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Could icebergs help Cape Town avoid Day Zero?

Posted at 9:21 AM, May 02, 2018
and last updated 2018-05-02 09:21:27-04

Cape Town may have narrowly avoided Day Zero -- the date at which the South African coastal metropolisof 4 million people would run completely out of water -- but the extreme water crisis it's facing is far from over.

Draconian water restrictionsremain on the city's residents, limiting their water usage to 50 liters a day per person, and if significant winter rains do not replenish the region's reservoirs, Cape Town will once again be faced with prospect of taps running dry in early 2019.

With desalination efforts proving to be time-consuming and costly, unconventional water supply options are under consideration.

 

 

One unique idea comes from noted salvage master Nicholas Sloane, who believes it's feasible to harness an iceberg that has broken off from Antarctica and tow it to the coast of Cape Town, where it would melt into usable water.

Sloane, a South African, is known for leading themonumental salvage operation of the capsized Italian cruise ship Costa Concordia in 2013.

"We spoke to local government late last year; they thought it was a crazy idea," Sloane told CNN on Tuesday.

But Sloane said that geography could be the key to the success of the project.

Antarctica shreds nearly 2,000 billion tons of ice per year, and many massive icebergs drift within about 1,200 miles of South Africa.

A single iceberg, weighing about 70,000 tons, would be enough to provide nearly 150 million liters of water per day for a year, according to Sloane.

He said it would meet nearly one-third of Cape Town's water needs, considerably more than desalination and other emergency plans the city is currently pursuing.

But the process wouldn't be an easy one.

The iceberg would likely be around a kilometer (0.6 mile) in length and would need to be wrapped in a fabric to limit the amount of melting that would take place on the three-month journey that a trip to Cape Town would require.

The idea is for a large tanker to guide the wrapped iceberg into the Benguela Current, which flows up from the Antarctic Circumpolar Current, along the west coast of South Africa.

Even so, it is estimated that about 30% of the iceberg's mass would melt before it reaches its destination.

Because icebergs have such massive draft, it would likely run aground many miles off the coast, but Sloane and his team have a plan to moor it just offshore and harvest the meltwater from an opening inside the berg.

Fortunately, the ice is pure water, and would require minimal processing before being delivered to Cape Town residents.

It would be a significant advantage over other options under consideration such as capturing water from the heavily polluted Congo River and bringing it to Cape Town in supertankers.

In an interview with "CapeTalk" radio host John Maytham, Sloane said, "The cost (of transporting and treating water from the Congo) does not warrant that kind of action," adding that it may only be good for gray watereven after treatment.

Harvesting water from icebergs is not a new idea -- it was first floated in academic circles in the 1970s.

A company in the United Arab Emirates was also planning on towing Antarctic icebergs more than 5,700 miles (9,200 kilometers) through the Indian Ocean to the UAE coast to help alleviate the water needs of the desert nation.

But the major engineering hurdles and large costs have so far prevented the idea from taking shape.

There are also some environmental concerns.

A review of the idea in a 2001 special report from the International Water Resources Association found that "melting iceberg material in near-shore coastal waters could cause a dramatic decline in local water temperatures with probable associated adverse effects on sensitive marine organisms."

But Sloane said he feels his team can succeed in the venture, and he plans to hold a meeting on May 17-18 to try to sell the $130 million project to Cape Town officials and investors.

Sloane said he is already 80% of the way to his funding goal and would like the effort to be completely privately funded, without any capital needed from local or the national government.

If he gets a green light at the meeting, Sloane said he hopes to begin work immediately.

"We believe we can do it," he said, adding that the project could be producing about 150 million liters a day by this time next year.