A wave energy generator that partially sank off the South Australian coast four years ago will be dismantled and its submerged portion converted into an artificial reef.
But the local mayor is seeking assurances that the remnants of the wrecked machine do not become a hazard to local boat users.
Since March 2014, the $7 million Oceanlinx unit has been a constant feature of the coast off Carrickalinga — south of Adelaide — and fallen into disrepair.
There has been lengthy debate on what should become of the 3000-tonne eyesore, which has been kept off limits to water users.
“They certainly don’t see it as something that beautifies their outlook across the sea,” Yankalilla Mayor Glen Rowlands said.
Locals were initially told it would be removed within a year, but the process was delayed by legal proceedings.
“There was a survey that went around to gather some sort of consensus from the community as to what they would like to see happen,” Mr Rowlands said.
“Council’s approach was we would like it cut down and totally removed, and when I say removed [I mean] brought to shore and transported away.
“[But] that would have been an extremely expensive exercise.
“The locals knew straight away that it was going to become a reef in its own right the longer it stayed there.
“So I’m not surprised, and I don’t think the community’s surprised. The approach is to cut it down under the water line and let it become an artificial reef.”
Infrastructure Minister Stephan Knoll said helping a reef to flourish was the “best balanced option” that would “promote fish life in and around that area”.
He said the cost of the project would run into the “many, many hundreds of thousands of dollars”.
“We took the decision that the best approach was to get rid of the eyesore above the water, keep the structure that’s below the water for fish and other marine life, and then make sure the appropriate safety beacons are in place,” he said.
Structure’s removal put out to tender
In March 2014, the structure was being towed from Port Adelaide to Port McDonnell in the south-east, where it would have used oscillating water column technology to generate enough energy to power about 1000 homes.
Instead, it started tilting after its airbags were damaged and the unit sank while being towed to shallow water.
Shortly afterwards, Oceanlinx, which previously had a generator sink offshore at Port Kembla in New South Wales after it broke free from its pylons during rough seas in 2010, went into receivership.
The state government has now put the job of scrapping the Carrickalinga structure out to tender.
Warning lights will be installed around the concrete structure below the surface.
According to the tender document, the successful contractor “shall remove all materials above the submerged deck level … except for the existing steel crane base and the concrete base on which the crane is mounted”.
The submerged deck sits approximately one metre below the water at low tide, the document states.
But Mr Rowlands said local boaties would want guarantees that it would not become a hazard.
“They may be concerned if it is something that they have to be very vigilant about keeping away from,” he said.
“Whoever fixes this problem up, they may have a criteria that it has got to be X amount of metres under the water. I don’t know.”