Surfpolitik Large erosion expected on NSW beaches

In: Surfpolitik by Stu Nettle 39 Comments Tue 5th Jun '12

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High tide in Sydney is at 9pm sharp tonight. Tomorrow night it's fifty minutes later. During both instances the tide peaks at approximately two metres making them among the largest high tides of the year. Those tidal peaks combined with the forecast large south-east swell are set to buffet any exposed beach vulnerable to erosion.

In Sydney Cronulla and Collaroy/South Narrabeen are open to the south-east and both are prone to erosion. Last year construction work at the Prince Street wall at Cronulla was finished to bolster the foundations that had been undermined by continual erosion. At present it's surrounded by a large bed of sand offering protection.

At Collaroy the risk is private property being lost to sand erosion. Fortunately, like Cronulla the properties at risk currently have a large sand buffer. Ongoing remedial works by Warringah and Pittwater Councils have the beach in the best shape for a decade. It's well prepared to cope with the expected barrage.

Wamberal and Norah Head, both on the NSW Central Coast, are places that have experienced terrible erosion in the past. Cabbage Tree Bay at Norah Head in particular had problems recently though a structure was built at the base of the cliffs last year. This event will be its first decent test.

On the mid north coast, a multi purpose reef has been proposed at Old Bar near Taree. The solution was devised after three homes were lost at Old Bar in 2008. If built the reef would be constructed offshore to mitigate wave energy and halt erosion on the shoreline. At present the coastline remains vulnerable.

Further up the coast Byron Council has a planned retreat strategy in place for threatened homes at Belongil Spit. The council wont aide property owners during storm events but it will allow them to reinforce their own properties as long as any materials are removed at the owners expense after the event. Fortunately for them the swell isn't well aligned for Byron and will be significantly smaller than the southern NSW coast.

The NSW east coast has had six months of below average swell activity with a noticeable absence of large swell events. This has provided surplus supply of sand at many vulnerable spots and will offer good protection during this event. The bad news is that the long range forecast charts are predicting another large swell in a weeks time. If that swell were to materialise then it will be a very different situation. The sand lost during tonight and tomorrow night will leave beaches at a far greater risk of erosion.

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