Langebaan beaches sinking into the sea

July 18, 2013 by: admin

Cape Town – While the City of Cape Town has been working on salvaging what is left of nudist beach Sandy Bay, the beach is only one of many along the Western Cape coastline that is quickly losing sand and disappearing into the ocean.

The construction of barriers and groynes has done little to slow down the rapid erosion of the province’s sandy coastline.beaches eroding

On the West Coast, Langebaan Ratepayers’ Association chairperson Jaco Kotze said the beaches were also under serious threat, despite the local municipality spending more than R43-million to build a set of groynes to protect them.

“That was money wasted. The problem is nobody knows why the sand is disappearing so quickly,” Kotze said.

Over the past 30 years he has watched as the large beaches around the lagoon have been reduced to strips of sand. Dredging in the late 1970s to build a breakwater at nearby Saldanha Harbour had dramatically altered the distribution of sand in the lagoon. Since then, the lagoon had been steadily swallowing up beaches.

In 1996, it became clear that Langebaan’s popular main beach would disappear completely unless something was done, and a pair of groynes, designed to interrupt the flow of water, were built.

beaches eroding3While Kotze admitted the project had stopped the sand erosion on that section of beach, it only seemed to speed up the process elsewhere.

Kotze pointed out how large parts of Langebaan’s main beach had disappeared, while the area’s own Sandy Bay was getting smaller every year.

On this beach the water had even begun to break down a set of concrete steps leading down to the lagoon.

“The beachfront houses here are in big trouble.”

Local subsistance fisherman Freddie Makka, 80, who has been fishing in the area for nearly 70 years, said he had also noticed changes to the lagoon’s seabed since dredging began.

“You can’t fish here anymore, it’s become too shallow and most of the fish have disappeared.”

Kotze said he had been working closely with local coastal engineer Anton Fonk, but they had not been able to work out why the erosion was speeding up.

“The main problem here is that nobody has taken the time to analyse the lagoon and the way sand is being moved around.”

What Kotze is certain of is that the groynes did not work. Large sections of them have been dismantled by the incoming waves, and the sand on the main beach is once again starting to erode.

Kotze said in the meantime it was important that development on the beachfront be put on hold.

“It could be that these developments are to blame for what we are seeing. What we need is time, time to monitor the problem and come up with a proper solution.”

Kotze is challenging the development of houses along Shark Bay’s beachfront.

Provincial environmental affairs spokesman Aziel Gangerdine said halting the development could only be decided in terms of a legislative process. This would require public participation and input from the affected stakeholders.

Meanwhile, drastic action is being taken to salvage Sandy Bay near Llandudno.

The popular nudist beach has been steadily losing sand for years.

Mayoral committee member for economic, environmental and spatial planning Garreth Bloor announced that 25 000m3 of sand was being taken from Hout Bay to Sandy Bay as a last-ditch effort to try to replenish the beach’s stocks.

The city’s head of environmental policy and strategy, Gregg Oelofse, said the situation in Sandy Bay was the result of Cape Town’s intricate sand transportation system being interrupted by urban development.

Historically sand would be blown from Hout Bay beach over the mountain and eventually been deposited at Sandy Bay.

But with developments built across the sand’s natural route, the sand had been building up on Hout Bay’s beach.

He said the interruption to the sand transportation system could have the same ramifications for other beaches on the Atlantic seaboard, where some of the beaches were already decreasing in size.

Sandy Bay is just one of many beaches that is slowly losing its sand.

In 2008 it was reported that Plettenberg Bay’s Lookout beach was being swept away by flash floods and high tides.

Oelofse said there had also been substantial erosion of Table Bay over the past 20 to 30 years.

“There isn’t just one factor behind the erosion.

“Sometimes the smallest thing can drastically alter the shape of the coastline.”

He admitted that erosion was inevitable, and it was important to accommodate the sand transport system when it came to new developments.

 

Disappearing beach points to climate change

Last year, London’s Telegraph newspaper reported that Australia’s Kingscliff Beach had disappeared.

Erosion over the years had caused what was once a 60m-wide stretch of sand, frequented by surfers and tourists, to be swept out into waters to the north.

The paper reported that scientists were baffled by the beach’s disappearance, but they believed that the culprit was probably a change in weather conditions.

Of 309 regularly frequented stretches of surfing coastline, 38 had beaches that had shrunk to 25m or less.

Scientists said it could take a decade or more for the beaches that had been swept away in Australia to be naturally restored – and even this was not a certainty.

Professor Roger Tomlinson, one of Australia’s leading experts on coastal erosion, said the shifting sands seemed to be triggered by storms and subtle shifts in the wave direction.

“We also think we are having a situation of more energetic wave conditions, possibly caused by warmer waters offshore,” he said.

The professor warned that other beaches could vanish as well.

The beach’s disappearance left tour operators and lifesavers confused over what to do next, as their livelihoods were washed away with the sand. – Cape Argus

source http://www.iol.co.za

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