Friday night saw almost 3 inches of rainfall in Kirstenbosch Botanical Gardens in Cape Town. Still, the Cape Town City Council is said to be entertaining the possibility of towing an iceberg from Antarctica to Cape Town, to further help boost the city’s low water inventory. Say what? Can that possibly work? was my first reaction.
Well, here are the numbers*. Some 200 billion tons of ice from Antarctica slide into the sea in a typical year – the equivalent of more freshwater than the world uses in a year. Some icebergs float for 5 years in the ocean, and some make it to Gough Island. Such an iceberg could be towed from there, for the roughly 2,700 km (1,700 mi) distance to Cape Town. The iceberg will be stationed off the coast (Cape Columbine on the west coast is mentioned), and could conceivably deliver 100 megaliter of water every day for a year as it melts. (About 20% of the city of Cape Town’s needs). If such a project is can be pulled off successfully, its cost is projected to be less than half the cost of desalinating an equivalent amount of seawater.
*From an article in the Sat Jun 2 issue of ‘Die Burger’ newspaper.