Posted by: Saving Water SA (Cape Town, South Africa) – partnered with Water Rhapsody conservation systems
03 February 2010
Sixteen prime coast areas, including Milnerton Harbour, Green Point, Sea Point, Camps Bay and the entire Strand beachfront are at “high risk” from rising sea levels, says the City of Cape Town’s latest sea-level risk assessment.
If sea levels rise, as they are predicted to do in the next 25 years, billions of rands of coastal infrastructure will be damaged.
In a report submitted on Tuesday to the planning and environment portfolio committee, Darryl Colenbrander of strategy and planning, said the sea level risks can no longer be viewed as something to be addressed in the future but must be considered as a priority in city planning.
The weak outcome of the Copenhagen climate conference and apparent inability worldwide to reduce carbon emissions meant that a global temperature increase of at least 3°C was likely, he said in the report.
Higher temperatures would have “multiple implications” for Cape Town as a coastal city. The areas identified as “highly vulnerable” to sea-level rise events are Blouberg Bay, Table View beachfront and Milnerton beach and harbour.
On the Atlantic Coast: Green Point, Sea Point, Glen Beach, Camps Bay, the cottages at Bakoven, Kommetjie and Witsands will be affected. Glencairn, Kalk Bay, Baden Powell Drive, Monwabisi and Macassar pavilions, Strand Beach front and Bikini beach on the False Bay coast will also be hit by sea-level changes.
Research already done for the city on sea levels predicted an 85 percent chance of a 4.5 metre storm surge sea-level rise in the next five years, which would cause about R20 billion damage to infrastructure.
The city council is responsible for 307km of coastline which provides social and economic opportunities. These include recreational opportunities and amenities, as seen at Monwabisi Beach, and housing and development opportunities.
The first three phases of the city’s risk assessment looked at various scenarios of sea-level changes, with specialists determining its impact on the city. The third phase quantified the risks and the potential cost of sea-level changes on coastal systems, recreational space, infrastructure and beachfront property, and the impact on the city water and landfill services.
A detailed assessment of the risk and the cost to the city and residents over the next five to 100 years was done.
The fourth phase looked at a range of mitigation and management measures that would lower the city’s risk profile. Suggestions included ways of improving the city’s ability to accommodate sea-level rise by considering the threat as part of its long-term plan for further development.
The recently completed fifth phase improved the accuracy of determining which areas are most likely to be affected. Specialists analysed the direction of swells and the influence of natural barriers such as kelp forests in reducing storm impact.
Source: Cape Argus