In an interview conducted by News24, Nick Sloane, a South African marine salvage expert, is reveals he is hatching a plan to tow icebergs to Cape Town in an effort to ease the strain on the City’s water resources during the current water crisis.
Engineers and academics of the University of Cape Town have been assessing Sloane’s plan, and it has generated enough interest among experts for Sloane to host a seminar on the project in Mid-May.
Calculations have shown that more than 2 000 billion tonnes of icebergs break off the Antarctic ice shelf each year. These pieces of iceberg drift with the ocean current and melt in warmer waters. The Southern Ice Team, who form part of Sloane’s team, hopes to capture icebergs that have drifted northward of Gough Island (located 2 700 kilometers south west of Cape Town).
The Norwegian Polar Institute said that of the 271 000 icebergs analysed between 1993 and 2005, only 7% would be suitable for the purpose of easing the strain on the City’s water resources.
The iceberg must be tubular in shape, and also have a flat top with steep sides. It must also be between 200m and 250 thick. Once an iceberg has been assessed and deemed suitable, it will be captured. This entails two tugs encircling the iceberg, which will then cover the iceberg in a massive piece of geotextile. This material will cover the sides of the iceberg. It will be towed by a tanker, with a third tug as a back up. A distance of 1.5 kilometers will be kept between the tanker and the iceberg.
The destination for the iceberg will be Cape Columbine, which is located just north of Saldanah Bay, where it will be moored in a similar fashion to that of an offshore oil rig.
Although the idea of using an iceberg to supplement water resources has been proposed, it it till unclear as to how a useable form of water will be gathered from the iceberg. Fresh water can be yield from the surface of the iceberg simply by melting it, but capturing the harnessed water is a challenge. Many ideas, however, have been proposed on how to go about this.
It is estimated that 30% of the iceberg would melt during the towing process alone.
The advantage of making use of an iceberg scheme is that it can be used when there is a need for water, and simply discontinued when there is not.
The price of pure Antarctic water will cost around R30 per kiloliter, and is not as large a capital investment as investing in desalination plants.
When approached for comment, the City Council said that it would not consider the iceberg proposal as a new water supply scheme, as it is too risky and complex.