Revisit 1977 breakwater option

I refer to the many and recent contributions to the Peninsula News Forum about the ways and means to stabilise or rebuild the beach dunes from Ocean Beach to Ettalong Beach and restore the navigation channel from Half Tide Rocks to Box Head and find them all well-meaning and of value to the big picture needs.

But I also reflect on my observations of how this area "behaved" in the 12 months or so after the channel's extensive dredging in 2012.

For that short period, the dredged sands dumped to the west side of the channel on the core bank were of sufficient "height" to force most of the tidal flows via the channel and hence maintain its draft.

Further, in that 12 months, both the Ocean and Ettalong Beach foreshores remained stable and well protected because of the extra bulk on the bank.

It was then in 2015 among other heavy weather events that the tidal flow was again able to disperse over the bank and subsequently further reshape and flatten it mostly east back into the channel.

That "lost" sand has thus not been returned by benign swell to the foreshore to protect it.

For mine, consideration must be given to the "hard" option of a breakwater off Ettalong Point alongside the required navigation channel to permanently direct tidal flows to the channel and retain or prevent heavy weather damage to an extensive reshaped bank.

Yes, it may cost $10 to $20 million depending on its features and will over time require the occasional minor dredging to "reshape" the damaged bank.

Indeed, a study in 1977 listed this option as worthy of detailed review not only of the technical aspects but of cost benefits to other foreshore enhancements such as parking and boardwalks on a stabilised and expanded beach towards Umina Beach.

Email, 2 Mar 2018

John O'Leary, Booker Bay