Civil Engineer Shane Abel has come up with a solution to ongoing erosion at Wamberal Beach which he says would be much more effective than any other method.
Abel has been working in the field of artificial surf reefs (ASRs) for more than 10 years and says the simple solution is to construct a total of 12 artificial reefs to cover the 1.5km of beach needing protection.
The exact locations would be determined on-site using sea survey and wave forecasts.
There would be 12 reefs in total, six outside (in water depths of 3m-5m) and six inside (at depths of 1.5m-2m), which would cover the 1.5km of beach required to be protected.
He said wave quality would be similar to that created by reefs in Indonesia and ideal for surfing.
“The reefs result in wave energy being removed completely from the beach under all swell conditions,” he said.
“The inner zone between the inside reef and the beach would be calm with no waves breaking and a very safe place to swim.
“The reefs over time would grow marine life and become great areas for fish to congregate in numbers.”
He has suggested two inner reefs be constructed on the southern end of the beach as a trial.
“The issue of erosion is simple wave energy,” he said.
“The solution is simple – remove the wave energy from the shore.
“Concrete retaining walls are a failed solution at a number of beaches; they are very costly and do not remove wave energy from the shore.
“The solution is to break waves off shore and this can be done by construction of undersea reefs.”
Abel said he had shared his solution with Gold Coast Council in regards to Palm Beach erosion, but that council went down the costly path of dumping a large volume of rock offshore at a cost of $18.2M.
“My reef solution would have worked better, produced high quality waves, not affected long shore drift and cost more like $10M,” he said.
“My design (features) reefs made from HDPE (a thermoplastic polymer produced from ethylene), supported on timber piles.
“The reefs are easy to construct and worst case scenario easy to remove.
“The reef design means they do not impact long shore drift being above the ocean floor and do not impact sand movement which is south-north on the east coast.
“The outer reef breaks the larger waves and the inner reef the smaller waves.
“The depth of water over the reef protects the reef from wave loading while still breaking waves.
“No-one in the world of ASR (Artificial reef design) has come up with this type of reef design.
“They have all relied on using geotextile sand bags or rocks which are all failures.
“Any suggestion to construct a concrete retaining wall along the beach will be a failure and result in loss of all sand and all of the beach.”
Abel said it would be simple to construct a trial section of the reef, no more than two 30m legs starting with a shallow reef at a cost of around $1M to $2M.
He has forwarded his idea to Central Coast Council for consideration.
Wow more destruction of the ocean ….let mother nature be . Houses shouldn’t be there …..simples. knock them down clean it up and return it to how it should have always been , a sand dune. stop fighting Nature you won’t win.
My company, West Lake Pearls Pty Ltd, has a patent pending for a modular reef made of rotomolded polyethelene drums that is secured with pilings. It is also height adjustible. It costs US$300,000 per 200m of reef. It has not been a secret since the provisional patent filing earlier this year.
Surfers have been saying this for the last twenty years.
But what would they know…
I have to agree with the “Captain” (old Goodvibes). It’s very simple, remove the wave energy further from the shore, provide a good break (or multiple), and have a safe shore line for all swimmers, AND retain the Beach, that, is “simples”.
You should be looking at Wave Swell Energy developed by the CSIRO.
It has been trailed and tested at King Island Tasmania.
Has the council responded? Seems like a no-brainer …