Cape Town, like other areas in South Africa, has been going through a dry spell for an extended period now. The situation has left residents with severe water shortage, and the city’s officials are currently thinking of new ways find clean, fresh water.
Among the proposals put on the table is the idea to send tankers down south to Antarctica and lasso a giant iceberg then haul it northwards to the shores of Cape Town. Once the iceberg makes it to the shores, it will then be chipped off into small pieces, filtered and then pumped to people’s houses.
A climate scientist at the University of Cape Town, Peter Johnston, says while the city officials are not officially considering the idea, he thinks it is very viable. Johnston says Cape Town can get an iceberg 100 million tons (91 million metric tons) in size within a thousand miles south towards Antarctica.
The iceberg could be harnessed using a big belt and then towed across the ocean slowly by a tanker; it could also be towed using ocean currents and even kite sails. Once it docks at the Cape Town shores, a lattice steel structure fitted with plastic could be used to capture the fresh water and then pumped into pipes. After the water is filtered and treated, it could then be channeled into the city’s main water supply system.
“If we did get one of these medium-sized icebergs, we’re at supplying about 20 percent of the city’s water needs per day at a cost of about a dollar per each 100 gallons (378 liters),” said Johnston.
The idea of hauling an iceberg from the deep dark fringes of the ocean was not first presented by Cape Town. A similar proposal was presented by another firm based in Abu Dhabi who wanted to relieve the chronic water shortage in the United Arab Emirates by towing 20 billion gallons (76 billion liters) iceberg to the coast of Fujairah.
The firm said once the iceberg gets anchored in the coastal town located on the east coast of Gulf of Oman, it would meet the need of one million people for the next five years. It will also be a source of tourist attraction and thereby creating a source of income for the local economy. Not to mention the micro-climate the iceberg will create in the area leading to rainfall being experienced.
Check out the video presentation by the firm below.
The logistics and cost of hauling an iceberg across the ocean waters is too great
Even a little iceberg is enormous and has a massive mass; most of it below the water surface. It easily dwarfs even the biggest navy ships and attempts to tow it across the ocean would require billions of dollars not to mention the carbon footprint of the entire affair.
There is, of course, the matter of water forming as you move the iceberg from the cold into the warmer regions. The surface will start melting leading to a massive pool of water building at the top of the surface. This water could easily lead to the ice cracking and the entire iceberg disintegrating into smaller pieces, which will be harder to haul.
The ideal iceberg to haul would be those that come in tabular shapes, yet these types present a big drainage issue once their surface starts melting. The closest humans can come to hauling an iceberg would be to wrap the iceberg with an insulating skirt to reduce melting, but that will drive up the cost tenfold.
Zero Carbon footprint transportation of the iceberg
Financing the project of hauling icebergs across the ocean might be unsustainable for many countries, not to mention the huge carbon footprint left behind. However, there is another option that will require significantly less money, called Kedging.
If you are not a sailor, you might not be familiar with kedging, but it’s an 18th-century nautical concept that leverages on the natural tidal forces. It would require anchoring an iceberg to a base slab using cables. When the tide pushes the iceberg away from its destination, the anchor would hold it in place. When the tides change and start pushing it towards the desired direction, the anchor will be let loose and allow the iceberg to drift with tidal forces towards its destination.
Kedging could ideally move a large mass of iceberg without using any motor powers, although it will be significantly slow.
However, Cape Town officials have not signed onto the idea of towing an iceberg to shores, but the idea presents a reasonable solution to the city’s current water shortage; albeit it is thinking too far outside the box.