Harvesting icebergs to save the Mother City

Harvesting icebergs was one of the solutions offered to assist with the water shortages in Cape Town. At the African Utility Week Conference, held in the Mother City in May, Peter Flower, director of water and sanitation in the City of Cape Town, told delegates that the City still needs to reduce water consumption (to 450-million litres per day) to keep Day Zero at bay. With the current usage (of 500-million litres per day) the situation remains dire.

According to salvage expert Nick Sloane, the answer to the water crisis might lay buried in icebergs – a total of
140 000 icebergs to be exact – that are drifting in the southern oceans. Harvesting icebergs, he said, could help provide at least 20 percent of Cape Town’s water needs.

Icebergs, which contain some of the purest quality water, break off in Antarctica, drift into the ocean and melt away. Sloane noted: “About two-billion tonnes of ice breaks off every year.” He envisages these icebergs being captured around Gough Island in the South Atlantic Ocean, and then guided and moored about 40 km off the island of St Helena, where the water could be harvested.

Sloane explained that large saucers would have to be used to capture the melting water. It is estimated this could deliver up to 60-million litres of water per day. By milling the iceberg, this could increase to 150-million litres of water a day, which could be pumped into tankers and ferried to land, where it would be treated before going into the water system in Cape Town.

When asked whether this system would be financially viable, Sloane said: “We are looking into it.”

Claire Janisch, director of BiomimicrySA, shared case studies on how nature can be copied to help mitigate the increasing challenges related to natural resources.

She explained that wind turbines can be made more efficient by looking at the attack manoeuvres of the humpback whale, while mangrove trees, which survive on sea water, can teach us something about desalination.

“Solutions to our problems already exist in nature. We can improve our physical world by following nature’s example,” Janisch concluded.