A UNIQUE concrete seawall would be cheaper and last longer than a rockwall at Lake Cathie, its inventor believes.
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The Tideline product is the brainchild of Port Macquarie's John Nelson.
Each interlocking concrete block, which weighs just over 17 tonnes, is reinforced with stainless steel mesh, with the wall design dissipating the waves' energy.
The government-owned Manly Hydraulics Laboratory tested Tideline seawall design.
Mr Nelson estimates a Tideline wall at Lake Cathie would be about $2 million cheaper to construct than Port Macquarie-Hastings Council's preferred rock armoured revetment wall and would last three times as long.
Mr Nelson, a Tideline director, said testing showed the Tideline product could and did withstand up to a one in 500 year storm without any damage. He said a storm of that intensity would have destroyed a rock revetment wall.
Port Macquarie-Hastings Council development and environment director Matt Rogers said the claims could not be substantiated, because the product had not been used in the field and there was no data to suggest how it would perform over time.
He said the Tideline claims were opinions, while there was excellent data on the performance, maintenance requirements and construction costs of rock revetment walls.
But Mr Nelson said his opinions were backed up by extensive testing at a government-owned facility.
Tideline director Luke Ottaway said they were considering future generations, and the product would be huge for industry and employment. "It's local design and it should go local first," he said.
The Tideline wall could be built in two stages and the company is prepared to build the wall at cost at Lake Cathie.
Mr Nelson estimates 12 concrete trucks a day would be required to build a Tideline seawall at Lake Cathie or it is possible to produce the blocks on site.
He said 1000 B-double truckloads of rock would be needed to construct a rock wall and therefore the cost of road repairs should be factored into council's budget.
The Tideline representatives have a meeting with Lyne MP David Gillespie later this month and are looking to meet with NSW Environment Minister Rob Stokes.
Tideline would like to work with the council on further research and development.
Tideline's submission for the Gold Coast shoreline erosion problem has been forwarded to Griffith University for further studies.
