence against erosion. They are constructed along an approved alignment called the A-line, established by the Queensland Government following severe storm erosion in the 1960s and '70s.

Made of large boulders and almost 5 metres high, the buried seawalls are designed to take the brunt of large swells, to protect homes and infrastructure on top or behind them. A seawall may become exposed during significant erosion events – as happened at Hollindale Park during Tropical Cyclone Alfred in March 2025. The seawall did its job, preventing infrastructure in the park from being washed away. After these events we got to work to replenish the sand, bury the seawall and revegetate our coastal dunes.

Maintenance

We regularly check, maintain, recertify, and renew our seawalls along public areas to ensure they're ready when the next major storm hits. Sometimes we remove the dune covering the seawall so our engineers can inspect the structure.

New seawalls on private property

Constructing and maintaining a seawall for a private property is the responsibility of the property owner. For details, visit Land Development Guidelines and Coastal development works.

Groynes

Groynes are low walls or barriers built out from a beach to reduce coastal erosion. They trap the sand naturally moving north to build up the beach on the southern side. Kirra groyne is a well-known example of this hard engineering structure in action.

Training walls

Coastlines are dynamic. Our creek and river entrances would change location due to the natural movement of sand, which is why we construct training walls. Maintaining the location of creek and river entrances is important for navigation and safety for boats, flood management, erosion and water quality.

Training walls are located at:

• The Gold Coast Seaway
• Tallebudgera Creek
• Currumbin Creek
• The Tweed River Entrance

Our coastal engineers regularly check, maintain and renew our training walls to ensure they are safe and can withstand large swells and severe weather.

Sand bypassing

When the natural flow of sand has been altered by training walls or groynes, engineers need to find a way to allow sand to bypass these structures. Sand is typically moved under or around these obstacles mechanically or hydraulically to maintain natural supply.

The first bypass system was constructed at the Gold Coast Seaway in 1986 to move sand under the Seaway, which is maintained by two training walls. A 500-metre-long jetty was built at The Spit to suck up sand that accumulates near the training wall and pump it via a pipeline under the Seaway to South Stradbroke Island, where it continues to naturally move north.

A similar system was constructed to bypass the Tweed River Entrance in 2000. Sand from south of the Tweed River is pumped to several locations on our southern Gold Coast beaches. This sand pumping contributes to the world-renowned surf breaks that make up the Superbank, from Snapper Rocks to Kirra. Read more about the Tweed Sand Bypassing.

Artificial reefs

Artificial reefs have been constructed at Palm Beach and Narrowneck. They are large underwater structures built offshore to stop powerful waves from reaching and eroding the beach.

Palm Beach

Palm Beach is a four-kilometre stretch of southern coastline located between Currumbin and Tallebudgera creeks. High wave energy caused by southerly swells moving around Currumbin Rock has caused erosion over many years.

After extensive research, our coastal engineers used a combination of sand nourishment and a unique artificial reef to protect Palm Beach. The reef was built in 2019 using 60,000 tonnes of rock strategically placed on the seafloor 270 metres off Nineteeth Avenue.

The artificial reef has so far improved Palm Beach's resilience to erosion and created a much-loved surf break.

Watch how reef was constructed

To learn more, read our Palm Beach Reef brochure(PDF, 2MB)

Narrowneck Reef

Narrowneck is a narrow strip of beach that has a history of serious erosion. An artificial reef was built offshore at Narrowneck using geotextile sandbags to reduce the power of waves crashing onto the beach in 1999. The reef was renewed with more geotextile sandbags to extend its life in 2018. Monitoring shows that the reef has increased the beach's resilience against impact from storms and large swells.

Watch how the geobags were placed on the sea floor

Contact us

Got a question? Email us at beaches@goldcoast.qld.gov.au