Cape Town prepares for rising sea levels

13 May 2008

The City of Cape Town is undertaking an in-depth study into the predicted impact of rising sea levels on the city’s vast coastline, so as to identify risks and begin planning for strategies to minimise the implications of climate change.

Various scenarios as to how changes in tidal movements and increased storm events may impact on rising sea levels were presented during a meeting of the city’s planning and environment portfolio committee, with the modelling being done to determine the possible impact on the city’s infrastructure.

“The aim of the Sea-Level Rise Risk Assessment is to predict the ramifications of sea-level changes as a result of climate change on existing coastal systems,” committee chairperson Brian Watkyns said at the meeting attended by city councillors.

This will in turn help guide coastal development and enable the [municipality] to develop long-term adaptation measures for high-risk areas.

“With over 307 km of coastline, the city has the longest stretch of sea frontage of any metropolitan authority in South Africa,” he said. “As such, it is particularly vulnerable to global climate change predictions which will result in a rise in sea levels and an increase in the intensity and frequency of storm events.”

The predicted implications of climate change are modelled on existing information and internationally accepted predictions of future scenarios.

Worst-case scenario

The model portrays what could be expected as current day worst-case storm events, increased storm intensity and frequency as a result of climate change within 10 years and finally the long-term inundation implications if the Antarctic and Greenland ice-sheets melt.

Examples of some of the high risk areas presented to the portfolio committee in Cape Town were those situated mainly in low lying areas or close to estuaries and include Milnerton Lagoon, Fish Hoek, Strand, Gordon’s Bay and Sea Point.

According to Gregg Oelofse of the city’s strategy and planning department, the model made use of data from the extreme storm event experienced along the KwaZulu-Natal coast in March 2007.

“The erosion damage in the province was spectacular and similar damage should be anticipated along exposed sections of the Cape Town coast in similar circumstances,” he said. “The identification of these vulnerable sections of the Cape Town coast is an important output.”

Source: BuaNews