In efforts to help alleviate Cape Towns water crisis, scientists have turned their attention to the Antarctic and the concept of ‘iceberg hunting’. Among these academics is South African marine salvage expert Nick Sloane, who in 2013 help refloat the massive Costa Concordia wreck in the Mediterranean. By making use of these buoyant behemoths Icebergs Cape Town could tap into roughly 1oo million litres of water a day. The cost of the operation comes in at about R1.6 billion.
So far both academics from the University of Cape Town as well as engineers have been assessing the viability of the proposed project. Dr. Chris von Holdt of Aurecon (an engineering consulting firm) has assessed the project from both an economic and technical aspect states that:
“the iceberg proposal sufficient technical feasibility and economic merit to be considered seriously as a supply option for filling the supply gaps during periods of drought.”
Annually over 2,000 billion tons of ice – in the form of icebergs- detach from the Antarctic ice-shelf. Once adrift they are carried by ocean currents until they melt in warmer water. Among these chunks of ice bobbing in the ocean, only 7% are suitable for harvesting, according to Norwegian glaciologist Dr. Olav Orheim. Scientists aim to target specific icebergs with steep sides and a flat top, with a thickness of between 200 and 250 metres.
In order to haul these floating water coolers to the Cape, the project would need to make use of some of the most powerful tugboats in the world – like the ALP Tug, which can pull 300 tonnes.
Going on the assumption that these icebergs would be ‘caught’ westward of South Africa, the combined power of the Circumpolar and Benguela currents, as well as the Coriolis effect, could be utilized in order to help float it towards South Africa reducing the towing power required.
The one the thing the project was missing up until now was an investor. Now that one has been acquired the next step is a signed agreement by June 30th wherein the relevant authorities would agree to buy the ‘iceberg water’ and ultimately trigger the start of the project.
One of the last hurdles to overcome, as with most projects in South Africa is politically based. As Sloane puts it: “The trouble is, no one wants to put their political career on the line by saying yes to an iceberg”. Once Sloane has submitted a detailed costing proposal of what the final price of water obtained through the project would be then and only then will take a more in-depth look at the proposal.
The estimated cost currently stands at around R28 to R35 a kilolitre, or 2.8c to 3.5c a litre, compared to a short-term desalination project, which sits between R52 to R57 a kilolitre.
“If we can get an 80-million ton iceberg and can harvest 70% of it, then we will get 150 million litres a day for a full year. After our initial introduction, we asked people what chance they thought we had of success, and they said less than one percent. By the end of the presentation, they had changed to say between 70% or 90% chance of success. The more they heard, the more credibility they gave the proposal,” said Sloane.
The hope is to source an iceberg off Gough Island (2 700km southwest of Cape Town) and relocate it to roughly 40km offshore of Lamberts Bay where it will be anchored. From here the plan is to dig out a pool to collect the meltwater which would then be pumped onto tankers at a single mooring. The water would then be pumped ashore through an undersea pipeline where it will be stored, temporarily.