Coastal erosion threat


November 25, 2013

Anthony Brennan, who owns a property by the beach at Seabird 100 kilometres north of Perth, says “it’s us against the coast”.

Mr Brennan says a combination of high tides and storm surges has eroded the coastline near his property.

“We have certainly lost two sand dunes in the last 20 years,” he says.

“We go from having a beach of two metres wide to a beach that is 20 metres wide.”

Mr Brennan says the sand on the beach comes and goes, but when the dune goes it’s gone forever.

“The problem in Seabird is more acute [than elsewhere],” he says.

“There are four multi-million dollar houses that are on the verge of being condemned.”

Curtin University Urban and Regional Planning professor Gary Middle says Western Australia is experiencing two main impacts of climate change – rising sea levels and increased storm activity.

“We are seeing a rise in sea levels of almost a metre between now and the end of the century that is called chronic sea level rise which is due to the expansion of oceans through the melting of the glaciers,” he says.

He says the winter storms Perth receives are becoming more frequent and powerful, which is a leading factor in increased coastal erosion.

Professor Middle says some beaches are more vulnerable than others depending on their location.

“Beaches like South Beach south of Perth are pretty vulnerable,” he says.

“Some of the beaches like Quinns north of Perth are also at greater risk.”

Professor Middle says there are currently only a few properties around Seabird that are vulnerable to the combined affects of sea level rise and increased storm activity.

There is no exact explanation as to why these areas are more vulnerable than others but Professor Middle says it could have something to do with the shape of the coastline.

City of Wanneroo Project Planner Jordan Koroveshi says it is hard to assess how long it will take for the beaches named by Professor Middle to become vulnerable.

He says the affects of climate change will vary from place to place depending on location and beach structure.

“Each beach would be affected by climate change and sea level rise at different rates and in different ways,” he says.

“It is difficult to say if this erosion is caused by climate change, or if it is in response to the interruption of sediment drift caused by the installation of the marina and groynes especially in the case of Two Rocks.”

Professor Middle said Rockingham and Busselton, both south of Perth, would also be vulnerable to rising sea levels in the near future.

Photos by Dushyant Mann

1 reply »

  1. About 35 years ago Sorrento beach was the same the water use to come up to the stairs, the shire put groins in this stopped the waves eroding the shore line. The Hillarys boat harbour is there also but that has changed the beach a lot, the glow of ocean has made the beach full of seaweed and the water use to be beautiful and clear niw it is quite merky. So groins are the ways to go.

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