Too early to gauge if reef stopping erosion

The Dalek-like concrete reef was installed at CY O’Connor beach a year ago.

RESEARCHERS say it’s too early to tell whether an artificial reef installed at CY O’Connor beach a year ago has been successful in reducing erosion.

The engineered fringing reef was a “nature-based” solution pioneered by Henderson marine engineer group SubCon. 

The 135 Dalek-like concrete structures were stationed 100 metres offshore to slow down wave energy,  helping minimise the need for expensive sand replacement and beach closings. 

It’s also hoped the reef structures will provide a habitat for sea life and encourage greater ecological diversity. 

The project cost over $500,000, but Cockburn council was already paying similar amounts trying to keep ahead of the erosion through dune rehabilitation, relocation of walkways and other restorative works.

After being contacted by locals who believed they could still see the beach disappearing, the Herald contacted researchers at the UWA Ocean Institute who are monitoring the trial.

Coastal engineer and institute postdoctoral researcher Renan Silva said not enough data had been collected to pinpoint any erosion patterns, but he remained optimistic about the project.

“The artificial reef is new MMA technology, equipped with pressure sensors for currents and waves,” Dr Silva said.

“Data that was recently received was not straight forward, so there are no real results yet.

“We require more data.” He said that while erosion was a natural occurrence, increasing erosion was a global trend. 

The Herald spoke to several regular beachwalkers who had different takes on whether the reef was working, most aware of the trial.

“I know of the artificial reef project. It’s good to see action being put into our ocean health,” said one walker.

“There’s a lot of erosion even since yesterday just over here (CY O’ Connor). It’s worse next beach up and even South Beach.”

But another walker at Catherine Point was less concerned: “It’s always chopping and changing. I think it’s always been like this, it’s nothing to worry about”.

“Its a wonderful beach, I wouldn’t be anywhere else.”


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