News agency, Cape Town, South Africa
Tuesday October 17th 2017

Cape Town dune defences “increasingly artificialised”

Peter Luhanga

Property development in Cape Town’s northern regions had escalated to such an extent that the coastal dune system has been compromised in its ability to act as a natural buffer system in the event of storm events.

This emerged at a Blaauwberg sub-council meeting held last week (19/02/2009), which discussed coastal strategy and dune management between Melkbostrand and Milnerton.

In a presentation to the meeting, City of Cape Town Coastal Coordinator Darryl Colenbrander said the coastline was “increasingly artificialised” as a result of development.

The “hotspots” where dunes were effectively being cut-off were the Blaauwberg region, Strand, Hout Bay and along Baden-Powell Drive.

The flattening of dunes for development had resulted in only a narrow remaining stretch of dunes, which could not act as a buffer against storm surge events.

He said in the past dune systems had extending inland for up to one kilometre, but in developed areas this had been reduced to 10 metres at most.

Colenbrander said with the dunes being cut-off the potential for the ecosystem to offer a buffer “has been lost or was being lost”. As a result, infrastructure was at risk from storm surge events.

A 2008 study commissioned by the City of Cape Town that looked into the threat of sea level rise as a result of climate change found that there was a likelihood of an increase in violent storms along the City’s coastline in coming years.

Commenting on the City’s dune system, Dr John Compton, from the Department of Geological Sciences at the University of Cape Town (UCT), said development should be managed properly so that people were not allowed to build “like they have done at Big Bay”.

He said the City needed to be vigilant in its coastal management plans and make sure that building plans were not approved in beachfront areas.

Compton said the impact of development on the dune system needed to be considered, with building only allowed on the landward side of the dune system.

“Pretty as the beaches are it’s not a suitable environment to build permanent structures.”

He said dune management was a “huge problem” as in some cases dunes had been measured to move five to ten metres a year. –West Cape News.

Tags: blaauwberg, capetown, dunes

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